A flexible circuit board and its manufacturing method, and a display device

Abstract

The present invention provides a flexible circuit board and a manufacturing method thereof, and a display device, and relates to the field of display technology. The present invention arranges a routing layer on a flexible substrate, and further arranges a reinforcement layer on a side of the flexible substrate away from the routing layer. The routing layer includes a plurality of signal routing lines distributed along a first routing area, a second routing area, a third routing area, and a fourth routing area. The reinforcement layer includes a first reinforcement structure located in the second routing area and a second reinforcement structure located in the fourth routing area. By arranging a first reinforcement structure in the second routing area of ​​the flexible substrate and arranging a second reinforcement structure in the fourth routing area of ​​the flexible substrate, the impact resistance of the flexible circuit board is enhanced. Therefore, when the display device is impacted, the flexible circuit board is not prone to tearing, thereby ensuring the normal use of the display device and improving the yield and reliability of the display device.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a flexible circuit board and a manufacturing method thereof, and a display device. Background Art

[0002] In a display device, a flexible printed circuit (FPC) is usually required to achieve circuit connection between a display panel and a printed circuit board (PCB).

[0003] Currently, a flexible circuit board forms signal wiring on the surface of one side of a flexible substrate. When a display device is hit, the flexible circuit board is easily torn, thereby causing the display device to be unable to be used normally. Summary of the invention

[0004] The present invention provides a flexible circuit board and a manufacturing method thereof, and a display device, so as to solve the problem that only signal wiring is formed on a flexible substrate in the prior art, and the flexible circuit board is easily torn when the display device is impacted.

[0005] In order to solve the above problems, the present invention discloses a flexible circuit board, the flexible circuit board includes a flexible substrate, the flexible substrate is divided into a routing area and a first binding area and a second binding area located on both sides of the routing area, the routing area includes a first routing area, a second routing area, a third routing area and a fourth routing area which are sequentially away from the first binding area;

[0006] The flexible circuit board also includes a wiring layer arranged on the flexible substrate and a reinforcement layer arranged on a side of the flexible substrate away from the wiring layer;

[0007] Among them, the routing layer includes multiple signal routing lines distributed along the first routing area, the second routing area, the third routing area and the fourth routing area, and the reinforcement layer includes a first reinforcement structure located in the second routing area and a second reinforcement structure located in the fourth routing area.

[0008] Optionally, the flexible circuit board further includes a third reinforcement structure and a fourth reinforcement structure arranged on the same layer as the signal routing line, the third reinforcement structure is located in the second routing line area, the fourth reinforcement structure is located in the fourth routing line area, and the orthographic projections of the third reinforcement structure and the fourth reinforcement structure on the flexible substrate do not overlap with the orthographic projections of the signal routing line on the flexible substrate;

[0009] The third reinforcement structure is connected to the first reinforcement structure through a first via hole penetrating the flexible substrate, and the fourth reinforcement structure is connected to the second reinforcement structure through a second via hole penetrating the flexible substrate.

[0010] Optionally, the flexible circuit board further includes a fifth reinforcement structure provided on the same layer as the signal routing line, the fifth reinforcement structure is located in the third routing line area, and an orthographic projection of the fifth reinforcement structure on the flexible substrate and an orthographic projection of the signal routing line on the flexible substrate do not overlap with each other;

[0011] Wherein, the fifth reinforcement structure is connected to the third reinforcement structure and the fourth reinforcement structure respectively.

[0012] Optionally, the routing layer further includes a ground routing located in the first routing area, and the ground routing is connected to the third reinforcement structure;

[0013] Wherein, materials of the first reinforcement structure, the second reinforcement structure, the third reinforcement structure, the fourth reinforcement structure and the fifth reinforcement structure are all conductive materials.

[0014] Optionally, the first reinforcement structure and the second reinforcement structure are both mesh structures.

[0015] Optionally, the flexible circuit board further includes a plurality of first gold fingers and a plurality of second gold fingers arranged in the same layer as the signal routing line, the first gold fingers are located in the first binding area, the second gold fingers are located in the second binding area, and the signal routing line is connected to the first gold fingers and the second gold fingers respectively;

[0016] Wherein, the distance between the second reinforcement structure and the second gold finger is greater than or equal to 0.2 mm.

[0017] Optionally, the first binding area is an area where the flexible circuit board is bound to the display panel, and the second binding area is an area where the flexible circuit board is bound to a printed circuit board.

[0018] In order to solve the above problems, the present invention also discloses a method for manufacturing a flexible circuit board, comprising:

[0019] A flexible substrate is provided; the flexible substrate is divided into a routing area and a first binding area and a second binding area located on both sides of the routing area, the routing area includes a first routing area, a second routing area, a third routing area and a fourth routing area which are sequentially away from the first binding area;

[0020] A routing layer is formed on the flexible substrate; the routing layer includes a plurality of signal routing lines distributed along the first routing area, the second routing area, the third routing area, and the fourth routing area;

[0021] A reinforcement layer is formed on a side of the flexible substrate away from the routing layer; the reinforcement layer includes a first reinforcement structure located in the second routing area and a second reinforcement structure located in the fourth routing area.

[0022] In order to solve the above problem, the present invention further discloses a display device, including a display panel, a printed circuit board and the above-mentioned flexible circuit board, wherein the flexible circuit board is respectively bound to the display panel and the printed circuit board.

[0023] Optionally, the display device further comprises a cover plate and a backlight module, wherein the cover plate covers the light emitting surface of the display panel, and the backlight module is located on a side of the display panel away from the cover plate;

[0024] Among them, the backlight module includes a plastic frame, and the plastic frame is provided with an adhesive structure and a buffer structure on the same layer on the plastic frame surface arranged opposite to the cover plate. The adhesive structure is respectively bonded to the plastic frame and the cover plate, and the buffer structure is located at the corner position of the plastic frame surface.

[0025] Optionally, the buffer structure has a recessed portion on a surface facing the adhesive structure, and the adhesive structure has a raised portion on a surface facing the buffer structure, and the raised portion is embedded in the recessed portion.

[0026] Optionally, in the direction in which the buffer structure points to the adhesive structure in contact with the buffer structure, the length of the buffer structure is 15 mm to 30 mm.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] The flexible substrate is divided into a routing area and a first binding area and a second binding area located on both sides of the routing area. The routing area includes a first routing area, a second routing area, a third routing area and a fourth routing area which are sequentially away from the first binding area. A routing layer is arranged on the flexible substrate, and a reinforcement layer is also arranged on the side of the flexible substrate away from the routing layer. The routing layer includes a plurality of signal routing lines distributed along the first routing area, the second routing area, the third routing area and the fourth routing area. The reinforcement layer includes a first reinforcement structure located in the second routing area and a second reinforcement structure located in the fourth routing area. The impact resistance of the flexible circuit board is enhanced by arranging the first reinforcement structure in the second routing area of ​​the flexible substrate and arranging the second reinforcement structure in the fourth routing area of ​​the flexible substrate. Therefore, when the display device is impacted, the flexible circuit board is not easy to tear, thereby ensuring the normal use of the display device and improving the yield and reliability of the display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic structural diagram of a first surface of a flexible circuit board according to an embodiment of the present invention is shown;

[0030] Figure 2 A schematic diagram showing the structure of the second surface of the flexible circuit board according to an embodiment of the present invention is shown;

[0031] Figure 3 A schematic structural diagram of a first surface of another flexible circuit board according to an embodiment of the present invention is shown;

[0032] Figure 4 Shown along Figure 3 A cross-sectional view of section AA' in the flexible circuit board shown;

[0033] Figure 5 Shown along Figure 3 A cross-sectional view of section BB' in the flexible circuit board shown;

[0034] Figure 6 A flow chart showing a method for manufacturing a flexible circuit board according to an embodiment of the present invention;

[0035] Figure 7 A schematic diagram showing the structure of a flexible circuit board after being bound to a display panel and a printed circuit board according to an embodiment of the present invention;

[0036] Figure 8 The schematic diagram shows the structure of the bonding structure and the buffer structure on the surface of the rubber frame in the embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Embodiment 1

[0039] Reference Figure 1 , showing a schematic structural diagram of a first surface of a flexible circuit board according to an embodiment of the present invention, Figure 2 A schematic structural diagram of the second surface of the flexible circuit board according to an embodiment of the present invention is shown.

[0040] An embodiment of the present invention provides a flexible circuit board, which includes a flexible substrate 10, wherein the flexible substrate 10 is divided into a routing area and a first binding area 11 and a second binding area 12 located on both sides of the routing area, wherein the routing area includes a first routing area 13, a second routing area 14, a third routing area 15 and a fourth routing area 16 which are sequentially away from the first binding area 11; the flexible circuit board also includes a routing layer arranged on the flexible substrate 10 and a reinforcement layer 30 arranged on a side of the flexible substrate 10 away from the routing layer; wherein the routing layer includes a plurality of signal routing lines 21 distributed along the first routing area 13, the second routing area 14, the third routing area 15 and the fourth routing area 16, and the reinforcement layer 30 includes a first reinforcement structure 31 located in the second routing area 14 and a second reinforcement structure 32 located in the fourth routing area 16.

[0041] In actual products, the material of the flexible substrate 10 can be PI (Polyimide) or PET (Polyethylene terephthalate), etc. According to the fixing method and fixed position of the flexible circuit board in the display device, the flexible circuit board is divided into a routing area and a first binding area 11 and a second binding area 12 located on both sides of the routing area, that is, the routing area is located between the first binding area 11 and the second binding area 12.

[0042] Among them, the routing area includes a first routing area 13, a second routing area 14, a third routing area 15 and a fourth routing area 16 which are successively away from the first binding area 11. That is to say, the first routing area 13 is located on the side of the first binding area 11 facing the second binding area 12, the second routing area 14 is located on the side of the first routing area 13 facing the second binding area 12, the third routing area 15 is located on the side of the second routing area 14 facing the second binding area 12, and the fourth routing area 16 is located between the third routing area 15 and the second binding area 12.

[0043] In order to realize the circuit connection between the display panel and the printed circuit board, it is necessary to form a plurality of signal traces 21 on the flexible substrate 10, and the signal traces 21 are distributed along the first trace area 13, the second trace area 14, the third trace area 15 and the fourth trace area 16. Specifically, the signal traces 21 are respectively connected to the display panel and the printed circuit board, and the drive signal and other signals provided by the printed circuit board for driving the display panel to display are transmitted to the display panel through the signal traces 21, thereby driving the display panel to display.

[0044] Specifically, the first binding area 11 is an area where the flexible circuit board is bound to the display panel, and the second binding area 12 is an area where the flexible circuit board is bound to the printed circuit board.

[0045] In a display device, such as a vehicle-mounted display device, after the display panel and the printed circuit board are bound by the flexible circuit board, it is necessary to firstly attach the cover plate to the display panel to obtain a display module, then fix the display module to the backlight module, and finally, by bending the flexible circuit board, fix the printed circuit board to the side of the backlight module away from the display panel. At this time, the flexible circuit board is in a bent state, the first wiring area 13 and the third wiring area 15 are bending areas, and the second wiring area 14 and the fourth wiring area 16 are areas where the flexible circuit board is susceptible to collision.

[0046] In order to ensure that the flexible circuit board will not tear when it is hit, it is necessary to enhance the strength of the second wiring area 14 and the fourth wiring area 16 in the flexible circuit board. Therefore, a reinforcement layer 30 is formed on the side of the flexible substrate 10 away from the wiring layer. The reinforcement layer 30 includes a first reinforcement structure 31 located in the second wiring area 14 and a second reinforcement structure 32 located in the fourth wiring area 16. That is, on the surface of the flexible substrate 10 away from the signal wiring 21, the first reinforcement structure 31 is formed in the second wiring area 14, and the second reinforcement structure 32 is formed in the fourth wiring area 16. The strength of the second wiring area 14 is enhanced based on the first reinforcement structure 31, and the strength of the fourth wiring area 16 is enhanced based on the second reinforcement structure 32, thereby improving the impact resistance of the flexible circuit board. Therefore, during the use or testing of the display device, if the display device is hit, the flexible circuit board is not easy to tear, thereby ensuring the normal use of the display device.

[0047] Furthermore, in the related art, after the signal routing is formed on the surface of the flexible substrate, a copper layer is also provided on the entire surface of the flexible substrate away from the signal routing to improve the impact resistance of the flexible circuit board. However, after the display panel and the printed circuit board are bound by the flexible circuit board, the cover plate is first bonded to the display panel, and then the backlight module and the printed circuit board are assembled and fixed. Therefore, during the bonding process of the cover plate and the assembly process of the backlight module, the printed circuit board will always be in an active state. In the flexible circuit board, the first routing area close to the first binding area bound to the display panel will be bent frequently. Since the strength of the first routing area is relatively high, uninterrupted stress will be applied to the first binding area, which particularly tests the operator's operating skills. When the operation is slightly inappropriate, some gold fingers in the first binding area of ​​the flexible circuit board will be broken. In the embodiment of the present invention, reinforcement structures are only provided in the second wiring area 14 and the fourth wiring area 16 of the flexible substrate 10 to improve the impact resistance of the flexible circuit board, and in the first wiring area 13 close to the first binding area 11, only the signal wiring 21 is provided without the reinforcement structure, thereby reducing the conduction of the bending stress to the first binding area 11, reducing the risk of the gold finger in the first binding area 11 of the flexible circuit board breaking, and reducing the requirements on the operating techniques of the operator during the lamination process of the cover plate and the assembly process of the backlight module; and, only the signal wiring 21 is provided in the first wiring area 12, which can also improve the bending resistance of the flexible circuit board.

[0048] It should be noted that the first reinforcement structure 31 is distributed in various areas of the second wiring area 14, and the second reinforcement structure 32 is distributed in various areas of the fourth wiring area 16;

[0049] Further, such as Figure 3 and Figure 4 As shown, the flexible circuit board also includes a third reinforcement structure 22 and a fourth reinforcement structure 23 arranged on the same layer as the signal wiring 21, the third reinforcement structure 22 is located in the second wiring area 14, and the fourth reinforcement structure 23 is located in the fourth wiring area 16, and the orthographic projections of the third reinforcement structure 22 and the fourth reinforcement structure 23 on the flexible substrate 10 do not have an overlapping area with the orthographic projection of the signal wiring 21 on the flexible substrate 10; wherein the third reinforcement structure 22 is connected to the first reinforcement structure 31 through a first via hole 221 penetrating the flexible substrate 10, and the fourth reinforcement structure 23 is connected to the second reinforcement structure 32 through a second via hole 231 penetrating the flexible substrate 10.

[0050] In order to further improve the impact resistance of the flexible circuit board, a third reinforcement structure 22 and a fourth reinforcement structure 23 may be formed on the side of the flexible substrate 10 away from the reinforcement layer 30, that is, the third reinforcement structure 22 and the fourth reinforcement structure 23 are arranged on the same layer as the signal wiring 21, and the third reinforcement structure 22 is located in the second wiring area 14, and the fourth reinforcement structure 23 is located in the fourth wiring area 16. Therefore, the strength of the second wiring area 14 can be further enhanced by the third reinforcement structure 22, and the strength of the fourth wiring area 16 can be further enhanced based on the fourth reinforcement structure 23, thereby further improving the impact resistance of the flexible circuit board.

[0051] In actual products, in order to avoid the influence of the third reinforcement structure 22 and the fourth reinforcement structure 23 on the signal transmitted by the signal wiring 21, it is necessary to reasonably set the positions of the third reinforcement structure 22, the fourth reinforcement structure 23 and the signal wiring 21 on the flexible substrate 10, so that there is no overlapping area between the orthographic projection of the third reinforcement structure 22 and the fourth reinforcement structure 23 on the flexible substrate 10 and the orthographic projection of the signal wiring 21 on the flexible substrate 10, that is, the third reinforcement structure 22 and the fourth reinforcement structure 23 are not in contact with the signal wiring 21.

[0052] In addition, the third reinforcement structure 22 is connected to the first reinforcement structure 31 through the first via 221 penetrating the flexible substrate 10, that is, in the second wiring area 14, the third reinforcement structure 22 and the first reinforcement structure 31 located on both sides of the flexible substrate 10 are connected. Of course, the fourth reinforcement structure 23 is also connected to the second reinforcement structure 32 through the second via 231 penetrating the flexible substrate 10, that is, in the fourth wiring area 16, the fourth reinforcement structure 23 and the second reinforcement structure 32 located on both sides of the flexible substrate 10 are connected.

[0053] Further, such as Figure 3 and Figure 5 As shown, the flexible circuit board also includes a fifth reinforcement structure 24 arranged on the same layer as the signal wiring 21, the fifth reinforcement structure 24 is located in the third wiring area 15, and the orthographic projection of the fifth reinforcement structure 24 on the flexible substrate 10 and the orthographic projection of the signal wiring 21 on the flexible substrate 10 do not have an overlapping area; wherein the fifth reinforcement structure 24 is respectively connected to the third reinforcement structure 22 and the fourth reinforcement structure 23.

[0054] In order to ensure the bending performance of the third wiring area 15 in the flexible circuit board and further improve the impact resistance of the third wiring area 15, a fifth reinforcement structure 24 can be formed on the side of the flexible substrate 10 away from the reinforcement layer 30, that is, the fifth reinforcement structure 24 is arranged on the same layer as the signal wiring 21, and the fifth reinforcement structure 24 is located in the third wiring area 15. Therefore, the strength of the third wiring area 15 is improved by the fifth reinforcement structure 24, thereby further improving the impact resistance of the flexible circuit board.

[0055] In actual products, in order to avoid the influence of the fifth reinforcement structure 24 on the signal transmitted by the signal wiring 21, it is necessary to reasonably set the positions of the fifth reinforcement structure 24 and the signal wiring 21 on the flexible substrate 10, so that there is no overlapping area between the orthographic projection of the fifth reinforcement structure 24 on the flexible substrate 10 and the orthographic projection of the signal wiring 21 on the flexible substrate 10, that is, the fifth reinforcement structure 24 does not contact the signal wiring 21.

[0056] In addition, the fifth reinforcing structure 24 is respectively connected to the third reinforcing structure 22 and the fourth reinforcing structure 23. Therefore, the third reinforcing structure 22 is connected to the first reinforcing structure 31 through the first via 221, the third reinforcing structure 22 is also connected to the fifth reinforcing structure 24, the fifth reinforcing structure 24 is further connected to the fourth reinforcing structure 23, and the fourth reinforcing structure 23 is further connected to the second reinforcing structure 32 through the second via 231.

[0057] It should be noted that the third reinforcement structure 22 , the fourth reinforcement structure 23 and the fifth reinforcement structure 24 can be respectively set on the left and right sides of all signal lines 21 , and can also be set between any two adjacent signal lines 21 .

[0058] Further, such as Figure 3 As shown, the routing layer also includes a ground routing 25 located in the first routing area 13, and the ground routing 25 is connected to the third reinforcement structure 22; wherein the materials of the first reinforcement structure 31, the second reinforcement structure 32, the third reinforcement structure 22, the fourth reinforcement structure 23 and the fifth reinforcement structure 24 are all conductive materials.

[0059] In order to meet the requirements of the display device for ESD (Electro-Static discharge) and EMC (ElectroMagnetic Compatibility), it is also necessary to form a grounding trace 25 on the side of the flexible substrate 10 away from the reinforcing layer 30, that is, the grounding trace 25 is arranged on the same layer as the signal trace 21, and the grounding trace 25 is located in the first trace area 13. Specifically, the grounding traces 25 can be arranged on both sides of all signal traces 21, that is, the grounding traces 25 are arranged on the left side of all signal traces 21, and the grounding traces 25 are also arranged on the right side of all signal traces 21.

[0060] In actual products, the first reinforcement structure 31, the second reinforcement structure 32, the third reinforcement structure 22, the fourth reinforcement structure 23 and the fifth reinforcement structure 24 can be made of conductive materials; and the grounding line 25 is connected to the third reinforcement structure 22, and the third reinforcement structure 22 is respectively connected to the first reinforcement structure 31 and the fifth reinforcement structure 24, the fifth reinforcement structure 24 is further connected to the fourth reinforcement structure 23, and the fourth reinforcement structure 23 is also connected to the second reinforcement structure 32. Therefore, through the grounding lines 25 on the left and right sides and the mutual connection between each reinforcement structure, a grounding loop around all signal lines 21 can be formed, and the common ground effect is enhanced through the grounding loop, and the anti-ESD capability and EMC capability are improved.

[0061] The conductive materials used in the first reinforcement structure 31, the second reinforcement structure 32, the third reinforcement structure 22, the fourth reinforcement structure 23 and the fifth reinforcement structure 24 are metal materials, such as copper, etc. Moreover, the signal trace 21, the ground trace 25, the first reinforcement structure 31, the second reinforcement structure 32, the third reinforcement structure 22, the fourth reinforcement structure 23 and the fifth reinforcement structure 24 are all made of the same material.

[0062] In the embodiment of the present invention, both the first reinforcement structure 31 and the second reinforcement structure 32 are mesh structures.

[0063] The first reinforcement structure 31 includes a plurality of mutually parallel first metal traces and a plurality of mutually parallel second metal traces, and the first metal traces and the second metal traces are arranged crosswise, such as the first metal traces and the second metal traces are perpendicular to each other, and the first reinforcement structure 31 can be distributed in a mesh shape by the crossed first metal traces and the second metal traces. When the first reinforcement structure 31 is distributed in a mesh shape, the first reinforcement structure 31 can enhance the strength of the second trace area 14 while ensuring the bending toughness of the flexible circuit board at the second trace area 14 and the smooth transition of the flexibility of the flexible circuit board at the first trace area 13, so that during the bonding process of the cover plate and the assembly process of the backlight module, no relatively large stress is transmitted to the first binding area 11.

[0064] Correspondingly, the second reinforcement structure 32 also includes a plurality of third metal traces parallel to each other and a plurality of fourth metal traces parallel to each other, and the third metal traces and the fourth metal traces are arranged crosswise, such as the third metal traces and the fourth metal traces are perpendicular to each other, and the second reinforcement structure 32 can also be distributed in a mesh shape through the crosswise third metal traces and the fourth metal traces. When the second reinforcement structure 32 is distributed in a mesh shape, the second reinforcement structure 32 can enhance the strength of the fourth trace area 16 while ensuring the bending toughness of the flexible circuit board at the fourth trace area 16, so that during the laminating process of the cover plate and the assembly process of the backlight module, no relatively large stress is transmitted to the second binding area 12.

[0065] Of course, the third reinforcing structure 22, the fourth reinforcing structure 23 and the fifth reinforcing structure 24 may also be mesh structures.

[0066] In an embodiment of the present invention, the flexible circuit board also includes a plurality of first gold fingers 26 and a plurality of second gold fingers 27 arranged on the same layer as the signal routing line 21, the first gold fingers 26 are located in the first binding area 11, the second gold fingers 27 are located in the second binding area 12, and the signal routing line 21 is connected to the first gold fingers 26 and the second gold fingers 27 respectively; wherein, the distance between the second reinforcement structure 32 and the second gold fingers 27 is greater than or equal to 0.2 mm.

[0067] A plurality of first gold fingers 26 are arranged in the first binding area 11 of the flexible substrate 10, and the first gold fingers 26 are arranged in the same layer as the signal wiring 21 and are connected to each other, and a plurality of second gold fingers 27 are arranged in the second binding area 12 of the flexible substrate 10, and the second gold fingers 27 are arranged in the same layer as the signal wiring 21 and are connected to each other. After the flexible circuit board is bound to the display panel and the printed circuit board, the first gold fingers 26 are connected to the pins in the display panel, and the second gold fingers 27 are connected to the pins in the printed circuit board, so that the circuit connection between the display panel and the printed circuit board is realized through the flexible circuit board.

[0068] Furthermore, the distance between the second reinforcement structure 32 and the second gold finger 27 is greater than or equal to 0.2 mm, such as 0.3 mm, 0.4 mm, etc. By setting the distance between the second reinforcement structure 32 and the second gold finger 27 to be greater than or equal to 0.2 mm, during the lamination process of the cover plate and the assembly process of the backlight module, the distance between the second reinforcement structure 32 and the second gold finger 27 is prevented from being too close, thereby preventing the second gold finger 27 from being broken due to stress.

[0069] It should be noted that the distance between the second reinforcement structure 32 and the second gold finger 27 refers to the spacing distance between the second reinforcement structure 32 and the second gold finger 27 in the direction from the first binding area 11 to the second binding area 12 .

[0070] When the fourth wiring area 16 is further provided with a fourth reinforcement structure 23 , the distance between the fourth reinforcement structure 23 and the second gold finger 27 is also greater than or equal to 0.2 mm.

[0071] In addition, a grounding gold finger is disposed in the first binding area 11 of the flexible substrate 10. The grounding gold finger is disposed in the same layer as the first gold finger 26 and is connected to the grounding trace 25 in the first trace area 13 to achieve a grounding function.

[0072] In the embodiment of the present invention, the first reinforcement structure is provided in the second wiring area of ​​the flexible substrate, and the second reinforcement structure is provided in the fourth wiring area of ​​the flexible substrate to enhance the impact resistance of the flexible circuit board. Therefore, when the display device is impacted, the flexible circuit board is not easily torn, thereby ensuring the normal use of the display device and improving the yield and reliability of the display device.

[0073] Embodiment 2

[0074] Reference Figure 6 , shows a flow chart of a method for manufacturing a flexible circuit board according to an embodiment of the present invention, which may specifically include the following steps:

[0075] Step 601, providing a flexible substrate; the flexible substrate is divided into a routing area and a first binding area and a second binding area located on both sides of the routing area, and the routing area includes a first routing area, a second routing area, a third routing area and a fourth routing area which are sequentially away from the first binding area.

[0076] In an embodiment of the present invention, first, a flexible substrate 10 is provided, and according to the fixing method and fixing position of the flexible circuit board in the display device, the flexible circuit board is divided into a routing area and a first binding area 11 and a second binding area 12 located on both sides of the routing area, and the routing area includes a first routing area 13, a second routing area 14, a third routing area 15 and a fourth routing area 16 which are sequentially away from the first binding area 11.

[0077] Step 602 , forming a routing layer on the flexible substrate; the routing layer includes a plurality of signal routing lines distributed along the first routing area, the second routing area, the third routing area, and the fourth routing area.

[0078] In the embodiment of the present invention, after the flexible substrate 10 is obtained, a plurality of signal traces 21 are formed on one side of the flexible substrate 10 by using a patterning process. The signal traces 21 are distributed along the first trace area 13, the second trace area 14, the third trace area 15 and the fourth trace area 16, that is, each signal trace 21 extends from the first trace area 13 to the fourth trace area 16.

[0079] When the third reinforcement structure 22, the fourth reinforcement structure 23, the fifth reinforcement structure 24 and the ground trace 25 are further provided on the flexible substrate 10, and the third reinforcement structure 22, the fourth reinforcement structure 23, the fifth reinforcement structure 24, the ground trace 25 and the signal trace 21 are made of the same material, the third reinforcement structure 22, the fourth reinforcement structure 23, the fifth reinforcement structure 24, the ground trace 25 and the signal trace 21 are formed simultaneously using the same patterning process.

[0080] Specifically, a metal film layer is deposited on the flexible substrate 10, a photoresist is coated on the metal film layer, and the photoresist is exposed using a mask. After the exposure is completed, the photoresist is developed to remove the photoresist in a partial area, and then the metal film layer in the photoresist removal area is etched, and finally the remaining photoresist is stripped off to produce the signal wiring 21, the third reinforcement structure 22, the fourth reinforcement structure 23, the fifth reinforcement structure 24 and the ground wiring 25.

[0081] Step 603 , forming a reinforcement layer on a side of the flexible substrate away from the routing layer; the reinforcement layer includes a first reinforcement structure located in the second routing area and a second reinforcement structure located in the fourth routing area.

[0082] In the embodiment of the present invention, after the flexible substrate 10 is obtained, a reinforcement layer 30 is formed on a side of the flexible substrate 10 away from the routing layer. The reinforcement layer 30 includes a first reinforcement structure 31 located in the second routing area 14 and a second reinforcement structure 32 located in the fourth routing area 16 .

[0083] The first reinforcement structure 31 and the second reinforcement structure 32 are made of metal materials, which can also be formed on a side of the flexible substrate 10 away from the wiring layer by using a patterning process.

[0084] It should be noted that there is no fixed order between step 602 and step 603. The signal trace 21 may be formed on the flexible substrate 10 first and then the first reinforcement structure 31 and the second reinforcement structure 32 are formed. Alternatively, the first reinforcement structure 31 and the second reinforcement structure 32 may be formed first and then the signal trace 21 is formed. The embodiment of the present invention does not limit this.

[0085] In the embodiment of the present invention, the first reinforcement structure is provided in the second wiring area of ​​the flexible substrate, and the second reinforcement structure is provided in the fourth wiring area of ​​the flexible substrate to enhance the impact resistance of the flexible circuit board. Therefore, when the display device is impacted, the flexible circuit board is not easily torn, thereby ensuring the normal use of the display device and improving the yield and reliability of the display device.

[0086] Embodiment 3

[0087] An embodiment of the present invention provides a display device, such as Figure 7 As shown, it includes a display panel 71, a printed circuit board 72 and the above-mentioned flexible circuit board 73, and the flexible circuit board 73 is bound to the display panel 71 and the printed circuit board 72 respectively.

[0088] The display panel 71 is bound to the first gold finger 26 in the first binding area 11 of the flexible circuit board 73 , and the printed circuit board 72 is bound to the second gold finger 27 in the second binding area 12 of the flexible circuit board 73 .

[0089] For the detailed description of the flexible circuit board 73 , reference may be made to the description of the above-mentioned first and second embodiments, which will not be repeated here.

[0090] In addition, the display device further includes a cover plate and a backlight module. The cover plate covers the light emitting surface of the display panel 71, and the backlight module is located on a side of the display panel 71 away from the cover plate. Figure 8 As shown, the backlight module includes a plastic frame 80, and a bonding structure 81 and a buffer structure 82 are arranged on the same layer on the plastic frame surface arranged opposite to the cover plate. The bonding structure 81 is bonded to the plastic frame 80 and the cover plate respectively, and the buffer structure 82 is located at the corner position of the plastic frame surface.

[0091] In actual products, a cover plate is provided on the light-emitting surface of the display panel to protect the display panel and other structures, and a backlight module is provided on the opposite side of the light-emitting surface of the display panel. The backlight module includes structures such as optical film materials, a back plate and a rubber frame.

[0092] In the actual assembly process, the display panel 71 and the printed circuit board 72 are first bound by the flexible circuit board 73, and then the bound display panel and the cover plate are glued by OCR (Optical Clear Resin) to obtain a display module, and finally the display module and the backlight module are fixed together.

[0093] In the related art, a circle of double-sided tape is pasted on the surface of a rubber frame arranged opposite to the cover plate, and the display module and the backlight module are fixed by the double-sided tape. However, since the surface of the rubber frame and the surface of the cover plate are not absolutely flat, they themselves will have certain deformation. When the surface of the rubber frame and the surface of the cover plate are fixed by the double-sided tape, local uneven force will occur, causing local force on the cover plate. The stress on the cover plate is transmitted to the display panel through the OCR tape. Then, the display panel will cause the liquid crystal box to deform under the influence of external force, so that the box thickness of the liquid crystal box and the arrangement of liquid crystal molecules will change, and then cause the light that originally needs to be blocked to be emitted from the light-emitting surface of the display panel, resulting in more serious light leakage. Usually, the corners of the display panel are more sensitive to force. Therefore, light leakage usually occurs at the corners of the display panel.

[0094] Therefore, in order to improve the light leakage problem of the display panel, an embodiment of the present invention sets an adhesive structure 81 and a buffer structure 82 on the surface of the glue frame arranged opposite to the cover plate. The adhesive structure 81 and the buffer structure 82 are arranged in the same layer, and the display module and the backlight module are fixed by the adhesive structure 81, and the buffer structure 82 is located at the corners of the glue frame surface, that is, at the four corners of the glue frame surface, the original double-sided tape is replaced by the buffer structure 82. The buffer structure 82 is used to absorb partial deformation of the glue frame surface and the cover plate surface, thereby improving the stress condition of the corners of the cover plate, and correspondingly, reducing the external force transmitted from the cover plate to the display panel through the OCR glue, reducing or avoiding the deformation of the liquid crystal box, and thus improving the light leakage phenomenon of the display panel.

[0095] Specifically, the surface of the rubber frame includes a first surface, a second surface, a third surface and a fourth surface connected end to end in sequence, the first surface and the third surface are arranged in parallel, the second surface and the fourth surface are arranged in parallel, and the first surface and the second surface are perpendicular to each other. The four corner positions of the surface of the rubber frame refer to: the position of the first surface close to the second surface and the position of the second surface close to the first surface, the position of the second surface close to the third surface and the position of the third surface close to the second surface, the position of the third surface close to the fourth surface and the position of the fourth surface close to the third surface, and the position of the fourth surface close to the first surface and the position of the first surface close to the fourth surface.

[0096] The material of the bonding structure 81 is double-sided tape, and the material of the buffer structure 82 is foam.

[0097] Furthermore, the buffer structure 82 has a recessed portion on the surface facing the bonding structure 81 , and the bonding structure 81 has a raised portion on the surface facing the buffer structure 82 , and the raised portion is embedded in the recessed portion.

[0098] That is to say, the surface of the buffer structure 82 facing the bonding structure 81 and the surface of the bonding structure 81 facing the buffer structure 82 are not flat. The surface of the buffer structure 82 facing the bonding structure 81 is distributed in a stepped manner to form a recessed portion, and the surface of the bonding structure 81 facing the buffer structure 82 is also distributed in a stepped manner to form a raised portion. The recessed portion and the raised portion match each other, and when the buffer structure 82 and the bonding structure 81 are set on the surface of the rubber frame, the raised portion is embedded in the recessed portion.

[0099] If the surface of the buffer structure 82 facing the adhesive structure 81 and the surface of the adhesive structure 81 facing the buffer structure 82 are both set to be planes, then when the buffer structure 82 and the adhesive structure 81 are set on the surface of the frame, there will be a gap between the buffer structure 82 and the adhesive structure 81, which will cause dust and other impurities to enter the display device through the gap. Therefore, in the embodiment of the present invention, the surface of the buffer structure 82 facing the adhesive structure 81 is set to a recessed portion, and the surface of the adhesive structure 81 facing the buffer structure 82 is set to a raised portion, and the raised portion is embedded in the recessed portion, so that the contact between the buffer structure 82 and the adhesive structure 81 is closer, thereby reducing the risk of dust entering and improving the dustproof effect of the display device.

[0100] like Figure 8 As shown, in the direction of the buffer structure 82 pointing to the bonding structure 81 in contact with the buffer structure 82, the length L1 of the buffer structure 82 is 15 mm to 30 mm. For example, the length L1 of the buffer structure 82 is 18 mm, 20 mm, 25 mm, etc. Moreover, the lengths of the buffer structures 82 in contact with the bonding structure 81 may be equal or unequal.

[0101] By properly setting the length L1 of each buffer structure 82, the bonding structure 81 can stably fix the display module and the backlight module, while the buffer structure 82 can absorb more partial deformation of the surface of the plastic frame and the cover plate to better improve the light leakage of the display panel.

[0102] In addition, after the backlight module and the display module are fixed, part of the flexible circuit board 73 will be exposed to the outside, such as the third wiring area 15 in the flexible circuit board 73 will be exposed. Therefore, it is necessary to set a tape layer on the exposed flexible circuit board 73 to protect the exposed flexible circuit board 73.

[0103] In the embodiment of the present invention, the first reinforcement structure is provided in the second wiring area of ​​the flexible substrate, and the second reinforcement structure is provided in the fourth wiring area of ​​the flexible substrate to enhance the impact resistance of the flexible circuit board. Therefore, when the display device is impacted, the flexible circuit board is not easily torn, thereby ensuring the normal use of the display device and improving the yield and reliability of the display device.

[0104] For the above-mentioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the order of the actions described, because according to the present invention, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0105] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0106] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0107] The above is a detailed introduction to a flexible circuit board and a manufacturing method thereof, and a display device provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for a person skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A flexible circuit board, characterized in that: The flexible circuit board includes a flexible substrate, the flexible substrate is divided into a routing area and a first binding area and a second binding area located on both sides of the routing area, the routing area includes a first routing area, a second routing area, a third routing area and a fourth routing area which are sequentially away from the first binding area; The flexible circuit board also includes a wiring layer arranged on the flexible substrate and a reinforcement layer arranged on a side of the flexible substrate away from the wiring layer; The routing layer includes a plurality of signal routing lines distributed along the first routing area, the second routing area, the third routing area, and the fourth routing area, and the reinforcement layer includes a first reinforcement structure located in the second routing area and a second reinforcement structure located in the fourth routing area; Wherein, when the flexible circuit board is in a bent state, the first routing area and the third routing area are bending areas.

2. The flexible circuit board according to claim 1, characterized in that: The flexible circuit board further comprises a third reinforcement structure and a fourth reinforcement structure arranged on the same layer as the signal routing line, the third reinforcement structure is located in the second routing line area, the fourth reinforcement structure is located in the fourth routing line area, and the orthographic projections of the third reinforcement structure and the fourth reinforcement structure on the flexible substrate do not overlap with the orthographic projections of the signal routing line on the flexible substrate; The third reinforcement structure is connected to the first reinforcement structure through a first via hole penetrating the flexible substrate, and the fourth reinforcement structure is connected to the second reinforcement structure through a second via hole penetrating the flexible substrate.

3. The flexible circuit board according to claim 2, characterized in that: The flexible circuit board further includes a fifth reinforcement structure provided on the same layer as the signal routing line, the fifth reinforcement structure being located in the third routing line area, and an orthographic projection of the fifth reinforcement structure on the flexible substrate and an orthographic projection of the signal routing line on the flexible substrate having no overlapping area; Wherein, the fifth reinforcement structure is connected to the third reinforcement structure and the fourth reinforcement structure respectively.

4. The flexible circuit board according to claim 3, characterized in that: The routing layer further includes a ground routing located in the first routing area, and the ground routing is connected to the third reinforcement structure; Wherein, materials of the first reinforcement structure, the second reinforcement structure, the third reinforcement structure, the fourth reinforcement structure and the fifth reinforcement structure are all conductive materials.

5. The flexible circuit board according to claim 1, characterized in that: The first reinforcement structure and the second reinforcement structure are both mesh structures.

6. The flexible circuit board according to claim 1, characterized in that: The flexible circuit board further includes a plurality of first gold fingers and a plurality of second gold fingers arranged on the same layer as the signal routing line, the first gold fingers are located in the first binding area, the second gold fingers are located in the second binding area, and the signal routing line is connected to the first gold fingers and the second gold fingers respectively; Wherein, the distance between the second reinforcement structure and the second gold finger is greater than or equal to 0.2 mm.

7. The flexible circuit board according to any one of claims 1 to 6, characterized in that: The first binding area is an area where the flexible circuit board is bound to the display panel, and the second binding area is an area where the flexible circuit board is bound to the printed circuit board.

8. A method for manufacturing a flexible circuit board, characterized in that: include: providing a flexible substrate; The flexible substrate is divided into a routing area and a first binding area and a second binding area located on both sides of the routing area, and the routing area includes a first routing area, a second routing area, a third routing area and a fourth routing area which are sequentially away from the first binding area; A routing layer is formed on the flexible substrate; the routing layer includes a plurality of signal routing lines distributed along the first routing area, the second routing area, the third routing area, and the fourth routing area; A reinforcement layer is formed on a side of the flexible substrate away from the routing layer; the reinforcement layer comprises a first reinforcement structure located in the second routing area and a second reinforcement structure located in the fourth routing area; Wherein, when the flexible circuit board is in a bent state, the first routing area and the third routing area are bending areas.

9. A display device, characterized in that: The invention comprises a display panel, a printed circuit board and a flexible circuit board as claimed in any one of claims 1 to 7, wherein the flexible circuit board is bound to the display panel and the printed circuit board respectively.

10. The display device according to claim 9, characterized in that: The display device further comprises a cover plate and a backlight module, wherein the cover plate covers the light emitting surface of the display panel, and the backlight module is located on a side of the display panel away from the cover plate; Among them, the backlight module includes a plastic frame, and the plastic frame is provided with an adhesive structure and a buffer structure on the same layer on the plastic frame surface arranged opposite to the cover plate. The adhesive structure is respectively bonded to the plastic frame and the cover plate, and the buffer structure is located at the corner position of the plastic frame surface.

11. The display device according to claim 10, characterized in that: The buffer structure has a concave portion on a surface facing the bonding structure, and the bonding structure has a convex portion on a surface facing the buffer structure, and the convex portion is embedded in the concave portion.

12. The display device according to claim 10, characterized in that: In the direction in which the buffer structure points to the adhesive structure in contact with the buffer structure, the length of the buffer structure is 15 mm to 30 mm.

Images