Flexible printed circuit board and display device

Abstract

Embodiments of the present disclosure relate to the technical field of display, and provide a flexible printed circuit board. The flexible printed circuit board comprises a board body, a first shielding layer, a reinforcing sheet, and a connector; the board body has a first surface and a second surface which are opposite to each other; and the board body has a first end and a second end in the length direction of the board body. The connector is located on the first surface and at the first end, and the connector is connected to the board body. The reinforcing sheet is located on the second surface and at the first end, and the orthographic projection of the connector on the first surface at least partially overlaps the orthographic projection of the reinforcing sheet on the first surface. The first shielding layer is located on the second surface, and the first shielding layer is electrically connected to the reinforcing sheet. The embodiments of the present disclosure can ameliorate the problem of poor electrostatic and electromagnetic protection capabilities of the back surface of the connector in the flexible printed circuit board.

Description

Flexible circuit board and display device

[0001] This application claims priority to Chinese patent application No. 202410232186.7, filed on February 29, 2024, entitled “Flexible Circuit Board and Display Device,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The embodiments of the present disclosure relate to the field of display technology, and in particular to a flexible circuit board and a display device. Background Art

[0003] Display devices are widely used in everyday applications, such as in mobile phones, tablet computers, and other electronic devices. Display devices typically include a display panel and a flexible printed circuit board (FPC). The FPC is connected to the display panel and is located on the backside of the display panel.

[0004] In related art, an FPC includes a board, a first shielding layer, a reinforcement sheet, and a connector. The board has a first surface and a second surface facing each other, and a first end and a second end along its length. The connector is located at the first end and on the first surface, and is connected to the board. The reinforcement sheet is located on the second surface and at the first end, with the orthographic projection of the connector on the first surface at least partially overlapping the orthographic projection of the reinforcement sheet on the first surface. The first shielding layer is located on the second surface, and the first shielding layer and the reinforcement sheet are spaced apart.

[0005] During use of the display device, the electrostatic and electromagnetic protection capabilities of the back of the connector are relatively poor. Summary of the Invention

[0006] The present disclosure provides a flexible circuit board and a display device that can improve the problem of poor electrostatic and electromagnetic protection capabilities on the back of the connector due to the spacing between the first shielding layer and the reinforcing sheet. The technical solution is as follows:

[0007] On the one hand, a flexible circuit board is provided, which includes a board body, a first shielding layer, a reinforcement sheet and a connector, wherein the board body has a first surface and a second surface relative to each other, and the board body has a first end and a second end in the longitudinal direction of the board body; the connector is located on the first surface and at the first end, and the connector is connected to the board body; the reinforcement sheet is located on the second surface and at the first end, and the orthographic projection of the connector on the first surface at least partially overlaps with the orthographic projection of the reinforcement sheet on the first surface; the first shielding layer is located on the second surface, and the first shielding layer is electrically connected to the reinforcement sheet.

[0008] Optionally, the flexible circuit board further includes a conductive adhesive, the reinforcing sheet and the board body are connected via the conductive adhesive, and the reinforcing sheet and the first shielding layer are connected via the conductive adhesive.

[0009] Optionally, the orthographic projection of the first shielding layer on the first surface partially overlaps with the orthographic projection of the reinforcing sheet on the first surface.

[0010] Optionally, a ratio of an area of ​​an overlapping region of an orthographic projection of the first shielding layer on the first surface and an orthographic projection of the reinforcing sheet on the first surface to an area of ​​an orthographic projection of the reinforcing sheet on the first surface is greater than or equal to 10%.

[0011] Optionally, the board body includes a first substrate layer and a first routing layer, the first routing layer is located on the side of the first substrate layer away from the first surface, the board body also has a first opening, the first opening is located on the second surface, the orthographic projection of the first opening on the first surface is located within the orthographic projection of the reinforcement plate on the first surface, and the reinforcement plate is electrically connected to the grounding structure in the first routing layer through the first opening.

[0012] Optionally, an orthographic projection of the first shielding layer on the first surface is located on one side of an orthographic projection of the first opening on the first surface.

[0013] Optionally, an orthographic projection of the first shielding layer on the first surface surrounds an orthographic projection of the first opening on the first surface.

[0014] Optionally, an orthographic projection of the first opening on the first surface is located within an orthographic projection of the first shielding layer on the first surface.

[0015] Optionally, in the width direction of the plate, the ratio of the size of the overlapping area of ​​the orthographic projection of the first shielding layer on the first surface and the orthographic projection of the reinforcing sheet on the first surface to the size of the reinforcing sheet is greater than or equal to 30%.

[0016] Optionally, the first shielding layer and the reinforcing sheet are spaced apart, and the flexible circuit board further includes a transition structure, the transition structure is located on the second surface, and the transition structure connects the reinforcing sheet and the first shielding layer.

[0017] Optionally, the board body further includes a second substrate layer and a second wiring layer, the second substrate layer and the second wiring layer are stacked in sequence on the side of the first substrate layer close to the first surface, and the orthographic projection of the second substrate layer on the first surface does not overlap with the orthographic projection of the reinforcement sheet on the first surface; the flexible circuit board further includes a plurality of components, and the board body further has a plurality of second openings located at the second end, the plurality of components are respectively located in one of the second openings, and the components and the second wiring layer are connected through the second openings.

[0018] Optionally, the board body further has a third opening located at the second end, and the third opening is located on the second surface, and a portion of the first shielding layer is located in the third opening and connected to the grounding structure in the first routing layer.

[0019] On the other hand, a display device is provided, comprising a display panel and any one of the aforementioned flexible circuit boards, wherein the flexible circuit board is located on the back side of the display panel and is electrically connected to the display panel, and the second surface is located on a side of the first surface away from the display panel.

[0020] The beneficial effects brought about by the technical solution provided by the present disclosure include at least: by electrically connecting the first shielding layer with the reinforcement sheet on the back side of the board body for setting the connector, the electrostatic and electromagnetic protection capabilities of the FPC are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] FIG1 is a schematic diagram of a cross-sectional structure of an FPC provided in an embodiment of the present disclosure;

[0023] FIG2 is a partial enlarged schematic diagram of FIG1 ;

[0024] FIG3 is a schematic diagram of a planar structure of an FPC provided in an embodiment of the present disclosure;

[0025] FIG4 is a schematic diagram of a cross-sectional structure of another FPC provided in an embodiment of the present disclosure;

[0026] FIG5 is a schematic diagram of a planar structure of an FPC provided in an embodiment of the present disclosure;

[0027] FIG6 is a schematic diagram of a cross-sectional structure of another FPC provided in an embodiment of the present disclosure;

[0028] FIG7 is a schematic diagram of a planar structure of an FPC provided in an embodiment of the present disclosure;

[0029] FIG8 is a schematic diagram of a cross-sectional structure of another FPC provided in an embodiment of the present disclosure;

[0030] FIG9 is a schematic diagram of a planar structure of an FPC provided in an embodiment of the present disclosure;

[0031] FIG10 is a schematic diagram of a cross-sectional structure of another FPC provided in an embodiment of the present disclosure;

[0032] FIG11 is a schematic diagram of a planar structure of an FPC provided in an embodiment of the present disclosure;

[0033] FIG12 is a schematic flow chart of a method for manufacturing a flexible circuit board according to an embodiment of the present disclosure;

[0034] FIG13 is a partial schematic diagram of a planar structure of a display device provided by an embodiment of the present disclosure.

[0035] Legend: 1. FPC x, first direction y, second direction 10, connection portion 11, board 11a, first surface 11b, second surface 11c, first opening 11d, second opening 11e, third opening 112, first substrate layer 113, second substrate layer 114, first trace layer 115, second trace layer 116, third trace layer 117, fourth trace layer 118, first adhesive layer 119, second adhesive layer 120, third adhesive layer 121, first protective layer 122, second protective layer 12, first shielding layer 12a, first portion 13, reinforcement sheet 14, connector 15, conductive adhesive 16, second shielding layer 18, transfer structure 19, component 21, adhesive layer

[0036] 3. Display panel DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0038] The terms used in the embodiments of the present disclosure are only used to explain the embodiments of the present disclosure and are not intended to limit the present disclosure. Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should be the ordinary meanings understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second", "third" and similar words used in the patent application specification and claims of this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one" or "a" do not indicate a quantitative limitation, but rather indicate the presence of at least one. Similar words such as "include" or "comprise" mean that the elements or objects appearing before "include" or "comprise" cover the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. The directional terms mentioned in the present disclosure, such as "top", "bottom", "up", "down", "left" or "right", etc., are only used to refer to the directions of the drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present disclosure, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present disclosure.

[0039] In related art, a flexible printed circuit board includes a board body, a first shielding layer, a reinforcing sheet, and a connector. The board body has opposing first and second surfaces and opposing first and second ends along its length. The connector is located at the first end and on the first surface and is connected to the board body. The reinforcing sheet is located on the second surface and at the first end, with the orthographic projection of the connector on the first surface at least partially overlapping the orthographic projection of the reinforcing sheet on the first surface. The first shielding layer is located on the second surface, with the first shielding layer and the reinforcing sheet spaced apart. Due to the spacing between the first shielding layer and the reinforcing sheet, there is no electrical connection between the first shielding layer and the reinforcing sheet. For example, the distance between the edge of the orthographic projection of the first shielding layer on the first surface and the edge of the orthographic projection of the reinforcing sheet on the first surface is approximately 1 mm. During use, the gap between the first shielding layer and the reinforcing sheet may cause electromagnetic interference and electrostatic damage. As the internal design of electronic products becomes increasingly complex, these electromagnetic interference and electrostatic damage issues are more likely to occur in high-end products, resulting in reduced signal stability in circuits near the connector and electrostatic damage to circuits near the connector.

[0040] To this end, the embodiment of the present disclosure electrically connects the first shielding layer to the reinforcing sheet to improve the problem of poor electrostatic and electromagnetic protection capabilities on the back of the connector due to the spacing between the first shielding layer and the reinforcing sheet.

[0041] Figure 1 is a schematic cross-sectional view of an FPC provided in an embodiment of the present disclosure, and Figure 2 is a partially enlarged schematic view of Figure 1. As shown in Figures 1 and 2, FPC 1 includes a board 11, a first shielding layer 12, a reinforcing sheet 13, and a connector 14. Board 11 has a first surface 11a and a second surface 11b opposite each other, and has a first end and a second end in the length direction (first direction x) of board 11. Connector 14 is located at the first end and on the first surface 11a, and is connected to board 11. Reinforcing sheet 13 is located on the second surface 11b and at the first end. First shielding layer 12 is located on the second surface 11b, and is electrically connected to reinforcing sheet 13. Figure 3 is a schematic plan view of an FPC provided in an embodiment of the present disclosure, and Figure 1 is a schematic cross-sectional view along section line AA in Figure 3. As shown in Figure 3, the orthographic projection of connector 14 on first surface 11a at least partially overlaps with the orthographic projection of reinforcing sheet 13 on first surface 11a.

[0042] By electrically connecting the reinforcing sheet 13 to the first shielding layer 12, if static electricity occurs on the back of the connector 14, the static electricity current can be discharged from the back of the connector 14 along the electrically connected reinforcing sheet 13 and the first shielding layer 12, thereby providing better static electricity protection in the connector 14 area (the back of the connector 14); and because the structure between the electrically connected reinforcing sheet 13 and the first shielding layer 12, and the area of ​​the positive projection of the reinforcing sheet 13 and the first shielding layer 12 on the first surface 11a are larger than the area of ​​the positive projection of the reinforcing sheet 13 and the first shielding layer 12 arranged at intervals on the first surface 11a in the related art, the embodiment of the present disclosure provides better electromagnetic protection in the connector 14 area (the back of the connector 14).

[0043] It should be noted that the first end and the second end of the plate body 11 are the areas relatively located on the left or right side in the embodiment shown in Figure 3, and do not refer to the area closest to the left edge and the area closest to the right edge of the plate body 11 in the embodiment shown in Figure 3.

[0044] Exemplarily, as shown in Figures 1 to 3, the FPC further includes a conductive adhesive 15, and the reinforcing sheet 13 and the board body 11 are connected via the conductive adhesive 15. The reinforcing sheet 13 and the first shielding layer 12 are also connected via the conductive adhesive 15, thereby achieving an electrical connection between the reinforcing sheet 13 and the first shielding layer 12. Exemplarily, as shown in Figures 1 to 3, the reinforcing sheet 13, the conductive adhesive 15, and the first shielding layer 12 are connected in sequence.

[0045] For example, as shown in Figures 1 to 3 , the orthographic projection of the first shielding layer 12 on the first surface 11a partially overlaps with the orthographic projection of the reinforcing sheet 13 on the first surface 11a. By extending the first shielding layer 12 into the area where the reinforcing sheet 13 is located, a reliable connection between the reinforcing sheet 13 and the first shielding layer 12 is further ensured, thereby ensuring a reliable electrical connection between the first shielding layer 12 and the reinforcing sheet 13. This design process is relatively simple and easy to implement.

[0046] In other possible embodiments, a gap exists between the edge of the orthographic projection of the first shielding layer 12 on the first surface 11a and the orthographic projection of the reinforcing sheet 13 on the first surface 11a. The orthographic projection of the conductive adhesive 15 on the first surface 11a partially overlaps with the orthographic projection of the first shielding layer 12 on the first surface 11a, and the orthographic projection of the conductive adhesive 15 on the first surface 11a partially overlaps with the orthographic projection of the reinforcing sheet 13 on the first surface 11a. In other words, the first shielding layer 12 and the reinforcing sheet 13 are spaced apart, but the conductive adhesive 15 extends beyond the area of ​​the reinforcing sheet 13 until it connects with the first shielding layer 12. This approach can also achieve electrical connection between the first shielding layer 12 and the reinforcing sheet 13.

[0047] For example, as shown in Figure 3, the ratio of the area of ​​the overlapping region between the orthographic projection of the first shielding layer 12 on the first surface 11a and the orthographic projection of the reinforcing sheet 13 on the first surface 11a to the area of ​​the orthographic projection of the reinforcing sheet 13 on the first surface is greater than or equal to 10%. Setting the overlapping area to be greater than or equal to 10% ensures that the overlap between the first shielding layer 12 and the reinforcing sheet 13 is sufficiently large, thereby improving the electrostatic and electromagnetic protection capabilities of the back side of the connector in the FPC.

[0048] Exemplarily, the first shielding layer 12 includes a first portion 12a located at the first end. The portion of the orthographic projection of the first shielding layer 12 on the first surface 11a that overlaps with the orthographic projection of the reinforcing sheet 13 on the first surface 11a is the orthographic projection of the first portion 12a on the first surface 11a. The ratio of the dimension of the first portion 12a in the second direction y to the dimension of the reinforcing sheet 13 in the second direction y is greater than or equal to 30%. The second direction y is the width of the board 11. If the ratio of the dimension of the first portion 12a in the second direction y to the dimension of the reinforcing sheet 13 in the second direction y is too small, the narrowness of the first portion 12a may result in a large current flowing through the reinforcing sheet 13 and the first shielding layer 12 if static electricity is present on the back of the connector.

[0049] Exemplarily, the connector 14 is a board-to-board (BTB) connector or a zero insertion force (ZIF) connector. Different types of connectors can be selected in different application scenarios. For example, in display devices, board-to-board connectors are often used.

[0050] 2 , the board 11 includes a first substrate layer 112 and a first routing layer 114. The first routing layer 114 is located on a side of the first substrate layer 112 away from the first surface 11a. The first routing layer 114 may include a grounding structure and routing lines connected to the connector 14.

[0051] Optionally, the board body 11 also includes a first opening located at the first end, and the first opening is located on the second surface, so as to facilitate setting a grounded exposed copper area on the back of the connector, so that the conductive glue is electrically connected to the grounding structure in the first wiring layer through the first opening, further improving the electrostatic and electromagnetic protection capabilities.

[0052] For example, as shown in Figures 1 and 2, the board body 11 further includes a second substrate layer 113 and a second wiring layer 115. The second substrate layer 113 and the second wiring layer 115 are stacked sequentially on the side of the first substrate layer 112 near the first surface 11a. The orthographic projection of the second substrate layer 113 on the first surface 11a does not overlap with the orthographic projection of the reinforcement sheet 13 on the first surface 11a. That is, the first substrate layer 112 is located below the connector, but the second substrate layer 113 is not. The flexible circuit board also includes multiple components 19. The board body 11 further has multiple second openings 11d at the second end. Each component 19 is located in one of the second openings 11d, and the components 19 and the second wiring layer 115 are connected through the second openings 11d. Providing more substrate layers and correspondingly more wiring layers at the second end of the FPC facilitates component placement. Multiple wiring layers facilitate wiring and enhance the strength of the second end of the flexible circuit board. Providing fewer substrate layers and correspondingly fewer wiring layers at the first end facilitates bending. Optionally, the multiple components 19 may include resistors, capacitors, or touch control chips.

[0053] Exemplarily, as shown in Figure 2, the FPC also includes a second shielding layer 16, which is located on the first surface 11a of the board 11. That is, the first shielding layer 12 and the second shielding layer 16 are located on opposite surfaces of the board 11, further enhancing the FPC's electrostatic and electromagnetic protection capabilities. Exemplarily, as shown in Figures 1 and 2, the second shielding layer 16 includes multiple escape holes, and the orthographic projections of multiple components 19 on the first surface 11a are located within the orthographic projections of the multiple escape holes on the first surface 11a. The provision of the multiple escape holes facilitates exposure of the multiple components 19.

[0054] 2 , the FPC further comprises an adhesive layer 21, which is located on the side of the first shielding layer 12 away from the board 11. The adhesive layer 21 is provided to facilitate fixing the FPC, for example, by gluing the FPC to the back of the display panel.

[0055] Exemplarily, as shown in FIG3 , the FPC has a connecting portion 10 , which facilitates connection of the FPC with other structures in the display device, such as a display panel.

[0056] Taking the embodiment shown in FIG. 1 to FIG. 3 as an example, the structure of each layer in the plate body 11 is exemplarily described below.

[0057] For example, as shown in FIG2 , the board 11 further includes a third routing layer 116, a fourth routing layer 117, a first adhesive layer 118, a second adhesive layer 119, a third adhesive layer 120, a first protective layer 121, and a second protective layer 122. The first protective layer 121, the second adhesive layer 119, the first routing layer 114, the first substrate layer 112, the third routing layer 116, the first adhesive layer 118, the fourth routing layer 117, the second substrate layer 113, the second routing layer 115, the third adhesive layer 120, and the second protective layer 122 are stacked in sequence. The second opening 11d extends through the third adhesive layer 120 and the second protective layer 122.

[0058] Among them, the connecting part 10 shown in Figure 3 can be a part of the first substrate layer 112 and a part of the first wiring layer 114, wherein the first wiring layer 114 includes a plurality of first conductive sheets (also called gold fingers) to facilitate electrical connection with the display panel; or, the connecting part 10 can also be a part of the second substrate layer 113 and a part of the fourth wiring layer 117, wherein the fourth wiring layer 117 includes a plurality of first conductive sheets to facilitate electrical connection with the display panel.

[0059] In other possible embodiments, more routing layers may be provided, as long as the number of routing layers at the second end is greater than the number of routing layers at the first end.

[0060] In other possible embodiments, the first end and the second end may be provided with the same number of routing layers.

[0061] Optionally, the first substrate layer 112 and the second substrate layer 113 are made of PI (Polyimide), which has good bending properties and can ensure the overall bending properties of the FPC. The first substrate layer 112 and the second substrate layer 113 can also be made of PE (Polyethylene), PET (polyethylene glycol terephthalate), etc.

[0062] Optionally, the first wiring layer 114 , the second wiring layer 115 , the third wiring layer 116 and the fourth wiring layer 117 are made of copper, such as rolled copper or electrolytic copper.

[0063] Optionally, as shown in Figure 3, the first substrate layer 112, the first routing layer 114 and the third routing layer 116 located on both sides of the first substrate layer 112 extend from the first end to the second end, and the second substrate layer 113, the second routing layer 115 and the fourth routing layer 117 located on both sides of the second substrate layer 113 are located at the second end, that is, the second routing layer 115 and the fourth routing layer 117 are not located under the connector 14.

[0064] Optionally, the first protective layer 11 and the second protective layer 15 are made of PI, thereby providing protection for the FPC.

[0065] Optionally, the materials of the first adhesive layer 118 , the second adhesive layer 119 and the third adhesive layer 120 may be acrylic hot melt adhesive, polyurethane adhesive, epoxy resin adhesive, etc.

[0066] Optionally, the thickness of the first adhesive layer 118 is greater than the thickness of the second adhesive layer 119, and the thickness of the first adhesive layer 118 is greater than the thickness of the third adhesive layer 120, so as to bond the connected first routing layer 114, the first substrate layer 112, and the third routing layer 116 as a whole, and the connected second routing layer 115, the second substrate layer 113, and the fourth routing layer 117 as a whole.

[0067] FIG4 is a schematic diagram of the cross-sectional structure of another FPC provided by an embodiment of the present disclosure, and FIG5 is a schematic diagram of the planar structure of an FPC provided by an embodiment of the present disclosure. Compared with the embodiments shown in FIG1 to FIG3 , in the embodiments shown in FIG4 and FIG5 , the board body 11 further has a first opening 11c located at the first end, and the first opening 11c is located on the second surface 11b, and the orthographic projection of the first opening 11c on the first surface 11a is located within the orthographic projection of the reinforcing plate 13 on the first surface 11a, and the reinforcing plate 13 is electrically connected to the first wiring layer 114, and the portion of the first wiring layer 114 connected to the reinforcing plate 13 in the first wiring layer 114 is used for grounding, and this portion of the first wiring layer 114 can also be called a grounding structure. The first opening 11c provided on the back of the connector 14 is a grounding exposed copper area, and the provision of the first opening 11c can improve the electrostatic protection capability of the connector 14.

[0068] For example, as shown in FIG4 , the plate body 11 further has a third opening 11e at the second end, and the third opening 11e is located on the second surface 11b. The first shielding layer 12 is located in the third opening 11e and is connected to the first routing layer 114. The portion of the first routing layer 114 connected to the first shielding layer 12 is used for grounding. Providing the third opening 11e at the second end, that is, providing a grounded exposed copper area on the back of the component 19, can improve electrostatic protection capabilities.

[0069] Exemplarily, as shown in FIG. 4 , the first opening 11 c penetrates through 121 and 119 , and the third opening 11 e penetrates through the first protective layer 121 and the second adhesive layer 119 .

[0070] In the embodiments shown in Figures 4 and 5 , the orthographic projection of first portion 12a on first surface 11a is located on one side of the orthographic projection of first opening 11c on first surface 11a. By extending first shielding layer 12 to the side of the first opening closer to the second end, a reliable connection between first shielding layer 12 and the conductive adhesive is ensured, thereby ensuring a reliable electrical connection between first shielding layer 12 and reinforcing sheet 13.

[0071] Optionally, as shown in Figures 4 and 5, the flexible circuit board also includes a conductive glue 15, which is filled in the first opening 11c. Since the first shielding layer 12 and the reinforcement plate 13 are connected, the grounded exposed copper area on the back of the connector 14, the conductive glue, the reinforcement plate, and the first shielding layer are electrically connected.

[0072] Figure 6 is a schematic diagram of the cross-sectional structure of another FPC provided in an embodiment of the present disclosure, and Figure 7 is a schematic diagram of the planar structure of an FPC provided in an embodiment of the present disclosure. Compared with the embodiments shown in Figures 1 to 3, in the embodiments shown in Figures 6 and 7, the plate body 11 has a first opening 11c and a third opening 114f similar to those in the embodiments shown in Figures 4 and 5. In addition, the orthographic projection of the first portion 12a on the first surface 11a surrounds the orthographic projection of the first opening 11c on the first surface 11a. This design can further increase the overlapping area of ​​the first shielding layer 12 and the reinforcement sheet 13, further improving the electrostatic and electromagnetic protection capabilities compared to the embodiments shown in Figures 5 and 6.

[0073] FIG8 is a schematic diagram of the cross-sectional structure of another FPC provided in an embodiment of the present disclosure, and FIG9 is a schematic diagram of the planar structure of an FPC provided in an embodiment of the present disclosure. Compared with the embodiments shown in FIG1 to FIG3, in the embodiments shown in FIG8 and FIG9, the board 11 has a first opening 11c and a third opening 11e similar to those in the embodiments shown in FIG4 and FIG5. In addition, the orthographic projection of the first opening 11c on the first surface 11a is located within the orthographic projection of the first portion 12a on the first surface 11a. This design can further increase the area of ​​the orthographic projection of the first portion 11a on the first surface 11a, that is, this design can further increase the overlapping area of ​​the first shielding layer 12 and the reinforcement sheet 13, further improving the electrostatic and electromagnetic protection capabilities compared to the embodiments shown in FIG6 and FIG7. In the embodiments shown in FIG8 and FIG9, the grounded exposed copper area on the back of the connector 14 located in the first opening 11c is in direct contact with the first shielding layer 12.

[0074] In the embodiments shown in Figures 1 to 9 above, the electrical connection between the first shielding layer 12 and the reinforcing sheet 13 is achieved by extending the first shielding layer 12 toward the first end until the first shielding layer 12 overlaps the reinforcing sheet 13. In other possible embodiments, this electrical connection between the first shielding layer 12 and the reinforcing sheet 13 may not be achieved. Other exemplary methods for achieving the electrical connection between the first shielding layer 12 and the reinforcing sheet 13 are described below with reference to Figure 10.

[0075] Figure 10 is a schematic cross-sectional view of another FPC provided in an embodiment of the present disclosure, and Figure 11 is a schematic plan view of an FPC provided in an embodiment of the present disclosure, with Figure 10 being a schematic partial cross-sectional view along line BB in Figure 11. As shown in Figures 10 and 11, first shielding layer 12 is spaced apart from reinforcing sheet 13. The FPC also includes a transition structure 18, which is located on second surface 11b and connects reinforcing sheet 13 and first shielding layer 12. The provision of transition structure 18 establishes an electrical connection between reinforcing sheet 13 and first shielding layer 12, improving the FPC's electrostatic and electromagnetic protection capabilities.

[0076] Optionally, the transition structure 11 b includes a main body and a protruding portion. The main body is located on a side of the first protective layer 121 away from the first surface and is connected to the reinforcing sheet 13 . The protruding portion is used to connect to the first protective layer 121 .

[0077] Optionally, the transition structure 18 is made of a conductive material, such as a metal material such as copper.

[0078] Optionally, the orthographic projection of the transition structure 18 on the first surface 11 a may be a rectangle as shown in FIG. 10 and FIG. 11 , or may be other shapes, which is not limited in the embodiment of the present disclosure.

[0079] Optionally, the reinforcing sheet 13 and the body 11 are connected by non-conductive glue or conductive glue.

[0080] FIG12 is a flow chart of a method for manufacturing a flexible circuit board according to an embodiment of the present disclosure. As shown in FIG12 , the method includes:

[0081] In step S1, a plate body is provided, wherein the plate body has a first surface and a second surface opposite to each other, and the plate body has a first end and a second end in a length direction of the plate body;

[0082] In step S2, a first shielding layer, a reinforcing sheet and a connector are arranged on the board.

[0083] The connector is located on the first surface and at the first end, the connector is connected to the board, the reinforcing plate is located on the second surface and at the first end, the orthographic projection of the connector on the first surface and the orthographic projection of the reinforcing plate on the first surface at least partially overlap, the first shielding layer is located on the second surface, and the first shielding layer is electrically connected to the reinforcing plate.

[0084] Exemplarily, step S2 includes: firstly manufacturing a first shielding layer of a specific shape by die-cutting or laser cutting, and then pasting the first shielding layer to the second surface of the board.

[0085] For example, conductive tape or non-conductive tape is first applied to the plate 11, and then the reinforcing sheet is attached to achieve connection between the plate and the reinforcing sheet. In other possible embodiments, liquid conductive adhesive or non-conductive adhesive is first applied to the plate 11, and then the reinforcing sheet is attached to achieve connection between the plate and the reinforcing sheet.

[0086] Exemplarily, the board and the connector are connected by an SMT (Surface Mounted Technology) process.

[0087] Figure 13 is a partial schematic diagram of the planar structure of a display device provided by an embodiment of the present disclosure. As shown in Figure 13, the display device includes a display panel 3 and any of the aforementioned flexible circuit boards 1. Flexible circuit board 1 is located on the back side of display panel 3 and is electrically connected to display panel 3. The second surface of flexible circuit board 1 is located on the side of the first surface away from display panel 3.

[0088] Illustratively, the display device provided in the embodiments of the present disclosure may be any product or component with a display function, such as a mobile phone, a tablet computer, or a monitor.

[0089] For example, in the display device provided in the embodiment of the present disclosure, the display panel may be: a liquid crystal display panel, an OLED (Organic Light Emitting Diode) display panel, a QLED (Quantum Dot Light Emitting Diode) display panel, etc., and the embodiment of the present disclosure does not make specific limitations here.

[0090] The display device has the same effect as the aforementioned FPC, which will not be described in detail here.

[0091] For example, the display panel 3 has a side that bends toward the back of the display panel, so that a DDIC (Display Driver IC) (not shown) can be installed on this portion of the display panel 3 that bends toward the back of the display panel. This design can minimize the area of ​​the non-display area B, that is, it facilitates a narrow bezel design. Here, the back of the display panel 3 refers to the other surface of the display panel 3 opposite the light-emitting surface.

[0092] For example, one side of the display panel is bent toward the back of the display panel, and this bent portion of the display panel has a packaged circuit board (not shown). This packaged circuit board, which is integrally formed with the display panel, is called a COP (Chip On Pi, chip-on-flexible material) circuit board. In other possible embodiments, the packaged circuit board may also be a COG (Chip On Glass, chip-on-glass) circuit board or a COF (Chip On Film, chip-on-film) circuit board. The packaged circuit board includes a DDIC.

[0093] For example, the FPC in the disclosed embodiment is a main flexible printed circuit (MFPC). The display device also includes a central processing unit (CPU) (not shown). The connecting portion 10 of the FPC 1 is connected to the DDIC. The first end of the FPC 1 can be bent and connected to the CPU via a connector. The CPU controls the DDIC on the packaged circuit board via the FPC 1, thereby controlling the display panel 3.

[0094] Exemplarily, the package circuit board has multiple second conductive sheets, each corresponding to the multiple first conductive sheets in the connection portion of the FPC. The display device also includes an ACF (Anisotropic Conductive Film) film, which is positioned between the first and second conductive sheets. The ACF film includes an adhesive layer and multiple metal balls (e.g., gold balls) distributed within the adhesive layer. The first conductive sheet, the ACF film, and the second conductive sheet are sequentially connected.

[0095] Exemplarily, a back film is further provided on the back of the display panel 3 to protect the display panel 3 .

[0096] For example, a ground layer is provided on the side of the back film away from the display panel, and the ground layer includes an SCF (Super Clean Foam) layer, also known as a heat dissipation film. The first shielding layer of FPC1 is connected to the SCF layer.

[0097] Exemplarily, the display device further includes a polarizer, which is located on a side of the display panel 3 away from the FPC 1 , that is, the polarizer is located on the light-emitting surface of the display panel.

[0098] Exemplarily, the display device further includes a cover plate, which is located on the light-emitting surface of the display panel. Optionally, the cover plate can be made of a transparent material such as acrylic or glass.

[0099] The above are merely optional embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the scope of protection of the present disclosure.

Claims

1. A flexible circuit board, characterized in that: The flexible circuit board includes a board body, a first shielding layer, a reinforcing sheet and a connector, wherein the board body has a first surface and a second surface opposite to each other, and the board body has a first end and a second end in the length direction of the board body; The connector is located on the first surface and at the first end, and the connector is connected to the board; The reinforcing sheet is located on the second surface and at the first end, and the orthographic projection of the connector on the first surface at least partially overlaps with the orthographic projection of the reinforcing sheet on the first surface; The first shielding layer is located on the second surface, and the first shielding layer is electrically connected to the reinforcing sheet.

2. The flexible circuit board according to claim 1, wherein: The flexible circuit board further includes a conductive adhesive, the reinforcing sheet and the board body are connected via the conductive adhesive, and the reinforcing sheet and the first shielding layer are connected via the conductive adhesive.

3. The flexible circuit board according to claim 2, wherein: The orthographic projection of the first shielding layer on the first surface partially overlaps with the orthographic projection of the reinforcing sheet on the first surface.

4. The flexible circuit board according to claim 3, characterized in that: A ratio of an area of ​​an overlapping region between an orthographic projection of the first shielding layer on the first surface and an orthographic projection of the reinforcing sheet on the first surface to an area of ​​the orthographic projection of the reinforcing sheet on the first surface is greater than or equal to 10%.

5. The flexible circuit board according to claim 4, characterized in that: The board body includes a first base material layer and a first routing layer, the first routing layer is located on the side of the first base material layer away from the first surface, the board body also has a first opening, the first opening is located on the second surface, the orthographic projection of the first opening on the first surface is located within the orthographic projection of the reinforcement plate on the first surface, and the reinforcement plate is electrically connected to the grounding structure in the first routing layer through the first opening.

6. The flexible circuit board according to claim 5, characterized in that: An orthographic projection of the first shielding layer on the first surface is located on one side of an orthographic projection of the first opening on the first surface.

7. The flexible circuit board according to claim 5, characterized in that: The orthographic projection of the first shielding layer on the first surface surrounds the orthographic projection of the first opening on the first surface.

8. The flexible circuit board according to claim 5, wherein: An orthographic projection of the first opening on the first surface is located within an orthographic projection of the first shielding layer on the first surface.

9. The flexible circuit board according to any one of claims 3 to 8, characterized in that: In the width direction of the plate, a ratio of a size of an overlapping area between an orthographic projection of the first shielding layer on the first surface and an orthographic projection of the reinforcing sheet on the first surface to a size of the reinforcing sheet is greater than or equal to 30%.

10. The flexible circuit board according to claim 1, wherein: The first shielding layer and the reinforcing sheet are spaced apart from each other. The flexible circuit board further includes a transition structure, which is located on the second surface and connects the reinforcing sheet and the first shielding layer.

11. The flexible circuit board according to any one of claims 5 to 8, characterized in that: The board further includes a second base material layer and a second wiring layer, the second base material layer and the second wiring layer are stacked in sequence on a side of the first base material layer close to the first surface, and an orthographic projection of the second base material layer on the first surface does not overlap with an orthographic projection of the reinforcing sheet on the first surface; The flexible circuit board further includes a plurality of components. The board body further has a plurality of second openings located at the second end. The plurality of components are respectively located in one of the second openings. The components and the second wiring layer are connected through the second openings.

12. The flexible circuit board according to any one of claims 5 to 8, characterized in that: The board body further has a third opening located at the second end, and the third opening is located on the second surface. A portion of the first shielding layer is located in the third opening and is connected to the grounding structure in the first wiring layer.

13. A display device, characterized in that: The display device includes a display panel and a flexible circuit board according to any one of claims 1 to 12, wherein the flexible circuit board is located on the back side of the display panel and is electrically connected to the display panel, and the second surface is located on a side of the first surface away from the display panel.

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