JP4905859B2 - Piezoelectric device and method for manufacturing piezoelectric device - Google Patents

Description

  The present invention relates to a piezoelectric device and a method for manufacturing the piezoelectric device, and more particularly to a piezoelectric device having a package having a sealing hole in a package bottom plate as a component and a method for sealing the sealing hole.

  Conventionally, as shown in FIG. 13, with respect to a package 3 that accommodates a piezoelectric vibrating piece 2, a piezoelectric device 1 that requires vacuum sealing or sealing with an inert gas uses a tuning fork type piezoelectric vibrating piece. . Such a piezoelectric device 1 employs a structure in which the bottom plate of the package 3 has two layers and a step hole (sealing hole) 4 is formed in the bottom plate. The sealing hole formed in the package 3 is normally closed by melting the solder ball 5, but there are the following problems when the sealing hole 4 has one stage. That is, when the solder ball 5 is smaller than the sealing hole 4, the solder ball 5 falls into the package 3 through the sealing hole 4, or the solder ball 5 is sealed in the sealing hole 4. If it is larger than 4, the amount of solder that protrudes from the sealing hole 4 when the solder ball 5 is melted increases, and it is difficult to position the solder ball 5 before melting.

In order to solve such problems and reduce the height, a piezoelectric device having a single package bottom plate is disclosed in Patent Document 1. As shown in FIG. 14, the piezoelectric device 1 disclosed in Patent Document 1 is formed so that a sealing hole 4 is overlapped with a part of a frame constituting the side wall of the package 3a on the bottom plate of the package 3a. It is characterized by doing. With such a configuration, a part of the opening of the sealing hole 4 located on the cavity side of the package 3a is blocked by the end face of the frame. For this reason, when the solder ball 5 is thrown into the sealing hole 4, the edge part of a frame will play the role of a step part.
JP 2004-320150 A

  If it is a piezoelectric device of the structure currently disclosed by patent document 1, even if it is a case where a baseplate is made into one layer, it can perform easily sealing a sealing hole using a solder ball. However, the following problems remain in the piezoelectric device configured as described above.

  That is, in the piezoelectric device configured as disclosed in Patent Document 1, the sealing hole needs to be provided from the outer periphery of the package. For this reason, in the sealing hole formation part, the joint surface between a frame and a baseplate becomes small. Further, since the substrate strength also deteriorates, cracks may occur when mechanical stress is applied, and the hermetic sealing state may not be maintained. In addition, when the frame is a metal or has a low profile, the sealing member can be used for a frame with good wettability, a metal film or a seam ring disposed between the frame and the lid, etc. There is a possibility that a sufficient amount of solder cannot be secured in the sealing hole.

  Therefore, in the present invention, the bonding strength between the bottom plate and the frame body in the package is sufficiently maintained, and even when the bottom plate is a single layer, sealing using a solder ball is possible, and the height can be reduced. An object of the present invention is to provide a piezoelectric device that can be used and a method for manufacturing the piezoelectric device.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.
A piezoelectric device according to a first aspect includes a piezoelectric vibrating piece and a package that accommodates the piezoelectric vibrating piece. The bottom plate of the package includes a through hole for hermetic sealing, and the through hole has a solid seal. A piezoelectric device in which the through hole is sealed with the sealing material cured after the material is disposed and melted, and when the solid sealing material is disposed in the through hole, In order to prevent the sealing material from entering the cavity of the package by the sealing material coming into contact with a part of the piezoelectric vibrating piece, the through hole has the piezoelectric vibration housed in the package. When the piece is viewed in plan, at least a part of the piezoelectric vibrating piece overlaps, the input / output electrode or the extraction electrode of the piezoelectric vibrating piece is not formed at the contact position of the sealing material, and the contact position is The vibration area of the piezoelectric vibrating piece is not The piezoelectric device according to claim.
In the piezoelectric device according to the second aspect, the piezoelectric vibrating piece includes at least a vibrating portion including an excitation electrode, an arm portion including an input / output electrode, and an extraction electrode connecting the excitation electrode and the input / output electrode. The piezoelectric device according to the first aspect, wherein the through hole overlaps the arm portion.
The piezoelectric device according to a third aspect is the piezoelectric device according to the second aspect, in which the through hole overlaps with a position located on a tip side of a position where the input / output electrode is formed in the arm portion. Piezoelectric device.
In the piezoelectric device according to a fourth aspect, the through hole overlaps with the position of the arm portion located between the input / output electrode and an electrode formed on the distal end side of the arm portion with respect to the input / output electrode. The piezoelectric device according to the second embodiment, which is characterized in that
The piezoelectric device according to any one of the second to fourth embodiments, wherein the piezoelectric device according to a fifth aspect includes two arm portions with respect to one vibrating portion.
The piezoelectric device according to any one of the second to fifth embodiments, wherein the arm device has a metal coating at a position facing the through-hole in the arm portion.
A piezoelectric device according to a seventh aspect includes a piezoelectric vibrating piece and a package that accommodates the piezoelectric vibrating piece. The piezoelectric device includes a through hole in a bottom plate of the package and seals the through hole with a sealing material. The through hole is a position where at least a part thereof overlaps when the piezoelectric vibrating piece accommodated in the package is viewed in plan, and the input / output electrode, the extraction electrode, and the vibration region of the piezoelectric vibrating piece A piezoelectric device characterized in that the distance from the opening surface of the through hole to the piezoelectric vibrating piece is not more than half of the diameter of the largest inscribed circle of the through hole.
The piezoelectric device according to any one of the first to seventh aspects, wherein the piezoelectric device according to an eighth aspect is one in which the piezoelectric vibrating piece vibrates flexibly.
The piezoelectric device manufacturing method according to the ninth aspect is a method for manufacturing a piezoelectric device that seals a cavity inside the package by melting and curing a solid sealing material in a through hole formed in the package. Then, the solid sealing material disposed inside the sealing hole is brought into contact with a part of the piezoelectric vibrating piece disposed in the cavity to prevent the sealing material from falling into the cavity, and then the sealing material is sealed. A method for manufacturing a piezoelectric device, comprising melting and curing a stopper.
Moreover, the application example for achieving the said objective is as follows.
A piezoelectric device according to the present invention includes a piezoelectric vibrating piece and a package that accommodates the piezoelectric vibrating piece. The bottom plate of the package includes a through hole for hermetic sealing, and melts a solid sealing material. A piezoelectric device that seals the through-hole by curing the sealing material later, wherein the through-hole overlaps when the piezoelectric vibrating piece accommodated in the package is viewed in plan view When the solid sealing material is disposed in the through hole, the sealing material comes into contact with a part of the piezoelectric vibrating piece, so that the sealing material is inside the cavity of the package. It is characterized by having a configuration for preventing intrusion. According to the piezoelectric device having such a feature, even when the bottom plate is a single layer, it is possible to perform sealing using solder balls. Further, since the area of the bonding surface between the frame body and the bottom plate constituting the package base is not changed by the formation of the sealing hole, the bonding strength between the bottom plate and the frame body can be sufficiently maintained. Furthermore, since the bottom plate can be a single layer, the overall height of the piezoelectric device can be reduced.

  In the piezoelectric device having the characteristics as described above, the piezoelectric vibrating piece connects at least a vibrating portion including an excitation electrode, an arm portion including an input / output electrode, and the excitation electrode and the input / output electrode. It is preferable that the sealing hole is formed below the arm portion. According to such a configuration, the solder ball as the sealing material comes into contact with the arm portion. Therefore, the excitation electrode, the input / output electrode, the extraction electrode, and the like are not contaminated by the contact of the sealing material, and it is possible to prevent the oscillation characteristics from being adversely affected.

  In the piezoelectric device having the above-described characteristics, the through hole may be provided so as to correspond to a position located on the tip side of the arm portion where the input / output electrode is formed. With such a configuration, there is no possibility that the balance of the fixed state of the piezoelectric vibrating piece is lost due to the adhesion of the sealing material.

  In the piezoelectric device having the above-described characteristics, the through hole is located between the input / output electrode formed in the arm portion and an electrode formed on the distal end side of the arm portion with respect to the input / output electrode. It can also be provided corresponding to the location to be performed. Even if it is a case where it is set as such a form, it becomes possible to keep the balance of the fixed state of a piezoelectric vibrating piece similarly to the above.

  Further, it is desirable that two arm portions are formed for one vibration portion. By providing two arms with respect to one vibration part and setting them as target forms, the balance when fixing (supporting) the piezoelectric vibrating piece is stabilized.

  Further, a metal film can be formed on the arm portion at a position corresponding to the through hole when the arm portion is arranged in the package. With such a configuration, it is possible to obtain new effects such as prevention of removal of the sealing material and stabilization of the fixed state of the piezoelectric vibrating piece.

  The through hole is formed at a position where at least a part thereof overlaps when the piezoelectric vibrating piece accommodated in the package is viewed in plan, and the distance from the opening surface of the through hole to the piezoelectric vibrating piece is a through hole. It is desirable that the inscribed circle is configured to be less than half the diameter of the largest inscribed circle. With such a configuration, the sealing material can be prevented from rolling into the package when sealing the through hole.

  Further, the quartz base plate may have a cut angle that excites bending vibration. Since the tuning fork type piezoelectric vibrating piece as the piezoelectric vibrating piece for exciting the bending vibration can separate the vibrating portion and the supporting portion, it is possible to meet the demand for further downsizing of the piezoelectric device.

  In addition, the piezoelectric device manufacturing method according to the present invention for achieving the above object seals the cavity inside the package by melting and curing a solid sealing material for the through-hole formed in the package. A method for manufacturing a piezoelectric device, comprising: bringing a solid sealing material arranged inside a sealing hole into contact with a part of a piezoelectric vibrating piece arranged in the cavity, and dropping the sealing material into the cavity After preventing this, the sealing material is melted and cured. According to such a method of manufacturing a piezoelectric device, even when the bottom plate of the package is a single layer, the sealing material does not enter the cavity of the package.

Hereinafter, embodiments of a piezoelectric device and a method for manufacturing the piezoelectric device of the present invention will be described in detail with reference to the drawings.
First, a first embodiment of the piezoelectric device of the present invention will be described with reference to FIGS. 1A is a plan view showing the structure of the piezoelectric device with the lid removed, and FIG. 1B is a view showing a cross section AA in FIG. Moreover, FIG. 2 is a figure which shows the variation of the form of a sealing hole, and FIG. 3 is a reference perspective view at the time of disassembling a piezoelectric device.

The piezoelectric device 10 according to the present embodiment is a piezoelectric vibrator configured based on a piezoelectric vibrating piece 30 and a package 12 that accommodates the piezoelectric vibrating piece 30.
The piezoelectric vibrating piece 30 is not particularly limited in its vibration form, but preferably has the following structure. That is, it has a structure having a vibrating portion 32 and arm portions 34 a and 34 b extending from the vibrating portion 32.

  The piezoelectric vibrating piece 30 shown in FIG. 1 excites thickness-shear vibration, and specifically, an AT-cut quartz base plate is used as a raw material. In such a piezoelectric vibrating piece 30, the excitation electrode 36a, 36b is connected to the vibration part 32, the input / output electrodes 40a, 40b are connected to the arm parts 34a, 34b, and the extraction electrode 36a, 36b is connected to the input / output electrodes 40a, 40b. Electrodes 38a and 38b are formed. Here, it is desirable that the input / output electrodes 40a and 40b are formed slightly inside (the base side of the arm portion) from the tips of the arm portions 34a and 34b.

  The package 12 includes a package base 14 having a cavity for accommodating the piezoelectric vibrating piece 30 described above, and a lid 16 that is a lid for sealing an upper opening in the package base 14.

  The package base 14 is a box configured by laminating and firing at least a bottom plate 14b formed of a ceramic sheet and a frame 14a. The bottom plate 14b is hermetically sealed with the package 12 after the top opening is sealed by the lid 16 in a state where the inside of the cavity is vacuumed or the gas inside the cavity is replaced with an inert gas. A through hole to be used (hereinafter referred to as a sealing hole 24) is formed. A mount electrode 18 and a wiring pattern (not shown) are formed on the surface inside the cavity of the bottom plate 14b. A mounting electrode 20 is formed on the outer surface of the bottom plate 14 b, that is, on the bottom surface of the package 12.

  The sealing hole 24 is located in the vicinity of the mount electrode 18, more specifically, when the piezoelectric vibrating piece 30 is mounted, the tip corresponding position in the arm portion 34 a (or the arm portion 34 b), and the mount electrode It forms in a position corresponding to between 18 formation positions. That is, when the bottom plate 14 b and the piezoelectric vibrating piece 30 are viewed in plan, at least a part of the sealing hole 24 overlaps the arm portion 34 a (or the arm portion 34 b) in the piezoelectric vibrating piece 30.

  Further, the sealing hole 24 in this embodiment is provided with a metal film (metallized) 26 on the inner peripheral surface thereof, and the wettability when the solder ball as the sealing material 28 is melted is enhanced. . A solder ball is a solder formed in a spherical shape. After being accommodated in the sealing hole 24, the solder ball is melted by irradiation with a laser or the like, or simply heated, and cured by cooling to be sealed. The hole 24 is blocked.

  The lid 16 is a flat plate made of metal, glass, or the like whose linear expansion coefficient approximates that of the package base 14 described above. Specifically, the constituent members of the lid 16 in the case where the package base 14 is made of ceramics can include Kovar and soda glass. When the lid 16 is made of metal, seam welding is performed by interposing a metal ring called a seam ring (not shown) between the package base 14 and the lid 16, or Au—Sn, Au It is common to seal using a metal brazing material such as -Ge. When the lid 16 is made of glass, the lid 16 is generally welded to the package base 14 using low melting point glass.

  Here, about the sealing hole 24, the shape of the opening part is shown in FIG. 1 so that it may be circular. However, the shape of the opening of the sealing hole 24 may be as shown in FIGS. In addition, the size of the sealing hole 24 is defined as b where the distance between the inner wall surfaces facing the sealing hole 24 is the smallest (the diameter of the inscribed circle of the sealing hole 24 is the largest), and b It is determined to be larger than the dimension a between the arm portion 34a. That is, the largest solder ball constituting the sealing material 28 that can be put into the sealing hole 24 has a diameter of b, and a is a range of half or less of b and a radius size or less (0 <a ≦ b / 2) is desirable.

  Next, a method for manufacturing a piezoelectric device having the above structure will be described with reference to FIG. First, a conductive adhesive 22 as an adhesive member is applied to the mount electrode 18 in the package base 14 (see FIG. 4A). Next, the piezoelectric vibrating piece 30 is mounted so that the input / output electrodes 40a and (40b) of the piezoelectric vibrating piece 30 are disposed on the applied conductive adhesive 22 (see FIG. 4B). After the conductive adhesive 22 is cured, the lid 16 is disposed in the upper opening of the package base 14 that accommodates the piezoelectric vibrating piece 30, and the upper opening is sealed (see FIG. 4C).

  Next, the package 12 is inverted so that the bottom plate 14b of the package base 14 is exposed on the upper surface side in the mounted state. In this state, a sealing material (solder ball) 28 is disposed in the sealing hole 24 formed in the bottom plate 14b (see FIG. 4D). The package 12 in which the sealing material 28 is disposed is put into a vacuum chamber or the like, and the cavity of the package 12 is evacuated or the gas existing in the cavity of the package 12 is replaced. After evacuating the cavity or replacing the gas, the sealing material 28 disposed in the sealing hole 24 is irradiated with a laser, etc., and the sealing material 28 is melted and then cooled and cured. Then, the sealing hole 24 is closed (see FIG. 4E).

  According to the piezoelectric device 10 configured as described above, even if the bottom plate 14b of the package base 14 is a single layer, the sealing hole 24 can be sealed using a solder ball. Further, in the configuration as described above, the frame body 14a is joined to the bottom plate 14b over the entire circumference, so that the strength of the package 12 is not deteriorated. In addition, since the bottom plate 14a of the package base 14 can be a single layer, the overall height of the piezoelectric device 10 can be reduced.

  Further, by defining the relationship between “a” related to the size of the sealing hole 24 and “b” related to the size of the solder ball, which is the sealing material 28, as shown in FIG. When the material 28 is introduced into the sealing hole 24 and the sealing material 28 is in contact with the arm portion 34a, the position of the maximum width (solder ball diameter) of the sealing material 28 is within the sealing hole 24. It will be in the state that existed.

  Accordingly, since the distance between the sealing material 28 and the metal coating 26 on the inner wall surface of the sealing hole 24 is reliably kept short, the sealing material 24 is likely to adhere to the metal coating 26 when melted. The sealing hole 24 can be sealed.

  Further, as described above, the contact position of the sealing material 28 is outside the region of the input / output electrodes 40a and 40b and the extraction electrodes 38a and 38b of the arm 34a in the piezoelectric vibrating piece 30 so as to be the exposed surface of the piezoelectric substrate, for example. By forming the sealing hole 24 in the electrode, it is possible to prevent electrode peeling and contamination of the piezoelectric vibrating piece 30. In addition, by bringing the sealing material 28 into contact with the arm portion 34a away from the vibration region, even if the arm portion 34a is contaminated, the characteristics as a vibrator are not affected. Furthermore, the possibility that the molten gas of the sealing material 28 adheres to the vibration region is low.

  Here, in the above embodiment, the arm portion 34a is shown to be flat. However, as shown in FIG. 5, a convex portion 35 may be formed on the arm portion 34a. With such a configuration, the solder ball as the sealing material 28 can be fastened to the inside of the sealing hole 24. Further, with such a configuration, there is no possibility that the sealing material 28 rolls into the cavity even when the mounting state of the piezoelectric vibrating piece 30 is inclined.

  Moreover, since the convex part 35 is formed in the arm part 34a away from the vibration area, it is difficult to adversely affect the reflection of vibration energy. Moreover, since the convex part 35 can be formed by the etching at the time of forming the external shape of the piezoelectric vibrating piece 30, there is little burden on a processing process.

  Next, a second embodiment of the piezoelectric device of the present invention will be described with reference to FIG. 6A is a cross-sectional view showing a state where a solder ball as a sealing material is placed, and FIG. 6B is a cross-sectional view showing a state after sealing.

  Most of the configuration of the piezoelectric device according to the present embodiment is the same as that of the piezoelectric device 10 according to the first embodiment. Accordingly, parts having the same function are denoted by reference numerals obtained by adding 100 to the reference numerals in FIG. 1 and detailed description thereof will be omitted.

  The characteristic part of the piezoelectric device 110 according to the present embodiment is in the arm part 134 a of the piezoelectric vibrating piece 130. Specifically, the metal coating 137 is formed at a location where the sealing material 128 placed in the sealing hole 124 formed in the package base 114 contacts the arm portion 134a.

  Thus, the wettability of the arm part 134a improves by forming the metal film 137 in the contact part in the arm part 134a. For this reason, the sealing material (solder in the embodiment) 128 melted by the laser or heating adheres to the metal coating 137 without being repelled by the crystal. Therefore, the sealing material 128 is cured in such a way as to connect the sealing hole 124 and the piezoelectric vibrating piece 130.

  When the sealing material 128 adopts such a configuration, the probability that the sealing material 128 falls out of the sealing hole 124 decreases. In addition, since the piezoelectric vibrating piece 130 is fixed by the sealing material 128, the piezoelectric vibrating piece 130 can be stabilized.

  Next, an application form of the piezoelectric device 110 according to the embodiment will be described with reference to FIG. 7A is a cross-sectional view showing a state where a solder ball as a sealing material is placed, and FIG. 7B is a cross-sectional view showing a state after sealing.

  In the piezoelectric device 110 having the form shown in FIG. 7, the metal coating 126 formed on the inner peripheral surface thereof to improve the wettability of the sealing hole 124 is also formed around the cavity side opening. The metal coating 126a is different from the embodiment shown in FIG.

  With such a configuration, the sealing material 128 spreads wet around the cavity side opening, that is, the portion where the opening metal film 126a is disposed. For this reason, an anchor effect works and it becomes difficult for the sealing material 128 to come out of the sealing hole 124. In addition, since the bonding area between the package base 114 and the sealing material 128 is increased, sealing reliability is also increased.

  Next, a third embodiment of the piezoelectric device of the present invention will be described with reference to FIG. 8A is a perspective view showing the form of the piezoelectric vibrating piece, and FIG. 8B is a front sectional view showing the structure of the piezoelectric device.

  The piezoelectric device according to this embodiment is almost the same in configuration as the piezoelectric device 10 according to the first embodiment described above. Therefore, the parts having the same functions are denoted by the reference numerals in FIG. 1 plus 200, and detailed description of the mount electrodes, the input / output electrodes and the like is omitted.

  A characteristic part of the piezoelectric device 210 according to the present embodiment is the piezoelectric vibrating piece 230. Specifically, the base plate of the part constituting the vibration part 232 is thinner than the arm parts 234a and 234b and the base part 231. With such a configuration, it is possible to increase the oscillation frequency while maintaining the mechanical strength at the support portion. In addition, according to the piezoelectric vibrating piece 130 having such a configuration, it is possible to take a form in which a part of the sealing hole 224 is closed by the arm portion 234a, and thus it is possible to completely prevent the sealing material 228 from rolling into the cavity. It becomes possible. In addition, about another structure, an effect | action, and an effect, it is the same as that of the 1st, 2nd embodiment mentioned above.

  Next, a fourth embodiment according to the piezoelectric device of the present invention will be described with reference to FIG. In the piezoelectric device 310 according to the present embodiment, a tuning fork-type piezoelectric vibrating piece 330 is configured by a piezoelectric element plate that excites bending vibration. Specifically, two bending arms 332a and 332b constituting the vibrating portion 332, a base portion 331 that supports the bending arms 332a and 332b, and the base portion 331, and the bending arms 332a and 332b and the base portion 331 are extended. Have two arm portions 334a and 334b. Excitation electrodes (not shown) are formed on the bending arms 332a and 332b, and input / output electrodes 340a and 340b are formed on the arm portions 334a and 334b, respectively. The excitation electrodes and the input / output electrodes 340a and 340b are not shown. Not connected by an extraction electrode.

  The piezoelectric device 310 according to the present embodiment is the same as the piezoelectric device according to the first to third embodiments described above with respect to the constituent elements other than the piezoelectric vibrating piece. Therefore, the same reference numerals in FIG. 1 plus 300 are attached to the parts having similar functions, and the detailed description thereof is omitted.

  As shown in FIG. 9, the piezoelectric vibrating piece 330 according to the present embodiment has dummy electrode forming portions 319, 306, 340, 340 b closer to the distal end side of the arm portions 334 a, 334 b than the input / output electrodes 340 a, 340 b provided on the arm portions 334 a, 334 b. 319. Then, the input / output electrodes 340 a and 340 b are mounted on the mount electrodes 318 and 318, and an adhesive (conductive adhesive or the like) is applied to the dummy electrode forming portions 319 and 319 to be fixed to the bottom plate 314 b of the package base 314. Thus, the mounting state of the piezoelectric vibrating piece 330 can be stabilized.

  Further, the sealing hole 324 is formed at a corresponding position between the input / output electrodes 340a and 340b and the dummy electrode forming portions 319 and 319 in at least one of the arm portions 334a and 334b. Even with such a configuration, a piezoelectric device similar to that of the above embodiment can be obtained. It should be noted that it is desirable to form a metal film (not shown) at the dummy electrode forming locations 319 and 319 and to form a metal film also at a corresponding location of the bottom plate 314b in the package base 314.

  Next, a modification of the fourth embodiment will be described with reference to FIG. In the piezoelectric device 310 according to the present embodiment, the sealing hole 324 is formed in the bottom plate 314b at a position corresponding to one of the dummy electrode forming portions 319 and 319 in the arm portions 334a and 334b of the piezoelectric vibrating piece 330 shown in FIG. Forming. Thus, the fixed state can be balanced by making the position of the sealing hole 324 correspond to the dummy electrode forming portion 319. In addition, when taking such a form, it is necessary to form the metal film as a dummy electrode in the arm part 334a. This is because the melted sealing material adheres to the arm portion 334a.

  In any of the piezoelectric devices according to the above-described embodiments, two arm portions extending from the vibrating portion (including the base portion) are illustrated. However, the arm portion formed on the piezoelectric vibrating piece may be provided with two input / output electrodes 340a and 340b on one arm 334 as shown in FIG. In this case, an extraction electrode (not shown) that connects the excitation electrode (not shown) and the input / output electrodes 240a and 340b is disposed on both the front and back surfaces of the arm 334 to prevent a short circuit therebetween. It is desirable to do.

  Moreover, in any of the above-described embodiments, the piezoelectric vibrating piece is provided with an arm portion. However, the piezoelectric device of the present invention also includes a piezoelectric device 10 having a form as shown in FIG. That is, in the bottom plate 14 b of the package base 14, the sealing hole 24 is formed at a location corresponding to the base portion 31 that does not contribute to excitation of the piezoelectric vibrating piece 30. Even in the piezoelectric device 10 having such a structure, the sealing material placed in the sealing hole 24 contacts a part of the piezoelectric vibrating piece 30 and does not enter the cavity of the package. Therefore, it can be said that it is a piezoelectric device according to the present invention.

Furthermore, the present invention has been described by taking as an example a piezoelectric device using a piezoelectric vibrating piece that excites thickness shear vibration as the first embodiment, the second embodiment, and the third embodiment. For example, a tuning fork type piezoelectric device using a resonator element may be used.
In addition, this invention has the following advantages by the fixed location which fixed the input-output electrode and the mount electrode between the vibration part of a piezoelectric device, and the position corresponding to a sealing hole.

The configuration of the first embodiment will be described as an example.
When the sealing hole 24 is sealed, the sealing material 28 rarely comes into contact with the arm portion 34a, or gas from the sealing material 28 is blown out and adheres to the arm portion 34a due to melting. There is a possibility that the transfer characteristic of the vibration energy of the arm part 34a may change.

  However, in the case of the present invention, since there is the above-mentioned fixed portion that functions as a high impedance with respect to vibration energy between the vibration portion and the sealing hole, vibration energy due to contact between the arm portion 34a and the sealing material 28 or the like The influence of impedance changes (changes in transfer characteristics) on can be ignored.

Therefore, even if a piezoelectric device in which the sealing material 28 and the arm portion 34 a are in contact with a non-contact piezoelectric device is mixed due to manufacturing variations in the process of sealing the sealing hole 24, there is a difference in quality among individuals. hard.
Such a function is particularly effective for a piezoelectric device using a piezoelectric vibrating piece that bends and vibrates, such as those used in tuning fork type piezoelectric devices and other gyro sensors.

  That is, for example, in the case of a tuning fork type piezoelectric device, in order for the two bending arms to bend and vibrate symmetrically within the surface of the piezoelectric substrate, the vibration performance is symmetric with respect to the center line in the direction in which the two bending arms are arranged. Must be set to

Therefore, according to the above-described function, even if the sealing material 28 contacts the arm portion 34a, the impedance with respect to the vibration energy of the arm portion 34a does not fluctuate greatly. The vibration characteristics of the tuning fork type piezoelectric device are not deviated from the standard value.
In addition, although this invention was demonstrated using the solder material as a sealing material, this invention is not limited to this, It consists of a sealing material which consists of soft solder materials other than solder, silver, gold tin, etc. A brazing material may be used as a sealing material.

It is a figure which shows the structure of the piezoelectric device which concerns on 1st Embodiment. It is a figure which shows the form example of the sealing hole of the piezoelectric device which concerns on embodiment. It is a reference perspective view which shows the structure of the piezoelectric device which concerns on 1st Embodiment. It is a figure which shows the manufacturing process of a piezoelectric device. It is a figure which shows the application form of the piezoelectric device which concerns on 1st Embodiment. It is a figure which shows the structure of the piezoelectric device which concerns on 2nd Embodiment. It is a figure which shows the application form of the piezoelectric device which concerns on 2nd Embodiment. It is a figure which shows the structure of the piezoelectric device which concerns on 3rd Embodiment. It is a figure which shows the structure of the piezoelectric device which concerns on 4th Embodiment. It is a figure which shows the form which covers the piezoelectric device which concerns on 4th Embodiment. It is a figure which shows the example of the piezoelectric device which has a piezoelectric vibrating piece which used one arm part. It is a figure which shows the example of the piezoelectric device which has a piezoelectric vibrating piece which does not have an arm part. It is a figure which shows the structure of the conventional piezoelectric device. It is a figure which shows the structure of the conventional piezoelectric device which made the bottom plate of the package 1 layer.

Explanation of symbols

  10 ......... Piezoelectric device, 12 ......... Package, 14 ......... Package base, 14a ......... Frame, 14b ......... Bottom plate, 16 ......... Lid, 18 ......... Mount electrode, 20 ......... Mounting electrode, 22 ......... conductive adhesive, 24 ......... sealing hole, 26 ......... metal coating, 28 ......... sealing material, 30 ......... piezoelectric vibrating piece, 32 ......... vibrating part, 34a, 34b ......... arm, 36a, 36b ... excitation electrode, 38a, 38b ... extraction electrode, 40a, 40b ... input / output electrode.

Claims (9)

A piezoelectric vibration piece and a package for housing the piezoelectric vibration piece, and a bottom plate of the package is provided with a through hole for hermetic sealing, and a solid sealing material is disposed in the through hole and melted. A piezoelectric device in which the through hole is sealed with the cured sealing material ,
Said solid shaped sealing material when disposed in the through hole, by which the sealing material is in contact with a portion of the piezoelectric resonator element, that the sealing material from entering inside the cavity of the package In order to prevent the through-hole, when the piezoelectric vibrating piece housed in the package is viewed in plan, the through-hole is at least partially overlapped with the piezoelectric vibrating piece, and the piezoelectric vibration piece is located at the contact position of the sealing material. A piezoelectric device characterized in that no input / output electrode or extraction electrode is formed, and the contact position is not a vibration region of the piezoelectric vibrating piece . The piezoelectric vibrating piece includes at least a vibrating portion including an excitation electrode, an arm portion including an input / output electrode, and an extraction electrode connecting the excitation electrode and the input / output electrode, and the through hole includes the arm. The piezoelectric device according to claim 1, wherein the piezoelectric device overlaps a portion. 3. The piezoelectric device according to claim 2, wherein the through hole overlaps with a position located on a tip side of a position where the input / output electrode is formed in the arm portion. The said through-hole overlaps with the location of the said arm part located between the said input / output electrode and the electrode formed in the front end side of the arm part rather than the said input / output electrode. The piezoelectric device described. The arm portion, the piezoelectric device according to any one of claims 2 to 4, characterized in that the two relative one vibrating portion. Wherein the arm portion, the piezoelectric device according to any one of claims 2 to 5, characterized in that at a position facing the through-hole, there is a metal coating. A piezoelectric device having a piezoelectric vibrating piece and a package containing the piezoelectric vibrating piece, including a through hole in a bottom plate of the package, and sealing the through hole with a sealing material;
The through hole is a position where at least part of the through hole overlaps when the piezoelectric vibrating piece accommodated in the package is viewed in plan , and does not overlap the input / output electrode, the extraction electrode, and the vibration region of the piezoelectric vibrating piece. to have, a piezoelectric device, wherein the distance from the opening surface of the through hole to the piezoelectric vibrating piece is less than half the diameter of the largest ones of the inscribed circle of the through hole.   The piezoelectric device according to claim 1, wherein the piezoelectric vibrating piece performs bending vibration. A method of manufacturing a piezoelectric device for sealing a cavity inside the package by melting and curing a solid sealing material for a through-hole formed in the package,
After contacting the solid sealing material disposed inside the sealing hole with a part of the piezoelectric vibrating piece disposed in the cavity, and preventing the sealing material from falling into the cavity,
A method for manufacturing a piezoelectric device, comprising melting and curing the sealing material.

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