A piezoelectric ceramic chip integrated structure
By using anisotropic conductive adhesive cold pressing technology and conductive pillars between the piezoelectric ceramic chip and the flexible circuit board, the problem of unstable connection between the piezoelectric ceramic chip and the circuit board was solved, achieving stable signal transmission and improving the reliability of the connection.
Patent Information
- Application Number
- CN202520630402.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2026-11-06
- Estimated Expiration
- 2035-04-03
AI Technical Summary
In existing technologies, the connection between piezoelectric ceramic chips and circuit boards is prone to problems such as poor soldering and false soldering. Furthermore, the long-term reliability and stability of conductive adhesive connections are poor, affecting the stability and reliability of signal transmission.
By employing flexible circuit boards and anisotropic conductive adhesive cold pressing technology, anisotropic conductive adhesive is laid between the ground and functional areas of the piezoelectric ceramic chip and the circuit structure to form a stable conductive connection. Combined with conductive pillars and solder mask layer, a stable connection between the piezoelectric ceramic chip and the flexible circuit board is achieved.
This improves the connection stability between the piezoelectric ceramic chip and the flexible circuit board, avoids signal transmission instability caused by poor soldering and conductive adhesive aging, and enhances the reliability and durability of the connection.
Smart Images
Figure CN224947750U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of integrated circuit technology, specifically to a piezoelectric ceramic chip integrated structure. Background Technology
[0002] The common connection methods between piezoelectric ceramic chips and circuit boards are mainly as follows:
[0003] I. Soldering, one of the most common connection methods. First, apply an appropriate amount of flux to the electrodes of the piezoelectric ceramic chip and the corresponding pads on the circuit board. Then, use a soldering iron to melt the solder wire, allowing the molten solder to fully wet the chip electrodes and the circuit board pads, thus achieving a connection. Soldering is relatively simple and inexpensive, suitable for connecting most common piezoelectric ceramic chips to circuit boards. However, soldering can lead to issues such as cold solder joints or poor soldering. In subsequent use, these poorly soldered areas may experience increased contact resistance, unstable signal transmission, or even disconnection.
[0004] 2. Apply conductive adhesive to the electrodes of the chip and the pads on the circuit board, then press the piezoelectric ceramic chip onto the circuit board, ensuring the conductive adhesive fully fills the gaps between them. After curing, a conductive connection is formed. The advantage of conductive adhesive bonding is that it avoids the impact of high temperatures during the soldering process on the chip, making it suitable for temperature-sensitive piezoelectric ceramic chips. Furthermore, conductive adhesive has a certain degree of flexibility, allowing it to withstand a certain degree of vibration and impact. However, conductive adhesive ages over long-term use, leading to a decrease in conductivity, affecting signal transmission, and its long-term reliability and stability are relatively poor.
[0005] Therefore, it is necessary to study a piezoelectric ceramic chip integrated structure that can stably connect the piezoelectric ceramic chip to the circuit board. Utility Model Content
[0006] One of the objectives of this invention is to provide an integrated structure for a piezoelectric ceramic chip that can improve the connection stability between the piezoelectric ceramic chip and the flexible circuit board.
[0007] To achieve this objective, the present invention adopts the following technical solution:
[0008] On the one hand, this utility model provides a piezoelectric ceramic chip integrated structure, including:
[0009] A flexible circuit board includes a flexible substrate and a circuit structure, wherein the circuit structure is attached to the flexible substrate;
[0010] The piezoelectric ceramic chip and the interface are spaced apart. The interface is electrically connected to the circuit structure through a first conductive part. The ground region and the functional region of the piezoelectric ceramic chip are electrically connected to the circuit structure through a second conductive part formed by cold pressing anisotropic conductive adhesive.
[0011] As a further embodiment of the piezoelectric ceramic chip integration structure, the circuit structure includes a first circuit layer, a second circuit layer, and conductive pillars. The first circuit layer and the second circuit layer are respectively attached to two opposite sides of the flexible substrate along the thickness direction. The interface portion is electrically connected to the first circuit layer through the first conductive portion, and the piezoelectric ceramic chip is electrically connected to the second circuit layer through the second conductive portion. The conductive pillars penetrate the flexible substrate and extend to the first and second sides of the flexible substrate, and the first circuit layer is electrically connected to the second circuit layer through the conductive pillars.
[0012] As a further embodiment of the piezoelectric ceramic chip integration structure, it also includes a first solder mask layer and a second solder mask layer. The first solder mask layer covers the first circuit layer, and the pad area of the first circuit layer is exposed outside the first solder mask layer and electrically connected to the interface portion through the first conductive portion. The second solder mask layer covers the second circuit layer, and the pad area of the second circuit layer is exposed outside the second solder mask layer and electrically connected to the ground area and the functional area through the second conductive portion.
[0013] As a further embodiment of the piezoelectric ceramic chip integration structure, the anisotropic conductive adhesive is ACF or ACP.
[0014] As a further embodiment of the piezoelectric ceramic chip integrated structure, the first conductive part is formed by sintering conductive paste.
[0015] As a further embodiment of the piezoelectric ceramic chip integration structure, the piezoelectric ceramic chip is located at the edge of the flexible substrate.
[0016] As a further embodiment of the piezoelectric ceramic chip integration structure, the flexible substrate is selected from any one of PI, PET, and PP materials.
[0017] The beneficial effects of this invention are as follows: By attaching the circuit structure to a flexible substrate and laying anisotropic conductive adhesive between the ground region of the piezoelectric ceramic chip and the circuit structure, as well as between the functional region and the circuit structure, the anisotropic conductive adhesive is cold-pressed to form a second conductive part. This achieves a stable connection between the ground region, functional region, and circuit structure of the piezoelectric ceramic chip. Furthermore, the piezoelectric ceramic chip and the interface are spaced apart, which does not affect the bending of the area between the piezoelectric ceramic chip and the interface. This invention effectively improves the connection stability between the piezoelectric ceramic chip and the flexible circuit board. Attached Figure Description
[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments of this utility model will be briefly described below. Obviously, the drawings described below are merely some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.
[0019] Figure 1 This is a schematic diagram of the piezoelectric ceramic chip integrated structure described in an embodiment of this utility model. Detailed Implementation
[0020] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.
[0021] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images. They should not be construed as limiting the scope of this patent. To better illustrate the embodiments of this utility model, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.
[0022] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.
[0023] In the description of this utility model, unless otherwise explicitly specified and limited, the term "connection" or similar designation indicating the connection relationship between components should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0024] like Figure 1As shown, the piezoelectric ceramic chip integrated structure of this embodiment includes a flexible circuit board, a piezoelectric ceramic chip 3, and an interface portion 4. The flexible circuit board includes a flexible substrate 1, a circuit structure 2, a piezoelectric ceramic chip 3, and an interface portion 4. The circuit structure 2 is attached to the surface of the flexible substrate 1. The piezoelectric ceramic chip 3 and the interface portion 4 are spaced apart. The interface portion 4 is electrically connected to the circuit structure 2 through a first conductive portion 5. The ground region 31 and the functional region 32 of the piezoelectric ceramic chip 3 are electrically connected to the circuit structure 2 through a second conductive portion 6 formed by cold pressing anisotropic conductive adhesive.
[0025] In this embodiment, the circuit structure 2 is attached to the flexible substrate 1, and anisotropic conductive adhesive is laid between the ground region 31 of the piezoelectric ceramic chip 3 and the circuit structure 2, and between the functional region 32 and the circuit structure 2. The anisotropic conductive adhesive is then cold-pressed to form the second conductive part 6, thereby achieving a stable connection between the ground region 31, the functional region 32 and the circuit structure 2 of the piezoelectric ceramic chip 3. Furthermore, the piezoelectric ceramic chip 3 and the interface part 4 are spaced apart, which does not affect the bending of the area between the piezoelectric ceramic chip 3 and the interface part 4.
[0026] In this embodiment, after the anisotropic conductive adhesive is cold-pressed, conductive particles (such as metal microspheres, carbon nanotubes, etc.) in the material in the direction of pressure form conductive paths. Perpendicular to the direction of pressure, the particles are dispersed and discontinuous, and therefore do not conduct electricity.
[0027] Further, the circuit structure 2 includes a first circuit layer 21, a second circuit layer 22, and a conductive post 23. The first circuit layer 21 and the second circuit layer 22 are respectively attached to two opposite sides of the flexible substrate 1 along the thickness direction. The interface portion 4 is electrically connected to the first circuit layer 21 through the first conductive portion 5, and the piezoelectric ceramic chip 3 is electrically connected to the second circuit layer 22 through the second conductive portion 6. The conductive post 23 penetrates the flexible substrate 1 and extends to the first side and the second side of the flexible substrate 1. The first circuit layer 21 is electrically connected to the second circuit layer 22 through the conductive post 23.
[0028] The first circuit layer 21 includes a first seed layer attached to one side of the flexible substrate 1 and a first rewiring layer attached to the first seed layer. The second circuit layer 22 includes a second seed layer attached to the other side of the flexible substrate 1 and a second rewiring layer attached to the second seed layer. The stability of the first rewiring layer and the second rewiring layer on the flexible substrate 1 can be improved through the first seed layer and the second seed layer.
[0029] Furthermore, the piezoelectric ceramic chip integrated structure also includes a first solder resist layer 7 and a second solder resist layer 8. The first solder resist layer 7 covers the first circuit layer 21, and the pad area of the first circuit layer 21 is exposed on the first solder resist layer 7 and electrically connected to the interface portion 4 through the first conductive portion 5. The second solder resist layer 8 covers the second circuit layer 22, and the pad area of the second circuit layer 22 is exposed on the second solder resist layer 8 and electrically connected to the ground area 31 and the functional area 32 through the second conductive portion 6. By setting the first solder resist layer 7 and the second solder resist layer 8, the non-pad areas of the first circuit layer 21 and the non-pad areas of the second circuit layer 22 are protected.
[0030] Further, the anisotropic conductive adhesive is ACF (Anisotropic Conductive Film) or ACP (Anisotropic Conductive Paste). In other embodiments, the anisotropic conductive adhesive is also selected from silver-coated copper paste and precious metal conductive particle paste, wherein the precious metal conductive particle paste is selected from precious metal gold conductive particle paste and / or precious metal platinum conductive particle paste.
[0031] Furthermore, the first conductive part 5 is sintered from conductive paste, which can also improve the connection stability between the interface part 4 and the first circuit layer 7, while ensuring that the conductivity between the two is not affected.
[0032] Furthermore, the piezoelectric ceramic chip 3 is located at the edge of the flexible substrate 1, which facilitates the connection between the piezoelectric ceramic chip 3 and the first circuit layer 21.
[0033] In this embodiment, the flexible substrate 1 is selected from any one of PI (Polyimide), PET (Polyethylene terephthalate), and PP (Polypropylene). The circuit structure 2 is attached to the flexible substrate 1 and can be bent and deformed with the flexible substrate 1.
[0034] This embodiment also provides a method for fabricating the piezoelectric ceramic chip integrated structure, including the following steps:
[0035] S10. Provide a flexible substrate 1, and fabricate a circuit structure 2 on the flexible substrate 1;
[0036] S20. Provide a piezoelectric ceramic chip 3 and a matching interface 4, bond the interface 4 to the circuit structure 2, and achieve electrical connection between the ground region 31 and the functional region 32 of the piezoelectric ceramic chip 3 and the circuit structure 2 by cold pressing with anisotropic conductive adhesive, and make the piezoelectric ceramic chip 3 and the interface 4 spaced apart.
[0037] Specifically, anisotropic conductive adhesive is laid on the pad areas at the edges of the first circuit layer 21. Then, the ground area 31 and the functional area 32 are aligned and bonded to their corresponding pad areas. The second conductive part 6 is formed by cold pressing, thereby achieving a stable connection between the ground area 31 and the functional area 32 and their corresponding pad areas. The method of this embodiment can achieve automated and rapid mass production, effectively improving product manufacturing efficiency.
[0038] Furthermore, the temperature for cold pressing bonding is 25-80℃, and the pressure is 0.5-10MPa.
[0039] Furthermore, the specific steps of step S10 are as follows:
[0040] S11. Provide a temporary carrier board and create a graphical first circuit layer 21 on the temporary carrier board;
[0041] S12. Fabricate a flexible substrate 1 on the first circuit layer and make the flexible substrate 1 completely cover the first circuit layer 21.
[0042] S13. The flexible substrate 1 is perforated to form a hole structure that exposes part of the first circuit layer 21.
[0043] S14. Conductive pillars 23 are fabricated within the hole structure and a second circuit layer 22 is fabricated on the flexible substrate 1.
[0044] S15. Remove the temporary carrier board, brush green ink on the first circuit layer 21, and after curing, form the first solder mask layer 7. Brush green ink on the second circuit layer 22, and after curing, form the second solder mask layer 8. The first circuit layer 21, the second circuit layer 22, and the conductive pillar 23 constitute the circuit structure 2.
[0045] Among them, the first seed layer and the first redistribution layer included in the first circuit layer 21 and the second seed layer and the second redistribution layer included in the second circuit layer 22 are prepared by conventional vacuum sputtering method, and the first redistribution layer and the second redistribution layer are prepared by conventional electroplating method. These are all conventional technical means in the field, and will not be described in detail.
[0046] Of course, the method for preparing the circuit structure 2 in this embodiment is not limited to this. For example, a flexible substrate 1 is provided, a through hole is made in the flexible substrate 1, and then a conductive pillar 23 is made in the through hole and a first circuit layer 21 and a second circuit layer 22 are made on the surface of the flexible substrate 1 respectively. Then, the first solder resist layer 7 and the second solder resist layer 8 can be prepared according to the method of the above embodiment. The specific details will not be repeated.
[0047] It should be stated that the above-described specific embodiments are merely preferred embodiments of this utility model and the technical principles employed. Those skilled in the art should understand that various modifications, equivalent substitutions, and variations can be made to this utility model. However, such variations, as long as they do not depart from the spirit of this utility model, should be within the protection scope of this utility model. Furthermore, some terminology used in this application specification and claims is not limiting, but merely for ease of description.
Claims
1. A piezoelectric ceramic chip integrated structure, characterized in that, include: A flexible circuit board includes a flexible substrate and a circuit structure, wherein the circuit structure is attached to the flexible substrate; The piezoelectric ceramic chip and the interface are spaced apart. The interface is electrically connected to the circuit structure through a first conductive part. The ground region and the functional region of the piezoelectric ceramic chip are electrically connected to the circuit structure through a second conductive part formed by cold pressing anisotropic conductive adhesive.
2. The piezoelectric ceramic chip integrated structure according to claim 1, characterized in that, The circuit structure includes a first circuit layer, a second circuit layer, and conductive pillars. The first circuit layer and the second circuit layer are respectively attached to two opposite sides of the flexible substrate along the thickness direction. The interface portion is electrically connected to the first circuit layer through the first conductive portion, and the piezoelectric ceramic chip is electrically connected to the second circuit layer through the second conductive portion. The conductive pillars penetrate the flexible substrate and extend to the two opposite sides of the flexible substrate along the thickness direction. The first circuit layer is electrically connected to the second circuit layer through the conductive pillars.
3. The piezoelectric ceramic chip integrated structure according to claim 2, characterized in that, It also includes a first solder mask layer and a second solder mask layer. The first solder mask layer covers the first circuit layer, and the pad area of the first circuit layer is exposed outside the first solder mask layer and electrically connected to the interface portion through the first conductive part. The second solder mask layer covers the second circuit layer, and the pad area of the second circuit layer is exposed outside the second solder mask layer and electrically connected to the ground area and the functional area through the second conductive part.
4. The piezoelectric ceramic chip integrated structure according to claim 1, characterized in that, The anisotropic conductive adhesive is selected from ACF or ACP.
5. The piezoelectric ceramic chip integrated structure according to claim 1, characterized in that, The first conductive part is formed by sintering conductive paste.
6. The piezoelectric ceramic chip integrated structure according to any one of claims 1 to 5, characterized in that, The piezoelectric ceramic chip is located at the edge of the flexible substrate.
7. The piezoelectric ceramic chip integrated structure according to any one of claims 1 to 5, characterized in that, The flexible substrate is selected from any one of PI, PET, and PP materials.