Printed circuit board, manufacturing method thereof, and display device

Abstract

The application provides a printed circuit board, a preparation method thereof and a display device. The printed circuit board comprises a hard board area and a soft board area. The soft board area is located at the periphery of a first edge of the hard board area. The printed circuit board of the hard board area comprises a substrate, an adhesive film, a cover film and a first metal layer which are stacked on one side of the substrate. The adhesive film is arranged close to the substrate. The cover film is provided with a flow guide groove on the surface close to the adhesive film. The flow guide groove extends to a second edge of the hard board area. By arranging the flow guide groove on the surface of the cover film close to the adhesive film and extending the flow guide groove to the second edge of the hard board area, the overflow of the adhesive film can be effectively guided to the periphery of the second edge through the flow guide groove. Since the soft board area is located at the periphery of the first edge, the overflow of the adhesive film to the soft board area can be effectively reduced, the reserved overflow space of the printed circuit board is reduced, and the size of the printed circuit board is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a printed wiring board, a preparation method thereof and a display device. BACKGROUND

[0002] At present, the demand for full-screen, long battery life and 5G communication of display products is becoming more and more prominent, and these demands all require the structure of the display module to be more and more compact, so as to leave space to realize larger battery capacity, smaller frame and larger antenna clearance, etc.

[0003] The size of the flexible printed wiring board (FPC) has a great influence on the compactness of the display module structure. In the related art, when designing the FPC, in addition to meeting the wiring demand, an additional space is also reserved for the overflow of the adhesive film, otherwise the adhesive film may overflow to the gold finger area in the soft board area, resulting in that the gold finger area cannot be bound with the FPC, or the soft board area becomes hard and cannot be bent. SUMMARY

[0004] The present application provides a printed wiring board, a preparation method thereof and a display device, to reduce the occupied space of the overflow area in the printed wiring board.

[0005] In order to solve the above problems, the present application discloses a printed wiring board, which comprises a hard board area and a soft board area, the soft board area is located at the periphery of the first edge of the hard board area.

[0006] The printed wiring board of the hard board area comprises a substrate, an adhesive film, a cover film and a first metal layer which are stacked on one side of the substrate, the adhesive film is arranged close to the substrate, the cover film is provided with a flow guide groove on the surface of the side close to the adhesive film, and the flow guide groove extends to the second edge of the hard board area.

[0007] In an optional implementation, the shape of the hard board area is quadrilateral, the first edge comprises a first side edge of the hard board area and a second side edge opposite to the first side edge, the second edge comprises a third side edge of the hard board area and a fourth side edge opposite to the third side edge, one end of the flow guide groove extends to the third side edge, and the other end extends to the fourth side edge.

[0008] In an optional implementation, the number of the flow guide grooves is multiple, and the multiple flow guide grooves are arranged equidistantly and parallelly.

[0009] In an optional implementation, the extension direction of the flow guide groove is parallel to the junction line of the hard board area and the soft board area.

[0010] In an optional implementation, the flow guide groove comprises a first groove and a second groove which are in communication with each other, wherein the first groove extends in parallel to the junction line between the hard board region and the soft board region, and the second groove is bent towards the junction line.

[0011] In an optional implementation, the distance between the flow guide groove and the soft board region is greater than or equal to 1 mm.

[0012] In an optional implementation, the depth of the flow guide groove is less than or equal to half of the thickness of the cover film.

[0013] In an optional implementation, the depth of the flow guide groove is greater than or equal to 2 μm and less than or equal to 10 μm.

[0014] In an optional implementation, the orthographic projection of the groove opening of the flow guide groove on the substrate covers the orthographic projection of the groove bottom of the flow guide groove on the substrate.

[0015] In an optional implementation, in a direction perpendicular to the extension direction of the flow guide groove, the groove opening width of the flow guide groove is greater than or equal to 0.5 mm and less than or equal to 1 mm.

[0016] In an optional implementation, the material of the cover film comprises polyimide.

[0017] In an optional implementation, the adhesive film is formed by curing a semi-cured insulating adhesive sheet.

[0018] In an optional implementation, the adhesive film, the cover film and the first metal layer are symmetrically arranged on both sides of the substrate, and a solder resist layer is further arranged on the side of the first metal layer away from the substrate.

[0019] To solve the above problems, the present application discloses a display device, which comprises a display panel and a printed circuit board as claimed in any one of the preceding claims connected to the display panel.

[0020] In an optional implementation, the display device further comprises a chip on film, and the printed circuit board and the display panel are connected through the chip on film.

[0021] To solve the above problems, the present application discloses a method for manufacturing a printed circuit board, which comprises a hard board region and a soft board region, and the soft board region is located at the periphery of a first edge of the hard board region; the method for manufacturing the printed circuit board of the hard board region comprises:

[0022] providing a substrate;

[0023] The adhesive film, the cover film and the first metal layer are sequentially attached on one side of the substrate, wherein a flow guide groove is arranged on the surface of the cover film close to the adhesive film, the flow guide groove extends to the second edge of the hard plate area, and the flow guide groove is used for guiding the overflow of the adhesive film to the peripheral area of the second edge.

[0024] The peripheral area of the second edge is cut off along the second edge to obtain the printed circuit board.

[0025] Compared with the prior art, the present application has the following advantages:

[0026] The technical scheme of the present application provides a printed circuit board, a preparation method thereof and a display device, wherein the printed circuit board comprises a hard plate area and a soft plate area, and the soft plate area is located at the periphery of the first edge of the hard plate area; the printed circuit board of the hard plate area comprises a substrate, and an adhesive film, a cover film and a first metal layer which are sequentially arranged on one side of the substrate; the adhesive film is arranged close to the substrate; the cover film is provided with a flow guide groove on the surface close to the adhesive film; and the flow guide groove extends to the second edge of the hard plate area. According to the technical scheme of the present application, the flow guide groove is arranged on the surface of the cover film close to the adhesive film, and the flow guide groove extends to the second edge of the hard plate area, so that during the process of attaching and pressing the first metal layer, the overflow of the adhesive film can be effectively guided to the periphery of the second edge of the hard plate area through the flow guide groove. Since the soft plate area is located at the periphery of the first edge of the hard plate area, the present scheme can effectively reduce the overflow of the adhesive flowing to the soft plate area, reduce the amount of overflow of the adhesive in the soft plate area, and thus can reduce the reserved overflow space of the printed circuit board, effectively reduce the design size of the printed circuit board, meet the demand of the terminal for compact space of the display module, and improve the compactness of the display device. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the drawings needed to be used in the description of the embodiments of the present application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0028] Figure 1 A structure schematic diagram of a printed circuit board in the related art is shown;

[0029] Figure 2 A structure schematic diagram of another printed circuit board in the related art is shown;

[0030] Figure 3 A structure schematic diagram of a printed circuit board provided by an embodiment of the present application is shown;

[0031] Figure 4Fig. 1 shows a structural schematic diagram of a first covering film provided by an embodiment of the present application;

[0032] Figure 5 Fig. 2 shows a structural schematic diagram of a second covering film provided by an embodiment of the present application;

[0033] Figure 6 Fig. 3 shows a structural schematic diagram of a third covering film provided by an embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to make the above objectives, characteristics and advantages of the present application more apparent and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0035] Reference Figure 1 , Figure 1 a shows a cross-sectional structural schematic diagram of a printed circuit board in the related art, Figure 1 b shows a planar structural schematic diagram of a printed circuit board in the related art. In the printed circuit board in the related art, in addition to the wiring space, an additional space is also needed for the overflow of the adhesive film, that is, an additional overflow area needs to be reserved, otherwise the adhesive film may overflow into the soft plate area, resulting in that the gold fingers in the soft plate area cannot be bound by the FPC, or the soft plate area becomes hard and cannot be bent.

[0036] In the related art, the scheme for improving overflow is usually to shrink the adhesive film (that is, the adhesive film is retracted relative to the copper foil), as shown in Figure 2 However, since the overflow of the adhesive film is not uniform, the overflow amount in some areas may be small, resulting in that the overflow cannot fill the entire copper foil area, and there is a suspended area at the edge of the copper foil, and after the pressing process, the edge of the copper foil is bent, and the bent edge of the copper foil is easy to cause short circuit, open circuit and other defects.

[0037] An embodiment of the present application provides a printed circuit board, referring to Figure 3 a shows a cross-sectional structural schematic diagram of a printed circuit board provided by the embodiment, referring to Figure 3 b shows a planar structural schematic diagram of a printed circuit board provided by the embodiment. The printed circuit board includes a hard plate area 30 and a soft plate area 31, and the soft plate area 31 is located at the periphery of a first edge 30a of the hard plate area 30. As shown in Figure 3 a, the printed circuit board of the hard plate area 30 includes a substrate 301, and an adhesive film 302, a covering film 303 and a first metal layer 304 which are stacked on one side of the substrate 301, the adhesive film 302 is arranged close to the substrate 301, the covering film 303 is arranged on the surface of one side of the adhesive film 302, and the covering film 303 is provided with a flow guide groove 3030 which extends to a second edge 30b of the hard plate area 30.

[0038] The printed circuit board in this embodiment is a rigid-flex board. The number of printed circuit board layers in the rigid board area 30 is greater than that in the flexible board area 31. Furthermore, due to the presence of adhesive film 302 in the rigid board area 30, the hardness of the rigid board area 30 is greater than that of the flexible board area 31.

[0039] The printed circuit board in the rigid board area 30 may be one of a double-layer printed circuit board, a three-layer printed circuit board, a four-layer printed circuit board, a five-layer printed circuit board, a six-layer printed circuit board, a seven-layer printed circuit board, an eight-layer printed circuit board, etc., which is not limited in this embodiment.

[0040] The material of the cover film 303 may include a polymer film material such as polyimide, which is not limited in this embodiment.

[0041] Adhesive film 302 can be formed by curing a pre-cured insulating film or other material, which is not limited in this embodiment. The pre-cured insulating film can be FPC curing adhesive, also known as PrePreg, which is generally used to bond the inner conductive patterns and provide interlayer insulation on multi-layer printed circuit boards. During lamination, the epoxy resin (AD adhesive) in the pre-cured film melts, flows, and solidifies, bonding the various circuit layers together to form a reliable insulation layer.

[0042] like Figure 3 As shown in FIG. 1 , the adhesive film 302, the covering film 303 and the first metal layer 304 can be symmetrically arranged on both sides of the substrate 301. A solder resist layer 305 can also be provided on the side of the first metal layer 304 facing away from the substrate 301. The solder resist layer 305 is used to protect the internal structure of the printed circuit board.

[0043] Alternatively, as Figure 3 As shown in FIG. 1 , the substrate 301 may include a base 3011 and second metal layers 3012 symmetrically arranged on both sides of the base 3011. The adhesive film 302 is arranged on the side of the second metal layer 3012 facing away from the base 3011. The material of the base 3011 may include a polymer film material such as polyimide.

[0044] The materials of the first metal layer 304 and the second metal layer 3012 may be, for example, copper foil, etc., which is not limited in this embodiment.

[0045] A guide groove 3030 is provided on the laminating surface of the cover film 303 facing the adhesive film 302. This guide groove 3030 is used to guide excess adhesive from the adhesive film 302 to the periphery of the second edge 30b. During the lamination and lamination process of the first metal layer 304, excess adhesive from the adhesive film 302 can effectively flow through the guide groove 3030 on the cover film 303 to the periphery of the second edge 30b. The periphery of the second edge 30b is a region of enhanced adhesive overflow, and neither the flexible board area 31 nor the rigid-flexible bonding area is provided within this region. Therefore, after the lamination and lamination process is completed, the laminate can be cut along the second edge 30b, and the excess adhesive diverted through the guide groove 3030 can be removed along with the leftover material of the multilayer board. By providing a guide groove 3030 on the covering film 303, the overflowing glue is guided to the periphery of the second edge 30b, which can effectively reduce or eliminate the amount of overflowing glue in the periphery of the first edge 30a, that is, the flexible board area 31. When designing the printed circuit board, the reserved space for overflowing glue can be reduced, thereby effectively reducing the design space of the printed circuit board.

[0046] Since the amount of glue overflowing into the flexible board area 31 is reduced or eliminated, the reserved glue overflow length can be shortened, so that a smaller printed circuit board size can also effectively avoid the problem of glue overflowing into the gold finger area, which may cause the gold finger area to be unable to be bound, and avoid the problem of glue overflowing into the flexible board area 31, which may cause the flexible board area 31 to become hard and unable to bend.

[0047] The printed circuit board provided in this embodiment is provided with a guide groove 3030 on the surface of the covering film 303 on the side close to the adhesive film 302, and the guide groove 3030 extends to the second edge 30b of the hard board area 30, so that in the process of laminating and laminating the first metal layer 304, the overflow of the adhesive film 302 can be effectively guided to the periphery of the second edge 30b of the hard board area 30 through the guide groove 3030. Since the soft board area 31 is located outside the first edge 30a of the hard board area 30, this solution can effectively reduce the overflow of glue flowing to the soft board area 31, reduce the amount of overflow of glue in the soft board area 31, and further reduce the reserved overflow space of the soft board area 31, effectively reducing the design size of the printed circuit board, meeting the terminal's demand for a compact space of the display module, reducing costs while effectively reducing the spatial structure of the display module, improving the compactness of the display module, and better meeting the needs of terminal customers.

[0048] In an optional implementation, Figure 3 As shown in b, the shape of the hard plate area 30 is a quadrilateral, the first edge 30a includes a first side a1 of the hard plate area 30 and a second side a2 opposite to the first side a1, the second edge 30b includes a third side b1 of the hard plate area 30 and a fourth side b2 opposite to the third side b1, and one end of the guide groove 3030 extends to the third side b1, and the other end extends to the fourth side b2.

[0049] In the present embodiment, the soft board area 31 is located at the periphery of the first side edge a1 and the periphery of the second side edge a2 respectively.

[0050] In the present embodiment, the flow guide groove 3030 is a groove penetrating through the cover film 303 along the extending direction, i.e., the two ports of the flow guide groove 3030 extend to the third side edge b1 and the fourth side edge b2 respectively, so that the flow guide groove 3030 can sufficiently guide the overflow glue to the periphery of the third side edge b1 and the periphery of the fourth side edge b2, thereby reducing the overflow glue amount of the soft board area 31 and reducing the reserved overflow glue space of the printed circuit board. Of course, according to actual needs, one port of the flow guide groove 3030 can extend to the third side edge b1, and the other port can be arranged inside the cover film 303, which is not limited in the present embodiment.

[0051] In a specific implementation, a plurality of flow guide grooves 3030 can be arranged on the side surface of the cover film 303 close to the glue film 302, as shown in Figure 4 or Figure 6 In the present embodiment, three flow guide grooves 3030 are arranged on the cover film 303; or one flow guide groove 3030 can be arranged, as shown in Figure 5 In a specific implementation, the number of grooves can be designed according to the space of the printed circuit board, the slot width of the flow guide groove and the thickness of the glue film 302, which is not limited in the present embodiment. When a plurality of flow guide grooves 3030 are arranged on the side surface of the cover film 303 close to the glue film 302, the process difficulty of grooving can be reduced.

[0052] In the present embodiment, the cover film 303 is provided with a flow guide groove 3030, and the flow guide groove 3030 is arranged on the side surface of the cover film 303 close to the glue film 302. Figure 4 a shows a cross-sectional structure schematic diagram of a first cover film provided by the present embodiment, Figure 4 b shows a plane structure schematic diagram of the first cover film provided by the present embodiment. Figure 5 a shows a cross-sectional structure schematic diagram of a second cover film provided by the present embodiment, Figure 5 b shows a plane structure schematic diagram of the second cover film provided by the present embodiment. Figure 6 a shows a cross-sectional structure schematic diagram of a third cover film provided by the present embodiment, Figure 6 b shows a plane structure schematic diagram of the third cover film provided by the present embodiment.

[0053] Referring to Figure 4 or Figure 6 When the number of flow guide grooves 3030 is multiple, the multiple flow guide grooves 3030 can be arranged at equal intervals and in parallel. That is, the multiple flow guide grooves 3030 are uniformly distributed on the surface of the cover film 303 close to the glue film 302. In this way, the overflow glue of the glue film 302 can be sufficiently and uniformly guided to the periphery of the second edge 30b, thereby reducing the overflow glue amount of the soft board area 31 and reducing the design size of the printed circuit board.

[0054] In an optional implementation, referring to Figure 4 and Figure 5 , the extension direction of the flow guide groove 3030 can be parallel to the junction line of the hard board area 30 and the soft board area 31, so that on the one hand, the process difficulty of slotting can be reduced, and on the other hand, the flow channel of the overflow glue can be ensured to be unobstructed, and the overflow glue amount of the soft board area 31 is reduced as much as possible, and the reserved overflow glue space of the printed circuit board is reduced.

[0055] In another optional implementation, referring to Figure 6 , the flow guide groove 3030 can include a first groove 61 and a second groove 62 that are in communication with each other, wherein the extension direction of the first groove 61 is parallel to the junction line of the hard board area 30 and the soft board area 31, and the second groove 62 is bent towards the junction line. The shape of the second groove 62 can be, for example, semicircular, V-shaped, etc., which is not limited in the present application.

[0056] When the shape of the hard board area 30 is a quadrilateral, the junction line of the hard board area 30 and the soft board area 31 is the first side edge a1 or the second side edge a2.

[0057] It should be noted that the shape of the flow guide groove 3030 is not limited to the shapes shown in Figure 4 , Figure 5 and Figure 6 , and the specific shape of the flow guide groove 3030 is not limited in the present embodiment.

[0058] In order to avoid the overflow glue in the flow guide groove 3030 flowing to the soft board area 31, referring to Figure 4 , the distance d1 between the flow guide groove 3030 and the junction line or the soft board area 31 can be greater than or equal to 1 mm. Wherein, the junction line is the junction line of the hard board area 30 and the soft board area 31.

[0059] It should be noted that in the embodiments of the present application, as shown in Figure 4 , the distance d1 between the flow guide groove 3030 and the junction line is the minimum distance between the flow guide groove 3030 and the junction line, that is, the shortest distance between the flow guide groove 3030 and the junction line.

[0060] In an optional implementation, referring to Figure 4 , the depth d2 of the flow guide groove 3030 can be less than or equal to half the thickness of the cover film 303. In this way, the complete coverage of the cover film 303 to the first metal layer 304 can be ensured, the first metal layer 304 is protected from corrosion, and the risk of exposure of the first metal layer 304 due to the thickness of the cover film 303 being too thin in the flow guide groove 3030 area is avoided.

[0061] In specific implementations, the depth d2 of the flow guide groove 3030 may, for example, be greater than or equal to 2 μm and less than or equal to 10 μm, and may be set according to actual requirements. The present embodiment does not limit this.

[0062] It should be noted that the depth of the flow guide groove 3030 refers to the dimension of the flow guide groove 3030 in the direction perpendicular to the substrate 301.

[0063] In specific implementations, as shown in Figures 4 to 6 the projection of the slot opening of the flow guide groove 3030 on the substrate 301 covers the projection of the slot bottom of the flow guide groove 3030 on the substrate 301. That is, the opening of the flow guide groove 3030 away from the substrate 301 is greater than the opening of the flow guide groove 3030 close to the substrate 301. In this way, the flow guide groove 3030 can accommodate more glue overflow, and can minimize the influence of the flow guide groove 3030 on the first metal layer 304. For example, the shape of the cross section of the flow guide groove 3030 perpendicular to the extension direction may be semicircular, V-shaped, inverted trapezoidal, etc. The present embodiment does not limit this.

[0064] In specific implementations, referring to Figure 4 in the direction perpendicular to the extension direction of the flow guide groove 3030, the slot opening width d3 of the flow guide groove 3030 may be greater than or equal to 0.5 mm and less than or equal to 1 mm. The slot opening width of the flow guide groove 3030 may be determined according to the number of flow guide grooves 3030, the thickness of the glue film 302, and the size of the cover film 303, etc. The present embodiment does not limit this.

[0065] In the present embodiment, the specific shape, position, and relative position relationship of each structure in the printed circuit board can be designed as needed. In actual processes, due to the limitation of process conditions or other factors, some deviations may also occur. Therefore, as long as the shape, position, and relative position relationship of each structure in the printed circuit board generally meet the above conditions, it belongs to the printed circuit board provided by the present embodiment.

[0066] An embodiment of the present application also provides a display device, which comprises a display panel and a printed circuit board as described in any embodiment connected with the display panel.

[0067] In specific implementations, the display panel and the printed circuit board can be directly connected or indirectly connected, which can be determined according to the packaging mode of the display panel, etc. The present application does not limit this.

[0068] In an optional implementation, the packaging mode of the display panel is COP (chip on plastic), and the printed circuit board can be directly connected with the binding area of the display panel.

[0069] In another alternative implementation, the display panel is packaged in a COG (chip on glass) manner, and the printed circuit board can be directly connected to the bonding area of the display panel.

[0070] In yet another alternative implementation, the display panel is packaged in a COF (chip on film) manner, and the display device can further include a chip on film, and the printed circuit board is connected to the display panel through the chip on film. Specifically, one end of the chip on film is connected to the bonding area of the display panel, and the other end is connected to the printed circuit board.

[0071] It should be noted that the display device in the present embodiment can be any product or component having 2D or 3D display function, such as electronic paper, mobile phone, tablet computer, television, notebook computer, digital photo frame, navigator, etc.

[0072] An embodiment of the present application further provides a preparation method of a printed circuit board, the printed circuit board including a hard board area 30 and a soft board area 31, as shown in Figure 3 The soft board area 31 is located at the periphery of the first edge 30a of the hard board area 30; the preparation method of the printed circuit board of the hard board area 30 includes the following steps.

[0073] Step 701: providing a substrate 301.

[0074] Step 702: sequentially attaching a glue film 302, a cover film 303 and a first metal layer 304 to one side of the substrate 301, wherein the cover film 303 is provided with a flow guide groove 3030 on the side surface close to the glue film 302, the flow guide groove 3030 extends to the second edge 30b of the hard board area 30, and the flow guide groove 3030 is used to guide the overflow of the glue film 302 to the peripheral area of the second edge 30b.

[0075] Step 703: cutting along the second edge 30b to cut off the peripheral area of the second edge 30b, to obtain a printed circuit board.

[0076] The preparation method provided in the present embodiment can be used to prepare the printed circuit board provided in any of the above embodiments, and the structure and effects of the printed circuit board can refer to the foregoing embodiments, which will not be described here.

[0077] The embodiment of the present application provides a printed circuit board, a preparation method thereof and a display device, wherein the printed circuit board comprises a hard board area 30 and a soft board area 31, the soft board area 31 is located at the periphery of a first edge 30a of the hard board area 30; the printed circuit board of the hard board area 30 comprises a substrate 301, and a film 302, a cover film 303 and a first metal layer 304 which are stacked on one side of the substrate 301, the film 302 is arranged close to the substrate 301, wherein the cover film 303 is provided with a flow guide groove 3030 on the surface of the side close to the film 302, and the flow guide groove 3030 extends to a second edge 30b of the hard board area 30. According to the technical scheme of the present application, the flow guide groove 3030 is arranged on the surface of the side of the cover film 303 close to the film 302, and the flow guide groove 3030 extends to the second edge 30b of the hard board area 30, so that in the process of laminating and pressing the first metal layer 304, the overflow glue of the film 302 can be effectively guided to the periphery of the second edge 30b of the hard board area 30 through the flow guide groove 3030, since the soft board area 31 is located at the periphery of the first edge 30a of the hard board area 30, therefore, the present scheme can effectively reduce the overflow glue flowing to the soft board area 31, reduce the overflow glue amount of the soft board area 31, and then the reserved overflow glue space of the soft board area 31 can be reduced, the design size of the printed circuit board is effectively reduced, the demand of the terminal for the compact space of the display module is met, and the compactness of the display device is improved.

[0078] Each embodiment in the specification is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between the embodiments can be referred to each other.

[0079] Finally, it should be noted that in this document, relationship terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, product or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, product or equipment. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, product or equipment including the element.

[0080] The printed circuit board, the preparation method thereof and the display device provided by the present application are described in detail above, and the principles and implementation manners of the present application are described by using specific examples. The above description of the examples is only used to help understand the method of the present application and the core idea thereof. Meanwhile, for those skilled in the art, the specific implementation manners and application ranges will be changed according to the idea of the present application. In conclusion, the content of the present description should not be understood as a limitation of the present application.

Claims

1. A printed circuit board, characterized in that The printed circuit board includes a hard board area and a soft board area, wherein the soft board area is located at the periphery of the first edge of the hard board area; The printed circuit board in the hard board area includes a substrate, and an adhesive film, a cover film, and a first metal layer stacked on one side of the substrate, the adhesive film being arranged close to the substrate, and a guide groove being arranged on a surface of the cover film close to the adhesive film, the guide groove extending to the second edge of the hard board area; The adhesive film is formed by curing a semi-cured insulating film.

2. The printed circuit board according to claim 1, wherein The shape of the hard plate area is a quadrilateral, the first edge includes a first side of the hard plate area and a second side opposite to the first side, the second edge includes a third side of the hard plate area and a fourth side opposite to the third side, one end of the guide groove extends to the third side, and the other end extends to the fourth side.

3. The printed circuit board according to claim 1 or 2, characterized in that: There are multiple guide grooves, and the guide grooves are evenly spaced and arranged in parallel.

4. The printed circuit board according to claim 1 or 2, characterized in that: The extension direction of the guide groove is parallel to the boundary line between the hard board area and the soft board area.

5. The printed circuit board according to claim 1 or 2, characterized in that: The guide groove includes a first groove and a second groove connected to each other, wherein the extension direction of the first groove is parallel to the boundary line between the hard board area and the soft board area, and the second groove is bent toward the boundary line.

6. The printed circuit board according to claim 1 or 2, characterized in that: The distance between the guide groove and the soft board area is greater than or equal to 1 mm.

7. The printed circuit board according to claim 1 or 2, characterized in that: The depth of the guide groove is less than or equal to half the thickness of the covering film.

8. The printed circuit board according to claim 1 or 2, characterized in that: The depth of the guide groove is greater than or equal to 2 μm and less than or equal to 10 μm.

9. The printed circuit board according to claim 1 or 2, characterized in that: The orthographic projection of the opening of the guide groove on the substrate covers the orthographic projection of the groove bottom of the guide groove on the substrate.

10. The printed circuit board according to claim 1 or 2, characterized in that: In an extension direction perpendicular to the guide groove, a slot width of the guide groove is greater than or equal to 0.5 mm and less than or equal to 1 mm.

11. The printed circuit board according to claim 1 or 2, characterized in that: The material of the cover film includes polyimide.

12. The printed circuit board according to claim 1 or 2, characterized in that: The adhesive film, the covering film and the first metal layer are symmetrically arranged on both sides of the substrate, and a solder resist layer is further arranged on a side of the first metal layer away from the substrate.

13. A display device, characterized in that: The display device includes a display panel and a printed wiring board according to any one of claims 1 to 12 connected to the display panel.

14. The display device according to claim 13, wherein: The display device further includes a chip-on-film (COF), and the printed circuit board and the display panel are connected via the COF.

15. A method for preparing a printed circuit board, characterized in that: The printed circuit board includes a hard board area and a soft board area, wherein the soft board area is located at the periphery of the first edge of the hard board area; The method for preparing the printed circuit board in the hard board area includes: providing a substrate; An adhesive film, a cover film, and a first metal layer are sequentially laminated on one side of the substrate, wherein a guide groove is provided on a surface of the cover film on a side close to the adhesive film, the guide groove extending to the second edge of the hard board area, and the guide groove is used to guide adhesive overflow from the adhesive film to a peripheral area of ​​the second edge; cutting along the second edge to cut off the peripheral area of ​​the second edge to obtain the printed circuit board; The adhesive film is formed by curing a semi-cured insulating film.

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