JP2004222006A - Holding structure of piezoelectric vibration element in piezoelectric device, piezoelectric vibrator, piezoelectric oscillator, insulating package, and piezoelectric vibration element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase stress relaxing capability by an adhesive material and to prevent the fluctuation of a holding state by the adhesive material even when stress in the direction of rotating a piezoelectric vibration element or in the other directions is generated at a holding part by the adhesive material by an impact or the like due to falling and a collision, etc., in a piezoelectric device structured such that the piezoelectric vibration element is supported in cantilever by a conductive adhesive material on an internal terminal inside a package. <P>SOLUTION: The piezoelectric device comprises an insulating package 2 provided with a recessed part 3 having the internal terminal 4 and provided with a mounting terminal 6 conducted with the internal terminal on an outer bottom surface, and the piezoelectric vibration element 10 provided with the constitution that an excitation electrode 12 and a lead electrode 13 are formed on a piezoelectric substrate 11 and supported in cantilever inside the recessed part by electrically and mechanically connecting the lead electrode onto the internal terminal by the conductive adhesive material 5. The internal terminal is constituted such that the tip side thickness of the conductive adhesive material is thicker than the thickness of the middle part or/and the rear part in connecting the lead electrode of the piezoelectric vibration element through the conductive adhesive material. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an improvement in a support structure of a piezoelectric vibrating element that is cantilevered by an electrically conductive adhesive on internal terminals arranged in a surface mounting package.
[0002]
[Prior art]
A piezoelectric vibrator such as a surface-mount type crystal vibrator has a configuration as shown in a vertical cross-sectional view of FIGS. 8A and 8B and a package plan view. That is, in the piezoelectric vibrator, the piezoelectric vibrating element 110 is separated from the internal terminal (electrode pad) 103 disposed on the inner bottom surface of the recess 102 of the package 101 made of an insulating material such as ceramic by using the conductive adhesive 104. It has a configuration in which it is supported in a holding state and the opening of the recess 102 is hermetically sealed with a metal lid 115. On the outer bottom surface of the package, mounting terminals 105 electrically connected to the internal terminals 103 are arranged. The piezoelectric vibrating element 110 includes an excitation electrode 112 on each of the front and back surfaces of a piezoelectric substrate 111 such as a quartz substrate, and a lead electrode 113 extending from each excitation electrode 112 to an edge of the substrate.
FIG. 8C is an enlarged view showing a connection structure using a conductive adhesive. In the adhesive holding portion shown here, since the upper surface of the internal terminal 103 is flat, the upper surface of the internal terminal 103 is connected to the lead electrode 113. Is hardened with a uniform thickness on the upper surface of the internal terminal 103.
By the way, the piezoelectric vibrator obtains an output by utilizing the mechanical vibration of the piezoelectric substrate 111 constituting the piezoelectric vibrating element 110. For this reason, if a portion of the piezoelectric substrate 111 related to mechanical vibration is held by the conductive adhesive 104, the vibration may be damped and the characteristics may be degraded. Therefore, in order to ensure a wide vibration area, a small piezoelectric vibrator generally adopts a cantilever holding structure in which holding portions made of a conductive adhesive are collected on one edge side of a substrate as shown in FIG. With such a cantilever holding structure, the mechanical restraining end is deviated in one direction of the substrate, so that the vibration does not attenuate at the free end (toward the substrate tip). As a result, characteristic deterioration due to holding is suppressed.
However, in such a cantilever structure, since the holding end exists only on one side of the substrate, a moment is generated by the weight of the piezoelectric vibrating element due to mechanical external force due to impact, vibration, or the like due to dropping, collision, or the like.
[0003]
FIGS. 9A and 9B are image diagrams in which a moment is generated in the piezoelectric vibrating element due to an impact at the time of dropping or the like. As described above, the moment generated in the piezoelectric vibrating element 110 around the holding end of the conductive adhesive 104 causes elastic deformation of the adhesive, and stress concentration occurs in the adhesive. At this time, if energy absorption due to elastic deformation of the adhesive is not sufficient, minute peeling or stress relaxation occurs at the bonding portion between the piezoelectric vibration element and the adhesive due to stress concentration on the adhesive side. As a result, the holding state of the end portion of the piezoelectric vibrating element by the adhesive changes, and characteristic deterioration (frequency fluctuation, change in equivalent resistance value) occurs.
The thickness of the conductive adhesive 104 sandwiched between the upper surface of the internal terminal 103 and the piezoelectric vibration element 110 (lead electrode 113) is usually about 20 μm, and the viscosity of the adhesive and the pressing pressure of the piezoelectric vibration element However, it is difficult to control the viscosity of the adhesive uniformly because the conditions vary depending on the amount of solvent and the temperature. For this reason, there is also a problem that the thickness of the adhesive located between the internal terminal and the piezoelectric vibrating element varies depending on the production lot.
Although the following patent documents describe the structure of the electrode pads in the package of the piezoelectric vibrator, there is no solution to the above-mentioned conventional problems.
[Patent Document 1] Japanese Patent Application Laid-Open No. Hei 7-240563 [Patent Document 2] Japanese Patent Application Laid-Open No. 8-130432 [Patent Document 3] Japanese Patent Application Laid-Open No. 10-22776 [Patent Document 4] Japanese Patent Application Laid-Open No. 10-135762 [Patent Document 5] [Patent Document 6] Japanese Patent Application Laid-Open No. 2000-31773
[Patent Document 7] JP-A-2000-138532
[Patent Document 8] JP-A-2001-77656
[Patent Document 9] JP-A-2001-102891
[Patent Document 10] JP-A-2001-285011
[Patent Document 11] JP-A-2001-345664
[Patent Document 12] JP-A-2002-26679
[Patent Document 13] JP-A-2002-84160
[Patent Document 14] JP-A-2002-76812
[Patent Document 15] JP-A-2002-100950
[Patent Document 16] JP-A-2002-111426
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above, and in a piezoelectric device having a structure in which a piezoelectric vibrating element is cantilevered on an internal terminal in a package by a conductive adhesive, the piezoelectric vibrating element is formed by an adhesive due to an impact due to drop, collision, or the like. In the piezoelectric device that enables the holding part to rotate the piezoelectric vibrating element, even if stress is generated in other directions, the stress relaxation ability by the adhesive is enhanced to prevent the holding state from changing due to the adhesive. An object of the present invention is to provide a structure for holding a piezoelectric vibration element.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has the following configuration.
First, according to the first aspect of the present invention, an insulating package having a recess provided with an internal terminal and having a mounting terminal electrically connected to the internal terminal on an outer bottom surface, and an excitation electrode and a lead electrode formed on a piezoelectric substrate are formed. A piezoelectric vibrating element that is cantilevered in the recess by electrically and mechanically connecting the lead electrode to the internal terminal with a conductive adhesive on the internal terminal, and hermetically seals the opening of the recess The internal terminal, when the lead electrode of the piezoelectric vibration element is connected via the conductive adhesive, the thickness of the conductive adhesive on the tip side is reduced. It is characterized in that it is configured to be thicker than the thickness of the middle part and / or the rear part.
By increasing the thickness of the bonded part in the direction of the tip of the base plate (in the direction of the free end), the moment generated in the cantilever structure due to the stress absorption due to the elastic deformation in the adhesive part and the stylus touched by it It becomes possible to absorb. That is, in the piezoelectric vibrator having the cantilever structure, elastic energy absorption at the bonding portion due to external force such as a drop impact increases. As a result, even after being subjected to a drop impact, minute adhesive peeling and stress relaxation do not occur at the bonding portion of the piezoelectric substrate holding portion, and frequency fluctuation hardly occurs.
The thickness of the conductive adhesive in the present invention (common to all claims) is the thickness of the portion sandwiched between the inner bottom surface of the recess (the upper surface of the internal terminal) and the lower surface of the piezoelectric vibrating element (the lower surface of the lead electrode). And does not include the portion protruding behind the rear edge of the piezoelectric substrate.
According to a second aspect of the present invention, in the first aspect, the internal terminal is provided with a convex portion in a middle portion or a rear portion of the upper surface.
Since the internal terminal portion on which the piezoelectric substrate base plate is mounted has a projection structure, the adhesive thickness can be controlled to be constant regardless of the adhesive viscosity. The position of the convex portion may be any position as long as a thick portion can be formed on the entire adhesive.
The projections may be formed by thickening a part of the conductive film constituting the internal terminal, or forming a part of the upper surface of the insulating package in a projecting shape and forming the conductive film thereon. The internal terminals and the projections may be formed at once. This is common to the following claims.
According to a third aspect of the present invention, in the first or second aspect, the internal terminal is provided with a downwardly inclined surface or a downwardly curved surface at least at a front end thereof. Since the thickness of the front end wall of the internal terminal gradually decreases downward, the thickness of the adhesive applied thereon gradually increases toward the front, so that the holding strength can be increased.
[0006]
According to a fourth aspect of the present invention, in the first aspect, the front-rear dimension of the internal terminal is shorter than the front-rear dimension of the applied conductive adhesive, and the inner wall of the recess beyond the front edge of the internal terminal and the piezoelectric substrate. And a portion of the conductive adhesive protrudes between them.
The purpose of providing the thick portion in front of the conductive adhesive is to improve the holding strength (stress absorption relaxation), so that the adhesive does not need to be located on the internal terminals, and the thick portion is concave. It may protrude into the insulating material portion of the inner wall, or protrude into the piezoelectric substrate portion on the lower surface of the piezoelectric vibrating element.
According to a fifth aspect of the present invention, there is provided an insulating package having a recess provided with an internal terminal and having a mounting terminal electrically connected to the internal terminal on an outer bottom surface, and an excitation electrode and a lead electrode formed on a piezoelectric substrate. And a piezoelectric vibrating element that is cantilevered in the recess by electrically and mechanically connecting the lead electrode on the internal terminal by a conductive adhesive, and a metal that hermetically seals the opening of the recess. A lid, at least when the piezoelectric vibrating element is connected to the internal terminal via the conductive adhesive, the thickness of the conductive adhesive at the tip side is an intermediate portion, or And / or is configured to be thicker than the thickness of the rear part.
Instead of increasing the thickness of the front part of the conductive adhesive by applying the shape processing to the package side, the lower surface on the side of the piezoelectric vibrating element is processed, so it is processed all at once when etching the piezoelectric substrate And manufacturing becomes easy. Then, it becomes possible to improve the drop impact characteristics and control the thickness of the adhesive.
According to a sixth aspect of the present invention, in the fifth aspect, the piezoelectric substrate constituting the piezoelectric vibrating element has a convex portion on a part of a lower surface facing the internal terminal. Since the protrusion structure is provided on the piezoelectric substrate, the drop impact characteristics can be improved and the thickness of the adhesive can be controlled without providing the protrusion structure on the package.
A piezoelectric vibrator according to a seventh aspect of the present invention includes the piezoelectric vibrating element holding structure according to any one of the first to sixth aspects.
The surface mount type piezoelectric vibrator has a configuration in which a piezoelectric vibrating element is cantilevered in an insulating package. By adopting the holding structure described in each claim to this piezoelectric vibrator, it is possible to obtain the function and effect described in each claim.
An eighth aspect of the present invention provides a piezoelectric oscillator including the piezoelectric vibrator according to the seventh aspect and an oscillation circuit.
By combining the piezoelectric vibrator described in claim 7 with, for example, an oscillation circuit component formed as an IC component to form a unit, a piezoelectric oscillator exhibiting the above-described effects can be constructed.
According to a ninth aspect of the present invention, there is provided an insulating package having the structure according to the first to fourth aspects.
According to a tenth aspect of the present invention, there is provided a piezoelectric vibration element including the structure according to the fifth or sixth aspect.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
FIGS. 1A, 1B, 1C, and 1D are longitudinal sectional views showing a structure of a quartz oscillator as an example of a piezoelectric device according to an embodiment of the present invention, and a plan view with a metal lid removed. FIG. 3 is a plan view of a package and an enlarged view of a main part.
In this crystal resonator 1, a piezoelectric vibrating element 10 is cantilevered by using a conductive adhesive 5 on internal terminals (electrode pads) 4 arranged on the inner bottom surface of a recess 3 of a package 2 made of an insulating material such as ceramic. It is supported in a state, and the opening of the recess 3 is hermetically sealed with a metal lid 15. On the outer bottom surface of the package, mounting terminals 6 electrically connected to the internal terminals 4 are arranged. Further, the crystal resonator element 10 has a configuration in which excitation electrodes 12 are formed on both front and back surfaces of a crystal substrate 11, and lead electrodes 13 extending from each excitation electrode 12 to the edge of the substrate.
[0008]
The characteristic configuration of the embodiment of FIG. 1 is in the shape of the internal terminal 4, and when the lead electrode 13 of the piezoelectric vibration element 10 is connected via the conductive adhesive 5, the upper surface of the internal terminal 4 and the lead electrode 13 is characterized in that the thickness t1 of the front end side of the conductive adhesive 5 sandwiched between the conductive adhesive 13 and the conductive adhesive 5 is larger than the thickness t2 of the intermediate portion.
That is, in this embodiment, the internal terminal 4 has a thick portion by forming the convex portion 20 at the intermediate portion on the upper surface thereof. For this reason, the thickness of the conductive adhesive 5 sandwiched between the upper surface of the internal terminal 4 and the lead electrode 13 is t1 on the front side (the tip side of the quartz crystal vibrating element) with respect to the projection 20 and the projection The thickness of the conductive adhesive located between the flat upper surface 20 and the lead electrode 13 is t2, and the relationship is t1> t2. Accordingly, the thickness t2 of the conductive adhesive on the convex portion 20 is equal to the thickness of the adhesive (typically, 20 μm) between the internal terminal and the lower surface of the crystal vibrating element in the conventional piezoelectric vibrator shown in FIG. When the thickness is set to, the thickness of the adhesive at the front portion of the adhesive having the thickness t1 is increased by the thickness of the projection 20 as compared with the conventional adhesive thickness.
In this example, when the width A in the front-rear direction of the internal terminal 4 is 0.6 mm and the thickness B is 20 μm, the width C in the front-rear direction of the projection 20 is 0.2 mm, and the height D is 20 μm ( However, this is only an example). Therefore, the thickness t1 is 40 μm, and the thickness t2 is 20 μm.
Further, since the thickness t1 of the adhesive located forward of the convex portion 20 is defined by the height of the convex portion 20, the thickness t1 of the adhesive located forward is increased without being affected by the viscosity of the adhesive. It is possible to do.
As the method of forming the convex portion 20, in addition to the method of forming the convex portion 20 made of a conductive material on the internal terminal 4, it corresponds to the internal terminal 4 of the upper surface of the insulating material (ceramic) constituting the package 2. The internal terminal 4 and the projection 20 can be formed collectively by making the portion partially project and covering the region including the projecting portion with the conductor film constituting the internal terminal 4. This is a matter common to all the following embodiments.
As the conductive adhesive 5, for example, a silicon-based conductive adhesive is used, and the curing condition is heating at 180 ° C. for 2 hours.
As described above, in the present embodiment, the convex portion 20 is provided in the middle portion of the upper surface of the internal terminal 4. Therefore, when the upper surface of the internal terminal 4 is connected to the lower surface of the crystal resonator by the conductive adhesive, the convex portion 20 is formed. Assume that the thickness and amount of the adhesive located in front of 20 increase, and a moment is generated in the vertical direction (thickness direction) with respect to the quartz crystal vibrating element by the impact centering on the holding portion made of the adhesive. However, the stress can be sufficiently absorbed and relaxed. Therefore, stress due to elastic deformation of the adhesive does not remain, and deformation of the holding portion of the crystal unit due to the adhesive does not occur. That is, due to the concentration of stress on the adhesive side, minute peeling or stress relaxation does not occur at the bonding portion between the piezoelectric vibration element and the adhesive, and the holding state of the piezoelectric vibration element end by the adhesive changes. Thus, there is no possibility that characteristic deterioration (frequency fluctuation, change in equivalent resistance value) occurs.
[0009]
Next, FIG. 2 is a cross-sectional view of a main part showing a configuration of an internal terminal in a piezoelectric device according to a second embodiment of the present invention. In this embodiment, a shape is provided in which the protrusion 20 provided on the upper surface of the internal terminal 4 is moved rearward from the intermediate position in FIG.
Also according to this structure, the thickness t1 of the conductive adhesive located in front of the projection 20 is significantly larger than the thickness t2 of the adhesive on the projection 20, and the amount of the adhesive in that portion is reduced. Can increase. For this reason, according to the same principle as in the embodiment of FIG. 1, it is possible to absorb and reduce the damage caused by the moment due to an impact or the like, and to prevent deterioration of the characteristics.
Next, FIG. 3 is an explanatory diagram of a main part configuration of a piezoelectric device according to a third embodiment of the present invention. In the internal terminal 4 according to this embodiment, the thickness at both ends in the front-rear direction is downward. The configuration is characterized by being curved or linearly inclined so as to gradually decrease. In order to make the thickness t1 of the front part of the conductive adhesive 5 sandwiched between the internal terminal 4 and the crystal resonator 10 larger than the thickness t2 of the rear part, the front end of the internal terminal 4 is required. It is sufficient that only the portion 35 has a curved or inclined surface.
Also according to this structure, the thickness t1 of the conductive adhesive located above the curved or inclined front end 35 is greater than the thickness t2 of the adhesive located above the flat central portion of the internal terminal 4. And the amount of adhesive in that portion can be increased. For this reason, according to the same principle as in the embodiment of FIG. 1, it is possible to absorb and reduce the damage caused by the moment due to an impact or the like, and to prevent deterioration of the characteristics.
Next, FIG. 4 is an explanatory view of a main part configuration of a piezoelectric device according to a fourth embodiment of the present invention. The internal terminal 4 according to this embodiment has a conductive width in which the width of the internal terminal 4 in the front-rear direction is applied. By making the width of the adhesive 5 smaller than the width in the same direction, a part of the adhesive is protruded forward from the front end of the internal terminal 4. The thickness t1 of the conductive adhesive 5 located in front of the front end of the internal terminal 4 is increased by an amount corresponding to the thickness of the internal terminal 4, and the amount is also increased.
Also according to this structure, the thickness t1 of the conductive adhesive 5 located between the inner bottom surface of the recess located in front of the internal terminal 4 and the lower surface of the crystal element is reduced by the adhesive located above the upper surface of the internal terminal 4. Is significantly thicker than the thickness t2, and the amount of adhesive in that portion can be increased. For this reason, according to the same principle as in the embodiment of FIG. 1, it is possible to absorb and reduce the damage caused by the moment due to an impact or the like, and to prevent deterioration of the characteristics.
[0010]
Next, in the embodiment shown in FIGS. 5 and 6, the convex portion is formed at an appropriate position on the lower surface on the side of the crystal vibrating element, so that the conductive layer sandwiched between the inner bottom surface of the concave portion and the lower surface of the crystal vibrating element. It is characteristic that the amount of the front part of the adhesive is increased. That is, when the piezoelectric vibrating element 1 according to the embodiment of FIGS. 5 and 6 is connected to the internal terminal 4 via the conductive adhesive 5, the thickness of the conductive adhesive at the tip side is an intermediate part thereof. And / or is configured to be thicker than the thickness of the rear part.
First, in the embodiment of FIG. 5, the convex portion 40 is protruded at an appropriate position on the lower surface slightly displaced forward from the rear end of the crystal substrate 11 constituting the crystal resonator element 1. The position of the protrusion 40 is set so as to be included in the front-rear width of the internal terminal 4, and an electrode film constituting the lead electrode 13 is formed on at least a part of the protrusion 40. .
The protrusion 40 is formed by etching or machining.
In this embodiment, a convex portion 40 is formed at an appropriate position on the lower surface of the quartz substrate 11 facing the internal terminal 4. For this reason, the thickness of the conductive adhesive 5 sandwiched between the upper surface of the internal terminal 4 and the lower surface of the crystal substrate 11 (lead electrode 13) is more forward than the convex portion 40 (the tip side of the crystal vibrating element). ), T1 is reached, and the thickness of the conductive adhesive located between the flat lower surface of the projection 40 and the lead electrode 13 is t2, which is in a relationship of t1> t2. Therefore, when the thickness t2 of the conductive adhesive located immediately below the convex portion 40 is set to be equal to the thickness of the adhesive between the internal terminal and the lower surface of the crystal vibrating element in the conventional piezoelectric vibrator shown in FIG. In the front part of the adhesive having the thickness t1, the adhesive thickness is increased by the thickness of the projection 40 as compared with the conventional adhesive thickness.
In this example, for example, it is assumed that the quartz substrate 10 has a length in the front-rear direction of 2.8 mm, a thickness of 0.128 μm, and a center frequency of 13 MHz. The thickness of the projection 40 is 20 μm.
Further, since the thickness t1 of the adhesive positioned forward of the convex portion 40 is defined by the height of the convex portion 40, the thickness t1 of the adhesive positioned forward is increased without being affected by the viscosity of the adhesive. It is possible to do.
The protrusions 40 may be locally and independently formed only on the lower surface of the quartz substrate on which the lead electrodes 13 are provided, or may be formed by forming one long protrusion 40 over the entire length of the inner bottom surface of the recess. It may be arranged so as to straddle one lead electrode 13.
As described above, in the present embodiment, since the convex portion 40 is provided at a position corresponding to the lead electrode 13 of the crystal vibrating element 10, the upper surface of the internal terminal 4 and the lower surface of the crystal vibrating element (lead electrode) are electrically conductive adhesive. 5, the thickness and the amount of the adhesive located in front of the convex portion 40 are increased, and the shock is applied to the quartz vibrating element in the vertical direction (thickness) with respect to the holding portion made of the adhesive. ), The stress can be sufficiently absorbed and alleviated. Therefore, stress due to elastic deformation of the adhesive does not remain, and deformation of the holding portion of the crystal unit due to the adhesive does not occur. That is, due to the concentration of stress on the adhesive side, minute peeling or stress relaxation does not occur at the bonding portion between the piezoelectric vibration element and the adhesive, and the holding state of the piezoelectric vibration element end by the adhesive changes. Thus, there is no possibility that characteristic deterioration (frequency fluctuation, change in equivalent resistance value) occurs.
[0011]
FIG. 6 is a configuration diagram of a main part of a piezoelectric device according to a sixth embodiment of the present invention, and shows an example in which the protrusions 40 in FIG. 5 are arranged at positions along the rear edge of the quartz substrate 11. Configurations and effects other than the position of the protrusion 40 are the same as those of the embodiment of FIG.
Next, FIGS. 7A and 7B show frequency fluctuations after the drop impact test of the crystal resonator having the conventional structure and the crystal resonator according to each embodiment of the present invention. The condition of the drop impact is a result obtained by dropping on a concrete surface with a load of 200 g with one cycle (one time) in six directions of crystal axes X, Y and Z. As shown in FIG. 7B, in the crystal resonator according to the present embodiment, the frequency fluctuation due to the drop is small, and it is clear that the buffer effect by the thick portion in front of the conductive adhesive is enhanced. It is.
The present invention can be applied not only to a piezoelectric oscillator such as a quartz oscillator but also to a piezoelectric oscillator such as a quartz oscillator in which a quartz oscillator and an oscillation circuit are combined.
[0012]
【The invention's effect】
As described above, according to the present invention, in a piezoelectric device having a structure in which a piezoelectric vibrating element is cantilevered on an internal terminal in a package by a conductive adhesive, the piezoelectric vibrating element is dropped onto a holding portion of the adhesive by an impact due to collision or the like. Even if a stress is generated in the direction in which the piezoelectric vibrating element is rotated or in any other direction, the ability of the adhesive to alleviate the stress is enhanced to prevent the holding state from being changed by the adhesive.
[Brief description of the drawings]
FIGS. 1A, 1B, 1C and 1D are longitudinal sectional views showing a structure of a quartz oscillator as an example of a piezoelectric device according to an embodiment of the present invention, with a metal cover removed. The top view, the top view of a package, and the principal part enlarged view.
FIG. 2 is an essential part cross-sectional view showing a configuration of an internal terminal in a piezoelectric device according to a second embodiment of the present invention.
FIG. 3 is an explanatory diagram of a main configuration of a piezoelectric device according to a third embodiment of the present invention.
FIG. 4 is an explanatory diagram of a main part configuration of a piezoelectric device according to a fourth embodiment of the present invention.
FIG. 5
FIG. 13 is an explanatory diagram of a main part configuration of a piezoelectric device according to a fifth embodiment of the present invention.
FIG. 6 is an explanatory diagram of a main part configuration of a piezoelectric device according to a sixth embodiment of the present invention.
FIGS. 7A and 7B are diagrams showing comparative examples of frequency fluctuation after a drop impact test.
8 (a), (b) and (c) are explanatory views of a conventional example.
FIGS. 9A and 9B are views for explaining the drawbacks of the conventional example.
[Explanation of symbols]
1 crystal oscillator, 2 insulating package, 3 recess, 4 internal terminal (electrode pad), 5 conductive adhesive, 6 mounting terminal, 10 crystal oscillator (piezoelectric oscillator), 11 crystal substrate (piezoelectric substrate), 12 Excitation electrode, 13 Lead electrode, 15 Lid, 30 Convex part 35 Front end, 40 Convex part.

Claims (10)

An insulating package having a recess provided with an internal terminal and having a mounting terminal electrically connected to the internal terminal on the outer bottom surface; and a structure in which an excitation electrode and a lead electrode are formed on a piezoelectric substrate; A piezoelectric vibrating element that is cantilevered in the recess by electrically and mechanically connecting the lead electrode with a conductive adhesive, and a metal lid that hermetically seals the opening of the recess. In piezoelectric devices,
When the internal terminal is connected to the lead electrode of the piezoelectric vibration element via the conductive adhesive, the tip side thickness of the conductive adhesive is larger than the thickness of the middle part and / or the rear part. A structure for holding a piezoelectric vibrating element in a piezoelectric device, wherein the piezoelectric vibrating element is configured to be thicker. The holding structure for a piezoelectric vibrating element in a piezoelectric device according to claim 1, wherein the internal terminal has a convex portion at a middle portion or a rear portion of an upper surface thereof. The structure for holding a piezoelectric vibration element in a piezoelectric device according to claim 1, wherein the internal terminal has a downward inclined surface or a downward curved surface at least at a front end thereof. The longitudinal dimension of the internal terminal is shorter than the longitudinal dimension of the applied conductive adhesive, and a portion of the conductive adhesive is located between the inner wall of the recess beyond the front edge of the internal terminal and the piezoelectric substrate. The structure for holding a piezoelectric vibration element in a piezoelectric device according to claim 1, wherein the piezoelectric vibrating element is extended. An insulating package having a recess provided with an internal terminal and having a mounting terminal electrically connected to the internal terminal on the outer bottom surface; and a structure in which an excitation electrode and a lead electrode are formed on a piezoelectric substrate; A piezoelectric vibrating element that is cantilevered in the recess by electrically and mechanically connecting the lead electrode with a conductive adhesive, and a metal lid that hermetically seals the opening of the recess. In piezoelectric devices,
When the piezoelectric vibration element is connected to the internal terminal via the conductive adhesive, the thickness of the conductive adhesive on the tip side becomes larger than the thickness of the middle part and / or the rear part. A structure for holding a piezoelectric vibrating element in a piezoelectric device characterized by having the following configuration. The holding structure for a piezoelectric vibration element in a piezoelectric device according to claim 5, wherein the piezoelectric substrate constituting the piezoelectric vibration element has a projection on a part of a lower surface facing the internal terminal. A piezoelectric vibrator comprising the piezoelectric vibrator holding structure according to claim 1. A piezoelectric oscillator comprising the piezoelectric vibrator according to claim 7 and an oscillation circuit. An insulating package comprising the structure according to claim 1. A piezoelectric vibrating element comprising the structure according to claim 5.

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