JPH1065478A - Support structure for piezoelectric vibration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the support structure for the piezoelectric vibrator device in which alignment of a conductive adhesives is easy, flowing out of the conductive adhesives to the outside of the support is prevented and the adhesive strength (close adhesion) of the conductive adhesives is improved. SOLUTION: In the structure of the piezoelectric vibration device which is provided with at least a base 2 to which lead terminals 2, 2, 23 are implanted with isolation, supports 24, 26 fitted to the lead terminals 22, 23, a piezoelectric diaphragm 10 on which an exciting electrode is formed to a front side and a rear side, a conductive adhesives S adhering the supports 24, 26 and the piezoelectric diaphragm 10 electrically and mechanically, and a cap 3 sealing the piezoelectric diaphragm 10 air-tightly and where the piezoelectric diaphragm 10 is mounted perpendicularly to a plane of the supports 24, 26, a rough face 24a is formed to a part of the supports 24, 26 to which the conductive adhesives is coated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric vibrating device using a piezoelectric vibrating plate such as a quartz plate, and more particularly to a support structure for a piezoelectric vibrating device.

[0002]

2. Description of the Related Art Piezoelectric vibrating devices such as monolithic quartz filters are used as frequency selecting means in, for example, small-sized handheld communication devices. As a conventional example, a general configuration of a monolithic crystal filter will be described with reference to FIG. FIG. 7 is a front view of the monolithic crystal filter. Note that the base portion partially shows the internal structure.

An input electrode 91 and an output electrode 92 are formed in parallel on the front surface of a quartz plate 90, and these input and output electrodes 92 are formed on the back surface.
Common electrodes (not shown) corresponding to the output electrodes are also formed in parallel. The quartz plate 90 is supported upright by support members 84, 85, 86 formed on the base 8 via a conductive bonding material S. The base 8 is made of a metallic shell 80.
And lead terminals 81 and 83 implanted and fixed through an insulator 80a such as glass, and an earth terminal 82 directly fixed to the shell. The input / output electrodes 91 and 92 are connected to input / output terminals 81 and 83, respectively.
4 are connected in common to a ground terminal 82. And it is hermetically sealed by the cap 3.

[0004]

However, the conventional support structure of the piezoelectric vibration device has a problem that the application position and the application amount of the conductive bonding material of the support tend to vary. Further, there is a problem that the conductive bonding material flows out from a desired application position on the support.

[0005] In particular, a support for a piezoelectric vibrating device in which the piezoelectric vibrating plate is mounted perpendicularly to a support plane (upright support) is formed in the direction of gravity. The conductive bonding material often flowed downward from the position. As a result, the application amount of the conductive bonding material varies, and as a result, the CI value (crystal impedance) with respect to the initial setting as the piezoelectric device and the frequency temperature characteristic change, and the input / output support support and In the support for grounding, the conductive bonding material leaks downward from a desired application position, thereby causing poor conduction and poor bonding. Further, a support for a piezoelectric vibration device in which the piezoelectric vibration plate is mounted perpendicularly to a support plane (upright support) has a problem that the contact area with the piezoelectric vibration plate is small and the bonding strength is low. Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the positioning of the conductive bonding material is easy, the conductive bonding material is prevented from flowing out of the support, and the conductive bonding material is formed. It is an object of the present invention to provide a support structure for a piezoelectric vibration device with improved bonding strength (adhesion).

[0007]

In order to solve the above-mentioned problems, a support structure for a piezoelectric vibration device according to the present invention comprises: a base having at least two lead terminals implanted insulated from each other; A support body attached to the terminal, a piezoelectric diaphragm having excitation electrodes formed on the front and back surfaces,
A conductive bonding material for electromechanically bonding the support body and the piezoelectric vibration plate, and at least a cap for hermetically sealing the piezoelectric vibration plate, wherein the piezoelectric vibration plate is disposed on a plane of the support body. In the support structure of a vertically mounted piezoelectric vibrating device, a conductive bonding material reservoir is formed at least in a portion of the support body where the conductive bonding material is applied.

[0008] According to the above configuration, it is possible to eliminate the variation by setting the application position and the application amount of the conductive bonding material in the pool. Then, the pool prevents the conductive bonding material from flowing out of the support. The bonding strength (adhesion) of the conductive bonding material is improved by the anchor effect of the pool.

A base on which at least two lead terminals are implanted insulated from each other; a support body attached to each of the lead terminals; a piezoelectric diaphragm having excitation electrodes formed on the front and back surfaces; A conductive bonding material for electromechanically bonding the support body and the piezoelectric vibration plate, and at least a cap for hermetically sealing the piezoelectric vibration plate, wherein the piezoelectric vibration plate is disposed on a plane of the support body. In the support structure of a vertically mounted piezoelectric vibration device, a rough surface is formed on at least a portion of the support body to which the conductive bonding material is applied.

[0010] According to the above configuration, the application position and the application amount of the conductive bonding material can be set to the rough surface portion to eliminate the variation. Then, the rough surface portion prevents the conductive bonding material from flowing out of the support. The bonding strength (adhesion) of the conductive bonding material is improved by the anchor effect due to the rough surface portion.

A base having at least two lead terminals implanted insulated from each other, a support body attached to each of the lead terminals, a piezoelectric vibrating plate having excitation electrodes formed on the front and back surfaces, A conductive bonding material for electromechanically bonding the support body and the piezoelectric vibration plate, and at least a cap for hermetically sealing the piezoelectric vibration plate, wherein the piezoelectric vibration plate is disposed on a plane of the support body. In the support structure of a vertically mounted piezoelectric vibration device, at least one concave portion is formed in at least a portion of the support body where the conductive bonding material is applied.

According to the above configuration, the application position and the application amount of the conductive bonding material can be set in the concave portion to eliminate variations. Then, the concave portion prevents the conductive bonding material from flowing out of the support. The bonding strength (adhesion) of the conductive bonding material is improved by the anchor effect of the concave portion.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. FIG. 1A is a front view showing the inside of a cap and a part of a base of a crystal unit, and FIG. 1B is a side view of FIG. 1A. FIG. 2 is a side view of a support body showing a modification of the first embodiment of the present invention.

The piezoelectric vibrating plate 10 is an AT-cut quartz plate, and is processed into a circular shape as a whole. Excitation electrodes 11 are provided on the front and back surfaces (the back surface is not shown), and the extraction electrodes 11a, 1a are connected from the respective electrodes to the end surfaces of the piezoelectric vibrating plate.
2a is pulled out. The base supporting the piezoelectric vibration plate 10 includes the base body 2 and a support body. The base body 2 has a configuration in which lead terminals 22 and 23 are implanted in a metal shell 20 insulated through glass 20a, and a slit 24a is provided above the lead terminals 22 and 23.
(The other is not shown) and plate-like supports 24 and 26 on which a rough surface portion 24b (the other is not shown) serving as a conductive bonding material storage portion are formed by means such as spot welding. ing. The slit 2
4a is formed by press working, for example, and the rough surface portion 2
4b can be formed by, for example, polishing. The extraction electrodes 11a and 12a of the piezoelectric vibrating plate are supported by supports 24 and 26 and are conductively bonded by a conductive bonding material S. Then, the piezoelectric vibrating plate 10, the support members 24, 2
6 and the like are covered with a cap 3 and hermetically sealed.

In the first embodiment of the present invention, the slit 24
The rough surface portion 24b provided on the entire peripheral portion of a prevents the conductive bonding material from flowing out of the rough surface portion 24 of the support body. In particular, the conductive bonding material no longer flows downward (in the direction of gravity) due to gravity. Then, the position of the conductive bonding material is determined, the dispersion can be stably eliminated, and the bonding strength (adhesion) due to the anchor effect is improved.

In the first embodiment of the present invention, a rough surface is formed on the entire circumference of the slit, but FIGS.
As shown in (1), a rough surface may be formed at least on a portion to which the conductive bonding material is applied. Further, in FIG. 2E, the application position and the application amount of the conductive bonding material can be clearly indicated by being applied on one rough surface using the rough surfaces formed as a plurality as marks. It is configured as follows. In the first embodiment of the present invention, the rough surface portion is formed by polishing, but may be formed by etching or pressing. Further, in the first embodiment of the present invention, the rough surface portion is formed as the conductive bonding material reservoir, but may be formed by a concave portion, or the rough surface portion and the concave portion may be combined.

A second embodiment of the present invention will be described by taking a monolithic crystal filter as an example with reference to FIGS. FIG. 3A is a front view showing the inside of the cap and a part of the base of the monolithic crystal filter.
FIG. 3B is a cross-sectional view taken along line XX of FIG.
FIG. 3C is a partially enlarged cross-sectional view of the center support body of FIG. FIG. 4 is a side view of a center support body showing a modification of the second embodiment of the present invention. Note that the same parts as those in the conventional example are denoted by the same reference numerals.

The piezoelectric vibrating plate 90 is an AT-cut quartz plate, is processed into a circular shape as a whole, and the upper end is flattened. On the surface, input electrodes 91 and output electrodes 92 are provided in parallel and closely spaced at a predetermined interval, and lead electrodes 91a and 92a are drawn from the respective electrodes to the end face of the piezoelectric vibrating plate. On the back surface, the input electrode and the output electrodes 91 and 9 are provided.
2, two common electrodes (not shown) are provided,
An extraction electrode 9 is provided from each electrode to the lower end face of the piezoelectric vibrating plate.
3a is pulled out. These common electrodes are externally connected in common. The base supporting this piezoelectric diaphragm is
It comprises a base body 8 and a support body. Base body 8
The lead terminals 81 and 83 are insulated and implanted in a metal shell 80 via a glass 80a.
2 is directly connected to the shell, and lead terminals 8
Plate-like supports 84 and 86 having slits (not shown) formed thereon are mounted on the upper portions of the first and the first 83 by means such as spot welding. Further, the center support body 85 is spot-welded to the center portion of the upper surface of the base body in an upright state. A slit 85a is formed in an upper portion of the center support body 85, and a plurality of recesses 85b as a conductive bonding material pool are formed around the slit 85a. The slit 85a can be formed by, for example, etching, and the concave portion 85b can be formed by, for example, half etching. The extraction electrodes 91a and 92a of the piezoelectric vibrating plate are supported by supports 84 and 86, and are electrically conductively bonded by a conductive bonding material S. In addition, the lead electrode 93a on the common electrode side and the upper part of the center support body 85 are conductively joined, and the lead terminal 8 finally serving as a ground terminal is formed.
Conduction with 2. Then, the piezoelectric vibrating plate 90, the support members 84 and 86, the center support member 85 and the like are covered with the cap 3, and hermetically sealed.

In the second embodiment of the present invention, the slit 85
The plurality of recesses 85b provided around a prevent the conductive bonding material from flowing out of the recesses 85b of the center support body. In particular, the conductive bonding material no longer flows downward (in the direction of gravity) due to gravity. Then, the position of the conductive bonding material is determined, the dispersion can be stably eliminated, and the bonding strength (adhesion) due to the anchor effect is improved.

It should be noted that the present invention is not limited to the concave portions shown in the second embodiment of the present invention, but may have the forms shown in FIGS. Further, in the second embodiment of the present invention, the recess is formed by half etching, but may be formed by press working. Further, in the second embodiment of the present invention, the concave portion is formed as the conductive bonding material accumulation portion. However, the concave portion may be formed by a rough surface portion, or the rough surface portion and the concave portion may be combined.

A third embodiment of the present invention will be described by taking a monolithic crystal filter as an example with reference to FIGS. FIG. 5A is a front view showing the inside of the cap and a part of the base of the monolithic crystal filter.
FIG. 5B is a side view of FIG. FIG. 5C shows FIG.
It is a top view of (a). FIG. 6 is a plan view of a center support body showing a modification of the third embodiment of the present invention. The same parts as those in the second embodiment are denoted by the same reference numerals.

The piezoelectric vibrating plate 90 is an AT-cut quartz plate, is processed into a circular shape as a whole, and the upper end is flattened. On the surface, input electrodes 91 and output electrodes 92 are provided in parallel and closely spaced at a predetermined interval, and lead electrodes 91a and 92a are drawn from the respective electrodes to the end face of the piezoelectric vibrating plate. On the back surface, the input electrode and the output electrodes 91 and 9 are provided.
2, two common electrodes (not shown) are provided,
An extraction electrode 9 is provided from each electrode to the lower end face of the piezoelectric vibrating plate.
3a is pulled out. These common electrodes are externally connected in common. The base supporting this piezoelectric diaphragm is
It comprises a base body 8 and a support body. Base body 8
The lead terminals 81 and 83 are insulated and implanted in a metal shell 80 via a glass 80a.
2 is directly connected to the shell, and lead terminals 8
A slit 84a (the other is not shown) is provided on the upper portion of each of the first and second portions 83, and a rough surface portion 84 as a conductive bonding material storage portion.
Plate-like supports 84 and 86 on which b (the other is not shown) are formed are attached by means such as spot welding. The slit 84a can be formed by, for example, pressing, and the rough surface portion 84b can be formed by, for example, polishing. Further, a center support body 87 is spot-welded to the center of the upper surface of the base body in an inclined state. A rough surface portion 87b as a conductive bonding material accumulation portion is formed by polishing or the like at a portion where the piezoelectric vibration plate contacts the upper flat surface of the center support body 87. The extraction electrodes 91a and 92a of the piezoelectric vibrating plate are supported by supports 84 and 86, and are electrically conductively bonded by a conductive bonding material S. In addition, the extraction electrode 93a on the common electrode side and the plane portion above the center support body 87 are conductively joined, and finally, the conduction is made to the lead terminal 82 serving as a ground terminal. Then, the piezoelectric vibrating plate 90, the support members 84 and 86, the center support member 87 and the like are covered with the cap 3, and hermetically sealed.

In the third embodiment of the present invention, the support 8
The rough surface portions 84b and 87b (partly not shown) provided on the center support body 87 prevent the conductive bonding material from flowing out of the rough surface portion of the support body. In particular, the conductive bonding material no longer flows downward (in the direction of gravity) due to gravity. Then, the position of the conductive bonding material is determined, the dispersion can be stably eliminated, and the bonding strength (adhesion) due to the anchor effect is improved.

Although the rough surface is formed by polishing in the third embodiment of the present invention, it may be formed by etching or pressing. Further, in the third embodiment of the present invention, the support body and the center support body are formed with the rough surface portion as the conductive bonding material reservoir, but may be formed by the concave portion, and the rough surface portion and the concave portion are combined. You may. For example, the forms shown in FIGS. 6A to 6H can be considered (only the center support is illustrated, but it is needless to say that the present invention can also be applied to a support body).

In the above embodiment, a quartz plate is taken as the piezoelectric vibrating plate. However, there is no particular problem if a piezoelectric single crystal material such as piezoelectric ceramics or lithium tantalate is used.

[0026]

According to the first aspect, the application position of the conductive bonding material is set in the pool portion to eliminate the variation and serve as a mark for positioning. In addition, variations in the application amount of the conductive bonding material are eliminated, and fluctuations in the CI value (crystal impedance) and the frequency temperature characteristic with respect to the initial setting as the piezoelectric device are not caused. The pool prevents the conductive bonding material from flowing out of the support (from the desired application position in the downward direction), and eliminates poor conduction and poor bonding. Then, the bonding strength (adhesion) of the conductive bonding material is improved by the anchor effect of the pool portion.

According to the second aspect, the application position of the conductive bonding material is set to the rough surface portion to eliminate the variation and serve as a mark for positioning. In addition, variations in the application amount of the conductive bonding material are eliminated, and fluctuations in the CI value (crystal impedance) and the frequency temperature characteristic with respect to the initial setting as the piezoelectric device are not caused. Then, the rough surface portion prevents the conductive bonding material from flowing out of the support (the conductive bonding material from a desired application position in the downward direction), thereby eliminating conduction failure, bonding failure, and the like. Then, the bonding strength (adhesion) of the conductive bonding material is improved by the anchor effect of the rough surface portion.

According to the third aspect, the application position of the conductive bonding material is set at the concave portion to eliminate the variation and serve as a mark for positioning. In addition, variations in the application amount of the conductive bonding material are eliminated, and fluctuations in the CI value (crystal impedance) and the frequency temperature characteristic with respect to the initial setting as the piezoelectric device are not caused. Then, the concave portion prevents the conductive bonding material from flowing out of the support (the conductive bonding material from a desired application position in a downward direction), thereby eliminating conduction failure, bonding failure, and the like. Then, the bonding strength (adhesion) of the conductive bonding material is improved by the anchor effect of the concave portion.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment.

FIG. 2 is a diagram showing a modification of the first embodiment.

FIG. 3 is a diagram showing a second embodiment.

FIG. 4 is a diagram showing a modification of the second embodiment.

FIG. 5 is a diagram showing a third embodiment.

FIG. 6 is a diagram showing a modification of the third embodiment.

FIG. 7 is a diagram showing a conventional example.

[Explanation of symbols]

 2, 8 ... base body 3 ... cap 10, 90 ... crystal plate (piezoelectric vibration plate) 11 ... excitation electrode 24, 26, 84, 86 ... support body 85, 87 ... Center support body 91: input electrode 92: output electrode S: conductive bonding material

Claims (3)

[Claims] 1. A base on which at least two lead terminals are implanted insulated from each other, a support body attached to each of the lead terminals, a piezoelectric diaphragm having excitation electrodes formed on the front and back surfaces, A conductive bonding material for electromechanically bonding the support body and the piezoelectric vibration plate, and at least a cap for hermetically sealing the piezoelectric vibration plate, wherein the piezoelectric vibration plate is disposed on a plane of the support body. In the support structure of a piezoelectric vibration device mounted vertically, at least a portion of the support body where a conductive bonding material is applied is formed at a portion where the conductive bonding material is applied. Support structure. 2. A base on which at least two lead terminals are implanted insulated from each other, a support body attached to each of the lead terminals, a piezoelectric vibrating plate having excitation electrodes formed on the front and back surfaces, A conductive bonding material for electromechanically bonding the support body and the piezoelectric vibration plate, and at least a cap for hermetically sealing the piezoelectric vibration plate, wherein the piezoelectric vibration plate is disposed on a plane of the support body. A support structure for a piezoelectric vibration device mounted vertically, wherein a rough surface is formed at least in a portion of the support body to which the conductive bonding material is applied. 3. A base having at least two lead terminals implanted insulated from each other, a support body attached to each of the lead terminals, a piezoelectric diaphragm having excitation electrodes formed on the front and back surfaces, A conductive bonding material for electromechanically bonding the support body and the piezoelectric vibration plate, and at least a cap for hermetically sealing the piezoelectric vibration plate, wherein the piezoelectric vibration plate is disposed on a plane of the support body. A support structure for a vertically mounted piezoelectric vibration device, wherein at least one concave portion is formed in at least a portion of the support body where the conductive bonding material is applied. Construction.