JPH06140869A - Piezoelectric part and manufacture of the same - Google Patents

Abstract

PURPOSE:To provide the piezoelectric parts and the manufacture of the same which simplify the structure, facilitate the manufacture and are suitable for the manufacture of the multiple types of articles. CONSTITUTION:A piezoelectric oscillator 1 is provided with oscillating electrodes 102, and 103, which are faced each other, on both faces of a piezoelectric substrate 101, and an oscillation part is composed of the oscillating electrodes 102 and 103. Armour bodies 2 and 3 are composed of adhesive agents setting spacers 21 and 31 from a B stage and adhered onto the surface of the piezoelectric substrate 101 while surrounding the periphery of the oscillation part, seal films 22 and 32 are stuck to the end faces of spacers 21 and 31, and a void formed around the oscillation part is sealed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric component, and more particularly to a piezoelectric component which has a simple structure, is easy to manufacture, and is suitable for multi-product manufacturing, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Piezoelectric parts such as ceramic filters, ceramic resonators, trap elements or discriminators have piezoelectric vibrating electrodes formed on both sides of a piezoelectric substrate to secure a vibrating space that does not cause vibration interference. Need to support. Various techniques have been conventionally proposed as means for this. For example, in Japanese Unexamined Patent Publication No. 54-74696, a space is formed by covering a periphery of a resonator with a laminate film having a stretching ratio of 250% or more, and the laminate film is provided with an exterior resin. In addition, JP-A-57
According to Japanese Patent Publication No. 142016, paraffin wax is applied to a portion corresponding to a vibration region, and then an insulating resin coating such as porous epoxy resin is applied to the whole portion, and then heat treatment is performed to vaporize the paraffin wax and There is known a technique for forming a cavity in the. The vaporized paraffin wax is discharged to the outside through the pores of the porous insulating resin coating.

[0003]

However, the above-described conventional piezoelectric component and its manufacturing method are not necessarily suitable for miniaturization and multi-product manufacturing because the cavity structure and the cavity forming process are relatively complicated. . Further, in order to discharge the vaporized paraffin wax to the outside, the insulating resin coating layer of epoxy resin or the like must be a porous layer, so that the airtightness becomes insufficient and the reliability is lowered. Invite. The paraffin wax is not completely discharged to the outside, and the paraffin wax is likely to remain in the cavity. If this residual paraffin wax is oxidized, it may corrode the electrode material, in which case the characteristics will deteriorate. Electrode erosion and characteristic deterioration due to residual paraffin wax are likely to appear at high temperatures.

Therefore, an object of the present invention is to solve the above-mentioned conventional problems, and to provide a piezoelectric component which has a simple structure and is easy to manufacture, and which is suitable for multi-product manufacturing, and a manufacturing method thereof.

[0005]

In order to solve the above-mentioned problems, the present invention is a piezoelectric component including a piezoelectric vibrator and an outer package, wherein the piezoelectric vibrator faces each other on both sides of a piezoelectric substrate. The vibrating electrode has a vibrating electrode, the vibrating electrode constitutes a vibrating portion, the exterior body has a spacer and a sealing film, and the spacer is constituted by an adhesive layer cured from a B stage. The sealing film is adhered to the surface of the piezoelectric substrate so as to surround the portion and is adhered to the end surface of the spacer to seal the cavity formed around the vibrating portion by the spacer.

A manufacturing method according to the present invention for obtaining the above-mentioned piezoelectric component includes at least two steps, and the first step is a method of manufacturing a piezoelectric component, wherein the first step is a piezoelectric element having a large number of vibrating parts. The step of laminating and adhering the outer casing having the B-stage adhesive layer on one surface of the sealing film on the substrate and adhering the same, and the second step is the step of dividing each vibrating portion.

[0007]

[Function] The piezoelectric vibrator has the vibrating electrodes facing each other on both sides of the piezoelectric substrate, and the vibrating electrodes form the vibrating portion. The exterior body is adhered to the surface of the piezoelectric substrate with the spacer surrounding the vibrating portion. Since the sealing film is attached to the end surface of the spacer to seal the cavity formed around the vibrating portion by the spacer, a piezoelectric component in which a vibrating space that does not cause a vibration failure is secured by the cavity can be obtained.

Since the spacer is composed of an adhesive layer and is adhered to the surface of the piezoelectric substrate and the sealing film is adhered to the end surface of the spacer, the outer package has a small number of parts.

Since the spacer is composed of the adhesive layer cured from the B stage, it is possible to reduce the fluctuation of the cavity volume due to the crushing and the protrusion of the spacer. Therefore, the reliability of the cavity is improved. Moreover, since the resin components of the B-stage adhesive partly react to increase the melting point and become solid at room temperature, they are easy to handle. This facilitates manufacturing.

[0010]

1 is a sectional view of a piezoelectric component according to the present invention.
In the figure, 1 is a piezoelectric vibrator, 2 and 3 are exterior bodies, 4 and 5.
Is a cavity, and 6 and 7 are lead conductors. The piezoelectric vibrator 1 is
The vibrating electrodes 102 are provided on both surfaces of the plate-shaped piezoelectric substrate 101.
The vibrating electrodes 102 and 103 form a vibrating portion. 104 and 105 are lead electrodes. The lead electrode 104 is electrically connected to the vibrating electrode 102, and the lead electrode 10
Reference numeral 5 is electrically connected to the vibrating electrode 103. One end of the lead conductor 6 is fixed to the lead electrode 104 with a conductive adhesive, and the other end is led out of the exterior body 2. One end of the lead conductor 7 is fixed to the lead electrode 105 with a conductive adhesive, and the other end is led out of the exterior body 3. The lead conductor may be fixed by using a solder instead of a conductive adhesive.

The outer package 2 has a spacer 21 and a sealing film 22. The spacer 21 is composed of an adhesive layer of thermosetting resin cured from the B stage, surrounds the vibrating portion, and is bonded on the surface of the piezoelectric substrate 101.
As is well known, the technical term "B stage" is used in thermosetting resins together with the technical terms "A stage" and "C stage". Although the oligomer of the B stage resin grows linearly and side chains are formed, it is in a thermoplastic stage in which it melts when heat is applied. The B-stage resin is easy to handle because the resin component partially reacts to increase the melting point and becomes a solid state at room temperature. Also, it is remelted by heating. A typical example of the adhesive used in the present invention is a B-stage epoxy adhesive.

The sealing film 22 is attached to the end surface of the spacer 21 to seal the cavity 4 formed around the vibrating portion by the spacer 21. The exterior body 3 is also a spacer 31.
And a sealing film 32. The spacer 31 is composed of an adhesive layer cured from the B stage, surrounds the vibrating portion, and is bonded onto the surface of the piezoelectric substrate 101.
The sealing film 32 is attached to the end surface of the spacer 31 and seals the cavity 5 formed around the vibrating portion by the spacer 31. The sealing films 22 and 32 can be made of a metal plate or the like in addition to synthetic resin or ceramic.

As described above, the piezoelectric vibrator 1 is the piezoelectric substrate 1
01 has vibrating electrodes facing each other on both sides, and the vibrating electrodes form a vibrating portion.
31 surrounds the vibrating portion and is bonded to the surface of the piezoelectric substrate 101, and the sealing films 22 and 32 are the spacers 21 and 3.
Since the spacers 21 and 31 seal the cavities 4 and 5 formed around the vibrating portion, the cavities 4 and 5 are attached to the end face of 1.
With the cavities 4 and 5, it is possible to obtain a piezoelectric component that secures a vibration space that does not cause a vibration obstacle.

Since the spacers 21 and 31 of the outer casings 2 and 3 are made of an adhesive layer and are adhered to the surface of the piezoelectric substrate 101, and the sealing films 22 and 32 are attached to the end surfaces of the spacers 21 and 31, The number of parts is small.

Since the spacers 21 and 31 are composed of an adhesive layer cured from the B stage, the spacers 21 and 3 are
The change in the volume of the cavities 4 and 5 due to the crushing and the protrusion of 1 can be small. Therefore, the reliability of the cavity is improved. Moreover, since the resin components of the B-stage adhesive partly react to increase the melting point and become solid at room temperature, they are easy to handle.
This facilitates manufacturing.

FIG. 3 is a front sectional view showing another embodiment of the piezoelectric component according to the present invention. In the figure, the same reference numerals as those in FIGS. 1 and 2 denote the same components. The spacer 21 is a laminated body of at least three layers, and the intermediate layer 2
Adhesive layers 211, 2 capable of taking B stage on both sides of 10.
12 is attached. The spacer 31 is also a laminated body of three layers, and has a structure in which adhesive layers 311 and 312 capable of taking the B stage are attached to both sides of the intermediate layer 310. The material of the intermediate layers 210 and 310 is the sealing film 22,
The same as 32 is preferable. In the case of the embodiment shown in FIG. 3, the height of the cavities 4 and 5 can be increased in addition to the effects described in FIGS. 1 and 2.

Although not shown, in any of the embodiments, an insulating resin coating can be applied to the entire surface.

4 to 8 are views showing a method of manufacturing a piezoelectric component according to the present invention. This manufacturing method includes at least two steps. First, as shown in FIGS. 4 and 5, the piezoelectric substrate 101 having a large number of vibrating portions Q1 to Qn is manufactured. The piezoelectric substrate 101 has been subjected to necessary polishing, polarization treatment and electrode application steps.

Next, as shown in FIG. 6, the sealing film 22
4 and 5, the exterior body 2 having the B-stage spacer adhesive 21 on one side thereof and the exterior body 3 having the B-stage spacer adhesive 31 on one side of the sealing film 32 are shown in FIGS. The both surfaces of the substrate 101 are laminated and adhered. The spacer adhesives 21 and 31 are formed on the sealing film 22 so as to have a predetermined pattern, for example, by a printing process. The sealing films 22 and 32 can be made of resin or ceramic. When gluing,
Heat it. As a result, the B-stage adhesive 21,
31 is melted again and adheres to the surface of the piezoelectric substrate 101. Since the spacer adhesives 21 and 31 are at the B stage, the spacer adhesives 21 and 31 hardly crush or stick out in this heating step. For this reason,
The fluctuation of the volume of the cavity is small, and the reliability of the cavity is improved. Moreover, since the resin components of the B-stage adhesive partly react to increase the melting point and become solid at room temperature, they are easy to handle. This facilitates manufacturing.

Next, as shown in FIGS. 7 and 8, cutting lines (X1-X1)-(X4-X4) and (Y1-Y1)-
The vibrating parts Q1 to Qn are divided by (Y4−Y4). The dividing step is performed using a known cutting device.

After that, the piezoelectric component according to the present invention is obtained by performing necessary steps such as connecting lead conductors and resin molding.

In the embodiment, the piezoelectric component having a single vibrating part and the method of manufacturing the same are described.
The shape and structure are arbitrary. The present invention provides a piezoelectric component having another electrode structure, such as a ceramic filter, a ceramic resonator, a trap element or a discriminator,
It can also be applied to surface acoustic wave devices.

[0023]

As described above, according to the present invention, the following effects can be obtained. (A) The piezoelectric vibrator has vibrating electrodes facing each other on both sides of the piezoelectric substrate, and the vibrating electrodes form a vibrating portion, and in the exterior body, a spacer surrounds the vibrating portion and adheres to the surface of the piezoelectric substrate. Since the sealing film is attached to the end surface of the spacer to seal the cavity formed around the vibrating portion by the spacer, it is possible to provide the piezoelectric component in which the cavity ensures a vibrating space in which vibration is not disturbed. (B) In the outer package, the spacer is made of an adhesive layer and adhered to the surface of the piezoelectric substrate, and the sealing film is attached to the end surface of the spacer. Therefore, a piezoelectric component having a small number of components can be provided. (C) Since the spacer is composed of the adhesive layer cured from the B stage, it is possible to provide a highly reliable and high-quality piezoelectric component with less fluctuation of the cavity volume due to crushing and protrusion of the spacer. (D) Since the B-stage adhesive is solid at room temperature and is easy to handle, it is possible to provide a piezoelectric component that is easy to manufacture.

[Brief description of drawings]

FIG. 1 is a sectional view of a piezoelectric component according to the present invention.

FIG. 2 is a cross-sectional view taken along the line A2-A2 of FIG.

FIG. 3 is a sectional view of another embodiment of the piezoelectric component according to the present invention.

FIG. 4 is a plan view of a piezoelectric substrate used in the method of manufacturing a piezoelectric component according to the present invention.

5 is a cross-sectional view taken along the line A5-A5 of FIG.

FIG. 6 is a diagram showing a step of assembling an outer package with the piezoelectric substrate shown in FIGS. 4 and 5;

FIG. 7 is a plan view of the assembly after going through the process of FIG.

8 is a cross-sectional view taken along the line A8-A8 in FIG.

[Explanation of symbols]

 1 Piezoelectric vibrator 101 Piezoelectric substrate 102, 103 Electrode 2, 3 Exterior body 21, 31 Spacer 22, 32 Sealing film

Claims (4)

[Claims] 1. A piezoelectric component including a piezoelectric vibrator and an exterior body, wherein the piezoelectric vibrator has vibrating electrodes facing each other on both sides of a piezoelectric substrate, and the vibrating electrodes form a vibrating section. Wherein the exterior body has a spacer and a sealing film, the spacer is composed of an adhesive cured from the B stage, is surrounded by the vibrating portion, and is adhered to the surface of the piezoelectric substrate, A piezoelectric component in which a sealing film is attached to an end surface of the spacer to seal a cavity formed around the vibrating portion by the spacer. 2. The piezoelectric component according to claim 1, wherein the spacer is a laminated body of at least three layers, and an adhesive layer capable of taking a B stage is attached to both sides of the intermediate layer. 3. The piezoelectric component according to claim 2, wherein the material of the intermediate layer is the same as that of the sealing film. 4. The method according to claim 1, comprising at least two steps.
4. The method for manufacturing a piezoelectric component according to any one of 3 to 3, wherein the first step is to laminate and adhere an exterior body having a B-stage adhesive on one surface of a sealing film to a piezoelectric substrate having a large number of vibrating parts. The second step is a method of manufacturing a piezoelectric component, which is a step of dividing each of the vibrating portions.