JP4692619B2 - Quartz vibrating piece, manufacturing method thereof, quartz crystal device using quartz crystal vibrating piece, mobile phone device using quartz crystal device, and electronic equipment using quartz crystal device - Google Patents

Description

The present invention relates to a crystal resonator element, a method for manufacturing the same, a crystal device in which the crystal oscillator piece is accommodated in a package, and a mobile phone and an electronic apparatus using the crystal device.

Quartz that contains a crystal resonator element in a small information device such as a hard disk drive (HDD), mobile computer, or IC card, or mobile communication device such as a mobile phone, a car phone, or a paging system Crystal devices such as vibrators and crystal oscillators are widely used.
FIG. 13 is a schematic perspective view showing a known configuration example of a crystal vibrating piece used in such a crystal device, and FIG. 14 is an end view taken along line AA in FIG. 13 (see Patent Document 1). ).

In these figures, the quartz crystal vibrating piece 3 is formed by cutting out from, for example, a single crystal of quartz and processing it into a tuning fork type. At this time, it is cut out from a single crystal of crystal so that the X axis shown in FIG. 13 is an electric axis, the Y axis is a mechanical axis, and the Z axis is an optical axis.
Further, when cutting from a single crystal of quartz, in the orthogonal coordinate system composed of the X-axis, Y-axis, and Z-axis described above, the XY plane composed of the X-axis and the Y-axis is about 1 degree counterclockwise around the X-axis. It is tilted by 5 degrees.
The shape shown in the figure is formed by etching a substrate (described later) made of such a quartz material. In this case, the quartz crystal vibrating piece 3 is configured by a tuning fork type crystal piece including a base portion 5 and a pair of vibrating arms 6 and 7 extending in parallel from the base portion 5.

The base portion 5 of the crystal vibrating piece 3 is fixed to a package-side electrode portion (not shown).
Grooves 9 and 10 extending in the length direction are formed in the vibrating arms 6 and 7, respectively, and excitation electrodes 11 and 12 are formed on the surfaces of the vibrating arms 6 and 7. This excitation electrode 11,1
2 by applying a driving voltage from the outside to the vibrating arms 6, 7.
It vibrates so that a approaches and separates from each other. By taking out the vibration frequency based on such vibration, it is used for various signals such as a clock signal for control.

JP 2002-76806 A

By the way, as shown in FIG. 14, the crystal vibrating piece 3 having such a structure has grooves 9, 9, 10, and 10 formed on the upper and lower surfaces of the vibrating arms 6 and 7, respectively. Groove 9, 9, 10
, 10 are provided with excitation electrodes 11 and 12 to improve electric field efficiency and to obtain excellent vibration performance.
In order to form the quartz crystal resonator element 3 having such a shape, the outer shape thereof is formed by etching quartz, and the grooves 9, 9, 10, 10 of the vibrating arms 6, 7 are further etched by half etching. A forming step is employed.

15 to 17 are process diagrams showing a method for manufacturing the quartz crystal vibrating piece 3. Each step is shown in the order of steps only for the region corresponding to one vibrating arm 6 among the cut surfaces of the vibrating arms 6 and 7 in FIG. 14 described above. It is a progression.

As shown in FIG. 15A, a substrate 13 made of a quartz material is prepared, and as shown in FIG. 15B, a corrosion-resistant film is formed on the surface (front and back surfaces) of the substrate 13 by a technique such as sputtering or vapor deposition. 14 is formed. The corrosion-resistant film 14 is composed of, for example, a chromium layer as a base layer and a gold coating layer coated thereon.
In the following steps, since the same processing is performed on both the upper and lower surfaces in FIG. 15 of the substrate 13, only the upper surface will be described in order to avoid complexity.

Next, as shown in FIG. 15C, a resist 15 is applied on the entire surface. Then, corresponding to the outer shape of the quartz crystal vibrating piece (see the quartz crystal vibrating piece 3 in FIG. 13), for example, a mask 16 is disposed as shown in FIG. The resist 15 is exposed and removed. Subsequently, as shown in FIG. 15 (e), the exposed corrosion-resistant film 14 is formed as shown in FIG.
As shown in FIG. 16, the resist 15 is removed, and the resist 15 is peeled off as shown in FIG.
Next, as shown in FIG. 16 (h), a resist 16 for use in groove formation is applied to the front and back surfaces, and as shown in FIG. 16 (i), the portions left by etching when the groove is formed are applied. Corresponding masks 17 and 17 are arranged on the surface of the resist 16.

Next, as shown in FIG. 16J, the resist 16 is removed leaving a portion corresponding to a portion left by etching when the groove is formed. When the substrate 13 made of a quartz material is etched with a predetermined etching solution in this state, as shown in FIG. 17 (k), the deformed shape 18 projecting sideways is formed due to the anisotropy of the quartz, The outer shape of the quartz crystal vibrating piece is formed by etching. This outer shape forming etching process takes about 140 minutes.

Next, as shown in FIG. 17 (l), the corrosion-resistant film 14 at the location where the groove is to be formed is removed by etching, and as shown in FIG. 17 (m), the substrate 13 made of a quartz material is used to form the groove. Half-etch. Thereby, the groove | channel 12 is formed. This half-etching process takes about 32.5 minutes (± 5 minutes), for example.
Subsequently, as shown in FIG. 17 (n), the resist 16 and the corrosion-resistant film 14 are removed to obtain a crystal piece having an outer shape as a crystal vibrating piece. Finally, as shown in FIG. 17 (o), a grooved crystal vibrating piece is formed by providing predetermined excitation electrodes 9 and 11 on the surface.

As described above, the process for forming the grooves 9 and 12 in the conventional crystal vibrating piece 3 is as follows.
The outer shape forming etching and the half etching for forming the groove need to be performed separately, which is complicated and requires a large number of steps.

The present invention relates to a crystal resonator element that can be manufactured easily by reducing the manufacturing process by simultaneously performing the outer shape forming etching and the groove etching in manufacturing the crystal resonator element, the manufacturing method thereof, and the crystal It is an object of the present invention to provide a crystal device using a resonator element, and a mobile phone and an electronic device using the crystal device.

According to the first aspect of the present invention, the crystal as a whole is made of quartz, and includes a base and a pair of vibrating arms extending in parallel from the base, and each vibrating arm has a groove extending in the length direction. It is a manufacturing method for forming a resonator element by etching a substrate made of a quartz material, and when etching the outer shape of the crystal resonator element, at the same time as the outer shape forming etching, the groove portion of each vibrating arm, This is achieved by a method for manufacturing a quartz crystal vibrating piece in which a plurality of small grooves divided in the width direction are continuously etched in a state of being arranged in parallel along the length direction of each vibrating arm.

According to the configuration of the first aspect of the present invention, a quartz crystal resonator element having a base portion and a pair of vibrating arms extending in parallel from the base portion and having a groove portion extending in the length direction in each vibrating arm is manufactured by etching. When forming the outer shape and the groove portion of the resonator element by etching, simultaneously with the outer shape forming etching, a small groove divided in the width direction of the groove portion of each vibrating arm is along the length direction of each vibrating arm. Etching is performed so as to be continuous in a state where a plurality of the electrodes are arranged in parallel. In this case, a narrow groove is formed as each small groove by dividing in the width direction using the irregular shape that remains without being etched based on the anisotropy of quartz. For this reason, the remaining portion of the etching where the quartz material is not completely removed remains at the bottom of the small groove. That is, the anisotropy of the quartz crystal is positively utilized to form the groove bottom portion at the time of forming the small groove by the remaining portion of the etching. Thereby, without providing a troublesome half-etching process for forming a long groove-like groove as in the prior art, the outer shape of the crystal vibrating piece and the vibrating arm can be formed at the time of etching to form the outer shape of the crystal vibrating piece. Since the groove can be formed at the same time,
The manufacturing process can be greatly simplified.
Thereby, as an effect of the present invention, in manufacturing a quartz crystal vibrating piece, it is possible to realize a manufacturing method capable of facilitating the manufacturing by simultaneously performing the outer shape forming etching and the groove etching, reducing the manufacturing process. it can.

According to a second invention, in the configuration of the first invention, the thickness t of each of the vibrating arms is set to 80 μm to 13 μm.
When the thickness is 0 μm, the width A of the small groove is approximately 15 μm or less.
According to the configuration of the second invention, the thickness t is set to 8 as the thickness of a practical vibrating arm (crystal vibrating piece).
As a result of various attempts by the inventor in the case of 0 μm to 130 μm, when the width A of the small groove is set to about 15 μm or less, the necessary condition for forming a small groove that does not penetrate is satisfied regardless of the value of the length B of the small groove. be able to.

According to a third invention, in the configuration of the second invention, when the width A of the small groove exceeds 15 μm, the length B of the small groove is 250 μm or less.
According to the configuration of the third aspect of the invention, particularly when the width A of the small groove exceeds 15 μm, the small groove that does not penetrate can be formed when the length B of the small groove is 250 μm or less.

According to the fourth aspect of the present invention, the step of forming a corrosion-resistant film on the surface of the substrate made of a quartz material, the step of applying a resist on the corrosion-resistant film, the resist and the corrosion-resistant film are provided. Etching to create a mask so as to conform to the shape corresponding to the groove formed in the vibrating arm and the outer shape of the crystal vibrating piece, and to perform the outer shape forming etching, and the outer shape of the crystal vibrating piece. And forming a necessary electrode film after forming the groove portion of each vibrating arm, and in the outer shape forming etching step, masking adapted to the outer shape of the crystal vibrating piece, and each vibrating arm The etching is performed by simultaneously performing masking in a form in which a plurality of small grooves divided in the width direction are continuously arranged in parallel along the length direction of each vibrating arm. Carried out by the method for producing the quartz crystal resonator element is achieved.

According to the configuration of the fourth invention, after forming a corrosion-resistant film on the substrate surface made of a quartz material and applying a resist, in the outer shape forming etching step when the outer shape and groove portion of the quartz vibrating piece are formed by etching, Simultaneously with the outer shape forming etching, the groove portion of each vibrating arm,
The outer shape and the groove portion are simultaneously masked at the same time so that a plurality of small grooves divided in the width direction are continuous in a state of being arranged in parallel along the length direction of each vibrating arm. Particularly, the masking of the groove portion is formed so as to be suitable for forming a narrow groove divided in the width direction of the vibrating arm in order to form each small groove. As a result, a remaining portion of the etching where the quartz material is not completely removed remains at the bottom of the small groove. In other words, the anisotropy of the quartz crystal is actively used to completely etch the outer shape, and at the same time, the groove bottom when forming the small groove is formed by the remaining portion of the etching. Thereby, without providing a troublesome half-etching process for forming a long groove-like groove as in the prior art, the outer shape of the crystal vibrating piece and the vibrating arm can be formed at the time of etching to form the outer shape of the crystal vibrating piece. Since the grooves can be formed at the same time, the manufacturing process can be greatly simplified.

According to the fifth aspect of the present invention, the crystal as a whole is formed of quartz and includes a base and a pair of vibrating arms extending in parallel from the base, and each vibrating arm has a groove extending in the length direction. In the vibration piece, a plurality of small grooves divided in the width direction are formed in the groove portion of each vibration arm so as to be continuous in a state of being arranged in parallel along the length direction of each vibration arm. This is achieved by a quartz crystal resonator element.
According to the structure of 5th invention, the lattice-like structure which partitions off a several or many small groove in the said groove part of the said vibrating arm is obtained. For this reason, the lattice structure plays a role of improving the rigidity of the vibrating arm in the groove portion where the thickness of the material is reduced. Thereby, even if the vibrating arm is provided with the groove portion, it is possible to obtain a strong crystal vibrating piece that is not easily damaged.

According to a sixth aspect of the present invention, in the configuration of the fifth aspect of the invention, the small groove is inclined such that the wall portion forming the small groove gradually increases the groove depth toward substantially the center of the small groove. It is characterized by having.
According to the structure of 6th invention, the said wall part which forms a grid | lattice-like structure is provided with the said inclination, and is provided with a form which spreads in the cross section. Thereby, the vicinity of the base end of each wall portion also has a strong structure.

According to the seventh aspect of the present invention, there is provided a quartz crystal device having a quartz crystal vibrating piece accommodated in a case or a package, wherein the quartz crystal vibrating piece is entirely formed of quartz, and has a base portion and a parallel portion from the base portion. A pair of vibrating arms extending to each of the vibrating arms, each having a groove extending in the length direction.
And in the groove portion of each vibrating arm, a small groove divided in the width direction is formed so as to be continuous in a state where a plurality of small grooves are arranged in parallel along the length direction of each vibrating arm. Achieved.
According to the configuration of the seventh aspect of the invention, the quartz crystal resonator element has a lattice-like or frame-like structure that partitions a plurality or a plurality of small grooves vertically and horizontally in the groove portion of the vibrating arm. In the thinned groove portion, the lattice structure plays a role of improving the rigidity of the vibrating arm.
As a result, a precise quartz crystal vibrating piece accommodated in the case or the package is not easily damaged, so that a strong quartz crystal device can be obtained.

According to an eighth aspect of the present invention, there is provided a mobile phone device using a crystal device having a crystal resonator element accommodated in a package, wherein the crystal resonator element is entirely formed of crystal, and a base portion. A pair of resonating arms extending in parallel from the base, each resonating arm having a groove extending in the length direction, and the groove of each resonating arm includes a small groove divided in the width direction. This is achieved by a cellular phone device in which a control clock signal is obtained by a quartz crystal device formed so as to be continuously arranged in parallel along the length direction of the vibrating arm.

According to the ninth aspect of the present invention, there is provided an electronic apparatus using a quartz crystal device in which a quartz crystal vibrating piece is accommodated in a package, wherein the quartz crystal vibrating piece is entirely formed of quartz, a base, A pair of resonating arms extending in parallel from the base, each resonating arm having a groove extending in the longitudinal direction, and a small groove divided in the width direction in each groove of each resonating arm. This is achieved by an electronic apparatus in which a clock signal for control is obtained by a quartz crystal device formed so as to be continuous in a state of being arranged in parallel along the length direction of the arm.

1 and 2 show an embodiment of a quartz crystal device of the present invention. FIG. 1 is a schematic plan view thereof, and FIG. 2 is a schematic cross-sectional view taken along the line CC of FIG.
In the figure, the crystal device 30 shows an example in which a crystal resonator is configured. The crystal device 30 accommodates a crystal resonator element 32 in a package 36. Package 36 is
For example, a plurality of substrates formed by molding an aluminum oxide ceramic green sheet as an insulating material are stacked and then sintered. Each of the plurality of substrates is formed with a predetermined hole on the inner side thereof, so that a predetermined internal space S2 is formed on the inner side when stacked.
This internal space S2 is a housing space for housing the crystal vibrating piece.
That is, as shown in FIG. 2, in this embodiment, the package 36 is formed by, for example, stacking the first laminated substrate 52, the second laminated substrate 53, and the third laminated substrate 54 from below. ing.

In the inner space S2 of the package 36, in the vicinity of the left end portion, the second laminated substrate 53 that is exposed to the inner space S2 and constitutes the inner bottom portion has, for example, an electrode formed by nickel plating and gold plating on tungsten metallization. Portions 31, 31 are provided.
The electrode portions 31 are connected to the outside to supply a driving voltage. Conductive adhesives 43, 43 are applied on the electrode portions 31, 31, and the conductive adhesives 43, 4 are applied.
3, the base 51 of the crystal vibrating piece 32 is placed, and the conductive adhesives 43, 43 are cured. In addition, as the conductive adhesives 43 and 43, a synthetic resin agent as an adhesive component exhibiting a bonding force and containing conductive particles such as fine silver particles can be used. A system-based or polyimide-based conductive adhesive or the like can be used.

Further, as shown in FIG. 2, through holes 37a and 37b that are continuous with the two laminated substrates constituting the package 36 are formed near the center of the bottom surface of the package 36, thereby opening the package 36 to the outside. A through-hole 37 is provided. Out of the two through holes constituting the through hole 37, the outer through hole 37b, which is the second hole, has a larger inner diameter than the first hole 37a that opens inside the package. Yes. Thereby, the through-hole 37 is
In FIG. 2, a stepped opening having a downward stepped portion 65 is formed. It is preferable that a metal coating portion is provided on the surface of the step portion 65.

Here, as the metal sealing material 38 filled in the through-hole 37, for example, a sealing material not containing lead is preferably selected. For example, silver brazing, Au / Sn alloy, Au / Ge alloy Selected from etc. Correspondingly, it is preferable to form nickel plating and gold plating on the tungsten metallization in the metal coating portion on the surface of the step portion 65.
A lid body 39 is joined to the open upper end of the package 36 by using a brazing material 33 to be sealed. The lid 39 is preferably sealed and fixed to the package 36, and then, as shown in FIG. In order to adjust the frequency, it is made of a material that transmits light, particularly, thin glass.
As a glass material suitable for the lid 39, for example, borosilicate glass is used, for example, as a thin glass manufactured by the downdraw method.

The quartz crystal vibrating piece 32 is formed by etching a quartz crystal by a manufacturing process to be described later. In the case of the present embodiment, the quartz crystal vibrating piece 32 is formed in a small size in order to obtain a required performance. The shape shown in the schematic plan view of FIG.
That is, the crystal vibrating piece 32 is cut out from a single crystal of crystal so that the X axis shown in FIG. 3 is an electric axis, the Y axis is a mechanical axis, and the Z axis is an optical axis. The quartz crystal vibrating piece 32 includes a base 51 fixed to the package 36 side as described later, and a pair of vibrating arms 34 extending in parallel in a bifurcated manner upward in the drawing with the base 51 as a base end. A so-called tuning fork type crystal vibrating piece having a shape 35 like the tuning fork is used.

As shown in FIG. 3, notches 51 a and 51 b that are concave in the width direction are formed at the ends of the base 51 on the vibrating arms 34 and 35 side. The base end portions of the vibrating arms 34 and 35 slightly protrude outward.
Thereby, leakage of vibration from the vibrating arms 34 and 35 toward the base 51 is prevented.
In order to avoid the complexity shown in the figure and to facilitate understanding, in FIG. 1 to FIG. 3, the excitation electrode and other electrodes formed on the crystal vibrating piece 32 are omitted.

The vibrating arms 34 and 35 of the crystal vibrating piece 32 have grooves 56 and 57 extending in the length direction, respectively.
Is formed. The grooves 56 and 57 are formed on both front and back surfaces of the vibrating arms 34 and 35. Each of the groove portions 56 and 57 is formed as a plurality or a plurality of pairs in the length direction in which the small grooves 61 and the small grooves 62 partitioned by the lattice-like frame portion 75 are arranged in parallel. The small groove 61 and the small groove 62 are enlarged and shown on the right side of FIG. And each groove part 56 and 57 is the same structure, and the small groove 61 and the small groove 62 which comprise these are also the same structure. 4 is a sectional view taken along the line DD of FIG. 3 for one small groove 61, and FIG. 5 is an end view taken along the line EE of FIG. 3 for the small groove 61 and the small groove 62 arranged in parallel.

In FIG. 3, lead electrodes 58 and 59 are formed in the vicinity of both ends in the width direction of the end portion (lower end portion in FIG. 3) of the base portion 51 of the crystal vibrating piece 32. Each extraction electrode 58, 59 is
It is similarly formed on the back surface (not shown) of the base 51 of the crystal vibrating piece 32.
These lead electrodes 58 and 59 are portions connected to the package-side electrode portions 31 and 31 shown in FIG. 1 by the conductive adhesives 43 and 43 as described above. And
The lead electrodes 58 and 59 are connected to excitation electrodes (described later) provided in the groove portions 56 and 57 of the vibrating arms 34 and 35.

As shown in FIGS. 3 to 5, the groove portion 56 has small grooves 61 and 62, and the groove portion 57 also has small grooves 61 and 62. Since these have the same structure, only the groove portion 57 of the vibrating arm 35 that avoids complexity will be described. As shown in FIG. 5, the small grooves 61 and 62 are provided on the vibrating arm 3.
5 are small grooves 61 and 62 divided in the width direction. Further, the small grooves 61 and 62 are formed as shown in FIG.
As shown in FIG. 5, a plurality of pairs or a large number of pairs are continuously formed at a predetermined interval in the length direction of the vibrating arm 35, that is, the Y direction. These small grooves 61 and 62 are substantially rectangular as shown by a width A and a length B, respectively, in plan view.
As shown in FIGS. 4 and 5, the small groove 61 is a bottomed groove, and the frame portion 7 that forms the small groove 61.
The wall portions 61a, 61a, 61b, and 61b of 5 have a slope that gradually increases the groove depth toward substantially the center of the small groove. That is, these wall portions 61a, 61a and 61b,
61b has a lattice-like structure as shown in FIG. 3 in a plan view, and has an inclination as shown in FIG. 4 and FIG. Thereby, since the vicinity of the base end of each wall part becomes a strong structure, the groove parts 56 and 57 become structurally strong, and the retainability of a form is high.

Further, as shown in FIG. 5, electrodes are formed in the small grooves 61 and 62, and the electrodes are formed in the small grooves 61.
, 62 are integrated into the excitation electrode 63.
In addition to the excitation electrode 63, excitation electrodes 64 are formed on both side surfaces of the vibrating arm 35, and the excitation electrode 63 and the excitation electrode 64 have different polarities. The excitation electrode 63 and the excitation electrode 64 are connected to the corresponding extraction electrodes 58 and 59 of FIG.
The excitation electrode 63 and the excitation electrode 64 are formed so as to face each other with the quartz material constituting each wall portion of the small grooves 61 and 62 interposed therebetween, so that the drive voltage applied via the extraction electrodes 58 and 59 can be reduced. By the action, an electric field can be generated in the quartz material sandwiched between the excitation electrode 63 and the excitation electrode 64, and thereby the flexural vibration of the vibrating arm 35 is efficiently generated.
Here, the form of the small groove is not limited to that shown in FIG. For example, the small grooves 61, 61, 61, 61 and the small grooves 62, 62, 62, 62 arranged in the length direction of the vibrating arms 34, 35 have the same length B in the example of FIG. Small grooves having different lengths B may be arranged. For example, in the vicinity of the roots of the vibrating arms 34 and 35, the length B of the small groove can be about 100 μm, and the length B of the small groove provided on the distal end side of the vibrating arms 34 and 35 can be about 90 μm.

Next, FIG. 6 is a process diagram for explaining an example of the manufacturing method of the quartz crystal vibrating piece 32 of the present embodiment, and each process includes the above-described cut surfaces of the vibrating arms 34 and 35 of FIG. One vibrating arm 35
Only the region corresponding to is shown in the order of steps, but the entire crystal vibrating piece 32 including the vibrating arms 34 and 35 proceeds in the same manner.

With reference to these drawings, a preferable method for manufacturing the quartz crystal vibrating piece 32 will be described.
In FIG. 6A, a substrate 71 made of a quartz material having a size capable of separating a plurality or a large number of quartz crystal vibrating pieces 32 is prepared. The substrate 71 is formed by cutting a single crystal of quartz, for example, and processing it into a tuning fork as described below.
First, the substrate 71 is cut from a single crystal of crystal so that the X axis shown in FIG. 3 is an electric axis, the Y axis is a mechanical axis, and the Z axis is an optical axis. Further, when cutting from a single crystal of quartz, in the above-described orthogonal coordinate system composed of the X-axis, Y-axis, and Z-axis, the XY plane composed of the X-axis and the Y-axis is about minus 5 degrees clockwise around the X-axis. Or tilted 5 degrees.

(Corrosion-resistant film formation process)
Next, as shown in FIG. 6B, a corrosion-resistant film 72 is formed on the surface (front and back surfaces) of the substrate 71 by a technique such as sputtering or vapor deposition. As shown in the drawing, a corrosion-resistant film 72 is formed on both the front and back surfaces of the quartz substrate 71. The corrosion-resistant film 72 includes, for example, a chromium layer as a base layer,
It is comprised by the gold coating layer coat | covered on it.
In the following process, the same processing is performed on the upper and lower surfaces in FIG.
In order to avoid complications, only the upper surface will be described.

(Patterning process)
Next, as shown in FIG. 6C, a resist 73 is applied to the entire surface (resist application step). Then, as shown in FIG. 6D, a mask 74 is disposed on the resist 73 for patterning the outer shape. As the resist 73, for example, OFPR-800LB 34c
p can be preferably used.
In the mask 74, the illustrated outer edge corresponds to the outer shape of the vibrating arm, and the inner opening or hole corresponds to the small grooves 61 and 62 arranged in parallel with the groove 57. Of course, when both negative and positive techniques are selected based on the photolithography technique, the relationship between the opening of the mask 74 and its surroundings is reversed.

(Outline formation etching process)
Thus, as shown in FIG. 6D, a mask 74 is arranged on the resist 73 for patterning the outer shape, and after exposure, the exposed resist 73 is removed as shown in FIG. 6E.
Next, as shown in FIG. 6F, the metal coating layer which is a corrosion resistant film is removed in the order of Au and Cr corresponding to the removed resist portion. Then, as shown in FIG. 6G, the exposed substrate 71 is exposed.
For example, the etching of the outer shape of the crystal vibrating piece and the etching of the groove are simultaneously performed using a hydrofluoric acid solution as an etching solution (outer shape forming etching step). This outer shape forming etching process is 100 to 200 minutes, and is the same as the time required for the conventional outer shape forming etching process, and the required time varies depending on the concentration, type, temperature, and the like of the hydrofluoric acid solution. In this embodiment, hydrofluoric acid and ammonium fluoride are used as an etching solution, and the concentration is 1: 1 as a concentration ratio.
The outer shape forming etching process is completed under the condition of a temperature of 65 ° ± 1 ° (Celsius).

In this outer shape formation etching process, as shown in the figure, the outer shape of the vibrating arm is completely etched in the process from FIG. 6 (f) to FIG. 6 (g). On the inside, small grooves 61 and 62 are formed. This is because the small grooves 61 and 6 of the mask 74 are formed.
By setting dimensions A and B in FIG. 3 as described later as the size of 2, this portion is half-etched without penetrating.

In other words, in this embodiment, the projection or fin-like irregular shape or irregular shape portion 65 is formed based on the anisotropy due to etching of the quartz, but the same function is the small groove 61 that is the opening inside the mask 74. , 62 also proceeds at a location corresponding to 62. Due to the anisotropy due to the etching of the quartz crystal, the small grooves 61 and 62 do not penetrate in the outer shape forming etching process, and become a bottomed groove. In this process, the wall surfaces of the small grooves 61 and 62 are substantially in the form described in FIGS.
Then, after performing the outer shape forming etching step, as shown in FIG. 6H, the resist 73 and the corrosion-resistant film 72 are all removed in order to obtain a tuning fork type crystal piece.

(Electrode film formation process)
Subsequently, an electrode of the crystal vibrating piece 32 is formed.
That is, an electrode film is formed of a metal to be an electrode by sputtering or the like on the entire outer surface of the crystal piece on which no electrode is formed. The electrode film covers, for example, Au with Cr as a base layer.
Next, a resist is applied to the outside by, for example, a spray method, patterning is performed, and the resist not exposed to light is removed by exposure.
Then, the electrode film exposed by removing the resist is removed by etching in the order of Au and Cr.
Thereby, as shown in FIG. 6I, a quartz crystal vibrating piece in which the excitation electrode 63 and the excitation electrode 64 are formed is completed. In FIG. 6I, only the cross section of the vibrating arm 35 is shown.

As described above, according to the manufacturing method of the present embodiment, the groove forming process (half etching), which has been conventionally performed separately from the outer shape forming etching, is performed simultaneously with the etching for forming the outer shape of the crystal vibrating piece 32. Is significantly simplified and the time required for the manufacturing process is shortened.
Further, in the conventional manufacturing process shown in FIGS. 15 to 17, the outer shape forming etching and the half etching for forming the groove are separately performed, so that the grooves 9 and 12 are offset from the outer shape of the vibrating arm 6. There is a risk that it will be formed. If the formation positions of the grooves 9 and 12 are shifted in this way, the vibration performance of the crystal vibrating piece 3 may be adversely affected.

On the other hand, in the manufacturing process of this embodiment, the outer shape forming etching and the half etching process for forming the groove are patterned together and performed in one step, so that the position of the small groove is shifted with respect to the vibrating arm. This can be prevented, and the crystal vibrating piece 32 is caused by the groove etching process.
There is no adverse effect on the vibration performance of the.
Further, in the manufacturing method of this embodiment, in each of the groove portions 56 and 57 of the vibrating arms 34 and 35 of the crystal vibrating piece 32, for example, in the groove portion 57, the wall portions 61 a and 61 that form the small groove 61.
A slope is formed such that a, 61b, 61b gradually increase the groove depth toward the approximate center of the small groove. As a result, the vicinity of the base end of each wall portion has a strong structure, so that the rigidity of the vibrating arm 35 is improved. As a result, a strong crystal vibrating piece 32 that is not easily damaged can be obtained.

FIG. 7 shows that the crystal thickness t as the thickness of the vibrating arms 34 and 35 of the crystal vibrating piece 32 is 10.
In the case of 0 μm and 130 μm, the length B of the small groove in FIG. 3 is taken on the vertical axis and the width A of the small groove is taken on the horizontal axis, and the outer shape forming etching process is performed for 140 minutes under the above-mentioned conditions. It is the graph which plotted the numerical value when it becomes a groove | channel of a bottom. When the region from the origin of each graph is a bottomed groove, that is, a range in which half etching is performed without the groove bottom portion penetrating.

As shown in the figure, when the width A of the small groove is 15 μm or less at t = 130 μm,
Regardless of the length B of the small groove, the necessary condition for forming the small groove that does not penetrate can be satisfied. When the width A of the small groove exceeds 15 μm at t = 130 μm, the length B of the small groove is set to 250.
By setting it to μm or less, the necessary condition for forming a small groove that does not penetrate can be satisfied.

8 to 11, the crystal thickness t is set to 100 μm, and the etching time is changed to 140 minutes (FIG. 8), 160 minutes (FIG. 9), 180 minutes (FIG. 10), and 200 minutes (FIG. 11). It is a graph of the case.
As shown in these drawings, a bottomed small groove can be formed by satisfying the above-mentioned conditions almost regardless of the difference in etching time.

FIG. 12 is a diagram showing a schematic configuration of a digital mobile phone device as an example of an electronic apparatus using the crystal device according to the above-described embodiment of the present invention.
In the figure, a microphone 308 for receiving the voice of the sender and a speaker 309 for outputting the received content as a voice output are provided, and further, an integrated circuit or the like as a control unit connected to the modulation and demodulation unit of the transmission / reception signal. A controller (CPU) 301 is provided.
The controller 301 is an information input / output unit 302 including an LCD as an image display unit and an operation key for inputting information in addition to modulation and demodulation of transmission / reception signals, and a memory as information storage means including a RAM, a ROM 303 is controlled. For this reason, the crystal device 30 is attached to the controller 301, and its output frequency is changed to the controller 301.
Is used as a clock signal suitable for the control content by a predetermined frequency dividing circuit (not shown) or the like. Crystal device 3 attached to this controller 301
0 may not be a single crystal device 30 but may be an oscillator that combines the crystal device 30 and a predetermined frequency dividing circuit.

The controller 301 is further connected to a temperature compensated crystal oscillator (TCXO) 305,
The temperature compensated crystal oscillator 305 is connected to the transmission unit 307 and the reception unit 306. As a result, even if the basic clock from the controller 301 fluctuates when the environmental temperature changes,
It is corrected by the temperature compensated crystal oscillator 305 and supplied to the transmission unit 307 and the reception unit 306.

In this way, by using the crystal device 30 according to the above-described embodiment in an electronic apparatus such as the digital cellular phone device 300, the crystal vibrating piece 3 housed in the package is used.
2 is less likely to be damaged by vibration and can be manufactured at a low cost because the manufacturing process is simplified, it is possible to obtain a digital mobile phone device 300 having a reliable quality and a low cost.

The present invention is not limited to the above-described embodiment. Each configuration of each embodiment can be appropriately combined or omitted, and can be combined with other configurations not shown.
In addition, the present invention provides a crystal resonator as long as the crystal resonator element is accommodated in a package.
Regardless of the name of the crystal oscillator, etc., it can be applied to all crystal devices.
Further, three or more small grooves constituting the groove portion of the vibrating arm may be arranged in the width direction.
Further, if at least a plurality of pairs are provided in the length direction, it is not always necessary to provide a large number of pairs.
Furthermore, in the above-described embodiment, a box-shaped material using a crystal material is used for the package. However, the present invention is not limited to such a configuration, and a crystal vibrating piece is accommodated in a cylindrical case of metal or ceramic. The present invention can be applied to any package or case with any case.

1 is a schematic plan view showing a first embodiment of a quartz crystal device of the present invention. The CC sectional schematic sectional drawing of FIG. FIG. 2 is a schematic plan view of a crystal vibrating piece housed in the package of the crystal device of FIG. 1. The DD line cutting | disconnection end view of FIG. FIG. 4 is an end view taken along line E-E in FIG. 3. The schematic sectional drawing which shows in order the manufacturing process of the quartz crystal vibrating piece accommodated in the quartz crystal device of FIG. When the crystal thickness t as the thickness of the vibrating arm is 100 μm and 130 μm, respectively, the small groove length B is plotted on the vertical axis and the small groove width A is plotted on the horizontal axis. A graph plotting the numerical values when the groove does not penetrate and becomes a bottomed groove. FIG. 8 is a graph similar to FIG. 7 when the crystal thickness t is set to 100 μm and the etching time is 140 minutes. FIG. 8 is a graph similar to FIG. 7 when the crystal thickness t is set to 100 μm and the etching time is 160 minutes. FIG. 8 is a graph similar to FIG. 7 when the crystal thickness t is set to 100 μm and the etching time is 180 minutes. The graph similar to FIG. 7 when the crystal thickness t is set to 100 μm and the etching time is 200 minutes. 1 is a diagram showing a schematic configuration of a digital mobile phone device as an example of an electronic apparatus using a crystal device according to an embodiment of the present invention. The schematic perspective view which shows the structural example of the conventional quartz crystal vibrating piece. FIG. 14 is a schematic end view taken along line AA in FIG. 13. FIG. 14 is a schematic cross-sectional view sequentially illustrating manufacturing steps of the crystal vibrating piece in FIG. 13. FIG. 14 is a schematic cross-sectional view sequentially illustrating manufacturing steps of the crystal vibrating piece in FIG. 13. FIG. 14 is a schematic cross-sectional view sequentially illustrating manufacturing steps of the crystal vibrating piece in FIG. 13.

Explanation of symbols

30 ... Quartz device, 32 ... Quartz vibrating piece, 34, 35 ... Vibrating arm, 56, 57 ... Groove, 6
1, 62 ... small groove, 65 ... irregular shape.

Claims (6)

It is formed by a crystal, base and, an the base portion or al-rolled Building pair of vibrating arms, a quartz crystal resonator element having a groove extending in the length direction of the vibration arms,
When the thickness t of each of the vibrating arms is 100 μm or more and less than 130 μm, the width A of the groove is 5 μm or less . It is formed by a crystal, base and, an the base portion or al-rolled Building pair of vibrating arms, a quartz crystal resonator element having a groove extending in the length direction of the vibration arms,
When the thickness t of each vibrating arm is 100 μm or more and less than 130 μm and the width A (μm) of the groove exceeds 5 μm, the length B (μm) of the groove satisfies the following formula: Piece.
B ≦ 358.9120 × A ^−0.4186 (1) A quartz crystal resonator element formed of quartz, comprising a base and a pair of vibrating arms extending from the base, each having a groove extending in the lengthwise direction,
  When the thickness t of each vibrating arm is 130 μm or more, the width A of the groove is 15 μm or less. A quartz crystal resonator element formed of quartz, comprising a base and a pair of vibrating arms extending from the base, each having a groove extending in the lengthwise direction,
  When the thickness t of each vibrating arm is 130 μm or more and the width A (μm) of the groove exceeds 15 μm, the length B (μm) of the groove satisfies the following formula.
B ≦ 986.0359 × A ^-0.5239         (2) A crystal device having a crystal resonator element housed in a case or package,
Crystal devices wherein the crystal vibrating piece, characterized by crystal vibrating piece der Rukoto according to any one of claims 1 to 4. An electronic device using a crystal device that contains a crystal resonator element in a package,
Electronic equipment wherein the crystal vibrating piece, characterized in that the quartz crystal device Ru crystal vibrating piece der according to any one of claims 1 to 4, to obtain a clock signal for control.

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