JPH06188670A - Piezoelectric component and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a piezoelectric component and its manufacture suitable for the manufacture of lots of product kinds in which the structure is simple and the manufacture is easy. CONSTITUTION:A piezoelectric vibrator 1 has vibration electrodes 102 and 103 opposite to each other to both sides of a piezoelectric substrate 101 and the vibration electrodes 102 and 103 form the vibration part. Spacers 21 and 31 are formed to 1st outer packages 2 and 3 by an adhesives and adhered to a side of the piezoelectric substrate 101 while surrounding the vibration part and seal films 22 and 32 are adhered to an end face of the spacers 21 and 31 to seal a cavity formed around the vibration part. The 2nd outer package 8 is made of a resin to cover the surrounding of the 1st outer packages 2 and 3.

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. When this residual paraffin wax is oxidized, it may corrode the electrode material, in which case the characteristics 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, a first exterior body, and a second exterior body, wherein the piezoelectric oscillator comprises: The piezoelectric substrate has oscillating electrodes facing each other on both sides, the oscillating electrode constitutes an oscillating portion, the first exterior body has a spacer and a sealing film, and the spacer is an adhesive. Constituting around the vibrating portion and adhered to the surface of the piezoelectric substrate, the sealing film is attached on the spacer to seal the cavity formed around the vibrating portion by the spacer, The second exterior body is made of powder coating material and adheres to and covers the first exterior body.

In the manufacturing method according to the present invention for obtaining the above-mentioned piezoelectric component, the first step is a step of laminating and adhering an exterior body having an adhesive agent on one surface of the sealing film on a piezoelectric substrate and adhering the same. The step is a step of applying the powder coating material to the whole after the first step.

[0007]

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.
Since the spacer surrounds the vibrating portion and is bonded on the surface of the piezoelectric substrate and 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 obtain a piezoelectric component that secures a vibrating space that does not cause a vibration failure due to the cavity.

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

Since the second exterior body adheres to and surrounds the first exterior body to cover the first exterior body, a double protective structure for protecting the first exterior body with the second exterior body is obtained, and the cavity is deformed by external force and The airtightness of the cavity is less likely to decrease. Since the second exterior body is made of powder coating material, a piezoelectric component having excellent moisture resistance can be obtained.

The spacer preferably comprises an adhesive layer cured from the B stage. When the spacer is formed of the adhesive layer cured from the B stage, the spacer does not have to be crushed and the cavity volume can be prevented from fluctuating.
Therefore, the reliability of the cavity is improved. Moreover, in the B-stage adhesive, the resin component partially reacts to increase the melting point,
It is easy to handle because it becomes solid at room temperature. This facilitates manufacturing.

[0011]

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 first outer casings, 4 and 5 are cavities, 6 and 7 are lead conductors, and 8 is a second outer casing. The piezoelectric vibrator 1 has a plate-shaped piezoelectric substrate 101.
The vibrating electrodes 102 and 103 are provided on both surfaces of the vibrating electrode 1.
02 and 103 form a vibrating section. 104, 105
Is a lead electrode. The lead electrode 104 is the vibrating electrode 10.
2 and the lead electrode 105 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 first exterior body 2. The lead conductor 7 has one end fixed to the lead electrode 105 with a conductive adhesive and the other end led out to the outside of the first exterior body 3. The lead conductor may be fixed by using a solder instead of a conductive adhesive.

The first exterior body 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. B
The 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 sealing film 22 is, for example, a polyimide resin. The first 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.

The second exterior body 8 is made of powder coating material,
It covers the outer casings 2 and 3. An epoxy type can be used as the powder coating material 8. The second exterior body 8 is attached by a powder coating method.

As described above, the piezoelectric vibrator 1 is the piezoelectric substrate 1
01 has vibrating electrodes facing each other on both sides thereof, and the vibrating electrodes form a vibrating portion.
1, 31 surround the vibrating portion and are bonded on the surface of the piezoelectric substrate 101, and the sealing films 22, 32 are the spacers 2.
Since the cavities 4 and 5 that are attached to the end faces of 1 and 31 and are formed around the vibrating portion by the spacers 21 and 31 are sealed, the cavities 4 and 5 ensure a vibration space that does not cause vibration disturbance. Parts are obtained.

In the first outer casings 2 and 3, spacers 21 and 31 are made of an adhesive layer and adhered onto the surface of the piezoelectric substrate 101.
Since the sealing films 22 and 32 are attached to the end surfaces of the spacers 21 and 31, the number of parts can be reduced.

Since the second outer casing 8 covers the first outer casings 2 and 3, a double protective structure for protecting the first outer casings 2 and 3 with the second outer casing 8 can be obtained, and the second outer casing 8 can be protected by an external force. Deformation of the cavities 4 and 5 and deterioration of airtightness of the cavities 4 and 5 are less likely to occur, and reliability is improved. Moreover, since the second exterior body 8 is made of powder coating material, a piezoelectric component having excellent moisture resistance can be obtained.

In the case of the embodiment in which the spacers 21 and 31 are composed of the adhesive layer cured from the B stage, the change in the volume of the cavities 4 and 5 due to the crushing and the protrusion of the spacers 21 and 31 is 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 this example, the reinforcement layer 9
1 and 92. The reinforcing layer 91 is arranged between the sealing film 22 and the second outer casing 8, and the reinforcing layer 92 is arranged between the sealing film 32 and the second outer casing 8. The reinforcing layers 91 and 92 can be made of a ceramic thin plate or a metal thin plate. With such a structure, the sealing films 22 and 32 having low mechanical strength are reinforced by the reinforcing layers 91 and 92, and the cavities 4 and 5 are irrespective of the pressure applied when the second exterior body 8 is attached. It is possible to prevent deformation and deterioration of airtightness.

FIG. 4 is a front sectional view showing another embodiment of the piezoelectric component according to the present invention. Spacer 21 is at least 3
It is a laminated body of layers, and adhesive layers 211 and 212 capable of taking the B stage are attached to both sides of the intermediate layer 210. 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 intermediate layers 210 and 310 are preferably made of the same material as the sealing films 22 and 32. Figure 4
In the case of this embodiment, the height of the cavities 4 and 5 can be increased in addition to the effects described with reference to FIGS. 1 and 2.

5 to 10 are views showing a method of manufacturing a piezoelectric component according to the present invention. First, as shown in FIGS. 5 and 6, a 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. 7, the sealing film 22
5 and 6 show the first exterior body 2 having the B-stage spacer adhesive 21 on one surface thereof and the first exterior body 3 having the B-stage spacer adhesive 31 on one surface of the sealing film 32. The piezoelectric substrate 101 shown in FIG. Spacer adhesives 21, 31 are sealing films 22
It is formed by a printing process, for example, so as to have a predetermined pattern on the top. The sealing films 22 and 32 can be made of resin or ceramic. Heat treatment is used for adhesion. As a result, the B-stage adhesives 21 and 31 are remelted and adhere to the surface of the piezoelectric substrate 101. Since the spacer adhesives 21 and 31 are B stage, in this heating step, the spacer adhesives 21 and 31 are
There is almost no crushing or protruding of 31. Therefore, 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. 8 and 9, 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.

Thereafter, the powder coating material is applied by the fluid immersion powder coating method, the electrostatic coating method, or the like to obtain the piezoelectric component according to the present invention. FIG. 10 is a diagram showing a fluidized-bed method. Piezoelectric component A after the process of FIGS. 8 and 9 is completed
While being transported by the carrier B, preheated by the heater C1 at, for example, 150 ° C. for about 2 minutes, then immersed in the fluid powder 80, and the powder coating material is attached around the piezoelectric component A and pulled up. 150 using heater C2
Preheat at ℃ for 2 minutes. After repeating this step about 2 to 3 times, the powder coating is cured by heating at a temperature of 150 ° C. for about 1 to 2 hours. As a result, a completed piezoelectric component according to the present invention is obtained.

In the embodiment, the piezoelectric component having a single vibrating portion and the method for 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.

[0026]

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 the first exterior body has a spacer surrounding the vibrating portion and on the surface of the piezoelectric substrate. Since the sealing film is adhered to the end face of the spacer to seal the cavity formed around the vibrating portion by the spacer, it is possible to provide a piezoelectric component in which a vibration space that does not cause a vibration obstacle is secured. (B) Since the spacer of the first exterior body is made 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, it is possible to provide a piezoelectric component having a small number of parts. (C) Since the second exterior body covers the periphery of the first exterior body, a double protective structure for protecting the first exterior body with the second exterior body can be obtained, and the cavity deformation and the airtightness reduction of the cavity due to the external force can be obtained. Less likely to occur. (D) Since the second exterior body is made of powder coating material, a piezoelectric component having excellent moisture resistance can be obtained. (E) When the spacer is composed of an adhesive layer cured from the B stage, it is possible to provide a piezoelectric component with high reliability and high quality, which requires less variation in the cavity volume due to crushing and protrusion of the spacer. (F) Since the B-stage adhesive is solid at room temperature and 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 cross-sectional view of another embodiment of the piezoelectric component according to the present invention.

FIG. 5 is a plan view of a piezoelectric substrate used in the method of manufacturing a piezoelectric component according to the present invention.

6 is a cross-sectional view taken along the line A6-A6 of FIG.

FIG. 7 is a diagram showing a step of assembling the first exterior body with the piezoelectric substrate shown in FIGS. 5 and 6;

FIG. 8 is a plan view of the assembly after the steps of FIG.

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

FIG. 10 is a diagram illustrating a powder coating method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric vibrator 101 Piezoelectric substrate 102, 103 Electrode 2, 3 1st exterior body 21, 31 Spacer 22, 32 Sealing film 8 2nd exterior body

Claims (5)

[Claims] 1. A piezoelectric component including a piezoelectric vibrator, a first outer package, and a second outer package, wherein the piezoelectric oscillator has vibrating electrodes facing each other on both sides of a piezoelectric substrate, The vibrating electrode constitutes a vibrating portion, the first exterior body has a spacer and a sealing film, and the spacer is made of an adhesive and surrounds the vibrating portion on the surface of the piezoelectric substrate. The sealing film is adhered onto the spacer to seal the cavity formed around the vibrating portion by the spacer, and the second exterior body is made of powder coating material, A piezoelectric component that adheres to and covers the first exterior body. 2. The piezoelectric component according to claim 1, wherein the spacer is composed of an adhesive layer cured from the B stage. 3. The piezoelectric component according to claim 1, further comprising a reinforcing layer, wherein the reinforcing layer is arranged between the sealing film and the second exterior body. 4. The piezoelectric component according to claim 3, wherein the reinforcing layer is made of a ceramic thin plate or a metal thin plate. 5. The method for manufacturing a piezoelectric component according to claim 1, wherein the first step is a step of laminating an outer package having an adhesive on one surface of a sealing film on a piezoelectric substrate and adhering the outer package. The second step is a method of manufacturing a piezoelectric component, which is a step of applying the powder coating material to the whole after the first step.