Composite electrode suitable for piezoelectric device

Abstract

The composite electrode comprises a high-strength insulating substrate, metal electrode layers are attached to the upper surface and the lower surface of the high-strength insulating substrate respectively, the metal electrode layers and the high-strength insulating substrate are integrally formed, and the edges of the metal electrode layers are at least reduced by 0.5 mm compared with the edges of the corresponding high-strength insulating substrate. A circle of insulation protection layer is formed around the metal electrode layer. The metal electrode and the high-strength insulating substrate are integrally formed, the insulating substrate has excellent flexibility and structural strength, the defect that the structural strength of an electrode layer is insufficient is overcome, and the problem that the electrode is prone to being broken in the welding and assembling process is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of transducers and relates to a composite electrode suitable for a piezoelectric device. Background Art

[0002] As an energy conversion device, one of the key processes of the transducer is how to reliably connect the piezoelectric element to the external wire or circuit. The commonly used solution is to directly weld or bond the wire on the surface of the piezoelectric element to transmit the signal. This solution is only applicable to single-layer piezoelectric elements, and there are problems such as high temperature during welding that damages the performance of the piezoelectric element and poor bonding reliability, and the applicable scenarios are highly limited; another solution is to bond a single-layer metal electrode such as copper foil with pins to the surface of the piezoelectric element, and use the pins of the metal electrode to weld the wire to transmit the signal. It can be applied between multi-layer piezoelectric elements and also reduces the damage of the piezoelectric element to the high temperature of welding. However, due to the low mechanical strength of metal electrodes such as copper foil, it is easy to break or tear the electrode pins when pressed by the test instrument probe and pulled by the wire in the subsequent testing, welding, and assembly process links, and the reliability is poor; at the same time, the electrode edge is exposed on the outside of the transducer vibrator. For thin components such as piezoelectric polymer film, the distance between the multi-layer electrodes can be as low as a few hundred microns. Positioning deviations when bonding electrodes to piezoelectric devices, bending of electrode pins, and excessive soldering of pins can all lead to contact short circuits between multi-layer electrodes. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a composite electrode suitable for piezoelectric devices, in which a metal electrode and a high-strength insulating substrate are integrated into one body. The insulating substrate has excellent flexibility and structural strength, which makes up for the disadvantage of insufficient structural strength of the electrode layer and solves the problem that the electrode is easily broken during welding and assembly.

[0004] The technical solution of the present invention is to provide a composite electrode suitable for piezoelectric devices, including a high-strength insulating substrate, wherein metal electrode layers are respectively adhered to the upper and lower surfaces of the high-strength insulating substrate, and the metal electrode layer and the high-strength insulating substrate are integrally formed. The edge of the metal electrode layer is retreated by at least 0.5 mm compared to the corresponding edge of the high-strength insulating substrate, so as to form a circle of insulating protection layer around the metal electrode layer.

[0005] Preferably, the metal electrode layer is made of a conductive material, and the conductive material includes at least one of rolled copper, electrolytic copper, aluminum, gold, graphene, carbon nanotubes, and conductive silver paste.

[0006] Preferably, the high-strength insulating substrate includes any one of polyimide and polyester.

[0007] Preferably, the one-piece molding process is a sputtering process or a screen printing process.

[0008] Preferably, the metal electrode layer and the high-strength insulating substrate can be formed by bonding to replace the one-piece molding process.

[0009] Preferably, the adhesive material is any one of epoxy resin and acrylic adhesive.

[0010] Preferably, the metal electrode layers on the upper and lower surfaces of the high-strength insulating substrate are completely the same in size and shape.

[0011] Compared with the prior art, the present invention has the following advantages: The present invention proposes a composite electrode suitable for piezoelectric devices, in which a high-strength insulating substrate with good flexibility and mechanical strength is added to two layers of metal electrodes, thereby improving the mechanical properties of the electrodes and making the electrodes less susceptible to damage when bent or pulled; at the same time, the area of ​​the insulating substrate is slightly larger than the metal electrode layer, and a circle of insulating protection layer can be formed around the metal electrode layer, reducing the risk of accidental short circuit between the multi-layer electrodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the structure of the present invention.

[0013] Figure 2 It is a schematic diagram of the composite electrode structure of the present invention.

[0014] Figure 3 The figure is a schematic diagram of a usage scenario of an embodiment of the present invention.

[0015] Figure 4 The figure is a schematic diagram of the usage scenario composition of an embodiment of the present invention. DETAILED DESCRIPTION

[0016] The present invention will be further described below with reference to the accompanying drawings: A composite electrode suitable for use in piezoelectric devices, such as Figure 1-2 As shown, the composite electrode 1 includes a high-strength insulating substrate 3, and the metal electrode layer 2 is attached to the upper and lower surfaces of the high-strength insulating substrate 3, respectively. The edge of the metal electrode layer 2 is retreated by 0.6 mm compared with the corresponding edge of the high-strength insulating substrate 3, so as to form a circle of insulating protection layer around the metal electrode layer 2. In other words, the area of ​​the high-strength insulating substrate 3 is slightly larger than the area of ​​the metal electrode layer 2, and a circle of insulating protection layer can be formed around the metal electrode layer 2 to prevent the problem of accidental short circuit between the multi-layer electrodes.

[0017] In this embodiment, the metal electrode layers 2 on the upper and lower surfaces of the high-strength insulating substrate 3 are completely the same in size and shape, and the metal electrode layer and the high-strength insulating substrate are integrally formed, and the specific process is a sputtering process.

[0018] In this embodiment, the metal electrode layer 2 is made of rolled copper material, which has strong ductility and bending resistance. The high-strength insulating substrate 3 is made of PI material, which has excellent structural strength, insulation performance, flexibility, and high temperature resistance.

[0019] As an alternative, the metal electrode layer 2 and the high-strength insulating substrate 3 may also be bonded together using an acrylic adhesive.

[0020] As a preferred embodiment, both the high-strength insulating substrate 3 and the metal electrode layer 2 have a pin structure for welding leads.

[0021] like Figure 3-4 , showing the application scenario of bonding the composite electrode 1 and the piezoelectric device 4 in this embodiment. The composite electrode 1 and the multilayer piezoelectric device 4 are alternately placed and bonded. Since the composite electrode 1 has an edge insulation layer, it can be ensured that there is no exposed electrode on the side of the transducer vibrator after bonding except for the pins. Positioning deviation during bonding, bending of electrode pins, excessive soldering of pins, etc. will not cause short circuit problems between multilayer electrodes, thereby improving the insulation performance between multilayer electrodes.

[0022] It can be seen that the composite electrode proposed in the present invention adds a high-strength insulating substrate with good flexibility and mechanical strength between the two layers of metal electrodes, which improves the mechanical properties of the electrodes and makes the electrodes less likely to be damaged when bent or pulled; at the same time, the area of ​​the high-strength insulating substrate is slightly larger than the metal electrode layer, and a circle of insulating protection layer can be formed around the metal electrode layer, reducing the risk of accidental short circuit between the multi-layer electrodes.

[0023] The above is only an explanation of the preferred embodiments of the present invention, which should not be construed as a limitation on the claims. Any equivalent process changes made using the present invention specification are included in the patent protection scope of the present invention.

Claims

1. A composite electrode suitable for a piezoelectric device, characterized in that: It includes a high-strength insulating substrate, with metal electrode layers attached to the upper and lower surfaces of the high-strength insulating substrate respectively. The metal electrode layer and the high-strength insulating substrate are integrally formed, and the edge of the metal electrode layer is retreated by at least 0.5mm compared to the corresponding edge of the high-strength insulating substrate, so as to form a circle of insulating protection layer around the metal electrode layer.

2. The composite electrode for piezoelectric devices according to claim 1, characterized in that: The metal electrode layer is made of conductive material, and the conductive material includes at least one of rolled copper, electrolytic copper, aluminum, gold, graphene, carbon nanotubes, and conductive silver paste.

3. The composite electrode for piezoelectric devices according to claim 1, characterized in that: The high-strength insulating substrate includes any one of polyimide and polyester.

4. The composite electrode for piezoelectric devices according to claim 1, characterized in that: The one-piece molding process is a sputtering process or a screen printing process.

5. The composite electrode for piezoelectric devices according to claim 1, characterized in that: The metal electrode layer and the high-strength insulating substrate can be formed by bonding to replace the one-piece molding process.

6. The composite electrode for piezoelectric devices according to claim 5, characterized in that: The adhesive material is any one of epoxy resin and acrylic adhesive.

7. The composite electrode for piezoelectric devices according to claim 1, characterized in that: Both the high-strength insulating substrate and the metal electrode layer have a pin structure for welding leads.

8. The composite electrode for piezoelectric devices according to claim 1, characterized in that: The metal electrode layers on the upper and lower surfaces of the high-strength insulating substrate are completely the same in size and shape.

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