Multilayer circuit board and electronic device

Abstract

Provided in the present application are a multilayer circuit board and an electronic device. The multilayer circuit board comprises a circuit unit layer, wherein the circuit unit layer comprises at least two circuit layers arranged parallel to and spaced apart from each other, and an insulating layer sandwiched between adjacent circuit layers; surfaces arranged opposite each other in the direction of thickness of the circuit unit layer are a first side surface and a second side surface; the circuit unit layer is provided with via holes penetrating the circuit unit layer in the direction of thickness thereof; the via holes are defined by inner side walls; the first side surface or the second side surface is provided with a first copper plating layer; second copper plating layers connected to the first copper plating layer are plated on the inner side walls; and the at least two circuit layers are connected in parallel by means of the second copper plating layers. The multilayer circuit board of the present application achieves parallel connection between the circuit layers, effectively controls the resistance value of the circuit board and meets performance requirements while reducing the overall thickness of the multilayer circuit board and lowering the space requirements for mounting the multilayer circuit board.

Description

A multilayer circuit board and electronic device Technical Field

[0001] This application relates to the field of circuit board technology, specifically to a multilayer circuit board and electronic equipment. Background Technology

[0002] With the rapid development of electronic products, different electronic products have different resistance values, and some electronic products have resistance value limitations in circuit design. In existing electronic products, reducing the circuit resistance of the circuit board can usually be achieved by reducing the circuit line length, increasing the conductor thickness, and increasing the conductor line width. However, due to the space limitations of the installation structure of electronic products, it is not possible to reduce the resistance by increasing the conductor thickness.

[0003] Therefore, it is necessary to provide a multilayer circuit board and electronic device that can meet the requirements in terms of both installation space and resistance performance. Technical issues

[0004] The purpose of this application is to provide a multilayer circuit board with a small thickness, which can meet the structural space requirements of the product, and at the same time, it can effectively control the resistance value and meet the performance requirements of electronic products for resistance value. Technical solutions

[0005] The technical solution of this application is as follows:

[0006] In a first aspect, this application provides a multilayer circuit board, which includes a circuit unit layer; the circuit unit layer includes at least two circuit layers arranged in parallel and spaced apart from each other and an insulating layer sandwiched between adjacent circuit layers; the surfaces arranged opposite to each other along the thickness direction of the circuit unit layer are a first side surface and a second side surface; a through hole is formed on the circuit unit layer through its thickness direction, the through hole is formed by an inner side wall, a first copper plating layer is provided only on the first side surface or the second side surface, and a second copper plating layer connected to the first copper plating layer is plated on the inner side wall, and at least two circuit layers are connected in parallel through the second copper plating layer.

[0007] Optionally, the end of the second copper plating layer opposite to the first copper plating layer is flush with one of the first side surface and the second side surface where the first copper plating layer is not disposed.

[0008] Optionally, the circuit unit layer further includes an outer wall disposed opposite to the inner sidewall, and the first copper plating layer extends to be flush with the outer sidewall.

[0009] Optionally, the number of through holes is multiple, and the multiple through holes are spaced apart.

[0010] Optionally, the line unit layer includes three line layers that are evenly spaced apart from each other and two insulating layers that are respectively disposed between adjacent line layers.

[0011] Optionally, the three circuit layers have the same line length, and the three circuit layers are connected in parallel through the second copper plating layer in the via.

[0012] Optionally, the three circuit layers are not completely identical, and the three circuit layers are connected in parallel through a second copper plating layer in the via.

[0013] Optionally, the through hole is a cylindrical hole.

[0014] Optionally, the circuit board may be a flexible circuit board, a rigid circuit board, or a rigid-flex circuit board.

[0015] Secondly, this application provides an electronic device comprising a multilayer circuit board as described above. The electronic device includes a voice coil motor. Beneficial effects

[0016] The beneficial effects of this application are as follows:

[0017] The multilayer circuit board described in this application includes a first copper plating layer disposed on a first or second side surface of the circuit unit layer, and a second copper plating layer disposed on the inner sidewall of the via; the second copper plating layer is connected to the first copper plating layer. This multilayer circuit board structure, where the first copper plating layer is plated only on one side surface of the circuit unit layer, and no copper plating layer is disposed on the other side of the circuit unit layer, thickens only one side of the circuit unit layer in the thickness direction. This achieves parallel connection between the circuit layers, effectively controls the resistance value of the circuit board, meets performance requirements, while reducing the overall thickness of the multilayer circuit board and lowering the space requirements for installation. The first copper plating layer forms a protective layer for the circuit layers and, to a certain extent, increases the thickness of the conductors and reduces the resistance value of the multilayer circuit board. Attached Figure Description

[0018] Figure 1 is a cross-sectional schematic diagram of the multilayer circuit board of this application.

[0019] Figure 2 is a schematic diagram of the surface of the multilayer circuit board of this application that is not covered with the first copper plating layer.

[0020] Figure 3 is another structural schematic diagram of the surface of the multilayer circuit board of this application that is not covered with the first copper plating layer. Embodiments of the present invention

[0021] The present application will be further described below with reference to the accompanying drawings and embodiments.

[0022] In a first aspect, this application provides a multilayer circuit board, as shown in Figures 1 to 3, which includes a circuit unit layer 10; the circuit unit layer 10 includes at least two parallel and spaced circuit layers 11 and an insulating layer 12 sandwiched between adjacent circuit layers 11; the surfaces arranged opposite to each other along the thickness direction of the circuit unit layer 10 are a first side surface 14 and a second side surface 15; the circuit unit layer 10 has a through hole 13 extending along its thickness direction, the through hole 13 is formed by an inner sidewall 16, only the first side surface 14 or the second side surface 15 is provided with a first copper plating layer 20, the inner sidewall 16 is plated with a second copper plating layer 30 connected to the first copper plating layer 20, and at least two circuit layers 11 are connected in parallel through the second copper plating layer 30. That is, the circuit unit layer 10 is formed by stacking the insulating layer 12 and the circuit layers 11 to form two opposing surfaces, and the first copper plating layer 20 is provided on one of the side surfaces.

[0023] The multilayer circuit board described in this application includes a first copper plating layer 20 disposed on a first side surface 14 or a second side surface 15 of the circuit unit layer 10, and a second copper plating layer 30 disposed on the inner sidewall 16 of the via 13; the second copper plating layer 30 is connected to the first copper plating layer 20. In this multilayer circuit board structure, the first copper plating layer 20 is plated only on one side surface of the circuit unit layer 10, while the other side of the circuit unit layer 10 is not provided with the first copper plating layer 20. In the thickness direction, only one side of the circuit unit layer 10 is thickened. This reduces the overall thickness of the multilayer circuit board and lowers the space requirements for installation while achieving parallel connection between the circuit layers 11, effectively controlling the resistance value of the circuit board, and meeting performance requirements. The first copper plating layer 20 forms a protective layer for the circuit layers 11 and, to a certain extent, increases the conductor thickness and reduces the resistance value of the multilayer circuit board.

[0024] Optionally, the end of the second copper plating layer 30 facing away from the first copper plating layer 20 is flush with the surface where the first copper plating layer 20 is not provided.

[0025] Optionally, the circuit unit layer 10 may further include an outer wall 17 disposed opposite to the inner wall 16, wherein the first copper plating layer 20 extends to be flush with the outer wall 17.

[0026] Referring to Figure 3, optionally, there can be multiple vias 13, spaced apart. The vias 13 enable parallel connections between the circuit layers 11. A greater number of vias 13 results in a larger resistance reduction, allowing for more effective control over the resistance value of the multilayer circuit board. It is understood that the number of vias 13 can be specifically set according to actual performance requirements.

[0027] Optionally, the circuit layer 11 is made of copper; the insulating layer 12 is made of a composite material of insulating material and adhesive.

[0028] Optionally, the insulating material includes one or more of insulating ink, polyimide, or polyethylene naphthalate.

[0029] Referring to Figure 1, in a specific embodiment of this application, the circuit unit layer 10 includes three parallel and spaced circuit layers 11 and two insulating layers 12 respectively disposed between adjacent circuit layers 11; the circuit layers 11 and the insulating layers 12 are stacked sequentially, with the insulating layers 12 sandwiched between the circuit layers 11; the through holes 13 are disposed through the circuit unit layer 10 along the thickness direction.

[0030] The three parallel circuit layers 11 are connected in parallel through the via 13, thereby effectively controlling the circuit resistance and reducing excessive heat generation during circuit operation. The other side of the circuit unit layer 10 is not plated with copper, which reduces the overall thickness of the multilayer circuit board and reduces the installation space required for installation.

[0031] Optionally, the insulating layer 12 may be a single-layer structure made of a composite material of insulating material and adhesive, or a multi-layer structure formed by stacking a single-layer structure made of a composite material of insulating material and adhesive multiple times; of course, the circuit layer 11 is not limited to a single-layer structure; by setting different circuit layers 11, the parallel design between circuit layers 11 can be adjusted.

[0032] Optionally, the three circuit layers have the same line length, and the three circuit layers are connected in parallel through a second copper plating layer in the via.

[0033] Optionally, the three circuit layers are not completely identical, and the three circuit layers are connected in parallel through a second copper plating layer in the via.

[0034] Optionally, as shown in Figures 2 and 3, the through hole 13 is a cylindrical hole, that is, the cross-section of the through hole 13 is circular.

[0035] Optionally, the multilayer circuit board may be a flexible printed circuit (FPC), a rigid printed circuit board (PCB), or a rigid-flex PCB.

[0036] Secondly, this application provides an electronic device comprising a multilayer circuit board as described above. The electronic device includes a voice coil motor (VCM).

[0037] The above description is merely an embodiment of this application. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of this application, but these improvements all fall within the protection scope of this application.

Claims

1. A multilayer circuit board, characterized in that, The system includes a circuit unit layer; the circuit unit layer includes at least two parallel and spaced circuit layers and an insulating layer sandwiched between adjacent circuit layers; the surfaces arranged opposite each other along the thickness direction of the circuit unit layer are a first side surface and a second side surface; the circuit unit layer has a through hole that extends along its thickness direction, the through hole is formed by an inner side wall, only the first side surface or the second side surface has a first copper plating layer, the inner side wall is plated with a second copper plating layer connected to the first copper plating layer, and at least two circuit layers are connected in parallel through the second copper plating layer.

2. The multilayer circuit board according to claim 1, characterized in that, The end of the second copper plating layer opposite to the first copper plating layer is flush with one of the first side surface and the second side surface where the first copper plating layer is not disposed.

3. The multilayer circuit board according to claim 1, characterized in that, The circuit unit layer also includes an outer wall disposed opposite to the inner wall, and the first copper plating layer extends to be flush with the outer wall.

4. The multilayer circuit board according to claim 1, characterized in that, The number of through holes is multiple, and the multiple through holes are arranged at intervals.

5. The multilayer circuit board according to claim 1, characterized in that, The circuit unit layer includes three parallel and spaced circuit layers and two insulating layers disposed between adjacent circuit layers.

6. The multilayer circuit board according to claim 5, characterized in that, The three circuit layers have the same line length and are connected in parallel through the second copper plating layer in the via.

7. The multilayer circuit board according to claim 5, characterized in that, The three circuit layers are not completely identical, and the three circuit layers are connected in parallel through the second copper plating layer in the via.

8. The multilayer circuit board according to claim 1, characterized in that, The through hole is a cylindrical hole.

9. The multilayer circuit board according to claim 3, characterized in that, The multilayer circuit board is one of a flexible circuit board, a rigid circuit board, or a rigid-flex circuit board.

10. An electronic device, characterized in that, The electronic device includes the multilayer circuit board as described in claim 1.

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