Black copper-clad plate and flexible circuit board

Abstract

In order to solve the problem that a black base material of an existing flexible circuit board is insufficient in shading performance, the utility model provides a black copper-clad plate and a flexible circuit board, the black copper-clad plate comprises an ink layer, an adhesive film layer, an adhesive layer and a copper foil layer, the ink layer is located on the surface of one side of the adhesive film layer, and the adhesive layer is located on the surface of the other side of the adhesive film layer. The adhesive layer is located on the surface, deviating from the ink layer, of the adhesive film layer, the copper foil layer is located on the surface, deviating from the adhesive layer, of the adhesive layer, and the ink layer, the adhesive film layer and the adhesive layer are all black layers. According to the black copper-clad plate provided by the utility model, the black ink layer, the adhesive film layer and the binder layer are adopted, and the problem of light leakage of a single black layer can be effectively solved by utilizing the mutual shielding effect among different layers, so that a better light shielding effect is achieved.

Description

Technical Field

[0001] This utility model belongs to the field of flexible circuit board technology, specifically relating to a black copper-clad laminate and a flexible circuit board. Background Technology

[0002] With the development of the gaming keyboard market, backlit keyboards are increasingly favored by consumers. Backlit keyboards offer a comfortable feel, improve operational efficiency, and make keys easier to spot at night, enhancing the gaming experience. Their stylish design has also made them popular among young consumers. Furthermore, many gaming keyboard manufacturers have launched more new types of backlit keyboards, such as RGB keyboards and mechanical touch keyboards. As the market demand for backlit keyboards grows rapidly, the black opaque substrate of the FPC (flexible printed circuit board) inside has also gained popularity, and demand is gradually increasing.

[0003] Currently available black substrates are generally matte, but their light-blocking effect is poor and cannot meet the special requirements of shielding under light sources. Alternatively, PET substrates coated with black ink have poor heat resistance and low light-blocking rate, and small light spots can still be seen under strong light.

[0004] Existing black substrates are difficult to achieve the required light-blocking rate when they are thin. To improve the light-blocking rate of black substrates without changing the thickness, the amount of carbon black added can be increased. However, adding too much carbon black will bring many problems, such as poor compatibility, easy separation and sedimentation of adhesive, reduced adhesion between adhesive and substrate, reduced resistance, and inability to meet the dielectric constant requirements of electronic products. Utility Model Content

[0005] To address the problem of insufficient light-shielding properties of existing black substrates for flexible circuit boards, this invention provides a black copper-clad laminate and a flexible circuit board.

[0006] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows:

[0007] On one hand, the present invention provides a black copper-clad laminate, comprising an ink layer, an adhesive film layer, an adhesive layer and a copper foil layer. The ink layer is located on one side surface of the adhesive film layer, the adhesive layer is located on the adhesive film layer on the surface opposite to the ink layer, and the copper foil layer is located on the adhesive layer on the surface opposite to the adhesive layer. The ink layer, the adhesive film layer and the adhesive layer are all black layers.

[0008] Optionally, the ink layer is a black matte layer.

[0009] Optionally, the ink layer is selected from black polyester resin ink.

[0010] Optionally, the adhesive film layer is selected from black polyimide adhesive film.

[0011] Optionally, the adhesive layer is selected from black epoxy adhesive layers.

[0012] Optionally, the thickness of the ink layer is 10~30μm, the thickness of the adhesive film layer is 10~50μm, the thickness of the adhesive layer is 10~50μm, and the thickness of the copper foil layer is 12~70μm.

[0013] Optionally, the black copper-clad laminate further includes a substrate, the ink layer is located on one side surface of the substrate, and the adhesive film layer is located on the surface of the ink layer facing away from the substrate.

[0014] Optionally, the substrate is selected from PET film.

[0015] Optionally, the thickness of the supporting base layer is 36~75μm.

[0016] In another aspect, the present invention provides a flexible circuit board, including the black copper-clad laminate as described above.

[0017] The black copper-clad laminate provided by this utility model adopts a three-layer combination structure of ink layer, adhesive film layer and adhesive layer. The ink layer, adhesive film layer and adhesive layer are all black layers. By utilizing the mutual shielding effect between different layers, the light leakage problem of a single black layer can be effectively solved, achieving a better light shielding effect. Moreover, the adhesive film layer and adhesive layer are functional structural layers of the flexible circuit board itself, while the ink layer is generally thin and will not significantly change the thickness of the black copper-clad laminate, ensuring good flexibility and deformability. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a black copper-clad laminate provided in one embodiment of the present invention;

[0019] The reference numerals in the accompanying drawings are as follows:

[0020] 1. Substrate; 2. Ink layer; 3. Adhesive film layer; 4. Adhesive layer; 5. Copper foil layer. Detailed Implementation

[0021] To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0022] In the description of this utility model, it should be understood that the terms "thickness", "upper", "lower", etc., 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, they should not be construed as limitations on this utility model.

[0023] See Figure 1 As shown, one embodiment of this utility model provides a black copper-clad laminate, including an ink layer 2, an adhesive film layer 3, an adhesive layer 4, and a copper foil layer 5. The ink layer 2 is located on one side surface of the adhesive film layer 3, the adhesive layer 4 is located on the adhesive film layer 3 away from the surface of the ink layer 2, and the copper foil layer 5 is located on the adhesive layer 4 away from the surface of the adhesive layer 4. The ink layer 2, the adhesive film layer 3, and the adhesive layer 4 are all black layers.

[0024] The black copper-clad laminate provided by this utility model adopts a three-layer combination structure of ink layer 2, adhesive film layer 3 and adhesive layer 4. The ink layer 2, adhesive film layer 3 and adhesive layer 4 are all black layers. By utilizing the mutual shielding effect between different layers, the light leakage problem existing in a single black layer can be effectively solved, achieving a better light shielding effect. Moreover, the adhesive film layer 3 and adhesive layer 4 are functional structural layers of the flexible circuit board itself, while the ink layer 2 is generally thin and will not significantly change the thickness of the black copper-clad laminate, ensuring good flexibility and deformability.

[0025] The method for preparing the black copper-clad laminate is as follows: first, an ink layer 2 is applied to the adhesive film layer 3, and then an adhesive layer 4 is applied to the other side of the adhesive film layer 3. The two layers are then pressed together with the copper foil layer 5 to cure the laminate and finally obtain the black copper-clad laminate.

[0026] In one embodiment, the ink layer 2 is a black matte layer.

[0027] Existing black adhesive films mainly achieve a matte finish by adding black fillers, while inks can achieve a matte finish by adding matting agents. By using matte black ink, the matte finish of the black copper-clad laminate can be achieved through the ink layer 2. Compared with glossy ink, matte ink is more conducive to improving the light-blocking effect.

[0028] In one embodiment, the ink layer 2 is selected from black polyester resin ink.

[0029] Specifically, the black polyester resin ink can be obtained commercially or made in-house.

[0030] In one embodiment, the black polyester resin ink comprises the following components by weight:

[0031] Polyester resin 30-60 parts, carbon black 5-10 parts, matting agent 3-6 parts, titanium dioxide 3-6 parts, main curing agent 10-20 parts, and secondary curing agent 5-10 parts.

[0032] The black polyester resin ink maintains low matte finish and high opacity while exhibiting good resistance to yellowing, non-sticking at high temperatures, and non-dissolving and peeling under various acid and alkali conditions.

[0033] In one embodiment, the carbon black is selected from NEROX 600 carbon black.

[0034] In one embodiment, the matting agent is selected from Evonik OK607 silica matting agent.

[0035] In one embodiment, the primary curing agent is selected from Covestro Desmodur N 3390 curing agent, and the secondary curing agent is selected from EVONIK VESTANAT T1890.

[0036] In one embodiment, the adhesive film layer 3 is selected from black polyimide adhesive film.

[0037] The black polyimide film is a carbon black-doped polyimide. The polyimide is formed by polycondensation and casting of pyromellitic dianhydride (PMDA) and diaminodiphenyl ether (DDE) in a strongly polar solvent, followed by imidization. It has excellent high and low temperature resistance, electrical insulation, adhesion, radiation resistance, and dielectric resistance. It can be used for a long time in a temperature range of -269℃ to 280℃, and can reach a high temperature of 400℃ for short periods. It is particularly suitable as a substrate for flexible printed circuit boards and various high-temperature resistant electrical appliance insulation materials.

[0038] In one embodiment, the adhesive layer 4 is selected from black epoxy adhesive layers.

[0039] The black epoxy adhesive layer is an epoxy resin doped with carbon black or other black fillers.

[0040] In one embodiment, the ink layer 2 has a thickness of 10-30 μm, the adhesive film layer 3 has a thickness of 10-50 μm, the adhesive layer 4 has a thickness of 10-50 μm, and the copper foil layer 5 has a thickness of 12-70 μm.

[0041] In one embodiment, the black copper-clad laminate further includes a substrate 1, the ink layer 2 is located on one side surface of the substrate 1, and the adhesive film layer 3 is located on the surface of the ink layer 2 facing away from the substrate 1.

[0042] The supporting base layer 1 serves two purposes: firstly, it supports the ink layer 2, the adhesive film layer 3, the adhesive layer 4, and the copper foil layer 5, thereby improving the overall mechanical strength of the black copper-clad laminate; secondly, it also protects the ink layer 2, preventing it from aging and peeling off due to exposure or surface damage caused by external friction.

[0043] In one embodiment, the substrate 1 is selected from PET film.

[0044] PET film can provide both good protection and flexibility.

[0045] In one embodiment, the thickness of the supporting base layer 1 is 36~75μm.

[0046] If the thickness of the supporting substrate 1 is too low, it will be difficult to protect the ink layer 2, and it will be prone to cracking under external forces; if the thickness of the supporting substrate 1 is too high, it will lead to an increase in the overall thickness of the black copper-clad laminate, affecting the deformability of the flexible circuit board subsequently prepared.

[0047] Another embodiment of the present invention provides a flexible circuit board, including the black copper-clad laminate as described above.

[0048] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A black copper-clad laminate, characterized in that, It includes an ink layer, an adhesive film layer, an adhesive layer, and a copper foil layer. The ink layer is located on one side surface of the adhesive film layer, the adhesive layer is located on the adhesive film layer on the surface opposite to the ink layer, and the copper foil layer is located on the adhesive layer on the surface opposite to the adhesive layer. The ink layer, the adhesive film layer, and the adhesive layer are all black layers.

2. The black copper-clad laminate according to claim 1, characterized in that, The ink layer is a black matte layer.

3. The black copper-clad laminate according to claim 2, characterized in that, The ink layer is selected from black polyester resin ink.

4. The black copper-clad laminate according to claim 1, characterized in that, The adhesive film layer is selected from black polyimide adhesive film.

5. The black copper-clad laminate according to claim 1, characterized in that, The adhesive layer is selected from black epoxy adhesive layers.

6. The black copper-clad laminate according to claim 1, characterized in that, The thickness of the ink layer is 10~30μm, the thickness of the adhesive film layer is 10~50μm, the thickness of the binder layer is 10~50μm, and the thickness of the copper foil layer is 12~70μm.

7. The black copper-clad laminate according to claim 1, characterized in that, The black copper-clad laminate also includes a substrate, the ink layer is located on one side of the substrate, and the adhesive film layer is located on the surface of the ink layer facing away from the substrate.

8. The black copper-clad laminate according to claim 7, characterized in that, The supporting substrate is selected from PET film.

9. The black copper-clad laminate according to claim 7, characterized in that, The thickness of the supporting base layer is 36~75μm.

10. A flexible circuit board, characterized in that, Including the black copper-clad laminate as described in any one of claims 1 to 9.

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