Piezoelectric vibration piece aggregate wafer and piezoelectric vibration piece

Abstract

To provide a piezoelectric vibration piece aggregate wafer capable of suppressing drop of a piezoelectric vibration piece from a support part in the middle of manufacture of the piezoelectric vibration piece, and a piezoelectric vibration piece which is broken off from the piezoelectric vibration piece aggregate wafer.SOLUTION: A piezoelectric vibration piece aggregate wafer 1 comprises a plurality of crystal vibration piece part 2, a support part 3 supporting the crystal vibration piece part 2, and a connection part 4 connecting each crystal vibration piece part 2 with the support part 3. In the piezoelectric vibration piece aggregate wafer 1, the connection part 4 includes a first principal surface 41, which is orthogonal with a thickness direction of the connection part 4, and a second principal surface 42 which is a rear-side surface in a view from the first principal surface 41. The first principal surface 41 includes a recess portion 5, which is recessed in the thickness direction, and the second principal surface 42 includes a step portion 6 rising from a position opposed with the recess portion 5 in a projection direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a piezoelectric vibrating piece aggregate wafer in which a plurality of piezoelectric vibrating pieces are held by a support, and a piezoelectric vibrating piece obtained from the piezoelectric vibrating piece aggregate wafer. [Background technology]

[0002] In the manufacture of piezoelectric resonators for use in piezoelectric devices, a method is known in which a quartz wafer is etched to obtain a large number of piezoelectric resonators. For efficiency, the large number of piezoelectric resonators are supported on a support via connecting parts, and each piezoelectric resonator is broken off at the connecting parts to separate them.

[0003] As such a piezoelectric vibrating piece aggregate wafer, one has been disclosed in which groove-like slits are formed at the connecting parts to make it easier to break off the piezoelectric vibrating pieces made of quartz from the support part at the connecting parts (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Actual Publication No. 03-039922 Summary of the Invention [Problem to be solved by the invention]

[0005] However, as the thickness of the piezoelectric vibration piece to be obtained becomes thinner, when the technology of creating a slit in the connecting portion as described in Patent Document 1 is applied, the strength of the slit decreases, and the connecting portion may break during manufacturing, causing the piezoelectric vibration piece to fall off from the support portion.

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a piezoelectric vibrating piece aggregate wafer that can prevent the piezoelectric vibrating piece from falling off from a support portion during the manufacturing process of the piezoelectric vibrating piece, and a piezoelectric vibrating piece obtained from the piezoelectric vibrating piece aggregate wafer. [Means for solving the problem]

[0007] The present invention is a piezoelectric vibrating piece assembly wafer having a plurality of piezoelectric vibrating piece portions, a support portion supporting the piezoelectric vibrating piece portions, and a connecting portion connecting each of the piezoelectric vibrating piece portions to the support portion, wherein the connecting portion has a first main surface perpendicular to a thickness direction of the connecting portion and a second main surface which is a back surface as viewed from the first main surface, the first main surface having a recess that is concave in the thickness direction, and the second main surface having a step portion that rises in a convex direction from a position opposite the recess, characterized in that the piezoelectric vibrating piece assembly wafer.

[0008] In the piezoelectric vibrating piece aggregate wafer of the present invention, the first main surface of the connecting portion has a recess that is recessed in the thickness direction of the connecting portion, and the second main surface has a step portion that rises in a convex direction from a position facing the recess. With this configuration, the strength of the connecting portion provided with the recess (slit) is improved, and it is possible to prevent the piezoelectric vibrating piece from falling off the support portion due to the connecting portion breaking during manufacturing.

[0009] Furthermore, when a force is applied in the thickness direction of the piezoelectric vibrating piece to break it off from the support, the end point on the first main surface side where the connecting portion breaks becomes a recess, and the end point on the second main surface side becomes a point where the step portion rises. Therefore, the shape of the fracture surface of the broken piezoelectric vibrating piece can be controlled. In other words, it is possible to prevent damage to the piezoelectric vibrating piece caused by the fracture surface falling on the piezoelectric vibrating piece.

[0010] In addition, the piezoelectric vibrating piece aggregate wafer of the present invention may be configured such that the height of the step portion from the second main surface is equal to or greater than the thickness from the bottom of the recess to the second main surface. With this configuration, the strength of the connecting portion provided with the recess can be sufficiently ensured.

[0011] In addition, the piezoelectric vibrating piece aggregate wafer of the present invention may have a configuration in which the recess has a substantially triangular shape with the bottom as one vertex in a cross-sectional view. With such a configuration, the end point of the first main surface side where the connecting portion breaks can be the bottom of the recess, and the shape of the fracture surface of the piezoelectric vibrating piece can be more reliably controlled.

[0012] The present invention is also characterized in that it is a piezoelectric vibrating piece obtained from the piezoelectric vibrating piece aggregate wafer according to any one of claims 1 to 3. With this configuration, it is possible to obtain a piezoelectric vibrating piece having a desired fracture cross section shape. Effect of the Invention

[0013] According to the present invention, it is possible to provide a piezoelectric vibrating piece aggregate wafer that can prevent the piezoelectric vibrating piece from falling off a support portion during the manufacturing process of the piezoelectric vibrating piece, and a piezoelectric vibrating piece broken off from the piezoelectric vibrating piece aggregate wafer. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a plan view of a piezoelectric vibrating piece aggregate wafer. [Diagram 2] FIG. 2 is a plan view of a first main surface side of one unit of piezoelectric vibrating piece. [Diagram 3] FIG. 4 is a plan view of a second main surface side of one unit of piezoelectric vibrating piece. [Figure 4] FIG. 4 is a side view of a connecting portion according to the first embodiment, as viewed from the width direction (Z′ direction). [Diagram 5] FIG. 3 is an explanatory diagram illustrating the shape of a fracture surface of a broken piezoelectric vibrating piece according to the first embodiment. [Figure 6] FIG. 11 is a side view of a connecting portion according to a second embodiment, as viewed from the width direction (Z′ direction). [Figure 7] FIG. 13 is a side view of a connecting portion according to a third embodiment, as viewed from the width direction (Z′ direction). [Figure 8] FIG. 13 is a side view of a connecting portion according to a fourth embodiment, as viewed from the width direction (Z′ direction). [Figure 9] 13 is an explanatory diagram illustrating the shape of a fracture surface of a broken piezoelectric vibrating piece according to a fourth embodiment. FIG. [Figure 10] FIG. 13 is a side view of a connecting portion according to a fifth embodiment, as viewed from the width direction (Z′ direction). [Figure 11] 13 is an explanatory diagram illustrating the shape of a fracture surface of a broken piezoelectric vibrating piece according to a fifth embodiment. FIG. [Figure 12] FIG. 23 is a side view of a connecting portion according to a sixth embodiment, as viewed from the width direction (Z′ direction). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The Z', X', and Y' directions shown in the drawings are axial directions based on the crystal orientation of the AT-cut quartz crystal piece. The AT-cut quartz crystal piece and the Z', X', and Y' directions will be described in detail in a later paragraph.

[0016] <First embodiment> FIG. 1 is a plan view of a piezoelectric vibrating piece aggregate wafer 1. FIG. The piezoelectric vibrating piece aggregate wafer 1 according to the first embodiment is a quartz crystal vibrating piece aggregate wafer formed entirely in a thin plate shape from quartz crystal. In the piezoelectric vibrating piece aggregate wafer 1, for example, a metal pattern is formed on a quartz crystal plate using resist, and the quartz crystal is etched using the metal pattern, thereby forming the outer shapes of the quartz crystal vibrating piece portion 2 (piezoelectric vibrating piece portion) and the connecting portion 4.

[0017] The support member 3 in this embodiment has a uniform thickness, a rectangular outer frame portion 31 formed so as to surround the periphery (four sides), and a plurality of inner frame portions 32 formed in a lattice shape within the area surrounded by the outer frame portion 31. The outer frame portion 31 and the inner frame portion 32 are integrally formed. The plurality of inner frame portions 32 in this embodiment are lattice-shaped extending in the Z' direction and the X direction, and a plurality of vertical inner frame portions 32a extending in the X direction are arranged at equal intervals and in parallel to each other, and similarly, a plurality of horizontal inner frame portions 32b extending in the Z' direction are arranged at equal intervals and in parallel to each other. In addition, the vertical inner frame portions 32a and the horizontal inner frame portions 32b are formed so as to be perpendicular to each other, and a plurality of support member inner regions 33 surrounded by the vertical inner frame portions 32a and the horizontal inner frame portions 32b are formed. The horizontal inner frame portions 32b are integrally connected to the connecting portion 4 so as to extend inward of each of the plurality of support member inner regions 33. Moreover, the support member inner region 33 is a through region penetrating the piezoelectric vibrating piece aggregate wafer 1 in the thickness direction (Y' direction), and one quartz vibrating piece 2 is disposed in one support member inner region 33. Therefore, in the piezoelectric vibrating piece aggregate wafer 1, a plurality of unit regions A are formed in a matrix pattern, each unit region A being composed of one support member inner region 33 surrounded by a vertical inner frame portion 32a and a horizontal inner frame portion 32b, one quartz vibrating piece portion 2 disposed in the support member inner region 33, and a connecting portion 4 connecting the horizontal inner frame portion 32b and the quartz vibrating piece portion 2. The thickness of the support member 3 can be, for example, 200 μm or less.

[0018] Figure 2 is a plan view of the first main surface 21 side of the quartz vibrating piece 2 of unit area A, Figure 3 is a plan view of the second main surface 22 side of one unit of the quartz vibrating piece 2, and Figure 4 is a side view of the connecting portion 4 in the first embodiment as viewed from the width direction (Z' direction). The quartz vibrating piece 2 in this embodiment is an AT-cut quartz vibrating piece. The quartz vibrating piece 2 has a first main surface 21 perpendicular to the thickness direction (Y' direction) of the quartz vibrating piece 2, a second main surface 22 corresponding to the back side of the first main surface 21, and a side surface connecting the first main surface 21 and the second main surface 22. The quartz vibrating piece 2 has a rectangular shape having long sides and short sides when viewed from the first main surface 21 side, and is connected to the horizontal inner frame part 32b via the connecting part 4 at each end near one of the short sides. In addition, the quartz vibrating piece 2 has excitation electrodes and extraction electrodes (not shown) formed by sputtering or the like. The AT cut is a processing technique in which the artificial quartz crystal is cut at an angle of 35°15′ around the X-axis with respect to the Z-axis, which are the three crystal axes of the artificial quartz crystal, that is, the electric axis (X-axis), the mechanical axis (Y-axis), and the optical axis (Z-axis). In the AT-cut quartz crystal plate, the X-axis coincides with the crystal axis of the quartz crystal. The Y'-axis and Z'-axis correspond to axes inclined 35°15' from the Y-axis and Z-axis of the crystallographic axis of the quartz crystal, respectively. The Y'-axis and Z'-axis directions correspond to the cutting direction when cutting out the AT-cut quartz crystal plate. The quartz crystal vibrating piece 2 may have a thickness of, for example, 30 μm or less.

[0019] In this embodiment, the quartz crystal vibrating piece 2 has the first main surface 21 and the second main surface 22 in a flat plate shape, but is not limited to this configuration. For example, the quartz crystal vibrating piece 2 may have a mesa structure in which at least one of the first main surface 21 and the second main surface 22 has a convex central portion. Alternatively, for example, the quartz crystal vibrating piece 2 may have an inverted mesa structure in which at least one of the first main surface 21 and the second main surface 22 has a concave central portion.

[0020] In this embodiment, the quartz crystal vibrating piece 2 is connected to the horizontal inner frame 32b via the connecting parts 4 near both ends of one of the short sides, but is not limited to this configuration. For example, the connection position with the connecting parts 4 may be near the center of one of the short sides or one of the long sides. The quartz crystal vibrating piece 2 may be connected to the horizontal inner frame 32b via one or three or more connecting parts 4. Furthermore, the quartz crystal vibrating piece 2 may be connected to the outer frame 31 or the vertical inner frame 32a.

[0021] The connecting portion 4 is formed integrally with the support portion 3 and the quartz vibrating piece portion 2, and connects the support portion 3 and the quartz vibrating piece portion 2. The connecting portion 4 is a rectangular thin plate with the X direction as the longitudinal direction, and has a first main surface 41 perpendicular to the thickness direction (Y' direction) of the connecting portion 4, a second main surface 42 corresponding to the back side of the first main surface 41, and a side surface connecting the first main surface 41 and the second main surface 42. The connecting portion 4 of this embodiment is formed so that the length in the width direction (Z' direction) is shorter than the short side of the quartz vibrating piece portion 2. Moreover, the connecting portion 4 of this embodiment is formed so that the thickness (the distance between the first main surface 41 and the second main surface 42) is thinner than the thickness of the support portion 3 and is approximately the same as the thickness of the quartz vibrating piece portion 2, and the second main surface 42 is formed horizontally and continuously with the second main surface 22 of the quartz vibrating piece portion 2.

[0022] The connecting portion 4 has a recess 5 that is recessed in the thickness direction at the end of the first main surface 41 on the crystal vibrating piece portion 2 side in the longitudinal direction. The recess 5 is formed so as to traverse the connecting portion 4 in the width direction, and is composed of a pair of inner wall surfaces 51a, 51b formed on the crystal vibrating piece 2 side and the horizontal inner frame portion 32b side in the longitudinal direction, and a bottom portion 52 connecting the pair of inner wall surfaces 51a, 51b. In this embodiment, of the pair of inner wall surfaces 51a, 51b, the surface formed on the crystal vibrating piece 2 side is the inner wall surface 51a, and the surface formed on the horizontal inner frame portion 32b side is the inner wall surface 52b. In this case, the bottom portion 52 is the most concave position in the recess 5.

[0023] In this embodiment, the recess 5 is formed across the connecting portion 4 in the width direction, but a small area where the recess 5 is not formed may be provided at the end of the quartz crystal vibrating piece 2 on the Z'-axis direction end side. With this configuration, it is possible to suppress chipping of the corners of the quartz crystal vibrating piece 2 caused by etching at the boundary between the quartz crystal vibrating piece 2 and the connecting portion 4.

[0024] The pair of inner wall surfaces 51a, 51b in this embodiment are formed as inclined surfaces inclined with respect to the first main surface 21 of the quartz crystal vibrating piece 2 (the first main surface 41 of the connecting portion 4) so ​​as to approach each other toward the bottom 52, and are connected to each other at the bottom 52. That is, the recess 5 in this embodiment has a substantially triangular (inverted triangle) shape with the bottom 52 as one vertex in a cross-sectional view.

[0025] The recess 5 is formed, for example, by etching using photolithography technology. In particular, when the recess 5 is formed by wet etching, the inner wall surfaces 51a and 51b are naturally formed as a slope that approaches the bottom 52 as in this embodiment, but the slope of the inner wall surface 51 formed by wet etching is often not linear but an arc-like slope, depending on the crystal orientation of the quartz. This is because the slope is formed due to the anisotropy of the quartz. Therefore, the slope of the inner wall surface 51 in this embodiment may be a linear slope as shown in FIG. 4, or may be an arc-like slope.

[0026] In the present embodiment, the recess 5 has a configuration in which the inner wall surfaces 51a, 51b are directly connected to the bottom 52, but the bottom 52 may be the bottom surface, and the inner wall surfaces 51a, 51b may be connected to each other via the bottom 52. In such a configuration, the recess 5 has a substantially quadrangular shape with the connection points between the bottom 52 and the inner wall surfaces 51a, 51b as two vertices. Furthermore, when the heights of the inner wall surfaces 51a and 51b are the same, the shape of the recess 5 is a substantially trapezoidal shape.

[0027] The connecting portion 4 has a step portion 6 that rises in a convex direction in the thickness direction near the end portion of the second main surface 42 on the crystal vibrating piece portion 2 side in the longitudinal direction. The step portion 6 is formed across the entire width in the width direction (Z' direction) of the connecting portion 4, and has a rising point 61 on the second main surface 42. The step portion 6 has a height L4. In this embodiment, the step portion 6 is formed rising at a substantially right angle from the second main surface 42, and is connected to the support portion 3 while maintaining the height L4. It is preferable that the height L4 of the step portion 6 is formed to be equal to or greater than the thickness L5 of the connecting portion 4 at the bottom portion 52 (the thickness from the bottom portion 52 to the second main surface 42). It is more preferable that the height L4 of the step portion 6 is formed to be equal to or greater than the thickness L2 of the connecting portion 4 (the thickness of the quartz crystal vibrating piece portion 2).

[0028] The rising point 61 is disposed at any position within the range of the region facing the recessed portion 5 on the second main surface 42. That is, the step portion 6 is formed so as to rise from a position facing the recessed portion 5. In this embodiment, the rising point 61 is disposed at a position facing the bottom portion 52. In other words, the step portion 6 is provided at a position on the second main surface 42 that overlaps with the recessed portion 5 in a plan view. That is, the connecting portion 4 includes the step portion 6 (thick portion) at a position on the second main surface 42 that overlaps with the recessed portion 5.

[0029] In the connecting portion 4 of the present embodiment, the recess 5 is provided on the first main surface 41, and the step portion 6 is provided on the second main surface 42, but the recess 5 may be provided on the second main surface 42, and the step portion 6 may be provided on the first main surface 41. In other words, the main surface on the side where the recess 5 is provided may be defined as the first main surface 41, and the main surface on the side where the step portion 6 is provided may be defined as the second main surface 42.

[0030] FIG. 5 is an explanatory diagram illustrating the shape of a fracture surface 23 of the broken crystal vibrating piece 20 according to the first embodiment. In such a piezoelectric vibrating piece aggregate wafer 1, by applying a force in the thickness direction to the quartz vibrating piece portion 2, the connecting portion 4 is broken and the quartz vibrating piece portion 2 can be broken off from the support portion 3. The broken off quartz vibrating piece portion 2 can be used as various piezoelectric devices as a quartz vibrating piece 20 (piezoelectric vibrating piece). The quartz vibrating piece 20 in this embodiment has the same thickness in the vibrating portion as the quartz vibrating piece portion 2 before being broken off, and can be used as a piezoelectric device having a frequency in the high frequency band in particular. Such a high frequency band piezoelectric vibrating piece can be suitably used, for example, as a differential oscillator.

[0031] Furthermore, when breaking the connecting portion 4, the breaking end point (breaking point) on the first main surface 41 side is the bottom portion 52. This is because, when a force is applied to the quartz crystal vibrating piece 2 in the thickness direction, stress is most concentrated at the bottom portion 52 on the first main surface 41 side. On the other hand, the breaking end point (breaking point) on the second main surface 42 side is the rising point 61. This is because, when a force is applied to the quartz crystal vibrating piece 2 in the thickness direction, stress is most concentrated at the rising point 61 on the second main surface 42 side.

[0032] Therefore, the crystal vibrating piece 20 has a broken end 24 corresponding to the end of the connecting portion 4 on the crystal vibrating piece portion 2 side before being broken off, as an end portion near the break off. The broken end 24 also has a fracture surface 23 when the crystal vibrating piece portion 2 is broken off at the connecting portion 4 as a part of its outer shape. The fracture surface 23 is formed in a shape connecting the bottom portion 52 and the rising point 61 before being broken off. Therefore, in this embodiment, the broken end 24 has an outer shape including the inner wall surface 51a inclined with respect to the first main surface 21, the fracture surface 23 that is approximately parallel to the side surface of the crystal vibrating piece 20, and the second main surface 42 that is continuous with the second main surface 22 as surfaces. Note that the fracture surface 23 is a surface that is broken by stress, and therefore is a rough surface (rough surface) compared to the first main surface 21, the second main surface 22, and the inner wall surface 51a formed by the etching process.

[0033] With this configuration, it is possible to control the fracture region of the broken portion of the quartz crystal vibrating piece 20 by identifying the positions of the bottom 52 of the recess 5 and the rising point 61 of the step portion 6. In other words, since the fracture region is unlikely to extend into the vibrating portion (vibrating region) of the quartz crystal vibrating piece 20, it is possible to maintain the desired external shape as a vibrator, and to obtain a stable quartz crystal vibrating piece without variation.

[0034] <Second embodiment> FIG. 6 is a side view of a connecting portion 204 according to the second embodiment as viewed from the width direction (Z' direction). In the second embodiment, the configurations of the quartz crystal vibrating piece (piezoelectric vibrating piece) and the support body are similar to those in the first embodiment, and therefore description thereof will be omitted. In the second embodiment, the connecting portion 204 has a recess 205 that is recessed in the thickness direction at an end portion of the first main surface 241 on the side of the quartz-crystal vibrating piece 202 in the longitudinal direction. The recess 205 is formed so as to penetrate the connecting portion 204 in the width direction, and is composed of a pair of inner wall surfaces 251a, 251b and a bottom portion 252 that connects the pair of inner wall surfaces 251a, 251b to each other.

[0035] In the present embodiment, the pair of inner wall surfaces 251a, 251b is formed such that one inner wall surface 251a is formed at a right angle from the first main surface 221 of the quartz crystal vibrating piece portion 202 to the first main surface 221, and the other inner wall surface 251b is formed at a right angle from the first main surface 241 of the connecting portion 204 to the first main surface 241. In other words, the inner wall surfaces 251a, 251b are formed parallel to the thickness direction (Y' direction) of the connecting portion 204. The inner wall surfaces 251a, 251b are connected to each other by the bottom portion 252. Therefore, the bottom portion 252 in the present embodiment is formed as a surface.

[0036] In this embodiment, the height (length) of the inner wall surface 251a is formed to be lower (shorter) than the height (length) of the inner wall surface 251b. In other words, the height (length) of the inner wall surface 251b on the support portion (not shown) side is formed to be higher (longer) than the height (length) of the inner wall surface 251a on the quartz crystal vibrating piece portion 202 side. In further other words, the first main surface 221 of the quartz crystal vibrating piece portion 202 is formed at a lower position in the thickness direction than the first main surface 241 of the connecting portion 204. With this configuration, the strength of the connecting portion 204 can be increased compared to the first embodiment.

[0037] Similarly to the first embodiment, the step portion 206 in this embodiment is formed across the entire width of the connecting portion 204 in the width direction (Z' direction), and has a rising point 261 on the second main surface 242. The step portion 206 is formed rising at a substantially right angle from the rising point 261, and is connected to a support portion (not shown) while maintaining a predetermined height.

[0038] In this embodiment, the rising point 261 is disposed at a position facing the bottom 252 on the second main surface 242. In this embodiment, since the bottom 252 is a surface, the position of the rising point 262 can be any position within the range of the region R1 facing the bottom 252. In this embodiment, the region R1 facing the bottom 252 is equal to the region facing the recess 205.

[0039] <Third embodiment> FIG. 7 is a side view of a connecting portion 304 according to the third embodiment as viewed from the width direction (Z' direction). In the third embodiment, the configurations of the quartz crystal vibrating piece (piezoelectric vibrating piece) and the support body are similar to those in the first embodiment, and therefore a description thereof will be omitted. In the third embodiment, the connecting portion 304 has a recess 305 that is recessed in the thickness direction at an end portion of the first main surface 341 on the side of the quartz-crystal vibrating piece 302 in the longitudinal direction. The recess 305 is formed to penetrate the connecting portion 304 in the width direction, and is composed of a pair of inner wall surfaces 351a, 351b and a bottom portion 352 that connects the pair of inner wall surfaces 351a, 351b to each other.

[0040] In the present embodiment, the pair of inner wall surfaces 351a, 351b are formed such that the inner wall surface 351a on the side of the quartz vibrating piece 302 is formed as an inclined surface inclined with respect to the first main surface 321 of the quartz vibrating piece 302, and the inner wall surface 351b on the side of the support body (not shown) is formed perpendicular to the first main surface 341 of the connecting portion 304. The bottom portion 352 in this embodiment is formed as a surface. Note that, unlike this embodiment, the inner wall surface 351a may be formed perpendicular to the first main surface 321 of the quartz vibrating piece 302, and the inner wall surface 351b may be formed as an inclined surface inclined with respect to the first main surface 341.

[0041] Similarly to the first embodiment, the step portion 306 in this embodiment is formed across the entire width of the connecting portion 304 in the width direction (Z' direction), and has a rising point 361 on the second main surface 342. The step portion 306 is formed to rise at a substantially right angle from the rising point 361, and is connected to a support portion (not shown) while maintaining a predetermined height.

[0042] In this embodiment, the rising point 361 is disposed at an arbitrary position within the range of the region R2 facing the recess 305 on the second main surface 342.

[0043] <Fourth embodiment> FIG. 8 is a side view of a connecting portion 404 according to the fourth embodiment as viewed from the width direction (Z' direction). In the fourth embodiment, the configurations of the quartz crystal vibrating piece (piezoelectric vibrating piece) and the support body are similar to those in the first embodiment, and therefore a description thereof will be omitted. In the fourth embodiment, the connecting portion 404 has a recess 405 that is recessed in the thickness direction at an end of the first main surface 441 on the quartz-crystal vibrating piece 402 side in the longitudinal direction. The recess 405 is formed to penetrate the connecting portion 404 in the width direction, and is composed of a pair of inner wall surfaces 451a, 451b and a bottom portion 452 that connects the pair of inner wall surfaces 451a, 451b. In this embodiment, of the pair of inner wall surfaces 451a, 451b, the surface formed on the quartz-crystal vibrating piece 402 side is referred to as the inner wall surface 451a, and the surface formed on the support portion (not shown) side (the surface facing the inner wall surface 451a) is referred to as the inner wall surface 452b.

[0044] In this embodiment, the pair of inner wall surfaces 451a, 451b are formed as inclined surfaces inclined with respect to the first main surface 421 (first main surface 441 of the connecting portion 404) of the quartz crystal vibrating piece 402 so as to approach each other toward the bottom 452, and are connected to each other at the bottom 452. That is, the recess 405 in this embodiment has a substantially triangular (inverted triangle) shape with the bottom 452 as one vertex in a cross-sectional view.

[0045] Similarly to the first embodiment, the step portion 406 in this embodiment is formed across the entire width of the connecting portion 404 in the width direction (Z' direction), and has a rising point 461 on the second main surface 442. The step portion 406 is formed to rise at a substantially right angle from the rising point 461, and is connected to a support portion (not shown) while maintaining a predetermined height.

[0046] The rising point 461 in this embodiment is provided on the second main surface 442 within a range of a region facing the recess 405, and in a region R3 on the support portion (not shown) side from a position facing the bottom portion 452. In other words, the rising point 461 in this embodiment is provided on the second main surface 442 within a range of a region facing the inner wall surface 451b.

[0047] FIG. 9 is an explanatory diagram illustrating the shape of a fracture surface 423 of a broken crystal vibrating piece 420 according to the fourth embodiment. In the fourth embodiment, as in the first embodiment, by applying a force in the thickness direction to the quartz crystal vibrating piece 402, the connecting portion 404 is broken, and the quartz crystal vibrating piece 402 can be broken off from the support portion (not shown). The broken off quartz crystal vibrating piece 402 can be used as a quartz crystal vibrating piece 420 in various piezoelectric devices.

[0048] Furthermore, when breaking the connecting portion 404, the breaking end point (breaking point) on the first main surface 441 side is the bottom portion 452. This is because, when a force is applied to the quartz crystal vibrating piece 402 in the thickness direction, the most stress is concentrated at the bottom portion 452 on the first main surface 441 side. On the other hand, the breaking end point (breaking point) on the second main surface 442 side is the rising point 461. This is because, when a force is applied to the quartz crystal vibrating piece 402 in the thickness direction, the most stress is concentrated at the rising point 461 on the second main surface 442 side.

[0049] Therefore, the crystal vibrating piece 420 has a broken end 424 that corresponds to the end of the connecting portion 404 on the crystal vibrating piece portion 402 side before being broken off, as an end portion near the break-off. The broken end 424 also has a fracture surface 423 when the crystal vibrating piece portion 402 is broken off at the connecting portion 404 as a part of its outer shape. The fracture surface 423 is formed in a shape that connects the bottom portion 452 and the rising point 461 before being broken off. Therefore, in this embodiment, the broken end 424 has an outer shape that includes an inner wall surface 451a that forms an obtuse angle with the first main surface 421, the fracture surface 423 that forms an acute angle with the second main surface 442, and the second main surface 442 that is continuous with the second main surface 422 as a surface. Since fracture surface 423 is a surface that has been fractured by stress, it is a rough surface compared to first main surface 421, second main surface 422, and inner wall surface 451a that have been formed by etching.

[0050] <Fifth embodiment> FIG. 10 is a side view of a connecting portion 504 according to the fifth embodiment, as viewed from the width direction (Z' direction). In the fifth embodiment, the configurations of the quartz crystal vibrating piece (piezoelectric vibrating piece) and the support body are similar to those in the first embodiment, and therefore a description thereof will be omitted. In the fifth embodiment, the connecting portion 504 has a recess 505 that is recessed in the thickness direction at an end of the first main surface 541 on the quartz-crystal vibrating piece 502 side in the longitudinal direction. The recess 505 is formed to penetrate the connecting portion 504 in the width direction, and is composed of a pair of inner wall surfaces 551a, 551b and a bottom portion 552 that connects the pair of inner wall surfaces 551a, 551b. In this embodiment, of the pair of inner wall surfaces 551a, 551b, the surface formed on the quartz-crystal vibrating piece 502 side is referred to as the inner wall surface 551a, and the surface formed on the support portion (not shown) side (the surface facing the inner wall surface 551a) is referred to as the inner wall surface 551b.

[0051] The pair of inner wall surfaces 551a, 551b in this embodiment are formed as inclined surfaces inclined with respect to the first main surface 521 (first main surface 541 of the connecting portion 504) of the quartz crystal vibrating piece 502 so as to approach each other toward the bottom 552, and are connected to each other at the bottom 552. That is, the recess 505 in this embodiment has a substantially triangular (inverted triangle) shape in a cross-sectional view with the bottom 552 as one vertex.

[0052] Similarly to the first embodiment, the step portion 506 in this embodiment is formed across the entire width of the connecting portion 504 in the width direction (Z' direction), and has a rising point 561 on the second main surface 542. The step portion 506 is formed to rise at a substantially right angle from the rising point 561, and is connected to a support portion (not shown) while maintaining a predetermined height.

[0053] In this embodiment, the rising point 561 is provided within a region of the second main surface 542 facing the recess 505, and in a region R4 on the quartz-crystal vibrating piece 502 side from the position facing the bottom 552. In other words, the rising point 561 is provided within a region of the second main surface 542 facing the inner wall surface 551a. If the rising point 561 is provided at a position facing an end of the inner wall surface 551a on the side opposite the bottom 552, the second main surface 522 of the quartz-crystal vibrating piece 502 will have the same role as the second main surface 542 of the connecting portion 504.

[0054] FIG. 11 is a diagram illustrating the shape of a fracture surface 523 of a broken crystal vibrating piece 520 according to the fifth embodiment. In the fifth embodiment, as in the first embodiment, by applying a force in the thickness direction to the quartz crystal vibrating piece 502, the connecting portion 504 is broken, and the quartz crystal vibrating piece 502 can be broken off from the support portion (not shown). The broken off quartz crystal vibrating piece 502 can be used as a quartz crystal vibrating piece 520 in various piezoelectric devices.

[0055] Furthermore, when breaking the connecting portion 504, the breaking end point (breaking point) on the first main surface 541 side is the bottom portion 552. This is because, when a force is applied to the quartz crystal vibrating piece 502 in the thickness direction, the stress is most concentrated at the bottom portion 552 on the first main surface 541 side. On the other hand, the breaking end point (breaking point) on the second main surface 542 side is the rising point 561. This is because, when a force is applied to the quartz crystal vibrating piece 502 in the thickness direction, the stress is most concentrated at the rising point 561 on the second main surface 542 side.

[0056] Therefore, the crystal vibrating piece 520 has a broken end 524 that corresponds to the end of the connecting portion 504 on the crystal vibrating piece portion 502 side before being broken off, as an end portion near the break-off. The broken end 524 also has a fracture surface 523 when the crystal vibrating piece portion 502 is broken off at the connecting portion 504 as part of its outer shape. The fracture surface 523 is formed in a shape that connects the bottom portion 552 and the rising point 561 before being broken off. Therefore, in this embodiment, the broken end 524 has an outer shape that includes an inner wall surface 551a that forms an obtuse angle with the first main surface 521, the fracture surface 523 that forms an obtuse angle with the second main surface 542, and the second main surface 542 that is continuous with the second main surface 522 as a surface. Since fracture surface 523 is a surface broken by stress, it is a rough surface compared with first main surface 521, second main surface 522, and inner wall surface 551a formed by etching.

[0057] Sixth embodiment FIG. 12 is a side view of a connecting portion 604 according to the sixth embodiment, as viewed from the width direction (Z' direction). In the sixth embodiment, the configurations of the quartz crystal vibrating piece (piezoelectric vibrating piece) and the support member are similar to those in the first embodiment, and therefore a description thereof will be omitted. In the sixth embodiment, the connecting portion 604 has a recess 605 that is recessed in the thickness direction at an end of the first main surface 641 on the quartz-crystal vibrating piece 602 side in the longitudinal direction. The recess 605 is formed to penetrate the connecting portion 604 in the width direction, and is composed of a pair of inner wall surfaces 651a, 651b and a bottom portion 652 that connects the pair of inner wall surfaces 651a, 651b. In this embodiment, of the pair of inner wall surfaces 651a, 651b, the surface formed on the quartz-crystal vibrating piece 602 side is referred to as the inner wall surface 651a, and the surface formed on the support portion (not shown) side (the surface facing the inner wall surface 651a) is referred to as the inner wall surface 652b.

[0058] The pair of inner wall surfaces 651a, 651b in this embodiment are formed as inclined surfaces inclined with respect to the first main surface 621 (first main surface 641 of the connecting portion 604) of the quartz crystal vibrating piece 602 so as to approach each other toward the bottom 652, and are connected to each other at the bottom 652. That is, the recess 605 in this embodiment has a substantially triangular (inverted triangle) shape with the bottom 652 as one vertex.

[0059] Similarly to the first embodiment, the step portion 606 in this embodiment is formed across the entire width of the connecting portion 604 in the width direction (Z' direction), and has a rising point 661 on the second main surface 642. The step portion 606 is formed rising at a substantially right angle from the rising point 661, and is connected to a support portion (not shown) while maintaining a predetermined height.

[0060] In this embodiment, the rising point 661 is provided on the second main surface 642 within the range of the region R5 facing the recess 605, and at the intersection of an extension line of the inner wall surface 651b and the second main surface 642. When the inner wall surface 651b has an arc shape rather than a straight line, the rising point 661 is provided at the intersection of the second main surface 642 and an extension line of a straight line connecting both ends (one end on the bottom 652 side and the other end on the opening side) of the inclined inner wall surface 651b as viewed from the width direction (Z' direction) of the connecting portion 4.

[0061] In this embodiment, the rising point 661 is provided at the intersection of an extension line of the inner wall surface 651b and the second main surface 642, but may be provided at the intersection of an extension line of the inner wall surface 651a and the second main surface 642. In addition, when the inner wall surface 651a has an arc shape instead of a straight line, the rising point 661 may be provided at the intersection of the second main surface 642 and an extension line of a straight line connecting both ends (one end on the bottom 652 side and the other end on the opening side) of the inclined inner wall surface 651a as viewed from the width direction (Z' direction) of the connecting portion 4.

[0062] In addition, the piezoelectric vibrating piece aggregate wafer 1 of the present invention is preferably configured such that the rising point 61 where the step portion 6 rises from the second main surface 42 of the connecting portion 4 is located at a position overlapping with the bottom portion 52 of the recess 5 as viewed from the second main surface 42, or on the piezoelectric vibrating piece side from the bottom portion 52. With such a configuration, the outer shape of the broken end portion 24 of the obtained quartz crystal vibrating piece 20 becomes a bent shape as shown in Fig. 11, and when used as a piezoelectric device, it is possible to prevent the broken end portion 24 from being broken by impact and becoming a foreign object. In addition, the connecting portion 4 can have a more appropriate strength.

[0063] Furthermore, the piezoelectric vibrating piece aggregate wafer 1 of the present invention is preferably configured such that, when viewed from the width direction (Z' direction) of the connecting portion 4, the rising point 61 is located at the intersection of an extension line passing through both ends of the inclined inner wall surface 51a or inner wall surface 51b and the second main surface 42 of the connecting portion 4. With such a configuration, the connecting portion 4 can be made to have a more appropriate strength. Furthermore, the shape of the fracture surface 23 of the quartz crystal vibrating piece 20 can be more reliably controlled.

[0064] It should be noted that the present invention is not limited to the configurations of the above-described embodiments, and many other embodiments can be obtained. For example, the piezoelectric vibrating piece aggregate wafer 1 of the present invention, the quartz vibrating piece portion 2, support portion 3, and connecting portion 4 that constitute the piezoelectric vibrating piece aggregate wafer 1, and the quartz vibrating piece 20 obtained from the piezoelectric vibrating piece aggregate wafer 1 are configured to be made of quartz, but they may also be made of a material known as a piezoelectric vibrating piece other than quartz, such as ceramic.

[0065] In the present embodiment, the piezoelectric vibrating piece is described as a rectangular AT-cut quartz crystal vibrating piece (quartz crystal vibrating piece 2), but is not limited to this configuration. For example, the piezoelectric vibrating piece may be a quartz crystal plate with a different cut angle such as an SC cut, a Z-cut quartz crystal plate, or a tuning fork-shaped quartz crystal plate.

[0066] The embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present invention is not interpreted solely by the above-described embodiments, but is defined by the claims. Also, all modifications within the scope and meaning equivalent to the claims are included. [Industrial Applicability]

[0067] INDUSTRIAL APPLICABILITY The piezoelectric vibrating piece aggregate wafer and the piezoelectric vibrating piece of the present invention can be used in the industries of manufacturing and selling piezoelectric devices. [Explanation of symbols]

[0068] 1...Piezoelectric vibrating piece assembly wafer 2...Crystal vibrating piece 20...Crystal vibrating piece 21…First main surface 22…Second main surface 3...Support part 31…Outer frame 32…Inner frame 32a…Vertical inner frame section 32b…Horizontal inner frame section 33…Support inner area 4...Connection part 41…First main surface 42…Second main surface 5…Recess 51a, 51b...Inner wall surface 52...bottom 6…Step 61…Start point

Claims

1. A piezoelectric vibrating piece aggregate wafer having a plurality of piezoelectric vibrating pieces, a support portion supporting the piezoelectric vibrating pieces, and a connecting portion connecting each of the piezoelectric vibrating pieces to the support portion, The connecting portion is The connecting portion has a first main surface perpendicular to a thickness direction thereof and a second main surface which is a rear surface of the connecting portion as viewed from the first main surface, The first main surface has a recess that is recessed in the thickness direction, The second main surface has a step portion that rises in a convex direction from a position facing the concave portion. Piezoelectric vibrating piece assembly wafer.

2. The height of the step portion from the second main surface is equal to or greater than the thickness from the bottom of the recess to the second main surface.

2. The piezoelectric vibrating piece aggregate wafer according to claim 1.

3. The recess has a substantially triangular shape in cross section with the bottom of the recess as one vertex.

2. The piezoelectric vibrating piece aggregate wafer according to claim 1.

4. A piezoelectric vibrating piece aggregate wafer according to any one of claims 1 to 3, Piezoelectric vibrating piece.

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