Flexible solderable circuit, electronic device and electronic equipment

Abstract

The utility model discloses a flexible solderable circuit, electronic device and electronic equipment wherein the flexible solderable circuit comprises a flexible substrate, a circuit layer and a bonding pad layer which are arranged in sequence, the flexible solderable circuit comprises a temperature-resistant layer formed on the circuit layer, a welding layer is formed on the temperature-resistant layer, the temperature-resistant layer is a patterned layer structure obtained by conducting silver paste through silk-screen printing, and the bonding pad layer is arranged on the flexible substrate. And the welding layer is at least one of the following layer structures deposited on the temperature-resistant layer: copper or an alloy plating layer thereof, tin or an alloy plating layer thereof, gold or an alloy plating layer thereof, and a protective layer. The device is simple in structure, efficient in preparation, environment-friendly and low in application cost.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of printed circuit, and particularly relates to a flexible solderable circuit, device and equipment. BACKGROUND

[0002] In the development process of modern electronic products gradually to high density, miniaturization, light weight, flexible circuit board plays a vital role. The traditional flexible circuit board (FPC, Flexible Printed Circuit) is made of polyimide (PI) base material, which is a kind of free bending, winding, folding and highly reliable printed circuit board. Its preparation process mainly includes copper, exposure, development, etching, film stripping and other steps, and the process is complex and a large amount of copper and other heavy metal waste liquid will be produced in the preparation process, which is not conducive to environmental protection. Due to the relatively complex process flow of traditional flexible circuit board, the material cost and processing cost are high, resulting in high overall cost.

[0003] Therefore, in view of the above technical problems, it is necessary to provide a flexible solderable circuit, device and equipment.

[0004] The information disclosed in this background section is intended only to increase an understanding of the general background of the application, and should not be construed as admitting that the information constitutes prior art that is already known to those of ordinary skill in the art. SUMMARY

[0005] The utility model aims at providing a flexible solderable circuit, device and equipment.

[0006] In order to realize the above-mentioned purpose, the technical scheme provided by a specific embodiment of the utility model is as follows:

[0007] The flexible solderable circuit comprises sequentially arranged

[0008] Flexible substrate,

[0009] Circuit layer,

[0010] Pad layer, which comprises a temperature-resistant layer formed on the circuit layer, and a soldering layer formed on the temperature-resistant layer, the temperature-resistant layer is a patterned layer structure obtained by screen printing of conductive silver paste, the soldering layer is at least any one of the following layer structures deposited on the temperature-resistant layer: copper or its alloy plating layer, tin or its alloy plating layer, gold or its alloy plating layer, and

[0011] Protective layer.

[0012] In one or more embodiments of the utility model, the flexible substrate is a PES layer or a LCP layer or a PI layer.

[0013] In one or more embodiments of the present application, the protective layer is an insulating ink layer or a hot-pressed film material layer.

[0014] In one or more embodiments of the present application, the protective layer is formed with a window structure penetrating through the protective layer, and the window structure is arranged corresponding to the pad layer to expose the welding sites of the components and devices.

[0015] In one or more embodiments of the present application, the window structure is a whole window corresponding to the whole circuit area or a unit window arranged one by one corresponding to each welding site.

[0016] In one or more embodiments of the present application, the electronic device comprises the flexible solderable circuit and the components and devices electrically connected thereto.

[0017] In one or more embodiments of the present application, the electronic device comprises the electronic device.

[0018] Compared with the prior art, the flexible solderable circuit, device and equipment of the present application adopt the process technology of screen printing to pattern the circuit layer and the temperature-resistant layer on the flexible substrate, and form the welding layer on the temperature-resistant layer through the metal surface modification technology such as chemical plating or electroplating, and finally form the protective layer on the circuit layer through the process of screen printing or hot pressing, expose the pad layer of the solderable electronic components and devices, and finally form a flexible solderable circuit. The flexible solderable circuit provided by the present application has simple and efficient preparation process, is green and environmentally friendly, and has low cost compared with the traditional flexible circuit board. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiment or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments described in the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0020] Figure 1 FIG. 1 is a structural schematic diagram of a flexible solderable circuit in an embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to make the technical scheme in the present application better understood by those skilled in the art, the technical scheme in the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0022] The flexible solderable circuit of the present application can sequentially include a flexible substrate, a circuit layer, a pad layer and a protective layer.

[0023] Preferably, the pad layer further includes a temperature-resistant layer and a soldering layer.

[0024] Preferably, the circuit layer and the temperature-resistant layer can be layer structures sequentially deposited on the flexible substrate by a silk screen printing process.

[0025] Preferably, the flexible substrate can be a film material prepared by using PES, LCP or PI high-temperature-resistant engineering plastic as raw material.

[0026] Preferably, the circuit layer can be a conductive functional material prepared by using polyester, polyurethane or epoxy resin high-molecular resin.

[0027] Preferably, the temperature-resistant layer can be a conductive functional material prepared by using polyimide PI, cyanate resin, organic silicon resin, phenolic resin and other high-temperature-resistant high-molecular resin.

[0028] Preferably, the soldering layer can be a solderable plating layer such as copper plating layer, tin plating layer or gold plating layer deposited on the temperature-resistant layer by using metal surface modification technology.

[0029] Preferably, the soldering layer can be formed on the temperature-resistant layer by using chemical plating or electroplating process.

[0030] Preferably, the protective layer can be formed on the circuit layer by using insulating ink printing or film material hot pressing method.

[0031] Preferably, the protective layer needs to be windowed at the pad layer to form a window structure penetrating through, so that the components can be soldered at the pad layer.

[0032] As Figure 1As shown, a flexible solderable circuit in one embodiment of this utility model includes a flexible substrate 10, a circuit layer 11, a pad layer 12, and a protective layer 13. The pad layer 12 further includes a heat-resistant layer 121 and a solder layer 122. The flexible substrate 10 can be a thin layer made of engineering plastic film materials such as PES, LCP, and PI. Preferably, the PI layer made of polyimide (PI) material has a thickness of approximately 50 μm. The circuit layer 11 can be prepared using conductive functional materials made from polymer resins such as polyester, polyurethane, and epoxy resin (e.g., by adding conductive additives such as silver and carbon nanotubes). To ensure the bonding strength between the circuit layer 11 and the flexible substrate 10, a layer structure with a thickness of approximately 5 micrometers is preferably prepared using conductive silver paste made from epoxy resin mixed with silver powder. The heat-resistant layer 121 can be made from a conductive functional material prepared from high-temperature resistant polymer resins such as polyimide (PI), cyanate ester resin, silicone resin, and phenolic resin, along with silver powder. Preferably, it is prepared from conductive silver paste made from phenolic resin and silver powder to obtain an 8-micrometer-thick silver paste layer. Both the circuit layer 11 and the heat-resistant layer 121 can be sequentially deposited onto a flexible substrate using a screen printing process to obtain the corresponding layer structures.

[0033] The solderability of solder pads is one of the key factors determining the reliability of component soldering. To improve the solderability of the solder pad layer 12, the flexible solderable circuit provided by this invention uses metal surface modification technology to deposit a soldering layer 122 (such as a 1-micron copper plating) on ​​a heat-resistant layer 121, including copper plating, tin plating, or gold plating, thus ensuring the reliability of soldering of the solder pad layer 12. The metal surface modification technology can be either electroplating or electroless plating. Compared to electroplating, electroless plating produces a more uniform coating with higher density and smaller pores, and the process is more environmentally friendly and less expensive. The flexible solderable circuit provided by this invention preferably uses electroless gold plating to improve the solderability, corrosion resistance, and service life of the solder pads.

[0034] like Figure 1 As shown, the flexible solderable circuit provided by this utility model also includes a protective layer 13 disposed on the circuit layer 11. The protective layer 13 needs to have a window treatment at the pad layer 12 to facilitate the soldering of components to the pad layer 12. The protective layer 13 can be an insulating ink printing layer or a thin film material hot-pressed layer. The hot-pressing adhesive used in the thin film material hot-pressing process is preferably a thermosetting epoxy adhesive to obtain an epoxy adhesive layer, so as to ensure the bonding strength between the protective layer 13 and the flexible substrate 10. The thickness of the insulating ink printing layer can also be any other value in the range of 10 to 20 μm, and the thickness of the thin film material hot-pressed layer can also be any other value in the range of 25 to 50 μm. As shown in the figure, a hot-pressed epoxy layer with a thickness of 10 micrometers can be used.

[0035] It is apparent for a person skilled in the art that the present application is not limited to the details of the above-described exemplary embodiments, but that it can be implemented in other concrete forms without departing from the spirit or the essential characteristics of the present application. Therefore, the embodiments should be considered as exemplary and non-limiting, the scope of the present application being defined by the claims appended hereto rather than by the above description, and all the changes which fall within the meaning and the scope of the equivalent elements of the claims are intended to be embraced therein. Any reference signs in the claims should not be construed as limiting the claims to the figures in which the reference signs are used.

[0036] Furthermore, it should be understood that although the present specification describes exemplary embodiments, not every embodiment contains only one independent technical solution, and the present specification is described in this way only for the sake of clarity, and a person skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that a person skilled in the art can understand.

Claims

1. A flexible solderable circuit, characterized in that, comprising a flexible substrate, a circuit layer, a pad layer comprising a temperature-resistant layer formed on the circuit layer, a solder layer further formed on the temperature-resistant layer, the temperature-resistant layer being a patterned layer structure obtained by screen printing of conductive silver paste, the solder layer being a layer structure deposited on the temperature-resistant layer of at least any one of: a copper or alloy plating layer, a tin or alloy plating layer, a gold or alloy plating layer, and a protective layer. The flexible substrate is a PES layer or a LCP layer or a PI layer.

2. The flexible solderable circuit of claim 1, wherein, The protective layer is an insulating ink layer or a hot-pressing film material layer.

3. The flexible solderable circuit of claim 1, wherein, The protective layer is formed with a window structure penetrating through the protective layer, the window structure being arranged corresponding to the pad layer to expose the solder sites of the components.

4. The flexible solderable circuit of claim 3, wherein, The window structure is a whole window corresponding to the whole circuit area or a unit window arranged one by one to match each of the solder sites.

5. The flexible solderable circuit of claim 4, wherein, An electronic device comprising the flexible solderable circuit according to any one of claims 1-5 and components electrically connected thereto.

6. Electronic device, characterised in that An electronic device comprising the electronic device according to claim 6.

7. An electronic device, characterized by ​

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