Circuit board with steps

Abstract

The invention discloses a circuit board with steps. The circuit board comprises a base material layer, a conductive layer, an enhancement layer, an insulating layer and a heat dissipation layer, the conductive layers are arranged on the upper and lower surfaces of the base material layer; the enhancement layer covers the bending area of the conductive layer; the insulating layer covers the surface of the enhancement layer; the heat dissipation layer covers the surface of the insulating layer; step type transition structures are arranged between the base material layer and the conductive layer and between the conductive layer and the enhancement layer, the step height is 5-15 microns, and the single-stage step width is 0.1-0.3 mm. The composite material has the advantages of high bending resistance, strong interlayer bonding force and excellent heat dissipation performance.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit boards, and particularly to a circuit board with steps. Background Art

[0002] Circuit boards with steps (FPC) are widely used in electronic devices that need to be bent, such as wearable devices and folding screen mobile phones. In the prior art, the following problems exist in traditional circuit boards with steps:

[0003] 1. When multiple circuit layers are stacked, the circuits are easily broken due to bending;

[0004] 2. The interlayer bonding force is insufficient, and delamination is likely to occur after long-term use;

[0005] 3. The heat dissipation performance is poor, affecting the stability of high-density electronic components.

[0006] Therefore, there is an urgent need for a circuit board with steps having an optimized structure to solve the above problems. Summary of the Invention

[0007] In view of the above problems, the present invention provides a circuit board with steps, which has high bending resistance, strong interlayer bonding force and excellent heat dissipation performance.

[0008] The technical solution of the present invention is as follows:

[0009] A circuit board with steps includes a substrate layer, a conductive layer, a reinforcing layer, an insulating layer and a heat dissipation layer; the conductive layer is disposed on the upper and lower surfaces of the substrate layer; the reinforcing layer covers the bending area of the conductive layer; the insulating layer covers the surface of the reinforcing layer; the heat dissipation layer covers the surface of the insulating layer; a stepped transition structure is provided between the substrate layer and the conductive layer, and between the conductive layer and the reinforcing layer, the step height is 5 - 15 μm, and the width of a single-stage step is 0.1 - 0.3 mm.

[0010] In a further technical solution, the substrate layer is a polyimide film with a thickness of 10 - 50 μm.

[0011] In a further technical solution, the wave crest spacing of the wavy circuit structure of the conductive layer is 0.1 - 0.5 mm.

[0012] In a further technical solution, the connection terminals of the conductive layer adopt a stepped end design and are plated with a gold layer with a thickness of 1 - 3 μm on the surface.

[0013] In a further technical solution, the surface of the step is treated by plasma, the roughness Ra ≥ 0.5 μm, and the step gap is filled with modified epoxy resin.

[0014] In a further technical solution, the stepped transition structures in the bending region of the reinforcing layer and the conductive layer are staggered, and the distance between the two is 0.05 - 0.2 mm.

[0015] The beneficial effects of the present invention are as follows:

[0016] The present invention has high bending resistance, strong interlayer bonding force and excellent heat dissipation performance. Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of the circuit board with steps described in the embodiment of the present invention.

[0018] Description of the reference numerals:

[0019] 10, substrate layer; 20, conductive layer; 30, reinforcing layer; 40, insulating layer; 50, heat dissipation layer. Detailed Embodiments

[0020] The embodiments of the present invention will be further described below with reference to the drawings.

[0021] Embodiment:

[0022] A circuit board with steps, as Figure 1 shown, includes a substrate layer, a conductive layer, a reinforcing layer, an insulating layer and a heat dissipation layer; the conductive layer is disposed on the upper and lower surfaces of the substrate layer and has a wavy circuit structure; the reinforcing layer covers the bending region of the conductive layer; the insulating layer covers the surface of the reinforcing layer; the heat dissipation layer covers the surface of the insulating layer, and the heat dissipation layer includes a composite structure of a graphene film and a metal grid; a stepped transition structure is provided between the substrate layer and the conductive layer, and between the conductive layer and the reinforcing layer, the step height is 5 - 15 μm, and the width of a single-stage step is 0.1 - 0.3 mm.

[0023] In another embodiment, the substrate layer is a polyimide film with a thickness of 10 - 50 μm.

[0024] In another embodiment, the wave crest spacing of the wavy circuit structure of the conductive layer is 0.1 - 0.5 mm.

[0025] In another embodiment, the metal grid of the heat dissipation layer is made of a copper-nickel alloy, and the grid density is 200 - 500 meshes.

[0026] In another embodiment, the connection terminal of the conductive layer adopts a stepped end design, and the surface is plated with a gold layer with a thickness of 1 - 3 μm.

[0027] In another embodiment, the surface of the step is treated by plasma, the surface roughness Ra ≥ 0.5 μm, and the step gap is filled with a modified epoxy resin.

[0028] In another embodiment, the stepped transition structures of the reinforcing layer and the bending region of the conductive layer are staggered, and the distance between the two is 0.05-0.2 mm.

[0029] The above embodiments only represent specific implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A circuit board with a step, characterized in that It includes a substrate layer, a conductive layer, a reinforcing layer, an insulating layer and a heat dissipation layer; the conductive layer is disposed on the upper and lower surfaces of the substrate layer; the reinforcing layer covers the bent area of the conductive layer; the insulating layer covers the surface of the reinforcing layer; the heat dissipation layer covers the surface of the insulating layer; a stepped transition structure is provided between the substrate layer and the conductive layer, and between the conductive layer and the reinforcing layer, the step height is 5 - 15 μm, and the width of a single - stage step is 0.1 - 0.3 mm.

2. The stepped circuit board according to claim 1, characterized in that, The substrate layer is a polyimide film with a thickness of 10 - 50 μm.

3. The circuit board with a step according to claim 1, characterized in that, The peak - to - peak spacing of the wavy line structure of the conductive layer is 0.1 - 0.5 mm.

4. The circuit board with a step according to claim 1, characterized in that, The connection terminals of the conductive layer adopt a stepped end design and are plated with a 1 - 3 μm thick gold layer on the surface.

5. The circuit board with a step according to claim 1, characterized in that, The surface of the step is treated by plasma, the roughness Ra≥0.5 μm, and the step gap is filled with modified epoxy resin.

6. The circuit board with a step according to claim 1, wherein The stepped transition structures of the reinforcing layer and the bent area of the conductive layer are distributed in a staggered manner, and the distance between the two is 0.05 - 0.2 mm.

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