CN109599483B

CN109599483B - Piezoelectric ceramic device and method for forming the same

Info

Publication number: CN109599483B
Application number: CN201811478469.0A
Authority: CN
Inventors: 李韦坤
Original assignee: Interface Optoelectronics Shenzhen Co Ltd; Interface Technology Chengdu Co Ltd; General Interface Solution Ltd
Current assignee: Interface Optoelectronics Shenzhen Co Ltd; Interface Technology Chengdu Co Ltd; General Interface Solution Ltd
Priority date: 2018-12-05
Filing date: 2018-12-05
Publication date: 2022-07-08
Anticipated expiration: 2038-12-05
Also published as: TWI689114B; TW202023077A; CN109599483A

Abstract

A piezoelectric ceramic device comprises an upper electrode layer, a lower electrode layer, a piezoelectric ceramic material layer, a three-proofing adhesive layer and a pressure-sensing adhesive layer. The piezoelectric ceramic material layer is clamped between the upper electrode layer and the lower electrode layer. The three-proofing glue layer is arranged on the left side and the right side of the piezoelectric ceramic material layer. The pressure-sensitive adhesive layer covers the upper electrode layer and the three-proofing adhesive layer.

Description

Piezoelectric ceramic device and method for forming the same

Technical Field

Embodiments of the present disclosure relate to a piezoelectric ceramic device, and more particularly, to a piezoelectric ceramic device and a method for forming the same.

Background

The piezoelectric material has a piezoelectric effect of changing electrode polarization by receiving stress from the outside and an inverse piezoelectric effect of generating distortion by applying an electric field, and is widely used in piezoelectric ceramic devices such as piezoelectric vibrators, piezoelectric filters, piezoelectric actuators, piezoelectric transformers, and piezoelectric buzzers.

Disclosure of Invention

The present disclosure provides a piezoelectric ceramic device including an upper electrode layer, a lower electrode layer, a piezoelectric ceramic material layer, a Conformal Coating (CC) layer, and a Pressure Sensitive Adhesive (PSA) layer. The piezoelectric ceramic material layer is clamped between the upper electrode layer and the lower electrode layer. The three-proofing glue layer is arranged on the left side and the right side of the piezoelectric ceramic material layer. The pressure-sensitive adhesive layer covers the upper electrode layer and the three-proofing adhesive layer.

In some embodiments, the piezoelectric ceramic device further includes a Flexible Printed Circuit (FPC), and the bottom electrode layer is bonded to the FPC through a Conductive Adhesive (Conductive Adhesive).

In some embodiments, the three-proofing adhesive layer is disposed on the flexible printed circuit board, and the pressure-sensitive adhesive layer covers the flexible printed circuit board.

In some embodiments, the Young's Modulus (Young's Modulus) of the three-proofing layer is greater than 1 gigapascal (1 GPa).

In some embodiments, the Cross Section (Cross Section) of the three-proof adhesive layer is triangular, so that the turning angles of the pressure-sensitive adhesive layer are all larger than 100 degrees.

The present disclosure further provides a method for forming a piezoelectric ceramic device, comprising: providing a piezoelectric ceramic material layer which is clamped between an upper electrode layer and a lower electrode layer; carrying out a dispensing (Dispense) process to enable the three-proofing adhesive layer to be arranged on the left side and the right side of the piezoelectric ceramic material layer; and performing an encapsulation process to cover the pressure-sensitive adhesive layer with the upper electrode layer and the three-proofing adhesive layer.

In some embodiments, the method for forming a piezoelectric ceramic device further includes: before the dispensing process, an Anisotropic Conductive Adhesive (ACA) is distributed on the flexible printed circuit board by a spraying process; and performing a Bonding process to bond the lower electrode layer to the FPC via the anisotropic conductive adhesive.

In some embodiments, the Young's modulus of the three-proofing adhesive layer is greater than 1 GPa.

In some embodiments, the three-proofing adhesive layer has a triangular cross section, so that the turning angles of the pressure-sensitive adhesive layer are all larger than 100 degrees.

In order to make the aforementioned and other features and advantages of the disclosure more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

Aspects of the present disclosure may be better understood from the following detailed description taken in conjunction with the accompanying drawings. It is noted that, in accordance with standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1 is a cross-sectional view of a piezoelectric ceramic device according to a first embodiment of the present disclosure.

FIGS. 2A to 2B are schematic views illustrating a molding process of a piezoelectric ceramic device according to a first embodiment of the present disclosure.

FIG. 3 is a cross-sectional view of a piezoelectric ceramic device after encapsulation according to a first embodiment of the present disclosure.

FIG. 4 is a cross-sectional view of a piezoelectric ceramic device according to a second embodiment of the present disclosure.

FIG. 5 is a schematic diagram of a second embodiment of the present disclosure.

FIG. 6 is a cross-sectional view of a piezoelectric ceramic device after encapsulation according to a second embodiment of the present disclosure.

Reference numerals:

100. 400: piezoelectric ceramic device 300, 600: piezoelectric ceramic device after encapsulation

110: upper electrode layer 120: lower electrode layer

130: piezoelectric ceramic material layer 140: flexible printed circuit board

142. 144, and (3) 144: contact pad 150: conductive adhesive

160: the pressure sensitive adhesive layer 170: three-proofing adhesive layer

210: vacuum pump 220: upper working table

230: soft rubber 240: lower working table

250: the heating system 260: sealing film

Detailed Description

Embodiments of the invention are discussed in detail below. It should be appreciated, however, that the embodiments provide many applicable concepts that can be embodied in a wide variety of specific contexts. The embodiments discussed and disclosed are merely illustrative and are not intended to limit the scope of the invention.

Fig. 1 is a cross-sectional view of a piezoelectric ceramic device 100 according to a first embodiment of the present disclosure. The piezoelectric ceramic device 100 includes an upper electrode layer 110, a lower electrode layer 120, a piezoelectric ceramic material layer 130, and a Flexible Printed Circuit (FPC) 140. The piezoelectric ceramic material layer 130 is sandwiched between the upper electrode layer 110 and the lower electrode layer 120. The flexible printed circuit board 140 has

contact pads

142 and 144 respectively connected to the upper electrode layer 110 and the lower electrode layer 120 via Conductive Adhesive (Conductive Adhesive) 150.

The method of forming the piezoelectric ceramic device 100 includes: providing a piezoelectric ceramic material layer 130 sandwiched between the upper electrode layer 110 and the lower electrode layer 120; the liquid conductive adhesive 150 is uniformly distributed on the flexible printed circuit board 140 by a spraying process; and performing a Bonding process to bond the upper electrode layer 110 and the lower electrode layer 120 to the

contact pads

142 and 144 of the flexible printed circuit board 140 through the cured conductive paste 150, respectively. In the above-mentioned forming method, the Conductive paste 150 may be an Anisotropic Conductive Adhesive (ACA), but the disclosure is not limited thereto. The bonding process includes pressure bonding and thermal curing (thermal curing), wherein a pressure parameter of the pressure bonding is 0.23 MPa, a temperature parameter of the thermal curing is 120 ℃ and a time parameter of the pressure bonding and the thermal curing is 170 seconds, but the disclosure is not limited thereto.

When the piezoceramic material layer 130 is under pressure, a voltage difference occurs between the upper and lower surfaces thereof, and at this time, the flexible printed circuit board 140 obtains the voltage values of the upper electrode layer 110 and the lower electrode layer 120 through the

contact pads

142 and 144, respectively, so that the voltage difference can be converted into mechanical energy, such as vibration force or lower pressure force, etc., which is applied to the piezoceramic material layer 130.

Since the upper electrode layer 110, the lower electrode layer 120, and/or the conductive paste 150 of the piezoelectric ceramic device 100 are still partially exposed, encapsulation (Encapsulating) is usually performed on the piezoelectric ceramic device 100 to better protect the piezoelectric ceramic device 100. Fig. 2A to 2B are schematic views illustrating a molding process of a piezoelectric ceramic device 100 according to a first embodiment of the disclosure. Referring to fig. 2A, the molding machine includes a vacuum pump 210, an upper table 220, a soft rubber (rubber) 230, a lower table 240, and a heating system 250. The piezoelectric ceramic device 100 is disposed on the lower platen 240, and the vacuum pump 210 is used to make the vacuum degree in the cavity of the molding machine smaller than 0.2 torr. An Encapsulation Film (Encapsulation Film)260 is disposed on the lower surface of the soft rubber 230. Please refer to fig. 2B, which is a schematic diagram of lamination, wherein the lamination is performed with a pressing pressure parameter of 0.5MPa and a pressing time parameter of 2 minutes.

FIG. 3 is a cross-sectional view of a piezoelectric ceramic device 300 after encapsulation according to a first embodiment of the present disclosure. The encapsulated piezoelectric ceramic device 300 further includes a Pressure Sensitive Adhesive (PSA) layer 160, wherein the Pressure Sensitive Adhesive layer 160 covers the upper electrode layer 110 and the flexible printed circuit board 140. Referring to fig. 2B and 3, during the molding process, the soft rubber 230 cannot be completely adhered to the left and right sides of the piezoelectric ceramic device 100 due to the step height of each component in the piezoelectric ceramic device 100, so that bubbles 310 are generated on the left and right sides of the piezoelectric ceramic material layer 130 in the molded piezoelectric ceramic device 300. The bubbles 310 have an adverse effect on the encapsulated piezoelectric ceramic device 300, for example, vibration energy of the encapsulated piezoelectric ceramic device 300 is reduced due to the bubbles 310. Accordingly, the present disclosure provides a second embodiment to improve the above-mentioned drawbacks.

FIG. 4 is a cross-sectional view of a piezoelectric ceramic device 400 in accordance with a second embodiment of the present disclosure. The piezoelectric ceramic device 400 includes an upper electrode layer 110, a lower electrode layer 120, a piezoelectric ceramic material layer 130, a flexible printed circuit board 140, and a Conformal Coating (CC) layer 170. The piezoelectric ceramic material layer 130 is sandwiched between the upper electrode layer 110 and the lower electrode layer 120. The flexible printed circuit board 140 has

contact pads

142 and 144 respectively connected to the upper electrode layer 110 and the lower electrode layer 120 through conductive adhesive 150. The three-proofing adhesive layer 170 is disposed on the left and right sides of the piezoelectric ceramic material layer 130, and the three-proofing adhesive layer 170 is disposed on the flexible printed circuit board 140.

The method of forming the piezoelectric ceramic device 400 includes: providing a piezoelectric ceramic material layer 130 sandwiched between the upper electrode layer 110 and the lower electrode layer 120; a spraying (Spray) process is performed to uniformly distribute the liquid conductive adhesive 150 on the flexible printed circuit board 140; performing a Bonding process to bond the upper electrode layer 110 and the lower electrode layer 120 to the

contact pads

142 and 144 of the flexible printed circuit board 140 through the cured conductive adhesive 150; and performing a dispensing (Dispense) process to dispose the three-proof adhesive layer 170 on the left and right sides of the piezoelectric ceramic material layer 130, wherein the three-proof adhesive layer 170 is disposed on the fpc 140.

In the second embodiment of the present disclosure, the Young's Modulus (Young's Modulus) of the conformal layer 170 is greater than 1 gigapascal (1GPa), but the present disclosure is not limited thereto. As shown in fig. 4, in the second embodiment of the disclosure, the shape of the three-proofing adhesive layer 170 in the cross-sectional direction is a triangle.

FIG. 5 is a diagram illustrating a second embodiment of a piezoelectric ceramic device 400 according to the present disclosure. Fig. 5 is a schematic view of the lamination process, and fig. 5 is similar to fig. 2A and 2B, and therefore, the description of the similarity will not be repeated. FIG. 6 is a cross-sectional view of a piezoelectric ceramic device 600 after encapsulation, in accordance with a second embodiment of the present disclosure. The encapsulated piezoelectric ceramic device 600 further comprises a pressure sensitive adhesive layer 160, wherein the pressure sensitive adhesive layer 160 covers the upper electrode layer 110, the three-proofing adhesive layer 170 and the flexible printed circuit board 140. Referring to fig. 5 and 6, during the molding process, since the three-proof adhesive layer 170 is disposed on the left and right sides of the piezoelectric ceramic material layer 130 by the dispensing process of the piezoelectric ceramic device 400, and the three-proof adhesive layer 170 is triangular in cross-sectional shape, the soft rubber 230 can be completely attached to the left and right sides of the piezoelectric ceramic device 400, so that the piezoelectric ceramic device 600 after the molding process has no bubbles, and the adverse effect of the piezoelectric ceramic device 300 after the molding process due to the bubbles 310 can be improved.

It should be noted that, in the second embodiment of the present disclosure, the triangular shape of the three-proofing adhesive layer 170 of the piezoelectric ceramic device 400 in the cross-sectional direction should not be too steep, so that the soft rubber 230 can be completely attached to the left and right sides of the piezoelectric ceramic device 400 during the molding process. Specifically, the cross section of the three-proofing adhesive layer 170 is triangular, so that the turning angle of the pressure-sensitive adhesive layer 160 of the encapsulated piezoelectric ceramic device 600 is greater than 100 degrees.

In summary, the present disclosure provides a piezoelectric ceramic device and a method for forming the same, wherein a three-proof adhesive layer is disposed on the left and right sides of a piezoelectric ceramic material layer by a dispensing process, so that bubbles are not generated in the piezoelectric ceramic device after encapsulation, and vibration energy of the piezoelectric ceramic device after encapsulation is not reduced due to the generation of bubbles.

The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. It should also be understood by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.

Claims

1. A piezoelectric ceramic device, comprising:

an upper electrode layer;

a lower electrode layer;

a piezoelectric ceramic material layer sandwiched between the upper electrode layer and the lower electrode layer;

the three-proofing adhesive layer is arranged on the left side and the right side of the piezoelectric ceramic material layer, and the shape of the three-proofing adhesive layer in the section direction is triangular; and

a pressure sensitive adhesive layer covering the upper electrode layer and the three-proofing adhesive layer.

2. The piezoelectric ceramic device according to claim 1, further comprising:

a flexible printed circuit board;

wherein, the lower electrode layer is jointed to the flexible printed circuit board through a conductive adhesive.

3. The device of claim 2, wherein the three-proofing adhesive layer is disposed on the FPC, and the pressure-sensitive adhesive layer covers the FPC.

4. The piezoelectric ceramic device according to claim 1, wherein the Young's modulus of the three-proofing adhesive layer is greater than 1 GPa.

5. The piezoelectric ceramic device according to claim 1, wherein the three-proofing adhesive layer has a triangular cross section, such that a plurality of turning angles of the pressure-sensitive adhesive layer are all greater than 100 degrees.

6. A method of forming a piezoelectric ceramic device, comprising:

providing a piezoelectric ceramic material layer clamped between an upper electrode layer and a lower electrode layer;

performing a dispensing process to enable a three-prevention adhesive layer to be arranged on the left side and the right side of the piezoelectric ceramic material layer, wherein the three-prevention adhesive layer is triangular in shape in the section direction; and

a molding process is performed to cover the top electrode layer and the three-proofing adhesive layer with a pressure sensitive adhesive layer.

7. The method of claim 6, further comprising:

before the dispensing process, an anisotropic conductive adhesive is distributed on a flexible printed circuit board through a spraying process; and

a bonding process is performed to bond the lower electrode layer to the FPC through the anisotropic conductive film.

8. The method of claim 7, wherein the conformal adhesive layer is disposed on the FPC, and wherein the pressure sensitive adhesive layer covers the FPC.

9. The method according to claim 6, wherein the Young's modulus of the three-proofing adhesive layer is greater than 1 GPa.

10. The method according to claim 6, wherein the cross-section of the three-proofing adhesive layer is triangular, such that a plurality of turning angles of the pressure-sensitive adhesive layer are all greater than 100 degrees.