JP2003273680A - Method of manufacturing piezoelectric vibrator, piezoelectric vibrator, and piezoelectric device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a piezoelectric vibrator in which a piezoelectric device is miniaturized without deteriorating the characteristics of a piezoelectric vibrator. <P>SOLUTION: In the method of manufacturing the piezoelectric vibrator by separating an inverted mesa shaped vibrator formed on a piezoelectric substrate from the piezoelectric substrate, the method successively performs a step (S64) for forming the thin portion of the piezoelectric substrate by etching along the contour of an area to form the piezoelectric vibrator on the piezoelectric substrate simultaneously with the formation of an inverted mesa portion on the inverted mesa shaped piezoelectric vibrator and a step (S69) for separating the piezoelectric vibrator from the piezoelectric substrate by radiating CO2 lasers along the thin portion. Thus, the problem of interference between the portion of the piezoelectric vibrator left from folding away and the side face of a cavity. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a piezoelectric vibrating piece, a piezoelectric vibrating piece, and a piezoelectric device.

[0002]

2. Description of the Related Art In order to obtain a constant frequency in an electric circuit, a piezoelectric vibrator 201 having a piezoelectric vibrating piece 220 mounted on a package 205 or the like is widely used as shown in FIG. The piezoelectric vibrating piece 220 is one in which the excitation electrodes 226 are formed on both surfaces of a flat plate made of a piezoelectric material such as quartz.
The thinner the piezoelectric material plate is, the more the piezoelectric vibrating reed 22.
The resonance frequency of 0 becomes high. Therefore, reverse mesa portions (recesses) 224 are formed on both surfaces of the piezoelectric material flat plate, and the reverse mesa portions 2 are formed.
An inverted mesa type piezoelectric vibrating piece 220 having an excitation electrode 226 formed on the bottom surface of 24 has been developed.

The inverted mesa type piezoelectric vibrating piece is manufactured as follows. 12 to 14 are process diagrams of a method of manufacturing an inverted mesa-type piezoelectric vibrating piece according to the related art. Each of FIGS. 12 to 14 is a cross-sectional view of the piezoelectric substrate in a portion corresponding to line FF in FIG. 11. A plurality of piezoelectric vibrating pieces are simultaneously formed on the piezoelectric substrate 240 cut out from a piezoelectric material such as quartz. First, as shown in FIG. 12 (1), Au / C is used as a corrosion resistant film on the surface of the piezoelectric substrate 240.
The r film 251 is formed (S261). Furthermore, the contour 242 of the piezoelectric vibrating piece is patterned on the resist 252 by performing photolithography (S26).
2). Then, using the resist 252 as a mask, Au /
By etching the Cr film 251, the contour 242 of the piezoelectric vibrating piece is patterned (S263). After that, when the resist 252 is removed, the state shown in FIG.

Next, as shown in FIG. 12C, photolithography is performed to pattern the contour 242 of the piezoelectric vibrating piece and the inverted mesa portion 244 on the resist 253 (S264). Then, as shown in FIG. 13A, the piezoelectric substrate 240 is etched by using the Au / Cr film 251 and the resist 253 as a mask to form an outline 242 of the piezoelectric vibrating piece (S265).
On the other hand, using the resist 253 as a mask, the Au / Cr film 2
By performing the etching of 51, the reverse mesa portion 244 is patterned (S266). And FIG. 13 (2)
As shown in FIG.
The reverse mesa portion 244 is formed by etching the piezoelectric substrate 240 using 3 as a mask (S267).
After that, the resist 253 and the Au / Cr film 251 are removed (S268), so that the blank of the piezoelectric vibrating piece is completed as shown in FIG.

Next, as shown in FIG. 14A, an Au / Cr film 25 is formed as an electrode material film on the surface of the piezoelectric substrate 240.
5 is formed (S269). Further, photolithography is performed to pattern the electrode 246 on the resist 256 (S270). Then, the Au / Cr film 255 is etched using the resist 256 as a mask to form the electrode 246 (S271). Then, if the resist 256 is removed, the piezoelectric vibrating piece 220 is completed on the piezoelectric substrate 240 as shown in FIG. Note that, as shown in FIG. 15, the piezoelectric vibrating piece 220 is connected to the piezoelectric substrate 240 only by the breaking portion 249. Therefore, the force 25 in the vertical direction is applied to the piezoelectric vibrating piece 220.
By adding 9, the piezoelectric vibrating piece 220 is broken and separated from the piezoelectric substrate 240 (S272). Then, as shown in FIG. 11, the piezoelectric vibrating piece 220 is mounted in the package 205.

[0006]

In the method of manufacturing a piezoelectric vibrating piece according to the prior art, since the piezoelectric vibrating piece is broken from the piezoelectric substrate, the piezoelectric vibrating piece has the unfolded portion 229 as shown in FIG. Therefore, when mounting the piezoelectric vibrating piece 220, the unfolded portion 229 and the cavity 20 are
It is necessary to prevent the interference with the side surface of 6.

The package 205 is formed by laminating ceramic sheets and the like, and the cavity 206 is formed by blanking the ceramic sheets.
The four corners of 06 must be arc-shaped. Therefore,
When mounting the piezoelectric vibrating piece 220, the corner portions 220 a of the piezoelectric vibrating piece 220 and the circular arc portions 206 at the four corners of the cavity 206 are mounted.
It is necessary to prevent interference with a.

As described above, if the size of the package 205 is increased in order to prevent the interference between the piezoelectric vibrating piece 220 and the cavity 206, the recent demand for downsizing of the piezoelectric vibrator 201 cannot be met. On the other hand, if the size of the piezoelectric vibrating element is reduced, it is generally CI (crystal impedance).
The value and frequency-temperature characteristic will be deteriorated.

The present invention has been made in view of the above problems, and an object thereof is to provide a method of manufacturing a piezoelectric vibrating piece and a piezoelectric vibrating piece capable of miniaturizing a piezoelectric device without deteriorating the characteristics of the piezoelectric vibrating piece. To do. Another object of the present invention is to provide a piezoelectric device that can be miniaturized. It is another object of the present invention to provide a method of manufacturing a piezoelectric vibrating piece, which can reduce manufacturing cost by simplifying the manufacturing process.

[0010]

The present invention is based on the development of a method of cutting a piezoelectric material such as quartz by utilizing local heating. Natural crystal has a property of absorbing infrared rays having a wavelength of 3.0 μm or more. On the other hand, the CO2 laser can irradiate infrared rays having a wavelength of 9.6 μm or 10.6 μm. Therefore, CO is added to piezoelectric materials such as quartz.
By irradiating two lasers, the piezoelectric material such as quartz can be locally heated efficiently. The temperature of crystal is 4
Since it has an inflection point at 00 to 500 ° C. and its crystal state changes, there has been no idea so far to heat and cut a piezoelectric material such as quartz. However, if the influence of local heating increases, the characteristics of the piezoelectric vibrating piece may deteriorate, so the piezoelectric vibrating piece is separated from the piezoelectric substrate without increasing the thermal effect, and thus the following configuration is adopted.

First, in the method of manufacturing a piezoelectric vibrating piece according to the first aspect of the present invention, the piezoelectric vibrating piece formed on a piezoelectric substrate is separated from the piezoelectric substrate to manufacture the piezoelectric vibrating piece. Along the contour of the formation region of the piezoelectric vibrating piece in the piezoelectric substrate, by forming a thin portion of the piezoelectric substrate, by performing local heating along the thin portion,
The step of separating the piezoelectric vibrating piece from the piezoelectric substrate is sequentially performed.

In this case, since the local heating is performed along the thin portion of the piezoelectric substrate, the piezoelectric vibrating reed can be separated from the piezoelectric substrate without increasing the thermal effect. Then, the unfolded portion does not occur on the piezoelectric vibrating piece. As a result, the interference between the unfolded portion and the side surface of the cavity does not pose a problem, and the package can be made smaller than before. Therefore, the piezoelectric device can be downsized. At that time, since the piezoelectric vibrating piece does not need to be downsized, the CI value and the frequency temperature characteristic are not deteriorated.

The method of manufacturing a piezoelectric vibrating piece according to a second aspect of the invention is a method of manufacturing the piezoelectric vibrating piece by separating the piezoelectric vibrating piece formed on a piezoelectric substrate from the piezoelectric substrate. From the corners of the piezoelectric vibrating reed forming area of the piezoelectric substrate to all or a part of the contour of the piezoelectric vibrating reed forming area, along the contour of the piezoelectric vibrating reed forming area. The step of separating the piezoelectric vibrating piece from the piezoelectric substrate by performing local heating is sequentially performed.

In this case, since the crack starts from the notch as a starting point, the piezoelectric vibrating reed can be separated from the piezoelectric substrate without increasing the thermal effect. Further, since the unfolded portion does not occur on the piezoelectric vibrating piece, the piezoelectric device can be downsized without deteriorating the characteristics of the piezoelectric vibrating piece.

Further, in the method of manufacturing a piezoelectric vibrating piece according to the invention of claim 3, the piezoelectric vibrating piece is a reverse mesa type piezoelectric vibrating piece. The method for manufacturing a piezoelectric vibrating piece according to the present invention can be applied to manufacturing an AT-cut piezoelectric vibrating piece or a surface acoustic wave element piece. Among the AT-cut piezoelectric vibrating pieces, the reverse mesa-type piezoelectric vibrating piece is particularly suitable for local heating. Since the influence of is blocked by the outer frame and does not extend to the vibrating portion, the piezoelectric vibrating piece can be separated from the piezoelectric substrate without adversely affecting the characteristics of the piezoelectric vibrating piece.

Further, in the method of manufacturing a piezoelectric vibrating piece according to the present invention, the step of forming the thin portion is performed by etching at the same time as forming the reverse mesa portion of the piezoelectric vibrating piece. Thereby, the manufacturing process can be simplified.

Further, in the method of manufacturing the piezoelectric vibrating piece according to the invention of claim 5, the local heating step is performed while vacuum adsorbing the formation area of the piezoelectric vibrating piece from the opposite side of the piezoelectric substrate. . As a result, tensile stress is generated on the surface of the piezoelectric substrate that is locally heated, so that the piezoelectric vibrating reed can be separated from the piezoelectric substrate without increasing the thermal effect.

Further, in the method of manufacturing a piezoelectric vibrating piece according to the invention of claim 6, the local heating step is performed by irradiating a CO 2 laser. As described above, the piezoelectric material such as quartz absorbs infrared rays emitted from the CO 2 laser, and therefore local heating can be efficiently performed to separate the piezoelectric vibrating piece from the piezoelectric substrate. The local heating step can be performed using an electron beam, a halogen lamp, an ultrasonic wave generator, or the like, in addition to the CO2 laser.

Further, in the method of manufacturing a piezoelectric vibrating piece according to the invention of claim 7, there is provided a step of forming a hole penetrating the piezoelectric substrate at a corner portion of a region where the piezoelectric vibrating piece is formed. As a result, since arcuate portions are formed at the four corners of the piezoelectric vibrating piece, interference with the arcuate portions at the four corners of the cavity does not pose a problem, and the package can be made smaller than before. Therefore, the piezoelectric device can be downsized. At that time, since the piezoelectric vibrating piece does not need to be downsized, the CI value and the frequency temperature characteristic are not deteriorated.

Further, in the method of manufacturing a piezoelectric vibrating piece according to the invention of claim 8, a conductive film is formed on the inner surface of the through hole to ensure electrical continuity between the electrodes formed on both surfaces of the piezoelectric vibrating piece. It is configured to include steps. This allows
Since it is not necessary to apply the conductive adhesive twice to ensure electrical continuity between the electrodes, the manufacturing process can be simplified.

Further, in the method of manufacturing a piezoelectric vibrating piece according to the invention of claim 9, the method for manufacturing the piezoelectric vibrating piece by separating the inverted mesa type piezoelectric vibrating piece formed on the piezoelectric substrate from the piezoelectric substrate. Then, a step of providing a hole penetrating the piezoelectric substrate at a corner of the formation region of the piezoelectric vibrating piece,
A step of forming a cut from the through hole in all or a part of the contour of the formation region of the piezoelectric vibrating piece, and forming electrodes on both surfaces of the piezoelectric vibrating piece, and at the same time, forming a conductive film on the inner surface of the through hole. And a step of forming the piezoelectric vibrating piece on one surface side of the piezoelectric substrate while vacuum adsorbing the piezoelectric vibrating piece forming area on the other surface side of the piezoelectric substrate along the contour of the piezoelectric vibrating piece forming area. Is applied to separate the piezoelectric vibrating reed from the piezoelectric substrate. As a result, the piezoelectric device can be downsized without deteriorating the characteristics of the piezoelectric vibrating piece. Further, since the conductive film is formed on the inner surface of the through hole at the same time when the electrodes are formed, the manufacturing process can be simplified.

On the other hand, the piezoelectric vibrating reed according to the tenth aspect of the invention is manufactured by using the method for manufacturing a piezoelectric vibrating reed according to any one of the first to ninth aspects. As a result, the piezoelectric device can be downsized without deteriorating the characteristics of the piezoelectric vibrating piece.

Further, the piezoelectric vibrating piece according to the invention of claim 11 has a structure in which the tips of the four corners of the rectangular piezoelectric vibrating piece are removed. As a result, interference with the circular arcs at the four corners of the cavity does not pose a problem, and the package can be made smaller than before. Therefore, the piezoelectric device can be downsized without deteriorating the characteristics of the piezoelectric vibrating piece.

Further, in the piezoelectric vibrating piece according to the invention of claim 12, the tips of the four corners of the rectangular piezoelectric vibrating piece are removed, and a conductive film is formed on the side surface of the piezoelectric vibrating piece at the removed tips, The electrodes formed on both sides of the piezoelectric vibrating piece are configured to ensure electrical continuity between the electrodes. This eliminates the need to apply the conductive adhesive twice to ensure electrical continuity between the electrodes, thus simplifying the manufacturing process.

On the other hand, a piezoelectric device according to a thirteenth aspect of the present invention is configured to be manufactured by using the piezoelectric vibrating piece according to any one of the tenth to twelfth aspects. This makes it possible to provide a piezoelectric device that can be miniaturized.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a method for manufacturing a piezoelectric vibrating piece, a piezoelectric vibrating piece and a piezoelectric device according to the present invention will be described in detail with reference to the accompanying drawings. It should be noted that what is described below is only one aspect of the embodiment of the present invention, and the present invention is not limited thereto.

First, the first embodiment will be described.
FIG. 1 shows a flowchart of a method of manufacturing a piezoelectric vibrating piece according to the first embodiment. The method for manufacturing the piezoelectric vibrating piece according to the first embodiment is a method for manufacturing the piezoelectric vibrating piece by separating an inverted mesa-type piezoelectric vibrating piece formed on a piezoelectric substrate from the piezoelectric substrate. Simultaneously with the formation of the reverse mesa portion of the piezoelectric vibrating piece, a step of forming a thin portion of the piezoelectric substrate by etching along the contour of the piezoelectric vibrating piece forming region of the piezoelectric substrate (S64), and CO2 along the thin portion. The step of separating the piezoelectric vibrating piece from the piezoelectric substrate by irradiating the laser (S69) is sequentially performed.

As shown in FIG. 4, the inverted mesa type piezoelectric vibrating piece 2 is used.
Reference numeral 0 denotes a flat plate made of a piezoelectric material such as quartz, with opposite mesa portions (recesses) 24 formed on both sides. The thickness of the piezoelectric material in the reverse mesa portion 24 is, for example, about 10 μm, and the thickness of the piezoelectric material in the outer frame 25 thereof is, for example, about 100 μm. Then, an excitation electrode 26 for exciting the piezoelectric material is formed at the center of the bottom surface of the inverted mesa portion 24. Excitation electrode 2
6 is formed of a conductive material such as an Au / Cr film. On the other hand, a part of the outer frame 25 is enlarged and used as a mount portion for the package 5. Connection electrodes 27 are formed on both sides and side surfaces of the mount portion to ensure continuity with the excitation electrodes 26. As a result, it is possible to energize the excitation electrode 26 from the outside.

2 and 3 show process diagrams of the method for manufacturing the piezoelectric vibrating piece according to the first embodiment. Each of FIGS. 2 and 3 is a cross-sectional view of the piezoelectric substrate in a portion corresponding to the line CC of FIG. In the first embodiment, a plurality of inverted mesa type piezoelectric vibrating pieces are simultaneously formed on a piezoelectric substrate cut out from a piezoelectric material such as quartz.

First, as shown in FIG. 2A, an Au / Cr film 51 is formed as a corrosion resistant film on the surface of the piezoelectric substrate 40 (S61). The Au / Cr film 51 is formed by a sputtering method or the like. Furthermore, we perform photolithography,
The contour 42 of the piezoelectric vibrating piece forming region of the piezoelectric substrate 40 and the inverted mesa portion 44 are patterned on the resist 52 (S62). Then, the Au / Cr film 51 is etched using the resist 52 as a mask to pattern the contour 42 and the inverted mesa portion 44 of the piezoelectric vibrating piece (S63). Then, if the resist 52 is removed, the state shown in FIG.

Then, the piezoelectric substrate 40 is etched by using the Au / Cr film 51 as a mask, so that as shown in FIG.
As shown in (3), the contour 42 of the piezoelectric vibrating piece, the reverse mesa portion 44, and the thin portion 42a of the piezoelectric substrate are formed (S6).
4). The thickness of the thin portion 42a is, for example, the piezoelectric substrate 4
It is about 10% of the thickness of 0. The piezoelectric substrate such as crystal is etched by wet etching with time management. A liquid obtained by mixing hydrofluoric acid and ammonium fluoride in a weight ratio of 1: 1 is used as the etching liquid. After that, A
If the u / Cr film 51 is removed (S65), the state shown in FIG.

Next, as shown in FIG. 3A, an Au / Cr film 55 is formed as an electrode material film on the surface of the piezoelectric substrate 40 (S66). Further, photolithography is performed to pattern the electrode 46 on the resist 56 (S67). Then, using the resist 56 as a mask,
The electrode 46 is formed by etching the Au / Cr film 55 (S68). Then, when the resist 56 is removed, the state shown in FIG.

Next, a CO2 laser is irradiated along the thin portion 42a formed on the contour of the piezoelectric vibrating piece (S6).
9). As described above, the piezoelectric material such as crystal can be locally heated by irradiating the piezoelectric material such as crystal with a CO 2 laser. However, crystal temperature is 400-50
Since it has an inflection point at 0 ° C. and its crystalline state changes, the characteristics of the piezoelectric vibrating piece may be deteriorated when its thermal influence expands. However, in the first embodiment, the thin portion 42
Since a is locally heated, cracks occur early. And
Before the influence of heat is increased, the piezoelectric vibrating reed 20 is separated from the piezoelectric substrate 40 as shown in FIG. With the above, the piezoelectric vibrating piece 20 is completed.

FIG. 4 is an explanatory view of a piezoelectric vibrator on which the piezoelectric vibrating piece according to the first embodiment is mounted. The same figure (1) is B-
It is a plane sectional view in the B line, and the figure (2) is a side sectional view in the AA line. The piezoelectric vibrating reed 20 manufactured as described above can be used as the piezoelectric vibrator 1 by mounting it on the package 5. Package 5
Is formed by laminating ceramic sheets and the like. Further, on the bottom surface of the cavity 6, electrodes 9 and wiring patterns (not shown)
Are formed to enable conduction with external terminals (not shown) formed on the back surface of the package 5.

Then, the piezoelectric vibrating piece 20 is mounted inside the cavity 6 in a cantilevered state. Specifically, first, the piezoelectric vibrating piece 20 is inserted into the cavity 6. Since the piezoelectric vibrating piece 20 manufactured as described above has no unfolded portion, it does not interfere with the side surface of the cavity 6. Then, the connection electrode 27 of the piezoelectric vibrating piece 20 is arranged on the electrode 9 coated with the conductive adhesive 2. Since the connection electrode 27 is electrically connected to the excitation electrode 26, the excitation electrode 26 of the piezoelectric vibrating piece 20 can be energized from the external terminal on the back surface of the package 5 as described above. A lid member 10 is attached to the upper portion of the package 5 to maintain the inside of the package 5 in a nitrogen atmosphere or the like.

The piezoelectric vibrating reed according to the first embodiment is
By forming an oscillation circuit in combination with an integrated circuit element, it can be used as a piezoelectric oscillator. For example, the piezoelectric vibrator 1 shown in FIG. 4 and an integrated circuit element (not shown)
The piezoelectric oscillator module can be formed by mounting and on a module substrate on which a wiring pattern is formed. Moreover, a piezoelectric oscillator package can be formed by mounting the integrated circuit element together with the piezoelectric vibrating piece 20 inside the package 5 shown in FIG.

By the method of manufacturing the piezoelectric vibrating piece according to the first embodiment, the piezoelectric device can be downsized without deteriorating the characteristics of the piezoelectric vibrating piece. In this regard, in the method for manufacturing a piezoelectric vibrating piece according to the conventional technique, since a breakage remaining portion is generated in the piezoelectric vibrating piece, when the piezoelectric vibration piece is mounted on the package, interference between this breakage remaining portion and the side surface of the cavity is prevented. Had to prevent. And if the package is made larger, it is not possible to meet the recent demand for miniaturization of the piezoelectric vibrator. On the other hand, if the piezoelectric vibrating piece is made smaller,
Generally, there is a problem that the CI value and the frequency temperature characteristic are deteriorated.

However, in the method of manufacturing the piezoelectric vibrating piece according to the first embodiment, the step of forming the thin portion of the piezoelectric substrate along the contour of the region where the piezoelectric vibrating piece is formed in the piezoelectric substrate, and the CO 2 along the thin portion. And a step of separating the piezoelectric vibrating piece from the piezoelectric substrate by irradiating a laser. In this case, since the thin portion of the piezoelectric substrate is irradiated with the CO2 laser, the piezoelectric vibrating piece can be separated from the piezoelectric substrate without increasing the thermal effect. Then, the unfolded portion does not occur on the piezoelectric vibrating piece. As a result, the interference between the unfolded portion and the side surface of the cavity does not pose a problem, and the package can be made smaller than before. Therefore, the piezoelectric device can be downsized. At that time, since the piezoelectric vibrating piece does not need to be downsized, the CI value and the frequency temperature characteristic are not deteriorated.

Further, in the method of manufacturing the piezoelectric vibrating piece according to the first embodiment, the reverse mesa portion is formed by etching, and at the same time, the thin portion is formed on the contour of the piezoelectric vibrating piece, so that the manufacturing process is simplified. Can be converted. Specifically, in the method of manufacturing a piezoelectric vibrating piece according to the related art, twelve steps 261 to 272 are required, whereas in the method of manufacturing a piezoelectric vibrating piece according to the first embodiment,
The piezoelectric vibrating reed can be manufactured by the nine steps 61 to 69. Thereby, the manufacturing cost can be reduced.

Next, the second embodiment will be described. FIG. 5A shows a plan view of the piezoelectric vibrating piece according to the second embodiment. Further, FIG. 5B is an explanatory diagram of a piezoelectric vibrator on which the piezoelectric vibrating piece according to the second embodiment is mounted. Note that FIG.
(2) is a plan sectional view of a portion corresponding to the line BB in FIG. 4. Piezoelectric vibrating piece 120 according to the second embodiment
Removes the tip portions of the four corners of the rectangular piezoelectric vibrating piece 120, forms the conductive film 128 on the side surfaces of the piezoelectric vibrating piece at the removed tip portions, and connects the connecting electrodes 127 to each other formed on both surfaces of the piezoelectric vibrating piece 120. It ensures continuity.

That is, arcuate portions 121 which are convex toward the inside of the piezoelectric vibrating piece at the four corners of the rectangular piezoelectric vibrating piece 120.
To form. Note that instead of the arc portion 121, a chamfer may be formed, or an arc portion that is convex toward the outside of the piezoelectric vibrating piece may be formed. Further, the rigidity of the piezoelectric vibrating piece is ensured by forming the corner portion of the reverse mesa portion 124 close to the circular arc portion 121 to be reduced inward and ensuring the width of the outer frame 125. Then, the piezoelectric vibrating piece 1 in the arc portion 121
A conductive film 128 is formed on the side surface of 20. In particular,
The same Au / Cr film as the electrode material film is formed as the conductive film. The conductive film 128 is formed so as to be conductive with the connection electrodes 127 formed on both surfaces of the piezoelectric vibrating piece. As a result, the connection electrodes 127 formed on both surfaces of the piezoelectric vibrating piece can be electrically connected to each other.

Next, a method of manufacturing the above-described piezoelectric vibrating piece will be described. FIG. 6 shows a flowchart of the method for manufacturing the piezoelectric vibrating piece according to the second embodiment. 7 to 9 are process diagrams of the method for manufacturing the piezoelectric vibrating piece according to the second embodiment. 7 and 9 are sectional views of the piezoelectric substrate in a portion corresponding to line GG in FIG. 5, and FIG. 8 is a plan view of the piezoelectric substrate.

In the method of manufacturing the piezoelectric vibrating piece according to the second embodiment, the piezoelectric vibrating piece is formed on the corners of the piezoelectric vibrating piece forming region on the piezoelectric substrate.
When a hole is formed through the piezoelectric substrate (S166), a step is formed from the through hole in a part of the contour of the piezoelectric vibrating piece forming region (S167), and electrodes are formed on both surfaces of the piezoelectric vibrating piece. At the same time, the step of forming an electrode material coating film on the inner surface of the through hole (S168), and the piezoelectric vibrating piece forming area is vacuum-adsorbed on the one surface side of the piezoelectric substrate while the piezoelectric vibrating piece forming area is formed on the other surface side of the piezoelectric substrate. The step of separating the piezoelectric vibrating piece from the piezoelectric substrate by irradiating the piezoelectric substrate with the CO 2 laser (S171). Note that the description of the same configuration as that of the first embodiment will be omitted.

First, as shown in FIG. 7A, an Au / Cr film 151 is formed as a corrosion resistant film on the surface of the piezoelectric substrate 140 (S161). Further, photolithography is performed to pattern the reverse mesa portion 144 on the resist 152 (S162). Then, the Au / Cr film 151 is etched by using the resist 152 as a mask to pattern the reverse mesa portion 144 (S16).
3). After that, if the resist 152 is removed, FIG.
The state becomes as shown in (2). Then, the Au / Cr film 151
Using the mask as a mask, the piezoelectric substrate 140 is etched to form the inverted mesa portion 144 (S164). After that, if the Au / Cr film 151 is removed (S165),
The state shown in FIG. 7C is obtained.

Next, as shown in FIG. 8, the piezoelectric substrate 140
The hole 141 which penetrates is formed (S166). Note that FIG. 8 is a plan view of the piezoelectric substrate. On the piezoelectric substrate 140, a plurality of piezoelectric vibrating piece forming regions 120a are arranged without a gap. That is, the corner of the formation area of one piezoelectric vibrating piece is adjacent to the corner of the formation area of the other three piezoelectric vibrating pieces. Therefore, a through hole 141 centered on the corner is formed. Thereby, the arc portions 121 can be simultaneously formed at the corners of the four piezoelectric vibrating pieces. The through hole 141 is formed by CO2 laser irradiation, etching, sandblasting, or the like.

Next, a notch 142 is formed from the through hole 141 in a part of the outline 120b of the piezoelectric vibrating piece forming region (S167). To form the notch 142, a notch forming jig in which a cutting tool is arranged in the same shape as the tip of a Phillips screwdriver is used. The notch forming jig has its center axis aligned with the center axis of the through hole 141, and its cutting tool has a contour 120b of the piezoelectric vibrating piece forming region.
Place it along. Then, the notch forming jig is pressed against the piezoelectric substrate 140 from the vertical direction. Then, the bite of the notch forming jig bites into the piezoelectric substrate, and the outline 12 of the piezoelectric vibrating piece forming region is formed from the through hole 141.
A notch 142 is formed in a part of 0b. In this case, it is possible to simultaneously form the cuts in the contour 120b of the formation region of the four piezoelectric vibrating pieces adjacent to the through hole 141. In addition, you may form a notch in the whole contour 120b of the formation area of a piezoelectric vibrating piece.

Next, as shown in FIG. 9A, on the surface of the piezoelectric substrate 140, an Au / Cr film 15 is formed as an electrode material film.
5 is formed (S168). At the same time, an Au / Cr film is also formed on the inner surface of the through hole. Further, photolithography is performed to pattern the electrode 146 with respect to the resist 156 (S169). At that time, the resist is left on the inner surface of the through hole. Then, the Au / Cr film 155 is etched using the resist 156 as a mask to form an electrode 146 (S170). Then, when the resist 156 is removed, the state shown in FIG. 9B is obtained.

Next, the piezoelectric vibrating piece 120 is separated from the piezoelectric substrate 140 by irradiating a CO2 laser along the contour 120b of the piezoelectric vibrating piece forming region shown in FIG. 8 (S171). Here, while vacuum-sucking the formation area 120a of the piezoelectric vibrating piece on the one surface side of the piezoelectric substrate 140,
The other side of the piezoelectric substrate is irradiated with a CO2 laser.
When the piezoelectric vibrating piece forming area 120a is vacuum-adsorbed on the one surface side of the piezoelectric substrate 140, the contour 120b of the piezoelectric vibrating piece forming area on the other surface side of the piezoelectric substrate 140 is
Tensile stress occurs. In addition, from the through hole 141 to the contour 1
The notch formed in a part of 20b serves as a starting point of crack generation. Then, by irradiating the contour 120b with a CO2 laser, a crack propagates along the contour 120b, and finally, the piezoelectric vibrating piece 120 from the piezoelectric substrate 140.
Are separated. Since the piezoelectric vibrating piece forming region 120a is vacuum-adsorbed on the one surface side of the piezoelectric substrate 140, the separated piezoelectric vibrating piece 120 does not drop. As described above, the piezoelectric vibrating piece 120 is completed as shown in FIG.

As described above, in the method for manufacturing a piezoelectric vibrating piece according to the second embodiment, a cut is made from a corner of the piezoelectric vibrating piece forming area on the piezoelectric substrate to a part of the contour of the piezoelectric vibrating piece forming area. The configuration includes a step of forming the piezoelectric vibrating piece and a step of separating the piezoelectric vibrating piece from the piezoelectric substrate by irradiating a CO2 laser along the contour of the formation region of the piezoelectric vibrating piece. In this case, since the notch serves as the starting point and the crack propagates, the piezoelectric vibrating piece can be separated from the piezoelectric substrate without increasing the thermal effect. Further, since the unfolded portion does not occur on the piezoelectric vibrating piece, the same effect as that of the first embodiment can be obtained.

Further, in the method of manufacturing the piezoelectric vibrating piece according to the prior art, it is necessary to prevent interference between the corners of the piezoelectric vibrating piece and the circular arcs of the four corners of the cavity. However, in the method for manufacturing a piezoelectric vibrating piece according to the second embodiment, through holes are provided at the corners of the piezoelectric vibrating piece forming region of the piezoelectric substrate, and the tip portions of the four corners of the rectangular piezoelectric vibrating piece are removed. did.
As a result, as shown in FIG.
The interference with the circular arc portions 106a at the four corners of 6 does not pose a problem, and the package 105 can be made smaller than the conventional one. Therefore, the piezoelectric vibrator 101 can be downsized. At this time, since the piezoelectric vibrating piece 120 does not need to be downsized, the CI value and the frequency temperature characteristic are not deteriorated.

Further, in the method of manufacturing the piezoelectric vibrating piece according to the second embodiment, since the electrodes are formed on both surfaces of the piezoelectric vibrating piece, the step of forming the electrode material coating film on the inner surface of the through hole is adopted. It is possible to ensure electrical continuity between the electrodes formed on both surfaces of the piezoelectric vibrating piece without adding a new manufacturing process.

As shown in FIG. 5B, when the piezoelectric vibrating piece 120 is mounted on the package 105, the conductive adhesive 102 is applied on the electrode 109, and the piezoelectric vibrating piece is applied thereon. 120 connection electrodes 127 are arranged. Here, in the piezoelectric vibrating reed according to the second embodiment, the piezoelectric vibrating reed 1
Since the mutual conduction of the connection electrodes 127 formed on both surfaces of the connection electrode 20 is secured, it is not necessary to apply the conductive adhesive again to the upper surface of the connection electrode to secure the mutual conduction of the connection electrodes. Therefore, the manufacturing process can be simplified.

Further, in the piezoelectric vibrating reed according to the second embodiment, at the corners of the piezoelectric vibrating reed 120, conduction between the connection electrodes 127 formed on both surfaces is ensured, so only the portion where the corner is located. The conductive adhesive 102 may be applied to the. This saves conductive adhesive. Further, since the conductive adhesive is applied to the positions separated from each other, it is possible to prevent the conductive adhesive from short-circuiting.

On the other hand, in the conventional method of manufacturing a piezoelectric vibrating piece, the piezoelectric vibrating piece is separated from the piezoelectric substrate by etching. As shown in FIG. 10, the piezoelectric substrate 140 is
Due to the anisotropy of the piezoelectric material such as quartz, it is etched into a wedge shape with the cut angle θ as the depression angle. Then, the piezoelectric substrate 140 can be blanked only when the wedge-shaped etching grooves 148a and 148b on the front and back surfaces overlap each other. Therefore, in order to blank the piezoelectric substrate 140 having the thickness t, the width of the etching groove needs to be t / tan θ. Therefore, the number of piezoelectric vibrating pieces to be taken from one piezoelectric substrate is naturally limited.

However, in the method of manufacturing the piezoelectric vibrating piece according to the second embodiment, since the piezoelectric vibrating piece is separated from the piezoelectric substrate by the CO 2 laser, there is almost no separation space between the adjacent piezoelectric vibrating piece forming regions. No need to provide. Therefore, it is possible to arrange the formation regions of the plurality of piezoelectric vibrating reeds on the piezoelectric substrate without a gap, and it is possible to maximize the number of piezoelectric vibrating reeds to be taken from one piezoelectric substrate.

[0056]

According to the method of manufacturing the piezoelectric vibrating piece of the present invention, the piezoelectric vibrating piece formed on the piezoelectric substrate is separated from the piezoelectric substrate to manufacture the piezoelectric vibrating piece. A step of forming a thin portion of the piezoelectric substrate along the contour of the formation region of the piezoelectric vibrating piece, and a step of separating the piezoelectric vibrating piece from the piezoelectric substrate by performing local heating along the thin portion. And so on.

A method of manufacturing the piezoelectric vibrating piece by separating the piezoelectric vibrating piece formed on the piezoelectric substrate from the piezoelectric substrate, comprising: The step of forming a notch in all or a part of the contour of the formation area of the piezoelectric vibrating piece, and by performing local heating along the contour of the formation area of the piezoelectric vibrating piece, the piezoelectric vibrating piece from the piezoelectric substrate. And a step of separating the above are sequentially performed. With these, the piezoelectric device can be downsized without deteriorating the characteristics of the piezoelectric vibrating piece.

[Brief description of drawings]

FIG. 1 is a flowchart of a method of manufacturing a piezoelectric vibrating piece according to a first embodiment.

FIG. 2 is a first step diagram of the method of manufacturing the piezoelectric vibrating piece according to the first embodiment.

FIG. 3 is a second process diagram of the method of manufacturing the piezoelectric vibrating piece according to the first embodiment.

FIG. 4 is an explanatory view of a piezoelectric vibrator on which the piezoelectric vibrating piece according to the first embodiment is mounted, (1) is a plan sectional view taken along line BB, and (2) is a side surface taken along line AA. FIG.

5A is a plan view of the piezoelectric vibrating piece according to the second embodiment, and FIG. 5B is an explanatory view of a piezoelectric vibrator on which the piezoelectric vibrating piece according to the second embodiment is mounted. 4 is a plan sectional view of a portion corresponding to line BB in FIG.

FIG. 6 is a flowchart of a method of manufacturing a piezoelectric vibrating piece according to a second embodiment.

FIG. 7 is a first process diagram of the method of manufacturing the piezoelectric vibrating piece according to the second embodiment.

FIG. 8 is a second process diagram of the method of manufacturing the piezoelectric vibrating piece according to the second embodiment.

FIG. 9 is a third step diagram of the method of manufacturing the piezoelectric vibrating piece according to the second embodiment.

FIG. 10 is an explanatory diagram of the relationship between the thickness of the piezoelectric substrate and the width of the etching groove.

11A and 11B are explanatory views of a piezoelectric vibrator in which a piezoelectric vibrating piece according to a conventional technique is mounted, (1) is a plan sectional view taken along line EE, and (2) is a side sectional view taken along line DD. Is.

FIG. 12 is a first process diagram of a method of manufacturing a piezoelectric vibrating piece according to a conventional technique.

FIG. 13 is a second process diagram of the method of manufacturing a piezoelectric vibrating piece according to the conventional technique.

FIG. 14 is a third process diagram of the method of manufacturing the piezoelectric vibrating piece according to the related art.

FIG. 15 is an explanatory diagram of a method for separating a piezoelectric vibrating piece from a piezoelectric substrate according to a conventional technique.

[Explanation of symbols]

1 ... Piezoelectric vibrator, 2 ... Conductive adhesive, 5 ...
Package, 6 ... Cavity, 9 ... Electrode, 10
……… Lid member, 20 ………… Piezoelectric vibrating piece, 24 ……… Inverse mesa part, 25 ……… Outer frame, 26 ……… Excitation electrode, 27 ……
... Connection electrode, 40 ... Piezoelectric substrate, 42 ... Outline of piezoelectric vibrating piece, 44 ... Inverse mesa portion, 46 ... Electrode, 51
……… Au / Cr film, 52, 53 ……… Resist, 55
……… Au / Cr film, 56 ……… Resist, 101 ……
… Piezoelectric vibrator, 102 ………… Conductive adhesive, 105 ……
… Package, 106 ……… Cavity, 109 ………
Electrode, 120 ... Piezoelectric vibrating piece, 120a ... Forming area, 120b ... Outline, 121 ... Arc portion, 124
………… Reverse mesa part, 125 ………… Outer frame, 126 ………… Excitation electrode, 127 ………… Connection electrode, 128 ………… Conductive film, 1
40 ......... Piezoelectric substrate, 141 ...
... notches 144 ... reverse mesa portion, 146 ... electrodes, 148a, 148b ... etching grooves, 151
…… Au / Cr film, 152 ………… Resist, 155 ……
... Au / Cr film, 156 ......... resist, 201 ...
Piezoelectric vibrator, 205 ... Package, 206 ... Cavity, 206a ... Arc part, 220 ... Piezoelectric vibrating piece, 220a ... Corner part, 224 ... Inverse mesa part, 2
26 ... Excitation electrodes, 227 ... Connection electrodes, 229 ...
...... Unfolded part, 240 ………… Piezoelectric substrate, 242 ……
… Contours, 244 ………… Inverse mesas, 246 ………… Electrodes, 2
49 ………… Tear-off part, 251 ………… Au / Cr film, 2
52,253 ......... Resist, 255 ......... Au / Cr
Membrane, 256 ………… Resist, 259 ………… Vertical force.

Claims (13)

[Claims] 1. A method of manufacturing the piezoelectric vibrating piece by separating a piezoelectric vibrating piece formed on a piezoelectric substrate from the piezoelectric substrate, the method comprising: , A step of forming a thin portion of the piezoelectric substrate, and a step of separating the piezoelectric vibrating reed from the piezoelectric substrate by locally heating along the thin portion, the piezoelectric vibration. Piece manufacturing method. 2. A method of manufacturing the piezoelectric vibrating piece by separating a piezoelectric vibrating piece formed on a piezoelectric substrate from the piezoelectric substrate, wherein the piezoelectric vibrating piece is formed on a corner of a region where the piezoelectric vibrating piece is formed. The step of forming a notch in all or a part of the contour of the formation region of the piezoelectric vibrating piece, and by performing local heating along the contour of the formation region of the piezoelectric vibrating piece, the piezoelectric vibrating piece from the piezoelectric substrate. A method of manufacturing a piezoelectric vibrating piece, comprising the steps of: 3. The method of manufacturing a piezoelectric vibrating piece according to claim 1, wherein the piezoelectric vibrating piece is an inverted mesa-type piezoelectric vibrating piece. 4. The method of manufacturing a piezoelectric vibrating piece according to claim 3, wherein the step of forming the thin portion is performed by etching at the same time as forming the reverse mesa portion of the piezoelectric vibrating piece. 5. The piezoelectric element according to claim 1, wherein the local heating step is performed from the opposite side of the piezoelectric substrate while vacuum adsorbing the formation region of the piezoelectric vibrating piece. A method for manufacturing a vibrator element. 6. The method of manufacturing a piezoelectric vibrating piece according to claim 1, wherein the local heating step is performed by irradiating a CO 2 laser. 7. The piezoelectric vibrating piece according to claim 1, further comprising the step of providing a hole penetrating the piezoelectric substrate at a corner of a region where the piezoelectric vibrating piece is formed. Production method. 8. The method according to claim 7, further comprising a step of forming a conductive film on the inner surface of the through hole to ensure electrical continuity between electrodes formed on both surfaces of the piezoelectric vibrating piece. A method for manufacturing a piezoelectric vibrating piece. 9. A method of manufacturing the piezoelectric vibrating piece by separating an inverted mesa type piezoelectric vibrating piece formed on a piezoelectric substrate from the piezoelectric substrate, the method comprising the steps of: Forming a hole penetrating the piezoelectric substrate; forming a cut from the through hole in all or part of the contour of the formation region of the piezoelectric vibrating piece; and forming electrodes on both sides of the piezoelectric vibrating piece. At the same time, the step of forming a conductive film on the inner surface of the through-hole, the one side of the piezoelectric substrate, while vacuum adsorbing the formation region of the piezoelectric vibrating piece, the other side of the piezoelectric substrate, the piezoelectric CO2 along the contour of the vibrating bar formation area
A step of separating the piezoelectric vibrating piece from the piezoelectric substrate by irradiating a laser, and a method of manufacturing the piezoelectric vibrating piece. 10. A piezoelectric vibrating piece manufactured by using the method for manufacturing a piezoelectric vibrating piece according to claim 1. Description: 11. A piezoelectric vibrating piece, which is obtained by removing tip portions of four corners of a rectangular piezoelectric vibrating piece. 12. A rectangular piezoelectric vibrating reed is removed at four corners, and a conductive film is formed on the side surface of the piezoelectric vibrating reed at the removed front end so that the electrodes formed on both sides of the piezoelectric vibrating reciprocal are mutually connected. 12. The piezoelectric vibrating piece according to claim 11, wherein continuity is secured. 13. A piezoelectric device manufactured by using the piezoelectric vibrating piece according to claim 10. Description: