CN118369851A - Piezoelectric device - Google Patents

Abstract

The piezoelectric device includes a piezoelectric element, a mounting base, and a temperature sensing element. The mounting base includes a recessed portion sealed airtightly. The piezoelectric element is mounted on the bottom surface of the recessed portion. The temperature sensing element includes a portion located closer to the upper end side of the recessed portion than the piezoelectric element.

Description

Piezoelectric Devices

Technical Field

The present disclosure relates to piezoelectric devices.

Background technique

Piezoelectric devices such as crystal resonators and crystal oscillators are known (for example, refer to the following patent document). Such a piezoelectric device has a piezoelectric element and a package that holds the piezoelectric element. The piezoelectric element has a piezoelectric body (for example, a crystal blank), two excitation electrodes overlapping the piezoelectric body, and two extraction electrodes led from the two excitation electrodes. The two extraction electrodes are bonded to the pads of the package, for example, by a conductive bonding material, thereby facilitating the mounting of the piezoelectric element relative to the package.

As the piezoelectric device as described above, there is known a device having a temperature sensing element such as a thermistor. The temperature detected by the temperature sensing element is used, for example, to compensate for a change in the characteristics of the piezoelectric device caused by a temperature change.

The temperature sensing element is mounted on the package. For example, in Patent Document 1, the package has a first recess and a second recess opened on the side opposite to the first recess. The piezoelectric element is accommodated in the first recess and mounted on the bottom surface of the first recess. In addition, the first recess is sealed by a cover. The temperature sensing element is a chip-type component, which is accommodated in the second recess and mounted on the bottom surface of the second recess. Specifically, the two terminals of the temperature sensing element are bonded to the two pads located on the bottom surface of the second recess by a conductive bonding material.

Prior Art Literature

Patent Literature

Patent Document 1: Japanese Patent Application Publication No. 2011-211340

Summary of the invention

A piezoelectric device according to one embodiment of the present disclosure includes a piezoelectric element, a mounting base, and a temperature sensing element. The mounting base includes a recessed portion that is sealed airtightly. The piezoelectric element is mounted on the bottom surface of the recessed portion. The temperature sensing element includes a portion located closer to the upper end of the recessed portion than the piezoelectric element.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view showing a crystal resonator according to a first embodiment.

FIG. 2 is another exploded perspective view showing the crystal resonator of FIG. 1 .

FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1 .

FIG. 4A is a plan view showing another example of the external electrode of the temperature sensing element.

FIG. 4B is a plan view showing still another example of the external electrodes of the temperature sensing element.

FIG. 5A is a cross-sectional view showing another example of the position of the temperature sensing element.

FIG. 5B is a cross-sectional view showing still another example of the position of the temperature sensing element.

FIG. 5C is a cross-sectional view showing still another example of the position of the temperature sensing element.

FIG. 6 is a perspective view showing another example of the shape of the temperature sensing element.

FIG. 7 is a cross-sectional view of a crystal resonator according to the second embodiment.

FIG. 8 is a cross-sectional view of a crystal resonator according to a third embodiment.

FIG. 9 is an exploded perspective view showing a crystal resonator according to a fourth embodiment.

FIG. 10 is another exploded perspective view showing the crystal resonator of FIG. 9 .

FIG. 11 is a cross-sectional view taken along line XI-XI of FIG. 9 .

FIG. 12A is a plan view showing another example of the element terminal of the temperature sensing element.

FIG. 12B is a plan view showing still another example of the element terminal of the temperature sensing element.

FIG. 13 is a plan view showing still another example of the element terminal of the temperature sensing element.

FIG. 14A is a cross-sectional view showing another example of the shape of the temperature sensing element.

FIG. 14B is a cross-sectional view showing still another example of the shape of the temperature sensing element.

FIG. 15A is a cross-sectional view showing another example of fixing the temperature sensing element and the mounting base.

FIG. 15B is a cross-sectional view showing still another example of fixation between the temperature sensing element and the mounting base.

FIG. 15C is a cross-sectional view showing still another example of fixation between the temperature sensing element and the mounting base.

FIG. 16 is a perspective view showing a specific example of wiring in a package.

FIG. 17 is a perspective view showing another specific example of wiring in a package.

FIG. 18 is a plan view showing still another specific example of wiring in a package.

FIG. 19 is a schematic diagram showing an example of use of the crystal resonator according to the embodiment.

Detailed ways

Hereinafter, the embodiments of the present disclosure will be described with reference to the accompanying drawings. The figures used in the following description are schematic diagrams. Therefore, for example, the dimensional ratios on the drawings may not be consistent with the actual dimensional ratios. The dimensional ratios of the same components are also inconsistent between the drawings. In addition, sometimes the illustration of the details is omitted, and the shape of a part is exaggerated. However, the above content does not deny that the actual dimensional ratios are as shown in the drawings, and that features such as shape and dimensional ratios can be extracted from the drawings.

In the accompanying drawings, for convenience, an orthogonal coordinate system D1-D2-D3 is sometimes marked. The piezoelectric device involved in the embodiment can also be set in any direction as the up-down direction or the horizontal direction. However, for convenience, the +D3 side is sometimes set as the top. In addition, unless otherwise specified, a top view or a top perspective view refers to an observation parallel to the D3 direction.

In the description of the method (implementation method and other examples) described relatively later, basically only the differences from the method described previously are described. Matters not specifically mentioned can be the same as or by analogy with the method described previously. As long as no contradiction occurs, the description of the method described previously can be referred to the method described later. As long as no contradiction occurs, the description of the method described later can also be referred to the method described previously. In multiple methods, for the sake of convenience, for components corresponding to each other, the same figure mark is sometimes marked even if there are differences.

The term "side" as a term referring to the edge of a planar shape generally refers to the edge of a polygon (in other words, a straight line), but in the description of the embodiment, for convenience, it is sometimes used for the edge of a shape that may not be a polygon (for example, it may be a curved edge). Similarly, "long side" and "short side" generally refer to the sides of a rectangle, but in the description of the embodiment, for convenience, it is sometimes used for the edge of a shape that may not be a rectangle (however, the shape of four edges can be conceptualized) or a portion similar to an edge. "Parallel" generally refers to a relationship in which the distances between straight lines are fixed, but in the description of the embodiment, for convenience, the relationship in which the distances between lines that are not straight lines (such as curves) are fixed is sometimes used. When referred to as a rectangle or a rectangular shape, unless otherwise specified, the corners may be chamfered, etc., and it may not be a strict square or a narrow rectangle. The same applies to polygons other than rectangles.

<Overview of Embodiment>

Fig. 1 is an exploded perspective view showing the structure of a crystal resonator 1 (hereinafter, the term "crystal" is sometimes omitted) according to an embodiment (more specifically, the first embodiment). Fig. 2 is an exploded perspective view of the crystal resonator 1 viewed from the opposite side to Fig. 1. Fig. 3 is a cross-sectional view taken along line III-III of Fig. 1.

The resonator 1 is, for example, a surface-mounted chip-type electronic component. Specifically, the overall shape of the resonator 1 is a roughly thin rectangular parallelepiped (a shape in which the dimension in the D3 direction is smaller than the dimension in the D1 direction and the dimension in the D2 direction). In addition, on the lower surface of the rectangular parallelepiped, four layered terminals 3 are provided at the four corners. The four terminals 3 are connected to the unillustrated pads of the circuit substrate 53 (see FIG. 19 described later) through a conductive bonding material (e.g., solder), whereby the resonator 1 is fixed and electrically connected (i.e., mounted) to the circuit substrate 53.

The resonator 1 has a crystal element 5, a temperature sensing element 7 (FIG. 2 and FIG. 3), and a package 9 (see FIG. 3 for reference numerals) for holding these elements (5 and 7). The crystal element 5 vibrates, for example, by applying an AC voltage through two of the four terminals 3. The vibration is used, for example, to generate an oscillation signal that vibrates at a fixed frequency with respect to the intensity of the signal (e.g., voltage or current). The frequency of the oscillation signal is arbitrary. The temperature sensing element 7 outputs a signal corresponding to the temperature through the other two of the four terminals 3. The signal is used, for example, to compensate for changes in the characteristics of the crystal element 5 with respect to temperature changes.

The package 9 constitutes the outer contour of the resonator 1 and has the above-mentioned terminals 3. In addition, the package 9 has, for example: a mounting base 11 having a recess R1; and a cover 13 that seals the recess R1. The crystal element 5 is accommodated in the recess R1. Moreover, the upper surface opening of the recess R1 is sealed by the cover 13, thereby forming a closed space (airtight sealed space), and the crystal element 5 is sealed. The closed space is set to a vacuum state, or an appropriate gas (such as nitrogen) is sealed. In addition, the mounting base 11 has the above-mentioned four terminals 3 on its lower surface. The crystal element 5 is mounted on the bottom surface of the recess R1. As a result, the crystal element 5 is electrically connected to the two terminals 3.

The temperature sensing element 7 has a portion located between the crystal element 5 and the cover 13. In other words, the temperature sensing element 7 has a portion located on the upper end side of the recess R1 relative to the crystal element 5. Specifically, in the example shown in the figure, the temperature sensing element 7 is composed of a film-like element (for example, a thin film thermistor) overlapping the lower surface of the cover 13 (the lower surface 13b of the cover), and thus the temperature sensing element 7 is located between the crystal element 5 and the cover 13. The electrical connection between the temperature sensing element 7 and the two terminals 3 is achieved, for example, by connecting the temperature sensing element 7 to the mounting base 11 around the opening of the upper surface of the recess R1.

Here, the package 9 is mounted on the circuit substrate 53 (FIG. 19) via the terminal 3 located on the lower surface thereof. Therefore, the heat of other devices mounted on the circuit substrate 53 is easily transferred from the lower surface side of the package 9 via the circuit substrate 53. As a result, for example, if the temperature sensing element 7 is located on the bottom surface side of the recess R1 relative to the crystal element 5, or is located on the lower surface of the package 9, the measured temperature is excessively affected by the external heat, and the measured temperature may deviate from the temperature of the crystal element 5. As shown in this embodiment, by locating the temperature sensing element 7 on the cover 13 side relative to the crystal element 5, the possibility of the above-mentioned phenomenon can be reduced.

In any of the first to fourth embodiments described below, as described above, the temperature sensing element (7, etc.) has a portion located on the upper end side of the recess R1 relative to the crystal element 5. In the first embodiment, as described with reference to FIGS. 1 to 3 , the temperature sensing element 7 is composed of a film-like element overlapping the lower surface of the cover 13. In the second to fourth embodiments (FIG. 7, FIG. 8, and FIG. 9), the temperature sensing element 207 or 407 is an element on the chip side. In the second embodiment (FIG. 7), the temperature sensing element 207 is mounted on the lower surface of the cover 13. In the third embodiment (FIG. 8), the temperature sensing element 207 is mounted on the wall of the recess R1. In the fourth embodiment (FIG. 9), the temperature sensing element 407 is used as a cover for airtightly sealing the recess R1.

The above is an overview of the resonator (1, etc.) according to the embodiment. Hereinafter, the resonator will be described roughly in the following order.

1. First Implementation

1.1. Crystal element

1.2. Package (except for the part involving the temperature sensing element.)

1.2.1. Insulating substrate

1.2.2. Conductors of the mounting base (except for the portion where the mounting base and the cover are joined)

1.2.3. Bonding materials

1.2.4. Cover

1.2.5.Joining of the mounting base and the cover

1.3. Temperature sensing element (including the temperature sensing element of the package.)

1.3.1. Overview of the structure of the temperature sensing element

1.3.2. Correspondence between the structure of the temperature sensing element and the attached figure

1.3.3. Position, shape and size of temperature sensing element

1.3.4. Location, shape and size of external electrodes

1.3.5. Parts of the package’s temperature sensing element

1.4. Other Examples of the First Embodiment

1.4.1. Other Examples of External Electrodes (FIGS. 4A and 4B)

1.4.2. Other Examples of Temperature Sensitive Film (FIGS. 5A to 5C and 6)

1.5. Summary of the First Implementation

2. Second Implementation

3. Third Implementation

4. Fourth Implementation

4.1. Crystal resonator

4.2. Other Examples of the Fourth Embodiment

4.2.1. Other examples of connecting electrodes

4.2.2. Other examples related to the component body

4.3. Summary of the Fourth Implementation

5. Specific example of wiring in package

6. Examples of using crystal resonators

<1. First Embodiment>

(1.1. Crystal element)

The crystal element 5, for example, has a crystal blank 15 (in other words, a piezoelectric body) and two or more (a pair in the illustrated example) conductor patterns 17 (in the illustrated example, two, a first conductor pattern 17A and a second conductor pattern 17B). By applying a voltage to the crystal blank 15 using the pair of conductor patterns 17, the crystal blank 15 vibrates. Thus, the crystal element 5 performs the functions described above. The specific structure of the crystal element 5 can be various structures. For example, the structure of the crystal element 5 can be various known structures.

In addition, in the method of making the crystal blank 15 by etching, due to the anisotropy of the crystal relative to etching, sometimes there is an inclined surface (a crystal surface in other viewpoints) on the side surface, etc. In the description of the embodiment, the existence of such an inclined surface is basically ignored. In the description of dimensions, etc., when strictness is required, as long as the description does not lack rationality or does not cause contradictions, the inclined surface can be ignored or considered. For example, when the length of the D1 direction of the crystal blank 15 is referred to, the length can be the length of the upper surface or the lower surface of the crystal blank 15 (the length excluding the crystal surface), or it can be the maximum length in a top-down perspective (taking into account the length of the crystal surface).

In the example shown in the figure, the crystal element 5 is a so-called AT-cut crystal element. In the AT-cut crystal element 5, the crystal blank 15 has a roughly plate-like shape. In addition, the pair of conductor patterns 17 has: a pair of excitation electrodes 19, which overlap with the two main surfaces (the widest surface of the plate shape, the front and back surfaces of the plate shape) of the plate-like crystal blank 15; and a pair of extraction electrodes 21, which are extracted from the pair of excitation electrodes 19.

A pair of excitation electrodes 19 helps to apply voltage to the crystal blank 15. In the AT cut type, so-called thickness sliding vibration is generated by applying an AC voltage to the crystal blank 15. A pair of extraction electrodes 21 helps to mount the crystal element 5. More specifically, in the example shown in the figure, a pair of extraction electrodes 21 and a pair of pads 25 described later are joined by a pair of bonding materials 29 (FIG. 3), whereby the crystal element 5 is electrically connected and fixed to the package 9, and is further supported in a cantilever beam shape.

As crystal elements other than the examples shown in the figure, for example, the following crystal elements can be cited. A tuning fork-type element utilizing bending vibration. An element utilizing CT cutting or DT cutting using contour sliding vibration. An element utilizing a cutting angle other than AT cutting (for example, BT cutting) using thickness sliding vibration. An element utilizing SAW (surface acoustic wave). In addition, such an element also has, for example, a piezoelectric body (for example, a crystal), two or more excitation electrodes for exciting the piezoelectric body, and two or more extraction electrodes extending from the two or more excitation electrodes. In an element utilizing SAW, the layer of the piezoelectric body may also overlap with a layer composed of other materials.

In the description of this embodiment, for the sake of convenience, it is assumed that the crystal element 5 is an AT-cut crystal element, without particular explanation in some cases.

As shown in the example, in a crystal element 5 (not limited to an AT-cut type) having a plate-shaped crystal blank 15, a pair of excitation electrodes 19 overlapping the two main surfaces of the crystal blank 15, and a pair of extraction electrodes 21 extending from the pair of excitation electrodes 19, a more specific structure (planar shape, etc.) of the crystal blank 15, the excitation electrode 19, and the extraction electrode 21 can be appropriately set.

For example, the shapes of the crystal blank 15, the excitation electrode 19, and the extraction electrode 21 may be formed so that both sides of the crystal element 5 are the mounting side (-D3 side), or may not be formed in such a structure (the example shown in the figure). For example, the crystal element 5 may be formed so that it is approximately 180° rotationally symmetrical with respect to a center line (not shown) extending in the D1 direction (in the example shown in the figure, the long side direction of the crystal element 5), or may not be formed in such a structure (the example shown in the figure).

In addition, for example, the planar shape of the crystal blank 15 can be set to a rectangular shape (the example shown in the figure), a circular shape, an elliptical shape, or a polygon other than a rectangle. In addition, the planar shape of the crystal blank 15 can also be a shape in which any number of sides of the polygon (for example, one side, two sides, three sides, or four sides of a rectangle) are expanded outward in a curved shape. In addition, the planar shape of the crystal blank 15 can also be a shape with a protrusion or a cutout in a portion. In addition, for example, the planar shape of the crystal blank 15 can be a shape with the D1 direction as the long side direction (a shape in which the maximum length in the D1 direction is longer than the maximum length in the D2 direction), or a shape in which such a distinction cannot be made.

In addition, for example, the thickness of the crystal blank 15 may be fixed (the example shown in the figure) or not. As an example of the latter, the following examples can be cited without particular illustration. The central region (table portion) overlapping with a pair of excitation electrodes 19 and excited is thicker than the peripheral region, which is the so-called table type. In contrast to the above, the central region (inverted table portion) overlapping with a pair of excitation electrodes 19 and excited is thinner than the peripheral region, which is the so-called inverted table type. It has: a vibration portion, which is excited by overlapping with a pair of excitation electrodes 19; and a fixed portion, which is adjacent to a part of the edge of the vibration portion (for example, one side, two sides or three sides), is thicker than the vibration portion, and a pair of extraction electrodes 21 are located in the fixed portion. An angled type in which the thickness becomes thinner as it approaches the outer peripheral edge.

In addition, for example, the planar shape of the excitation electrode 19 may be a shape similar to the planar shape of the crystal blank 15 (or the planar shape of the above-mentioned table portion, inverted table portion, or vibration portion. In this paragraph, the same applies below) (the example shown in the figure), or it may not be such a shape. As the former, for example, the planar shape of the crystal blank 15 - the planar shape of the excitation electrode 19 is rectangular-rectangular, circular-circular, or elliptical-elliptical. As the latter, for example, the planar shape of the crystal blank 15 - the planar shape of the excitation electrode 19 is rectangular-circular, rectangular-elliptical, or elliptical-rectangular. Regardless of whether the planar shape of the excitation electrode 19 is similar to the planar shape of the crystal blank 15, the description of the planar shape of the crystal blank 15 can be applied to the planar shape of the excitation electrode 19 as long as no contradiction occurs.

In addition, for example, a pair of extraction electrodes 21 are extracted from the excitation electrode 19 to one end side of the crystal blank 15. More specifically, for example, as if already in contact, although no particular reference numeral is given, each extraction electrode 21 has a wiring portion extending from the excitation electrode 19 and a pad-shaped terminal portion connected to the excitation electrode 19 via the wiring portion. The terminal portion is a portion joined to the pad 25.

In the crystal element 5 utilizing thickness sliding vibration, the thickness of the crystal blank 15 (in this paragraph, unless otherwise specified, it is the thickness of the portion where the excitation electrode 19 overlaps) becomes a factor that determines the frequency of the oscillation signal. For example, it is well known that in AT-cut crystal elements, the relationship of f=1.67×n/t basically holds true. Here, f is the frequency (MHz), n is the number of vibrations utilized, and t (mm) is the thickness. The crystal element 5 can utilize both the fundamental mode and the harmonic mode. As described above, the frequency of the oscillation signal is arbitrary, and furthermore, the thickness of the crystal blank 15 is also arbitrary. For example, the thickness of the crystal blank 15 can be greater than 5μm, greater than 10μm, greater than 30μm, or greater than 50μm, and can also be less than 200μm, less than 100μm, less than 50μm, or less than 30μm. The above lower and upper limits can be combined with arbitrary values without causing any contradiction.

As understood from the description already described, the maximum thickness of the AT-cut crystal blank 15 may be the same as or different from the thickness for specifying the above-mentioned frequency. In any case, the maximum thickness of the crystal blank 15 is arbitrary. The maximum thickness of the AT-cut or other types of crystal blanks (or crystal elements) may be, for example, set to be greater than 30 μm, greater than 50 μm, or greater than 100 μm, and may also be set to be less than 300 μm, less than 200 μm, less than 100 μm, or less than 50 μm. The above-mentioned lower and upper limits may be combined with any numerical values without causing any contradiction.

The material of the conductor pattern 17 may be, for example, a metal. Examples of the metal include nickel (Ni), chromium (Cr), titanium (Ti), gold (Au), or silver (Ag), or an alloy having at least one of these as a main component. The conductor pattern 17 may be composed of a single conductor layer containing a single material, or may be composed of a plurality of conductor layers containing different materials. For example, the conductor pattern 17 may have the same material structure for the entire area, or may have different material structures depending on the area.

(1.2. Package (except for the part involving the temperature sensing element))

The package 9 forms the outer contour of the resonator 1, and its outer shape is a generally thin rectangular parallelepiped. The size of the package 9 (resonator 1) is arbitrary. If an example of a relatively small resonator 1 is given, the length in the long side direction or the short side direction (D1 direction or D2 direction) when viewed from above is greater than 0.6 mm and less than 2.0 mm. The thickness (length in the D3 direction) is greater than 0.2 mm and less than 1.5 mm.

As described above, the package 9 includes the mounting base 11 and the cover 13. The mounting base 11 includes, for example, an insulating base 23 and various conductors located on the insulating base 23. The various conductors include, for example, the terminals 3 described above, two pads 25 (FIG. 1 and FIG. 3) on which the crystal element 5 is mounted, and a plurality of wirings 27 (FIG. 3) that facilitate electrical connection within the package 9. The plurality of wirings 27 include, for example, two wirings 27 that connect the two pads 25 to the two terminals 3.

(1.2.1. Insulating substrate)

The shape, size and material of the insulating base 23 are arbitrary. The insulating base 23 constitutes most of the mounting base 11, and its outer shape (ignoring the shape of the recess R1) is roughly a thin rectangular parallelepiped. The recess R1 opens on the upper surface (the surface on the +D3 side) of the insulating base 23. Although not specifically shown in the figure, when viewed from above, the corners of the insulating base 23 may be chamfered by a flat surface or a curved surface, or have a recess (castle-shaped structure).

The insulating base 23 has a recess R1, and thus can be understood as having a substrate portion 23a constituting the bottom surface of the recess R1 and a frame portion 23b constituting the wall portion of the recess R1. In addition, the insulating base 23 can be manufactured by stacking the substrate portion 23a and the frame portion 23b, or by a manufacturing method different from that manufacturing method. As the former, for example, a method can be cited in which an opening forming the recess R1 is formed on a ceramic green sheet of one layer (or two or more layers) forming the frame portion 23b, and the ceramic green sheet with the opening and the ceramic green sheet of one layer (or two or more layers) forming the substrate portion 23a are stacked and fired. As the latter, for example, a method can be cited in which a recess R1 is formed on a ceramic green sheet of one layer (or two or more layers) by punching and fired. As understood from the latter manufacturing method, the substrate portion 23a and the frame portion 23b (different insulating layers from other viewpoints) may be portions conceptualized for convenience based on the shape of the insulating base 23 and/or the conductor layer in the insulating base 23.

The substrate portion 23a is, for example, roughly in the shape of a flat plate. In other words, the substrate portion 23a has a first substrate surface 23c and a second substrate surface 23d facing the opposite side thereof, and the two surfaces are parallel planes. The first substrate surface 23c constitutes the bottom surface of the recess R1. The second substrate surface 23d constitutes the lower surface of the package 9. The planar shape of the substrate portion 23a is, for example, rectangular corresponding to the outer shape of the insulating base 23 being a rectangular parallelepiped. That is, the substrate portion 23a has a pair of long sides facing each other and a pair of short sides facing each other when viewed from above. In addition, the ratio of the length of the long side to the short side is arbitrary. The thickness of the substrate portion 23a is also arbitrary.

The frame 23b extends, for example, along the edge of the upper surface of the substrate 23a. The shape of the outer edge of the frame 23b when viewed from above is, for example, a shape that is substantially consistent with the outer edge of the substrate 23a. The shape of the inner edge of the frame 23b (the shape of the recess R1 when viewed from above) is, for example, a rectangular shape having four sides that are substantially parallel to the four sides of the outer edge of the frame 23b. The frame 23b has, for example, a fixed thickness. The outer circumferential surface and the inner circumferential surface of the frame 23b are, for example, substantially parallel to the D3 direction. However, unlike the example shown in the figure, for example, the inner circumferential surface of the frame 23b may also be inclined so that the length of the recess R1 increases as it moves upward (+D3 side). In addition, regardless of whether there is such an inclination, as long as there is no special explanation, the shape and size of the recess R1 when viewed from above mentioned in the description of the embodiment may be the upper surface opening of the recess R1 (the inner edge of the upper surface of the frame 23b (frame upper surface 23e)) or the bottom surface of the recess R1 as long as there is no contradiction.

The thickness of the frame portion 23b (the depth of the recess R1) can be appropriately set, for example, according to the thickness of the crystal element 5 and the temperature sensing element 7. For example, the depth of the recess R1 (or the height from the first substrate surface 23c to the lower surface 13b of the cover. The same applies in this paragraph below.) can be more than 1.2 times, more than 1.5 times, more than 2 times, or more than 3 times the total thickness of the crystal element 5 and the temperature sensing element 7 (the interval between the two is not included. In the case where the thickness is not fixed, for example, the maximum thickness). In addition, it can be less than 10 times, less than 5 times, less than 3 times, or less than 2 times. The above-mentioned lower limit and upper limit can combine any numerical values with each other without causing any contradiction. The above-mentioned lower limit and/or upper limit can be used for the depth of the recess R1 in comparison with the thickness of the single body of the crystal element 5.

The width of the frame 23b (the length from the inner circumference to the outer circumference) is arbitrary. In the present embodiment, as described in detail later, the connection electrode 31 (FIG. 1 and FIG. 3) electrically connected to the temperature sensing element 7 is provided on the upper surface of the frame 23b (frame upper surface 23e). Therefore, the width of the frame 23b (and/or the frame upper surface 23e) may also be wider than that of the previous package. In addition, the width may also be set to the same size as before. In this case, for example, by making the width of the sealing material 33 (reference numeral 3 in the drawing) overlapping with the frame upper surface 23e narrower than before, an area for configuring the connection electrode 31 on the frame upper surface 23e can be ensured.

The width of the frame portion 23b and/or the frame portion upper surface 23e (when not fixed, the maximum width or the width of the side where the connection electrode 31 is located) can be set to 1/20 or more, 1/10 or more, or 1/5 or more relative to the length of the long side direction or short side direction of the substrate portion 23a, and can be set to less than 1/3, less than 1/4, or less than 1/5. The above lower limit and upper limit can be combined with arbitrary values without causing contradiction.

The size of the recess R1 when viewed from above can be appropriately set, for example, by considering the size of the crystal element 5 when viewed from above. If necessary, the size of the temperature sensing element 7 when viewed from above can also be considered. For example, when viewed from above, the length of the long side direction (D1 direction) of the recess R1 (for example, the maximum length when it differs depending on the position in the height direction, etc.) can be set to 1.05 times or more, 1.1 times or more, 1.2 times or more, or 1.5 times or more relative to the length of the long side direction (for example, the maximum length) of the crystal element 5. In addition, it can be set to less than 2 times, less than 1.5 times, or less than 1.3 times. The above lower limit and upper limit can be combined with arbitrary numerical values without causing contradiction.

In addition, the shape of the recess R1 when viewed from above may also be different from the example shown in the figure, and may not be rectangular. In another viewpoint, on the upper surface 23e of the frame, the inner edge may not be parallel to the outer edge. For example, it is assumed that the crystal element has an arm for vibration or an arm for mounting. In this case, when viewed from above, the upper surface 23e of the frame may also have a convex portion inserted between the arm and other parts of the crystal element. Such a convex portion can, for example, help ensure the configuration area of the connection electrode 31 connected to the temperature sensing element 7.

The material of the insulating base 23 (substrate portion 23a and frame portion 23b) is arbitrary, and may be, for example, ceramic. The specific type of ceramic is arbitrary, and examples thereof include alumina (aluminum oxide, Al ₂ O ₃ ), aluminum nitride (AlN), and LTCC (Low Temperature Co-fired Ceramics). Of course, the material of the insulating base 23 may be a material other than ceramic, or may be a composite material including a plurality of materials.

(1.2.2. Conductors of the mounting base (excluding the portion involved in the bonding between the mounting base and the cover))

As described above, the mounting base 11 has the four terminals 3 , the two pads 25 , and the wirings 27 .

The four terminals 3 are, for example, composed of a layered (pad-shaped) conductor (e.g., metal) overlapping the second substrate surface 23d of the substrate portion 23a. The position, shape, and size of the terminal 3 are arbitrary. For example, the four terminals 3 are located at the four corners of the second substrate surface 23d. In addition, at this time, when viewed from above, each terminal 3 can be separated from the two mutually intersecting edges (long sides and short sides) of the second substrate surface 23d, or not separated (example shown in the figure). In addition, whether it is located at the four corners can be reasonably judged based on the size of the substrate portion 23a, the size of the terminal 3, the distance between the edge of the substrate portion 23a and the edge of the terminal 3, etc. The same is true for the pads 25 described later.

The positional relationship between the two terminals 3 connected to the crystal element 5 and the two terminals 3 connected to the temperature sensing element 7 is arbitrary. For example, the two terminals 3 of the former may be located on one side (-D1 side) of the long side direction of the substrate portion 23a, and the two terminals 3 of the latter may be located on the other side (+D1 side) of the long side direction of the substrate portion 23a. In addition, for example, the two terminals 3 of the former may be located at a pair of diagonal corners, and the two terminals 3 of the latter may be located at the other pair of diagonal corners.

The two pads 25 are, for example, composed of a layered (pad-shaped) conductor (e.g., metal) overlapping the first substrate surface 23c of the substrate portion 23a. The position, shape, and size of the pads 25 are arbitrary. For example, the two pads 25 are located closer to one end side (-D1 side) of the long side direction of the substrate portion 23a than the center of the substrate portion 23a, and are arranged in the short side direction of the substrate portion 23a. More specifically, the two pads 25 are located at two corners located on one side of the long side direction among the four corners of the bottom surface of the recess R1.

The plurality of wirings 27 may be respectively configured as appropriate structures. For example, each wiring 27 may include any of the following. A via conductor that penetrates the insulating substrate 23 (substrate portion 23a and/or frame portion 23b) in the thickness direction (D3 direction). A layered conductor (layered wiring) that overlaps the surface (upper surface, lower surface and/or side) of the insulating substrate 23 (substrate portion 23a and/or frame portion 23b). A layered conductor that is located inside the insulating substrate 23 (e.g., the boundary between the substrate portion 23a and the frame portion 23b) and along the D1-D2 plane (first substrate surface 23c) (e.g., parallel). In addition, the layered conductor that overlaps the side of the insulating substrate 23 includes a layered conductor that is disposed on the inner surface of the castellated structure (recess).

The wiring 27 connecting the pad 25 and the terminal 3 illustrated in FIG3 is composed only of a via conductor penetrating the substrate portion 23a. In a mode in which both the two terminals 3 connected to the crystal element 5 (two pads 25) are located on one side of the long side direction of the substrate portion 23a, the wiring 27 connecting the pad 25 and the terminal 3 not shown in FIG3 can also be set in the same manner. In addition, regardless of whether the two terminals 3 connected to the crystal element 5 are located at a pair of diagonal corners of the substrate portion 23a, the two wirings 27 connected to the crystal element 5 can also be set in a mode other than that shown in the figure.

In addition, in the connection portion between the via conductor and the conductor layer (including not only the conductor layer constituting the wiring 27, but also the pad 25, the terminal 3, the connection electrode 31, etc.), from the perspective of materials, the upper surface or lower surface of the conductor layer may be joined to the lower end surface or upper end surface of the via conductor, the via conductor may penetrate the conductor layer, or such distinction may not be made. In the following, for convenience, in any method, sometimes the expression based on the capture method in which the via conductor is joined to the upper surface or lower surface of the conductor layer is performed.

The conductor layer (terminal 3, pad 25 and wiring 27) may be composed of a single conductor layer made of a single material or a plurality of conductor layers made of different materials. The material structure of the conductor layer may also be different depending on the region.

The specific structure of the via conductor (wiring 27) can be various structures. For example, the via conductor can be solid (without a cavity inside) (the example shown in the figure) or hollow. In addition, the via conductor can be made of the same material as a whole, or the inside and the outer surface can be made of different materials. In addition, for example, the via conductor can be a straight column, a cone, or have a flange at an appropriate position.

The material of the above-mentioned various conductors (conductor layer, via conductor, terminal 3, pad 25 and wiring 27) can be, for example, metal. Examples of the metal include nickel (Ni), tungsten (W), copper (Cu), aluminum (Al), gold (Au), silver (Ag) or platinum (Pt) or an alloy containing at least one of them as a main component.

(1.2.3. Bonding materials)

The conductive bonding material 29 that bonds the crystal element 5 to the pad 25 is, for example, a conductive adhesive. The conductive adhesive is not specifically shown in the figure, but has an insulating adhesive and a conductive filler (conductive powder) dispersed in the adhesive. The adhesive can be either an organic material (such as a resin, more specifically a thermosetting resin) or an inorganic material. The resin can be, for example, a silicone resin, an epoxy resin, a polyimide resin, or a bismaleimide resin. The material of the conductive filler can be, for example, a metal. The metal can be, for example, aluminum, molybdenum, tungsten, platinum, palladium, silver, titanium, nickel, or iron, or an alloy having one or more of them as the main component.

(1.2.4. Cover)

The shape, size and material of the cover 13 are arbitrary as long as they can block the recess R1. In the example shown in the figure, the cover 13 is a roughly flat member. Its planar shape is roughly the same as the planar shape of the frame 23b, that is, a rectangular shape. In another viewpoint, the outer edge of the cover 13 extends along the frame 23b (for example, in parallel). In a top view, the outer edge of the cover 13, for example, the entirety of the cover 13 is located outside the inner edge of the frame 23b (more specifically, the frame upper surface 23e). In addition, in a top view, a part or all of the outer edge of the cover 13 can be consistent with the outer edge of the frame 23b (the example shown in the figure), can be located inside, or can be located outside. The thickness of the cover 13 (when the thickness is not fixed, for example, the minimum thickness, average thickness or maximum thickness) can be thinner, the same, or thicker than the thickness of the crystal element 5 (or crystal blank 15) (when the thickness is not fixed, for example, the thickness in the region of the excitation electrode 19, the minimum thickness or the maximum thickness).

The material of the cover 13 may be a conductive material (e.g., metal), an insulating material, or a combination of the two. The metal may be, for example, iron, nickel, or cobalt, or an alloy having at least one of them as a main component (e.g., Kovar). In addition, in the description of the embodiments, for convenience, the material of the cover 13 is sometimes expressed as a metal. The insulating material may be an inorganic material (e.g., ceramic) or an organic material (e.g., resin).

(1.2.5. Joining of the mounting base and the cover)

The method for joining the mounting base 11 (frame 23b) and the cover 13 can be various methods as long as the recess R1 can be sealed. In the example shown in the figure, a sealing material 33 (reference numeral 3 in the figure) is sandwiched between the mounting base 11 and the cover 13 to join the two. In more detail, in the example shown in the figure, a method for seam welding is shown. In this method, the sealing material 33, for example, has a first metal layer 35 overlapping with the upper surface of the frame 23b and a second metal layer 37 overlapping with the lower surface of the conductive cover 13. Moreover, in a state where the first metal layer 35 and the second metal layer 37 overlap each other, voltage and pressure are applied to these metal layers (in other words, by heating and pressurizing the metal layers) to weld the two.

In addition, a part or all of the sealing material 33 can also be understood as a part of the mounting base 11 or the cover 13. For example, the first metal layer 35 can also be understood as a part of the mounting base 11. The second metal layer 37 can also be understood as a part of the cover 13. In the description of the embodiment, for convenience, the sealing material 33 is sometimes mainly captured as a member different from the mounting base 11 and the cover 13. However, if there is no special description, the sealing material 33 is sometimes expressed as a part of the mounting base 11 or the cover 13 (or the temperature sensing element 407 described later).

The conductive cover 13 (and/or the sealing material 33 (the first metal layer 35 and/or the second metal layer 37). The same applies to this paragraph below.) is not specifically shown in the figure, but can also be connected to the terminal 3 assigned a reference potential via the wiring 27. The terminal 3 assigned a reference potential can be, for example, one of the two terminals 3 connected to the temperature sensing element 7. The path connecting the cover 13 and the terminal 3 and the path connecting the temperature sensing element 7 and the terminal 3 can be at least partially shared with each other. In addition, the temperature sensing element 7 does not have to use a reference potential. In this case, the conductive cover 13 can be set to an electrically floating state, for example, or a reference potential can be assigned by adding a terminal 3 not shown in the figure for the reference potential.

The materials of the first metal layer 35 and the second metal layer 37 are arbitrary. For example, the material of the second metal layer 37 may be solder, and the first metal layer 35 may be a material that improves the wettability of the second metal layer 37. The specific materials in such a method are also arbitrary. For example, the material of the second metal layer 37 may be silver solder or gold tin. The material of the first metal layer 35 may be, for example, a layer containing tungsten or molybdenum, and nickel plating and gold plating are sequentially performed on the surface. In addition, in the method of using solder as the material of the second metal layer 37, the seam welding here can also be understood as brazing.

The mounting base 11 and the cover 13 may be joined together by various methods other than those described above.

For example, the sealing material 33 is not limited to metal (conductive material in another viewpoint), and may be an insulating material. As such a material, for example, glass can be cited. In other words, glass sealing can also be performed. As specific types of glass, for example, lead-based or lead-free low-melting-point glass can be cited. As lead-free, for example, bismuth-based or tin-based can be cited. The glass transition temperature of the low-melting-point glass is, for example, above 200°C and below 500°C.

In addition, for example, it is also possible to join without melting, unlike welding and brazing. In another viewpoint, the second metal layer 37 may not be a brazing material. For example, the joining of the first metal layer 35 and the second metal layer 37 may also be diffusion bonding (in another embodiment, direct bonding between metals). In more detail, for example, a given treatment (such as grinding and/or activation treatment) may be applied to the overlapping surfaces of the first metal layer 35 and the second metal layer 37, and these metal layers may be pressurized at a temperature below the melting point. Heating may be performed or not, and unlike seam welding, energization is not necessary.

In addition, for example, in the method of seam welding (or other welding), the brazing material (the second metal layer 37 in the above description) may not be used. For example, the metallic cover 13 may be directly welded to the first metal layer 35. Alternatively, the second metal layer 37 may be composed of a material different from the material (brazing material) exemplified above.

In addition, for example, the method of heating the conductive or insulating sealing material 33 may be various methods other than energizing. For example, heating may be performed by placing the resonator 1 in a furnace, by irradiating ultrasonic waves, by irradiating lasers, or by a combination thereof.

The shape and size of the sealing material 33 (the first metal layer 35 and/or the second metal layer 37 in another view. The same applies to this paragraph and the next paragraph unless otherwise specified below) when viewed from above are set to be frame-shaped (ring-shaped) in the overlapping area with the upper surface 23e of the frame in a top-view perspective. For example, the sealing material 33 has a shape and size that is accommodated in the upper surface 23e of the frame in a top-view perspective. In the example shown in the figure, the outer edge of the sealing material 33 (the first metal layer 35 in another view) coincides with the outer edge of the upper surface 23e of the frame. In addition, the outer edge of the sealing material 33 (the second metal layer 37 in another view) coincides with the outer edge of the lower surface 13b of the cover. However, part or all of the outer edge of the sealing material 33 may not coincide with the outer edge of the upper surface 23e of the frame and/or the lower surface 13b of the cover.

As described above, the connection electrode 31 connected to the temperature sensing element 7 is provided on the frame upper surface 23e. Therefore, at least at the configuration position of the connection electrode 31, the sealing material 33 is separated from the inner edge of the frame upper surface 23e. In another viewpoint, for example, at least at the configuration position of the connection electrode 31, the width of the sealing material 33 (the length from the inner edge to the outer edge) is narrower than the width of the frame upper surface 23e. Outside the configuration position of the connection electrode 31, the inner edge of the sealing material 33 can be separated from the inner edge of the frame upper surface 23e (the example shown in the figure) or can be consistent with the inner edge of the frame upper surface 23e. In other words, outside the configuration position of the connection electrode 31, the width of the sealing material 33 can be narrower than the width of the frame upper surface 23e, or can be equal.

When the sealing material 33 is conductive, the sealing material 33 is separated from the two connection electrodes 31 (the example shown in the figure). However, the sealing material 33 may be connected to one of the two connection electrodes 31 on the frame upper surface 23e (see FIG. 9 described later). In this case, one of the two connection electrodes 31 (one of the two external electrodes 7b of the temperature sensing element 7 in another viewpoint) may be given a reference potential, for example. In addition, the insulating sealing material 33 may be in contact with one or both of the two connection electrodes 31.

In a method (refer to FIG. 9 described later) in which a connecting electrode 31 is connected to a conductive sealing material 33 (e.g., a first metal layer 35), the two may be made of different materials or may be formed integrally of the same material. In the latter method, a connecting electrode 31 and a first metal layer 35 may not be distinguished by their thickness and planar shape. For example, the first metal layer 35 may overlap the entire length and width of one side of the upper surface 23e of the frame portion in a top perspective view, and a portion of its area may be used as a connecting electrode 31.

As understood from the description so far, the sealing material 33 can be extended with a fixed width throughout the entire circumference (the example shown in the figure), or it can be extended while changing the width. As the latter method, for example, a method in which the width of each of the four sides of the upper surface 23e of the frame portion is fixed and the widths of the sides are different from each other can be cited. In this case, for example, the width of the sealing material 33 on the side where the connecting electrode 31 is configured can be narrower than the width of the sealing material 33 on the side where the connecting electrode 31 is not configured. In addition, as other methods of extending the sealing material 33 while changing the width, for example, a method in which the width changes on each side can be cited. More specifically, for example, a method in which the width narrows only in the configuration area of the connecting electrode 31 and its surroundings can be cited.

The specific size of the width of the sealing material 33 is arbitrary. For example, relative to the width of the upper surface 23e of the frame portion (the width at the same position as the width of the above-mentioned sealing material 33 in the circumferential direction), the width of the sealing material 33 (for example, the minimum width) can be set to more than 1/10, more than 1/5, more than 1/3 or more than 1/2, and can also be set to less than 4/5, less than 3/4, less than 2/3 or less than 1/2. The above-mentioned lower limit and upper limit can combine any numerical values with each other without causing any contradiction. In addition, with respect to the width of the upper surface 23e of the frame portion, any value of the previously exemplified lower limit and/or upper limit and any value combination of the above-mentioned lower limit and/or upper limit related to the width of the sealing material 33 can also be combined.

The thickness of the sealing material 33 is, for example, fixed throughout its entire circumference. The specific value of the thickness of the sealing material 33 is arbitrary. For example, the thickness of the sealing material 33 can be thinner, the same, or thicker than the thickness (minimum thickness or maximum thickness) of the crystal element 5 (or the crystal blank 15). The thickness of the first metal layer 35 can be, for example, greater than 10 μm and less than 30 μm, and can also be thicker than this range. The thickness of the second metal layer 37 can be, for example, greater than 10 μm and less than 40 μm, and can also be thicker than this range.

(1.3. Temperature sensing element (including the temperature sensing element of the package))

(1.3.1. Overview of the structure of the temperature sensing element)

As described above, in the present embodiment, the temperature sensing element 7 is composed of a film-shaped element. The type of such a film-shaped temperature sensing element 7 (in another viewpoint, the temperature detection principle) is arbitrary. For example, the temperature sensing element 7 may be a thermistor, a temperature measuring resistor, a thermocouple, or a diode. The specific structure of various temperature sensors is also arbitrary. In addition, in the description of the embodiment, for convenience, sometimes it is not specifically described, and the temperature sensing element 7 is expressed as an example of a thermistor.

In addition, the fact that the temperature sensing element 7 is a film-shaped element and not a chip-type temperature sensing element can be reasonably determined based on common technical knowledge. For example, the temperature sensing element 7 is composed of one or more layers overlapping the film-forming object (cover 13), while the chip-type temperature sensing element is mounted with a packaged structure through a bonding material (such as a bump). From another point of view, the absolute thickness of the temperature sensing element 7 or the relative thickness relative to the thickness of the cover 13 does not necessarily need to be extremely thin.

Although not particularly shown in the figure, the following description takes the case where the temperature sensing element 7 is a thermistor as an example, and the specific structure thereof can be in various forms.

Thermistors, for example, have a resistor film whose resistance value changes according to temperature as a basic structural element. The material of the resistor film may be, for example, an oxide (e.g., a composite oxide) or a nitride (e.g., a composite nitride). The oxide or nitride may include one or more of nickel (Ni), manganese (Mn), cobalt (Co), aluminum (Al), iron (Fe) and chromium (Cr). The resistor film may, for example, have only one layer of film composed of a single material, or may have more than two layers of film composed of mutually different materials. In addition, the structure of the material of the resistor film may be the same throughout the entirety when viewed from above, or the structure of the material may be different depending on the region.

The above-mentioned resistive film may overlap with the lower surface 13b of the cover body having conductivity or insulation via an insulating film, or may overlap directly with the lower surface 13b of the cover body having insulation. The insulating film, for example, has a resistivity higher than that of the resistive film. The material of the insulating film is arbitrary, for example, it may be an inorganic material, an organic material, or a combination of the two. Examples of inorganic materials include silicon dioxide ( _SiO2 ) and silicon _nitride ( _Si3N4 ). Examples of organic materials include various resins (for example, epoxy resins or silicone resins). For example, the insulating film may have only one layer of film composed of a single material, or may have two or more layers of film composed of different materials. In addition, the structure of the material of the insulating film may be the same throughout the entire film when viewed from above, or the structure of the material may be different depending on the region.

In addition, the resistor film may be exposed in the space formed by the package 9 (in another viewpoint, the interior of the recess R1), or may be covered by an insulating cover film. The cover film, for example, has a resistivity higher than that of the resistor film. The cover film, for example, may help protect the resistor film or an electrode described later. The material of the cover film is arbitrary. For example, the description of the material of the insulating film in the previous paragraph may be applied to the cover film.

The resistor film can be applied with a voltage through a pair of applied electrodes of appropriate configuration and shape. For example, a pair of applied electrodes can be located at both ends of the long side direction (or short side direction) of the resistor film when viewed from above, and a voltage is applied to the resistor film in the long side direction (or short side direction). In this manner, at least the portion of the pair of applied electrodes connected to the resistor film can overlap with the lower surface (cover body 13 side) of the resistor film, or can overlap with the upper surface of the resistor film. In addition, a pair of applied electrodes can also be opposed in the thickness direction across the resistor film, and a voltage is applied to the resistor film in the thickness direction. The pair of applied electrodes can also be a pair of comb-tooth electrodes that overlap with the upper surface or lower surface of the resistor film and mesh with each other.

In the case where there is a portion of the applying electrode that does not overlap with the upper surface of the resistor film (the surface on the opposite side of the cover body 13), the portion may overlap with the conductive or insulating lower surface 13b of the cover body through the insulating film (or other insulating film) mentioned above, or may directly overlap with the insulating lower surface 13b of the cover body. The same applies to the external electrode 7b and relay conductor described later. The conductive cover body 13 can be used as an applying electrode. In addition, the conductive cover body 13 can be used as a wiring for applying a voltage to the applying electrode by directly overlapping with the applying electrode or indirectly overlapping via other conductive layers. However, in the description of the embodiments, for convenience, it is sometimes presented as if the cover body 13 is not used as an applying electrode or wiring.

The material of the applied electrode is arbitrary. For example, at least a part of the material of the applied electrode may be the same as or different from at least a part of the material of the conductor pattern 17 and the various conductors (3, 25, 27, 31 and 35, etc.) of the mounting substrate 11. In any case, the description of the material of the conductor pattern 17 and the various conductors of the mounting substrate 11 (specific examples of metals, the presence or absence of layers of different materials, the presence or absence of regions of different materials, etc.) mentioned above can be used as the description of the material of the applied electrode. The same applies to the materials of the external electrode 7b and the relay conductor described later.

(1.3.2. Correspondence between the structure of the temperature-sensitive film and the attached figure)

As understood from the above description, the temperature sensing element 7 may have various structures (for example, a resistance film, an insulating film, a cover film, and an application electrode). In FIG. 2 and FIG. 3 (and other drawings), the structure of the temperature sensing element 7 is shown as follows.

In FIG. 2 and FIG. 3 (and other figures), the temperature sensing element 7 includes a temperature sensing film 7a and a pair of external electrodes 7b. A voltage is applied to the temperature sensing film 7a, for example, via the pair of external electrodes 7b. In addition, in another viewpoint, the temperature sensing film 7a outputs a signal of intensity corresponding to the temperature from at least one of the pair of external electrodes 7b.

From the description using the above-mentioned thermistor as an example, it can be understood that the temperature-sensitive film 7a may have only a functional portion that directly contributes to temperature detection (such as a resistance film in a thermistor), or may have an insulating film, a covering film, an applied electrode and/or a relay conductor described in the next paragraph that overlaps with the functional portion.

For example, the external electrode 7b may be a part or all of the applying electrode that directly applies voltage to the resistance film (is in direct contact with the resistance film), or may be an electrode electrically connected to the applying electrode, taking the case where the temperature sensing element 7 is a thermistor as an example. In the latter case, the external electrode 7b may be directly connected to the applying electrode by overlapping with a part of the applying electrode, or may be indirectly connected to the applying electrode via a relay conductor (e.g., a conductor layer different from both the applying electrode and the external electrode 7b).

In addition, from another point of view, the pair of external electrodes 7b can be understood as being shown in their entirety in FIG. 1 and FIG. 2, or as being shown as being partially shown. In the latter case, the aforementioned portion can be, for example, a portion of the pair of external electrodes 7b covered by the covering film that is exposed from the covering film. In addition, the aforementioned portion can also be understood as showing a portion of the pair of external electrodes 7b that is extracted and that contributes to the connection with the package 9 (other portions of the pair of external electrodes 7b are also exposed, but are omitted in the drawings).

To give a specific example, as described above, the temperature sensing element 7 may have a pair of applied electrodes overlapping the functional portion on both sides of a given direction (e.g., the direction in which the functional portion (resistive film) extends) when viewed from above. In this case, the pair of external electrodes 7b illustrated in FIG. 2 may be, for example, a portion (exposed portion or extracted portion) of the pair of applied electrodes, or a pair of terminals directly or indirectly connected to the pair of applied electrodes.

In addition, for example, as described above, the temperature sensing element 7 may have a pair of applying electrodes sandwiching a resistive film in the thickness direction. In this case, the pair of external electrodes 7b illustrated in FIG. 2 may be a part (exposed part or extracted part) of the pair of applying electrodes, or may be a pair of terminals directly or indirectly connected to the pair of applying electrodes. In the former mode, the pair of external electrodes 7b may be an end of one applying electrode when viewed from above and an end of the other applying electrode when viewed from above.

In addition, for example, as described above, the temperature sensing element 7 may have a pair of comb-tooth electrodes as a pair of applied electrodes. The pair of external electrodes 7b illustrated in FIG. 2 may be a portion (exposed portion or extracted portion) of a pair of conductor patterns including a pair of comb-tooth electrodes, or may be a pair of terminals directly or indirectly connected to a pair of comb-tooth electrodes. In more detail, a pair of comb-tooth electrodes may have, for example, a pair of bus bars opposed to each other and a plurality of electrode fingers extending from each bus bar to the other bus bar. A portion of the above-mentioned pair of conductor patterns may be, for example, a portion extending from a pair of bus bars. In addition, the above-mentioned pair of terminals may be, for example, directly or indirectly connected to a pair of bus bars.

In addition, when viewed from above, the relationship between the shape of the temperature sensing element 7 and the arrangement of a pair (or more than two pairs) of comb-tooth electrodes is arbitrary. For example, in the case where at least a portion (the entirety in the example of FIG. 2 ) of the temperature sensing element 7 is a shape having a long side direction and a short side direction (referred to as a first shape in this paragraph), a pair of comb-tooth electrodes may be arranged so that a pair of bus bars extend in the long side direction and a plurality of electrode fingers extend in the short side direction. In the case where the temperature sensing element 7 has a plurality of first shapes, a pair of comb-tooth electrodes may be provided in each first shape.

(1.3.3. Position, shape and size of temperature sensing element)

The position (position in the cover 13. The same shall apply hereinafter unless otherwise specified.), shape and size of the temperature sensing element 7 are arbitrary. In addition, as long as no contradiction occurs, the description of the position, shape and size of the temperature sensing element 7 may also refer to the position, shape and size of the temperature sensing film 7a. As understood from the above-mentioned example of the thermistor, the position, shape and size of the temperature sensing film 7a are the position, shape and size of the functional part in the case where the temperature sensing film 7a is composed only of the functional part (the resistance film in the thermistor), and the position, shape and size of the functional part and other parts as a whole in the case where the temperature sensing film 7a includes other parts (insulating film, covering film, applied electrode and/or relay conductor). However, as long as no contradiction occurs, the description of the position, shape and size of the temperature sensing element 7 may also refer to the position, shape and size of the functional part, or the combination of the functional part and other parts directly above it in the case where the temperature sensing film 7a includes other parts other than the functional part.

It can also be understood from other examples described later that the temperature sensing element 7 can be located in any area of the lower surface 13b of the cover body. For example, when viewed from above, the temperature sensing element 7 can be housed in the recess R1 (in another perspective, the inner side of the upper surface 23e of the frame portion) (examples in Figures 2 and 3), or can be located outside the recess R1 (example in Figure 6 described later), or can span the recess R1 and its outside. In other words, when viewed from above, the temperature sensing element 7 may or may not have a portion that overlaps with the recess R1, and may or may not have a portion that overlaps with the outer side of the recess R1. In addition, in another perspective, the temperature sensing element 7 may or may not be in contact with the sealed space formed by the recess R1.

In addition, in the top perspective, in the manner in which the temperature sensing element 7 and the recess R1 overlap, the temperature sensing element 7 may overlap with the geometric center of the recess R1 or may not overlap. In addition, regardless of whether the temperature sensing element 7 and the recess R1 or the geometric center of the recess R1 overlap, the geometric center of the temperature sensing element 7 may be substantially consistent with or inconsistent with the geometric center of the recess R1. For example, when the distance between the geometric centers is less than 1/5 of the minimum length of the recess R1, it can be understood that the two are consistent.

In the manner in which the temperature sensing element 7 overlaps with the recess R1 in a top view perspective, the width of the overlap is arbitrary. For example, the area in which the temperature sensing element 7 overlaps with the recess R1 may be more than 1/5, more than 1/3, more than 1/2, more than 2/3, more than 4/5, less than 1 time, less than 4/5, less than 2/3, less than 1/2, less than 1/3, or less than 1/5 of the area of the recess R1. The above lower limit and upper limit may be any combination of numerical values without causing any contradiction. Furthermore, the temperature sensing element 7 may overlap with the entire recess R1. In addition, the lower limit and/or upper limit of this paragraph refers to the length (e.g., maximum length) of the temperature sensing element 7 overlapping with the length (e.g., maximum length) of the recess R1 in any direction (e.g., long side direction or short side direction) of the recess R1 in a top view perspective.

The description of the position and width of the temperature sensing element 7 in comparison with the above recess R1 (whether it overlaps with the recess R1, whether the geometric center is consistent, and the overlapping area relative to the area of the recess R1, etc.) can replace the terminology of the recess R1 with the terminology of the crystal element 5 or the terminology of the excitation electrode 19, and refer to the description of the position and width of the temperature sensing element 7 in comparison with the crystal element 5 or the excitation electrode 19.

In the example shown in the figure, the temperature sensing element 7 roughly overlaps with the entirety of the recess R1 in a top-view perspective. That is, in a top-view perspective, the temperature sensing element 7 (more specifically, the temperature sensing film 7a) has the same shape and size as the shape and size of the recess R1. Therefore, the above-mentioned description of the shape and size of the recess R1 in a top view can be applied to the planar shape of the temperature sensing film 7a. In addition, in a top-view perspective, the temperature sensing element 7 overlaps with the entirety of the recess R1, and therefore also overlaps with the entirety of the crystal element 5 and the entirety of the excitation electrode 19. Furthermore, in a top-view perspective, the geometric center of the temperature sensing element 7 is roughly consistent with or relatively close to the geometric center of the recess R1, the geometric center of the crystal element 5, and the geometric center of the excitation electrode 19.

Of course, unlike the example shown in the figure, the shape and size of the temperature sensing element 7 may be different from the shape and size of the recess R1 in a top view. For example, the temperature sensing element 7 may be a rectangular shape smaller than the recess R1 in a top view. In this case, the long side direction of the rectangle may be the same as the long side direction and the short side direction of the recess R1. In addition, the rectangle may be a square. In addition, in a top view, the temperature sensing film 7a may be separated from the upper surface 23e of the frame portion over its entire circumference.

Furthermore, in the top view, the shape of the temperature sensing element 7 may be a shape other than a rectangle, regardless of whether it is the same as the shape of the recess R1. As shapes other than a rectangle, for example, a circle, an ellipse, and a polygon other than a rectangle can be cited. These shapes can be said to be shapes like the boundary line of a convex set in mathematics. In addition, in addition to this, the shape of the temperature sensing element 7 may also be a shape that is separated from the boundary line of a convex set, such as an L-shape or a U-shape.

The temperature sensing element 7 may have a substantially constant thickness throughout the entire region, or may have a plurality of regions with different thicknesses. The upper surface of the temperature sensing element 7 may be, for example, a flat surface, a curved surface, or a concave-convex shape. As a shape with concave-convex shapes, a shape having a plurality of planes with different heights may be cited. As such a shape, for example, a shape in which the presence or absence of a resistance film and/or a relay conductor appears on the upper surface of a cover film covering these may be cited.

The specific thickness of the temperature sensing element 7 is arbitrary. For example, the maximum thickness or average thickness of the temperature sensing element 7 may be 1/300 or more, 1/200 or more, 1/100 or more, 1/50 or more, 1/30 or more, 1/10 or more, 1/5 or more, or 1/2 or more relative to the minimum thickness, average thickness, or maximum thickness of the crystal blank 15, and may also be less than 2 times, less than 1 time, less than 1/5, less than 1/10, or less than 1/100. The above lower limit and upper limit may be combined with any numerical values without causing any contradiction. In addition, the thickness of the temperature sensing element 7 may be, for example, 0.05 μm or more, 0.1 μm or more, 1 μm or more, 5 μm or more, or 10 μm or less, and may also be less than 100 μm, less than 50 μm, or less than 10 μm. The above lower limit and upper limit may be combined with any numerical values without causing any contradiction.

The value of the first distance (e.g., the shortest distance or the average distance) between the temperature sensing element 7 and the crystal element 5 is arbitrary. For example, the first distance may be smaller than the thickness of the crystal element 5 or the distance (e.g., the shortest distance or the average distance) between the crystal element 5 and the bottom surface of the recess R1, or may be equal to or larger than these.

As described above, the crystal element is not limited to a plate shape, and may be a tuning fork type or other various elements. In this case, the temperature sensing element may also be set in position, shape, and size so as to be opposed to a specific portion of the crystal element. For example, in a mode in which the crystal element has a base and an arm for vibration extending from the base, the temperature sensing element may also have a strip shape that is opposed to the arm for vibration and is not opposed to the base.

(1.3.4. Position, shape and size of external electrodes)

The pair of external electrodes 7b is located, for example, in a region overlapping the frame upper surface 23e in a plan view of the cover 13. Thus, when the cover 13 covers the recess R1, the pair of external electrodes 7b and the pair of connection electrodes 31 located on the frame upper surface 23e are opposed and connected.

In a top perspective view, a pair of external electrodes 7b can be located in any area within the frame upper surface 23e. For example, each external electrode 7b can be converged to one side of the four sides of the frame upper surface 23e (the example shown in the figure), or can extend over two or more sides. In addition, in the following description, unless otherwise specified, and unless there is a contradiction, it can be understood that one external electrode 7b converges to one side.

In addition, for example, one external electrode 7b may be located on any one of the long side and the short side of the four sides of the frame upper surface 23e. In addition, two external electrodes 7b may be located on the same side (example in FIG. 2 ) or on two different sides (see FIG. 4A and FIG. 4B described later). The two different sides may be two sides opposite to each other or two sides intersecting each other.

In addition, for example, one external electrode 7b that converges on one side of the frame upper surface 23e may be located in any region in the long side direction of one side. For example, one external electrode 7b may be located on the entire side (refer to FIG. 4B described later) or on a portion of one side (examples in FIG. 2 and FIG. 4A described later). In the latter method, one external electrode 7b may be located on the end side of one side (examples shown in the figure) or on the center side of one side.

When viewed from above, a pair of external electrodes 7b is located, for example, at a position closer to the inside than the sealing material 33 (the second metal layer 37 in another viewpoint). In more detail, for example, a pair of external electrodes 7b is separated from the conductive sealing material 33 (the first metal layer 35 and/or the second metal layer 37 in another viewpoint) (example shown in the figure). However, one of the pair of external electrodes 7b may also be connected to the conductive sealing material 33 at the lower surface 13b of the cover (the upper surface 23e of the frame). In this case, the above-mentioned one external electrode 7b may be assigned a reference potential, for example. In addition, one or both of the pair of external electrodes 7b may be in contact with the insulating sealing material 33 or may not be in contact with it.

In a method where an external electrode 7b is connected to a conductive sealing material 33 (e.g., a second metal layer 37), the two may be made of different materials or may be formed integrally of the same material. In the latter method, an external electrode 7b and a second metal layer 37 may not be distinguished by their thickness and planar shape. For example, the second metal layer 37 may have a width that extends over the entire length and width of one side of the upper surface 23e of the frame portion when viewed from above, and a portion of the area thereof may be used as an external electrode 7b.

In a perspective top view, as long as the pair of external electrodes 7b are located inside the sealing material 33 as described above, they can be located in any area in the width direction (direction from the inner edge to the outer edge) in the frame upper surface 23e. For example, the pair of external electrodes 7b can be located inside the center of the width direction of the frame upper surface 23e, can overlap with the center in the width direction, can overlap with the inner edge of the frame upper surface 23e, and can be away from the inner edge of the frame upper surface 23e to the outside. The external electrode 7b may also have a portion located inside the inner edge of the frame upper surface 23e.

As can be understood from the description of the positions described above, the shape and size of the external electrode 7b when viewed from above are arbitrary. For example, the planar shape of the external electrode 7b may be a rectangular shape located on one side of the frame upper surface 23e (the example shown in the figure), or may be a roughly L-shaped shape along two of the four sides of the frame upper surface 23e, or may be a roughly U-shaped shape along three of the four sides of the frame upper surface 23e. In addition, the shape of the external electrode 7b located on one side is not limited to a rectangular shape, and may be other shapes (for example, a circular shape, an elliptical shape, or a polygonal shape other than a rectangle, etc.).

In addition, for example, the length of one external electrode 7b relative to the length of one side of the inner edge of the frame upper surface 23e can be less than 1/2, or more than 1/2. In addition, for example, the width of the external electrode 7b relative to the width of the frame upper surface 23e can be less than 1/3, or more than 1/3.

As described above, the structure of the temperature-sensitive film 7a can be set to various structures. For example, a relay conductor that electrically connects the applied electrode for applying voltage to the functional part (the resistive film in the thermistor) and the external electrode 7b can be sandwiched. Furthermore, at least two of the applied electrode, the relay conductor and the external electrode 7b can be three-dimensionally crossed via an insulator, or two or more (for example, more than two layers) of relay conductors can be sandwiched between the applied electrode and the external electrode 7b. As understood from this, the position, shape and size of the external electrode 7b can be set to any position, shape and size regardless of the position, shape and size of the temperature-sensitive film 7a (functional part).

For example, each external electrode 7b may be either converging to the configuration area of the temperature-sensitive film 7a (functional portion) or not. The specific position of the external electrode 7b relative to the temperature-sensitive film 7a in the former method is also arbitrary. For example, the external electrode 7b may be located in a region adjacent to the edge of the temperature-sensitive film 7a or in a region away from the edge of the temperature-sensitive film 7a (refer to FIG. 5A described later). In addition, in a method in which the external electrode 7b has a portion located outside the configuration area of the temperature-sensitive film 7a, the external electrode 7b may extend from a position overlapping with the temperature-sensitive film 7a to an arbitrary position, or may be located in an arbitrary region and connected to the temperature-sensitive film 7a via a relay conductor. In addition, in such a method, the temperature-sensitive film 7a may also be located in a region away from the upper surface 23e of the frame portion to the inside in a plan view (for example, a region overlapping with the crystal element 5 or the excitation electrode 19).

In the examples shown in FIGS. 1 to 3 , when viewed from above, the two external electrodes 7b are located on the side opposite to the side where the two pads 25 are located (+D1 side) relative to the center of the package 9 in the long side direction of the package 9. More specifically, the two external electrodes 7b are arranged together with the short side on the +D1 side of the four sides of the frame upper surface 23e. In addition, the two external electrodes 7b are arranged separately from each other on both sides of the short side on the +D1 side in the direction in which the short side extends. In addition, the two external electrodes 7b overlap the inner edge of the frame upper surface 23e.

The thickness of the external electrode 7b is arbitrary. However, in the examples of Figures 1 to 3, the connecting electrode 31 and the external electrode 7b are bonded to each other between the planar lower surface 13b of the cover and the planar upper surface 23e of the frame, so the thickness of the external electrode 7b is smaller than the thickness of the sealing material 33. In addition, on the upper surface 23e of the frame, by making the configuration area of the connecting electrode 31 lower than the configuration area of the first metal layer 35, the thickness of the external electrode 7b can also be made greater than the thickness of the sealing material 33. The thickness of the external electrode 7b can be thinner than the thickness of the second metal layer 37, can be equal to it, or can be thicker than it. In addition, the description of the thickness of the external electrode 7b in this paragraph can be referred to the thickness of the connecting electrode 31. At this time, the terminology of the second metal layer 37 can be replaced by the terminology of the first metal layer 35.

(1.3.5. Parts related to the temperature sensing element of the package)

As described above, the package 9 (mounting base 11) has a connection electrode 31 connected to two external electrodes 7b. The connection electrode 31 and the external electrode 7b are joined to each other in a mutually opposed manner. In a top view, the connection electrode 31 and the external electrode 7b may be substantially consistent, or may be staggered while overlapping. In any case, the descriptions of the position, shape, and size of the external electrode 7b in the top view may be applied to the position, shape, and size of the connection electrode 31 in the top view as long as no contradiction is caused.

The two connection electrodes 31 are electrically connected to the two terminals 3 via two wirings 27. It has been described that the wirings 27 can be set to various structures. The wirings 27 connecting the connection electrodes 31 and the terminals 3 illustrated in FIG. 3 are composed only of via conductors that penetrate the frame portion 23b and the substrate portion 23a. In the manner in which both the two terminals 3 connected to the two connection electrodes 31 are located on one side of the long side direction of the substrate portion 23a, the wirings 27 connecting the connection electrodes 31 and the terminals 3 not shown in FIG. 3 can also be the same. In addition, regardless of whether the two terminals 3 connected to the two connection electrodes 31 are located at a pair of diagonal corners of the substrate portion 23a, the two wirings 27 connected to the two connection electrodes 31 can be in a manner other than that shown in the figure.

The material of the connection electrode 31 is also arbitrary. For example, the material of the connection electrode 31 can be the same as the material of the various conductors (3, 25 and/or 27) of the package 9, or the same as the material of the sealing material 33 (for example, the first metal layer 35). In any case, the description of the material of the various conductors of the package 9 and/or the material of the sealing material 33 can be referred to the material of the connection electrode 31.

The external electrode 7b and the connecting electrode 31 may be joined by various methods. For example, the two may be joined by a conductive joining material (not shown) sandwiched therebetween. The conductive joining material may be either a conductive adhesive or a metal material. The metal material may be either solder (including lead-free solder. The same applies hereinafter) or brazing material. In addition, the external electrode 7b and the connecting electrode 31 may be joined by direct metal-to-metal bonding. The joining method of the connecting electrode 31 and the external electrode 7b may be the same as or different from the joining method of the first metal layer 35 and the second metal layer 37.

The bonding of the external electrode 7b and the connection electrode 31 can be performed, for example, before the sealing process of bonding the mounting base 11 and the cover 13 by the sealing material 33. In the sealing process, the temperature of the external electrode 7b and the connection electrode 31 (and the bonding material in the case where the bonding material is interposed) is set, for example, to be lower than the heat resistance temperature of the conductive adhesive bonding the two, or lower than the melting temperature of the metal material (solder or brazing material, or the external electrode 7b itself and/or the connection electrode 31 itself, the same in the next paragraph) connecting the two. However, the metal material may also be melted and bonded again.

Different from the above, the bonding of the external electrode 7b and the connecting electrode 31 can also be performed simultaneously with the sealing process of bonding the mounting base 11 and the cover body 13 by the sealing material 33. For example, the conductive adhesive between the external electrode 7b and the connecting electrode 31 can be cured by the heat during the sealing process, or the metal material between the external electrode 7b and the connecting electrode 31 (the material that is not bonded to at least one of the external electrode 7b and the connecting electrode 31) can be melted. In addition, it is clarified that the external electrode 7b formed integrally with the second metal layer 37 by the same material as the material of the second metal layer 37 can be bonded to the connecting electrode 31 in the sealing process.

In addition, after the sealing process, the external electrode 7b and the connecting electrode 31 can also be joined. For example, in the sealing process, the temperature of the external electrode 7b and the connecting electrode 31 is set to be, for example, lower than the melting temperature of the metal material connecting the two. After that, the external electrode 7b and the connecting electrode 31 can be heated by irradiation of ultrasonic waves, etc., or the cover 13 can be locally pressurized by an appropriate tool.

(1.4. Other Examples of the First Embodiment)

(1.4.1. Other examples involving external electrodes)

4A and 4B are plan views showing the lower surface 13 b of the cover body where the temperature sensing element 7A or 7B according to other examples is located.

As described above, the position, shape and size of the external electrode 7b (connecting electrode 31 in another viewpoint) can be various. FIG. 4A and FIG. 4B are diagrams showing examples of the position, shape and size of the external electrode 7b different from those shown in FIG. 1 to FIG. 3. Specifically, as described below. In addition, although not specifically shown in the figure, the position, shape and size of the connecting electrode 31 connected to the external electrode 7b involved in other examples are roughly the same as the position, shape and size of the external electrode 7b involved in other examples.

In the example shown in FIG. 4A , the two external electrodes 7b are adjacent to two different edges (sides) of the rectangular (in other words, a shape that can conceptualize four edges) temperature-sensitive film 7a. In another viewpoint, when viewed from above, the two external electrodes 7b overlap on two different sides of the rectangular (in other words, a shape that can conceptualize four sections (sides)) frame upper surface 23e. In more detail, the two external electrodes 7b are located on two short sides of the temperature-sensitive film 7a or the frame upper surface 23e. In addition, the two external electrodes 7b are located on the opposite sides of each other in the direction (D2 direction) in which the short sides extend.

In the example shown in FIG. 4B , similarly to the example shown in FIG. 4A , the two external electrodes 7 b are located at two different sides (more specifically, two short sides) of the temperature sensitive film 7 a (the frame upper surface 23 e in another viewpoint). However, each external electrode 7 b covers most (e.g., more than 80%, and in the example shown in the figure, the entire) of the length of each side (the length based on the inner circumference of the frame upper surface 23 e).

(1.4.2. Other examples related to temperature sensitive film)

5A, 5B, and 5C are cross-sectional views showing a portion of crystal resonators 1C, 1D, and 1E according to other examples. These drawings correspond to the upper portion of FIG. 3 .

As described above, the position, shape, and size of the temperature sensitive film 7a can be various. Fig. 5A to Fig. 5C are diagrams showing examples of positions, shapes, and sizes different from those shown in Fig. 1 to Fig. 3. Specifically, they are as follows.

In addition, in FIG. 5A to FIG. 5C, regarding the positions of the two external electrodes 7b, the two external electrodes 7b are located on the edge of the +D1 side of the frame upper surface 23e as in the embodiment. However, as understood from the description so far, the positions of the two external electrodes 7b are arbitrary, for example, the positions illustrated in FIG. 4A and FIG. 4B or positions similar thereto may be used.

In the example shown in FIG5A , the temperature-sensitive film 7a of the temperature-sensitive element 7C has a portion located outside the recess R1 in a plan view. More specifically, the temperature-sensitive film 7a overlaps the entire surface of the lower surface 13b of the cover. Accordingly, the sealing material 33C of the package 9C is bonded to the lower surface 13b of the cover via the temperature-sensitive film 7a.

In the mode where the temperature-sensitive film 7a has a portion located outside the recess R1 (including the examples of FIG. 5B and FIG. 6 described later), the width of the portion is arbitrary. For example, in a top perspective view, the area of the portion located outside the recess R1 (and/or the portion overlapping with the frame upper surface 23e) can be 1/5 or more, 1/3 or more, 1/2 or more, 2/3 or more, 4/5 or more, or 1 times the area of the frame upper surface 23e. In the above description, the term "area" can also be replaced by the term "length" in the width direction of the frame upper surface 23e.

In the description of the previous paragraph, the term "recess R1" may be replaced by the term "crystal element 5". In this case, the term "frame upper surface 23e" may be replaced by the term "region from the outer edge of the crystal element 5 to the inner edge or the outer edge of the frame upper surface 23e". Furthermore, in the description of the previous paragraph, the term "recess R1" may be replaced by the term "excitation electrode 19". In this case, the term "frame upper surface 23e" may be replaced by the term "region from the outer edge of the excitation electrode 19 to the outer edge of the crystal element 5" or the term "region from the outer edge of the excitation electrode 19 to the inner edge or the outer edge of the frame upper surface 23e".

In addition, the sealing material 33C can be either a conductive material (e.g., metal) or an insulating material (e.g., glass). In the former embodiment, the temperature-sensitive film 7a can have an insulating covering film between the functional portion (a resistive film in the thermistor) and the sealing material 33C. In the latter embodiment, the temperature-sensitive film 7a can have a covering film or not. In FIG. 5A , the sealing material 33C is shown as a single-layer material. However, the sealing material 33C can also include a first metal layer 35 and a second metal layer 37 as in the embodiment.

In the example shown in FIG. 5B , the temperature-sensitive film 7a of the temperature-sensitive element 7D has a portion located outside the recess R1 when viewed from above, similarly to the example shown in FIG. 5A . However, in the temperature-sensitive element 7D, the temperature-sensitive film 7a does not overlap with the entire surface of the lower surface 13b of the cover body, but overlaps with a portion of the lower surface 13b of the cover body. In more detail, the outer edge (for example, the entirety) of the temperature-sensitive film 7a is located inside the outer edge of the lower surface 13b of the cover body (in another viewpoint, the upper surface 23e of the frame). In addition, in the package 9D shown in FIG. 5B , the bonding of the mounting base 11D and the cover body 13 may be performed at the periphery of the temperature-sensitive film 7a (temperature-sensitive element 7D) similarly to the embodiment (the example shown in the figure), or may be performed via the temperature-sensitive film 7a similarly to the example of FIG. 5A .

The temperature sensing element 7D shown in FIG5B is also an example of a method in which the thickness of the temperature sensing film 7a is thicker than the thickness of the sealing material 33. In such a method, the arrangement area of the connection electrode 31 on the frame upper surface 23e can be lower than the arrangement area of the sealing material 33 (it can also be located on the bottom surface side of the recess R1). This reduces the possibility that the sealing performance of the recess R1 is reduced due to the thickness of the temperature sensing film 7a.

In addition, various methods can be used to make the configuration area of the connection electrode 31 lower than the configuration area of the sealing material 33 on the frame upper surface 23e. For example, similar to the formation of the recess R1, the area can be relatively raised by stacking ceramic green sheets in the configuration area of the sealing material 33, or the configuration area of the connection electrode 31 can be relatively lowered by punching. In addition, the configuration area of the connection electrode 31 can also be made relatively lower by grinding, grinding, cutting or laser processing.

In the example shown in FIG. 5C , the temperature-sensitive film 7a of the temperature-sensitive element 7E is similar to the embodiment, and when viewed from above, it roughly overlaps with the entirety of the recess R1. However, the temperature-sensitive film 7a is housed in a recess provided on the lower surface 13b of the cover (the reference numerals are omitted). The thickness of the temperature-sensitive film 7a can be smaller or equal to the depth of the recess provided on the lower surface 13b of the cover (the example shown in the figure), or it can be thicker. In addition, this example can be applied not only to a temperature-sensitive film 7a having a width that extends over the entirety of the recess R1, but also to temperature-sensitive films 7a of various widths that are located as a whole on the inner peripheral side of the outer edge of the cover 13.

In the package 9E, the cover 13E and the mounting base 11 can be joined in the same manner as in the embodiment or other examples. However, by accommodating the temperature-sensitive film 7a in the recess of the cover 13E, the surface of the temperature-sensitive film 7a on the -D3 side is located on the +D3 side compared to the embodiment. As a result, for example, as in the example of FIG. 5B , the possibility that the arrangement area of the connection electrode 31 on the upper surface 23e of the frame portion is lower than the arrangement area of the sealing material 33 is reduced.

FIG. 6 is a perspective view showing a temperature sensing element 7F according to another example.

As described above, the planar shape of the temperature-sensitive film 7a can be various shapes, and is not limited to a rectangular shape or the like. In the temperature-sensing element 7F, the planar shape of the temperature-sensitive film 7a is frame-shaped (annular). In other words, the temperature-sensitive film 7a is a shape that extends along one or more edges of the cover body 13 (in another viewpoint, one or more sides of the upper surface 23e of the frame) (for example, in parallel). The shape extending along the edge does not necessarily have to be annular. For example, the temperature-sensitive film 7a can be along only one side of the rectangular cover body 13, or along only two sides (it can also be L-shaped), or along only three sides (it can also be U-shaped), or it can be interrupted in the middle of the four sides (it can also be C-shaped).

The temperature-sensitive film 7a of the temperature-sensitive element 7F can also be understood as having one or more segments (with reference numerals omitted) extending along one or more edges of the cover body 13. Each segment is roughly rectangular. In another viewpoint, each segment extends with a certain width. In addition, each segment extends over roughly the entirety of an edge (for example, more than 80% of the length). Of course, it can be understood from the description so far that in each segment, the planar shape can be a shape other than a rectangle, the width can vary, and the length can be shorter than the length of an edge. The shapes and sizes of multiple segments can be the same as or different from each other.

The temperature-sensitive film 7a extending along one or more edges of the cover body 13 may or may not overlap with the recess R1 in a plan view. In the example of FIG. 6 , it is assumed that the temperature-sensitive film 7a does not overlap with the recess R1 (or the overlapping area is relatively small). For example, the inner edge of the temperature-sensitive film 7a is substantially consistent with the edge of the recess R1 in a plan view. In addition, the temperature-sensitive film 7a of FIG. 6 is an example of a method in which a portion is located outside the recess R1 in a plan view, similar to the examples of FIG. 5A and FIG. 5B .

When the temperature-sensitive film 7a of the shape along the edge of the cover 13 is viewed from above, the width of the area of the recess R1 that does not overlap with the temperature-sensitive film 7a (the area surrounded by the temperature-sensitive film 7a), the width of the area of the temperature-sensitive film 7a that overlaps with the recess R1, and the width of the area of the temperature-sensitive film 7a that does not overlap with the recess R1 (the area outside the recess R1) are arbitrary. For example, when viewed from above, the area of the area outside the recess R1 of the temperature-sensitive film 7a can be more than 1/2, more than 2/3, more than 4/5, or 1 times the area of the entire temperature-sensitive film 7a. In this description, the term "area" can also be replaced with the term "width" of the temperature-sensitive film 7a (section). In addition, for example, when viewed from above, the area of the area of the recess R1 surrounded by the temperature-sensitive film 7a can be more than 1/2, more than 2/3, more than 4/5, or 1 times the area of the entire recess R1. In this description, the term "area" may be replaced by the term "length" (e.g., maximum length) of the recess R1 in any direction (e.g., long side direction or short side direction) when viewed from above. In the description of this paragraph, the term "recess R1" may be replaced by the term "crystal element 5" or the term "excitation electrode 19".

As described above, the structure of the temperature-sensitive film 7a (such as the shape of the applied electrode, etc.) can be set to various structures. This is also the case in the temperature-sensitive element 7F. For example, the temperature-sensitive element 7 can apply voltages at both ends of the direction in which one or more segments (sides) included in the temperature-sensitive film 7a extend, or can apply voltages in the thickness direction of the temperature-sensitive film 7a, or can apply voltages through one or more comb-tooth electrodes. In the manner of setting the comb-tooth electrodes, for example, a pair of comb-tooth electrodes can be set in each segment. In this case, for example, a pair of comb-tooth electrodes can be arranged in a direction in which a pair of bus bars extend in the long side direction of the segment.

As described above, the positions, shapes and sizes of the two external electrodes 7b can be arbitrary as long as they have a portion overlapping with the upper surface 23e of the frame portion in a top perspective view. In the example of FIG6 , the two external electrodes 7b are located at a pair of diagonal corners of the rectangular frame-shaped temperature-sensitive film 7a. In addition, its shape is a square having the same length as the width of the segment (side) of the temperature-sensitive film 7a. Of course, the two external electrodes 7b can be located in an area other than a pair of diagonal corners (for example, refer to FIG2 or FIG4B ), or can be a shape other than a square (for example, a rectangular or circular shape other than a square).

When viewed from above, the temperature-sensitive film 7a extending along one or more edges of the cover 13 may overlap with the sealing material 33 as in the example of FIG. 5A, or may not overlap with the sealing material 33 as in the example of FIG. 5B. FIG. 6 illustrates the former. In addition, for convenience, the second metal layer 37 is shown here. As can be understood from the description so far, the sealing material 33 may be an insulating material (e.g., glass), or may be located only on the mounting base 11 before the cover 13 and the mounting base 11 are joined.

(1.5. Summary of the First Implementation Method)

As described above, the piezoelectric device (crystal resonator 1) includes a piezoelectric element (crystal element 5), a mounting base 11, and a temperature sensing element 7. The mounting base 11 includes a recess R1 that is sealed airtightly. The crystal element 5 is mounted on the bottom surface of the recess R1. The temperature sensing element 7 includes a portion located on the upper end side (cover 13 side) of the recess R1 relative to the crystal element 5.

Therefore, for example, as described above, the possibility that the temperature sensing element 7 is excessively affected by the heat from the bottom surface side of the recess R1 is reduced. As a result, it is expected that the measured temperature follows the temperature of the crystal element 5 .

The piezoelectric device (crystal resonator 1 ) may include a cover 13 that closes the recess R1 .

In this case, for example, compared with the method in which the temperature sensing element 407 also serves as a cover as in the fourth embodiment described later, a structure similar to or the same as a conventional cover can be used as the structure of the cover 13. As a result, for example, it is easy to ensure the strength of the package 9. In addition, the conventional knowledge about the temperature difference between the outside and the inside of the package 9 can be utilized.

The temperature sensing element 7 may include a temperature sensing film 7 a overlapping the first surface (the cover lower surface 13 b ) of the cover 13 on the side of the mounting base 11 .

In this case, for example, the temperature sensing element 7 is fixed to the cover 13, so after the crystal element 5 is mounted on the mounting base 11 and before the temperature sensing element 7 (via the cover 13) is fixed to the mounting base 11, the crystal element 5 can be inspected through the mounting base 11, or the excitation electrode 19 can be cut by laser to adjust the frequency characteristics. Therefore, for example, even if the crystal element 5 and the mounting base 11 are determined to be defective by the above inspection, the temperature sensing element 7 will not be wasted. In addition, for example, the temperature sensing element 7 will not be cut by the laser. If the temperature sensing element 7 is different from the cover 13, after the frequency adjustment is performed by laser or the like, the frequency characteristics may change when the temperature sensing element 7 is fixed to the mounting base 11 and when the cover 13 is fixed to the mounting base 11, and the change in the frequency characteristics may become larger. However, since both are fixed, it is expected that the change in the frequency characteristics will be reduced. By making the frequency adjustment easy as described above, for example, productivity is improved. Furthermore, since the temperature sensing element 7 has a structure including the temperature sensing film 7a, it is easier to reduce the thickness of the resonator 1 compared with a method in which the temperature sensing element 7 is a chip type (such a method is also included in the technology involved in the present disclosure). In addition, in the process of bonding the cover 13 to the mounting base 11, the possibility of unintentional contact between the mounting base 11 and the side of the temperature sensing element 7 is reduced. In the method of providing a reference potential to the cover 13 and the temperature sensing element 7, since the temperature sensing element 7 is provided on the cover 13, it is easier to share the terminal 3 and the wiring 27 for providing the reference potential to both.

The temperature-sensitive film 7a may have a portion that overlaps with the recess R1 (or the crystal element 5 or the excitation electrode 19) in a plan view. For example, the temperature-sensitive film 7a may overlap with more than 1/3, more than 1/2, or all of the area of the recess R1 (or the crystal element 5 or the excitation electrode 19) in a plan view (see FIGS. 1 to 5C ).

In this case, for example, in a manner in which the temperature-sensitive film 7a can detect the temperature of the crystal element 5 via the gas in the recess R1, the measured temperature easily follows the temperature of the crystal element 5. In addition, for example, since the need to ensure the area of the temperature-sensitive film 7a on the frame upper surface 23e is reduced, it is easy to avoid interference between the structure (for example, the sealing material 33) for sealing the recess R1 and the structure of the temperature-sensitive film 7a. As a result, for example, the structure of the temperature-sensitive film 7a is simplified.

The temperature-sensitive film 7a may have a portion located outside the recess R1 (or the crystal element 5 or the excitation electrode 19) in a plan view. For example, the temperature-sensitive film 7a may overlap with more than 1/5, more than 1/3, more than 1/2, or all of the area of the frame upper surface 23e in a plan view (see FIGS. 5A, 5B, and 6).

In this case, for example, in a method in which the temperature-sensitive film 7a extends from the area overlapping with the recess R1 to the outside thereof as shown in FIGS. 5A and 5B , it is easy to ensure the area of the temperature-sensitive film 7a. As a result, for example, it is advantageous to miniaturize the resonator 1 when viewed from above. In addition, for example, in a method in which the temperature-sensitive film 7a does not overlap with the recess R1 (or the crystal element 5 or the excitation electrode 19) as shown in FIG. 6 , for example, it is possible to avoid contact between the temperature-sensitive film 7a and the crystal element 5. From another point of view, it is advantageous to reduce the thickness of the resonator 1. In addition, in a method in which the space between the crystal element 5 and the temperature-sensitive film 7a has high thermal insulation such as a vacuum in the recess R1, the temperature of the crystal element 5 and the temperature of the temperature-sensitive film 7a are easily equalized via the frame 23b. Furthermore, the measured temperature easily follows the temperature of the crystal element 5.

<2. Second Embodiment>

Fig. 7 is a cross-sectional view showing a crystal resonator 201 according to the second embodiment. This figure corresponds to Fig. 3 of the first embodiment.

In the first embodiment, the temperature sensing element 7 is a film-shaped element, whereas in the second embodiment, the temperature sensing element 207 is a chip-shaped element. Furthermore, the temperature sensing element 207 is mounted on the cover 13 via a conductive bonding material 41. In this manner, as in the first embodiment, the temperature sensing element 207 is located on the cover 13 side relative to the crystal element 5. Therefore, the same effects as in the first embodiment are achieved. For example, the influence of heat from the circuit substrate 53 on which the resonator 1 is mounted on the temperature sensing element 207 is reduced. Specifically, for example, as described below.

The specific structure of the temperature sensing element 207 is arbitrary. For example, the temperature sensing element 207, like the temperature sensing element 7, may be an element of various principles such as a thermistor, a temperature measuring resistor, a thermocouple, or a diode. In addition, for example, the functional part of the temperature sensing element 207 (for example, a resistor in a thermistor) may be exposed to the outside (the space in the recess R1) or covered by a sealing part. The material of the sealing part is arbitrary, for example, it may be an insulating material such as glass, ceramic, or resin.

In the example shown in the figure, the temperature sensing element 207 has an element body 207a and two element terminals 207b (only one is shown in the figure). As understood from the previous paragraph, the element body 207a includes, for example, at least a functional portion, and further, may also have a sealing portion covering the functional portion. The shape of the element body 207a can be, for example, a roughly thin rectangular parallelepiped (more specifically, a plate shape in the example shown in the figure). The two element terminals 207b are, for example, located on the surface of the cover 13 side (+D3 side) of the element body 207a. At this time, the element terminal 207b can be, for example, a layered conductor overlapping the surface on the +D3 side of the element body 207a, or a conductor having at least a portion exposed on the surface on the +D3 side of the element body 207a (not necessarily limited to a layered conductor).

As for the position, shape and size of the element body 207a (temperature sensing element 7) in a plan view, the description of the position, shape and size of the temperature sensing film 7a housed in the recess R1 in a plan view can be used as long as there is no contradiction. For example, the element body 207a may overlap with the entire recess R1 (or the crystal element 5 or the excitation electrode 19) or may overlap with a part of it. The geometric center of the element body 207a may coincide with or not coincide with the geometric center of the recess R1 (or the crystal element 5 or the excitation electrode 19).

The thickness of the element body 207a and the position in the thickness direction (D3 direction) are arbitrary. For example, the thickness of the element body 207a can be thinner, the same, or thicker than the thickness of the crystal element 5 (or the crystal blank 15). In addition, the distance between the element body 207a and the crystal element 5 and the distance between the element body 207a and the lid 13 can be shorter, the same, or longer than the distance between the crystal element 5 and the bottom surface of the recess R1 (the first substrate surface 23c).

The position, shape and size of the component terminal 207b can be arbitrary as long as the component terminal 207b can be joined to the lower surface 13b of the cover body (more specifically, the area opposite to the recess R1) through the bonding material 41. For example, a general chip-type temperature sensing element has two component terminals at both ends in the long side direction. The component terminal at each end overlaps only with the lower surface (here, the surface on the +D3 side) or overlaps with the entirety of each end (five surfaces except the other end sides). The component terminal 207b can also be such a structure.

In the example shown in the figure, the two component terminals 207b are adjacent to the edge (the short side of the edge extending in the D2 direction) of one side (+D1 side) of the long side direction (which can also be set as the short side direction) of the component body 207a, and are arranged along the edge (for example, in parallel). Moreover, the component body 207a is supported in a cantilever beam shape by bonding the two component terminals 207b to the lower surface 13b of the cover body through two bonding materials 41 (only one is shown). In the example shown in the figure, the component terminal 207b has only a first part overlapping with the surface of the cover body 13 side (+D3 side) of the component body 207a. In addition to the above-mentioned first part, the component terminal 207b may also have a part overlapping with the surface of other surfaces (+D1 side, +D2 side, -D2 side and/or -D3 side).

The positions of the two component terminals 207b relative to the mounting base 11 are arbitrary. For example, the two component terminals 207b may be located at the ends of the recess R1 in a given direction (e.g., the long side direction or the short side direction) in a top view, or may be located at a position relatively far from the ends (e.g., the center of the given direction). In the former case, the two component terminals 207b may be located at any two of the four corners, or may be located at a position far from the four corners.

In the example shown in the figure, the two element terminals 207b are located on the opposite side (+D1 side) of the side where the extraction electrode 21 (pad 25) is located with respect to the geometric center of the recess R1 in a plan view, and more specifically, are located at two corners on the +D1 side of the recess R1. Of course, unlike the example shown in the figure, the two element terminals 207b may be located on the side (-D1 side) where the extraction electrode 21 (pad 25) is located with respect to the geometric center of the recess R1 in a plan view, and may also be located at two corners on the -D1 side of the recess R1.

The package 209 is configured to be able to mount the temperature sensing element 207 on the lower surface 13b of the cover. The specific structure thereof is arbitrary. In the illustrated example, at least the lower surface 13b of the cover 13 (e.g., the entire cover 13) is formed of an insulating material. Moreover, the conductor pattern 39 overlaps with the lower surface 13b of the cover. The conductor pattern 39 is not particularly marked with a reference numeral, and for example, may have a first portion joined to the bonding material 41, a second portion joined to the connecting electrode 31, and a wiring portion connecting the two. The specific shape, size, and material of the conductor pattern 39 are arbitrary.

The material of the bonding material 41 is arbitrary. For example, the material of the bonding material 41 may be the same material as the bonding material 29 or a different material. In addition, the bonding material 41 may be a conductive adhesive or solder. Regarding the bonding between the conductor pattern 39 and the connection electrode 31, the description of the bonding between the external electrode 7b and the connection electrode 31 can be referred to.

In Fig. 7, the reference numeral of the sealing material 33C shown in Fig. 5A is shown as a sealing material for bonding the cover 13 to the mounting base 11. However, the sealing material may be any of a conductive material and an insulating material, and may have a material on the mounting base 11 side and a material on the cover 13 side (for example, the first metal layer 35u and the second metal layer 37).

As described above, the piezoelectric device (crystal resonator 201) includes a piezoelectric element (crystal element 5), a mounting base 11, and a temperature sensing element 207. The temperature sensing element 207 has a portion (in the illustrated example, the entire temperature sensing element 207) located on the upper end side (cover body 13 side) of the recess R1 relative to the crystal element 5. Therefore, for example, as described above, the possibility that the temperature sensing element 207 is excessively affected by the heat from the bottom surface side of the recess R1 is reduced. As a result, it can be expected that the measured temperature follows the temperature of the crystal element 5.

Alternatively, the temperature sensing element 207 may be a chip-type element mounted on the surface of the cover 13 on the mounting base 11 side (the cover lower surface 13 b ).

In this case, for example, the temperature sensing element 207 that has already been circulated can be used for the resonator 201. In addition, for example, in the same manner as the film-shaped temperature sensing element 7 is held on the cover 13, when the crystal element 5 and the mounting base 11 are judged as defective by inspection after the crystal element 5 is mounted on the mounting base 11 and before the cover 13 is joined to the mounting base 11, the cover 13 and the temperature sensing element 207 are not wasted.

<3. Third Embodiment>

Fig. 8 is a cross-sectional view showing a crystal resonator 301 according to the third embodiment. This figure corresponds to Fig. 7 of the second embodiment.

In the third embodiment, similarly to the second embodiment, the chip-type temperature sensing element 207 is located on the cover 13 side relative to the crystal element 5. However, in the second embodiment, the temperature sensing element 207 is mounted on the cover 13, whereas in the third embodiment, the temperature sensing element 207 is mounted on the wall portion (frame portion 23b) of the recess R1. Specifically, for example, as described below.

In the package 309 of the third embodiment, the mounting base 311 has a step portion on the wall of the recess R1. In other words, the frame 23b has a surface (with reference numerals omitted) facing the cover 13 at a position lower than the upper surface of the cover 13. The connection electrode 31 is located on this surface. Moreover, the temperature sensing element 207 is mounted on the wall of the recess R1 by bonding the element terminal 207b to the connection electrode 31 through the bonding material 41.

In addition, the frame portion 23b can also be understood as having a first frame portion 23ba overlapping with the substrate portion 23a and a second frame portion 23bb overlapping with the first frame portion 23ba. The width of the second frame portion 23bb is reduced on the inner edge side relative to the first frame portion 23ba in at least a portion of the circumferential direction. As understood from the description of the substrate portion 23a and the frame portion 23b in the first embodiment, the first frame portion 23ba and the second frame portion 23bb can be manufactured by overlapping each other, or by a manufacturing method different from that manufacturing method (e.g., stamping).

As for the position, shape and size of the element body 207a (temperature sensing element 7) in a plan view, the description of the position, shape and size of the temperature sensing film 7a housed in the recess R1 in a plan view can be used as in the second embodiment, as long as there is no contradiction, etc. As for the thickness of the element body 207a and the position in the thickness direction (D3 direction), the description in the second embodiment can be used.

Regarding the position, shape and size of the element terminal 207b when viewed from above, for example, the description of the position, shape and size of the external electrode 7b when viewed from above in the first embodiment can be cited. However, in this reference, for example, in a perspective view from above, it can be understood that the position of the inner edge of the upper surface of the first frame portion 23ba is equivalent to the position of the inner edge of the frame portion upper surface 23e in the description of the first embodiment.

As described above, the piezoelectric device (crystal resonator 301) includes a piezoelectric element (crystal element 5), a mounting base 311, and a temperature sensing element 207. The temperature sensing element 207 has a portion (in the illustrated example, the entire temperature sensing element 207) located on the upper end side (cover body 13 side) of the recess R1 relative to the crystal element 5. Therefore, for example, as described above, the possibility that the temperature sensing element 207 is excessively affected by the heat from the bottom surface side of the recess R1 is reduced. As a result, it can be expected that the measured temperature follows the temperature of the crystal element 5.

In addition, the temperature sensing element 207 may be a chip-type element mounted on the wall portion (frame portion 23 b ) of the recessed portion R1 .

In this case, for example, similarly to the second embodiment, the temperature sensing element 207 that has already been circulated can be used for the resonator 201. In addition, the structure of the cover 13 can be made the same as that of the related art.

<4. Fourth Embodiment>

(4.1. Crystal resonator)

Fig. 9 is an exploded perspective view showing the structure of a crystal resonator 401 according to the fourth embodiment. Fig. 10 is an exploded perspective view of the crystal resonator 401 as viewed from the opposite side to Fig. 9. Fig. 11 is a cross-sectional view taken along line XI-XI of Fig. 9 .

In the fourth embodiment, the cover is composed of a chip-type temperature sensing element 407. In other words, the temperature sensing element 407 is not held in a package 409 (reference numeral 11 ), but constitutes a part of the package 409. In other words, the package 409 has a mounting base 11Z and the temperature sensing element 407 (cover).

The mounting base 11Z can be basically the same as the mounting base 11 of the first embodiment (and other examples involved in the first embodiment, the same). In addition, on the contrary, the various mounting bases involved in the fourth embodiment and other examples described below can be applied to the first embodiment (the cover 13 and the temperature sensing element 7 are different). However, the specific dimensions, etc., of the mounting base of the first embodiment and the mounting base of the fourth embodiment may be slightly different.

The thickness of the frame portion 23b (the depth of the recess R1), or the height from the first substrate surface 23c to the lower surface 407c of the main body of the temperature sensing element 407 described later, can be appropriately set according to, for example, the thickness of the crystal element 5. In this embodiment, unlike the first to third embodiments, the temperature sensing element 407 may not be accommodated in the sealed space formed by the recess R1. Therefore, in the setting of the above-mentioned dimensions such as the depth of the recess R1, the thickness of the temperature sensing element 407 may also be set as an exception. Thus, the above-mentioned dimensions may be, for example, the same as those of the conventional resonator. Of course, the description of the dimensions such as the depth of the recess R1 described in the description of the first embodiment can also be referred to in this embodiment.

The size of the recess R1 when viewed from above can be appropriately set, for example, by considering the size of the crystal element 5 when viewed from above, as in the first embodiment. In this embodiment, unlike the first to third embodiments, the temperature sensing element 407 may not be accommodated in the sealed space formed by the recess R1. Therefore, in setting the size of the recess R1 when viewed from above, the thickness of the temperature sensing element 407 may also be set as an exception. Of course, the size of the temperature sensing element 407 when viewed from above may also be considered as needed. In addition, the above situation does not prevent the description of the size of the recess R1 when viewed from above in the first embodiment from being applied to this embodiment.

Regarding the chip-type temperature sensing element 407, as long as no contradiction occurs, the description of the chip-type temperature sensing element 207 of the second embodiment can be appropriately cited. For example, the temperature sensing element 407 has an element body 407a and a pair of element terminals 407b in the same manner as the temperature sensing element 207. The element body 407a is applied with a voltage, for example, via the two element terminals 407b. In addition, in another viewpoint, the element body 407a outputs a signal of a strength corresponding to the temperature from at least one of the two element terminals 407b.

The two element terminals 407b are exposed, for example, outside the element body 407a (more specifically, on the mounting base 11Z side (-D3 side)). In this case, the element terminal 407b may be, for example, a layered conductor overlapping the surface on the -D3 side of the element body 407a (sometimes referred to as the body lower surface 407c), or a conductor having at least a portion exposed on the body lower surface 407c (not necessarily limited to a layered conductor). The material of the element terminal 407b is arbitrary, and for example, the description of the materials of various conductors of the mounting base 11 (11Z) may be applied to the material of the element terminal 407b.

In addition, the description of the position, shape and size of the temperature sensing element 407 in the embodiment can be referred to the position, shape and size of the element body 407a unless otherwise specified and unless there is any contradiction. Furthermore, whether the element body 407a is composed of only the functional part or has no parts other than the functional part (such as the sealing part), the description of the position, shape and size of the temperature sensing element 407 can also be referred to the position, shape and size of the functional part unless otherwise specified.

The shape and size of the temperature sensing element 407 are arbitrary as long as the recess R1 can be sealed similarly to the cover 13 of the first to third embodiments. The description regarding the shape and size of the cover 13 can be applied to the temperature sensing element 407 .

The mounting base 11Z and the temperature sensing element 407 are joined to hermetically seal the recess R1, and are joined to electrically connect the two element terminals 407b of the temperature sensing element 407 to the two terminals 3 of the mounting base 11Z. The description of the joining of the cover 13 and the mounting base 11 in the first embodiment can be used for the joining for sealing. The description of the joining of the temperature sensing element 7 and the mounting base 11 in the first embodiment can be used for the joining for electrical connection. At this time, the term of the external electrode 7b in the first embodiment can be replaced with the term of the element terminal 407b.

As described in the first embodiment, when the sealing material 33 is conductive, the sealing material 33 may be separated from the two connection electrodes 31, or may be connected to one of the two connection electrodes 31 (the connection electrode 31 on the +D1 side in the example shown in the figure) on the frame upper surface 23e. The latter is illustrated in the example of FIG. 9.

The two connection electrodes 31 are electrically connected to the two terminals 3 via two wirings 27. It has been described that the wiring 27 can be set to various structures. In the example of Figure 11, the wiring 27 that connects the connection electrode 31 located on the side opposite to the pad 25 (+D1 side) in the long side direction of the mounting base 11 to the terminal 3 is composed only of a via conductor that penetrates the frame portion 23b and the substrate portion 23a. In addition, the connection electrode 31 located on the pad 25 side (-D1 side) is composed of a via conductor that penetrates the frame portion 23b, a conductor layer located on the lower surface of the frame portion 23b, and a via conductor that penetrates the substrate portion 23a (not shown).

(4.2. Other Examples According to the Fourth Embodiment)

(4.2.1. Other examples related to connecting electrodes)

12A, 12B, and 13 are plan views of mounting bases 11A, 11B, and 11C according to other examples. The crystal element 5 is also shown in these drawings.

As described above, the position, shape, and size of the connecting electrode 31 (the element terminal 407b in another viewpoint) can be set to various. FIG. 12A, FIG. 12B, and FIG. 13 are diagrams showing examples of the position, shape, and size of the connecting electrode 31 different from those shown in FIG. 9 to FIG. 11. Specifically, as described below. In addition, although not specifically shown in the figure, the position, shape, and size of the element terminal 407b connected to the connecting electrode 31 involved in other examples are roughly the same as the position, shape, and size of the connecting electrode 31 involved in other examples.

In the example shown in FIG. 12A , the two connection electrodes 31 are located outside the first metal layer 35 (sealing material 33 in another viewpoint) in contrast to the embodiment. However, one connection electrode 31 (the connection electrode 31 on the +D1 side) is connected to the first metal layer 35. In this case, as described above, the two may be formed of different materials or may be formed integrally of the same material.

The description of the position, shape and size of the connection electrode 31, the element terminal 407b, and the sealing material 33 (the first metal layer 35 and/or the second metal layer 37) in the embodiment (for example, refer to the description of the first embodiment cited in the fourth embodiment. The same applies hereinafter.) can be referred to the example shown in FIG. 12A as long as there is no contradiction. However, it is reasonable to replace the terms such as the inner edge and the outer edge appropriately.

For example, in the description of the embodiment, it is described that the entire outer edge of the sealing material 33 may be consistent with the outer edge of the frame upper surface 23e, or a part or all of it may be separated from the outer edge of the frame upper surface 23e. In the example of FIG. 12A , the entire inner edge of the sealing material 33 may be consistent with the inner edge of the frame upper surface 23e, or a part or all of it may be separated from the inner edge of the frame upper surface 23e.

In addition, for example, in the description of the embodiment, it is described that the inner edge of the sealing material 33 is separated from the inner edge of the frame upper surface 23e at least in the configuration area of the connecting electrode 31 (except for the portion where one connecting electrode 31 is regarded as a part of the first metal layer 35). In the example of FIG. 12A, the outer edge of the sealing material 33 is separated from the outer edge of the frame upper surface 23e at least in the configuration area of the connecting electrode 31 (except for the portion where one connecting electrode 31 is regarded as a part of the first metal layer 35).

In the example of FIG. 12A , the first metal layer 35 (sealing material 33) is located on the side where the connecting electrode 31 is located (the short side in the example shown in the figure), so that its inner edge is consistent with the inner edge of the upper surface 23e of the frame. On the side where the connecting electrode 31 is not located (the long side in the example shown in the figure), the outer edge of the first metal layer 35 (sealing material 33) is consistent with the outer edge of the upper surface 23e of the frame, and also has a width narrower than the width of the upper surface 23e of the frame. As can be seen from the description so far, the position and width of the first metal layer 35 (sealing material 33) are not limited to the illustrated method. For example, the first metal layer 35 (sealing material 33) may also have a width equal to the width of the upper surface 23e of the frame on the side where the connecting electrode 31 is not located.

In the example shown in FIG12B, the two connection electrodes 31 are located outside the first metal layer 35, similarly to the example shown in FIG12A. However, any connection electrode 31 is far from the first metal layer 35. In the example of FIG12B, similarly to the example of FIG12A, the description of the position, shape, and size of the connection electrode 31, the element terminal 407b, and the sealing material 33 (the first metal layer 35 and/or the second metal layer 37) in the embodiment can be referred to while replacing the inner edge and the outer edge.

In the example of FIG. 12B , the first metal layer 35 (sealing material 33) is located on the side where the connecting electrode 31 is located (the short side in the example shown in the figure), and its inner edge is consistent with the inner edge of the upper surface 23e of the frame portion, as in the example of FIG. 12A . On the side where the connecting electrode 31 is not located (the length in the example shown in the figure), the first metal layer 35 (sealing material 33) has a width narrower than the width of the upper surface 23e of the frame portion, as in FIG. 12A . However, unlike the example of FIG. 12A , the inner edge of the first metal layer 35 (sealing material 33) is consistent with the inner edge of the upper surface 23e of the frame portion. As can be seen from the description so far, the position and width of the first metal layer 35 (sealing material 33) are not limited to the illustrated method. For example, the first metal layer 35 (sealing material 33) may also have a width equal to the width of the upper surface 23e of the frame portion on the side where the connecting electrode 31 is not located.

In the example shown in FIG13 , the two connection electrodes 31 are located inside the first metal layer 35 , similarly to the examples shown in FIG9 to FIG11 . However, all the connection electrodes 31 are separated from the first metal layer 35 .

Although not particularly shown in the figure, one connection electrode 31 may be located inside the first metal layer 35 , and one connection electrode 31 may be located outside the first metal layer 35 .

In FIGS. 9 to 11, a method is illustrated in which one connection electrode 31 is connected to the first metal layer 35, and both of the two element terminals 407b are not connected to the second metal layer 37. However, one element terminal 407b connected to one connection electrode 31 connected to the first metal layer 35 may be connected to the second metal layer 37. In addition, contrary to the example shown in the figure, both of the two connection electrodes 31 are not connected to the first metal layer 35, and one element terminal 407b is connected to the second metal layer 37. In addition, both of the two connection electrodes 31 are not connected to the first metal layer 35, and both of the two element terminals 407b are not connected to the second metal layer 37. The above situation can be established in any method of a method in which at least one connection electrode 31 is located inside the sealing material 33, and a method in which at least one connection electrode 31 is located outside the sealing material 33.

(4.2.2. Other examples related to the component body)

FIG. 14A, FIG. 14B, FIG. 15A, FIG. 15B, and FIG. 15C are cross-sectional views showing a portion of crystal resonators 401D, 401E, 401F, 401G, and 401H according to other examples. These figures correspond to the upper portion of FIG. 11. In addition, in these drawings, the configuration of the embodiment is taken as an example regarding the configuration of the connection electrode 31, etc. when viewed from above. However, the configuration of the connection electrode 31, etc. when viewed from above may also be the example described with reference to FIG. 12A to FIG. 13.

In the example shown in FIG. 14A , the shape of the temperature sensing element 407D (element body 407a) is a shape other than a flat plate. Specifically, the area of the temperature sensing element 407D that is opposite to the recess R1 is thicker on the side of the recess R1 relative to other areas. With such a structure, for example, the volume of the element body 407a can be ensured at a position close to the crystal element 5, or the element body 407a can be brought close to the crystal element 5. From another point of view, by thinning the area overlapping with the upper surface 23e of the frame portion of the element body 407a, the package 409D can be made thinner.

In the temperature sensing element 407D, the width and thickness of the thickened area are arbitrary. In the illustrated example, the thickened area is smaller than the recess R1 when viewed from above, and is located on the central side of the recess R1. Therefore, the thickened area is separated from the inner peripheral surface of the recess R1. However, the thickened area may also have the same width as the recess R1, or have the same length as the recess R1 in any direction, thereby embedding the recess R1. In addition, the thickness of the thickened area may be, for example, 1.2 times or more, 1.5 times or more, or 2 times or more relative to the thickness of the area overlapping with the upper surface 23e of the frame. As long as the temperature sensing element 407D does not contact the crystal element 5, there is no particular upper limit.

In the example shown in FIG. 14B , the shape of the temperature sensing element 407E (element body 407a) is set to a shape other than a flat plate, similarly to the example in FIG. 14A . However, in contrast to the example in FIG. 14A , the temperature sensing element 407E has a region (frame-shaped region) overlapping with the frame upper surface 23e that is thicker on the frame upper surface 23e side relative to other regions. With such a structure, for example, the strength of the temperature sensing element 407E can be ensured. In addition, compared with the case where the temperature sensing element 407E is made thicker as a whole, the volume of the space in the package 409E can be ensured.

In the temperature sensing element 407E, the width of the thickened area can be equal to the width of the upper surface 23e of the frame portion, as shown in the example shown in the figure, or it can be further extended to the side of the recess R1. In this case, for example, in a top view, the inner edge of the thickened area can be closer to the outside than the outer edge of the crystal element 5. In addition, in the temperature sensing element 407E, the thickness of the thickened area is arbitrary. For example, the thickness of the thickened area can be set to more than 1 times, more than 1.5 times, or more than 2 times the thickness of the area opposite to the recess R1. There is no particular upper limit.

In the examples of FIGS. 9 to 11 , 14A and 14B , the temperature sensing element (407, etc.) does not contact the mounting base 11Z in the direction along the bottom surface of the recess R1 (in the direction along the D1-D2 plane). For example, the temperature sensing element (407, etc.) does not contact the mounting base 11Z in the recess R1 and on the outer peripheral surface of the mounting base 11Z. On the other hand, the examples shown in FIGS. 15A to 15C are examples of a method in which the temperature sensing element (407, etc.) contacts the mounting base (11F, etc.) in the direction along the D1-D2 plane. Specifically, it is as follows.

In the package 409F shown in FIG. 15A , the temperature sensing element 407 is set to be accommodated in a width at a position closer to the inside than the outer edge of the frame 23b when viewed from above. In addition, on the upper surface of the frame 23b, the area opposite to the temperature sensing element 407 is lower than the area outside thereof (frame-shaped area). Moreover, the temperature sensing element 407 is embedded in the interior of the upper end of the frame 23b (the upper end of the recess R1). The joint for sealing and the joint for electrical connection between the temperature sensing element 407 and the mounting base 11F can be performed, for example, in the same manner as in the first embodiment, in the area where the temperature sensing element 407 and the upper surface of the frame 23b overlap each other.

In the frame 23b, the width of the relatively low area (the length from the inner edge to the outer edge) and the width of the relatively high area are arbitrary, for example, the two can be the same as each other, or one can be larger than the other. In addition, in the frame 23b, the difference in height between the relatively low area and the relatively high area is also arbitrary. For example, in association with the difference in height between the two, the height of the upper surface of the temperature sensing element 407 (the position in the direction of D3) can be lower than the height of the relatively high area of the frame 23b (the position in the direction of D3), can be equal (the example shown in the figure), or can be higher.

In addition, in the frame portion 23b, the method of making the first region in the upper surface lower than the second region can be various methods. For example, similarly to the formation of the recess R1, the second region can be relatively raised by stacking ceramic green sheets on the second region, or the first region can be relatively lowered by punching. In addition, the first region can be relatively lowered by grinding, grinding, cutting or laser processing. The same is true in other examples.

In the package 409G shown in FIG15B , the region on the inner edge side (frame-shaped region) of the upper surface of the frame 23b is lower than the region on the outer edge side. On the other hand, the temperature sensing element 407G has a convex portion 407g protruding toward the frame 23b side over the region (frame-shaped region) opposite to the region on the inner edge side. Furthermore, the convex portion 407g is embedded in the interior of the upper end of the frame 23b (the upper end of the recess R1).

The width (length from the inner edge to the outer edge) and the protrusion (length in the direction D3) of the convex portion 407g are arbitrary. For example, the width of the convex portion 407g can be less than 1/2, about 1/2, or more than 1/2 relative to the width of the frame portion 23b. In addition, the protrusion of the convex portion 407g can be smaller, equal, or larger than the thickness of the area outside the configuration area of the convex portion 407g of the temperature sensing element 407. The description in this paragraph can be referenced to the convex portion 407h (Figure 7C) described later.

15B, the sealing bonding and the electrical connection bonding between the temperature sensing element 407G and the mounting base 11G are performed, for example, in the area outside the protrusion 407g. However, at least one of the sealing bonding and the electrical connection bonding may be performed in the protrusion 407g.

In the package 409H shown in FIG15C , the upper surface of the frame 23b is opposite to the example of FIG15B , and the area on the outer edge side (frame-shaped area) is lower than the area on the inner edge side. On the other hand, the temperature sensing element 407H has a convex portion 407h protruding toward the frame 23b side throughout the area (frame-shaped area) opposite to the area on the outer edge side. Moreover, the convex portion 407h surrounds the upper end of the frame 23b.

15C, the bonding for sealing and the bonding for electrical connection between the temperature sensing element 407H and the mounting base 11H are performed, for example, in the area inside the protrusion 407h. However, at least one of the bonding for sealing and the bonding for electrical connection may be performed in the protrusion 407h.

In Fig. 15A to Fig. 15C, the bonding for sealing and the bonding for electrical connection are performed in the area facing the +D3 side of the upper surface of the frame portion 23b. However, instead of or in addition to this bonding, the bonding for sealing and/or the bonding for electrical connection may be performed in the area facing the inner circumference or outer circumference of the step on the upper surface of the frame portion 23b.

For example, a structure in which a portion of the temperature sensing element 407D in FIG. 14A (eg, a region away from the inner peripheral surface of the recess R1 ) is thickened may be combined with the examples in FIG. 15A , FIG. 15B , and FIG. 15C .

(4.3. Summary of the Fourth Embodiment)

As described above, the piezoelectric device (crystal resonator 401) includes a piezoelectric element (crystal element 5), a mounting base 11 (represented by 11Z or the like, and this reference numeral is sometimes used), and a temperature sensing element 407. The temperature sensing element 407 has a portion (in the example shown in the figure, the entire temperature sensing element 407) located on the upper end side of the recess R1 relative to the crystal element 5. Therefore, for example, as described above, the possibility that the temperature sensing element 207 is excessively affected by the heat from the bottom surface side of the recess R1 is reduced. As a result, it can be expected that the measured temperature follows the temperature of the crystal element 5.

The temperature sensing element 407 can hermetically seal the recess R1 .

In this case, for example, it is advantageous to miniaturize the resonator 401. In addition, the same effects as those of the first embodiment can be obtained. For example, when the crystal element 5 and the mounting base 11 are determined to be defective by the inspection before sealing, the temperature sensing element 407 will not be wasted. In addition, for example, the temperature sensing element 407 will not be cut off by the laser.

The temperature sensing element 407 may not abut against the mounting base 11 in the direction along the bottom surface of the recess R1 (in the direction along the D1-D2 plane) (see FIGS. 9 to 11, 14A, and 14B). For example, the temperature sensing element (407, etc.) does not abut against the mounting base 11 in the recess R1 and on the outer peripheral surface of the mounting base 11.

In this case, for example, relative displacement of the two is allowed along the D1-D2 plane when the outer periphery of the temperature sensing element 407 is joined to the frame portion 23b of the mounting base 11. As a result, thermal stress generated between the temperature sensing element 407 and the mounting base 11 can be expected to be reduced.

The temperature sensing element 407 may have a portion embedded in the upper end of the recess R1 (see FIGS. 15A and 15B ).

In this case, for example, the positioning accuracy of the temperature sensing element 407 and the mounting base 11 is improved. As a result, for example, the possibility of an unwanted short circuit between the element terminal 407b and the conductive sealing material 33 is reduced. In addition, for example, the accuracy of the relative position of the element body 407a and the crystal element 5 is improved, and the accuracy of measuring the temperature is improved. In addition, for example, when viewed in section, the boundary surface between the temperature sensing element 407 and the mounting base 11 is not planar, but has a curved portion, so the sealing is improved. In addition, for example, as described in the description of FIG. 14A, when the area of the temperature sensing element 407D overlapping with the recess R1 is made thicker as a whole and the temperature sensing element 407D is embedded in the upper end of the recess R1, it is easy to ensure the volume of the temperature sensing element 407D.

The temperature sensing element 407 may include a portion surrounding the upper end of the mounting base 11 from the outer peripheral side (see FIG. 15C ).

In this case, for example, similar to the above-mentioned method in which the temperature sensing element 407 has a portion embedded in the upper end of the recess R1, the positioning accuracy of the temperature sensing element 407 and the mounting base 11 can be improved, and the boundary surface between the temperature sensing element 407 and the mounting base 11 can be curved to improve the sealing performance. In addition, for example, by strengthening the edge of the temperature sensing element 407, the possibility of cracks from the edge can be reduced.

The temperature sensing element 407 may include an element body 407a and two element terminals 407b exposed outside the element body 407a. The mounting base 11 may include a substrate portion 23a, a frame portion 23b, and two connection electrodes 31. The substrate portion 23a may include a bottom surface of a recess R1. The frame portion 23b may include an inner peripheral surface of the recess R1. The two connection electrodes 31 may be located at the upper end of the frame portion 23b and may be joined to the two element terminals 407b. The upper ends of the element body 407a and the frame portion 23b may be joined to each other in a sealing area (a configuration area of the sealing material 33) extending in a ring shape along the upper end of the frame portion 23b. At least one of the two connection electrodes 31 may be located at a position closer to the inner peripheral side than the above-mentioned sealing area (sealing material 33) (refer to FIGS. 9 to 11 and 13).

In this case, for example, the connection electrode 31 located on the inner peripheral side of the sealing material 33 is sealed and protected together with the crystal element 5. As a result, for example, the durability of the resonator 401 is improved. In addition, for example, since the bonding of the element terminal 407b and the connection electrode 31 and the bonding for sealing are both performed on the upper surface of the frame portion 23b, both can be performed at the same time.

In addition, at least one of the two connection electrodes 31 may be located on the outer peripheral side of the sealing region (sealing material 33 ) (see FIGS. 12A and 12B ).

In this case, for example, it is easy to position the element terminal 407b at the end of the element body 407a. On the other hand, a general temperature sensing element has element terminals at both ends. Therefore, it is possible to use a temperature sensing element that has already been circulated as the temperature sensing element 407, or to reduce the design changes from the previous temperature sensing element to the temperature sensing element 407.

The mounting base 11 may include a first metal layer 35. The first metal layer 35 may be located at the upper end of the frame portion 23b, may extend along the upper end of the frame portion 23b and be in a ring shape, or may be a sealing metal layer joined to the element body 407a (directly or indirectly via the second metal layer 37). One of the two connection electrodes 31 may be connected to the first metal layer 35 at the upper end of the frame portion 23b.

In this case, for example, it is easy to ensure the area of the connection electrode 31 connected to the first metal layer 35 and/or the first metal layer 35. In addition, the method of connecting one connection electrode 31 to the first metal layer 35 may include a method of including one connection electrode 31 in the first metal layer 35.

(5. Specific example of wiring in package)

As described above, the positions of the pads 25 and the connecting electrodes 31 when viewed from above are arbitrary, and the positional relationship between the terminals 3 connected to the pads 25 and the terminals 3 connected to the connecting electrodes 31 when viewed from above is also arbitrary. The wiring 27 can be configured in various structures according to the configuration of the pads 25, the connecting electrodes 31, and the terminals 3, and further, can be configured in various structures when the pads 25, the connecting electrodes 31, and the terminals 3 are configured in a specific configuration. A specific example of the structure of the wiring 27 when the pads 25, the connecting electrodes 31, and the terminals 3 are configured in a specific configuration is shown below. In addition, in the drawings referred to in the following description, for convenience, the via conductors that are hidden in the layered conductors and cannot be seen are sometimes indicated by solid lines instead of dotted lines.

Fig. 16 is a perspective view showing a specific example of the wiring 27. This figure corresponds to a part of Fig. 1 .

In the example of FIG. 16 , the two terminals 3 connected to the two pads 25 are located at two diagonal corners of the second substrate surface 23 d, and the two terminals 3 connected to the two connection electrodes 31 are located at the other two diagonal corners. In addition, in the example of FIG. 16 , similarly to the example of FIG. 1 , the two pads 25 are located on one side (-D1 side) of the long side direction of the first substrate surface 23 c and are arranged along the short side direction (D2 direction). The two connection electrodes 31 are located on the other side (+D1 side) of the long side direction of the first substrate surface 23 c and are arranged along the short side direction (D2 direction).

The wiring 27A connecting one of the two pads 25 (pad 25A on the -D1 side and -D2 side in the example of FIG. 16 ) to the terminal 3 is composed of a via-hole conductor 27b that penetrates the substrate portion 23a in the thickness direction. One end of the via-hole conductor 27b is connected to the pad 25A, and the other end is connected to the terminal 3 located at the -D1 side and -D2 side. The wiring 27B connecting the other of the two pads 25 (pad 25B on the -D1 side and +D2 side in the example of FIG. 16 ) to the terminal 3 is composed of a layered conductor 27a extending from the pad 25B to the other side (+D1 side) in the long side direction and a via-hole conductor 27b that penetrates the substrate portion 23a in the thickness direction at a position overlapping with the layered conductor 27a. The layered conductor 27a overlaps with the first substrate surface 23c. One end of the via-hole conductor 27b is connected to the layered conductor 27a, and the other end is connected to the terminal 3 located at the +D1 side and +D2 side. Through these two wirings 27 , the two pads 25 are connected to the terminals 3 located at two diagonal positions.

The wiring 27C connecting one of the two connection electrodes 31 (the connection electrode 31A on the +D1 side and the -D2 side in the example of FIG. 16 ) to the terminal 3 is composed of a via-hole conductor 27d that penetrates the substrate portion 23a and the frame portion 23b in the thickness direction. One end of the via-hole conductor 27d is connected to the connection electrode 31A, and the other end is connected to the terminal 3 located on the +D1 side and the -D2 side. The wiring 27D connecting the other of the two connection electrodes 31 (the connection electrode 31B on the +D1 side and the +D2 side in the example of FIG. 16 ) to the terminal 3 is composed of a layered conductor 27c extending from the connection electrode 31 to the first metal layer 35 (in another viewpoint, the sealing material 33. The following descriptions of FIG. 16 to FIG. 18 are the same as long as there is no contradiction.), the first metal layer 35, and the via-hole conductor 27d that penetrates the substrate portion 23a and the frame portion 23b in the thickness direction at a position overlapping with the first metal layer 35. The layered conductor 27c overlaps the frame upper surface 23e. One end of the via conductor 27d is connected to the first metal layer 35, and the other end is connected to the terminal 3 located on the -D1 side and the +D2 side. Through these two wirings 27, the two connection electrodes 31 are connected to the terminals 3 located at two diagonal positions.

In addition, part or all of the layered conductor 27a of the wiring 27B may overlap with the frame 23b (or may be located between the substrate 23a and the frame 23b). The direction and shape of the layered conductor 27c of the wiring 27D are arbitrary. In the example of FIG. 16, the layered conductor 27c extends to the +D1 side (the short side of the outer edge of the frame 23b). Unlike the example shown in the figure, the layered conductor 27c may extend to the +D2 side (the length side of the outer edge of the frame 23b), for example. In addition, the layered conductor 27c may have the same length as the length of the D2 direction of the connecting electrode 31 and extend to the +D1 side. The material and/or thickness of the layered conductor 27c may be the same as or different from the material and/or thickness of the connecting electrode 31 and/or the first metal layer 35. From the viewpoint of material, thickness, planar shape, etc., the layered conductor 27c may not be clearly distinguished from the connecting electrode 31 and/or the first metal layer 35. In addition to or instead of the via-hole conductor 27d of the wiring 27D, a layered conductor arranged on the inner surface of the castellation structure may be used.

The terminal 3 connected to the connection electrode 31B may be assigned a reference potential, for example. When the recess R1 of the mounting base 11 of FIG. 16 is blocked by a conductive cover 13 (in other words, not the temperature sensing element 407 of the fourth embodiment), the first metal layer 35 may help to assign a reference potential to the cover 13 via the second metal layer 37. Of course, as described above, the cover 13 may not be conductive and may not be assigned a reference potential. In addition, the connection electrode 31B may be assigned a potential other than the reference potential.

Fig. 17 is a perspective view showing another specific example of the wiring 27. This figure is the same as Fig. 16 .

In the example of FIG. 17 , only the structure of the wiring 27D is different from that of the example of FIG. 16 . The wiring 27D does not include the first metal layer 35. In another viewpoint, the connection electrode 31B is not electrically connected to the first metal layer 35. Specifically, the wiring 27D is composed of a layered conductor 27c extending from the connection electrode 31B to the -D1 side and a via conductor 27d overlapping the layered conductor 27c. One end of the via conductor 27b is connected to the layered conductor 27c, and the other end is connected to the terminal 3 located on the -D1 side and on the +D2 side.

16 and 17 , for example, the wiring 27 whose potential changes when viewed from above can be easily positioned inside the sealing material 33. As a result, for example, the wiring 27 can be easily sealed or electromagnetically shielded.

Fig. 18 is a plan view showing still another specific example of the wiring 27. This figure is the same as Fig. 12A.

In the example of FIG. 18, as in the example of FIG. 16, the two terminals 3 connected to the two pads 25 are located at two diagonal corners of the second substrate surface 23d, and the two terminals 3 connected to the two connection electrodes 31 are located at the other two diagonal corners. The positions of the two pads 25 and the two connection electrodes 31 are as described with reference to FIG. 12A, etc. In the example of FIG. 18, the wirings 27A and 27B are the same as those in the example of FIG. 16.

The wiring 27C that connects one of the two connection electrodes 31 (the connection electrode 31C located on the -D1 side in the example of FIG. 18 ) to the terminal 3 is composed of a via-hole conductor 27d that penetrates the substrate portion 23a and the frame portion 23b in the thickness direction. One end of the via-hole conductor 27d is connected to the connection electrode 31C, and the other end is connected to the terminal 3 located on the -D1 side and the +D2 side. The wiring 27C that connects the other of the two connection electrodes 31 (the connection electrode 31D located on the +D1 side in the example of FIG. 18 ) to the terminal 3 is composed of a via-hole conductor 27d that penetrates the substrate portion 23a and the frame portion 23b in the thickness direction. One end of the via-hole conductor 27d is connected to the connection electrode 31D, and the other end is connected to the terminal 3 located on the +D1 side and the -D2 side. Through these two wirings 27, the two connection electrodes 31 are connected to the terminals 3 located at two diagonals.

In addition, in the example of FIG. 18 , the connection electrode 31D is connected to the first metal layer 35. Therefore, the upper end of the via conductor 27d of the wiring 27D may be connected to the first metal layer 35 together with the connection electrode 31D (the example shown in the figure), or may be connected only to the connection electrode 31D, or may be connected only to the first metal layer 35. In addition to or instead of the via conductor 27d of the wiring 27C and/or 27D, a layered conductor arranged on the inner surface of the castellated structure may be used. The terminal 3 connected to the connection electrode 31D may be assigned a reference potential, for example. Of course, as described above, the connection electrode 31D may also be assigned a potential other than the reference potential.

According to the specific example of the wiring 27 in Fig. 18, for example, it is easy to avoid the wirings 27 having different potentials from crossing each other. As a result, the electrical interference between the wirings 27 is reduced. In turn, the characteristics of the resonator are improved.

(6. Example of using a crystal resonator)

19 is a schematic diagram showing an example of use of the crystal resonator 1. In addition, for convenience, the reference numerals of the first embodiment are used, but the description here can also be applied to other embodiments.

As shown in the cross-sectional view of the lower stage of FIG. 19 , the resonator 1 is mounted on, for example, a circuit substrate 53 for use. More specifically, as described above, the terminals 3 that are opposed to each other are bonded to the unillustrated pads on the upper surface of the circuit substrate 53 by means of a conductive bonding material (reference numerals omitted) therebetween. In addition, the resonator 1 may be mounted on a substrate other than the circuit substrate 53. For example, the resonator 1 may be mounted on a substrate having a shape that deviates from the concept of a substrate (for example, a substrate constituting a package). In addition, in the description herein, the term circuit substrate 53 may be replaced with the term substrate, which is a higher-level concept thereof, as long as no contradiction or the like is caused.

The resonator 1 mounted on the circuit substrate 53 may be sealed with an insulating sealing material 55 (the example shown in the figure) or not. As the material of the sealing material 55, for example, resin can be cited. An insulating (or conductive) filler may also be mixed in the resin. The physical properties of the sealing material 55 (for example, thermal insulation and rigidity) can be appropriately set. The sealing material 55, for example, covers the upper surface and side surfaces of the resonator 1 and is bonded to the upper surface of the circuit substrate 53. The sealing material 55 may be sandwiched between the resonator 1 and the circuit substrate 53 or not. Unlike the example shown in the figure, the sealing material 55 may not cover the upper surface of the resonator 1. The sealing material 55 may also seal other electronic components mounted on the circuit substrate 53 together with the resonator 1.

The circuit substrate 53 has, for example, a wiring board (e.g., a printed wiring board) and one or more electronic elements mounted or built into the wiring board. Examples of electronic elements include integrated circuit elements (IC: Integrated Circuit), capacitors, inductors, and resistors. Moreover, as shown in the upper section of FIG. 19 , the circuit substrate 53 has various circuits (53a to 53d) composed of one or more electronic elements. In addition, for convenience, it is referred to as a "circuit", but part or all of the various circuits can also be realized by executing a program by a processor. The circuits possessed by the circuit substrate 53 are, for example, as described below.

The oscillation circuit 53a generates an oscillation signal by applying an alternating current to the crystal element 5. The temperature compensation circuit 53b (abbreviated as "compensation circuit" in FIG. 19 ) compensates for the change in the frequency characteristic of the crystal element 5 caused by the temperature by inputting a signal corresponding to the detection temperature detected by the temperature sensing element 7 to the oscillation circuit 53a. In more detail, the temperature sensing element 7 outputs an analog signal having a signal level (such as voltage or current) corresponding to the temperature. The A/D circuit 53d converts the analog signal from the temperature sensing element 7 into a digital signal and outputs it. The conversion circuit 53c converts the value of the digital signal from the A/D circuit 53d into a temperature and outputs it to the compensation circuit 53b. In addition, the combination of the resonator 1 and the circuit substrate 53 (at least the oscillation circuit 53a in the circuit of the circuit substrate 53 in another viewpoint) can be understood as an oscillator 53.

In the above embodiments and other examples, the crystal resonators 1, 1C, 1D, 1E, 201, 301, 401, 401D, 401E, 401F, 401G, and 401H are examples of piezoelectric devices, respectively. The crystal element 5 is an example of a piezoelectric element.

The technology involved in the present disclosure is not limited to the above-mentioned embodiments, and can be implemented in various forms.

The piezoelectric body is not limited to a crystal. For example, the piezoelectric body may be another single crystal or a piezoelectric body composed of polycrystals (such as ceramics). In addition, a crystal in which an appropriate dopant is added is a type of crystal.

Piezoelectric devices are not limited to crystal resonators (piezoelectric resonators). For example, in addition to piezoelectric elements (such as crystal elements), piezoelectric devices may also be oscillators having integrated circuit elements (IC: Integrated Circuit) that generate oscillation signals by applying voltage to piezoelectric elements. In addition, piezoelectric devices may not contribute to the generation of oscillation signals. For example, piezoelectric devices may be gyro sensors. In addition, piezoelectric devices may also have piezoelectric elements, temperature sensing elements, and electronic elements other than ICs.

As can be seen from the above, the number of pads (e.g., pad 25 and connection electrode 31) and the number of external terminals (e.g., terminal 3) of the piezoelectric device are arbitrary, and the connection relationship between the plurality of pads and the plurality of external terminals is also arbitrary. For example, in an oscillator, the piezoelectric element and the temperature sensing element may be electrically connected to the IC instead of the external terminal of the piezoelectric device.

In a piezoelectric device, the structure of the package that encapsulates the piezoelectric element can be set to an appropriate structure. For example, the package can also be a package with an H-shaped cross-section having recessed portions on the upper surface and the lower surface. In this case, for example, the above-mentioned IC can be installed in the recessed portion of the lower surface. In addition, the package can also have a constant temperature bath. In addition, the piezoelectric device may not be a surface-mounted device, for example, it may be a through-hole mounted device. Regardless of whether the piezoelectric device is surface-mounted, the external terminal of the package (terminal 3 in the embodiment) may not be layered, for example, it may be a pin-shaped.

The mounting method of the piezoelectric element relative to the mounting base can be set in various ways. For example, the piezoelectric element can also be supported at both ends by two conductive bonding materials bonded to two lead electrodes. In addition, for example, the piezoelectric element can also be bonded to a conductive bonding material at one lead electrode, and a bonding wire at one lead electrode. In addition, as a bonding material for supporting one end or both ends of the piezoelectric element, an insulating (can also be conductive) bonding material bonded to a region different from the region of the lead electrode can also be used.

As another example involved in the fourth embodiment, a structure is shown in which at least one of the connecting electrodes 31 (the element terminal 407b in another viewpoint) is located outside the sealing material 33 (FIG. 12A, FIG. 12B and FIG. 18). In the first embodiment, at least one of the two external electrodes 7b may be located outside the sealing material 33. Such a method can be performed, for example, as can be seen from the method in which the sealing material 33C of FIG. 5A is joined to the cover body 13 via the temperature-sensitive film 7a. In the method in which the lower surface 13b of the cover body and the sealing material 33 are insulating, only the external electrode 7b (or the relay conductor connecting the external electrode 7b to the functional part) may be extended from the inside of the sealing material 33 to the outside of the sealing material 33.

As in the third embodiment (FIG. 8), the temperature sensing element located on the wall of the recess may also be a temperature sensing element having a temperature sensing film as in the first embodiment. Even in this case, since the temperature sensing film has a portion located on the cover side compared to the piezoelectric element, for example, the influence of the temperature on the measured temperature on the bottom side of the recess can be reduced. Such a temperature sensing film may overlap with the inner peripheral surface of the wall of the recess, or may overlap with the upper surface of the first frame portion 23ba (however, located above the crystal element 5) as in the case of the connection electrode 31 in the third embodiment.

The temperature sensing element (407, etc.) of the fourth embodiment that functions as a cover for sealing the recessed portion may not be electrically connected to the mounting base (terminal 3 in another viewpoint). For example, an element terminal may be provided on the upper surface of the temperature sensing element (the surface on the opposite side of the recessed portion), and the element terminal may be electrically connected to the circuit substrate 53 on which the piezoelectric device is mounted by a bonding wire.

When the temperature sensing element hermetically seals the recess, the temperature sensing element may not necessarily be applicable to the concept of a chip-type element (see the fourth embodiment). For example, as in the first embodiment, a temperature sensing element composed of a cover and a temperature sensing film may be formed by providing a temperature sensing film (e.g., a thin film thermistor) on the surface of the mounting base side of a cover that is the same or similar to the cover of a conventional piezoelectric device.

In the description of the embodiments, the following effects are particularly focused on: by locating the temperature sensing element on the opposite side of the bottom surface of the recess relative to the piezoelectric element, the influence of the temperature on the bottom surface of the recess on the measured temperature is reduced, and the measured temperature easily follows the temperature of the piezoelectric element. However, such an effect may not necessarily be exerted. Even if such an effect is not exerted, various effects can be achieved by locating the temperature sensing element at a position closer to the upper end side of the recess than the piezoelectric element. For example, the degree of freedom of design is increased (the realization of technological enrichment). In addition, in the fourth embodiment (as well as the first embodiment), the temperature sensing element also serves as a cover body, and the piezoelectric device is miniaturized. In the first and fourth embodiments, the influence of the inspection or processing on the temperature sensing element after the piezoelectric element is mounted on the mounting base and before the recess is sealed is reduced.

According to the present disclosure, the following concepts can be extracted.

(Concept 1)

A piezoelectric device having:

Piezoelectric elements;

A mounting base having a recessed portion sealed airtightly, the piezoelectric element being mounted on a bottom surface of the recessed portion; and

The temperature sensing element has a portion located closer to an upper end side of the recess than the piezoelectric element.

(Concept 2)

The piezoelectric device of Concept 1, wherein:

A cover body is also provided for sealing the recessed portion.

(Concept 3)

The piezoelectric device of concept 2, wherein:

The temperature sensing element includes a temperature sensing film overlapping with a surface of the cover body on the mounting base side.

(Concept 4)

The piezoelectric device of concept 3, wherein:

The temperature sensitive film has a portion overlapping with the recessed portion in a plan perspective view.

(Concept 5)

The piezoelectric device according to concept 3 or 4, wherein:

The temperature sensitive film has a portion located outside the recessed portion in a plan perspective view.

(Concept 6)

The piezoelectric device of concept 2, wherein:

The temperature sensing element is a chip-type element mounted on a surface of the cover body on the mounting base side.

(Concept 7)

The piezoelectric device of concept 2, wherein:

The temperature sensing element is a chip-type element mounted on a wall portion of the recess.

(Concept 8)

The piezoelectric device of Concept 1, wherein:

The temperature sensing element hermetically seals the recess.

(Concept 9)

The piezoelectric device of Concept 8, wherein:

The temperature sensing element is a chip-type element.

(Concept 10)

The piezoelectric device according to concept 8 or 9, wherein:

The temperature sensing element and the mounting base do not abut against each other in a direction along the bottom surface of the recessed portion.

(Concept 11)

The piezoelectric device according to concept 8 or 9, wherein:

The temperature sensing element has a portion embedded in an upper end of the recess.

(Concept 12)

The piezoelectric device according to concept 8 or 9, wherein:

The temperature sensing element has a portion surrounding the upper end of the mounting base from the outer peripheral side.

(Concept 13)

The piezoelectric device according to any one of Concepts 8 to 12, wherein:

The temperature sensing element has:

a component body; and

Two component terminals, exposed to the outside of the component body,

The mounting base has:

a substrate portion having a bottom surface of the recessed portion;

a frame portion having an inner peripheral surface of the recessed portion; and

Two connecting electrodes are located at the upper end of the frame and are connected to the two element terminals.

The element body and the upper end of the frame portion are joined to each other in a sealing area extending in an annular shape along the upper end of the frame portion.

At least one of the two connection electrodes is located on the inner peripheral side of the sealing area.

(Concept 14)

The piezoelectric device according to any one of Concepts 8 to 13, wherein:

The temperature sensing element has:

a component body; and

Two component terminals, exposed to the outside of the component body,

The mounting base has:

a substrate portion having a bottom surface of the recessed portion;

a frame portion having an inner peripheral surface of the recessed portion; and

Two connecting electrodes are located at the upper end of the frame and are connected to the two element terminals.

The element body and the upper end of the frame portion are joined to each other in a sealing area extending in an annular shape along the upper end of the frame portion.

At least one of the two connection electrodes is located on the outer peripheral side of the sealing region.

(Concept 1 5)

The piezoelectric device according to any one of Concepts 8 to 14, wherein:

The temperature sensing element has:

a component body; and

Two component terminals, exposed to the outside of the component body,

The mounting base has:

a substrate portion having a bottom surface of the recessed portion;

a frame portion having an inner peripheral surface of the recessed portion;

two connecting electrodes, located at the upper end of the frame portion, and connected to the two element terminals; and

The metal layer for sealing is located at the upper end of the frame, extends along the upper end of the frame and is annular, and is joined to the element body.

One of the two connection electrodes is connected to the metal layer at the upper end of the frame portion.

-Description of Reference Numerals-

1... crystal resonator (piezoelectric device), 5... crystal element (piezoelectric element), 7... temperature sensing element, 11... mounting base, 13... cover, R1... recessed portion.

Claims (15)

1. A piezoelectric device having: Piezoelectric elements; A mounting base having a recessed portion sealed airtightly, the piezoelectric element being mounted on a bottom surface of the recessed portion; and The temperature sensing element has a portion located closer to an upper end side of the recess than the piezoelectric element. 2. The piezoelectric device according to claim 1, wherein: A cover body is also provided for sealing the recessed portion. 3. The piezoelectric device according to claim 2, wherein: The temperature sensing element includes a temperature sensing film overlapping with a surface of the cover body on the mounting base side. 4. The piezoelectric device according to claim 3, wherein: The temperature sensitive film has a portion overlapping with the recessed portion in a plan perspective view. 5. The piezoelectric device according to claim 3 or 4, wherein: The temperature sensitive film has a portion located outside the recessed portion in a plan perspective view. 6. The piezoelectric device according to claim 2, wherein: The temperature sensing element is a chip-type element mounted on a surface of the cover body on the mounting base side. 7. The piezoelectric device according to claim 2, wherein: The temperature sensing element is a chip-type element mounted on a wall portion of the recess. 8. The piezoelectric device according to claim 1, wherein: The temperature sensing element hermetically seals the recess. 9. The piezoelectric device according to claim 8, wherein: The temperature sensing element is a chip-type element. 10. The piezoelectric device according to claim 8 or 9, wherein: The temperature sensing element and the mounting base do not abut against each other in a direction along the bottom surface of the recessed portion. 11. The piezoelectric device according to claim 8 or 9, wherein: The temperature sensing element has a portion embedded in an upper end of the recess. 12. The piezoelectric device according to claim 8 or 9, wherein: The temperature sensing element has a portion surrounding the upper end of the mounting base from the outer peripheral side. 13. The piezoelectric device according to any one of claims 8 to 12, wherein: The temperature sensing element has: a component body; and Two component terminals, exposed to the outside of the component body, The mounting base has: a substrate portion having a bottom surface of the recessed portion; a frame portion having an inner peripheral surface of the recessed portion; and Two connecting electrodes are located at the upper end of the frame and are connected to the two element terminals. The element body and the upper end of the frame portion are joined to each other in a sealing area extending in an annular shape along the upper end of the frame portion. At least one of the two connection electrodes is located on the inner peripheral side of the sealing area. 14. The piezoelectric device according to any one of claims 8 to 13, wherein: The temperature sensing element has: a component body; and Two component terminals, exposed to the outside of the component body, The mounting base has: a substrate portion having a bottom surface of the recessed portion; a frame portion having an inner peripheral surface of the recessed portion; and Two connecting electrodes are located at the upper end of the frame and are connected to the two element terminals. The element body and the upper end of the frame portion are joined to each other in a sealing area extending in an annular shape along the upper end of the frame portion. At least one of the two connection electrodes is located on the outer peripheral side of the sealing region. 15. The piezoelectric device according to any one of claims 8 to 14, wherein: The temperature sensing element has: a component body; and Two component terminals, exposed to the outside of the component body, The mounting base has: a substrate portion having a bottom surface of the recessed portion; a frame portion having an inner peripheral surface of the recessed portion; two connecting electrodes, located at the upper end of the frame portion, and connected to the two element terminals; and The metal layer for sealing is located at the upper end of the frame, extends along the upper end of the frame and is annular, and is bonded to the element body. One of the two connection electrodes is connected to the metal layer at the upper end of the frame portion.