CN216982207U

CN216982207U - Flexible circuit board

Info

Publication number: CN216982207U
Application number: CN202220013807.9U
Authority: CN
Inventors: 李成毅; 曾杰; 唐笑语; 郭文峰; 李飞; 陈志龙; 刘国彦; 杨广杰; 薛孝忠; 王静
Original assignee: BOE Technology Group Co Ltd; Chengdu BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Chengdu BOE Optoelectronics Technology Co Ltd
Priority date: 2022-01-05
Filing date: 2022-01-05
Publication date: 2022-07-15
Anticipated expiration: 2032-01-05

Abstract

The utility model relates to a flexible circuit board which comprises a windowing area, a non-windowing area, a first golden finger and a second golden finger, wherein the first golden finger and the second golden finger are positioned in the windowing area, the first golden finger and the second golden finger are arranged in parallel and adjacent, the pressure difference between the first golden finger and the second golden finger is larger than zero, and the flexible circuit board further comprises a blocking structure so as to increase the distance between the first golden finger and one end, close to the non-windowing area, of the second golden finger.

Description

Flexible circuit board

Technical Field

The utility model relates to the technical field of display product manufacturing, in particular to a flexible circuit board.

Background

The flexible display product needs to be connected with its PNL Bump (metal Bump on the display panel) through a COF Bump (metal Bump on the flip chip film) or an MFPC Bump (metal Bump on the flexible circuit board), so as to ensure the transmission of electrical signals, wherein the GOA signal, the VGH signal, and the VGL signal are some high and low signals with varying voltages. In the design of some products, high and low signals are arranged side by side, and due to the windowing design of a COF or MFPC binding area, water vapor cannot be completely blocked after ACF glue or UV glue is coated, so that water vapor is gathered between the high and low signals in the reliability process to cause short circuit, further electrochemical corrosion is generated, and finally poor display of a screen is caused.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problems, the utility model provides a flexible circuit board which solves the problem that a screen is poor in display due to short circuit and even electrochemical corrosion caused by water vapor accumulated between high and low signals.

In order to achieve the purpose, the embodiment of the utility model adopts the technical scheme that: the utility model provides a flexible circuit board, includes windowing district, non-windowing district, and is located windowing district's first golden finger and second golden finger, first golden finger with the parallel and adjacent setting of second golden finger, just first golden finger with pressure differential between the second golden finger is greater than zero, flexible circuit board still includes and blocks the structure, in order to increase first golden finger with the second golden finger is close to the interval of the one end in non-windowing district.

Optionally, the window structure comprises a substrate layer, a conductive layer and a protective layer which are sequentially stacked, wherein the protective layer covers a part of the conductive layer to form the windowing region and the non-windowing region;

the blocking structure comprises a concave-convex structure formed at the junction of the non-windowing area and the windowing area along a first direction, the concave-convex structure comprises a protrusion and a recess, the orthographic projection of the first golden finger on the non-windowing area is located in the protrusion, the orthographic projection of the second golden finger on the non-windowing area is located in the recess, and the first direction is the extending direction of the first golden finger.

Optionally, the non-windowing region includes a first region and a second region that are adjacently disposed, the protrusion is formed by extending the first region in a direction close to the windowing region, and/or the recess is formed by recessing the second region in a direction away from the windowing region.

Optionally, the concave-convex structure is formed when the protective layer is cut to form the windowing region.

Optionally, the shape of the cross section of the concave-convex structure in the direction parallel to the substrate layer is a wave shape.

Optionally, in the extending direction of the first gold finger, the distance between the central points of the adjacent wave crests and wave troughs of the wave shape is 50-70 um.

Optionally, the blocking structure includes a dummy gold finger disposed between the first gold finger and the second gold finger, and the dummy gold finger is disposed in parallel with the first gold finger.

Optionally, a green oil protection layer is arranged between the non-windowing region and the windowing region.

Optionally, the conductive layer is made of copper.

Optionally, the protective layer includes a covering film layer covering the conductive layer, and an electromagnetic shielding film layer disposed on one side of the covering film layer away from the conductive layer.

The utility model has the beneficial effects that: through the arrangement of the blocking structure, the distance between the first golden finger and one end, close to the non-windowing area, of the second golden finger is increased, the risk of short circuit between the first golden finger and the second golden finger is reduced, and therefore poor display caused by signal short circuit can be improved.

Drawings

FIG. 1 is a first schematic diagram illustrating a structure of a flexible printed circuit board according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a flexible printed circuit board according to an embodiment of the utility model;

FIG. 3 is a schematic diagram of a flexible circuit board according to an embodiment of the present invention;

fig. 4 shows a fourth schematic structural diagram of the flexible circuit board in the embodiment of the utility model.

1, a windowing area; 2 a non-windowed area; 3, a concave-convex structure; 31 a projection; 32 concave parts; 10 a first golden finger; 20 second golden finger; 30 virtual golden fingers; 101 a base material layer; 102 a first conductive layer; 103 a first cover film layer; 104 a first electromagnetic shielding layer; 202 a second conductive layer; 203 a second cover film layer; 204 a second electromagnetic shielding layer; 100 green oil protective layer; 200 glue layers.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the description of the embodiments of the utility model given above, are within the scope of protection of the utility model.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Referring to fig. 1 to 4, the present embodiment provides a flexible circuit board, which includes a windowing region 1, a non-windowing region 2, and a first gold finger 10 and a second gold finger 20 located in the windowing region 1, where the first gold finger 10 and the second gold finger 20 are parallel and adjacently disposed, a pressure difference between the first gold finger 10 and the second gold finger 20 is greater than zero, and the flexible circuit board further includes a blocking structure to increase a distance between the first gold finger 10 and the second gold finger 20 at a junction of the windowing region 1 and the non-windowing region 2.

Through the arrangement of the blocking structure, the distance between the first golden finger 10 and one end of the second golden finger 20 close to the non-windowing area 2 is increased, the risk of short circuit between the first golden finger 10 and the second golden finger 20 is reduced, and therefore poor display caused by signal short circuit can be improved.

The specific structural form of the blocking structure may be various, and in this embodiment, for example, the flexible circuit board includes a substrate layer 101, a conductive layer, and a protective layer, which are sequentially stacked, where the protective layer covers a part of the conductive layer to form the windowing region 1 and the non-windowing region 2;

the blocking structure includes a concave-convex structure 3 formed at a junction of the non-windowed area 2 and the windowed area 1 along a first direction (refer to an X direction shown in fig. 2), where the concave-convex structure 3 includes a protrusion 31 and a recess 32, along the first direction, an orthographic projection of the first gold finger 10 on the non-windowed area 2 is located in the protrusion 31, an orthographic projection of the second gold finger 20 on the non-windowed area 2 is located in the recess 32, and the first direction is an extending direction of the first gold finger 10.

Generally, the space reserved for manufacturing the golden fingers on the flexible circuit board (MFPC or COF) is limited, and when the size of the flexible circuit board is continuously compressed, it is very challenging to put down all transmission signals in the limited reserved area, in this embodiment, under the condition that the distance between adjacent golden fingers and the number of golden fingers are not increased, by the arrangement of the concave-convex structure 3, the distance between the adjacent first golden finger 10 and the adjacent second golden finger 20 is increased, and the risk of short circuit caused by water vapor in the reliability process is reduced, so that the abnormal display defect of the screen can be improved.

Referring to fig. 2, due to the arrangement of the concave-convex structure 3, the distance between the first gold finger 10 and the second gold finger 20 is increased to the distance between the first gold finger 10 and the third gold finger (the gold finger on the side of the second gold finger 20 far away from the first gold finger 10), and under the condition that water vapor cannot be absolutely isolated, the risk of short circuit is reduced, so that poor display caused by short circuit can be improved.

In this embodiment, the non-windowing region 2 includes a first region and a second region that are adjacently disposed, the protrusion 31 is formed by extending the first region in a direction approaching the windowing region 1, and/or the recess 32 is formed by recessing the second region in a direction away from the windowing region 1.

The first region extends to form a protrusion 31 in a direction close to the windowing region 1, a recess 32 is naturally formed in the second region adjacent to the protrusion 31 relative to the protrusion 31, similarly, the second region is recessed 32 in a direction away from the windowing region 1 to form a recess 32, and the first region adjacent to the recess 32 is formed to form a protrusion 31 relative to the recess 32. In some embodiments, in order to increase the distance between the center point of the protrusion 31 and the center point of the recess 32 in the first direction, the first region extends to form the protrusion 31 in a direction close to the window opening region 1, and the second region recesses 32 to form the recess 32 in a direction away from the window opening region 1.

In the present embodiment, the concave-convex structure 3 is formed when the protective layer is cut to form the window opening region 1.

In the present embodiment, the shape of the cross section of the concave-convex structure 3 in the direction parallel to the substrate layer 101 is a wave shape.

The cross-sectional shape of the concave-convex structure 3 is not limited to the above-mentioned wave shape, and may be, for example, a saw-tooth shape, and the cross-sectional shape of the protrusion 31 or the recess 32 may be, but not limited to, an arc shape, an isosceles trapezoid shape, or a triangle shape.

In the extending direction of the first gold finger 10, the distance between the wave-shaped peaks and the wave-shaped troughs may be set according to actual needs, and in this embodiment, the distance between the wave-shaped peaks and the wave-shaped troughs in the extending direction of the first gold finger 10 is, for example, 50 to 70um, but not limited thereto.

It should be noted that, in some embodiments, the windowing region 1 may be located at one end of the flexible circuit board, at this time, the flexible circuit board is divided into the windowing region 1 and the non-windowing region 2 along the first direction, and the concave-convex structure 3 is located at one end of the non-windowing region 2 close to the windowing region 1, as shown in fig. 2. In some embodiments, the windowing region 1 is located in the middle of the flexible printed circuit board, that is, along the first direction, two opposite sides of the windowing region 1 are both non-windowing regions 2, and at this time, along the first direction, one end of each non-windowing region 2, which is close to the windowing region 1, is provided with the concave-convex structure 3, referring to fig. 3.

Referring to fig. 4, in this embodiment, the blocking structure includes a dummy gold finger 30 disposed between the first gold finger 10 and the second gold finger 20, and the dummy gold finger 30 is disposed in parallel with the first gold finger 10.

The number of the gold fingers is sacrificed due to the arrangement of the virtual gold fingers 30, and by additionally arranging the virtual gold fingers 30 between the first gold finger 10 and the second gold finger 20 (the virtual gold fingers 30 do not transmit signals), the distance between the first gold finger 10 and the second gold finger 20 is increased, and the risk of electrochemical corrosion between the first gold finger 10 and the second gold finger 20 is reduced.

In this embodiment, the dummy gold finger 30, the first gold finger 10, and the second gold finger 20 are formed by a synchronous process, which simplifies the process.

There is a gap between the dummy gold finger 30 and the first gold finger 10, a gap between the dummy gold finger 30 and the second gold finger 20, and in some embodiments, the dummy gold finger 30, the first gold finger 10, the second gold finger 20 and the rest of the gold fingers in the windowing area 1 are uniformly distributed, which facilitates the layout.

In the present embodiment, a green oil protection layer 100 is disposed between the non-windowed area 2 and the windowed area 1. The green oil protective layer 100 prevents moisture erosion.

In this embodiment, the conductive layer is made of copper, for example.

In this embodiment, the protection layer includes a covering film layer covering the conductive layer, and an electromagnetic shielding film layer disposed on a side of the covering film layer away from the conductive layer.

It should be noted that the flexible printed circuit board may be a single-layer circuit board or a double-layer circuit board, and fig. 1 shows a double-layer circuit board, a first conductive layer 102, a first covering film layer 103, and a first electromagnetic shielding film layer 104 are sequentially disposed on a first surface of the substrate layer 101, and the first covering film layer 102 and the first conductive layer 103 are connected by a glue layer 200. The second face of the substrate layer 101 is sequentially provided with a second conductive layer 202, a second covering film layer 203 and a second electromagnetic shielding film layer 204, and the second covering film layer 204 is connected with the second conductive layer 202 through a glue layer 200.

It should be noted that the window area may be disposed on one side of the flexible printed circuit board, or both of the two opposite sides of the flexible printed circuit board, and the blocking structures are disposed on both of the two opposite sides of the flexible printed circuit board when both of the two opposite sides of the flexible printed circuit board are disposed.

The following points need to be explained:

(1) the drawings of the embodiments of the disclosure only relate to the structures related to the embodiments of the disclosure, and other structures can refer to general designs.

(2) For purposes of clarity, the thickness of layers or regions in the figures used to describe embodiments of the present disclosure are exaggerated or reduced, i.e., the figures are not drawn on a true scale. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "under" another element, it can be "directly on" or "under" the other element or intervening elements may be present.

(3) Without conflict, embodiments of the present disclosure and features of the embodiments may be combined with each other to arrive at new embodiments.

It will be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principles of the present invention, and the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and scope of the utility model, and such modifications and improvements are also considered to be within the scope of the utility model.

Claims

1. The utility model provides a flexible circuit board, its characterized in that, is including windowing and distinguishing, non-windowing, and be located the first golden finger and the second golden finger in windowing and distinguishing, first golden finger with the parallel and adjacent setting of second golden finger, just first golden finger with pressure differential between the second golden finger is greater than zero, flexible circuit board still includes and blocks the structure, in order to increase first golden finger with the second golden finger is close to the interval of the one end in non-windowing.

2. The flexible circuit board according to claim 1, comprising a substrate layer, a conductive layer and a protective layer which are sequentially stacked, wherein the protective layer covers a part of the conductive layer to form the windowed area and the non-windowed area;

3. The flexible circuit board of claim 2, wherein the non-windowed area comprises a first area and a second area which are adjacently arranged, the protrusion is formed by extending the first area to a direction close to the windowed area, and/or the recess is formed by recessing the second area to a direction far away from the windowed area.

4. The flexible circuit board of claim 2, wherein the relief structure is formed when the protective layer is cut to form the windowed area.

5. The flexible circuit board according to claim 2, wherein a cross section of the concave-convex structure in a direction parallel to the substrate layer has a wave shape.

6. The flexible circuit board of claim 5, wherein the distance between the center points of the adjacent wave-shaped wave crests and wave troughs is 50-70um in the extending direction of the first gold finger.

7. The flexible circuit board of claim 1, wherein the blocking structure comprises a dummy gold finger disposed between the first gold finger and the second gold finger, the dummy gold finger being disposed parallel to the first gold finger.

8. The flexible circuit board of claim 1, wherein a green oil protective layer is disposed between the non-windowed area and the windowed area.

9. The flexible circuit board of claim 2, wherein the conductive layer is made of copper.

10. The flexible circuit board of claim 2, wherein the protective layer comprises a cover film layer covering the conductive layer, and an electromagnetic shielding film layer disposed on a side of the cover film layer away from the conductive layer.