JPH0738375A - Piezoelectric resonance component - Google Patents

Abstract

PURPOSE:To provide a ladder type piezoelectric resonance component of case housing type of thin shape, with high mass-productivity, and capable of setting the connection point of a terminal member with a piezo-resonator with high accuracy. CONSTITUTION:A case 1 is provided with internal space 11. The piezo-resonators 21-24 are provided with electrodes on both planes of a piezoelectric ceramics material body. The terminal members 31-34 are formed with flat metallic members, and are provided with conductive projections 41-48 in the planes. The piezo-resonators 21-24 and the terminal members 31-34 are arranged in the internal space 11 by superimposing so as to comprise a ladder circuit. The conductive projections 41-48 of the terminal members 31-34 come in contact with the electrodes of the piezo-resonators 21-24, and a gap is generated between the piezo-resonators 21-24 and the terminal members 31-34 at an area except for the contact part of the conductive projections 41-48.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric resonance component used for a ladder type ceramic filter or the like.

[0002]

2. Description of the Related Art Piezoelectric resonance components of this type are disclosed, for example, in Japanese Utility Model Publication No. 4-119130, Japanese Utility Model Publication No. 5-4622, and Japanese Utility Model Publication No. 5622.
No. 4623 and Japanese Utility Model Laid-Open No. 5-4624 are disclosed. As a basic configuration, a plurality of piezoelectric resonators,
The piezoelectric resonator and the terminal member are stacked so as to form a ladder circuit, and the assembly thereof is arranged in the internal space of the case. Each of the piezoelectric resonators is a flat plate-shaped element that utilizes the surface-spreading vibration mode,
Each of the terminal members comes into contact with the piezoelectric resonator at a node generated on the surface of the piezoelectric resonator, and the portions other than the contact points are arranged apart from the surface of the piezoelectric resonator. The terminal member is made of a metal plate material and is formed in advance into a shape required for lamination with the piezoelectric resonator. Further, the terminal member has a protrusion formed by pressing a metal plate material from one surface side to the other surface side as a contact portion with the piezoelectric resonator.

[0003]

The above-described conventional piezoelectric resonance component has some points to be improved in terms of further thinning and improvement in mass productivity. For example, since the terminal member is formed by folding the metal plate in a double manner so as to be folded back, the thickness of the terminal member is twice or more the plate thickness. Further, since the metal plate is bent, mass productivity is poor. Furthermore, since the terminal member forms a protrusion by pressing the metal plate from one surface side to the other surface side as a contact portion with the piezoelectric resonator, the position of the protrusion depends on the position accuracy at the time of pressing and bending. And fluctuate. Therefore, it is difficult to maintain the positional accuracy of the protrusions with high accuracy. The displacement of the protrusions causes fluctuations in the piezoelectric resonance characteristics.

An object of the present invention is to provide a case-type ladder-type piezoelectric resonance component.

Another object of the present invention is to provide a piezoelectric resonance component which can minimize the influence of the terminal member on the surface expansion vibration mode of the piezoelectric resonator. Another object of the present invention is to provide a piezoelectric resonance component which is thin and has high mass productivity.

Another object of the present invention is to provide a piezoelectric resonance component which can set the contact point with the piezoelectric resonator with high accuracy.

[0007]

In order to solve the above problems, the present invention provides a piezoelectric resonance component including a case, a plurality of piezoelectric resonators, and a plurality of terminal members, wherein the case has an internal space. The piezoelectric resonator has electrodes on both sides of the piezoelectric ceramic body, and the terminal member is made of one flat metal plate and has conductive protrusions in the plane. , Having another conductive projection or a flat surface on the back surface side of the conductive projection, the piezoelectric resonator and the terminal member are arranged in the internal space to be stacked so as to form a ladder circuit, The conductive protrusion of the terminal member contacts the electrode of the piezoelectric resonator, and a space is created between the piezoelectric resonator and the terminal member in a region excluding the contact portion of the conductive protrusion.

[0008]

Since the piezoelectric resonator and the terminal member are overlapped with each other so as to form a ladder circuit and arranged in the internal space, a case type ladder-type piezoelectric resonance component can be obtained.

The terminal member is made of one flat metal plate,
Since the metal plate has the conductive protrusions in the plane, the double-folded structure is unnecessary unlike the conventional case. For this reason, it becomes thin and mass productivity improves.

The terminal member has a conductive projection on the surface of the metal plate, and has a flat surface formed by another conductive projection or a metal plate on the back surface side of the conductive projection. In the terminal member having such a structure, a conductive protrusion is formed by adhering a metal on the surface by means such as electric or chemical plating, or a conductive protrusion is formed by the terminal member itself. It can be obtained by means of. The means for forming the conductive protrusions by the terminal member itself can be obtained by chemically etching or electropolishing the surface of the terminal member except the region where the conductive protrusions are to be formed. Electrical or chemical plating, chemical etching, or electrolytic polishing can form a required pattern with high accuracy. Therefore, it is possible to set the conductive protrusion serving as a contact point with the piezoelectric resonator with high accuracy.

The piezoelectric resonator has electrodes on both sides of the piezoelectric ceramic body, the piezoelectric resonator and the terminal member are stacked so as to form a ladder circuit, and the conductive protrusions of the terminal member are piezoelectric resonators. Since there is a space between the piezoelectric resonator and the terminal member in a region in which the conductive protrusion is in contact with the electrode, the influence of the terminal member on the vibration mode of the piezoelectric resonator is reduced. It can be minimized by keeping the spacing by.

[0012]

1 is an exploded perspective view of a piezoelectric resonance component according to the present invention, FIG. 2 is a partial sectional view of the piezoelectric resonance component according to the present invention shown in FIG. 1, and FIG. 3 is a line A3-A3 in FIG. It is a plane sectional view. Reference numeral 1 is a case, reference numerals 21 to 24
Is a piezoelectric resonator, reference numerals 31 to 34 are terminal members, and reference numerals 41 to 48 are conductive protrusions. The case 1 has an internal space 11. The internal space 11 is open on one side of the case 1. The opening is filled with the insulating sealing resin 6. A terminal lead-out hole 12 (see FIG. 1) is provided at the bottom of the case 1 on the side opposite to the opening side where the insulating sealing resin 6 is filled.
Is provided.

Each of the piezoelectric resonators 21 to 24 has a structure in which electrodes are provided on both sides in the thickness direction of a flat piezoelectric ceramic body. The piezoelectric resonators 21 to 24 are preferably elements that utilize the surface expansion vibration mode. In the surface-spreading vibration mode piezoelectric resonators 21 to 24, the piezoelectric ceramic body is polarized so as to generate an electrostrictive phenomenon in a diagonal direction when an electric field is applied between electrodes on both surfaces. In the face-spreading vibration mode, a node is generated at the center of the plane of the piezoelectric ceramic body.
It is also possible to use a piezoelectric resonator that uses a length vibration mode in addition to the surface expansion vibration mode.

Each of the terminal members 31 to 34 is made of, for example, a copper plate or a phosphor bronze plate having a plate thickness of about 0.1 mm. Each of the terminal members 31 to 34 is
It has conductive protrusions 41 to 48 in the plane. Terminal member 3
Among the members 1 to 34, the terminal member 31 has a structure in which a first metal plate 311 and a second metal plate 312 facing each other with a space therebetween are connected by a connecting piece 313. Both the first metal plate 311 and the second metal plate 312 have a flat plate shape, and have conductive protrusions 41 to 43 at substantially central portions within their planes. The terminal member 32 has a metal plate 321, and has conductive protrusions 44 and 45 at substantially the center of its surface. The terminal member 33 has a metal plate 331, and has conductive protrusions 46 and 47 at approximately the center of the surface thereof. The terminal member 34 is the metal plate 3
41, and the conductive protrusion 48 is provided in the approximate center of the surface. Reference numerals 323 to 343 are terminal portions.

The conductive protrusions 41 to 48 have a height of 0.05.
It is around mm. Such protrusions 41 to 48 can be formed on the surfaces of the terminal members 31 to 34 by attaching metal by means such as selective plating or by the terminal members 31 to 34 themselves. As means for forming the conductive protrusions 41 to 48 by the terminal members 31 to 34 themselves, the surfaces of the terminal members 31 to 34 are chemically etched or electrolyzed except for the regions where the conductive protrusions 41 to 48 are to be formed. It can be obtained by polishing. The required pattern can be formed with high accuracy by electrical or chemical plating, chemical etching or electrolytic polishing. The conductive protrusions 41 to 48 may have a polygonal shape, and the piezoelectric resonator 21.
To 24 and the terminal members 31 to 34 are stacked so as to form a ladder circuit and are arranged in the internal space 11. It is desirable that the piezoelectric resonators 21 to 24 are arranged so that at least the periphery thereof is separated from the inner wall surface of the internal space 11. Piezoelectric resonators 21 to 21 for forming a ladder circuit
24 and the terminal members 31 to 34 are specifically arranged in terms of the first metal plate 311 and the second metal plate 3 provided on the terminal member 31.
12, the piezoelectric resonator 21, the terminal piece 32, the piezoelectric resonator 22, the terminal piece 33, and the piezoelectric resonator 23 are inserted in this order, and the second metal plate 312 of the terminal member 31 and the inside of the case 1 are inserted. Insert the terminal member 34 in the space between the wall surface,
The piezoelectric resonator 2 is provided between the terminal member 34 and the second metal plate 312.
It is a structure in which 4 is inserted. Terminal part 3 of the terminal pieces 32 to 34
23 to 343 are drawn out of the case 1 and bent in the same direction along the outer surface of the case 1. As a result, a planar mounting type piezoelectric resonance component is obtained. Reference numeral 7 in FIG.
Is a sealing resin. Although not shown, the number, arrangement and size of the piezoelectric resonators are arbitrary. The same applies to the terminal member.

As shown in the enlarged view of FIG. 4, the conductive protrusions 41 to 48 are in contact with the electrodes 210 of the piezoelectric resonators 21 to 24, and the piezoelectric resonance occurs in a region other than the contact portions of the conductive protrusions 41 to 48. Gap G1, G2 is produced between the child 21-24 and the terminal members 31-34. The intervals G1 and G2 are around 0.05 mm which is the height of the conductive protrusions 41 to 48. When an element using the surface expansion vibration mode is selected as the piezoelectric resonators 21 to 24, the conductive protrusions 41 to 48 are formed.
Contacts the electrode 210 on a node that occurs on the faces of the piezoelectric resonators 21-24. In FIG. 4, reference numeral 200 is a piezoelectric ceramic body.

FIG. 5 is an electrical symbol diagram of the piezoelectric resonance component according to the present invention. The piezoelectric resonators 21 and 24 are series resonators, the piezoelectric resonators 22 and 23 are parallel resonators, the terminal portion 323 of the terminal member 32 is an output terminal, and the terminal portion 333 of the terminal member 33 is a ground terminal. Terminal portion 34
A ladder connection circuit having 3 as an input terminal can be obtained.

As described above, since the piezoelectric resonators 21 to 24 and the terminal members 31 to 34 are stacked and arranged in the internal space so as to form a ladder circuit, a case-accommodating ladder type piezoelectric resonance. Parts are obtained.

Since the terminal members 31 to 34 are made of one flat metal plate and have the conductive protrusions 41 to 48 in the plane, unlike the conventional case, the double folding structure is unnecessary.
For this reason, it becomes thin and mass productivity improves.

The terminal members 31 to 34 have the conductive protrusions 41 to 48 in the plane, and have other conductive protrusions or planes on the back side of the conductive protrusions 41 to 48. The terminal members 31 to 34 having such a structure can be formed by high-precision pattern forming technology such as electrical or chemical plating, chemical etching, or electrolytic polishing. Therefore, it is possible to set the conductive protrusion serving as a contact point with the piezoelectric resonator with high accuracy.

The piezoelectric resonators 21 to 24 are piezoelectric ceramic body 20.
0 has electrodes 210 on both sides, and piezoelectric resonators 21 to
24 and the terminal members 31 to 34 are stacked so as to form a ladder circuit, the conductive protrusions 41 to 48 of the terminal members 31 to 34 contact the electrodes 210 of the piezoelectric resonators 21 to 24, and the conductive protrusions 41. In the region excluding the contact portions of ~ 48, the gaps G1, G2 are generated between the piezoelectric resonators 21-24 and the terminal members 31-34. Therefore, the piezoelectric resonator 2
The influence of the terminal member on the vibration modes of 1 to 24 can be minimized by the spacing maintained by the conductive protrusions 41 to 48.

As the piezoelectric resonators 21 to 24, those of ordinary type can be used, and the electrode 210 (see FIG. 4) attached to the piezoelectric ceramic body 200 is made of a Cu-Ni alloy, N.
It is also effective to use at least one of i-Cr alloy and Cr-Si alloy. Electrodes made of these alloys have excellent oxidation resistance, sulfidation resistance and corrosion resistance, and there is no room for silver migration. For this reason,
Electrodes 210 of piezoelectric resonators 21-24 and terminal members 31-3
It is possible to obtain a highly reliable piezoelectric resonance component that is less likely to cause poor contact with the piezoelectric resonance component.

Further, the electrode 210 made of at least one of Cu-Ni alloy, Ni-Cr alloy and Cr-Si alloy has an effective electric resistance value when used as a filter, so that the piezoelectric vibration is effective. Since the Q value of the child is lowered, the group delay characteristic can be improved.
Therefore, the group delay characteristic can be improved without using a resistor.

FIG. 6 is a partial sectional view showing still another embodiment of the piezoelectric resonance component according to the present invention, and FIG. 7 is a sectional view taken along the line A7-A7 of FIG. In this embodiment, the positioning means 91-91
With 94. The positioning means 91 to 94 are elastic resin or expandable elastic resin filled in the positions corresponding to the nodes generated around the piezoelectric resonators 21 to 24. As an example of such a resin, a silicon-based resin can be cited. Since the illustrated piezoelectric resonators 21 to 24 have a rectangular shape, a total of four nodes are formed in the widthwise intermediate portion and the lengthwise intermediate portion of the piezoelectric resonators 21 to 24. The positioning means 91 to 94 are formed by applying an elastic resin or a foamable elastic resin to each of these nodes and curing it. It is desirable that the application width of the elastic resin or the expandable elastic resin be formed as narrow as possible within a range in which necessary mechanical strength can be secured.

Since the positioning means 91 to 94 are made of elastic resin or expandable elastic resin filled in the space, the elastic resin or expandable elastic resin is in close contact with the piezoelectric resonators 21 to 24 and the terminal members 31 to 34. , Piezoelectric resonators 21-2
4 and the terminal members 31 to 34 can be surely prevented from being displaced and illegally arranged.

Further, externally applied vibrations and drop impacts are absorbed by the elasticity of the elastic resin or the foamable elastic resin forming the positioning means 91 to 94, and the piezoelectric resonators 21 to.
It is possible to reliably prevent the positional deviation and the improper arrangement of the terminal 24 and the terminal members 31 to 34.

Further, since the positioning means 91 to 94 are filled at the positions corresponding to the nodes generated in the peripheral portions of the piezoelectric resonators 21 to 24, the positioning means 91 to 94 are provided.
It is possible to minimize vibration disturbance to the piezoelectric resonators 21 to 24 due to.

FIG. 8 is a partial sectional view showing still another embodiment of the piezoelectric resonance component according to the present invention, and FIG. 9 is a sectional view taken along the line A9-A9 of FIG. The positioning means 91 to 93 include positions corresponding to nodes generated in the peripheral portions of the piezoelectric resonators 21 to 24, and the piezoelectric resonators 21 to 24 and the terminal members 31 to 34.
The conductive protrusions are provided in the space along the stacking direction of. The positioning means 91 to 93 may be formed in the same body as the case 1, or may be a component separate from the case 1 and assembled at a predetermined position. Further, it is desirable that the width be formed as narrow as possible within a range in which necessary mechanical strength can be secured.

With the above structure, the positioning means 91-9
3, the piezoelectric resonators 21 to 24 and the terminal members 31 to 3
It is possible to surely prevent the positional deviation and the improper arrangement of No. 4. In addition, the positioning means 91-94 are provided with the piezoelectric resonators 21-24.
Since the piezoelectric resonator 21 is arranged at a position corresponding to a node generated in the peripheral portion of the piezoelectric resonator 21 by the positioning means 91 to 94.
Vibration disturbances to ~ 24 can be minimized.

In the embodiment, the case 1 has an opening on one end side when viewed in the width direction, and the piezoelectric resonators 21 to 24 are provided.
And the terminal members 31 to 34 are passed through the openings to form the case 1
It is designed to be inserted inside. Under such a structure, the positioning means 91 to 93 are arranged on one end side in the lateral width direction on the side opposite to the opening side and on both sides in the longitudinal width direction. Therefore, the piezoelectric resonators 21 to 24 are provided in the case 1.
And the piezoelectric resonator 2 only by inserting the terminal members 31 to 34.
1 to 24 are subjected to the positioning action by the positioning means 91 to 93. Unlike the embodiment, the positioning means 91 to 9
3 can also be arranged at one end side in the lateral width direction opposite to the opening side and one end side in the longitudinal width direction. Also in this case,
The piezoelectric resonators 21 to 24 can be positioned at predetermined positions in the case 1.

FIG. 10 is a partial sectional view showing still another embodiment of the piezoelectric resonance component according to the present invention, and FIG. 11 is A11 of FIG.
-It is sectional drawing on the A11 line. In this embodiment, among the plurality of piezoelectric resonators 21 to 24 provided, the piezoelectric resonators 21 and 24 are smaller in horizontal width and vertical width than the piezoelectric resonators 22 and 23 by dimensional differences d1 and d2. Further, on the side facing the piezoelectric resonators 21 to 24 and the terminal members 31 to 34, step portions a and b having steps corresponding to the dimensional differences d1 and d2 of the horizontal width or the vertical width are provided. The steps a and b control the nodes generated on the surfaces of the piezoelectric resonators 21 to 24 in a direction in which the piezoelectric resonators coincide with each other. Positioning means 9
1 to 93 may be formed integrally with the case 1, or may be separate parts from the case 1 and assembled at predetermined positions. Further, it is desirable that the width be formed as narrow as possible within a range in which necessary mechanical strength can be secured.

Of the plurality of piezoelectric resonators 21 to 24 provided, the piezoelectric resonators 21 and 24 are smaller in width and length than the piezoelectric resonators 22 and 23 by the dimensional differences d1 and d2. Depending on the size of the children 21 to 24, high selectivity can be achieved and group delay characteristics can be improved.

The positioning means 91 to 93 are the piezoelectric resonator 2
1 to 24 and the terminal members 31 to 34 along the stacking direction, the case 1, the piezoelectric resonators 21 to 24, and the terminal members 31 to 34.
And stepped portions a and b having a step corresponding to the dimensional differences d1 and d2 in horizontal and vertical widths are provided on the side facing the piezoelectric resonators 21 to 24 and the terminal members 31 to 34, respectively. ,
The step portions a and b control the nodes generated on the surfaces of the piezoelectric resonators 21 to 24 in a direction in which the piezoelectric resonators coincide with each other. Therefore, the piezoelectric resonators 21 and 24 and the piezoelectric resonators 22 and 23 having different sizes are controlled. , The nodes generated on the surfaces of the piezoelectric resonators 21 to 24 can be reliably matched.
Therefore, it is possible to prevent fluctuations in resonance impedance and generation of unnecessary vibration modes, and obtain desired characteristics. Further, the positioning means 91 to 93 prevent the piezoelectric resonators 21 to 24 and the terminal members 31 to 34 from being displaced due to vibrations applied from the outside or a drop impact, and the piezoelectric resonators 21 to 31.
It is possible to reliably prevent the positional deviation and the improper arrangement of the terminal 24 and the terminal members 31 to 34.

Also in the embodiments of FIGS. 6 to 11, the terminal members 31 to 34 are made of flat metal members and have the conductive protrusions 41 to 48 in the plane, and the piezoelectric resonances 21 to 24 and the terminals. The members 31 to 34 are stacked so as to form a ladder circuit and arranged in the internal space 11, and the terminal members 31 to 34 are arranged.
Of the conductive protrusions 41 to 48 contact the electrodes of the piezoelectric resonators 21 to 24, and the piezoelectric resonators 21 to 24 and the terminal members 31 to 31 are formed in a region except the contact portions of the conductive protrusions 41 to 48.
Since there is a gap between the four, the same effect as the embodiment shown in FIGS. 1 to 5 can be obtained.

[0035]

As described above, according to the present invention, the following effects can be obtained. (A) A case-type ladder-type piezoelectric resonance component can be provided. (B) The double folding structure is unnecessary. Therefore, it is possible to provide a thin piezoelectric resonance component having excellent mass productivity. (C) It is possible to provide a piezoelectric resonance component in which conductive protrusions that are contact points with the piezoelectric resonator are set with high accuracy. (D) It is possible to provide a piezoelectric resonance component that can minimize the influence of the terminal member on the vibration mode of the piezoelectric resonator.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a piezoelectric resonance component according to the present invention.

FIG. 2 is a partial front sectional view of a piezoelectric resonance component according to the present invention.

3 is a cross-sectional view taken along the line A3-A3 in FIG.

FIG. 4 is an enlarged cross-sectional view showing a contact structure between a piezoelectric resonator and a terminal member.

FIG. 5 is an electrical symbol diagram of the piezoelectric resonance component according to the present invention.

FIG. 6 is a partial sectional view showing still another embodiment of the piezoelectric resonant component according to the present invention.

7 is a cross-sectional view taken along the line A7-A7 of FIG.

FIG. 8 is a partial sectional view showing still another embodiment of the piezoelectric resonant component according to the present invention.

9 is a cross-sectional view taken along the line A9-A9 of FIG.

FIG. 10 is a partial sectional view showing still another embodiment of the piezoelectric resonant component according to the present invention.

11 is a cross-sectional view taken along the line A11-A11 of FIG.

[Explanation of symbols]

 1 Case 11 Internal Space 21-24 Piezoelectric Resonator 31-34 Terminal Member 41-48 Conductive Protrusion

Front Page Continuation (72) Inventor Takashi Yamamoto 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation (72) Inventor Satoshi 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside TDC Corporation

Claims (5)

[Claims] 1. A piezoelectric resonance component including a case, a plurality of piezoelectric resonators, and a plurality of terminal members, wherein the case has an internal space, and the piezoelectric resonator is a piezoelectric ceramic element. It has electrodes on both sides of the body, the terminal member is made of one flat metal plate, has a conductive protrusion in the plane, the other conductive protrusion on the back side of the conductive protrusion or The piezoelectric resonator and the terminal member are arranged in the internal space so as to be stacked so as to form a ladder circuit, and the conductive protrusion of the terminal member has a flat surface. A piezoelectric resonance component in which a gap is generated between the piezoelectric resonator and the terminal member in a region that contacts an electrode and excludes a contact portion of the conductive protrusion. 2. The piezoelectric resonator is a flat plate-shaped element that utilizes a surface expansion vibration mode, and the terminal member contacts the electrode at a node where the conductive protrusion is formed on the surface of the piezoelectric resonator. The piezoelectric resonance component according to claim 1, wherein 3. The piezoelectric resonance component according to claim 1, wherein the conductive protrusion is made of a conductive member attached to the surface of the terminal member by a conductive resin or a conductive adhesive. 4. The piezoelectric resonance component according to claim 1, wherein the conductive protrusion is formed by the terminal member itself. 5. The piezoelectric resonance component according to claim 1, wherein the conductive protrusion is formed by selective plating.