Piezoelectric vibrating piece assembly wafer and piezoelectric vibrating piece

Abstract

To provide a piezoelectric vibrating piece assembly wafer capable of suppressing a piezoelectric vibrating piece from falling off from a support part during manufacturing of the piezoelectric vibrating piece, and provide the piezoelectric vibrating piece obtained from the piezoelectric vibrating piece assembly wafer.SOLUTION: A piezoelectric vibrating piece assembly wafer 1 includes: a plurality of piezoelectric vibrating piece parts 2; a support part 3 that supports the piezoelectric vibrating piece part 2; and a coupling part 4 that couples the individual piezoelectric vibrating piece parts 2 and the support part 3. A first connecting part 4A includes: a main surface 21A orthogonal to a thickness direction thereof; a concave part 5A which is provided on the main surface 21A and is concave in a thickness direction and whose longitudinal direction is a width direction of the first connecting part 4A; a first narrow part 46A and a second narrow part 47A which are provided so as to sandwich the concave part 5A from both sides of the longitudinal direction of the concave part 5A; and a reinforcing part 48A which is provided on at least one end surface in the width direction. The reinforcing part 48A has a shape that gradually becomes thin toward an end part in the width direction of the first connecting part 4A.SELECTED DRAWING: Figure 3

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 to a piezoelectric vibrating piece obtained from the piezoelectric vibrating piece aggregate wafer. [Background technology]

[0002] A known method for manufacturing piezoelectric vibrating reeds used in piezoelectric devices is to etch a quartz crystal wafer to obtain a large number of piezoelectric vibrating reeds. For efficiency, the large number of piezoelectric vibrating reeds are supported by a support member via connecting parts, and then the individual piezoelectric vibrating reeds are broken off from 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] Jipkaihei 03-039922 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, piezoelectric vibrating reeds compatible with higher frequencies have been used in communication modules and the like. For example, when an AT-cut quartz crystal vibrating reed is used as the piezoelectric vibrating reed, the thickness of the piezoelectric vibrating reed tends to become thinner as the frequency increases. However, as the thickness of the piezoelectric vibrating reed decreases, when a technique for providing slits in the connecting portions as described in Patent Document 1 is applied, the strength of the connecting portions where the slits are formed decreases, and the connecting portions may break during manufacturing, causing the piezoelectric vibrating reed to fall off 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 aggregate wafer having a plurality of piezoelectric vibrating piece portions, a support portion that supports the piezoelectric vibrating piece portions, and connecting portions that connect each of the piezoelectric vibrating piece portions to the support portion, wherein the connecting portions have a main surface that is perpendicular to its thickness direction, a recess that is provided on the main surface and is concave in the thickness direction, with the width direction of the connecting portion as its longitudinal direction, a first narrow portion and a second narrow portion that are provided on both sides of the longitudinal direction of the recess so as to sandwich the recess, and a reinforcing portion that is provided on at least one end face in the width direction of the connecting portion, and the reinforcing portion is characterized in that the piezoelectric vibrating piece aggregate wafer has a shape that gradually becomes thinner toward the width direction end of the connecting portion.

[0008] That is, the piezoelectric vibrating piece aggregate wafer of the present invention has a recess whose longitudinal direction is the width direction of the connecting portion, a first narrow portion and a second narrow portion provided on both sides of the longitudinal direction of the recess so as to sandwich the recess, and a reinforcing portion provided on at least one end of the connecting portion in the width direction. With this configuration, the strength of the connecting portion provided with the recess (slit) is improved, and it is possible to prevent the connecting portion from breaking during manufacturing and causing the piezoelectric vibrating piece to fall off the support portion.

[0009] In addition, the other end face of the connecting portion, which is opposite the one end face in the width direction of the connecting portion, and the outer peripheral surface of the piezoelectric vibrating reed may be formed in a continuous straight line in a plan view, and the connecting portion may have a widening portion that gradually widens from the piezoelectric vibrating reed side to the support portion side. With this configuration, even though the connecting portion is intended to break along the recess, the risk of breakage near the connection between the connecting portion and the support portion can be reduced. In other words, the fracture shape and external shape of the piezoelectric vibrating reed can be controlled.

[0010] The recess may have a bottom and have a generally triangular shape with the bottom as one vertex when viewed in a cross section in a short direction perpendicular to the long direction of the recess. With this configuration, stress can be concentrated at the bottom of the recess when breaking off the piezoelectric vibrating reed, making it possible to more reliably break the connecting portion along the recess. In other words, the shape of the fracture surface of the piezoelectric vibrating reed can be more reliably controlled.

[0011] The present invention is also characterized by 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 shape and appearance shape. [Effects of the Invention]

[0012] 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 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. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is a plan view of a piezoelectric vibrating piece aggregate wafer. [Figure 2] FIG. 3 is a plan view of a first main surface side of a piezoelectric vibrating piece in a unit area. [Figure 3] FIG. 3 is an enlarged plan view of a region near a first connecting portion in FIG. 2. [Figure 4] AA cross section in FIG. 3. [Figure 5] BB cross section in FIG. 3. [Figure 6] FIG. 10 is a cross-sectional view corresponding to the BB cross-sectional view according to the second embodiment. [Figure 7] FIG. 11 is a cross-sectional view corresponding to the cross-sectional view taken along line BB according to the third embodiment. [Figure 8] FIG. 10 is a plan view corresponding to an enlarged plan view of a region near a first connecting portion according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] 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 resonator element. The AT-cut quartz crystal resonator element and the Z', X, and Y' directions will be described in detail in later paragraphs.

[0015] FIG. 1 is a plan view of a piezoelectric vibrating piece aggregate wafer 1. FIG. The piezoelectric vibrating piece aggregate wafer 1 according to this embodiment (first embodiment) is entirely formed into a thin plate shape from AT-cut quartz. The piezoelectric vibrating piece aggregate wafer 1 has a plurality of substantially rectangular piezoelectric vibrating piece portions 2, a support portion 3 that holds the plurality of piezoelectric vibrating piece portions 2, and a connecting portion 4 that connects the piezoelectric vibrating piece portions 2 and the support portion 3.

[0016] The support portion 3 in this embodiment has a uniform thickness and includes a rectangular outer frame portion 31 formed so as to surround the periphery (four sides) of the piezoelectric vibrating reed portion 2, and a plurality of inner frame portions 32 formed in a lattice pattern within the area surrounded by the outer frame portion 31. The outer frame portion 31 and the inner frame portion 32 are integrally formed.

[0017] In this embodiment, the multiple inner frame portions 32 are in a lattice pattern extending in the Z' and X directions, with multiple vertical inner frame portions 32a extending in the X direction arranged parallel to and at equal intervals from one another, and multiple horizontal inner frame portions 32b extending in the Z' direction arranged parallel to and at equal intervals from one another. The vertical inner frame portions 32a and the horizontal inner frame portions 32b are formed so as to intersect at right angles, and multiple through-holes 33 that are rectangular in plan view and surrounded by the vertical inner frame portions 32a and the horizontal inner frame portions 32b are formed.

[0018] The through portions 33 are through holes that penetrate the piezoelectric vibrating piece aggregate wafer 1 in the thickness direction (Y' direction), and one piezoelectric vibrating piece 2 is disposed in each of the plurality of through portions 33. At this time, the piezoelectric vibrating piece 2 is held on the support part 3 by the connecting parts 4. In this embodiment, the piezoelectric vibrating piece 2 is connected to and held by the horizontal inner frame part 32b by the connecting parts 4.

[0019] Therefore, in the piezoelectric vibrating piece aggregate wafer 1, multiple unit areas 10 each consisting of a vertical inner frame portion 32a, a horizontal inner frame portion 32b, a through portion 33, one piezoelectric vibrating piece portion 2 arranged within the through portion 33, and a connecting portion 4 are formed in a matrix.

[0020] FIG. 2 is a plan view of the first main surface 21 side of the piezoelectric vibrating piece 2 in the unit region 10. As shown in FIG. The piezoelectric vibrating piece 2 in this embodiment is an AT-cut quartz crystal vibrating piece. The piezoelectric vibrating piece 2 has a first main surface 21 perpendicular to the thickness direction (Y' direction) of the piezoelectric vibrating piece 2 and a second main surface (not shown) corresponding to the backside of the first main surface 21. The piezoelectric vibrating piece 2 has a rectangular shape with long and short sides when viewed from the first main surface 21 side, and is connected to the lateral inner frame portion 32b near both ends of one of the short sides via connecting portions 4 (first connecting portion 4A, second connecting portion 4B). The piezoelectric vibrating piece 2 measures, for example, 1.9 mm × 1.2 mm. Note that AT-cut is a processing technique in which 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: the electrical axis (X-axis), the mechanical axis (Y-axis), and the optical axis (Z-axis). In an AT-cut quartz crystal plate, the X-axis coincides with the crystal axis of the quartz crystal. The Y' and Z' axes correspond to axes tilted 35°15' from the Y and Z crystal axes of the quartz. The Y' and Z' axis directions correspond to the cutting direction when cutting out an AT-cut quartz plate.

[0021] For example, the piezoelectric vibrating piece aggregate wafer 1 and the piezoelectric vibrating pieces 2 can be fabricated by forming a metal pattern on an AT-cut quartz crystal plate using photolithography and then etching the AT-cut quartz crystal with the metal pattern to form the outer shapes of the support 3, the piezoelectric vibrating pieces 2, and the connecting pieces 4. The step of adjusting the thickness of the piezoelectric vibrating pieces 2 by etching and the step of forming the outer shapes of the support 3, the piezoelectric vibrating pieces 2, and the connecting pieces 4 may be performed separately. After forming the outer shapes of each part, electrode patterns (not shown) can be formed by sputtering and photolithography. For example, the electrode patterns can be formed by forming excitation electrodes and extraction electrodes on the piezoelectric vibrating pieces 2, forming connection electrodes connected to the extraction electrodes on the connecting pieces 4, and forming measurement terminal electrodes connected to the connection electrodes on the support 3 (horizontal inner frame portion 32b).

[0022] In this embodiment, the piezoelectric vibrating reed 2 has a flat first principal surface 21 and a flat second principal surface, but is not limited to this configuration. For example, the piezoelectric vibrating reed 2 may have a mesa structure in which the center of at least one of the first principal surface 21 and the second principal surface is convex. Alternatively, for example, the piezoelectric vibrating reed 2 may have an inverted mesa structure in which the center of at least one of the first principal surface 21 and the second principal surface is concave.

[0023] In addition, in this embodiment, the piezoelectric vibrating reed 2 is configured to be connected to the horizontal inner frame portion 32b via connecting portions 4 (first connecting portion 4A, second connecting portion 4B) near both ends of one short side, but this configuration is not limited to this. For example, the connection position with the connecting portion 4 (first connecting portion 4A, second connecting portion 4B) may be near the center of one short side or one long side. Furthermore, the piezoelectric vibrating reed 2 may be configured to be connected to the horizontal inner frame portion 32b via one or three or more connecting portions 4. Furthermore, the piezoelectric vibrating reed 2 may be configured to be connected to the outer frame portion 31 or the vertical inner frame portion 32a.

[0024] The connecting portion 4 is formed integrally with the support portion 3 and the piezoelectric vibrating reed 2, and connects the support portion 3 and the piezoelectric vibrating reed 2. In this embodiment, two connecting portions 4 are provided for one piezoelectric vibrating reed 2 on one short side of the piezoelectric vibrating reed 2: a first connecting portion 4A provided near the end on the -Z' side and a second connecting portion 4B provided near the end on the +Z' side. The first and second connecting portions 4A and 4B are thin plate-shaped with the Z' direction as the width direction, and have first main surfaces 41A and 41B perpendicular to the thickness direction (Y' direction) of the first and second connecting portions 4A and 4B, and second main surfaces 42A and 42B corresponding to the back surfaces of the first main surfaces 41A and 41B. In this embodiment, the first and second connecting portions 4A and 4B are formed so that the widthwise length is shorter than the short side of the piezoelectric vibrating reed 2. Furthermore, the first and second connecting portions 4A and 4B of this embodiment are provided for one piezoelectric vibrating piece 2 so as to connect the piezoelectric vibrating piece 2 to the horizontal inner frame portion 32b near both ends of one short side of the piezoelectric vibrating piece 2. That is, in the unit area 10 of this embodiment, two connecting portions 4 (the first connecting portion 4A and the second connecting portion 4B) are provided, and an opening 34 is formed by the piezoelectric vibrating piece 2, the first connecting portion 4A, the second connecting portion 4B, and the horizontal inner frame portion 32b.

[0025] 3 is an enlarged plan view of the first connecting portion vicinity region 11 in FIG. 2, FIG. 4 is a cross-sectional view taken along line AA in FIG. 3, and FIG. 5 is a cross-sectional view taken along line BB in FIG. In this embodiment, the first connecting portion 4A is the connecting portion provided on the -Z' side of the two connecting portions 4 (first connecting portion 4A, second connecting portion 4B). In a plan view (viewed from the Y' direction), the first connecting portion 4A has an end face 43A (the other end face) on the -Z' side in the width direction of the first connecting portion 4A and one end face (the end face 22 on the -Z' side) of the outer circumferential surface of the piezoelectric vibrating reed 2 formed in a continuous straight line. Furthermore, the first connecting portion 4A has an end face 44A (one end face) on the +Z' side in the width direction of the first connecting portion 4A formed parallel to the X direction from the piezoelectric vibrating reed 2 and then inclined at a certain angle with respect to the X direction toward the support portion 3 (the horizontal inner frame portion 32b). That is, the first connecting portion 4A has a widening portion 45A whose width gradually increases from the piezoelectric vibrating reed 2 side toward the support portion 3 side. Therefore, the width of the first connecting portion 4A in the X direction near the end portion on the piezoelectric vibrating piece 2 side is larger than the width of the first connecting portion 4A in the X direction near the end portion on the support portion 3 side. For example, when the piezoelectric vibrating piece 2 has a size of 1.9 mm × 1.2 mm, the width of the connecting portion 4 in the X direction near the end portion on the piezoelectric vibrating piece 2 side can be approximately 250 μm, and the width in the X direction near the end portion on the support portion 3 side can be approximately 300 μm.

[0026] The first connecting portion 4A has, on the first main surface 41A, a bottomed recess 5A that is recessed in the thickness direction and has the width direction (Z' direction) of the first connecting portion 4A as its longitudinal direction, and a first narrow width portion 46A and a second narrow width portion 47A that are provided to sandwich the recess 5A from both sides in the width direction (Z' direction) of the first connecting portion 4A. In this embodiment, the first narrow width portion 46A and the second narrow width portion 47A are formed to have the same width (length in the width direction of the first connecting portion 4A). Furthermore, the combined length of the width of the first narrow width portion 46A and the width of the second narrow width portion 47A is formed to be shorter than the longitudinal length of the recess 5A. More specifically, the combined length of the width 1L of the first narrow portion 46A and the width 2L of the second narrow portion 47A is 50% or less, preferably 30% or less, and more preferably 10% or less, of the width 3L of the recess 5A provided in the first connecting portion 4A. For example, if the width of the first connecting portion 4A near the end portion on the piezoelectric vibrating piece 2 side is approximately 250 μm, the widths of the first narrow portion 46A and the second narrow portion 47A can be approximately 5 μm.

[0027] Moreover, the first connecting portion 4A in this embodiment has a reinforcing portion 48A formed along one end surface 44A (the end surface on the +Z' side) in the width direction of the connecting portion 4. The reinforcing portion 48A in this embodiment is an inclined surface that forms a predetermined angle with the second main surface 42A in the thickness direction of the first connecting portion 4A. That is, the first connecting portion 4A in this embodiment is formed so that its width gradually increases from the first main surface 41A to the second main surface 42A. Moreover, the reinforcing portion 48A is provided at least on an extension line of the recess 5A in the Z' direction in a plan view.

[0028] The recess 5A is provided on the first main surface 41A of the first connecting portion 4A near the end portion on the piezoelectric vibrating reed 2 side. The recess 5A is formed with the width direction (Z' direction) of the first connecting portion 4A as the longitudinal direction, and both ends in the longitudinal direction are closed by the first narrow width portion 46A and the second narrow width portion 47A. In this embodiment, both ends (short sides) in the longitudinal direction of the recess 5A are formed to be approximately curved in a plan view. Furthermore, the recess 5A in this embodiment has long sides formed parallel to the Z' direction, and of the two long sides, the long side on the +X side is located on an extension line of the short side on the -X side of the piezoelectric vibrating reed 2.

[0029] The recess 5A is a bottomed slit having an opening in the first main surface 41A of the first connecting portion 4A. The recess 5A has inner circumferential surfaces at both ends in the longitudinal direction, at least one of which is an inclined surface inclined inward at an angle with respect to the Y′ direction. In this embodiment, the first inner circumferential surface 51A (inner circumferential surface on the −Z′ side) formed by the first narrow width portion 46A is formed as an inclined surface inclined inward toward the recess 5A, and the fourth inner circumferential surface 54A (inner circumferential surface on the +Z′ side) formed by the second narrow width portion 47A is formed parallel to the Y′ direction. The recess 5A has inner circumferential surfaces at both ends in the lateral direction, at least one of which is an inclined surface inclined inward at an angle with respect to the Y′ direction. In this embodiment, both of the inner circumferential surfaces (second inner circumferential surface 52A, third inner circumferential surface 53A) of both ends in the lateral direction are formed as inclined surfaces inclined inward toward the recess 5A. The inclination of each inner peripheral surface may be linear in cross section or may have a predetermined curvature. That is, each inner peripheral surface of the recess 5A may be curved in cross section. Furthermore, the recess 5A of this embodiment is formed in a substantially triangular shape with the bottom 55A as the vertex in a cross section in the short side direction. The bottom 55A may be substantially curved as shown in FIG. 4 or may have an acute angle.

[0030] Furthermore, the depth of the recess 5A (the length in the Y' direction from the opening of the recess 5A to the bottom 55A) is preferably about half the thickness of the first connecting portion 4A. More specifically, the depth of the recess 5A is preferably 40 to 60% of the thickness of the first connecting portion 4A.

[0031] Further, the second connecting portion 4B is also provided with a recess 5B at the same position as the first connecting portion 4A. The recess 5B preferably has the same shape as the recess 5A.

[0032] Such recesses 5A and 5B can be formed simultaneously when the outer shapes of the support portion 3, the piezoelectric vibrating reed portion 2, and the connecting portion 4 are formed by etching.

[0033] By pressing the piezoelectric vibrating pieces 2 in the Y direction while fixing the support part 3 with a jig or the like to such a piezoelectric vibrating piece aggregate wafer 1, the piezoelectric vibrating pieces 2 are broken off from the support part 3 to become individual piezoelectric vibrating pieces. At this time, the piezoelectric vibrating pieces 2 are broken off from the support part 3 along the shapes of the recesses 5A and 5B in the first and second connecting parts 4A and 4B.

[0034] With the above configuration, it is possible to provide a piezoelectric vibrating piece aggregate wafer that can prevent the piezoelectric vibrating pieces from falling off the support portion during the manufacturing process of the piezoelectric vibrating pieces. The piezoelectric vibrating piece aggregate wafer 1 of the present invention has a recess 5A whose longitudinal direction is the width direction of the first connecting portion 4A, a first narrow portion 46A and a second narrow portion 47A provided on both longitudinal sides of the recess 5A so as to sandwich the recess, and a reinforcing portion 48A provided on one end face in the width direction of the first connecting portion 4A. This configuration allows the appearance of the folded portion of the piezoelectric vibrating piece obtained by folding it off from the piezoelectric vibrating piece aggregate wafer 1 to be shaped to match the recess 5A. Furthermore, with a conventional configuration, vibrations of the piezoelectric vibrating piece aggregate wafer 1 during manufacturing could cause the first connecting portion 4A to break, causing the piezoelectric vibrating piece portion 2 to unintentionally break off from the support portion 3 and fall off. However, the reinforcing portion 48A improves the strength of the first connecting portion 4A, thereby preventing the piezoelectric vibrating piece portion 2 from falling off during manufacturing. In particular, since the recess 5A is closed by the first narrow portion 46A and the second narrow portion 47A, the first connecting portion 4A can be made resistant to vibrations in the horizontal direction (Z' direction). On the other hand, since the first connecting portion 4A is made vulnerable to forces in the vertical direction (Y' direction) by the recess 5A, when the piezoelectric vibrating piece 2 is broken off, it is possible to prevent the first connecting portion 4A from being broken off at a location other than the recess 5A, and a piezoelectric vibrating piece having a desired appearance at the broken part can be obtained.

[0035] Furthermore, the reinforcing portion 48A is formed to have an inclination that forms a predetermined angle in the thickness direction. That is, the first connecting portion 4A in this embodiment is formed to gradually widen from the first main surface 41A to the second main surface 42A. With this configuration, particularly when the piezoelectric vibrating piece 2 is pressed from the first main surface 41A side when being broken off, the strength of the first main surface 41A side, to which more stress is applied, can be weakened while the strength of the second main surface 42A side can be increased. Therefore, it is possible to both suppress the piezoelectric vibrating piece 2 from falling off during manufacturing and suppress the occurrence of breaking defects caused by the piezoelectric vibrating piece 2 being broken off at a location in the first connecting portion 4A other than the recess 5A when being broken off.

[0036] Furthermore, the other end surface 43A in the width direction of the first connecting portion 4A and one end surface 22 of the piezoelectric vibrating piece 2 are formed in a continuous straight line in a plan view, and the first connecting portion 4A has a widening portion 45A that gradually widens from the piezoelectric vibrating piece 2 side toward the support portion 3 (horizontal inner frame portion 32b). This configuration reduces the risk of the first connecting portion 4A breaking near the connection with the horizontal inner frame portion 32b, even though the first connecting portion 4A is intended to break along the recess 5A. More specifically, the force transmitted from the piezoelectric vibrating piece 2 to the first connecting portion 4A during breaking is applied as stress to each point. At this time, stress is more concentrated at points with smaller angles in a plan view. When the stress applied to a certain point exceeds a certain level, breakage occurs starting from that point. Here, if the first connecting portion 4A does not have the widening portion 45A, the end of the first connecting portion 4A facing the piezoelectric vibrating reed 2 and the end facing the horizontal inner frame portion 32b would each have the same angle (90 degrees). Since equal stress is applied to each corner, fracture may occur at the end facing the horizontal inner frame portion 32b. However, with the first connecting portion 4A having the widening portion 45A of the present invention, the smallest angle is the corner formed by the short side of the piezoelectric vibrating reed 2 and one end face 44A in the width direction of the first connecting portion 4A, i.e., the corner closest to the recess 5A. As described above, stress is concentrated at corners with smaller angles, so stress is more concentrated at the corner closest to the recess 5A, making fracture more likely. Therefore, fracture can occur at a desired position in the first connecting portion 4A when breaking, and the fracture shape and external appearance of the resulting piezoelectric vibrating reed can be controlled.

[0037] Furthermore, one end face 44A (the end face on the +Z' side) of the first connecting portion 4A in the width direction is formed parallel to the X direction from the piezoelectric vibrating piece 2, and then inclined at a certain angle with respect to the X direction toward the support portion 3 (the horizontal inner frame portion 32b). With this configuration, the following angles are formed in the one end face 44A in a plan view: a corner formed by the short side of the piezoelectric vibrating piece 2 and the one end face 44A, an end point of the widened portion 45A of the one end face 44A, and a corner formed by the one end face 44A (widened portion 45A) and the horizontal inner frame portion 32b. In other words, stress acting on the end face of the first connecting portion 4A on the horizontal inner frame portion 32b side can be dispersed to two locations, further increasing the strength of the end face on the horizontal inner frame portion 32b side, making it possible to generate fracture at the corner formed by the short side of the piezoelectric vibrating piece 2 and the one end face 44A.

[0038] Furthermore, the recess 5A has a bottom 55A and is configured to have a substantially triangular shape with the bottom 55A as one vertex when viewed in a cross section in the short direction of the recess 5A. With this configuration, when the piezoelectric vibrating piece 2 is broken off, the applied stress is concentrated on the bottom 55A, and the first connecting portion 4A can be broken more reliably along the recess 5A. In other words, the shape of the fracture surface of the resulting piezoelectric vibrating piece can be more reliably controlled.

[0039] Furthermore, the combined length of the width 1L of the first narrow portion 46A and the width 2L of the second narrow portion 47A is 50% or less, preferably 30% or less, and more preferably 10% or less, of the width 3L of the recess 5A provided in the first connecting portion 4A. With this configuration, the strength of the recess 5A against forces in the vertical direction (Y' direction) can be made to be a strength that is more appropriate for balancing between preventing the piezoelectric vibrating piece 2 from falling off during manufacturing and breaking off the piezoelectric vibrating piece 2.

[0040] Furthermore, the depth of the recess 5A is preferably 40 to 60% of the thickness of the first connecting portion 4A. With this configuration, the strength of the recess 5A against forces in the vertical direction (Y' direction) can be made to be a strength that is more suitable for balancing between preventing the piezoelectric vibrating piece 2 from falling off during manufacturing and breaking off the piezoelectric vibrating piece 2.

[0041] The present invention is not limited to the configurations of the above-described embodiments, and many other embodiments can be obtained. FIG. 6 is a cross-sectional view corresponding to the BB cross-sectional view according to the second embodiment, and FIG. 7 is a cross-sectional view corresponding to the BB cross-sectional view according to the third embodiment. For example, in the first embodiment, in recess 5A, first inner circumferential surface 51A (inner circumferential surface on the -Z' side) formed by first narrow width portion 46A is formed as an inclined surface that slopes toward the inside of recess 5A, and fourth inner circumferential surface 54A (inner circumferential surface on the +Z' side) formed by second narrow width portion 47A is formed parallel to the Y' direction, but fourth inner circumferential surface 54A (inner circumferential surface on the +Z' side) may be formed at an angle with respect to the Y' direction. For example, as shown in FIG. 6, fourth inner circumferential surface 541A may be formed so as to enter second narrow width portion 47A, or fourth inner circumferential surface 542A may be formed so as to protrude toward the inner circumferential side as shown in FIG.

[0042] Also, as shown in Figure 6, the fourth inner surface 541A and the other end face 431A (the end face on the -Z' side) in the width direction of the connecting portion 4 may be formed at the same angle with respect to the Y' direction, and the other end face 431A (the end face on the -Z' side) in the width direction of the connecting portion 4 may be formed so as to fit into the first narrow portion 46A.

[0043] FIG. 8 is a plan view corresponding to an enlarged plan view of the first connecting portion vicinity region 11 according to the fourth embodiment. Furthermore, in the first embodiment, the first connecting portion 4A is configured to have one recess 5A. However, the first connecting portion 4A may be configured to have multiple recesses. For example, as shown in FIG. 7, the first connecting portion 4A may be configured to have two recesses 6A and 7A. In this case, it is preferable that the recess 7A is provided on an extension line of the recess 6A in the longitudinal direction (Z′ direction). Similarly, it is preferable that the recess 6A is provided on an extension line of the recess 7A in the longitudinal direction (Z′ direction). In this configuration, a first narrow portion 461A and a third narrow portion 49A are provided to sandwich the recess 7A from both ends, and a second narrow portion 471A and a third narrow portion 49A are provided to sandwich the recess 6A from both ends. In other words, the third narrow portion 49A is provided between the recess 6A and the recess 7A. Although such a configuration can achieve the same effects as the present embodiment, it is more preferable that the first connecting portion 4A has one recess 5A, as in the first embodiment. If the first connecting portion 4A has one recess 5A, the strength (fragility) of the recess 5A of the first connecting portion 4A can be made suitable for breaking off the piezoelectric vibrating reed 2.

[0044] In the first embodiment, a rectangular AT-cut quartz crystal vibrating piece is used as the piezoelectric vibrating piece 2, but the present invention is not limited to this configuration. For example, the piezoelectric vibrating piece 2 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.

[0045] Furthermore, in each of the above-described embodiments, both main surfaces of the piezoelectric vibrating reed 2 are smooth, but a part of both main surfaces or a part of one of the main surfaces of the piezoelectric vibrating reed 2 may be formed in a convex or concave shape. That is, the piezoelectric vibrating reed 2 may have a mesa shape or an inverted mesa shape.

[0046] The embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present invention should not be interpreted solely by the above-described embodiments, but should be defined by the claims. Furthermore, all modifications within the scope and meaning equivalent to the claims are included. [Industrial Applicability]

[0047] The piezoelectric vibrating piece aggregate wafer and the piezoelectric vibrating piece of the present invention can be used in the industry of manufacturing and selling piezoelectric devices. [Explanation of symbols]

[0048] 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 33...Penetration section 4...Connection part 41A...First principal surface 42A...Second principal surface 43A...other end face 44A...One end face 45A...widened section 46A…1st narrow part 47A…Second narrow part 48A...Reinforcement section 5A, 6A, 7A...recess 51A…First inner circumferential surface 52A…Second inner peripheral surface 53A…Third inner peripheral surface 54A…4th inner peripheral surface 55A…Bottom

Claims

1. A piezoelectric vibrating piece aggregate wafer having a plurality of piezoelectric vibrating piece portions, a support portion that supports the piezoelectric vibrating piece portions, and a connecting portion that connects each of the piezoelectric vibrating piece portions to the support portion, The connecting portion is a main surface perpendicular to the thickness direction; a recess provided on the main surface, recessed in the thickness direction, and having a longitudinal direction that is the width direction of the connecting portion; a first narrow portion and a second narrow portion provided on both sides of the recess in a longitudinal direction so as to sandwich the recess; a reinforcing portion provided on at least one end surface in the width direction of the connecting portion, The reinforcing portion has a shape that gradually becomes thinner toward the end portion in the width direction of the connecting portion. Piezoelectric vibrating strip assembly wafer.

2. the other end face, which is opposite to the one end face in the width direction of the connecting portion, and the outer circumferential surface of the piezoelectric vibrating reed are formed in a continuous linear shape in a plan view, The connecting portion has a widening portion that gradually widens from the piezoelectric vibrating piece side to the support portion side. The piezoelectric vibrating piece aggregate wafer according to claim 1 .

3. The recess has a bottom and has a substantially triangular shape with the bottom as one vertex when viewed in a cross section in a short direction perpendicular to the long direction of the recess. 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 reed.

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