JP2010021613A - Piezoelectric vibration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric vibration device that can cope with downsizing and has excellent impact resistance and good characteristics.
Both ends of a crystal piece 2 which is chamfered so as to gradually become thinner as approaching the end are both supported and joined to a recess 5 of a base 1, and the recess 5 is hermetically sealed with a flat lid. In the crystal resonator, the two end portions located on the diagonal line of the crystal piece 2 having a rectangular shape in plan view are bonded so as to correspond to the pair of mounting pads 12 and 12 formed obliquely opposite to the inner bottom surface 8 of the recess 5. Each is joined via a material 4. On the inner bottom surface 8, a pair of pillow parts 7, 7 are slightly separated from the free ends 24, 24 on the long side of the crystal piece toward the fixed ends 25, 25 on the long side, and the long side of the crystal piece Each is formed at a position close to the edge.
[Selection] Figure 1

Description

  The present invention relates to a piezoelectric vibration device used for electronic equipment and the like.

  With the recent reduction in size and height of piezoelectric vibration devices, crystal resonators are also becoming smaller. Further, further miniaturization is required for a package (hereinafter referred to as a base) used for a crystal resonator and a crystal vibrating piece (hereinafter referred to as a crystal piece) mounted inside the package. Since the thickness of an AT-cut crystal piece mainly used as a crystal piece is inversely proportional to the frequency, the thickness of an AT-cut crystal piece in a low frequency band is larger than that of a crystal piece in a high-frequency band. Therefore, for the purpose of obtaining good vibration characteristics, chamfering (hereinafter referred to as beveling) is performed on the end face of the flat crystal piece. Specifically, the bevel processing attenuates vibration energy at the support portion of the crystal piece (the end portion of the crystal piece) by thinning the end portion of the crystal piece, and at the center area of the front and back surfaces of the crystal piece. This is mechanical processing that obtains good vibration characteristics by confining vibration energy under the excitation electrode to be formed. For example, Patent Document 1 discloses a crystal resonator in which one end side of a crystal piece having such a shape is cantilevered and bonded inside the base.

  As miniaturization progresses in low-frequency band AT-cut crystal pieces, the difference in thickness between the thick part at the center and the thin part at the end is large. The cross-sectional shape approaches. When one end of a crystal piece having such a shape is cantilevered and supported via a conductive bonding material on a mounting pad formed inside the base, the free end of the crystal piece when subjected to an external impact or the like There is a risk that the side portion is bent and the central portion, which is a thick portion, comes into contact with the bottom surface of the base. On the other hand, as shown in FIG. 7, in the case of the configuration in which both ends of the long side of the crystal vibrating piece are held (so-called both-end support), the risk can be reduced as compared with the cantilever support configuration. (For example, see Patent Document 2 for a dual-support type)

JP 2003-8387 JP 2005-198237 A

  By the way, the bevel processing is performed on both sides of the long side and the short side of the crystal piece having a rectangular shape in plan view. That is, also in the short side direction, the vicinity of the center is the thickest, and both end portions are the thinnest. When both ends of the crystal piece having such a shape are supported and bonded on the mounting pad formed inside the base, the substantially central portion of the two short side ends facing each other through the bonding material, respectively. Be joined.

  However, the substantially central portion of the end portion of the short side described above is the thickest portion, and the vibration energy in the short side direction is a relatively high region. By fixing such a part, the vibration characteristic of the quartz crystal piece is hindered, causing deterioration of the characteristic. Further, in the support form (two-point bonding) at the substantially central portion of the two short side ends facing each other, the bending of the crystal piece can be sufficiently absorbed when subjected to an external impact. In some cases, the crystal piece comes into contact with the bottom surface of the base. As a result, defects such as damage to the excitation electrodes formed on the front and back main surfaces of the crystal piece and oscillation stoppage may occur.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a piezoelectric vibration device that can cope with downsizing and has excellent impact resistance and good characteristics.

  In order to achieve the above object, according to the first aspect of the present invention, a piezoelectric vibrating piece having a rectangular shape in plan view with at least a chamfered end is both supported in a recess formed in a base having a rectangular shape in plan view. A piezoelectric vibration device that is supported and bonded and the recess is hermetically sealed with a flat lid, and two end portions located on the diagonal line of the piezoelectric vibrating piece having a rectangular shape in plan view are formed on the inner bottom surface of the recess. Corresponding to a pair of mounting pads formed obliquely, each of them is bonded via a bonding material, and is an inner bottom surface of the recess, from the pair of mounting pads to the long side direction of the piezoelectric vibrating piece A pair of pillows made of an insulating material are formed at positions that are spaced apart from each other by a certain distance, close to the edge of the long side, and not including the corners that are free ends of the piezoelectric vibrating piece. . With such a configuration, it is possible to prevent contact between the piezoelectric vibrating piece and the inner bottom surface of the base when an external impact is applied.

  According to the above configuration, by placing the pillow portion facing the position, for example, a large external impact is applied to the piezoelectric vibration device, and the free end side of the piezoelectric vibration piece is greatly bent, and the piezoelectric vibration piece (side facing the bottom surface of the base) Can be prevented from coming into contact with the inner bottom surface of the base. Specifically, when the piezoelectric vibration device receives the external impact, the surface facing the inner bottom surface of the base of the piezoelectric vibrating piece and the pillow portion are the thickest part of the piezoelectric vibrating piece (the long side of the piezoelectric vibrating piece In the direction, the contact is made before the inner bottom surface of the base and the inner bottom surface of the base.

  Corners of the plate-like piezoelectric vibrating piece are likely to be chipped or chipped due to external impact or the like, and when such chipping or chipping occurs, various characteristics of the piezoelectric vibrating device are adversely affected. According to the configuration of the present invention, the pair of pillow portions is the inner bottom surface of the base, and is spaced apart from the pair of mounting pads by a predetermined distance in the long side direction of the piezoelectric vibrating piece. Since it is formed at a position that is close and does not include a corner that becomes the free end of the piezoelectric vibrating piece, the free end of the two long sides of the piezoelectric vibrating piece (specifically, the corner on the side that becomes the free end) No tangible object is formed immediately below. That is, the corners of the piezoelectric vibrating piece do not come into contact with the pillow portion when receiving an external impact, and the corners and chipping of the piezoelectric vibrating piece can be prevented. Thereby, characteristic deterioration of the piezoelectric vibrating device can be suppressed.

  Further, according to the configuration of the present invention, the two end portions positioned on the diagonal line of the piezoelectric vibrating piece having a rectangular shape in plan view correspond to the pair of mounting pads formed obliquely opposed to the inner bottom surface of the base via the bonding material. Since each of the configurations is bonded, it is possible to suppress deterioration of the characteristics of the piezoelectric vibrating device as compared to a configuration in which the substantially central portion of the short side end portion of the piezoelectric vibrating piece having the same shape is bonded. In other words, according to the support structure of the present invention, the region (region including the corner) where the vibration energy is attenuated in the short side direction of the piezoelectric vibrating piece is bonded to the mounting pad. Good characteristics can be obtained.

  Further, according to the above configuration, since the pillow portion is formed of an insulating material, for example, when the excitation electrode for driving the piezoelectric vibrating piece is formed largely to the vicinity of the periphery of the front and back surfaces of the piezoelectric vibrating piece, Even if the contact state between the excitation electrode and the pillow portion changes due to an impact, the charge does not move and the capacitance between the excitation electrodes does not change, so that the oscillation frequency can be prevented from changing. Therefore, a piezoelectric vibration device having excellent impact resistance can be obtained.

  According to a second aspect of the present invention, the pair of pillow portions may be formed diagonally opposite at a position close to a corner portion that is a free end of the two long sides of the piezoelectric vibrating piece.

  According to the above configuration, by placing the pillow portion facing the position, for example, a large external impact is applied to the piezoelectric vibration device, and the free end side of the piezoelectric vibration piece is greatly bent, and the piezoelectric vibration piece (side facing the bottom surface of the base) Can be prevented from coming into contact with the inner bottom surface of the base. Specifically, when the piezoelectric vibration device receives the external impact, the surface facing the inner bottom surface of the base of the piezoelectric vibrating piece and the pillow portion formed at the position are the thickest part (piezoelectric). The contact between the piezoelectric vibrating piece and the inner bottom surface of the base can be avoided because the contact is made prior to the bottom surface of the base.

  According to the invention of claim 3, the pair of pillow portions may be formed at a position close to a substantially central portion of the two long sides of the piezoelectric vibrating piece.

  When chamfering a rectangular piezoelectric vibrating piece is performed until the cross-sectional shape of the piezoelectric vibrating piece becomes a biconvex lens shape (biconvex shape), the long side and the short side are processed at the same time. Near the center of the side is the thickest. Even when the piezoelectric vibrating piece having such a shape is mounted on the base, according to the above configuration, the pair of pillow portions is formed at a position close to a substantially central portion of the two long sides of the piezoelectric vibrating piece. Therefore, the positional relationship between the top portion of the curved surface and the pillow portion in the long side direction of the piezoelectric vibrating piece is located substantially on the same line. Therefore, it is effective in suppressing the displacement amount in the long side direction of the piezoelectric vibrating piece when subjected to an external impact. Even when the piezoelectric vibrating piece is bent by an external impact, the end (edge) on the short side of the piezoelectric vibrating piece comes into contact with the pillow portion, so that the displacement is also made in the short side direction. The amount can be suppressed, and the impact resistance performance is improved. The chamfering process is not limited to both surfaces (front and back) of the piezoelectric vibrating piece, and can be applied even if only one surface is chamfered. That is, the above configuration is also effective for a piezoelectric vibrating piece that is mounted with the surface on which the convex curved surface is formed facing the inner bottom surface of the base.

  As described above, according to the present invention, it is possible to provide a piezoelectric vibration device that can cope with downsizing and has excellent impact resistance and good characteristics.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In the embodiment of the present invention, an example in which a surface-mounted crystal resonator is applied to a piezoelectric device will be described. The crystal resonator applied in the present embodiment includes a base that is concave in cross section, a crystal resonator element that is rectangular in plan view, and a flat lid.

-First embodiment-
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a plan view of a crystal resonator showing a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is taken along line BB in FIG. FIG. In FIG. 1 to FIG. 3, for convenience of explanation, description of a lid (to be described later) for hermetically sealing the opening of the base is omitted. Also, in FIG. 2 to FIG. 3, description of external connection terminals formed on the bottom surface (back surface) of the base and connection means for electrically connecting the external connection terminals and the mounting pads inside the base is omitted. . Furthermore, in FIG. 2 thru | or FIG. 3, description of the various electrodes (after-mentioned) formed in the front and back of a quartz-crystal vibrating piece is abbreviate | omitted.

  FIG. 1 is a plan view of a crystal resonator showing a first embodiment of the present invention, in which a description of a flat lid that hermetically seals a recess 5 is omitted, and a crystal resonator element is provided inside a base 1. 2 (hereinafter abbreviated as “crystal piece 2”) is bonded via the conductive bonding material 4. In the present embodiment, the external dimensions of the crystal resonator are long side × short side = 3.2 mm × 2.5 mm, and the height is about 0.75 mm. The external dimensions of the crystal unit are examples, and are not limited to the external dimensions.

  As shown in FIGS. 1 and 2, the base 1 is a box-like body having a concave portion 5 and having a rectangular shape in plan view with an upper portion opened. The base 1 is a laminate of three ceramic green sheets, in which a frame-like second layer 1b is laminated on a flat plate-like first layer 1a serving as a bottom plate, and a frame-like second layer is formed on the second layer. The third layer 1c is laminated. These three layers are positioned and laminated after printing the internal wiring conductors at predetermined positions, and are integrally formed by firing. The upper surface of the third layer 1c is flat.

  Around the recess 5 of the base 1, a bank portion 10 composed of the second layer 1b and the third layer 1c is formed in an annular shape, and the inner bottom surface 8 of the recess 5 (on the upper surface of the first layer 1a, In a region where the bank portion 10 is not formed), a pair of stepped portions 11 and 11 are formed. The pair of step portions 11, 11 are formed in a positional relationship diagonally opposite the diagonal line of the inner bottom surface 8 that is substantially rectangular in plan view. A pair of mounting pads 12 and 12 made of a metal film are formed on the upper surfaces of the pair of steps 11 and 11. The mounting pad 12 has a layer structure in which tungsten metallization is applied to the upper surface of the stepped portion 11, nickel plating is applied to the upper portion thereof, and gold plating is further applied to the upper portion thereof. The mounting pad 12 is electrically connected to an external connection terminal (not shown) formed on the bottom surface (back surface) of the base 1 via a wiring conductor (not shown) formed inside the base. Yes. The electrical connection between the mounting pad 12 and the external connection terminal may be performed by forming a conductor (so-called castellation) in the vertical direction of the corner portion of the outer periphery of the base.

  A rectangular parallelepiped pillow portion 7 made of the same material as the base 1 is formed on the inner bottom surface 8 of the base 1. The pillow portion 7 is formed in a pair, and the formation position thereof is the inner bottom surface 8 of the recess 5, and is separated from the pair of mounting pads 12, 12 by a certain distance in the long side direction of the crystal piece 2. The position is close to the long edge of the piece. Specifically, as shown in FIG. 1, the pillow portions 7 and 7 are formed at positions slightly separated from the free ends 24 and 24 on the long side of the crystal piece in the direction of the fixed ends 25 and 25 on the long side. Has been. And it arrange | positions so that the long side edge part of a crystal piece may overlap with the upper surface of the pillow part 7 which is substantially rectangular in planar view by planar view. The pair of pillow portions 7 and 7 are in a positional relationship that does not overlap with the excitation electrodes formed on the front and back surfaces of the crystal piece 2 in plan view. In this embodiment, the external dimension of the pillow part in plan view is 0.2 mm × 0.15 mm, but the external dimension of the pillow part is not limited to the external dimension. Further, the pillow portion and the excitation electrode formed on the front and back surfaces of the crystal may partially overlap in plan view.

  The pair of step portions 11 and 11 and the pair of pillow portions 7 and 7 are formed in the same layer and have substantially the same thickness (height). However, since the metal film (mounting pads 12 and 12) composed of the three layers described above is formed on the upper surfaces of the pair of step portions 11 and 11, the step portion 11 side is higher than the pillow portion 7 when the base is completed. (Thick). In the present embodiment, the height of the mounting pad 12 from the inner bottom surface 8 is about 110 μm, and the height of the pillow portion 7 from the inner bottom surface 8 is about 100 μm. Due to such a height relationship, the pillow portion 7 is not in contact with the crystal piece 2 in a steady state (a state where the crystal piece 2 is bonded to the mounting pad 12 using a conductive bonding material). Thereby, in a steady state, since vibration at the free end of the quartz crystal piece is not hindered, good vibration characteristics can be obtained. Furthermore, since the pillow portions are arranged in a pair and obliquely opposite each other in the vicinity of the free end of the crystal piece, the external shock applied to the crystal piece is larger than when only one pillow portion is formed on the inner bottom surface 8. Can be received in a well-balanced manner, and deterioration of vibration characteristics can be suppressed.

  As shown in FIG. 1, the crystal piece 2 used in the present embodiment is an AT-cut crystal diaphragm having a rectangular shape in plan view, and beveled. By the bevel processing, the cross-sectional shape is close to a biconvex lens that gradually becomes thinner as it approaches the end (see FIG. 2). Moreover, as shown in FIG. 3, the short side direction of the crystal piece 2 is also a cross-sectional shape close to a biconvex lens. The oscillation frequency of the crystal unit in this embodiment is 9.8 MHz. In this embodiment, a crystal piece processed into a cross-sectional shape close to a biconvex lens is taken as an example, but a biconvex lens shape (biconvex shape), or only one side of the crystal piece is a convex lens shape (planoconvex shape) The present invention is also applicable to a shape in which only the end portion is chamfered and the main surface (flat portion) of the crystal piece remains, and the chamfered portion is formed with a plurality of curvatures. is there. That is, the present invention can be applied to a crystal piece having a curvature on at least the surface facing the inner bottom surface of the base.

  On the front and back surfaces of the crystal piece 2, excitation electrodes 21a and 21b for driving the crystal piece 2 (21b on the back side is not shown), extraction electrodes 22a and 22b drawn from the excitation electrode, and the extraction A pair of connection electrodes 23 a and 23 b formed at both ends of the crystal piece 2 are formed in connection with the electrodes. Each of the connection electrodes 23a and 23b is formed so as to cover the short side and the long side near the corner including the corner of the crystal piece. The extraction electrode and the connection electrode are formed so as to be positioned on a diagonal line of the crystal piece in plan view. These electrodes are formed on the quartz piece by vapor deposition or the like in the order of chromium (Cr) -gold (Au) -chromium (Cr). In addition, the film | membrane structure of the said electrode is not limited to this, For example, on the crystal piece, in the order of Cr-Au, on the crystal piece, in the order of Cr-Ag (silver), or on the crystal piece Further, the film may be formed in the order of Cr—Ag—Cr.

  The connection electrodes 23 a and 23 b formed on the front and back surfaces of the crystal piece 2 are bonded to the pair of mounting pads 12 and 12 on a one-to-one basis via the conductive bonding material 4. The joining is performed by curing the conductive joining material 4 in an atmosphere controlled to a predetermined temperature profile. As the conductive bonding material, for example, a silicone-based conductive resin bonding material is used. The conductive bonding material is not limited to the silicone-based conductive resin bonding material, and an epoxy-based conductive resin bonding material may be used in addition to the silicone-based bonding material. Here, in the state where the bonding between the crystal piece 2 and the mounting pad 12 is completed (steady state), as shown in FIG. 2, there is a gap between the pillow portion 7 and the surface 26 facing the inner bottom surface 8 of the crystal piece 2. A slight gap is formed.

  By disposing the pillow portion 7 in such a position, for example, a large external impact is applied to the crystal resonator, the two free ends 24 and 24 side of the crystal piece are greatly bent, and the surface facing the inner bottom surface 8 of the crystal piece 2 26 (hereinafter abbreviated as “opposing surface”) can be prevented from coming into contact with the inner bottom surface 8 of the base. Specifically, when the crystal unit receives the external impact, the surface 26 facing the inner bottom surface 8 of the crystal piece 2 and the pillow portion 7 formed at the position are the thickest part of the crystal piece 2. Since the contact is made prior to the inner bottom surface 8 (substantially central portion in the long side direction of the crystal piece), contact between the crystal piece 2 and the inner bottom surface 8 can be avoided.

  Further, as shown in FIG. 3, since the pillow portion 7 is formed in a position close to the peripheral edge of the short side of the crystal piece 2 in the short side direction of the crystal piece 2, for example, a large external impact is applied to the crystal unit. Even if the free ends 24, 24 side of the crystal piece is bent, the pillow portion 7 comes into contact with the crystal located immediately above the pillow portion, so that the amount of displacement of the free ends 24, 24 is suppressed, and the crystal piece 2 and the inner bottom surface 8 Can be prevented. That is, when the crystal resonator receives the external impact, the crystal piece 2 comes into contact with the pillow portion 7 so that the gap between the facing surface 26 and the inner bottom surface 8 can be maintained.

  The lid used in the present embodiment is made of a ceramic material having a rectangular shape in plan view, and a sealing material is formed on the entire lower surface of the lid, that is, on the joint surface side with the upper surface of the bank portion 10 of the base 1. Has been. In the present embodiment, low melting point glass is used as the sealing material. The lid material may have a layer structure in which Kovar is used as a base material in addition to a ceramic material, and a nickel plating layer and a gold plating layer are formed thereon. In this case, a metal brazing material such as an An—Sn alloy is used as the sealing material. After the crystal piece 2 and the mounting pad 12 are bonded via the conductive bonding material 4, the frequency is finely adjusted so that the outer periphery of the lid body substantially matches the upper surface of the bank portion 10 of the base 1. By covering the lid and heating to a predetermined temperature, the glass material formed on the lid is melted, and the lid and the base 1 are hermetically sealed. By this hermetic sealing, a surface-mount type crystal unit is completed.

  Corners of the plate-like piezoelectric vibrating piece are likely to be chipped or chipped due to external impact or the like, and when such chipping or chipping occurs, various characteristics of the piezoelectric vibrating device are adversely affected. According to the configuration of the present invention, the pair of pillow portions is the inner bottom surface of the base, and is spaced apart from the pair of mounting pads by a predetermined distance in the long side direction of the piezoelectric vibrating piece. Since it is formed at a position that is close and does not include a corner that becomes the free end of the piezoelectric vibrating piece, the free end of the two long sides of the piezoelectric vibrating piece (specifically, the corner on the side that becomes the free end) No tangible object is formed immediately below. That is, the corners of the piezoelectric vibrating piece do not come into contact with the pillow portion when receiving an external impact, and the corners and chipping of the piezoelectric vibrating piece can be prevented. Thereby, characteristic deterioration of the piezoelectric vibrating device can be suppressed.

  Further, according to the configuration of the present invention, the two end portions positioned on the diagonal line of the piezoelectric vibrating piece having a rectangular shape in plan view correspond to the pair of mounting pads formed obliquely opposed to the inner bottom surface of the base via the bonding material. Since each of the configurations is bonded, deterioration in characteristics of the piezoelectric vibrating device can be suppressed as compared with a configuration in which the substantially central portion of the short side end portion of the piezoelectric vibrating piece having the same shape is bonded. In other words, according to the support structure of the present invention, the region (region including the corner) where the vibration energy is attenuated in the short side direction of the piezoelectric vibrating piece is bonded to the mounting pad. Good characteristics can be obtained.

  Further, according to the above configuration, since the pillow portion is formed of an insulating material, for example, when the excitation electrode for driving the piezoelectric vibrating piece is formed largely to the vicinity of the periphery of the front and back surfaces of the piezoelectric vibrating piece, Even if the contact state between the excitation electrode and the pillow portion changes due to an impact, the charge does not move and the capacitance between the excitation electrodes does not change, so that the oscillation frequency can be prevented from changing. Therefore, a piezoelectric vibration device having excellent impact resistance can be obtained.

-Second Embodiment-
A second embodiment of the present invention will be described with reference to FIG. 4 is a plan view of a crystal resonator showing a second embodiment of the present invention, FIG. 5 is a cross-sectional view taken along the line CC in FIG. 4, and FIG. 6 is taken along the line DD in FIG. FIG. 5 to 6, various electrodes formed on the front and back surfaces of the crystal piece, external connection terminals formed on the bottom surface of the base, and internal wiring conductors formed inside the base are omitted. In addition, about the same component as 1st Embodiment, while attaching | subjecting the same number and omitting a part of description, it has an effect similar to 1st Embodiment. Hereinafter, a description will be given focusing on differences from the first embodiment.

  As shown in FIGS. 4 to 5, the pillow part is different from the first embodiment in the formation position of the pillow part 7. Specifically, the pillow portion 7 is formed at a substantially central portion of the two long sides of the crystal piece 2 so as to face a position close to the edge of the two long sides. By providing the pillow portion at such a position, for example, when a large external impact is applied to the crystal resonator, the central portion in the long side direction which is the thickest portion of the chamfered crystal piece 2 and the base Contact with the bottom surface can be suppressed.

  In the present embodiment, the pillow portion is formed lower (thin) than the height (thickness) of the step portion 11. In this case, the pillow portion 7 is formed by laminating and applying an insulating material (for example, resin) and then curing.

  Since the pair of pillow portions is formed at a position close to the substantially central portion of the two long sides of the crystal piece 2, the positional relationship between the top of the curved surface in the long side direction of the crystal piece 2 and the pillow portion is approximately. It will be located on the same line. Therefore, it is effective in suppressing the displacement amount in the long side direction in the short side direction of the crystal piece 2 when receiving an external impact. That is, even when the crystal piece 2 is bent due to an external impact, the short-side end (edge) of the crystal piece 2 is in contact with the pillow portion. Can be suppressed, and impact resistance performance is improved.

  In the embodiment of the present invention, a glass material is taken as an example of a sealing material, but laser sealing, electronic using a ceramic base and a metal lid, and using a brazing material such as a silver brazing material as the sealing material. It can also be applied to sealing by beam sealing. Furthermore, in the embodiment of the present invention, a surface-mount type crystal resonator is taken as an example, but the present invention can also be applied to other surface-mount type piezoelectric vibration devices used for electronic devices such as a crystal filter and a crystal oscillator.

  The present invention can be implemented in various other forms without departing from the spirit or main features thereof. Therefore, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  It can be applied to mass production of piezoelectric vibration devices.

1 is a plan view of a crystal resonator showing a first embodiment of the present invention. Sectional drawing along the AA line of FIG. Sectional drawing along the BB line of FIG. The top view of the crystal oscillator which shows the 2nd Embodiment of this invention. Sectional drawing along CC line of FIG. Sectional drawing along the DD line | wire of FIG. Sectional drawing of the long side direction which shows the example of the conventional crystal oscillator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 1a 1st layer 1b 2nd layer 1c 3rd layer 2 Crystal vibrating piece 21 Free end 22 Fixed end 3 Cover body 4 Conductive joining material 5 Recess 7 Pillow 8 Inner bottom 10 Dyke 11 Step 12 12 Mounting pad 21a , 21b Excitation electrode 22a, 22b Extraction electrode 23a, 23b Connection electrode 24 Free end 25 Fixed end 26 Opposing surface

Claims (3)

A piezoelectric vibrating piece having a rectangular shape in plan view with at least a chamfered end is supported and joined in a recess formed in a base having a rectangular shape in plan view, and the concave portion is hermetically sealed with a flat lid. A piezoelectric vibration device,
The two end portions located on the diagonal line of the piezoelectric vibrating piece having a rectangular shape in plan view are bonded to each other via a bonding material so as to correspond to a pair of mounting pads formed obliquely opposed to the inner bottom surface of the recess. Become
An inner bottom surface of the recess, each being spaced apart from the pair of mounting pads by a predetermined distance in the long side direction of the piezoelectric vibrating piece, close to the edge of the long side, and free end of the piezoelectric vibrating piece A piezoelectric vibration device characterized in that a pair of pillow portions made of an insulating material are formed at positions not including the corner portions.   2. The piezoelectric vibration device according to claim 1, wherein the pair of pillow parts are formed obliquely opposed to each other at a position close to a corner part that is a free end of two long sides of the piezoelectric vibration piece. .   2. The piezoelectric vibration device according to claim 1, wherein the pair of pillow portions are respectively formed at positions close to a substantially central portion of two long sides of the piezoelectric vibration piece.

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