Display module, preparation method thereof and display device

Abstract

The invention provides a display module and a preparation method thereof and a display device, the display module comprises a display panel, a backlight module and a chip on film, the display panel comprises a first substrate, a liquid crystal layer and a second substrate, one side, facing the second substrate, of the first substrate is provided with a fanout line in a fanout area, and the fanout line is arranged on the side, facing the second substrate, of the first substrate. The orthographic projection of the second substrate and the liquid crystal layer in the first plane is not overlapped with the orthographic projection of the fan-out area in the first plane; the backlight module is arranged on the side, away from the first substrate, of the second substrate and comprises a first bottom face opposite to the second substrate and a first side face located between the second substrate and the first bottom face, and the included angle between the first side face and the first bottom face is an obtuse angle; the chip on film comprises a first area, a second area and a third area, the first area is arranged on the side, facing the second substrate, of the fan-out line and connected with the fan-out line, the third area is arranged on the side, away from the display panel, of the first bottom face, and the second area is in lap joint contact with the first side face.

Description

Technical Field

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

[0002] At present, the mainstream packaging technologies for display panels include chip on glass (COG), flexible chip on flex (COF) and polyimide chip on pi (COP). These packaging technologies play a key role in reducing the border of display panels. Among them, COP packaging contributes the most to the reduction of the border, followed by COF packaging and finally COG packaging.

[0003] However, in the above packaging method, there are still problems such as light leakage in the bending area and the frame size cannot be further reduced. Summary of the invention

[0004] The purpose of the present disclosure is to provide a display module and a preparation method thereof, and a display device, so as to solve the technical problems in the related art that the bending area of ​​the display module leaks light and the frame size cannot be further reduced.

[0005] In order to achieve the above objectives, the present invention adopts the following technical solutions:

[0006] A first aspect of the present disclosure provides a display module, the display module having a display area and a fan-out area located on one side of the display area, the display module comprising:

[0007] A display panel, the display panel comprising a first substrate, a liquid crystal layer, and a second substrate stacked in sequence, a fan-out line is arranged in the fan-out area on a side of the first substrate facing the second substrate, an orthographic projection of the second substrate and the liquid crystal layer in a first plane does not overlap with an orthographic projection of the fan-out area in the first plane, and the first plane is a plane parallel to the display panel;

[0008] a backlight module, wherein the backlight module is arranged on a side of the second substrate away from the first substrate, the backlight module comprises a first bottom surface arranged opposite to the second substrate and a first side surface located between the second substrate and the first bottom surface, and an angle between the first side surface and the first bottom surface is an obtuse angle;

[0009] A chip-on-cover film, the chip-on-cover film comprising a first region, a second region and a third region, the first region being arranged on a side of the fan-out line facing the second substrate and connected to the fan-out line, the third region being arranged on a side of the first bottom surface away from the display panel, the second region being in overlapping contact with the first side surface, and one end of the second region being connected to an end of the first region close to the display area, and the other end extending to a side of the first bottom surface away from the display panel and connected to the third region.

[0010] Optionally, the display area includes a first edge and a second edge opposite to each other in a first direction, the fan-out area is arranged on a side of the first edge away from the display area, the fan-out area includes a plurality of sub-fan-out areas spaced apart along the second direction, the fan-out line is arranged in the sub-fan-out area on a side of the first substrate facing the second substrate, the display module includes a plurality of chip-on-chip films, one chip-on-chip film corresponds to one sub-fan-out area, and the second direction is perpendicular to the first direction.

[0011] Optionally, the orthographic projection of the first side surface in the first plane overlaps with a first area in the second direction, and the first area is a distribution area of ​​the orthographic projection of the sub-fan-out area on the first plane in the second direction.

[0012] Optionally, the backlight module further includes a second side surface located between the second substrate and the first bottom surface, the second side surface is perpendicular to the first bottom surface, and an orthographic projection of the second side surface in the first plane does not overlap with the first area in the second direction.

[0013] Optionally, the first side surface and the second side surface both include a first end close to the display panel and a second end away from the display panel in a third direction, the first end of the second side surface is flush with a boundary line of the fan-out area away from the display area in the first direction, the distance between the first end of the first side surface and the display area in the first direction is smaller than the distance between the first end of the second side surface and the display area in the first direction, and the third direction is perpendicular to the first direction and the second direction.

[0014] Optionally, the backlight module includes a back panel and a rubber frame, the back panel includes a bottom panel and a first side panel arranged at the edge of the bottom panel, the bottom panel is arranged opposite to the second substrate, the first side panel is arranged between the second substrate and the bottom panel, the angle between the bottom panel and the first side panel is an obtuse angle, the second substrate, the first side panel and the bottom panel form a accommodating space, the rubber frame includes a first rubber frame portion arranged between the first side panel and the second substrate, the first rubber frame portion and the surface of the first side panel away from the accommodating space form the first side surface, and the surface of the bottom panel away from the second substrate forms the first bottom surface.

[0015] Optionally, the back panel also includes a second side panel arranged at the edge of the bottom panel, the second side panel is perpendicular to the bottom panel, the plastic frame also includes a second plastic frame portion arranged on the side of the second side panel away from the accommodating space and a third plastic frame portion arranged between the second side panel and the second substrate, and the surfaces of the second plastic frame portion and the third plastic frame portion away from the accommodating space form the second side surface.

[0016] Optionally, the display module further includes a printed circuit board, which is disposed on a side of the first bottom surface away from the display panel, and the printed circuit board is bound to the third area.

[0017] Optionally, the printed circuit board includes a first printed circuit board, a second printed circuit board and a main control circuit board, the first printed circuit board is bound to the third area of ​​multiple chip-on-chip films on one side of the center line of the second direction, the second printed circuit board is bound to the third area of ​​multiple chip-on-chip films on the other side of the center line of the second direction, and the main control circuit board is connected to the first printed circuit board and the second printed circuit board via a flexible flat cable.

[0018] Optionally, the display module further includes a driving chip, the third region includes a chip area, and the driving chip is integrated in the chip area.

[0019] Optionally, the display module further includes a first polarizer and a second polarizer, wherein the first polarizer is disposed on a side of the first substrate away from the second substrate, and the second polarizer is disposed between the second substrate and the backlight module.

[0020] A second aspect of the present disclosure provides a method for preparing a display module, wherein the display module comprises a display area and a fan-out area located on one side of the display area, and the method for preparing the display module comprises the following steps:

[0021] A display panel is provided, the display panel comprising a first substrate, a liquid crystal layer, and a second substrate stacked in sequence, a fan-out line is arranged in the fan-out area on a side of the first substrate facing the second substrate, an orthographic projection of the second substrate and the liquid crystal layer in a first plane does not overlap with an orthographic projection of the fan-out area in the first plane, and the first plane is a plane parallel to the display panel;

[0022] Assembling the display panel with a backlight module, wherein the backlight module is arranged on a side of the second substrate away from the first substrate, the backlight module comprises a first bottom surface arranged opposite to the second substrate and a first side surface located between the second substrate and the first bottom surface, and an angle between the first side surface and the first bottom surface is an obtuse angle;

[0023] The display panel and the printed circuit board are bound by a chip-on-chip film, the chip-on-chip film includes a first area, a second area and a third area, the first area is arranged on a side of the fan-out line facing the second substrate and connected to the fan-out line, the third area is arranged on a side of the first bottom surface away from the display panel, the second area is in overlapping contact with the first side surface, and one end of the second area is connected to an end of the first area close to the display area, and the other end extends to a side of the first bottom surface away from the display panel and connected to the third area, and the printed circuit board is arranged on a side of the first bottom surface away from the display panel and bound to the third area.

[0024] A third aspect of the present disclosure provides a display device, comprising the display panel as described above.

[0025] The beneficial effects of the present disclosure are as follows:

[0026] The display module of the disclosed embodiment is provided with a fan-out line on the first substrate away from the backlight module, the area where the second substrate is located does not overlap with the area where the fan-out line is located to expose the fan-out line, and the backlight module includes a first bottom surface and a first side surface, the first side surface is arranged at the edge of the first bottom surface and forms an obtuse angle with the first bottom surface, and after the flip chip film is connected to the fan-out line, it can directly extend to the first bottom surface through the first side surface without bending. On the one hand, since the bending area is omitted, the frame size can be reduced, and on the other hand, the risk of light leakage caused by bending can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The specific implementation methods of the present disclosure are further described in detail below with reference to the accompanying drawings.

[0028] Figure 1 It is a schematic diagram for comparing the structures of three packaging technologies in the related art;

[0029] Figure 2 for Figure 1Schematic diagram of the planar structure of the three packaging technologies;

[0030] Figure 3 A schematic diagram of a plane comparison between a display module and a COF packaging structure provided in an embodiment of the present disclosure;

[0031] Figure 4 A schematic diagram showing a structural comparison in the thickness direction between a display module and a COF packaging structure provided in an embodiment of the present disclosure;

[0032] Figure 5 A schematic plan view of a display module and a COF packaging structure provided in an embodiment of the present disclosure;

[0033] Figure 6 A schematic diagram of a planar structure of an embodiment of a display module provided in an embodiment of the present disclosure;

[0034] Figure 7 for Figure 6 A plan view of a backlight module of a display module;

[0035] Figure 8 It is a structural schematic diagram of another embodiment of the display module at the first position P1;

[0036] Fig. 9 A flow chart of a method for preparing a display module provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0038] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one", "one" or "the" do not indicate quantity restrictions, but indicate that there is at least one. Similar words such as "include" or "comprise" mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0039] Please refer to Figure 1 and Figure 2 , Figure 1 It is a schematic diagram of the structural comparison of three packaging technologies in related technologies. Figure 2 for Figure 1 Schematic diagram of the planar structure of the three packaging technologies, such as Figure 1 to Figure 2 As shown, the display module usually includes a color film substrate (CF) and an array substrate (TFT) that are relatively arranged. In the COG packaging technology, the driver chip (Driver IC, referred to as DIC) is directly bound to the glass backplane, that is, the driver chip and the fan-out wiring (Fan-out Wiring) of the display panel are integrated on the glass backplane, and the fan-out wiring is generally concentrated within a 4mm width at the bottom of the lower frame. Since the driver chip and the fan-out wiring occupy a large volume, the lower frame is wider. Compared with the COG packaging technology, the COF packaging technology is improved in that the driver chip is integrated on a flexible film substrate through the flip chip technology. The flexible film substrate with integrated driver chip can also be called flip chip film. Therefore, the driver chip can be directly set to the bottom of the display module, which can save 1.5mm of frame size compared to the COG packaging technology, that is, Figure 1 and Figure 2 The W1 is 1.5mm. COP packaging technology is a packaging technology that binds the driver chip to a polyimide (PI) substrate. It takes advantage of the bendability of the flexible screen and reduces the border to a nearly borderless effect. Figure 1 and Figure 2W2 in the middle represents the reduced width of the border between COP packaging technology and COF packaging technology. Since only the flexible screen of Organic Light-Emitting Diode (OLED) can be bent, while the liquid crystal display (LCD) cannot be bent, the COP packaging technology cannot be applied to the LCD screen, and has the disadvantages of high cost and low yield. In addition, in the above three packaging processes, bending is required to achieve the connection between the printed circuit board (PCB) and the driver chip, and the bending area will occupy a certain border width, which is not conducive to the realization of a narrow border, and the bending area will cause a certain risk of light leakage.

[0040] In order to solve the above technical problems, the present disclosure provides a display module and a manufacturing method thereof, and a display device. Figures 3 to 5 , Figure 3 A schematic diagram of a plane comparison of a display module and a COF packaging structure provided in an embodiment of the present disclosure, Figure 4 A schematic diagram showing a structural comparison of a display module and a COF packaging structure in the thickness direction provided by an embodiment of the present disclosure. Figure 5 FIG. 1 is a cross-sectional schematic diagram of the lower frame of the COF packaging structure in the display module of the embodiment of the present disclosure and the related art in the D-D' direction, as shown in FIG. Figures 3 to 5 As shown, the display module has a display area (Active Area, referred to as AA) and a fan-out area BB located at one side of the display area AA. The display module includes a display panel 10 , a backlight module 20 , a COF 30 and a driving chip 40 .

[0041] Wherein, the display area AA includes a plurality of sub-pixels distributed in an array, and illustratively, the plurality of sub-pixels are distributed in an array along the horizontal direction X and the vertical direction Y. In addition, the display area AA also includes a plurality of gate lines extending along the horizontal direction X and distributed at intervals along the vertical direction Y, and a plurality of data lines extending along the vertical direction Y and distributed at intervals along the horizontal direction X. The gate lines are used to provide row scanning signals for the sub-pixels, and the data lines are used to provide data signals for the sub-pixels. Each sub-pixel is displayed under the control of the row scanning signals and the data signals. Wherein, the signal wiring in the display panel 10, such as the data line, the ground line, the test line, etc., all need to be bound to the driver chip 40, so a fan-out line 110a needs to be set in the fan-out area BB, one end of the fan-out line 110a is connected to the signal wiring in the display panel 10, and the other end is connected to the driver chip 40, so as to realize the signal distribution of the driver chip 40 to each sub-pixel.

[0042] The display module also includes a frame area surrounding the display area AA, for example, the frame area includes a left frame area and a right frame area located on opposite sides of the display area AA in the horizontal direction X, and an upper frame area and a lower frame area located on opposite sides of the display area AA in the vertical direction Y. The fan-out area BB is disposed in one of the frame areas, and the embodiment of the present disclosure is described by taking the fan-out area BB as disposed in the lower frame area as an example.

[0043] Specifically, Figure 4 As shown, the display panel 10 includes a first substrate 110, a liquid crystal layer (not shown) and a second substrate 120 stacked in sequence, a fan-out line 110a is provided in the fan-out area BB on the side of the first substrate 110 facing the second substrate 120, the orthographic projection of the second substrate 120 and the liquid crystal layer in the first plane does not overlap with the orthographic projection of the fan-out area BB in the first plane, and the first plane is a plane parallel to the display panel 10.

[0044] Please refer to Figure 5 , Figure 5 The first position P1 in the figure indicates a position where the chip-on-cover film 30 is disposed, and the second position P2 indicates a position where the chip-on-cover film 30 is not disposed. The view at the first position P1 of the embodiment of the present disclosure indicates Figure 3 The cross-sectional view of the module along the D-D' direction at the position where the flip chip film 30 is provided in the middle, and the view at the second position P2 of the embodiment of the present disclosure represents Figure 3 FIG. 5 is a cross-sectional view of the module along the DD′ direction at a position where the chip-on-film 30 is not provided.

[0045] like Figure 5 As shown, the backlight module 20 is arranged on the side of the second substrate 120 away from the first substrate 110, and the backlight module 20 includes a first bottom surface 20a arranged opposite to the second substrate 120 and a first side surface 20b located between the second substrate 120 and the first bottom surface 20a, and the angle α between the first side surface 20b and the first bottom surface 20a is an obtuse angle.

[0046] The flip chip film 30 includes a first area 310, a second area 320 and a third area 330. The first area 310 is arranged on the side of the fan-out line 110a facing the second substrate 120 and is connected to the fan-out line 110a. The third area 330 is arranged on the side of the first bottom surface 20a away from the display panel 10. The second area 320 overlaps and contacts the first side surface 20b, and one end of the second area 320 is connected to an end of the first area 310 close to the display area AA, and the other end extends to the side of the first bottom surface 20a away from the display panel 10 and is connected to the third area 330.

[0047] Among them, the flip chip film 30 includes structures such as a flexible film substrate, an integrated circuit chip, a metal wire and a protective layer. The flexible film substrate is usually made of flexible materials such as polyimide (PI) and has good heat resistance and mechanical strength; the integrated circuit chip is directly installed on the flexible film substrate through flip chip technology (Flip Chip) to achieve high-density connection; the metal wires (usually copper) on the flexible film substrate are used to transmit signals and data; the protective layer covers the metal wires and the integrated circuit chip to prevent the external environment from damaging the circuit.

[0048] In the disclosed embodiment, the third area 330 also includes a chip area, and the driver chip 40 is integrated in the chip area, that is, the integrated circuit chip on the chip-on-chip film 30 is the driver chip 40, and the driver chip 40 is arranged in the third area 330 of the chip-on-chip film 30, that is, the driver chip 40 is located on the side of the backlight module 20 away from the display panel 10, so that the size of the lower frame of the display module can be reduced.

[0049] The COF packaging in each of the drawings of the embodiments of the present disclosure refers to the packaging structure in the related art. Compared with the COF packaging structure in the related art, the display module of the embodiments of the present disclosure has the following major improvements:

[0050] (1) The first substrate 110 is an array substrate, the second substrate 120 is a color filter substrate, and the second substrate 120 is slightly smaller than the first substrate 110 in the fan-out area BB. Specifically, at the position of the lower frame, the boundary line of the second substrate 120 is inwardly retracted relative to the boundary line of the first substrate 110 to expose the fan-out line 110a on the first substrate 110, that is, the orthographic projection of the second substrate 120 in the first plane does not overlap with the orthographic projection of the fan-out line 110a in the first plane, so that the COF 30 can be directly connected to the fan-out line 110a on the first substrate 110. In addition, the liquid crystal layer is usually distributed only in the display area AA, so the liquid crystal layer in the fan-out area BB will not block the fan-out line 110a.

[0051] (2) The backlight module 20 is provided with an escape space at the position of the fan-out line 110a, so that after the chip-on-chip film 30 is connected to the fan-out line 110a, it can directly extend to the escape space through the retracted side surface of the second substrate 120, and extend to the back side of the backlight module 20 (that is, the side away from the display panel 10) in the escape space, and then connect with the printed circuit board arranged on the back side of the backlight module 20. At this time, the chip-on-chip film 30 does not need to be bent, and the space occupied by the bending area can be omitted, thereby reducing the frame size of the display module; at the same time, since the bending area is eliminated, the chip-on-chip film 30 does not need to be bent, so the width of the fan-out line 110a (that is, the length in the vertical direction Y) can also be appropriately reduced, further reducing the frame size of the display module.

[0052] Optionally, the avoidance space may be a recessed portion provided on the backlight module 20. For example, Figure 5 As shown, in the disclosed embodiment, the backlight module 20 includes a first bottom surface 20a disposed opposite to the second substrate 120 and a first side surface 20b disposed between the second substrate 120 and the first bottom surface 20a, and the first side surface 20b is an inclined surface. Specifically, the angle α between the first side surface 20b and the first bottom surface 20a is an obtuse angle, and at this time, the first side surface 20b and the extension line of the first bottom surface 20a form an acute angle, and the space formed between the first side surface 20b and the extension line of the first bottom surface 20a can be understood as the recessed portion of the backlight module 20, that is, the avoidance space as described above.

[0053] Among them, the angle α between the first side surface 20b and the first bottom surface 20a is designed to be an obtuse angle, which can provide a smooth slope with a height gradient. The height gradient here is mainly manifested as follows: in the first direction Y, the closer to the display area AA, the smaller the vertical distance between the first side surface 20b and the first bottom surface 20a, and the farther away from the display area AA, the smaller the vertical distance between the first side surface 20b and the first bottom surface 20a. In the process of binding the chip-on-cover film 30 to the printed circuit board on the back of the backlight module 20, the chip-on-cover film 30 can smoothly extend from the position of the fan-out line 110a along the slope (that is, the first side surface 20b) to the back of the backlight module 20. On the contrary, if the first side surface 20b is too steep or uneven, the chip-on-cover film 30 may not be able to fit smoothly, which may easily cause poor connection and affect the connection reliability.

[0054] It can be understood that the backlight module in the embodiment of the present disclosure utilizes the angle between the first side surface 20b and the second surface 20a to form an escape space for the flip chip film 30 to pass through, and in specific implementation, various shapes or patterns of hollows or grooves can be set on the backlight module 20 to form the above-mentioned escape space, and the embodiment of the present disclosure does not limit it.

[0055] (3) The chip-on-cover film 30 includes a first region 310, a second region 320 and a third region 330 which are connected in sequence, wherein the first region 310 and the third region 330 are parallel to the first plane, the second region 320 is parallel to the first side surface 20a, the first region 310 is arranged at the position of the fan-out line 110a and is connected to the fan-out line 110a, the second region 320 is laid flat on the first side surface 20b, and one end of the second region 320 is connected to the first region 310. Specifically, the second region 320 is connected to one end of the first region 310 close to the display area AA, and the other end of the second region 320 extends to the back side of the backlight module 20 and is connected to the third region 330. In this way, the chip-on-cover film 30 can be directly extended to the back side of the backlight module 20 without being bent. It can be understood that the flip chip film 30 in the embodiment of the present disclosure includes the first area 310, the second area 320 and the third area 330. This is a division for the convenience of description. In a specific implementation, the flip chip film 30 can also be an integrated structure, that is, the first area 310, the second area 320 and the third area 330 are integrally formed.

[0056] Compared with the related art, the display module of the embodiment of the present disclosure is provided with a fan-out line on the first substrate away from the backlight module, the area where the second substrate is located does not overlap with the area where the fan-out line is located to expose the fan-out line, and the backlight module includes a first bottom surface and a first side surface, the first side surface is arranged at the edge of the first bottom surface and forms an obtuse angle with the first bottom surface, and after the flip chip film is connected to the fan-out line, it can directly extend to the first bottom surface through the first side surface without bending. On the one hand, since the bending area is omitted, the frame size can be reduced, and on the other hand, the risk of light leakage caused by bending can be avoided.

[0057] In one possible implementation, Figure 6 to Figure 7 As shown, Figure 6 is a schematic diagram of a planar structure of an embodiment of a display module, Figure 7 for Figure 6 A planar schematic diagram of a backlight module, wherein the display area AA includes a first edge and a second edge opposite to each other in a first direction, the fan-out area BB is arranged on a side of the first edge away from the display area AA, the fan-out area BB includes a plurality of sub-fan-out areas spaced apart along a second direction, the fan-out line is arranged in the sub-fan-out area on the side of the first substrate 110 facing the second substrate 120, the display module includes a plurality of the chip-on-chip films 30, one chip-on-chip film 30 corresponds to one sub-fan-out area, and the second direction is perpendicular to the first direction.

[0058] Optionally, the first direction is the vertical direction Y, and the second direction is the horizontal direction X. When the display panel is large in the horizontal direction X, multiple signal lines can be fanned out in different areas. In this case, the fan-out area BB includes multiple sub-fan-out areas spaced apart along the second direction X, and each sub-fan-out area is provided with a fan-out line. Correspondingly, the display module needs to include multiple chip-on-chip films 30, each of which is used to realize the connection between the fan-out line in its corresponding sub-fan-out area and the driver chip.

[0059] When the display module includes a plurality of COFs 30 , the display module includes a plurality of driver chips 40 , and the third region 330 of each COF 30 includes a chip region, and one or more driver chips 40 are disposed in the chip region.

[0060] In a possible implementation, the display module further includes a printed circuit board 50 , which is disposed on a side of the first bottom surface 20 a away from the display panel 10 , and the printed circuit board 50 is bound to the third area 330 .

[0061] Optional, such as Figure 6 As shown, the printed circuit board 50 includes a first printed circuit board 510, a second printed circuit board 520 and a main control circuit board 530. The first printed circuit board 510 is bound to the third area 330 of multiple flip chip films 30 on one side of the second direction center line L1, and the second printed circuit board 520 is bound to the third area 330 of multiple flip chip films 30 on the other side of the second direction center line L1. The main control circuit board 530 is connected to the first printed circuit board 510 and the second printed circuit board 520 via a flexible flat cable (Flexible Flat Cable, FFC for short).

[0062] The second direction center line L1 represents the center line in the second direction X, that is, the display module is divided into two areas in the second direction X by the second direction center line L1, and the control signals are provided to the sub-pixels in the two areas respectively by the first printed circuit board 510 and the second printed circuit board 520. The first printed circuit board 510 or the second printed circuit board 520 is bound to the third area 330 of the COF 30, which can also be understood as the first printed circuit board 510 or the second printed circuit board 520 is connected to the driving chip 40 in the third area 330.

[0063] Among them, the first printed circuit board 510 can also be expressed as PCB-L, the second printed circuit board 520 can also be expressed as PCB-R, and the main control circuit board 530 can also be expressed as a timing control board (Timing Controller), that is, a TCON board. The first printed circuit board 510 is used to connect to the driver chip 40 corresponding to the sub-pixels in the left half of the display area, and the second printed circuit board 520 is used to connect to the driver chip 40 corresponding to the sub-pixels in the right half of the display area. The main control circuit board 530 is used to convert the image signal Vin from the graphics card or processor into a timing signal that can be recognized by the display module, thereby controlling the brightness and color of each sub-pixel.

[0064] For example, Figure 6 As shown, the fan-out area BB includes 12 sub-fan-out areas, and 12 flip chip films 30 are provided correspondingly. Figure 6 The CF&BLU side specifically refers to the schematic diagram of the second substrate 120 and the backlight module 20 side. Figure 6 It can be seen that in the COF packaging structure of the related art, the chip-on-chip film is bent from one side of the array substrate to the backlight side, while in the display module of the embodiment of the present disclosure, the driver chip 40 and the printed circuit board 50 are arranged on the back side of the backlight module 20, and the backlight module 20 is provided with an avoidance space, and the chip-on-chip film 30 is directly extended from the first substrate 110 to the back side of the backlight module 20 through the avoidance space without bending.

[0065] Optionally, the orthographic projection of the first side surface 20b in the first plane overlaps with the first area in the second direction X, and the first area is a distribution area in the second direction X of the orthographic projection of the sub-fan-out area on the first plane.

[0066] When the display module includes multiple chip-on-chip films 30, in the embodiment of the present disclosure, the backlight module 20 is also designed in a segmented manner along the second direction X at the position of the lower frame. Specifically, the side of the backlight module 20 in the area where the chip-on-chip film 30 is provided (that is, the area where the sub-fan-out area is located) is a first side 20b, and the area where the chip-on-chip film 30 is located can also be represented by the distribution area of ​​the sub-fan-out area on the first plane in the second direction.

[0067] Optional, such as Figure 5 As shown, the backlight module 20 also includes a second side surface 20c located between the second substrate 120 and the first bottom surface 20a, the second side surface 20c is perpendicular to the first bottom surface 20a, and the orthographic projection of the second side surface 20a in the first plane does not overlap with the first area in the second direction Y.

[0068] In the embodiment of the present disclosure, in the second direction X, the backlight module 20 adopts a segmented design, specifically, the area where the chip-on-chip film 30 is provided (that is, the area where the sub-fan-out area is located) is the first side 20b, and the area where the chip-on-chip film 30 is not provided (that is, the area outside the chip-on-chip film 30 in the second direction X) is the second side 20c. In the area where the chip-on-chip film 30 is not provided, since there is no need to provide an escape space for the chip-on-chip film 30, the backlight module 20 can adopt a conventional design in this area, that is, the second side 20c is perpendicular to the first bottom surface 20a, and the backlight module 20 has a better supporting effect.

[0069] For example, Figure 7 As shown, Figure 7 Where P1 indicates a position where the chip-on-chip film 30 is disposed, and P2 indicates a position where the chip-on-chip film 30 is not disposed. Figure 7 It can be seen that at the location where the chip-on-film 30 is disposed, the backlight module 20 forms an inwardly contracted avoidance space for the chip-on-film 30 to pass through, and at the location where the chip-on-film 30 is not disposed, the backlight module 20 adopts a conventional design.

[0070] Optional, such as Figure 5 In other words, the first side surface 20b and the second side surface 20c each include a first end close to the display panel 10 and a second end away from the display panel 10 in a third direction, the first end of the second side surface 20c is flush with a boundary line of the fan-out area BB away from the display area AA in the first direction Y, the distance between the first end of the first side surface 20b and the display area in the first direction Y is smaller than the distance between the first end of the second side surface 20c and the display area AA in the first direction Y, and the third direction is perpendicular to the first direction Y and the second direction X. The third direction is the thickness direction Z of the display module.

[0071] Specifically, the two ends of the first side surface 20b and the second side surface 20c in the third direction Z are respectively represented as the first end and the second end, wherein the first end of the first side surface 20b is retracted compared to the first end of the second side surface 20c, and the retraction here means being closer to the display area AA, that is, the distance from the display area AA in the first direction Y is smaller, and the first end of the second side surface 20c can also be understood as the boundary line of the lower frame area away from the display area AA.

[0072] Compared with the display module in the related art, the embodiment of the present disclosure eliminates the bending area in the lower frame, so the size of the lower frame area can be reduced. At this time, the boundary line of the lower frame can be moved inward as a whole (that is, moved in the second direction Y toward the display area AA).

[0073] The boundary line of the lower frame can also be understood as the position of the orthographic projection of the first end of the second side surface 20c in the backlight module 20 in the first plane. Therefore, when the size of the lower frame is reduced, the second side surface 20c is moved inward compared with the prior art. Figure 5 As shown, the inward displacement distance is represented as d1.

[0074] In one possible implementation, Figure 5 As shown, the backlight module 20 includes a back cover (BC) 210 and a model frame (MF) 220, the back cover 210 includes a bottom plate 2110 and a first side plate 2120 arranged at the edge of the bottom plate 2110, the bottom plate 2110 is arranged opposite to the second substrate 120, the first side plate 2120 is arranged between the second substrate 120 and the bottom plate 2110, the angle between the bottom plate 2110 and the first side plate 2120 is an obtuse angle, the second substrate 120, the first side plate 2120 and the bottom plate 2110 form a accommodating space, the model frame 220 includes a first frame portion 2210 arranged between the first side plate 2120 and the second substrate 120, the surfaces of the first frame portion 2210 and the first side plate 2120 away from the accommodating space form the first side surface 20b, and the surface of the bottom plate 2110 away from the second substrate 120 forms the first bottom surface 20a.

[0075] In the disclosed embodiment, in the area where the COF film 30 is provided, the back panel 210 in the backlight module 20 includes a first side panel 2120, and the first side panel 2120 is inclined with the bottom panel 2110, specifically, the angle between the first side panel 2120 and the bottom panel 2110 is an obtuse angle. At the same time, the plastic frame 220 includes a first plastic frame portion 2210 provided between the second substrate 120 and the first side panel 2120 in the third direction Z, and the outer surface of the first plastic frame portion 2210, that is, the side surface away from the display area AA, is also inclined, and the angle between it and the bottom panel 2110 is also an obtuse angle. The first side panel 2120 and the side surface of the first plastic frame portion 2210 away from the display area AA (that is, the surface away from the accommodating space) together form the above-mentioned first side surface 20b.

[0076] It is understandable that the backlight module in the embodiment of the present disclosure uses the obtuse angle between the first side plate 2120 and the bottom plate 2110 to form an escape space for the chip-on-chip film 30 to pass through, and in specific implementation, various shapes or patterns of hollowing or digging grooves can be set on the backlight module 20 to form the above-mentioned escape space. For example, please refer to Figure 8 , Figure 8 It is a structural schematic diagram of another embodiment of the display module at the first position P1. Figure 8In the illustrated embodiment, the back plate 210 further includes a second bottom plate 2140 parallel to the bottom plate 2110 , the distance between the second bottom plate 2140 and the display panel 10 is greater than the distance between the bottom plate 2110 and the display panel 10 , and the angle between the first side plate 2120 and the second bottom plate 214 is an obtuse angle.

[0077] Optionally, the back plate 210 further includes a second side plate 2130 disposed at the edge of the bottom plate 2110, the second side plate 2130 is perpendicular to the bottom plate 2110, the plastic frame 220 further includes a second plastic frame portion 2220 disposed on the side of the second side plate 2130 away from the accommodating space and a third plastic frame portion 2230 disposed between the second side plate 2130 and the second substrate 120, and the surfaces of the second plastic frame portion 2220 and the third plastic frame portion 2230 away from the accommodating space form the second side surface 20c. At this time, the bottom plate 2110, the first side plate 2120, the second side plate 2130 and the second substrate 120 together enclose a accommodating space.

[0078] In the disclosed embodiment, in the area where the chip-on-cover film 30 is not provided, the back panel 210 in the backlight module 20 includes a second side panel 2120, and the second side panel 2120 is at a right angle to the bottom panel 2110, that is, in a vertical state. At this time, the second frame portion 2220 and the third frame portion 2230 are away from the surface of the accommodating space to form the second side surface 20c.

[0079] Optional, such as Figure 5 As shown, in addition to the back plate 210 and the plastic frame 220, the backlight module 20 may also include structures such as an optical film material 230, a reflective sheet 240, and a light guide plate (LGP) 250 disposed in the above-mentioned accommodation space. Among them, the reflective sheet 240, the light guide plate 250 and the optical film layer 230 are stacked in sequence in a direction away from the bottom plate 2110. In addition, the backlight module 20 may also include foam disposed between the first plastic frame portion 2210 and the second substrate 120, and between the third plastic frame portion 2230 and the second substrate 120.

[0080] In a possible implementation, the display module further includes a first polarizer and a second polarizer, wherein the first polarizer is disposed on a side of the first substrate 110 away from the second substrate 120, and the second polarizer is disposed between the second substrate 120 and the backlight module 20. It is understandable that in order to realize that the COF 30 extends directly from the position of the fan-out line 110 to the back of the backlight module 20, the size of the second polarizer may be the same as or slightly smaller than the size of the second substrate 120. In a specific implementation, the orthographic projection of the second substrate 120 in the first plane needs to cover the orthographic projection of the second polarizer in the first plane.

[0081] Based on the same inventive concept, the second aspect of the present disclosure provides a method for preparing a display module, wherein the display module has a display area and a fan-out area located on one side of the display area, such as Fig. 9 As shown, the method for preparing the display module comprises the following steps:

[0082] Step S101, providing a display panel, the display panel comprising a first substrate, a liquid crystal layer, and a second substrate stacked in sequence, a fan-out line is arranged in the fan-out area on a side of the first substrate facing the second substrate, an orthographic projection of the second substrate and the liquid crystal layer in a first plane does not overlap with an orthographic projection of the fan-out area in the first plane, and the first plane is a plane parallel to the display panel;

[0083] Step S102, assembling the display panel and the backlight module, wherein the backlight module is arranged on a side of the second substrate away from the first substrate, the backlight module comprises a first bottom surface arranged opposite to the second substrate and a first side surface located between the second substrate and the first bottom surface, and an angle between the first side surface and the first bottom surface is an obtuse angle;

[0084] Step S103, using a chip-on-chip film to bind the display panel and the printed circuit board, the chip-on-chip film includes a first area, a second area and a third area, the first area is arranged on a side of the fan-out line facing the second substrate and connected to the fan-out line, the third area is arranged on a side of the first bottom surface away from the display panel, the second area is in overlapping contact with the first side surface, and one end of the second area is connected to an end of the first area close to the display area, and the other end extends to a side of the first bottom surface away from the display panel and connected to the third area, and the printed circuit board is arranged on a side of the first bottom surface away from the display panel and bound to the third area.

[0085] Optionally, when the display module further includes a first polarizer and a second polarizer, the first polarizer is disposed on a side of the first substrate away from the second substrate, and the second polarizer is disposed between the second substrate and the backlight module.

[0086] In the related art, when the COF packaging structure is adopted, the packaging process is as follows: firstly, a polarizer is attached to the display panel, then an OLB (COF & PCB Bonding) process is performed, that is, the display panel and the printed circuit board are bound by a flip chip film, and finally an Ass'y process is performed, that is, the backlight module is assembled.

[0087] As for the display module of the embodiment of the present disclosure, since an avoidance space for the flip chip film to pass through is formed on the backlight module, its packaging process can be: firstly, the first polarizer and the second polarizer are attached to the display panel, and then the Ass'y process is performed, that is, the display panel and the backlight module are assembled, and finally the OLB process is performed, that is, the flip chip film is used to bind the display panel and the printed circuit board.

[0088] Based on the same inventive concept, the third aspect of the present disclosure provides a display device, including the display panel as described above. Exemplarily, the display device can be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a monitor, a notebook computer, a digital photo frame, a navigator, etc., which is not limited in this embodiment.

[0089] Obviously, the above embodiments of the present disclosure are merely examples for clearly illustrating the present disclosure, and are not limitations on the implementation methods of the present disclosure. For ordinary technicians in this field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present disclosure are still within the protection scope of the present disclosure.

Claims

1. A display module, characterized in that: The display module has a display area and a fan-out area located on one side of the display area, and the display module includes: A display panel, the display panel comprising a first substrate, a liquid crystal layer, and a second substrate stacked in sequence, a fan-out line is arranged in the fan-out area on a side of the first substrate facing the second substrate, an orthographic projection of the second substrate and the liquid crystal layer in a first plane does not overlap with an orthographic projection of the fan-out area in the first plane, and the first plane is a plane parallel to the display panel; a backlight module, wherein the backlight module is arranged on a side of the second substrate away from the first substrate, the backlight module comprises a first bottom surface arranged opposite to the second substrate and a first side surface located between the second substrate and the first bottom surface, and an angle between the first side surface and the first bottom surface is an obtuse angle; A chip-on-cover film, the chip-on-cover film comprising a first region, a second region and a third region, the first region being arranged on a side of the fan-out line facing the second substrate and connected to the fan-out line, the third region being arranged on a side of the first bottom surface away from the display panel, the second region being in overlapping contact with the first side surface, and one end of the second region being connected to an end of the first region close to the display area, and the other end extending to a side of the first bottom surface away from the display panel and connected to the third region.

2. The display module according to claim 1, characterized in that: The display area includes a first edge and a second edge opposite to each other in a first direction, the fan-out area is arranged on a side of the first edge away from the display area, the fan-out area includes a plurality of sub-fan-out areas spaced apart along a second direction, the fan-out line is arranged in the sub-fan-out area on a side of the first substrate facing the second substrate, the display module includes a plurality of chip-on-chip films, one chip-on-chip film corresponds to one sub-fan-out area, and the second direction is perpendicular to the first direction.

3. The display module according to claim 2, characterized in that: The orthographic projection of the first side surface in the first plane overlaps with the first area in the second direction, and the first area is a distribution area of ​​the orthographic projection of the sub-fan-out area on the first plane in the second direction.

4. The display module according to claim 3, characterized in that: The backlight module further includes a second side surface located between the second substrate and the first bottom surface, the second side surface is perpendicular to the first bottom surface, and an orthographic projection of the second side surface in the first plane does not overlap with the first area in the second direction.

5. The display module according to claim 4, characterized in that: The first side surface and the second side surface each include a first end close to the display panel and a second end away from the display panel in a third direction, the first end of the second side surface is flush with a boundary line of the fan-out area away from the display area in the first direction, the first end of the first side surface is at a distance from the display area in the first direction that is smaller than the distance from the first end of the second side surface to the display area in the first direction, and the third direction is perpendicular to the first direction and the second direction.

6. The display module according to claim 4, characterized in that: The backlight module includes a back plate and a plastic frame, the back plate includes a bottom plate and a first side plate arranged at the edge of the bottom plate, the bottom plate is arranged opposite to the second substrate, the first side plate is arranged between the second substrate and the bottom plate, the angle between the bottom plate and the first side plate is an obtuse angle, the second substrate, the first side plate and the bottom plate form a accommodating space, the plastic frame includes a first plastic frame portion arranged between the first side plate and the second substrate, the first plastic frame portion and the surface of the first side plate away from the accommodating space form the first side surface, and the surface of the bottom plate away from the second substrate forms the first bottom surface.

7. The display module according to claim 6, characterized in that: The back plate also includes a second side plate arranged at the edge of the bottom plate, the second side plate is perpendicular to the bottom plate, the plastic frame also includes a second plastic frame portion arranged on the side of the second side plate away from the accommodating space and a third plastic frame portion arranged between the second side plate and the second substrate, and the surfaces of the second plastic frame portion and the third plastic frame portion away from the accommodating space form the second side surface.

8. The display module according to claim 2, characterized in that: The display module further includes a printed circuit board, which is disposed on a side of the first bottom surface away from the display panel, and is bound to the third area.

9. The display module according to claim 8, characterized in that: The printed circuit board includes a first printed circuit board, a second printed circuit board and a main control circuit board. The first printed circuit board is bound to the third area of ​​multiple flip chip films on one side of the center line of the second direction, and the second printed circuit board is bound to the third area of ​​multiple flip chip films on the other side of the center line of the second direction. The main control circuit board is connected to the first printed circuit board and the second printed circuit board through a flexible flat cable.

10. The display module according to claim 1, characterized in that: The display module further includes a driving chip, the third region includes a chip area, and the driving chip is integrated in the chip area.

11. The display module according to claim 1, characterized in that: The display module further includes a first polarizer and a second polarizer. The first polarizer is disposed on a side of the first substrate away from the second substrate, and the second polarizer is disposed between the second substrate and the backlight module.

12. A method for preparing a display module, characterized in that: The display module comprises a display area and a fan-out area located on one side of the display area. The method for preparing the display module comprises the following steps: A display panel is provided, the display panel comprising a first substrate, a liquid crystal layer, and a second substrate stacked in sequence, a fan-out line is arranged in the fan-out area on a side of the first substrate facing the second substrate, an orthographic projection of the second substrate and the liquid crystal layer in a first plane does not overlap with an orthographic projection of the fan-out area in the first plane, and the first plane is a plane parallel to the display panel; Assembling the display panel with a backlight module, wherein the backlight module is arranged on a side of the second substrate away from the first substrate, the backlight module comprises a first bottom surface arranged opposite to the second substrate and a first side surface located between the second substrate and the first bottom surface, and an angle between the first side surface and the first bottom surface is an obtuse angle; The display panel and the printed circuit board are bound by a chip-on-chip film, the chip-on-chip film includes a first area, a second area and a third area, the first area is arranged on a side of the fan-out line facing the second substrate and connected to the fan-out line, the third area is arranged on a side of the first bottom surface away from the display panel, the second area is in overlapping contact with the first side surface, and one end of the second area is connected to an end of the first area close to the display area, and the other end extends to a side of the first bottom surface away from the display panel and connected to the third area, and the printed circuit board is arranged on a side of the first bottom surface away from the display panel and bound to the third area.

13. A display device, characterized in that: Comprising a display module as described in any one of claims 1 to 11.

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