A flexible circuit board, a display device and a method for manufacturing the same

Abstract

The embodiment of the present invention discloses a flexible circuit board, a display device and a method for preparing the same. In a specific embodiment, the flexible circuit board includes a circuit board body and a fingerprint module; the circuit board body includes a recessed area corresponding to the fingerprint module, and at least part of the fingerprint module is fixed in the recessed area; the fingerprint module is welded to the circuit board body through a transfer circuit board to achieve electrical connectivity. This embodiment achieves electrical connectivity by welding the fingerprint module and the circuit board body, that is, the flexible circuit board and the fingerprint module are designed as an integrated whole, thereby effectively avoiding the unreliability of traditional ZIF connection or BTB connection, and increasing the connection reliability of the fingerprint module and the whole system of the display device; at the same time, the signal transmission quality can be guaranteed, and the manufacturing cost of the display device can be effectively reduced.

Description

Technical Field

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

[0002] With the development of display technology, under-screen fingerprint technology has been widely used due to its advantages such as ultra-high screen-to-body ratio and efficient fingerprint recognition, and has now become a standard feature of mainstream smartphones. Usually, in order to better meet the user's habit of using smart devices, the fingerprint module is usually set at the bottom of the display device.

[0003] As for the flexible OLED display device, the lower end of the display device is the wiring area of ​​the flexible printed circuit (FPC) of the display panel. In the prior art, in order to meet the use of the fingerprint module, the usual design is to open a hole at the position of the flexible printed circuit board corresponding to the fingerprint film group, and place the fingerprint module into the hole. The fingerprint module is usually directly connected to the overall system of the display device through a ZIF (Zero Insertion Force) plug-in method, or connected to the flexible printed circuit board of the display panel through a ZIF plug-in method, and then connected to the entire system of the display device through the flexible printed circuit board. However, the ZIF connection method in the prior art is relatively expensive and has poor signal transmission quality. In addition, in the drop test of the entire display device, there is a risk of the ZIF connector detaching and falling, which affects the reliability of the display device. Summary of the invention

[0004] An object of the present invention is to provide a flexible circuit board, a display device and a method for manufacturing the same, so as to solve at least one of the problems existing in the prior art.

[0005] In order to achieve at least one of the above purposes, the present invention adopts the following technical solutions:

[0006] A first aspect of the present invention provides a flexible circuit board, comprising:

[0007] Circuit board body and fingerprint module;

[0008] The circuit board body includes a recessed area corresponding to the fingerprint module, and at least a portion of the fingerprint module is fixed in the recessed area;

[0009] The fingerprint module is welded to the circuit board body via a transfer circuit board to achieve electrical connection.

[0010] The flexible circuit board provided in the first aspect of the present invention electrically connects the fingerprint module to the circuit board body by welding the fingerprint module through the soldering pad and the adapter circuit board, that is, the flexible circuit board and the fingerprint module are designed as an integrated whole, thereby effectively avoiding the unreliability of the traditional ZIF connection or BTB (Board to Board) connection, preventing the connection between the fingerprint module and the whole system or the fingerprint module and the flexible circuit board from falling off during the reliability test such as the whole display device falling, increasing the connection reliability between the fingerprint module and the whole display device system, and improving the test yield rate of the display device equipped with the flexible circuit board; at the same time, connecting the fingerprint module and the flexible circuit board through the soldering pad can effectively improve the signal transmission quality, and at the same time can also reduce the connection cost of the fingerprint module and the flexible circuit board.

[0011] Optionally, the adapter circuit board is a flexible adapter circuit board.

[0012] This optional implementation adopts a flexible adapter circuit board to connect the fingerprint module and the circuit board body, which can be applicable to fingerprint modules and circuit board bodies of different shapes, heights or flatnesses, thereby improving the application range of the flexible circuit board.

[0013] Optionally, the recessed area is a groove or a through hole.

[0014] Optionally, the recessed area is a through hole penetrating the circuit board body;

[0015] The circuit board body includes a first body portion and a second body portion located at two opposite sides of the recessed area;

[0016] The flexible circuit board includes a bridge circuit board electrically connecting the first body portion and the second body portion;

[0017] The bridge circuit board is welded to the circuit board body to achieve electrical connection.

[0018] This optional implementation is achieved by providing a bridge circuit board that electrically connects the first body part and the second body part and welding it to the circuit board body. That is, under the premise of ensuring that the thickness of the display device meets the requirements of lightness and thinness, a bridge circuit board is added in the upper space of the fingerprint module (i.e., above the recessed area of ​​the flexible circuit board) for bridge routing, which greatly increases the routing space of the flexible circuit board and increases the routing space of the flexible circuit board by about 20-30%. That is to say, under the same line data, this embodiment can effectively reduce the thickness of the flexible circuit board, reduce the size of the board frame, and thus reduce the overall production cost of the product by providing a bridge circuit board. Furthermore, the bridge circuit board of this embodiment can also separate the routing of signals that are susceptible to interference, reduce the mutual interference between routing signals, thereby increasing the routing continuity of the flexible circuit board and improving the anti-interference ability of the signal.

[0019] Optionally, the orthographic projection of the bridge circuit board on the circuit board body covers the recessed area.

[0020] This optional implementation can effectively block the gap between the fingerprint module and the recessed area, thereby improving the assembly yield of the fingerprint module.

[0021] Optionally, the bridge circuit board is a printed bridge circuit board or a flexible bridge circuit board.

[0022] This optional implementation manner sets the bridge circuit board as a printed bridge circuit board or a flexible bridge circuit board, so that the flexible circuit board of this implementation manner can be applied to more different situations, that is, according to different situations (such as the situation where the thickness of the fingerprint module is larger, or the thickness of the flexible circuit board is smaller, or the situation where the thickness of the fingerprint module is smaller and the thickness of the flexible circuit board is larger), a printed bridge circuit board or a flexible bridge circuit board is selected to achieve bridging and routing of the bridge circuit board in the space above the fingerprint module, and at the same time, mutual interference between the bridge circuit board and the fingerprint module located in the recessed area can be avoided.

[0023] The second aspect of the present invention provides a method for preparing a flexible circuit board as provided in the first aspect of the present invention, comprising:

[0024] A recessed area corresponding to the fingerprint module is formed on the circuit board body;

[0025] Fixing at least a portion of the fingerprint module in the recessed area;

[0026] The fingerprint module and the circuit board body are welded via a transfer circuit board to achieve electrical connectivity.

[0027] Compared with the prior art, the method for preparing the flexible circuit board provided in the second aspect of the present invention provides sufficient flatness for the fingerprint module and the circuit board body, can realize the welding of the circuit board body and the fingerprint module, and effectively improve the efficiency of fingerprint module welding.

[0028] A third aspect of the present invention provides a display device, comprising a display panel, a heat dissipation layer located on the display panel, and the flexible circuit board provided by the first aspect of the present invention;

[0029] An opening area corresponding to the recessed area is provided in the heat dissipation layer;

[0030] The flexible circuit board is attached to a side of the display panel away from the light-emitting side through the heat dissipation layer;

[0031] Part of the fingerprint module is located in the opening area of ​​the heat dissipation layer.

[0032] Optionally, the recessed area is a through hole penetrating the circuit board body;

[0033] The circuit board body includes a first body portion and a second body portion located at two opposite sides of the recessed area;

[0034] The flexible circuit board includes a bridge circuit board electrically connecting the first body portion and the second body portion;

[0035] The bridge circuit board is welded to the circuit board body to achieve electrical connection;

[0036] The bridge circuit board is located at a side of the circuit board body away from the display panel.

[0037] Optionally, the orthographic projection of the bridge circuit board on the circuit board body covers the recessed area;

[0038] The fingerprint module is located in a space formed by an opening area of ​​the heat dissipation layer, a recessed area of ​​the circuit board body, the bridge circuit board and the display panel.

[0039] This optional implementation can effectively block the gap between the fingerprint module and the circuit board body, improve the assembly yield of the fingerprint module, and avoid the light leakage phenomenon caused by the bonding method of the fingerprint module in the existing display device, thereby improving the quality of the display device and enhancing the user experience.

[0040] A fourth aspect of the present invention provides a method for preparing the display device provided in the third aspect of the present invention, comprising:

[0041] forming a heat dissipation layer on the display panel;

[0042] forming an opening area corresponding to the recessed area in the heat dissipation layer;

[0043] The flexible circuit board is attached to a side of the display panel away from the light-emitting side through the heat dissipation layer, so that part of the fingerprint module is located in the opening area of ​​the heat dissipation layer.

[0044] The beneficial effects of the present invention are as follows:

[0045] In view of the technical problems existing in the prior art, an embodiment of the present invention provides a flexible circuit board, a display device and a preparation method thereof. The flexible circuit board of this embodiment realizes electrical connection between a fingerprint module and a circuit board body by welding the fingerprint module through a soldering pad and a transfer circuit board, that is, the flexible circuit board and the fingerprint module are designed as an integrated whole, thereby effectively avoiding the unreliability of traditional ZIF connection or BTB (Board to Board) connection, preventing the connection between the fingerprint module and the whole system or the fingerprint module and the flexible circuit board from falling off during reliability tests such as the whole display device falling, thereby increasing the connection reliability between the fingerprint module and the whole display device system, and improving the test yield rate of the display device equipped with the flexible circuit board; at the same time, connecting the fingerprint module and the flexible circuit board through the soldering pad can effectively improve the signal transmission quality, and at the same time can also reduce the connection cost of the fingerprint module and the flexible circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0047] Figure 1 A schematic structural diagram of a flexible circuit board in an embodiment of the present invention is shown.

[0048] Figure 2 A structural cross-sectional view of a flexible circuit board in one embodiment of the present invention is shown.

[0049] Figure 3 A structural cross-sectional view of a flexible circuit board in one embodiment of the present invention is shown.

[0050] Figure 4 A structural cross-sectional view of a flexible circuit board in one embodiment of the present invention is shown.

[0051] Figure 5 A flowchart of preparing a flexible circuit board in one embodiment of the present invention is shown.

[0052] Figure 6 A rear view showing the structure of a display device in one embodiment of the present invention.

[0053] Figure 7 A cross-sectional view of a structure in which a flexible circuit board and a display panel are bonded together in a display device according to an embodiment of the present invention is shown.

[0054] Figure 8 A cross-sectional view of a structure in which a flexible circuit board and a display panel are bonded together in a display device according to an embodiment of the present invention is shown.

[0055] Fig. 9 A cross-sectional view of a structure in which a flexible circuit board and a display panel are bonded together in a display device according to an embodiment of the present invention is shown.

[0056] Fig.10 A flowchart of manufacturing a display device in one embodiment of the present invention is shown. DETAILED DESCRIPTION

[0057] In the description of the present invention, it should be noted that the terms "upper", "lower", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0058] It should be noted that, although the terms "first", "second", etc. may be used herein to describe various parts, components, elements, regions, layers and / or parts, these parts, components, elements, regions, layers and / or parts should not be limited by these terms. Instead, these terms are used to distinguish one part, component, element, region, layer and / or part from another. Thus, for example, the first part, first member, first element, first region, first layer and / or first part discussed below may be referred to as the second part, second member, second element, second region, second layer and / or second part without departing from the teachings of the present invention.

[0059] It should also be noted that, in the description of the present invention, 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 "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article 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, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0060] In addition, in the prior art, a hole is opened at a position of the flexible circuit board corresponding to the fingerprint module, and the hole position is generally located at the center of the flexible circuit board, so that the routing of the flexible circuit board needs to bypass the opening area, affecting the continuity of the routing of the flexible circuit board and reducing the routing space of the flexible circuit board, so that the flexible circuit board requires a larger routing space or more routing layers.

[0061] In addition, the inventors found that in the design scheme of the prior art, the fingerprint module needs to be placed in the opening of the flexible circuit board and attached to the display panel after the flexible circuit board is bonded and fixed to the display panel through a heat dissipation film, which results in the flatness of the plane where the fingerprint module is located being low, making it difficult to operate on the fingerprint module. At the same time, the connector between the fingerprint module and the flexible circuit board or the fingerprint module and the entire system is easy to fall off.

[0062] Furthermore, for a flexible multi-layer touch display device (FMLOC, Flexible Multi-Layer OnCell), the signal driving electrode T of the touch unit x and the sensing electrode R x The wiring needs to be connected on the flexible circuit board, and the driving electrode T x and the sensing electrode R x Located on the left and right sides of the flexible circuit board respectively, the openings on the flexible circuit board will also affect the wiring continuity of the touch unit.

[0063] In view of the technical problems existing in the prior art, an embodiment of the present invention provides a flexible circuit board 100, which includes a circuit board body 110 and a fingerprint module 120. The circuit board body 110 includes a recessed area 111 corresponding to the fingerprint module 120. Figure 1 As shown, the recessed area 111 is located at the center of the circuit board body 110, and the cross-sectional shape of the recessed area 111 is rhombus-shaped. In some specific examples, the cross-sectional shape of the recessed area 111 may be, for example, circular or rectangular, and the shape of the recessed area 111 may be adaptively adjusted according to the shape of the fingerprint module 120. At least a portion of the fingerprint module 120 is fixed in the recessed area 111. In a specific example, the size of the fingerprint module 120 is slightly smaller than the size of the recessed area 111, and the fingerprint module 120 is fixed to the inner side of the recessed area 111 by bonding or other methods well known to those skilled in the art, so as to achieve the connection and fixation between the fingerprint module 120 and the circuit board body 110, such as Figure 2-4 shown.

[0064] In this embodiment, the fingerprint module 120 is welded to the circuit board body 110 through the adapter circuit board 130 to achieve electrical connectivity. In a specific example, the adapter circuit board 130 is respectively welded to the fingerprint module 120 and the circuit board body 110 through the pads, so as to achieve signal transmission between the fingerprint module 120 and the circuit board body 110. This embodiment combines and fixes the fingerprint module 120 in the recessed area 111 in advance, so that the plane where the fingerprint module 120 is located has a higher flatness compared to the design scheme of the prior art, making it possible to weld the fingerprint module 120 to the circuit board body 110 through the adapter circuit board 130 and the pads to achieve electrical connectivity, thereby improving the connection reliability between the fingerprint module 120 and the circuit board body 110.

[0065] In one specific example, the fingerprint module 120 includes a fingerprint sensor (Finger Print Sensor, FPS) and other necessary components for implementing the fingerprint recognition function. In another specific example, the fingerprint module 120 may also include a fingerprint sensor FPS, a connector and a packaging component (including a frame glue and a light shielding tape, etc.).

[0066] In a specific example, the flexible circuit board 100 can be, for example, a main FPC (Main FPC, abbreviated as: MFPC) for driving the display, and the signal of the fingerprint module 120 can communicate with the main board of the display device 200 through the connector of the flexible circuit board 100, thereby realizing the fingerprint recognition function of the fingerprint module 120.

[0067] In a specific example, the flexible circuit board 100 is a multi-layer flexible circuit board, that is, the circuit board body 110 also includes multiple layers, so that the wiring is distributed in different layers of the flexible circuit board, increasing the wiring volume in the flexible circuit board 100, and the fingerprint module 120 can be welded in any layer of the circuit board body 110 through the adapter circuit board 130 and the pad. In a specific example, the fingerprint module 120 is electrically connected to the top layer of the circuit board body 110 by welding the adapter circuit board 130; in another specific example, the fingerprint module 120 can also be electrically connected to the bottom layer of the circuit board body 110 by welding the adapter circuit board 130.

[0068] The flexible circuit board 100 of this embodiment realizes electrical connection by welding the fingerprint module 120 to the circuit board body 110 through the soldering pad and the adapter circuit board 130, that is, the flexible circuit board 100 and the fingerprint module 120 are designed as an integrated whole, thereby effectively avoiding the unreliability of the traditional ZIF connection or BTB (Board to Board) connection, preventing the connection between the fingerprint module and the whole system or the fingerprint module and the flexible circuit board from falling off during the reliability test such as the whole display device falling, increasing the connection reliability of the fingerprint module 120 and the whole system of the display device 200, and improving the yield rate of the display device 200 equipped with the flexible circuit board 100; at the same time, connecting the fingerprint module 120 and the circuit board body 110 through the soldering pad can effectively improve the signal transmission quality, and at the same time can also reduce the connection cost of the fingerprint module 120 and the flexible circuit board 100.

[0069] In a possible implementation, the adapter circuit board 130 is a flexible adapter circuit board. Figure 2-4 As shown, part of the fingerprint module 120 is located in the recessed area 111 of the circuit board body 110, and part of the fingerprint module 120 protrudes outside the circuit board body 110, that is, the thickness of the fingerprint module 120 is different from the thickness of the circuit board body 110. This embodiment uses a flexible transfer circuit board to connect the fingerprint module 120 and the circuit board body 110, which can overcome the difference in shape, height or flatness between the fingerprint module 120 and the circuit board body 110, ensure effective welding of the fingerprint module 120 and the circuit board body 110, and is suitable for fingerprint modules 120 and circuit board bodies 110 of different shapes, heights or flatness, thereby improving the application range of the flexible circuit board 100.

[0070] In a possible implementation, the recessed area 111 is a groove or a through hole. For example, the recessed area 111 is a groove formed by being recessed inward from one side surface of the circuit board body 110 , or the recessed area 111 is a through hole that passes through the circuit board body 110 .

[0071] In a possible implementation, the recessed area 111 is a through hole penetrating the circuit board body 110. Figure 2-3 As shown, the circuit board body 110 includes a first body portion 112 and a second body portion 113 located at two opposite sides of the recessed area 111. For example, the first body portion 112 and the second body portion 113 may be located at the left and right sides of the recessed area 111, or located at the upper and lower sides of the recessed area 111. The flexible circuit board 100 includes a bridge circuit board 140 that electrically connects the first body portion 112 and the second body portion 113. The bridge circuit board 140 is located above the transfer circuit board 130. The bridge circuit board 140 is welded to the circuit board body 110 through a pad to achieve electrical connection.

[0072] This implementation method combines and fixes the fingerprint module 120 in the recessed area 111 in advance, and then forms a bridge circuit board 140 in the space above the fingerprint module 120. Compared with the design scheme of the prior art (after the fingerprint module and the display panel are attached and fixed, a bridge circuit board cannot be formed above the fingerprint module), the plane where the fingerprint module 120 is located has a higher flatness, making it possible to form a transfer circuit board 130 in the space above the fingerprint module 120 and weld it to the circuit board body 110 through the soldering pad.

[0073] In a specific example, if Figure 2-3 As shown, the bridge circuit board 140 is located in the upper space of the fingerprint module 120, and the orthographic projection of the bridge circuit board 140 on the circuit board body 110 covers the orthographic projection of the adapter circuit board 130 on the circuit board body 110. In another specific example, the orthographic projection of the bridge circuit board on the circuit board body does not cover the orthographic projection of the adapter circuit board on the circuit board body.

[0074] This implementation method provides a bridge circuit board 140 that electrically connects the first body part 112 and the second body part 113 and welds it to the circuit board body 110, that is, under the premise of ensuring that the thickness of the display device 200 meets the requirements of lightness and thinness, a bridge circuit board 140 is added to the upper space of the fingerprint module 120 (i.e., the position above the recessed area 111 of the flexible circuit board 100) for bridge routing, which greatly increases the routing space of the flexible circuit board 100, and increases the routing space of the flexible circuit board 100 by about 20-30%. That is to say, under the condition of the same line data, this embodiment can effectively reduce the thickness of the flexible circuit board 100 and the size of the board frame by providing the bridge circuit board 140, thereby reducing the overall production cost of the product. Furthermore, the bridge circuit board 140 of this embodiment can also separate the signals susceptible to interference and reduce the mutual interference between the routing signals, thereby increasing the routing continuity of the flexible circuit board 100 and improving the anti-interference ability of the signal.

[0075] In a specific example, if Figure 4As shown, the recessed area 111 is a groove formed by inward depression from one side surface of the circuit board body 110. For example, the flexible circuit board 100 of this embodiment is a multi-layer flexible circuit board, and a groove (i.e., a blind hole) is made in the bottom layer of the circuit board body 110, and the fingerprint module 120 is fixed in the groove. The fingerprint module 120 is still welded on the circuit board body 110 through the adapter circuit board 130 and the pad, and can be welded in any layer of the circuit board body 110 according to actual conditions; at the same time, the blind hole does not penetrate the top layer of the circuit board body 110, that is, the top layer of the circuit board body 110 is not opened, and normal routing can still be performed. According to actual industrial design requirements, the top layer of the circuit board body 110 can be designed with a single-layer or double-layer routing, thereby increasing the routing amount in the flexible circuit board 100, increasing the routing space in the flexible circuit board 100, and improving the stability of signal transmission. In addition, there is no need to additionally set up a bridge circuit board and a pad for welding the bridge circuit board on the circuit board body, which further saves production costs. This specific example is applicable to the case where the thickness of the fingerprint module 120 is relatively small, and the flexible circuit board 100 has more layers and a larger thickness.

[0076] In a possible implementation, the bridge circuit board 140 is a printed bridge circuit board or a flexible bridge circuit board. Figure 2 In the example shown, the top surface of the fingerprint module 120 is flush with the top surface of the circuit board body 110, that is, the top surface of the fingerprint module 120 does not protrude from the top surface of the circuit board body 110, and the bridge circuit board 140 is a printed bridge circuit board; in another specific example, Figure 3 As shown, the thickness of the fingerprint module 120 is relatively large, or the thickness of the circuit board body 110 is small, the top surface and the bottom surface of the fingerprint module 120 both protrude from the surface of the circuit board body 110, and the bridge circuit board 140 located above the fingerprint module 120 can be, for example, a flexible bridge circuit board with a certain flexibility, which can cross the wiring from above the fingerprint module 120 without interfering with the fingerprint module 120.

[0077] This implementation sets the bridge circuit board 140 as a printed bridge circuit board or a flexible bridge circuit board, so that the flexible circuit board 100 of this embodiment can be applied to more different situations, that is, a printed bridge circuit board or a flexible bridge circuit board is selected according to different situations to realize the bridge circuit board 140 to bridge and route in the space above the fingerprint module 120, and at the same time, it can also avoid the bridge circuit board 140 from interfering with the fingerprint module 120 located in the recessed area 111.

[0078] In a possible implementation, the orthographic projection of the bridge circuit board 140 on the circuit board body 110 covers the recessed area 111, that is, Figure 1As shown, the bridge circuit board 140 covers the recessed area 111 and the fingerprint module 120 located in the recessed area 111. It is understandable that in order to facilitate the fitting of the fingerprint module 120, the size of the recessed area 111 is usually larger than the size of the fingerprint module 120. In this way, due to the gap between the fingerprint module 120 and the inner side of the recessed area 111, the display device 200 loaded with the flexible circuit board 100 is prone to light leakage. Through this embodiment, the bridge circuit board 140 covers the recessed area 111 and the fingerprint module 120, thereby effectively blocking the gap between the fingerprint module 120 and the recessed area 111, thereby preventing the light leakage of the display device 200 and improving the assembly yield of the fingerprint module 120.

[0079] Another embodiment of the present invention provides a method for preparing the flexible circuit board 100 provided in the above embodiment, as shown in FIG. Figure 5 As shown, the following steps are included:

[0080] S110, forming a recessed area 111 corresponding to the fingerprint module 120 on the circuit board body 110;

[0081] In a specific example, the recessed area 111 may be a groove or a through hole, and may be designed according to the actual thickness of the fingerprint module 120. In another specific example, the cross-sectional shape of the recessed area 111 may be, for example, a diamond, a circle, or a rectangle.

[0082] S120, fixing at least a portion of the fingerprint module 120 in the recessed area 111;

[0083] In a specific example, at least a portion of the fingerprint module 120 is fixed in the recessed area 111 by bonding or other methods well known to those skilled in the art, so as to achieve connection and fixation between the fingerprint module 120 and the circuit board body 110 .

[0084] S130 , soldering the fingerprint module 120 and the circuit board body 110 via the adapter circuit board 130 to achieve electrical connectivity.

[0085] In a specific example, the adapter circuit board 130 is respectively soldered to the fingerprint module 120 and the circuit board body 110 through solder pads, thereby realizing signal transmission between the fingerprint module 120 and the circuit board body 110 .

[0086] Compared with the prior art, the preparation method of the flexible circuit board of this embodiment can provide sufficient flatness for the fingerprint module 120 and the circuit board body 110, thereby realizing welding between the circuit board body 110 and the fingerprint module 120, effectively improving the welding efficiency of the fingerprint module 120, and improving the connection reliability between the fingerprint module 120 and the circuit board body 110.

[0087] In a possible implementation, the recessed area 111 is a through hole penetrating the circuit board body 110 , and the circuit board body 110 includes a first body portion 112 and a second body portion 113 located on two opposite sides of the recessed area 111 .

[0088] After step S130, the method further includes:

[0089] S140, soldering the bridge circuit board 140 to the circuit board body 110 through the soldering pad to achieve electrical connection, wherein the bridge circuit board 140 is used to electrically connect the first body part 112 and the second body part 113, thereby forming the bridge circuit board 140 located above the fingerprint module 120.

[0090] Another embodiment of the present invention provides a display device 200, such as Figure 6-9 As shown, the display panel 210, the heat dissipation layer 220 located on the side of the display panel 210 away from the light emitting side, and the flexible circuit board 100 provided in the above embodiment. Figure 7-9 As shown by the arrow in . The heat dissipation layer 220 is provided with an opening area 221 corresponding to the recessed area 111 ; the flexible circuit board 100 is attached to the side of the display panel 210 away from the light-emitting side through the heat dissipation layer 220 ; and part of the fingerprint module 120 is located in the opening area 221 of the heat dissipation layer 220 .

[0091] The display device 200 provided in this embodiment is a display device 200 in which a fingerprint module 120 is integrated on the back of a display panel 210. By setting the fingerprint module 120 on the back of the display panel 210, under-screen fingerprint recognition and full-screen display can be realized. Generally, in order to realize various functions of the display device 200, various flexible circuit boards 100 can be fixed to the display panel 210 through a bonding process, and then the flexible circuit board 100 is bent, and the flexible circuit board 100 is attached to the heat dissipation layer 220 on the back of the display panel 210, that is, the side of the display panel 210 away from the light-emitting side, and the connector of the flexible circuit board 100 can be coupled to the main board of the display panel 210 to realize the corresponding functions.

[0092] In a specific example, the display device 200 is an OLED (Organic Light-Emitting Diode) flexible display device. The OLED flexible display device 200 can be, for example, electronic paper, a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, a navigator, or any other product or component with a display function, which is not limited in this embodiment. In another specific example, the heat dissipation layer 220 can be, for example, a heat dissipation film (Super Clean Foam, abbreviated as SCF) with an adhesion effect.

[0093] In a possible implementation, the recessed area 111 is a groove or a through hole. In a specific example, the recessed area 111 is a groove. Fig. 9 As shown, the groove is formed by being recessed inward from one side of the circuit board body 110 close to the heat dissipation layer 220, and the fingerprint module 120 is located in the groove, that is, the fingerprint module 120 is located in the space surrounded by the circuit board body 110, the heat dissipation layer 220 and the display panel 210. The recessed area 111 of this implementation does not penetrate the top layer of the circuit board body 110, that is, the top layer of the circuit board body 110 can still be routed normally, and the top layer of the circuit board body 110 can be designed with single-layer or double-layer routing according to actual industrial design requirements, thereby increasing the routing amount in the flexible circuit board 100, increasing the routing space in the flexible circuit board 100, and improving the stability of signal transmission.

[0094] In a possible implementation, the recessed area 111 is a through hole penetrating the circuit board body 110; Figure 7-8 As shown, the fingerprint module 120 is relatively thick, and the top surface and / or bottom surface of the fingerprint module 120 protrudes from the circuit board body 110. The circuit board body 110 includes a first body portion 112 and a second body portion 113 located on two opposite sides of the recessed area 111; the flexible circuit board 100 includes a bridge circuit board 140 that electrically connects the first body portion 112 and the second body portion 113; the bridge circuit board 140 is welded to the circuit board body 110 to achieve electrical connectivity; the bridge circuit board 140 is located on the side of the circuit board body 110 away from the display panel 210.

[0095] This implementation method provides a bridge circuit board 140 that electrically connects the first body part 112 and the second body part 113 and welds it to the circuit board body 110, and adds a bridge circuit board 140 in the space above the fingerprint module 120 (i.e., above the recessed area 111 of the flexible circuit board 100) for bridging wiring, which can greatly increase the wiring space of the flexible circuit board 100, increase the wiring space of the flexible circuit board 100 by about 20-30%, and improve the continuity of the flexible circuit board 100; in a specific example, the display device 200 is a flexible multi-layer touch display device, and the provision of the bridge circuit board 140 in this implementation method can also improve the wiring continuity of the touch unit.

[0096] In a possible implementation, the orthographic projection of the bridge circuit board 140 on the circuit board body 110 covers the recessed area 111; Figure 6As shown, the bridge circuit board 140 covers the recessed area 111 and the fingerprint module 120 located in the recessed area 111. The fingerprint module 120 is located in the space formed by the opening area 221 of the heat dissipation layer 220, the recessed area 111 of the circuit board body 110, the bridge circuit board 140 and the display panel 210.

[0097] In this implementation, the fingerprint module 120 is housed in a closed space surrounded by the opening area 221 of the heat dissipation layer 220, the recessed area 111 of the circuit board body 110, the bridge circuit board 140 and the display panel 210. The bridge circuit board 140 can effectively block the gap between the fingerprint module 120 and the circuit board body 110, thereby improving the assembly yield of the fingerprint module 120 and avoiding light leakage caused by the bonding method of the fingerprint module, thereby improving the quality of the display device 200 and enhancing the user experience.

[0098] Another embodiment of the present invention provides a method for preparing the display device 200 provided in the above embodiment, as shown in FIG. Fig.10 As shown, including:

[0099] S210 , forming a heat dissipation layer 220 on the display panel 210 .

[0100] In a specific example, a heat dissipation layer 220 is attached to a surface of the display panel 210 that is away from the light emitting side. The heat dissipation layer 220 may be, for example, a heat dissipation film with an adhesive effect.

[0101] S220 , forming an opening area 221 corresponding to the recessed area 111 in the heat dissipation layer 220 , so as to facilitate alignment with the fingerprint module 120 and improve the manufacturing efficiency of the display device 200 .

[0102] S230 , attaching the flexible circuit board 100 to a side of the display panel 210 away from the light-emitting side through the heat dissipation layer 220 , so that part of the fingerprint module 120 is located in the opening area 221 of the heat dissipation layer 220 .

[0103] In a possible implementation, step S230 further includes:

[0104] S231 , connecting the flexible circuit board 100 to the display panel 210 to achieve signal conduction.

[0105] In a specific example, the bonding portion of the flexible circuit board 100 can be bonded to the display panel 210 by setting bonding pins, so as to achieve signal conduction.

[0106] S232 , bend the flexible circuit board 100 so that the flexible circuit board 100 is attached to the heat dissipation layer 220 , and a portion of the fingerprint module 120 is located in the opening area 221 of the heat dissipation layer 220 .

[0107] In a specific example, the fingerprint module 120 on the flexible circuit board 100 can be aligned with the opening area 221 of the heat dissipation layer 220 first, so that the fingerprint module 120 can be accurately embedded in the opening area 221 of the heat dissipation layer 220 when the flexible circuit board 100 and the heat dissipation layer 220 are bonded together. Then, the flexible circuit board 100 is bent, and the flexible circuit board 100 and the heat dissipation layer 220 are bonded and fixed. The fingerprint module 120 passes through the opening area 221 of the heat dissipation layer 220 and is attached to the display panel 210 by bonding.

[0108] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the embodiments here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A display device, characterized in that: It includes a display panel, a heat dissipation layer on the display panel, and a flexible circuit board; The flexible circuit board includes a circuit board body and a fingerprint module; The circuit board body includes a recessed area corresponding to the fingerprint module, and at least a portion of the fingerprint module is fixed in the recessed area; The fingerprint module is welded to the circuit board body via a transfer circuit board to achieve electrical connection; The recessed area is a through hole that penetrates the circuit board body, and at least one side of the fingerprint module is located outside the through hole; The circuit board body includes a first body portion and a second body portion located at two opposite sides of the recessed area; The flexible circuit board includes a bridge circuit board electrically connecting the first body portion and the second body portion, and the orthographic projection of the bridge circuit board on the circuit board body covers the recessed area; The bridge circuit board is welded to the circuit board body to achieve electrical connection; An opening area corresponding to the recessed area is provided in the heat dissipation layer; The flexible circuit board is attached to a side of the display panel away from the light-emitting side through the heat dissipation layer; Part of the fingerprint module is located in the opening area of ​​the heat dissipation layer.

2. The display device according to claim 1, characterized in that The adapter circuit board is a flexible adapter circuit board.

3. The display device according to claim 1, characterized in that The bridge circuit board is a flexible bridge circuit board.

4. The display device according to claim 1, characterized in that The recessed area is a through hole that penetrates the circuit board body; The circuit board body includes a first body portion and a second body portion located at two opposite sides of the recessed area; The flexible circuit board includes a bridge circuit board electrically connecting the first body portion and the second body portion; The bridge circuit board is welded to the circuit board body to achieve electrical connection; The bridge circuit board is located at a side of the circuit board body away from the display panel.

5. The display device according to claim 1, characterized in that The orthographic projection of the bridge circuit board on the circuit board body covers the recessed area; The fingerprint module is located in a space formed by an opening area of ​​the heat dissipation layer, a recessed area of ​​the circuit board body, the bridge circuit board and the display panel.

6. A method for preparing a display device according to claim 1, characterized in that: include: forming a heat dissipation layer on the display panel; forming an opening area corresponding to the recessed area in the heat dissipation layer; The flexible circuit board is attached to a side of the display panel away from the light-emitting side through the heat dissipation layer, so that part of the fingerprint module is located in the opening area of ​​the heat dissipation layer.

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