JP2015173366A - Piezoelectric vibrating piece and piezoelectric device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric vibration piece which inhibits increase in a crystal impedance (CI) value, and to provide a piezoelectric device including the piezoelectric vibration piece.SOLUTION: A piezoelectric vibration piece 130 includes: a vibration part 131 where excitation electrodes 136 are formed on a first main surface 139a and a second main surface 139b opposite to the first main surface, the vibration part 131 vibrating at a predetermined frequency; a peripheral part 132 which encloses the vibration part contacting with the vibration part and is formed recessed from the surface of the vibration part; a recessed part 133 which encloses the peripheral part contacting with the peripheral part and is formed recessed from a surface of the peripheral part; a frame part 134 which encloses the recessed part contacting with the recessed part and is formed so as to have a thickness equal to or larger than a thickness of the vibration part; and a connection part 135 which is formed at parts of the peripheral part and the recessed part, extends from the vibration part to the frame part to connect the vibration part with the frame part, and is formed so as to have a thickness equal to the thickness of the vibration part. In the piezoelectric vibration piece, extraction electrodes 137 are led out from the excitation electrodes to the frame part through the connection part.

Description

  The present invention relates to a piezoelectric vibrating piece in which an increase in crystal impedance (CI) value is suppressed and a piezoelectric device including the piezoelectric vibrating piece.

  Piezoelectric devices are used in various fields such as electronic equipment, and the downsizing is required with the downsizing of watches and computers. In addition, a large number of piezoelectric devices may be manufactured at once by forming a plurality of piezoelectric devices on a wafer in order to improve the manufacturing process efficiency. Such a piezoelectric device is formed by a piezoelectric vibrating piece and a base plate and a lid plate that sandwich the piezoelectric vibrating piece.

  For example, Patent Document 1 discloses a piezoelectric vibrating piece including a vibrating portion that vibrates at a predetermined frequency and a frame portion that surrounds the vibrating portion and is supported by a base plate and a lid plate. A through-hole penetrating the piezoelectric vibrating piece is provided between the vibration part and the frame part, and vibration energy generated in the vibration part is prevented from escaping to the frame part. Therefore, the piezoelectric vibrating piece has excellent vibration characteristics.

JP 2012-147148 A

  However, in patent document 1, in order to form a penetration part by what is called wet etching, it is necessary to take the width | variety of the penetration part for etching widely. For this reason, when the vibration part is formed from a predetermined size, the area is narrowed, and the crystal impedance (CI) value is increased due to the area of the small vibration part.

  An object of the present invention is to provide a piezoelectric vibrating piece in which an increase in crystal impedance (CI) value is suppressed and a piezoelectric device including the piezoelectric vibrating piece.

  The piezoelectric vibrating piece according to the first aspect vibrates at a predetermined frequency, and is in contact with the vibrating unit, the vibrating unit having excitation electrodes formed on the first main surface and the second main surface opposite to the first main surface, respectively. And surrounding the vibration part, formed thinner than the thickness of the vibration part, and formed in contact with the peripheral part, the first main surface side and the second main surface side being recessed from the surface of the vibration part, respectively. A recess that surrounds the periphery and is formed thinner than the periphery and is recessed from the surface of the periphery on the first main surface side and the second main surface side, and around the recess in contact with the recess And is formed in a part of the peripheral part and the concave part, extending from the vibration part to the frame part, and connecting the vibration part and the frame part to form the vibration part. The first main surface side and the second main surface side are formed with the same thickness as the thickness of the vibration portion and have a connection portion having no step and a step portion. . Further, in the piezoelectric vibrating piece, the extraction electrode is drawn from each excitation electrode to the frame portion via the connecting portion.

  The piezoelectric vibrating piece according to the second aspect is the lead extracted from the excitation electrode formed on the first main surface, in the first aspect, a castellation that is recessed inside the frame is formed on a part of the outer side surface of the frame. The electrode is drawn from the first main surface of the frame portion to the second main surface of the frame portion through castellation.

  The piezoelectric vibrating piece according to the third aspect vibrates at a predetermined frequency and is in contact with the vibrating portion, the vibrating portion having the first principal surface and the second principal surface opposite to the first principal surface, each having an excitation electrode. And surrounding the vibration part, formed thinner than the thickness of the vibration part, and formed in contact with the peripheral part, the first main surface side and the second main surface side being recessed from the surface of the vibration part, respectively. Surrounding the periphery, formed thinner than the thickness of the periphery, the outer periphery is formed in a rectangular shape having a long side and a short side, from the surface of the periphery on the first main surface side and the second main surface side, respectively A concave portion formed by being recessed, and a frame portion that is in contact with the concave portion and surrounds the periphery of the concave portion, and is formed to be equal to or thicker than the thickness of the vibrating portion. Here, the concave portion is formed with a first through hole that penetrates only a region that is in contact with one short side and extends along the short side, and the extraction electrode drawn from the excitation electrode formed on the first main surface is the first through hole. It is drawn out from the first main surface of the frame portion to the second main surface of the frame portion through the 1 through hole.

  The piezoelectric vibrating piece according to the fourth aspect vibrates at a predetermined frequency, and is in contact with the vibrating unit, the vibrating unit having excitation electrodes formed on the first main surface and the second main surface opposite to the first main surface, respectively. And surrounding the vibration part, formed thinner than the thickness of the vibration part, and formed in contact with the peripheral part, the first main surface side and the second main surface side being recessed from the surface of the vibration part, respectively. Surrounding the periphery, formed thinner than the thickness of the periphery, the outer periphery is formed in a rectangular shape having a long side and a short side, from the surface of the periphery on the first main surface side and the second main surface side, respectively A concave portion formed by being recessed, and a frame portion that is in contact with the concave portion and surrounds the periphery of the concave portion, and is formed to be equal to or thicker than the thickness of the vibrating portion. Here, a second through hole is formed in the recess so as to penetrate only a region that is in contact with one long side and extends along the long side, and the extraction electrode drawn from the excitation electrode formed on the first main surface is the second. It is drawn out from the first main surface of the frame portion to the second main surface of the frame portion through the through hole.

  A piezoelectric device according to a fifth aspect includes a piezoelectric vibrating piece according to the first to fourth aspects, a lid plate bonded to the first main surface of the frame portion, and a base plate bonded to the second main surface of the frame portion. Have. The vibrating portion is sealed in a cavity surrounded by the frame portion, the base plate, and the lid plate.

  According to the piezoelectric vibrating piece and the piezoelectric device of the present invention, it is possible to prevent the crystal impedance (CI) value from being increased by forming a large area of the vibrating portion that vibrates at a predetermined frequency.

1 is an exploded perspective view of a piezoelectric device 100. FIG. It is AA sectional drawing of FIG. (A) is a top view of the piezoelectric vibrating piece 130. FIG. 4B is a bottom view of the piezoelectric vibrating piece 130. (A) is BB sectional drawing of Fig.3 (a) and FIG.3 (b). (B) is CC sectional drawing of Fig.3 (a) and FIG.3 (b). (C) is DD sectional drawing of Fig.3 (a) and FIG.3 (b). FIG. 4A is a top view of the piezoelectric vibrating piece 230. FIG. FIG. 6B is a bottom view of the piezoelectric vibrating piece 230. FIG. 6A is a top view of the piezoelectric vibrating piece 330. FIG. FIG. 6B is a bottom view of the piezoelectric vibrating piece 330. (C) is EE sectional drawing of Fig.6 (a) and FIG.6 (b).

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings. It should be noted that the scope of the present invention is not limited to these forms unless otherwise specified in the following description.

(First embodiment)
<Configuration of Piezoelectric Device 100>
FIG. 1 is an exploded perspective view of the piezoelectric device 100. The piezoelectric device 100 includes a lid plate 110, a base plate 120, and a piezoelectric vibrating piece 130. As the piezoelectric vibrating piece 130, for example, an AT-cut crystal vibrating piece is used. The AT-cut quartz crystal resonator element has a principal surface (YZ plane) inclined with respect to the Y axis of the crystal axis (XYZ) by 35 degrees 15 minutes from the Z axis in the Y axis direction around the X axis. In the following description, the new axes tilted with respect to the axial direction of the AT-cut quartz crystal vibrating piece are used as the Y ′ axis and the Z ′ axis. That is, in the piezoelectric device 100, the long side direction of the piezoelectric device 100 is described as the X-axis direction, the height direction of the piezoelectric device 100 is defined as the Y′-axis direction, and the direction perpendicular to the X and Y′-axis directions is described as the Z′-axis direction. .

  The piezoelectric vibrating piece 130 includes a vibrating part 131 that vibrates at a predetermined frequency and is formed in a rectangular shape, a peripheral part 132 that surrounds the vibrating part 131, a concave part 133 that surrounds the peripheral part 132, and a frame part 134 that surrounds the concave part 133. And a connecting portion 135 that is formed to the same thickness as the vibrating portion 131 and connects the vibrating portion 131 and the frame portion 134. In the following description, the main surface on the + Y′-axis side of the piezoelectric vibrating piece is referred to as a first main surface 139a, and the main surface on the −Y′-axis side is referred to as a second main surface 139b. Excitation electrodes 136 are formed on the first main surface 139a and the second main surface 139b of the vibration part 131, respectively. In addition, an extraction electrode 137 is extracted from each excitation electrode 136 to the frame portion 134 via the connecting portion 135.

  The base plate 120 includes a concave portion 121 recessed to the −Y′-axis side, a joint surface 122 surrounding the concave portion 121, a −Z′-axis side of the joint surface 122 on the + X-axis side, and −X And a connection electrode 123 disposed at a corner on the + Z ′ axis side on the axis side. The bonding surface 122 is bonded to the second main surface 139b of the frame portion 132 of the piezoelectric vibrating piece 130 via a bonding material 140 (see FIG. 2). A pair of mounting terminals 124 are formed on the surface of the base plate 120 on the −Y′-axis side. Further, base castellations 126 that are recessed inward of the base plate 120 are formed on the side surfaces of the four corners of the base plate 120. A castellation electrode 125 is formed on the side surface of the base castellation 126 on the −Z ′ axis side on the + X axis side and on the + Z ′ axis side on the −X axis side. The castellation electrode 125 electrically connects the connection electrode 123 and the mounting terminal 124.

  The lid plate 110 has a concave portion 111 that is recessed in the + Y′-axis direction and a joint surface 112 that surrounds the concave portion 111 on the surface at the −Y′-axis side. The bonding surface 112 is bonded to the first main surface 139a of the frame portion 132 of the piezoelectric vibrating piece 130 via a bonding material 140 (see FIG. 2).

  FIG. 2 is a cross-sectional view taken along the line AA of FIG. In the piezoelectric device 100, the bonding surface 112 of the lid plate 110 is bonded to the first main surface 139 a of the frame portion 134 of the piezoelectric vibrating piece 130 via the bonding material 140, and the second main surface of the frame portion 134 of the piezoelectric vibrating piece 130. The bonding surface 122 of the base plate 120 is bonded to the 139b via the bonding material 140. As a result, in the piezoelectric device 100, the cavity 101 is formed inside the piezoelectric device 100 by the concave portion 111 of the lid portion 110 and the concave portion 121 of the base portion 120. The cavity 101 is a sealed space, and the vibration part 131 is disposed in the cavity 101.

  An extraction electrode 137 drawn from the excitation electrode 136 formed on the first main surface 139 a of the vibration part 131 of the piezoelectric vibrating piece 130 is connected to the second main surface 139 b of the frame part 134 via the connection part 135 and the frame part castellation 138. Has been drawn to. In addition, the extraction electrode 137 drawn from the excitation electrode 136 formed on the second main surface 139 b of the vibration part 131 is drawn to the second main surface 139 b of the frame part 134. In this way, each extraction electrode 137 formed on the second main surface 139 b of the frame portion 134 is electrically connected to the connection electrode 123 formed on the base plate 120. As a result, the excitation electrode 136 is electrically connected to the mounting terminal 124.

  FIG. 3A is a top view of the piezoelectric vibrating piece 130. The planar shape of the vibrating portion 131 is formed in a rectangular shape having long sides extending in the X-axis direction and short sides extending in the Z′-axis direction. The peripheral portion 132 is in contact with the vibrating portion 131 and is formed so as to surround the vibrating portion 131. Further, the concave portion 133 is formed so as to contact the peripheral portion 132 and surround the peripheral portion 132, and the frame portion 134 is formed so as to contact the concave portion 133 and surround the concave portion 133. The outer shape of the peripheral portion 132 and the concave portion 133 is formed so that the long side extends in the X-axis direction and the short side extends in the Z′-axis direction. In addition, a connecting portion 135 is formed so as to connect the vibrating portion 131 and the frame portion 134. The connecting part 135 is connected to the center of the side on the −X axis side of the vibrating part 131, extends in the −X axis direction, and is connected to the frame part 134.

  The extraction electrode 137 extracted from the excitation electrode 136 formed on the first main surface 139a is extracted to the first main surface 139a of the frame portion 134 via the first main surface 139a of the connecting portion 135, and further on the −X axis side. Is pulled out to the second main surface 139b of the frame portion 134 through the side surface of the frame castellation 138 on the + Z ′ axis side.

  The recess 133 surrounds the peripheral portion 132 by a region extending in the X-axis direction and a region extending in the Z′-axis direction. Assuming that the width of the region extending in the X-axis direction of the recess 133 is L1, and the width of the region extending in the Z′-axis direction of the recess 133 is L2, in the piezoelectric vibrating piece 130, L1 and L2 are formed to have the same size.

  FIG. 3B is a bottom view of the piezoelectric vibrating piece 130. An extraction electrode 137 extracted from the excitation electrode 136 formed on the second main surface 139 b of the vibration part 131 is extracted from the excitation electrode 136 to the frame part 134 via the coupling part 135, and further the second main surface of the frame part 134. 139b is formed around the -Z'-axis side of the frame part 134 around the -Z'-axis side of the + X-axis side. In addition, the extraction electrode 137 drawn to the second main surface 139b of the frame portion 134 through the frame portion castellation 138 is at the corner of the second main surface 139b of the frame portion 134 on the + Z ′ axis side on the −X axis side. Is formed.

  FIG. 4A is a cross-sectional view taken along the line BB in FIGS. 3A and 3B. In FIG. 4A, the thickness of the vibrating portion 131 in the Y′-axis direction is H1, the thickness of the peripheral portion 132 in the Y′-axis direction is H2, the thickness of the concave portion 133 in the Y′-axis direction is H3, and the frame The thickness of the portion 134 in the Y′-axis direction is indicated as H4. Since the peripheral portion 132 is formed to be recessed from the first main surface 139a and the second main surface 139b of the vibration portion 131, H2 is smaller than H1. Since the recess 133 is formed to be recessed from the first main surface 139a and the second main surface 139b of the peripheral portion 132, H3 is smaller than H2. Since the frame portion 134 is formed so as to protrude from the first main surface 139a and the second main surface 139b of the recess 133, H4 is larger than H3. In the piezoelectric vibrating piece 130, the frame portion 134 is formed to have the same thickness as the vibrating portion 131, and H1 and H4 are formed to be equal. In the cross section in the short side direction of the piezoelectric vibrating piece 130, as shown in FIG. 4A, the vibrating part 131 is sandwiched between two steps of the peripheral part 132 and the recessed part 133. Thereby, in the piezoelectric vibrating piece 130, the vibration displacement is suppressed from leaking in the Z′-axis direction, and the leakage of vibration energy in the Z′-axis direction is suppressed.

  FIG. 4B is a cross-sectional view taken along the line CC in FIGS. 3A and 3B. In the cross section in the long side direction of the piezoelectric vibrating piece 130, as shown in FIG. 4B, the vibrating part 131 is sandwiched between two steps of the peripheral part 132 and the recessed part 133. Thereby, in the piezoelectric vibrating piece 130, the vibration displacement is suppressed from leaking in the X-axis direction, and the leakage of vibration energy in the X-axis direction is suppressed.

  FIG.4 (c) is DD sectional drawing of Fig.3 (a) and FIG.3 (b). In FIG. 4C, the extraction electrode 137 formed on the second main surface 139b not existing in the DD cross section is shown surrounded by a dotted line for the sake of explanation. In the piezoelectric vibrating piece 130, the connecting portion 135 is formed with the same thickness H <b> 1 as the vibrating portion 131. Further, the first main surfaces 139a of the vibrating portion 131, the connecting portion 135, and the frame portion 134 are formed on the same plane and are formed so as not to have a step. Similarly, the second main surfaces 139b of the vibrating portion 131, the connecting portion 135, and the frame portion 134 are also formed on the same plane with no step. Therefore, the extraction electrode 137 extending from the excitation electrode 136 to the frame portion 134 via the connecting portion 135 is formed on a flat surface having no step.

  In the piezoelectric vibrating piece 130, as shown in FIGS. 3A, 3 </ b> B, 4 </ b> A, and 4 </ b> B, the vibrating portion 131 is a portion other than the connecting portion 135 and a peripheral portion 132. And the two steps of the recess 133. As a result, leakage of vibration energy generated in the vibration part 131 from the vibration part 131 is prevented, so that the piezoelectric vibrating piece 130 can obtain stable vibration characteristics. Further, when the electrode is formed in a step, there is a concern that the electrode may be thin at the corner portion of the step and the wire may be disconnected, but the piezoelectric vibrating piece 130 is shown in FIG. In addition, the extraction electrode 137 is extracted from the vibrating portion 131 to the frame portion 134 through the connecting portion 135, so that the extraction electrode 137 is not formed in a step as much as possible. Thereby, disconnection of the extraction electrode 137 is prevented.

  Further, in the conventional piezoelectric vibrating piece, etching was performed for a long time in order to penetrate the recess 133 other than the connecting portion 135 in the Y′-axis direction. As the etching time becomes longer, the width of the recess 133 corresponding to L1 and L2 (see FIG. 3A) also increases. Since the dimension of the outer shape of the piezoelectric vibrating piece cannot be increased, the area of the vibrating portion 131 is relatively narrowed by the expansion of L1 and L2. When the area of the vibrating part 131 is reduced, the crystal impedance (CI) value is increased, and the vibration characteristics of the piezoelectric vibrating piece 130 may be deteriorated.

  Since the piezoelectric vibrating piece 130 is formed without penetrating the recess 133, the etching time can be shortened, and the widths of L1 and L2 can be made narrower than when penetrating the recess 133. Thereby, the area of the vibration part 131 can be increased, the crystal impedance (CI) value can be lowered, and the deterioration of the vibration characteristics of the piezoelectric vibrating piece 130 can be prevented.

(Second Embodiment)
In the piezoelectric vibrating piece, a through hole penetrating the piezoelectric vibrating piece may be formed in a part of the recess. A piezoelectric vibrating piece in which a through hole is formed in a part of the recess will be described below. In the following description, the same parts as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and the description thereof is omitted.

<Configuration of Piezoelectric Vibrating Piece 230>
FIG. 5A is a top view of the piezoelectric vibrating piece 230. The piezoelectric vibrating piece 230 includes a vibrating part 131, a peripheral part 132, a concave part 133, and a frame part 234. A castellation 138 (see FIG. 3A) is not formed in the frame portion 234, but the other configuration is the same as that of the frame portion 134. Further, the connecting portion 135 (see FIG. 3A) is not formed in the piezoelectric vibrating piece 230.

  A through hole 233 that penetrates the recess 133 in the Y′-axis direction is formed in a part of the recess 133 of the piezoelectric vibrating piece 230. The through-hole 233 extends in the −Z′-axis direction from the corner of the recess 133 on the −Z′-axis side on the −Z′-axis side and in contact with the −X-axis-side side of the recess 133. An extraction electrode 237 is extracted in the −X-axis direction from the excitation electrode 136 formed on the first main surface 139 a of the vibration part 131. The extraction electrode 237 is extracted to the first main surface 139a of the frame portion 234, and is further extracted to the second main surface 139b of the frame portion 234 through the through hole 233. Further, when the entire width in the Z′-axis direction of the recess 133 is L4, the width L3 of the through-hole 233 in the Z′-axis direction is shorter than L4.

  FIG. 5B is a bottom view of the piezoelectric vibrating piece 230. The extraction electrode 237 drawn from the first main surface 139a of the piezoelectric vibrating piece 230 to the second main surface 139b of the frame portion 234 through the through hole 233 is on the + Z′-axis side of the second main surface 139b of the frame portion 234. -Pulled out to the corner on the X-axis side. In addition, from the excitation electrode 136 formed on the second main surface 139b of the vibration part 131, the extraction electrode 237 extends to the frame part 234 in the + X-axis direction, and further extends in the −Z′-axis direction to the first of the frame part 234. The second main surface 139b is drawn out to the corner on the + Z-axis side on the + X-axis side.

  In the piezoelectric vibrating piece 230, as shown in FIGS. 5A and 5B, the periphery of the vibrating portion 131 is surrounded by a peripheral portion 132 and a concave portion 133. Therefore, the vibration energy of the vibration part 131 is difficult to leak out of the vibration part 131, and an increase in the crystal impedance (CI) value can be suppressed.

  In addition, the piezoelectric vibrating piece 230 is preferable because the concave portion 133 is formed so as to surround the peripheral portion 132, so that the extraction position is less limited when the extraction electrode 237 is extracted from the vibration portion 131 to the frame portion 234. For example, in the piezoelectric vibrating piece 230, as shown in FIG. 5B, the excitation electrode 136 formed on the surface at the −Y′-axis side of the vibrating portion 131 is not the −X-axis direction but the + X-axis direction. An extraction electrode 237 is extracted in the direction. Thereby, in the piezoelectric vibrating piece 230, the entire length of the extraction electrode 237 can be shortened, and the entire electrical resistance of the extraction electrode 237 can be suppressed low.

  Furthermore, the AT-cut quartz crystal vibrating piece performs thickness shear vibration in the X-axis direction. However, when the length of the vibration part 131 in the X-axis direction is short, excitation is performed in the X-axis direction in the vicinity of the thickness shear vibration in the X-axis direction. Spurious vibration that seems to be torsional vibration occurs, and frequency temperature characteristics such as frequency jump are adversely affected with small temperature changes. The influence of this spurious vibration can be reduced when the length of the vibration part 131 in the X-axis direction is increased. In the piezoelectric vibrating piece 230, when the concave portion 132 is formed on the + X axis side and the −X axis side of the vibrating portion 131, a through hole is formed on the entire + X axis side and the −X axis side of the vibrating portion 131. Compared to the above, the length of the vibrating portion 131 in the X-axis direction can be increased. Thereby, the influence of spurious vibration can be suppressed. Further, the length L3 of the through hole 233 is desirably set to a length such that the end of the through hole 233 on the −Z′-axis side does not overlap the excitation electrode 136 in the X-axis direction. This is because the through hole 233 has a larger width than the recess 133, and thus prevents the through hole 233 from affecting the excitation electrode 136 that causes the vibration of the vibration part 131.

<Configuration of Piezoelectric Vibration 330>
FIG. 6A is a top view of the piezoelectric vibrating piece 330. The piezoelectric vibrating piece 330 includes a vibrating part 131, a peripheral part 132, a concave part 133, and a frame part 234. In the piezoelectric vibrating piece 330, the connecting portion 135 (see FIG. 3A) is not formed. In addition, a through hole 333 that penetrates the recess 133 in the Y′-axis direction is formed in a part of the recess 133 of the piezoelectric vibrating piece 330. The through-hole 333 is formed to extend in the + X-axis direction from the + Z′-axis side end of the recess 133 on the −Z′-axis side in contact with the + Z′-axis side of the recess 133. The length L5 of the through-hole 333 in the X-axis direction is equal to or less than the entire length L6 of the recess 133 in the X-axis direction, and at least the extraction electrode 337 can be drawn out from the first main surface 139a to the second main surface 139b. Formed in size.

  From the excitation electrode 136 formed on the surface at the + Y′-axis side of the vibration part 131, the extraction electrode 337 is extracted toward the + Z′-axis side corner at the −X-axis side. Further, the extraction electrode 337 is extracted to the second main surface 139 b of the frame portion 234 through the through hole 333.

  FIG. 6B is a bottom view of the piezoelectric vibrating piece 330. The extraction electrode 337 drawn from the first main surface 139 a of the piezoelectric vibrating piece 330 to the second main surface 139 b of the frame portion 234 through the through hole 333 is on the + Z′-axis side of the second main surface 139 b of the frame portion 234. -Pulled out to the corner on the X-axis side. Further, from the excitation electrode 136 formed on the second main surface 139b of the vibration part 131, the extraction electrode 337 is linearly extended to the angle on the −Z ′ axis side on the + X axis side of the second main surface 139b of the frame part 234. It is pulled out in the shape.

  As shown in FIGS. 6A and 6B, the extraction electrode 337 can be extracted from the vibrating portion 131 to the frame portion 234 by the shortest distance by forming the recess 133. In addition, the width of the extraction electrode 337 can be adjusted. Therefore, the extraction electrode 337 can be formed by appropriately adjusting the electric resistance so as to be minimized.

  FIG.6 (c) is EE sectional drawing of Fig.6 (a) and FIG.6 (b). In FIG. 6C, the extraction electrode 337 extracted from the excitation electrode 136 formed on the surface at the + Y′-axis side of the vibration part 131 is connected to the first main surface 139 a via the inner peripheral side surface of the frame part 234. A state of being drawn out from the second main surface 139b is shown. Further, a state in which the extraction electrode 337 extracted from the excitation electrode 136 formed on the second main surface 139b is extracted to the frame portion 234 via the peripheral portion 132 and the recess 133 is shown.

  The vibrating portion 131 is surrounded by a peripheral portion 132 that is recessed from the surface of the vibrating portion 131, and the peripheral portion 132 is further surrounded by a recessed portion 133 or a through hole 333 that is recessed from the surface of the peripheral portion 132. As described above, in the piezoelectric vibrating piece 330, by forming two steps around the vibrating portion 131, vibration energy from the vibrating portion 131 can be reduced without forming a through-hole so as to surround the periphery of the peripheral portion 234. Leakage can be suppressed.

  In the piezoelectric vibrating piece 330, like the piezoelectric vibrating piece 230, the increase in the crystal impedance (CI) value is suppressed by completely surrounding the vibrating portion 131 with the peripheral portion 132, and the + X axis side of the vibrating portion 131 and Since no through-hole is formed on the entire X-axis side, the influence of spurious vibration is suppressed, and frequency jumps and the like with a small temperature change are prevented. Further, in the piezoelectric vibrating piece 330, the vibration part 131 mainly vibrates in the X-axis direction, and thus the influence on the width in the Z′-axis direction of the vibration part 131 is small. Therefore, even if the through hole 333 is formed on the + Z′-axis side of the vibrating part 131 and the size of the vibrating part 131 is reduced in the + Z′-axis direction, a frequency jump or the like with a small temperature change hardly occurs.

  As described above, the optimal embodiment of the present invention has been described in detail. However, as will be apparent to those skilled in the art, the present invention can be implemented with various modifications and variations within the technical scope thereof, Moreover, the features of each embodiment can be implemented in various combinations.

  For example, in FIG. 4C, the frame portion 134 is separated from the first main surface 139a and the second main surface 139b of the connecting portion 137 so that the thickness H4 of the frame portion 134 is thicker than the thickness H1 of the vibrating portion 131. You may form so that it may protrude. At this time, since the cavity can be formed in the piezoelectric device even if the recess 111 of the lid plate 110 and the recess 121 of the base plate 120 are not formed, it is not necessary to form the cavity in the lid plate and the base plate. At this time, the manufacturing process of the lid plate and the base plate can be simplified.

  In the above embodiment, the piezoelectric vibration element is an AT-cut crystal vibration element. However, the present invention can be applied to a BT cut that vibrates in the thickness-slip mode. The present invention can also be applied to a tuning fork type crystal vibrating element. Furthermore, the piezoelectric vibration element can be basically applied not only to a crystal material but also to a piezoelectric material including lithium tantalate, lithium niobate, or piezoelectric ceramic.

DESCRIPTION OF SYMBOLS 100 ... Piezoelectric device 101 ... Cavity 110 ... Lid board 111 ... Recessed part 112 ... Bonding surface 120 ... Base board 121 ... Recessed part 122 ... Bonding surface 123 ... Connection electrode 124 ... Mounting terminal 125 ... Castation electrode 126 ... Base castellation 130, 230 , 330 ... Piezoelectric vibrating piece 131 ... Vibrating part 132 ... Peripheral part 133 ... Recessed part 134, 234 ... Frame part 135 ... Connecting part 136 ... Excitation electrode 137, 237, 337 ... Extraction electrode 138 ... Frame part castellation 139a ... First main Surface 139b ... Second main surface 140 ... Bonding material 233, 333 ... Through hole H1 ... Thickness in Y'-axis direction of vibrating portion 131 H2 ... Thickness in peripheral portion 132 in Y'-axis direction H3 ... Y 'in recess 133 Thickness in the axial direction H4 ... Thickness in the Y′-axis direction of the frame portion 134 L1 ... Width of the region extending in the X-axis direction of the recess 133 L2 ... Width of the region extending in the Z'-axis direction of the recess 133 L3 ... Width in the Z'-axis direction of the through hole 233 L4 ... Z-axis direction of the entire recess 133 Width L5: Length of through-hole 333 in X-axis direction L6: Length of entire recess 133 in X-axis direction

Claims (5)

A vibrating portion that vibrates at a predetermined frequency and in which excitation electrodes are respectively formed on the first main surface and the second main surface opposite to the first main surface;
Surrounding the vibration part in contact with the vibration part, formed thinner than the thickness of the vibration part, and recessed from the surface of the vibration part on the first main surface side and the second main surface side, respectively. The surrounding area,
The peripheral portion is in contact with and surrounds the peripheral portion, and is formed thinner than the peripheral portion. The first main surface side and the second main surface side are respectively recessed from the surface of the peripheral portion. A recess,
A frame portion that is in contact with the concave portion and surrounds the concave portion, and is formed to be equal to or thicker than the thickness of the vibrating portion;
Formed in a part of the peripheral portion and the concave portion, extending from the vibrating portion to the frame portion, connecting the vibrating portion and the frame portion, and formed with the same thickness as the thickness of the vibrating portion, A first main surface side and a second main surface side, the surface of the vibration portion and a connecting portion having no step,
A piezoelectric vibrating piece in which an extraction electrode is drawn out from each excitation electrode to the frame portion via the connecting portion. A castellation that is recessed inside the frame portion is formed on a part of the outer side surface of the frame portion,
The extraction electrode drawn from the excitation electrode formed on the first main surface is drawn from the first main surface of the frame portion to the second main surface of the frame portion via the castellation. The piezoelectric vibrating piece according to the description. A vibrating portion that vibrates at a predetermined frequency and in which excitation electrodes are respectively formed on the first main surface and the second main surface opposite to the first main surface;
Surrounding the vibration part in contact with the vibration part, formed thinner than the thickness of the vibration part, and recessed from the surface of the vibration part on the first main surface side and the second main surface side, respectively. The surrounding area,
The peripheral portion is in contact with and surrounds the peripheral portion, is formed thinner than the peripheral portion, has an outer periphery formed in a rectangular shape having a long side and a short side, and the first main surface side and the second side A recess formed by recessing from the surface of the peripheral portion on the main surface side,
A frame part that is in contact with the concave part and surrounds the concave part, and is formed to be the same as or thicker than the thickness of the vibrating part,
The concave portion is formed with a first through-hole penetrating only a region in contact with one of the short sides and extending along the short side,
The extraction electrode extracted from the excitation electrode formed on the first main surface is piezoelectric vibration extracted from the first main surface of the frame portion to the second main surface of the frame portion through the first through hole. Piece. A vibrating portion that vibrates at a predetermined frequency and in which excitation electrodes are respectively formed on the first main surface and the second main surface opposite to the first main surface;
Surrounding the vibration part in contact with the vibration part, formed thinner than the thickness of the vibration part, and recessed from the surface of the vibration part on the first main surface side and the second main surface side, respectively. The surrounding area,
The peripheral portion is in contact with and surrounds the peripheral portion, is formed thinner than the peripheral portion, has an outer periphery formed in a rectangular shape having a long side and a short side, and the first main surface side and the second side A recess formed by recessing from the surface of the peripheral portion on the main surface side,
A frame part that is in contact with the concave part and surrounds the concave part, and is formed to be the same as or thicker than the thickness of the vibrating part,
A second through-hole penetrating only a region extending along the long side in contact with one of the long sides is formed in the recess,
The extraction electrode extracted from the excitation electrode formed on the first main surface is piezoelectric vibration extracted from the first main surface of the frame portion to the second main surface of the frame portion through the second through hole. Piece. The piezoelectric vibrating piece according to any one of claims 1 to 4,
A lid plate joined to the first main surface of the frame portion;
A base plate joined to the second main surface of the frame portion,
The vibration unit is a piezoelectric device sealed in a cavity surrounded by the frame unit, the base plate, and the lid plate.

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