Flexible circuit board and electronic device

Abstract

The utility model discloses a flexible circuit board and an electronic device. Relates to the technical field of circuit boards. The flexible circuit board comprises at least one signal line layer, wherein the signal line layer comprises at least one signal line; the grounding layer is arranged on one side of the signal line layer; the grounding layer at least comprises a grid structure, and the grid structure and the signal lines are at least partially overlapped. According to the utility model, the grounding layer comprises the grid structure, so that the grounding layer with the grid structure is provided with the hollow area, the bending resistance of the grounding layer is improved, the total thickness of the signal line and the grounding layer overlapped by the signal line and the hollow area of the grid structure is relatively thin, the bending resistance of the signal line layer can be improved, and the bending resistance of the signal line layer is improved. The continuity of the signal line can be ensured, the hardness of the flexible circuit board is reduced, the bending resistance of the flexible circuit board is improved, the metal fatigue resistance of the flexible circuit board is improved, the service life of the flexible circuit board is prolonged, and the problems that an existing flexible circuit board is poor in bending resistance, and metal fatigue fracture is prone to occurring at the bending position are solved.

Description

Technical Field

[0001] The embodiments of the utility model relate to the technical field of circuit boards, and in particular to a flexible circuit board and an electronic device. Background Art

[0002] Flexible printed circuit (FPC) is a highly reliable and extremely flexible printed circuit board made of polyimide or polyester film as the substrate. FPC is also called soft circuit board or flexible circuit board. It is favored for its excellent properties such as light weight, thin thickness, and free bending and folding. Conventional PCB is hard and difficult to bend. When bent many times, the bend is prone to metal fatigue and breakage.

[0003] Existing flexible circuit boards have poor bending resistance and are prone to metal fatigue fracture at the bends, which has become a technical problem that needs to be urgently solved in the industry. Utility Model Content

[0004] The embodiments of the utility model provide a flexible circuit board and an electronic device to solve the problem that the existing flexible circuit board has poor bending resistance and is prone to metal fatigue fracture at the bending position.

[0005] In order to achieve the above technical problems, the utility model adopts the following technical solutions:

[0006] The present invention provides a flexible circuit board, comprising:

[0007] at least one signal line layer, wherein the signal line layer comprises at least one signal line;

[0008] A ground layer disposed on one side of the signal line layer;

[0009] The ground layer includes at least a grid structure, and the grid structure at least partially overlaps with the signal line.

[0010] Optionally, the grid structure includes a conductive connecting portion and at least one through hole surrounded by the conductive connecting portion;

[0011] The width of the conductive connection portion is less than or equal to the width of the signal line.

[0012] Optionally, the shape of the through hole includes at least one of a rectangle, a square, a circle or a diamond.

[0013] Optionally, the grid structure includes a first grid structure; the conductive connection portion of the first grid structure includes a first routing portion extending along a first direction and a second routing portion extending along a second direction, and the first direction intersects the second direction;

[0014] An angle between the first routing portion and the second routing portion is greater than or equal to 30° and less than or equal to 60°.

[0015] Optionally, the greater the current density of the ground layer, the smaller the distance between two adjacent first traces of the conductive connection portion;

[0016] The greater the current density of the ground layer, the smaller the distance between two adjacent second traces of the conductive connection portion;

[0017] The distance between two adjacent first routing portions is greater than or equal to 20 mil;

[0018] The distance between two adjacent second wiring portions is greater than or equal to 20 mil.

[0019] Optionally, the line width of the conductive connection portion is greater than or equal to 4 mil and less than or equal to 7 mil.

[0020] Optionally, the grid structure further includes:

[0021] at least one second grid structure;

[0022] The density of the first grid structure is greater than the density of the second grid structure;

[0023] The second grid structure is connected to the first grid structure, and the bending resistance of the second grid structure is greater than the bending resistance of the first grid structure;

[0024] The conductive connection portion of the second grid structure includes a third routing portion extending along a third direction; the third direction intersects the first direction and the second direction;

[0025] The distance between adjacent third routing portions is greater than or equal to the distance between adjacent second routing portions, and / or greater than or equal to the distance between adjacent first routing portions.

[0026] Optionally, an orthographic projection of the signal line on the ground layer at least partially overlaps with the conductive connection portion, and an orthographic projection of the signal line on the ground layer at least partially overlaps with the through hole;

[0027] The uniformity of the resistance of the signal line is greater than a preset resistance uniformity.

[0028] Optionally, the flexible circuit board further includes:

[0029] An insulating layer, disposed between the signal line layer and the ground layer, wherein the signal line is connected to the ground layer through a via hole;

[0030] The material of the ground layer includes conductive metal.

[0031] According to another aspect of the utility model, this embodiment provides an electronic device, including: the flexible circuit board proposed in any item of the first aspect.

[0032] The flexible circuit board provided by the embodiment of the utility model is provided with at least one signal line layer and a ground layer provided on one side of the signal line layer. The ground layer is provided with at least a grid structure. The grid structure and the signal line at least partially overlap, so that the bending resistance of the ground layer is improved, and the total thickness of the signal line and the ground layer overlapped with the hollow area of ​​the grid structure is thinner, which can better improve the bending resistance of the signal line layer, and can also ensure the continuity of the signal line, reduce the hardness of the flexible circuit board, increase the number of bending resistance of the flexible circuit board, improve the metal fatigue resistance of the flexible circuit board, and increase the life of the flexible circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0034] Figure 1 It is a structural schematic diagram of a flexible circuit board provided by an embodiment of the utility model;

[0035] Figure 2 It is a structural schematic diagram of another flexible circuit board provided by an embodiment of the utility model;

[0036] Figure 3 This is a structural schematic diagram of another flexible circuit board provided by an embodiment of the utility model;

[0037] Figure 4 This is a structural schematic diagram of another flexible circuit board provided by an embodiment of the utility model;

[0038] Figure 5 It is a structural schematic diagram of an electronic device provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0039] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0040] Based on the above technical problems, this embodiment proposes the following solutions:

[0041] Figure 1 Schematic diagram of a flexible circuit board provided by the present invention. Figure 1 The flexible circuit board 100 provided in the embodiment of the utility model includes: at least one signal line layer 10, the signal line layer 10 includes at least one signal line 1; a ground layer 20 arranged on one side of the signal line layer 10; the ground layer 20 includes at least a grid structure 2, and the grid structure 2 at least partially overlaps with the signal line 1.

[0042] Specifically, the signal line layer 10 includes at least one signal line 1, and the signal line 1 is used to transmit electrical signals. The circuit board may include a single-layer signal line layer 10, or may include at least two layers of signal line layers 10. When the flexible circuit board includes at least two layers of signal line layers 10, two adjacent layers of signal line layers 10 and the ground layer 20 are insulated from each other to ensure signal transmission and avoid short circuits. The ground layer 20 can cover the entire flexible circuit board. The material of the ground layer 20 includes a conductive metal, for example, a good conductor such as copper or silver.

[0043] By setting the grounding layer 20 to include a grid structure 2, the area of ​​the conductive structure of the grounding layer 20 is reduced, and the conductive structure is not set in the hollow area of ​​the grid structure 2, so that the grounding layer 20 has a stronger bending resistance. By setting the grid structure 2 to at least partially overlap with the signal line 1, when the signal line 1 is extended, it passes through the grid structure 2, so that the total thickness of the signal line 1 and the grounding layer 20 overlapping the hollow area of ​​the grid structure 2 is thinner, which can better improve the bending resistance of the signal line layer 10 and ensure the continuity of the signal line 1, thereby reducing the hardness of the flexible circuit board and increasing the number of bending resistance of the flexible circuit board.

[0044] The flexible circuit board provided in this embodiment is provided with at least one signal line layer 10 and a ground layer 20 provided on one side of the signal line layer 10. The ground layer 20 is provided with at least a grid structure 2. The grid structure 2 at least partially overlaps with the signal line 1, so that the bending resistance of the ground layer 20 is improved, and the total thickness of the signal line 1 and the ground layer 20 overlapping the hollow area of ​​the signal line 1 and the grid structure 2 is thinner, which can better improve the bending resistance of the signal line layer 10, and can also ensure the continuity of the signal line 1, reduce the hardness of the flexible circuit board, increase the number of bending resistance of the flexible circuit board, improve the metal fatigue resistance of the flexible circuit board, and increase the life of the flexible circuit board.

[0045] Optional, Figure 2 FIG. 1 is a schematic diagram of another flexible circuit board provided by an embodiment of the utility model. Figure 2The grid structure 2 includes a conductive connecting portion 21 and at least one through hole 22 surrounded by the conductive connecting portion 21 ; the width of the conductive connecting portion 21 is less than or equal to the width of the signal line 1 .

[0046] Specifically, the conductive connection part 21 is used to ground the flexible circuit board to achieve reliable grounding of the circuit board. The through hole 22 is used to provide a hollow area for the grounding layer 20, thereby further improving the bending resistance of the grounding layer 20. The width of the conductive connection part 21 is set to be less than or equal to the width of the signal line 1, so that the signal line 1 can cross the conductive connection part 21 and the through hole 22, so that the impedance of the signal line 1 is more uniform, and the quality of signal transmission of the signal line 1 is improved.

[0047] Optionally, based on the above embodiment, continue to refer to Figure 2 The shape of the through hole 22 includes at least one of a rectangle, a square, a circle or a diamond.

[0048] Specifically, the shape of the through hole 22 includes at least one of a rectangle, a square, a circle or a diamond, so that the shape of the through hole 22 can be set as needed. The shape of the through hole 22 can be set to include a diamond, which can further improve the continuity of the impedance transmission of the signal line 1, improve the stability of the signal transmitted by the signal line 1, and reduce the loss of the signal transmitted on the signal line 1.

[0049] Optional, Figure 3 FIG. 1 is a schematic diagram of the structure of another flexible circuit board provided by the embodiment of the utility model. Figure 3 The grid structure includes a first grid structure; the conductive connection portion 21 of the first grid structure includes a first routing portion 211 extending along a first direction X and a second routing portion 212 extending along a second direction Y, and the first direction X and the second direction Y intersect; the angle θ between the first routing portion 211 and the second routing portion 212 is greater than or equal to 30° and less than or equal to 60°.

[0050] Specifically, since the angle θ between the first routing portion 211 and the second routing portion 212 is too small, the flexibility between the first routing portion 211 and the second routing portion 212 will be affected. Since the angle θ between the first routing portion 211 and the second routing portion 212 is too large, the first routing portion 211 or the second routing portion 212 will extend in the same direction as the signal line 1, affecting the flexibility of the position of the signal line 1. The angle θ between the first routing portion 211 and the second routing portion 212 is set to be greater than or equal to 30° and less than or equal to 60°, which can not only make the ground layer 20 more flexible, but also make the first routing portion 211 and the second routing portion 212 form a certain angle with the signal line 1, so that the signal line 1 can cross the through hole 22, further improve the bending resistance of the flexible circuit board where the signal line 1 is set, and better control the impedance uniformity and continuity of the signal line 1.

[0051] Optionally, based on the above embodiment, continue to refer to Figure 3 The greater the current density of the grounding layer 20, the smaller the distance between two adjacent first routing lines of the conductive connecting part 21; the greater the current density of the grounding layer 20, the smaller the distance between two adjacent second routing lines of the conductive connecting part 21; the distance between two adjacent first routing parts 211 is greater than or equal to 20 mil; the distance between two adjacent second routing parts 212 is greater than or equal to 20 mil.

[0052] Specifically, due to the different voltages of the flexible circuit board, the current magnitude is also different. When the current is large, the proportion of the conductive connection portion 21 of the ground layer 20 must meet the current density requirements. When the current density requirements are met, the spacing between two adjacent first traces and / or second traces of the conductive connection portion 21 can be set larger to facilitate improving the softness of the conductive layer.

[0053] By setting the distance between two adjacent first routing portions 211 to be greater than or equal to 20 mils, and the distance between two adjacent second routing portions 212 to be greater than or equal to 20 mils, the bending resistance of the first routing portion 211 and the second routing portion 212 can be improved, the hardness of the flexible circuit board can be further reduced, and the number of bending resistance of the flexible circuit board can be further increased.

[0054] Optionally, based on the above embodiment, continue to refer to Figure 3 , the line width of the conductive connection portion 21 is greater than or equal to 4 mil and less than or equal to 7 mil.

[0055] Specifically, such a configuration can better avoid the signal line 1 extending only along the conductive connecting portion 21, and can enable the signal line 1 to cover both the conductive connecting portion 21 and the hollow area formed by the through hole 22, thereby further improving the bending resistance of the flexible circuit board where the signal line 1 is set, and better controlling the impedance uniformity and continuity of the signal line 1.

[0056] Optional, Figure 4 FIG. 1 is a schematic diagram of the structure of another flexible circuit board provided by the embodiment of the utility model. Figure 4 , the grid structure 2 also includes: at least one second grid structure 202; the density of the first grid structure 201 is greater than the density of the second grid structure 202; the second grid structure 202 is connected to the first grid structure 201, and the bending resistance of the second grid structure 202 is greater than the bending resistance of the first grid structure 201; the conductive connection part 21 of the second grid structure 202 includes a third routing part 213 extending along a third direction Z; the third direction Z intersects with the first direction X and the second direction Y; the distance between adjacent third routing parts 213 is greater than or equal to the distance between adjacent second routing parts 212, and / or, greater than or equal to the distance between adjacent first routing parts 211.

[0057] Specifically, according to the working requirements of the flexible circuit board, under the premise of achieving better overall bending ability, a second grid structure 202 with a lower density can be set in the area that needs to be bent repeatedly, so that the flexible circuit board can be bent multiple times through the bending-resistant second grid structure 202, and the bending resistance and service life of the flexible circuit board are further improved. It should be noted that the extension direction of the third routing portion 213 of the second grid structure 202 can be the same as or different from the extension direction of the first routing portion 211 or the second routing portion 212 of the first grid structure 201, and no limitation is made here. Optionally, the extension direction of the third routing portion 213 of the second grid structure 202 can be the same as the extension direction of the signal line 1, and no limitation is made here.

[0058] Optionally, based on the above embodiment, continue to refer to Figure 3 , the orthographic projection of the signal line 1 on the ground layer 20 at least partially overlaps with the conductive connecting portion 21, and the orthographic projection of the signal line 1 on the ground layer 20 at least partially overlaps with the through hole 22; the uniformity of the resistance of the signal line 1 is greater than the preset resistance uniformity.

[0059] Specifically, by setting the orthographic projection of the signal line 1 on the ground layer 20 to at least partially overlap with the conductive connection part 21, and the orthographic projection of the signal line 1 on the ground layer 20 to at least partially overlap with the through hole 22, the orthographic projection of the signal line 1 on the ground layer 20 overlaps with both the conductive connection part 21 and the through hole 22, thereby further improving the bending resistance of the flexible circuit board where the signal line 1 is set. By setting the uniformity of the resistance of the signal line 1 to be greater than the preset resistance uniformity, the impedance of the signal line 1 is relatively uniform, which can better reduce the reflection of the signal transmitted on the signal line 1, and improve the reliability and signal transmission efficiency of the flexible circuit board.

[0060] Optionally, based on the above embodiment, continue to refer to Figure 3 The flexible circuit board may further include: an insulating layer (not shown in the figure), which is arranged between the signal line layer 10 and the ground layer 20, and the signal line 1 is connected to the ground layer 20 through a via; the material of the ground layer 20 includes a conductive metal.

[0061] Specifically, the insulating layer includes an interlayer insulating layer of the flexible circuit board, and the insulating layer can be provided with at least one insulating layer according to the number of the signal line layer 10 and the ground layer 20. The insulating layer can effectively insulate the signal line layer 10 and the ground layer 20, and better avoid the short circuit fault between the signal line 1 and the ground layer 20. By providing the insulating layer, the multilayer board design of the flexible circuit board can be realized, the reasonable wiring of the flexible circuit board can be better realized, and the size of the flexible circuit board can be reduced. Exemplarily, the material of the ground layer 20 includes a conductive metal, such as copper foil. The conductive connection part of the grid structure is copper foil, and the through hole is the area where the copper foil is hollowed out.

[0062] This embodiment provides an electronic device. Figure 5 Schematic diagram of the structure of an electronic device provided by the embodiment of the utility model. Figure 5 The electronic device 200 provided in this embodiment includes the flexible circuit board 100 proposed in any of the above embodiments, and has the beneficial effects of the flexible circuit board 100 proposed in any of the above embodiments, which will not be repeated here.

[0063] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A flexible circuit board, characterized in that: include: at least one signal line layer, wherein the signal line layer comprises at least one signal line; A ground layer disposed on one side of the signal line layer; The ground layer includes at least a grid structure, and the grid structure at least partially overlaps with the signal line.

2. The flexible circuit board according to claim 1, characterized in that: The grid structure includes a conductive connecting portion and at least one through hole surrounded by the conductive connecting portion; The width of the conductive connection portion is less than or equal to the width of the signal line.

3. The flexible circuit board according to claim 2, characterized in that: The shape of the through hole includes at least one of a rectangle, a square, a circle or a diamond.

4. The flexible circuit board according to claim 2, characterized in that: The grid structure includes a first grid structure; The conductive connection portion of the first grid structure includes a first routing portion extending along a first direction and a second routing portion extending along a second direction, wherein the first direction intersects the second direction; An angle between the first routing portion and the second routing portion is greater than or equal to 30° and less than or equal to 60°.

5. The flexible circuit board according to claim 4, characterized in that: The greater the current density of the ground layer, the smaller the distance between two adjacent first traces of the conductive connection portion; The greater the current density of the ground layer, the smaller the distance between two adjacent second traces of the conductive connection portion; The distance between two adjacent first routing portions is greater than or equal to 20 mil; The distance between two adjacent second wiring portions is greater than or equal to 20 mil.

6. The flexible circuit board according to claim 2, characterized in that: The line width of the conductive connection portion is greater than or equal to 4 mil and less than or equal to 7 mil.

7. The flexible circuit board according to claim 4, characterized in that: The grid structure further includes: at least one second grid structure; The density of the first grid structure is greater than the density of the second grid structure; The second grid structure is connected to the first grid structure, and the bending resistance of the second grid structure is greater than the bending resistance of the first grid structure; The conductive connection portion of the second grid structure includes a third routing portion extending along a third direction; the third direction intersects the first direction and the second direction; The distance between adjacent third routing portions is greater than or equal to the distance between adjacent second routing portions, and / or greater than or equal to the distance between adjacent first routing portions.

8. The flexible circuit board according to claim 2, characterized in that: The orthographic projection of the signal line on the ground layer at least partially overlaps with the conductive connection portion, and the orthographic projection of the signal line on the ground layer at least partially overlaps with the through hole; The uniformity of the resistance of the signal line is greater than a preset resistance uniformity.

9. The flexible circuit board according to claim 1, characterized in that: The flexible circuit board further includes: An insulating layer, disposed between the signal line layer and the ground layer, wherein the signal line is connected to the ground layer through a via hole; The material of the ground layer includes conductive metal.

10. An electronic device, characterized in that: include: The flexible circuit board according to any one of claims 1 to 9.

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