Display module, preparation method thereof and spliced display screen

Abstract

The application provides a display module, comprising a backlight module and a display panel, the display panel comprising a display side and a back side, the display side and the back side being opposite; the backlight module comprising a middle frame, the middle frame being located at the back side of the display panel and surrounding the four peripheral edges of the display panel to form support for the four peripheral edges of the display panel; the display module further comprising a flexible binding circuit board, the binding circuit board being connected to at least one side edge of the display side of the display panel; the flexible binding circuit board being bent from the display side of the display panel to the outside of the corresponding side middle frame; the support surface of the middle frame and the display panel being bonded by adhesive; the orthographic projection of the adhesive on the display panel being located in the overlapping area of the orthographic projection of the support surface and the display panel. The display module can avoid metal migration in the metal wires, thereby avoiding short circuit between adjacent metal wires in the flexible binding circuit board and ensuring the display quality of the display module.

Description

Technical Field

[0001] This invention belongs to the field of display technology, specifically relating to a display module, its manufacturing method, and a splicing display screen. Background Technology

[0002] With social development, the application scenarios of video wall displays have become more diverse. However, the high temperature and humidity environment has always been a source of concern for the use of video wall displays. Rainy seasons, coastal cities, and southern cities are all high temperature and humidity application scenarios.

[0003] High temperature and high humidity environments can easily cause products to age faster. Copper migration can occur between adjacent copper conductors (COFLead) inside the flexible bonding circuit board, which can lead to short circuits, poor wiring, and ultimately render the entire product unusable. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a display module, including a backlight module and a display panel, wherein the display panel includes a display side and a back side, and the display side and the back side are opposite to each other;

[0005] The backlight module includes a middle frame, which is located on the back side of the display panel and surrounds the four edges of the display panel to provide support for the four edges of the display panel.

[0006] The display module further includes a flexible bonding circuit board, which is bonded to at least one edge of the display side of the display panel; the flexible bonding circuit board is bent from the display side of the display panel to the outside of the corresponding side of the middle frame;

[0007] The supporting surface of the middle frame is bonded to the display panel with adhesive.

[0008] The orthographic projection of the adhesive on the display panel is located in the area where the orthographic projections of the support surface and the display panel overlap.

[0009] Optionally, a fluorinated layer is provided on the side of the flexible bonding circuit board facing the middle frame;

[0010] The fluorinated layer at least covers the side of the flexible bonded circuit board facing the middle frame at the bend root;

[0011] The bending root is the portion of the flexible bonding circuit board from the bending point to the position flush with the adhesive.

[0012] Optionally, the orthographic projection of the supporting surface onto the display panel is located on the display panel.

[0013] Optionally, the outer edge of the orthographic projection of the support surface onto the display panel coincides with the corresponding side edge of the display panel.

[0014] Optionally, the width of the middle frame support surface ranges from 0.8 to 1.1 mm;

[0015] The width of the support surface is the dimension of the support surface along the edge of the display panel toward the center area of ​​the display panel.

[0016] Optionally, the backlight module further includes a back plate located on the side of the mid-frame opposite to the display panel;

[0017] The cross-sectional shape of the middle frame perpendicular to the display panel is an inverted U-shape;

[0018] The back panel includes a bottom wall and a side wall, the side wall surrounds the bottom wall and the side wall is connected to the bottom wall to form an L-shaped shape;

[0019] The inverted U-shaped opening of the middle frame faces the back plate, and the side wall is partially embedded in the inverted U-shaped opening of the middle frame. The side wall and the outer side wall of the inverted U-shaped middle frame are fixedly connected by a first connector.

[0020] The display module also includes a peripheral circuit board, which is fixed to the outer side surface of the sidewall;

[0021] The flexible bonding circuit board extends to connect with the peripheral circuit board.

[0022] Optionally, it also includes a protective cover plate disposed on the side of the peripheral circuit board away from the sidewall, the upper end of the protective cover plate extending to be flush with the display side surface of the display panel;

[0023] The middle portion of the protective cover plate correspondingly shields the outer circuit board;

[0024] The lower end of the protective cover plate forms an L-shaped bend with a bending angle greater than 90° and less than 180°. The lower end of the bend plate away from the middle part of the protective cover plate is fixedly connected to the corresponding side wall by a second connector.

[0025] Optionally, the upper end of the protective cover is formed with a plurality of rectangular tooth-like structures spaced apart.

[0026] The flexible bonding circuit board is exposed in the spaced area between the rectangular toothed structures;

[0027] The rectangular toothed structure is bent at 1.5° to 2° relative to the middle part of the protective cover towards the edge face of the display panel.

[0028] Optionally, it also includes multiple LEDs arranged in an array on the bottom wall of the back plate;

[0029] The bottom wall includes a first zone, a second zone, and a third zone, with the second zone and the first zone sequentially surrounding the periphery of the third zone;

[0030] The spacing between adjacent LED beads in the first zone is smaller than the spacing between adjacent LED beads in the second zone;

[0031] The spacing between adjacent LED beads in the second zone is greater than the spacing between adjacent LED beads in the third zone;

[0032] The spacing between adjacent LED beads in the first zone is smaller than the spacing between adjacent LED beads in the third zone.

[0033] Optionally, the backlight module further includes a light guide strip, a diffuser plate, and a diffuser sheet;

[0034] The light guide strip, the diffuser plate, and the diffuser sheet are located within the space formed by the back plate and the middle frame, and are stacked sequentially away from the LED beads;

[0035] The light guide strips are distributed around the four edges of the display panel;

[0036] The middle frame includes a boss located between the support surface and the inverted U-shaped opening;

[0037] The light guide strip is located on the protrusion and is fixedly connected to the protrusion;

[0038] The diffuser includes at least two sub-diffusers, which are stacked sequentially on the side of the diffuser plate away from the lamp bead.

[0039] The diffuser plate is spaced apart from the lamp beads.

[0040] Optionally, it may also include a first fastening tape and a second fastening tape;

[0041] The second fastening tape is attached to the side of the protective cover away from the side wall, and the upper edge of the second fastening tape is flush with the display side surface of the display panel.

[0042] The first fastening tape is attached to the side of the second fastening tape opposite to the protective cover, and the first fastening tape also extends to cover the display side frame of the display panel.

[0043] The first fastening tape is also attached to the outer side of the middle frame on the non-bonding side of the display panel, and the upper edge of the first fastening tape on this side is flush with the display side surface of the display panel.

[0044] This invention also provides a splicing display screen, including at least two of the above-mentioned display modules, wherein the at least two display modules are spliced ​​together;

[0045] The display module includes a bonded side edge and an unbonded side edge, and the flexible bonded circuit board in the display module is disposed on the bonded side edge;

[0046] The bound side edge of the display module is spliced ​​with the unbound side edge.

[0047] Optionally, the seam width of the display panel in the display module ranges from 1.2 to 2.0 mm.

[0048] Optionally, the seam width of the display module ranges from 1.8 to 2.6 mm.

[0049] This invention also provides a method for manufacturing the above-mentioned display module, comprising:

[0050] The backlight module and display panel are fabricated separately.

[0051] Apply adhesive to the support surface of the middle frame in the backlight module;

[0052] The display panel is placed on the support surface to achieve bonding between the backlight module and the display panel;

[0053] The adhesive is applied by spraying through a spray valve, and the temperature range of the spray valve during spraying is 100℃~120℃;

[0054] The frequency range of the valve striker is 900–1000 Hz;

[0055] The adhesive application speed range for the bonding edge of the display module is 140–150 mm / s;

[0056] The adhesive application speed range for the non-bonded edge of the display module is 90–100 mm / s;

[0057] Before the display panel is bonded to the backlight module, the initial curing energy range of the adhesive is 1000–1100 mJ / cm². 2 ;

[0058] After the display panel is bonded to the backlight module, the pressure holding weight of the adhesive is 0 kg.

[0059] The beneficial effects of the present invention are as follows: The display module provided by the present invention ensures that the orthographic projection of the adhesive on the display panel is located in the overlapping area of ​​the orthographic projection of the support surface and the display panel. This prevents the display module from having excess adhesive around the bonding surface between the support surface of the middle frame and the display panel after the display panel and the backlight module are bonded together. This avoids the flexible bonding circuit board bent to the outside of the middle frame from contacting the excess adhesive and forming a sealed space. Consequently, it prevents moisture and sulfur foreign matter in the air from entering the sealed space and invading the flexible bonding circuit board. This, in turn, prevents moisture and sulfur foreign matter from forming a galvanic cell reaction with the electrically conductive metal wires (such as copper wires) in the flexible bonding circuit board, preventing metal migration in the metal wires. Ultimately, it prevents short circuits between adjacent metal wires in the flexible bonding circuit board, ensuring the display quality of the display module.

[0060] The splicing display screen provided by the present invention, by adopting the display module in the above embodiments, can not only achieve an extremely narrow bezel in the splicing display screen, but also avoid short circuits between adjacent metal wires in the flexible bonding circuit board, thus ensuring the display quality of the splicing display screen. Attached Figure Description

[0061] Figure 1 This is a schematic diagram of a partial edge structure of a display module in related technologies;

[0062] Figure 2 This is a schematic diagram illustrating the principle of copper migration in copper conductors of flexible bonded circuit boards in related technologies.

[0063] Figure 3 This is a schematic diagram showing the black spots formed when adjacent copper conductors in a flexible bonded circuit board burn out due to a short circuit in a related technology.

[0064] Figure 4 This is a schematic diagram of a partial edge structure of a display module in an embodiment of the present invention;

[0065] Figure 5 This is a schematic diagram of a partial edge structure of another display module in an embodiment of the present invention;

[0066] Figure 6 This is a schematic diagram illustrating the operation of coating the flexible bonding circuit board with fluoride at the bend root in an embodiment of the present invention.

[0067] Figure 7 This is a schematic diagram of a partial edge structure of another display module in the related technology;

[0068] Figure 8 This is a cross-sectional view of the middle frame along a section perpendicular to the display panel in an embodiment of the present invention;

[0069] Figure 9a This is a schematic cross-sectional view of the assembly structure of the display module in an embodiment of the present invention;

[0070] Figure 9b This is a schematic diagram of the forces acting on the display modules when they are spliced ​​together to form a spliced ​​display screen in an embodiment of the present invention;

[0071] Figure 9c This is a mathematical model diagram of the forces acting on the display modules during the splicing of the display screen in this embodiment of the invention.

[0072] Figure 10a This is a partial structural diagram of the binding side edge of the display module in an embodiment of the present invention;

[0073] Figure 10b In this embodiment of the invention, when the protective cover is not assembled into the display module, along Figure 10a A structural cross-sectional view of the SS' section line;

[0074] Figure 10c This is a side view of the binding edge structure of the display module when a protective cover is assembled into the display module according to an embodiment of the present invention;

[0075] Figure 10d for Figure 10c Enlarged structural diagram of section X in the middle;

[0076] Figure 10e This is a force model diagram of the protective cover plate assembled into the display module in an embodiment of the present invention;

[0077] Figure 10f for Figure 10c Enlarged structural diagram of the Y-section;

[0078] Figure 10g This is a side view of the binding side edge structure of the display module when another protective cover is assembled into the display module in another embodiment of the present invention;

[0079] Figure 11a This is a schematic diagram showing the distribution of LED beads on the bottom wall of the backplate in an embodiment of the present invention;

[0080] Figure 11b This is a partial structural diagram of the display module in an embodiment of the present invention;

[0081] Figure 11c This is a schematic cross-sectional view of a partial structure of the display module from one perspective in an embodiment of the present invention;

[0082] Figure 12 This is a schematic cross-sectional view of a partial structure of the display module from another perspective in an embodiment of the present invention;

[0083] Figure 13a This is a partial structural cross-sectional view of the binding side edge of the display module in an embodiment of the present invention;

[0084] Figure 13b This is a partial structural cross-sectional view of the unbound side edge of the display module in an embodiment of the present invention;

[0085] Figure 14 This is a partial structural cross-sectional view of the bound side bezel area and the unbound side bezel area of ​​the display panel in an embodiment of the present invention;

[0086] Figure 15 This is a schematic diagram illustrating the principle of initial curing of adhesives by UV light irradiation.

[0087] The reference numerals in the attached figures are:

[0088] 1. Backlight module; 11. Mid-frame; 110. Support surface; 111. Boss; 12. Back plate; 121. Bottom wall; 122. Side wall; 2. Display panel; 21. Array substrate; 22. Alignment substrate; 23. First polarizer; 24. Second polarizer; 201. Display area; 202. Bezel area; 3. Flexible bonding circuit board; 4. Adhesive; 5. Fluoride layer; 6. First connector; 7. Peripheral circuit board; 8. Protective cover; 81. Bending part; 82. Rectangular toothed structure; 83. Middle part; 9. Second connector; 10. Lamp bead; 13. Light guide strip; 14. Diffuser plate; 15. Diffuser sheet; 16. First fastening tape; 17. Second fastening tape; 18. Black matrix; 19. Overflow adhesive; 20. Sealing adhesive. Detailed Implementation

[0089] To enable those skilled in the art to better understand the technical solution of the present invention, the following describes in further detail a display module, its preparation method, and a splicing display screen, in conjunction with the accompanying drawings and specific embodiments.

[0090] In related technologies, ULFD (1.7mm bezel width) and ELFD (0.88mm bezel width) series video walls (screens with narrow bezels use adhesive to bond the LCD panel and backlight panel) are composed of two or more display modules spliced ​​together. For example... Figure 1 As shown, each display module includes a backlight module 1 and a display panel 2 (such as an LCD panel). The backlight module 1 provides backlight for the display panel 2 during display. To ensure extremely narrow bezels, the display panel 2 and the backlight module 1 are bonded together using UV adhesive. The backlight module 1 includes a middle frame 11, which supports the four edges of the display panel 2. The top surface of the middle frame 11 is a support surface 110, on which adhesive is applied for bonding with the display panel 2.

[0091] In current products, because the width of the support surface 110 is generally less than 1mm, that is, the width of the adhesive surface is generally less than 1mm, the problem of adhesive overflow during and after bonding is common.

[0092] The display panel 2 includes an array substrate 21, a mating substrate 22 (such as a color filter substrate), and a flexible bonding circuit board 3 (COF, i.e., a chip-on-film). The flexible bonding circuit board 3 is bonded to at least one edge of the array substrate 21. The flexible bonding circuit board 3 is bent downward from the display side of the array substrate 21 through the corresponding edge end face of the array substrate 21 to the outside of the middle frame 11, and is electrically connected to a peripheral circuit board disposed on the outside of the middle frame 11. The peripheral circuit board is used to provide drive signals (including data signals, scan signals, etc.) and power signals to the array substrate 21 through the flexible bonding circuit board 3. The physical seam of the splicing screen is an important physical parameter. In order to ensure a small seam width, the bending radius of the bending root of the flexible bonding circuit board 3 (the part located on the outside of the edge end face of the array substrate) needs to be less than 0.3 mm. Thus, the bent root of the flexible bonding circuit board 3 comes into contact with the overflow adhesive 19 on the support surface 110, forming a relatively sealed space Q. In a high-temperature and high-humidity environment, moisture enters the relatively sealed space Q and accumulates into water droplets, adhering to the contact position between the flexible bonding circuit board 3 and the overflow adhesive 19. Since sulfur (S) foreign matter in the air is also commonly present on the surface of the flexible bonding circuit board 3 and the overflow adhesive 19, under the action of the product being powered on, sulfur elements penetrate into the protective film (SR) covering the copper conductors in the flexible bonding circuit board 3, forming a galvanic cell reaction, causing copper migration on the copper conductors. When the copper migration reaches a certain extent, a short circuit occurs between adjacent copper conductors in the flexible bonding circuit board 3, resulting in line defects in the corresponding display area.

[0093] The specific principle of copper migration in copper conductors of flexible bonded circuit boards is as follows: Figure 2 As shown, after the display panel 2 and the support surface 110 of the middle frame 11 are bonded together with UV adhesive, there is excess adhesive 19 outside the bonding surface. Moisture accumulates at the contact point between the excess adhesive 19 and the protective film (SR) of the copper conductor, and there are sulfur-containing foreign objects at this location. The water and sulfur foreign objects connect to the middle frame 11 to form a cathode. Because the protective film (SR) of the copper conductor is not waterproof or sulfur-resistant, it forms an electrochemical reaction with the copper conductor (as the anode) when electricity is applied. Copper (Cu) loses electrons and is oxidized, while sulfur (S) gains electrons to form CuS or Cu2S, causing defects to form at the edges of the copper conductors within the flexible bonding circuit board 3, thereby accelerating copper migration on the copper conductors. When copper migration or the electrolytic solution causes a short circuit between two adjacent copper conductors, overcurrent burns out, forming black spots (such as...). Figure 3 (As shown) and copper wires connected in a Y-shape.

[0094] To address the issue of copper migration on internal copper conductors caused by moisture absorption from contact with excess adhesive in flexible bonding circuit boards in related technologies, embodiments of the present invention provide a display module, such as... Figure 4As shown, the display includes a backlight module 1 and a display panel 2. The display panel 2 includes a display side and a back side, which are opposite to each other. The backlight module 1 includes a middle frame 11, which is located on the back side of the display panel 2 and surrounds the four edges of the display panel 2 to support the four edges of the display panel 2. The display module also includes a flexible bonding circuit board 3, which is bonded to at least one edge of the display side of the display panel 2. The flexible bonding circuit board 3 is bent from the display side of the display panel 2 to the outside of the corresponding side middle frame 11. The support surface 110 of the middle frame 11 is bonded to the display panel 2 by an adhesive 4. The orthographic projection of the adhesive 4 on the display panel 2 is located in the overlapping area of ​​the orthographic projection of the support surface 110 and the display panel 2.

[0095] The display panel 2 includes an array substrate 21 and a mating substrate 22, which are mated together. The array substrate 21 is located on the back side of the display panel 2, and the mating substrate 22 is located on the display side of the display panel 2. Pixel circuits are disposed on the array substrate 21, and the mating substrate 22 is a color filter substrate (e.g., if the display panel 2 is a liquid crystal panel) or a cover plate (e.g., if the display panel 2 is an OLED panel). The array substrate 21 is bonded to the support surface 110 of the middle frame 11 using adhesive 4. In this embodiment, a first polarizer 23 is disposed on the side of the array substrate 21 facing away from the mating substrate 22, and a second polarizer 24 is disposed on the side of the mating substrate 22 facing away from the array substrate 21; that is, in this embodiment, the display panel 2 is a liquid crystal panel.

[0096] Optionally, the flexible bonding circuit board 3 is bonded to adjacent two side edges of the display panel 2. For example, the flexible bonding circuit board 3 bonded to one side edge of the display panel 2 is used to provide data signals and power signals to the display panel 2; correspondingly, this side edge of the display module is the DP side edge, and the side edge opposite to the DP side edge is the DPO side edge. The flexible bonding circuit board 3 bonded to the other side edge of the display panel 2 is used to provide gate scan signals to the display panel 2; correspondingly, this side edge of the display module is the GP side edge, and the side edge opposite to the GP side edge is the GPO side edge.

[0097] Optionally, there may be multiple flexible bonding circuit boards 3 located on the DP side edge; there may also be multiple flexible bonding circuit boards 3 located on the GP side edge; in order to meet the display driving requirements of larger size display modules.

[0098] Optionally, the flexible bonding circuit board 3 is bonded to the display side edge of the array substrate 21. The bonding area of ​​the array substrate 21 is not covered by the mating substrate. A protective film is formed in the bonding area of ​​the array substrate 21 to protect the bonding end.

[0099] In this embodiment, the outer side of the middle frame 11 refers to the side of the middle frame 11 that is away from the cavity it encloses.

[0100] In this embodiment, by positioning the orthographic projection of the adhesive 4 on the display panel 2 at the overlapping area of ​​the orthographic projection of the support surface 110 and the display panel 2, there is no excess adhesive around the bonding surface of the support surface 110 of the middle frame 11 and the display panel 2 after the display panel 2 and the backlight module 1 are bonded together. This prevents the flexible bonding circuit board 3, which is bent to the outside of the middle frame 11, from contacting the excess adhesive and forming a sealed space. This prevents moisture and sulfur foreign matter in the air from entering the sealed space and invading into the flexible bonding circuit board 3. Consequently, it prevents moisture and sulfur foreign matter from forming a galvanic cell reaction with the electrically conductive metal wires (such as copper wires) in the flexible bonding circuit board 3, preventing metal migration in the metal wires, and ultimately preventing short circuits between adjacent metal wires in the flexible bonding circuit board 3, thus ensuring the display quality of the display module.

[0101] Optionally, such as Figure 5 As shown, the orthographic projection of adhesive 4 on the display panel 2 is located at the periphery of the area where the orthographic projections of the support surface 110 and the display panel 2 overlap, and the flexible bonding circuit board 3 does not contact the adhesive 4 closest to it. That is, a small amount of adhesive 4 may overflow to the periphery of the area where the orthographic projections of the support surface 110 and the display panel 2 overlap, but the flexible bonding circuit board 3 does not contact the adhesive 4 closest to it, thus preventing the formation of a closed space. This avoids the metal migration of metal wires in the flexible bonding circuit board 3 caused by moisture and sulfur foreign matter entering the closed space, and ultimately avoids short circuits between adjacent metal wires in the flexible bonding circuit board 3, ensuring the display quality of the display module.

[0102] Optionally, such as Figure 4 and Figure 5 As shown, a fluorinated layer 5 is provided on the side of the flexible bonding circuit board 3 facing the middle frame 11; the fluorinated layer 5 at least covers the side of the flexible bonding circuit board 3 facing the middle frame 11 at the bending root; the bending root is the part of the flexible bonding circuit board 3 from the bending point P to the position flush with the adhesive 4.

[0103] The main reason for metal (such as copper) migration in the metal conductors within the flexible bonding circuit board 3 is the accumulation of moisture on the protective film surface of the metal conductors within the flexible bonding circuit board 3. This moisture carries sulfur foreign matter from the air into the metal conductors covered by the protective film. A fluorinated agent layer 5 is provided on the side of the flexible bonding circuit board 3 facing the middle frame 11 at the bending root, which can isolate moisture at the bending root of the flexible bonding circuit board 3, thereby preventing moisture from carrying sulfur foreign matter into the metal conductors within the flexible bonding circuit board 3, and thus avoiding metal migration on the metal conductors.

[0104] Optionally, the fluorinated layer 5 can be made of 8200UR material and is applied to the side of the flexible bonding circuit board 3 facing the middle frame 11 using a round-headed brush (e.g., BON-102).

[0105] Optionally, the fluorinating agent layer 5 can be applied before the display panel 2 is bonded to the support surface 110, that is, after the flexible bonding circuit board 3 is bonded to the display panel 2. Figure 6 As shown, the display panel 2 is placed upside down on the worktable, with the array substrate 21 facing upwards, allowing the flexible bonding circuit board 3 to hang naturally. Then, a round-headed brush is used to apply fluorinating agent to the side of the flexible bonding circuit board 3 facing the middle frame 11 at the bend root, forming a fluorinating agent layer 5. This fluorinating agent coating of the display panel 2 in its standalone state ensures comprehensive and uniform fluorinating agent coating at the bend root of the flexible bonding circuit board 3, resulting in higher work efficiency and less damage caused by product turnover.

[0106] Optionally, the orthographic projection of the support surface 110 onto the display panel 2 is located on the display panel 2. That is, the display panel 2 covers the entire support surface 110.

[0107] Optionally, the outer edge of the orthographic projection of the support surface 110 onto the display panel 2 coincides with the corresponding side edge of the display panel 2. Here, the outer edge of the support surface 110 refers to the side edge of the support surface 110 that is furthest from the central region of the display panel 2.

[0108] Among them, such as Figure 7 As shown, when the orthographic projection of the support surface 110 onto the display panel 2 does not completely fall onto the display panel 2, that is, when the display panel 2 does not completely cover the support surface 110, after the display panel 2 and the support surface 110 of the middle frame 11 are bonded together with adhesive 4, the height of the overflow adhesive from the support surface 110 beyond the support surface 110 is H = d1 (the width of the exposed support surface 110 outside the display panel 2) + h1 (the width of the portion of the overflow adhesive protruding beyond the outer side of the middle frame 11). During the bonding process between the display panel 2 and the support surface 110, if the bonding position of the display panel 2 shifts, a portion of the support surface 110 will be exposed (i.e., not covered by the display panel 2). The larger the size of the exposed portion of the support surface 110, the more severe the overflow adhesive, and the higher the risk of line defects in the display module. In the bonding process between the display panel 2 and the support surface 110 of the middle frame 11, the standard setting is that the support surface 110 of the middle frame 11 cannot exceed the edge of the display panel 2, that is, either the edge of the display panel 2 exceeds the outer edge of the support surface 110, or the edge of the display panel 2 is aligned and coincides with the outer edge of the support surface 110.

[0109] Optionally, in order to ensure the fitting accuracy between the display panel 2 and the support surface 110, the camera positioning and gripping reference is the outer edge of the support surface 110 of the middle frame 11, and the calibration is performed twice to ensure high-precision fitting.

[0110] Optionally, such as Figure 8 As shown, the width of the support surface 110 of the middle frame 11 ranges from 0.8 to 1.1 mm; the width of the support surface 110 is the dimension of the support surface 110 in the direction Z along the edge of the display panel 2 toward the middle area of ​​the display panel 2.

[0111] Optionally, the width of the support surface 110 of the GP side edge frame 11 of the display module is 1.0 mm, and the width of the support surface 110 of the GPO side edge frame 11 of the display module is 0.8 mm. This setting ensures optimal improvement of the rainbow lines on the GP and GPO side edges of the display module without the risk of delamination between the display panel 2 and the support surface 110. Optionally, the width of the support surface 110 of the DP side edge frame 11 of the display module is 1.0 mm, and the width of the support surface 110 of the DPO side edge frame 11 of the display module is 1.0 mm. The width settings of the support surfaces 110 of the frame 11 on each side edge of the display module ensure both firm support for the display panel 2 and a firm fit with the display panel 2.

[0112] Optionally, such as Figure 8 and Figure 9a As shown, the backlight module 1 also includes a back plate 12, which is located on the side of the middle frame 11 facing away from the display panel 2. The cross-sectional shape of the middle frame 11 perpendicular to the display panel 2 is an inverted U-shape. The back plate 12 includes a bottom wall 121 and a side wall 122. The side wall 122 surrounds the bottom wall 121 and is connected to the bottom wall 121 to form an L-shape. The inverted U-shaped opening of the middle frame 11 faces the back plate 12. The side wall 122 is partially embedded in the inverted U-shaped opening of the middle frame 11, and the side wall 122 is fixedly connected to the outer side wall of the inverted U-shaped middle frame 11 by a first connector 6. The display module also includes a peripheral circuit board 7, which is fixed to the outer side surface of the side wall 122. The flexible bonding circuit board 3 extends to connect with the peripheral circuit board 7.

[0113] The first connector 6 can be a screw or bolt. The back plate 12 is a cavity formed by the bottom wall 121 and the side wall 122, and the outer side of the side wall 122 refers to the side of the side wall 122 that faces away from the cavity. The flexible bonding circuit board 3 is connected to the peripheral circuit board 7, enabling the peripheral circuit board 7 to provide drive signals (such as data signals and gate scan signals) and power signals to the display panel 2 through the flexible bonding circuit board 3.

[0114] In this embodiment, as Figures 9a-9cAs shown, the bottom of the display panel 2 is coated with adhesive 4 and adhered to the support surface 110 of the middle frame 11. The support surface 110 is located at the top of the middle frame 11. The middle frame 11 has a relatively high overall height and is easily deformed under pressure. To improve the deformation resistance of the middle frame 11, it is designed as an inverted U-shape. The bottom wall 121 of the back panel 12 is connected to the side wall 122 to form an L-shape. The side wall 122 is partially embedded in the inverted U-shaped opening of the middle frame 11, and the side wall 122 and the outer side wall of the inverted U-shaped middle frame 11 are fixedly connected by the first connector 6. When this display module is used in a splicing display, the side where the middle frame 11 is located will be subjected to a compressive force F1, which is applied to the top outer wall of the middle frame 11. The splicing display screen generates heat during operation. The thermal expansion rate of the display panel 2 is less than that of the middle frame 11. Because the middle frame 11 expands more, it experiences a tensile force F2 from the display panel 2. F2 is applied to the middle frame 11 support surface 110 via the adhesive 4. After the middle frame 11 and the side wall 122 of the back panel 12 are fastened together by the first connector 6, a [structure / structure] is formed. Figure 9c The diagram shows a triangular mathematical model of the stress on the middle frame 11. This triangular mathematical model of the stress on the middle frame 11 is a robust mathematical model that ensures the overall structure of the display module remains largely unchanged when subjected to an inward horizontal thrust, meaning the overall structure of the display module has high stability.

[0115] Optionally, such as Figure 10a , Figure 10b , Figure 10c and Figure 10d As shown, the display module also includes a protective cover plate 8, which is disposed on the side of the peripheral circuit board 7 away from the side wall 122. The upper end of the protective cover plate 8 extends to be flush with the display side surface of the display panel 2. The middle part 83 of the protective cover plate 8 covers the peripheral circuit board 7. The lower end of the protective cover plate 8 forms an L-shaped bend 81 with a bending angle θ greater than 90° and less than 180°. The lower end of the bend 81 away from the middle part 83 of the protective cover plate 8 is fixedly connected to the corresponding side wall 122 by a second connector 9.

[0116] Optionally, the second connector 9 can be a screw or bolt. When the lower end plate wall of the portion 83 of the bent part 81 away from the middle of the protective cover plate 8 is not fixedly connected to the corresponding side wall 122 by the second connector 9, the bending angle θ of the bent part 81 is greater than 90° and less than 180°; when the lower end plate wall of the portion 81 away from the middle of the protective cover plate 83 is fixedly connected to the corresponding side wall 122 by the second connector 9, because the side wall 122 is a vertical plane, under the squeezing action of the side wall 122, the bending angle θ of the bent part 81 becomes 90° or approximately 90°.

[0117] Optionally, such as Figure 10a and Figure 10bAs shown, the upper end of the protective cover plate 8 is formed into a plurality of rectangular tooth-like structures 82 spaced apart, and the flexible bonding circuit board 3 is exposed in the spaced area between the rectangular tooth-like structures 82; the rectangular tooth-like structures 82 are bent at 1.5° to 2° (i.e., angle α) relative to the middle part 83 of the protective cover plate 8 facing the edge end face near the display panel 2.

[0118] In this embodiment, the upper end of the protective cover 8 corresponding to the edge face of the display panel 2 adopts a unique rectangular toothed structure 82 design. When the display module is used to splice the display screen, the side of the display module is subjected to a large compressive force. The compressive force acts directly on the edge face of the display panel 2 through the upper end of the protective cover 8, which may damage the flexible bonding circuit board 3. The rectangular toothed structure 82 can play a supporting role under the action of this compressive force. At the same time, since there is no protective cover 8 at the position of the flexible bonding circuit board 3, it can prevent the flexible bonding circuit board 3 from being damaged by the protective cover 8. In addition, the rectangular toothed structure 82 is bent at 1.5° to 2° relative to the middle part 83 of the protective cover 8 towards the edge face of the display panel 2. During the fixed connection of the second connector 9, if Figure 10e and Figure 10f As shown, the protective cover 8 is subjected to an inward pushing force FB applied by the second connector 9 at point B. The protective cover 8 contacts the side wall 122 of the back plate 12 at point C. At point C, the side wall 122 of the back plate 12 generates an outward reaction force FC on the protective cover 8. The pushing force FB and the reaction force FC form a force lever, generating an inward squeezing force at point A, where the protective cover 8 contacts the edge end face of the display panel 2. This ensures that the rectangular toothed structure 82 of the protective cover 8 fits tightly with the edge end face of the display panel 2, and there is no gap between the rectangular toothed structure 82 and the edge end face of the display panel 2, ensuring the assembly firmness and stability of the display module.

[0119] It should be noted that, as Figure 10g As shown, if the rectangular toothed structure 82 does not have a bending angle of 1.5° to 2° relative to the middle part 83 of the protective cover plate 8 facing the edge end face near the display panel 2, and the bending part 81 does not form a bending angle greater than 90° and less than 180°, then during the actual assembly process of the protective cover plate 8, if the rectangular toothed structure 82 and the edge end face of the display panel 2 only contact at position D due to fluctuations in the size of the protective cover plate 8 or the fitting accuracy of the display panel 2, then under the action of the lever principle, a gap will be generated between the rectangular toothed structure 82 and the edge end face of the display panel 2, which will seriously affect the assembly firmness and stability of the display module.

[0120] Optionally, such as Figure 11a , Figure 11b and Figure 11cAs shown, the display module also includes multiple LEDs 10, which are arranged in an array on the bottom wall 121 of the back panel 12. The bottom wall 121 includes a first area S1, a second area S2, and a third area S3. The second area S2 and the first area S1 are arranged around the third area S3. The spacing between adjacent LEDs 10 in the first area S1 is smaller than the spacing between adjacent LEDs 10 in the second area S2. The spacing between adjacent LEDs 10 in the second area S2 is larger than the spacing between adjacent LEDs 10 in the third area S3. The spacing between adjacent LEDs 10 in the first area S1 is smaller than the spacing between adjacent LEDs 10 in the third area S3.

[0121] In this embodiment, the LED beads 10 are arranged at non-equidistant intervals to prevent bright edges from appearing on the display module, while ensuring the uniformity of brightness of the displayed image.

[0122] Optionally, in some embodiments, the spacing between adjacent LED beads 10 in the first zone S1 is 54.5 mm; the spacing between adjacent LED beads 10 in the second zone S2 is 90 mm; and the spacing between adjacent LED beads 10 in the third zone S3 is 74.674 mm. (Refer to...) Figure 11c To achieve the desired spacing between adjacent LED beads 10 within the first zone S1, second zone S2, and third zone S3, the upper section of the middle frame 11 near the rectangular toothed structure 82 has a cross-sectional length of 8mm, the middle section connected to the upper section has an arc radius of 10mm, and the lower section connected to the middle section has a cross-sectional length of 15.3mm. The distance between the inner side of the middle frame 11 and the center of the light-emitting surface of the nearest LED bead 10 is 18.3mm.

[0123] Optionally, such as Figure 4 and Figure 12 As shown, the backlight module also includes a light guide strip 13, a diffuser plate 14, and a diffuser sheet 15; the light guide strip 13, the diffuser plate 14, and the diffuser sheet 15 are located within the space formed by the back plate 12 and the middle frame 11, and are stacked sequentially away from the LED beads 10; the light guide strip 13 is distributed around the four edges of the display panel 2; the middle frame 11 includes a boss 111, which is located between the support surface 110 and the inverted U-shaped opening; the light guide strip 13 is located on the boss 111 and is fixedly connected to the boss 111; the diffuser sheet 15 includes at least two sub-diffuser sheets, which are stacked sequentially on the side of the diffuser plate 14 away from the LED beads 10; the diffuser plate 14 is spaced apart from the LED beads 10.

[0124] The light guide strip 13 is translucent and may be made of materials such as PET. The light guide strip 13 is bonded to the protrusion and to the diffuser plate 14 using double-sided adhesive. The diffuser plate 14 and diffuser sheet 15 can homogenize the light emitted by the LED beads 10, making the light incident on the display panel 2 more uniform. The light guide strip 13 effectively prevents the problem of dark frames during display caused by excess adhesive on the bonding surface between the display panel 2 and the support surface 110 of the middle frame 11. Furthermore, as a light-uniforming film layer, the diffuser plate 14 and diffuser sheet 15, compared to the optical processing layers with multiple stacked optical film layers in the disclosed technology, can reduce the material cost of the display module and also reduce its weight, which is beneficial for using the display module in splicing displays.

[0125] Optionally, such as Figure 13a and Figure 13b As shown, the display module also includes a first fastening tape 16 and a second fastening tape 17; the second fastening tape 17 is attached to the side of the protective cover plate 8 away from the side wall 122, and the upper side edge of the second fastening tape 17 is flush with the display side surface of the display panel 2; the first fastening tape 16 is attached to the side of the second fastening tape 17 away from the protective cover plate 8, and the first fastening tape 16 also extends to cover the display side frame of the display panel 2; the first fastening tape 16 is also attached to the outside of the middle frame 11 on the non-bonding side of the display panel 2, and the upper side edge of the first fastening tape 16 on this side is flush with the display side surface of the display panel 2.

[0126] The first fastening tape 16 is a light-shielding tape. The second fastening tape 17 and the first fastening tape 16 are sequentially applied to the outer side of the protective cover plate 8 on the bonding side of the display module (i.e., the side where the flexible bonding circuit board 3 is located), making the structural assembly of the bonding side of the display module more robust and stable. The first fastening tape 16 is also applied to the outer side of the middle frame 11 on the non-bonding side of the display module, making the structural assembly of the non-bonding side of the display module more robust and stable.

[0127] Optionally, such as Figure 13a As shown, on the bonding side edge of the display module (such as the DP side edge and the GP side edge), the bezel width of the display side of the display module is composed of the thickness a of the first fastening tape 16, the thickness b of the second fastening tape 17, the thickness c of the protective cover plate 8, and the distance d between the edge of the display panel 2 and the display area. Optionally, the thickness a of the first fastening tape 16 is 0.05 mm; the thickness b of the second fastening tape 17 is 0.1 mm; the thickness c of the protective cover plate 8 is 0.4 mm; and the distance d between the edge of the display panel 2 and the display area (i.e., area AA) is 1.2 mm.

[0128] Optionally, such as Figure 13bAs shown, on the non-bonded side edge of the display module (such as the DPO side edge and GPO side edge), the bezel width of the display side of the display module is determined by the thickness g of the first fastening tape 16 and the distance f between the edge of the display panel 2 and the display area. Optionally, the thickness g of the first fastening tape 16 is 0.05 mm; the distance f between the edge of the display panel 2 and the display area (i.e., area AA) is 0.8 mm. Furthermore, on the non-bonded side edge of the display module, the orthographic projection of the support surface 110 of the middle frame 11 onto the display panel 2 can overlap with a portion of the display area of ​​the display panel 2, such as a 0.2 mm width e of the overlap between the support surface 110 and the display area of ​​the display panel 2. However, the overlap between the support surface 110 and the display area of ​​the display panel 2 is translucent and not within the bezel area of ​​the display module.

[0129] Optionally, such as Figure 14 As shown, the display panel 2 includes a display area 201 and a bezel area 202, such that the bezel area 202 is shielded by a black matrix 18 disposed on the mating substrate 22. Optionally, in the bonding side bezel area 202 of the display panel 2 (such as the DP side bezel area and the GP side bezel area), the width of the black matrix 18 is 1.2 mm; in the non-bonding side bezel area 202 of the display panel 2 (such as the DPO side bezel area and the GPO side bezel area), the width of the black matrix 18 is 0.8 mm. The array substrate 21 and the mating substrate 22 are bonded together in the mating bezel area 202 by a sealing adhesive 20.

[0130] Based on the above structure of the display module, this embodiment also provides a method for manufacturing the display module, including: manufacturing a backlight module and a display panel respectively;

[0131] Apply adhesive to the support surface of the middle frame in the backlight module;

[0132] The display panel is placed on the support surface to achieve bonding between the backlight module and the display panel.

[0133] In this preparation method, the adhesive is sprayed through a spray valve with a nozzle diameter of 0.1–0.3 mm. During spraying, the spray valve temperature ranges from 100℃ to 120℃; the spray valve striker frequency ranges from 900 to 1000 Hz; the adhesive application speed on the edge of the bonding side (i.e., the COF side) of the display module ranges from 140 to 150 mm / s; the adhesive application speed on the edge of the non-bonding side (i.e., the non-COF side) of the display module ranges from 90 to 100 mm / s; and the initial curing energy of the adhesive before bonding the display panel to the backlight module ranges from 1000 to 1100 mJ / cm². 2 After the display panel and backlight module are bonded together, the pressure holding weight of the adhesive is 0 kg.

[0134] In this preparation method, the adhesive spraying process is as follows: first, clean the middle frame support surface; then spray the adhesive onto the support surface through the spray valve; next, perform initial curing of the adhesive sprayed onto the support surface; finally, align and bond the support surface with the display panel.

[0135] Optionally, the cleaning process for the middle frame support surface is as follows: first, use a cotton swab dipped in 5% NaOH (sodium hydroxide) solution to wipe the support surface; then, use a cotton swab dipped in clean water to wipe the support surface.

[0136] In this embodiment, to ensure minimal or no adhesive overflow after the display panel is bonded to the mid-frame support surface, the adhesive-related process parameters were determined as follows. The adhesive-related process parameter tests were conducted using the HH-S1000 model display module as an example, with B-100 adhesive as the test subject.

[0137] Optionally, the spray valve temperature is 120℃. If the temperature is too high, the adhesive becomes more fluid, resulting in significant adhesive overflow on both the inner and outer sides of the support surface after bonding. Inner overflow will obscure edge pixels, affecting the display effect and seam coverage; outer overflow protrudes from the edge of the display panel, affecting not only the appearance and seam coverage of the spliced ​​display, but also creating a relatively enclosed space with the flexible bonding circuit board, causing metal migration on the metal conductors within the flexible circuit board (such as copper migration on copper conductors), leading to poor line quality in the display module's display area.

[0138] Optionally, the nozzle firing pin frequency is 1000Hz. The nozzle firing pin frequency is directly related to the amount of adhesive applied to the support surface. A higher firing pin frequency results in a larger amount of adhesive applied, but this increased amount of adhesive will exacerbate the overflow of adhesive on both the inner and outer sides. A lower firing pin frequency results in a smaller amount of adhesive applied, reducing the overflow of adhesive on both the inner and outer sides; however, the nozzle spraying method is to apply adhesive in dots, and a lower firing pin frequency results in an uneven, jagged adhesive line, affecting the surrounding display effect. After multiple tests, a firing pin frequency of 1000Hz provides the best overall performance.

[0139] In this embodiment, the adhesive application speed refers to the moving speed of the spray valve relative to the adhesive surface of the product during the adhesive application process. The adhesive application speed also directly affects the amount of adhesive applied, and the amount of adhesive applied directly affects the degree of adhesive overflow on the inner and outer sides of the support surface; the adhesive application speed also affects the adhesive thickness, and the greater the adhesive thickness, the less likely the adhesive separation problem will occur. In this embodiment of the invention, different adhesive application speeds are used for the bonding side edge and the non-bonding side edge of the display module for the following reasons: ① Adhesive overflow on the bonding side edge will form a relatively closed space with the flexible bonding circuit board, causing moisture accumulation, and then metal migration on the metal conductors inside the flexible circuit board will occur. However, the bonding side edge has a certain tension provided by the flexible bonding circuit board, so the risk of adhesive separation is smaller compared to the non-bonding side edge; ② The non-bonding side edge has no other components to provide tension, making it more prone to adhesive separation problems.

[0140] Optionally, the adhesive application speed on the bonding side edge of the display module is 150 mm / s, and the adhesive application speed on the non-bonding side edge of the display module is 100 mm / s.

[0141] In this embodiment of the invention, the initial curing of the adhesive is achieved by UV light irradiation. UV light irradiation is used to accelerate the initial curing and shaping of the adhesive, maintaining a certain aspect ratio of the adhesive line and ensuring sufficient adhesive thickness and minimal overflow on both the inner and outer sides. Excessive or insufficient UV light irradiation will affect the adhesive strength and thickness, as explained below:

[0142] Scenario 1: When UV light irradiates within the range of light energy parameters: such as Figure 15 As shown,

[0143] ①When exposed to UV light, the photoinitiator I2 in the adhesive is released into free radicals;

[0144] ② Free radicals break the double bonds of acrylic monomers in the glue, causing them to grow into long polymer chains;

[0145] ②The polyurethane monomers in the adhesive react with moisture to grow into long chains;

[0146] ③ The long acrylic chain and the long polyurethane chain are physically intertwined to form a mesh, ensuring a high elongation rate of the adhesive thread (the elongation rate is about 10 times according to Sekisui Laboratory's self-test).

[0147] Scenario 2: When UV light exposure is insufficient (i.e., UV light irradiation is too low or the exposure time is too short):

[0148] ① When irradiated with UV light, the amount of free radicals released by the photoinitiator I2 in the adhesive is insufficient;

[0149] ② The number of free radicals is insufficient, and only some acrylic monomers grow into long polymer chains;

[0150] ③ After acrylic and polyurethane long chains are physically intertwined, they cannot form a complete network, and the adhesive threads are prone to breakage when stretched.

[0151] Scenario 3: When UV light exposure is excessive (i.e., excessive UV light irradiation or prolonged exposure time):

[0152] ①When exposed to UV light, the photoinitiator I2 in the adhesive fully releases free radicals;

[0153] ② Due to excessive free radical activity, the acrylic monomers on the adhesive surface rapidly grow into long chains, causing premature curing and the formation of a protective film.

[0154] ③ Moisture cannot penetrate the adhesive, resulting in insufficient moisture reaction of polyurethane monomers;

[0155] ④ After the acrylic long chain and the polyurethane long chain are physically intertwined, they cannot form a complete network, and the adhesive threads are prone to breakage when stretched.

[0156] Optionally, the initial curing energy (i.e., UV light exposure) of the adhesive is 1100 mJ / cm². 2 This ensures sufficient adhesive thickness and high bonding strength, while minimizing adhesive overflow on the inner and outer sides of the mid-frame support surface (overflow width less than 0.1mm).

[0157] In this embodiment, the pressure holding of the adhesive is performed after the adhesive is applied to the support surface and the display panel is attached to the support surface of the backlight module's middle frame. Weights are then applied around the front (display side) of the display panel to press the initial adhesive lines apart to a certain extent, ensuring sufficient contact between the adhesive and the display panel and the middle frame support surface. However, the adhesive has already been heated during spraying, resulting in high fluidity. Actual use of the adhesive in the display module shows that solely pursuing high adhesion strength can lead to severe adhesive overflow on both the inner and outer sides of the support surface.

[0158] Optionally, the pressure holding weight of the adhesive is adjusted to 0 kg, meaning that the initial adhesive lines can be fully pressed open by the weight of the display panel itself.

[0159] In this embodiment, in the manufacturing environment of the display module, foreign matter is easily adsorbed onto the surface of the flexible bonding circuit board and the overflow adhesive. In a high-temperature and high-humidity environment, water droplets formed by the accumulation of water vapor in the sealed space formed by the contact between the flexible bonding circuit board and the overflow adhesive seep into the protective film (SR) covering the metal conductors in the flexible bonding circuit board. This water droplets can carry elements such as sulfur (i.e., sulfur foreign matter) from the environmental foreign matter, causing metal migration of the metal conductors in the flexible bonding circuit board. Therefore, comprehensive foreign matter control is required for the production environment of the display module to prevent the content of foreign matter such as sulfur.

[0160] The display module provided in this embodiment of the invention ensures that the orthographic projection of the adhesive on the display panel is located in the overlapping area of ​​the orthographic projection of the support surface and the display panel. This prevents excess adhesive from overflowing around the bonding surface between the support surface of the middle frame and the display panel after the display panel and the backlight module are bonded together. This avoids the flexible bonding circuit board bent to the outside of the middle frame from contacting the excess adhesive and forming a sealed space. Consequently, it prevents moisture and sulfur foreign matter in the air from entering the sealed space and intruding into the flexible bonding circuit board. This, in turn, prevents moisture and sulfur foreign matter from forming a galvanic cell reaction with the electrically conductive metal wires (such as copper wires) in the flexible bonding circuit board, preventing metal migration in the metal wires. Ultimately, it prevents short circuits between adjacent metal wires in the flexible bonding circuit board, ensuring the display quality of the display module.

[0161] The display module provided by this invention can be any product or component with display function, such as LCD panel, LCD TV, OLED panel, OLED TV, OLED billboard, monitor, mobile phone, navigator, etc.

[0162] This invention also provides a splicing display screen, including at least two display modules as described in the above embodiments, with at least two display modules spliced ​​together; the display module includes a bonded side edge and an unbonded side edge, and a flexible bonding circuit board in the display module is disposed on the bonded side edge; the bonded side edge and the unbonded side edge of the display module are spliced ​​together.

[0163] Optionally, the seam width of the display panels in the display module ranges from 1.2 to 2.0 mm. The seam width is the sum of the widths of the bound side bezel area of ​​one display panel and the unbound side bezel area of ​​the other display panel in the two spliced ​​display modules; that is, the seam width is the sum of the widths of the black matrix in the bound side bezel area of ​​one display panel and the unbound side bezel area of ​​the other display panel. Optionally, the seam width is 2.0 mm.

[0164] Optionally, the seam width of the display modules ranges from 1.8 to 2.6 mm. The seam width is the sum of the border width of the bound edge display side of one of the two spliced ​​display modules and the border width of the unbound edge display side of the other display module. Optionally, the seam width of the display modules is 2.6 mm.

[0165] The splicing display screen provided in this embodiment of the invention, by adopting the display module in the above embodiment, can not only achieve an extremely narrow bezel in the splicing display screen, but also avoid short circuits between adjacent metal wires in the flexible bonding circuit board, thus ensuring the display quality of the splicing display screen.

[0166] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A display module, comprising a backlight module and a display panel, the display panel comprising a display side and a back side, the display side and the back side being opposite to each other; The backlight module includes a middle frame, which is located on the back side of the display panel and surrounds the four edges of the display panel to provide support for the four edges of the display panel. The display module further includes a flexible bonding circuit board, which is bonded to at least one edge of the display side of the display panel; the flexible bonding circuit board is bent from the display side of the display panel to the outside of the corresponding side of the middle frame; The supporting surface of the middle frame is bonded to the display panel with adhesive. Its features are, The orthographic projection of the adhesive on the display panel is located in the area where the orthographic projections of the support surface and the display panel overlap. A fluorinated layer is provided on the side of the flexible bonding circuit board facing the middle frame; The fluorinated layer at least covers the side of the flexible bonded circuit board facing the middle frame at the bend root; The bending root is the portion of the flexible bonding circuit board from the bending point to the position flush with the adhesive.

2. The display module according to claim 1, characterized in that, The orthographic projection of the supporting surface onto the display panel is located on the display panel.

3. The display module according to claim 2, characterized in that, The outer edge of the orthographic projection of the support surface onto the display panel coincides with the corresponding side edge of the display panel.

4. The display module according to any one of claims 1-3, characterized in that, The width of the middle frame support surface ranges from 0.8 to 1.1 mm; The width of the support surface is the dimension of the support surface along the edge of the display panel toward the center area of ​​the display panel.

5. The display module according to any one of claims 1-3, characterized in that, The backlight module also includes a back plate, which is located on the side of the middle frame opposite to the display panel; The cross-sectional shape of the middle frame perpendicular to the display panel is an inverted U-shape; The back panel includes a bottom wall and a side wall, the side wall surrounds the bottom wall and the side wall is connected to the bottom wall to form an L-shaped shape; The inverted U-shaped opening of the middle frame faces the back plate, and the side wall is partially embedded in the inverted U-shaped opening of the middle frame. The side wall and the outer side wall of the inverted U-shaped middle frame are fixedly connected by a first connector. The display module also includes a peripheral circuit board, which is fixed to the outer side surface of the sidewall; The flexible bonding circuit board extends to connect with the peripheral circuit board.

6. The display module according to claim 5, characterized in that, It also includes a protective cover plate disposed on the side of the peripheral circuit board away from the side wall, the upper end of the protective cover plate extending to be flush with the display side surface of the display panel; The middle portion of the protective cover plate correspondingly shields the outer circuit board; The lower end of the protective cover plate forms an L-shaped bend with a bending angle greater than 90° and less than 180°. The lower end of the bend plate away from the middle part of the protective cover plate is fixedly connected to the corresponding side wall by a second connector.

7. The display module according to claim 6, characterized in that, The upper end of the protective cover is formed with multiple rectangular tooth-like structures spaced apart. The flexible bonding circuit board is exposed in the spaced area between the rectangular toothed structures; The rectangular toothed structure is bent at 1.5° to 2° relative to the middle part of the protective cover towards the edge face of the display panel.

8. The display module according to claim 5, characterized in that, It also includes multiple LED beads, which are arranged in an array on the bottom wall of the back plate; The bottom wall includes a first zone, a second zone, and a third zone, with the second zone and the first zone sequentially surrounding the periphery of the third zone; The spacing between adjacent LED beads in the first zone is smaller than the spacing between adjacent LED beads in the second zone; The spacing between adjacent LED beads in the second zone is greater than the spacing between adjacent LED beads in the third zone; The spacing between adjacent LED beads in the first zone is smaller than the spacing between adjacent LED beads in the third zone.

9. The display module according to claim 8, characterized in that, The backlight module also includes a light guide strip, a diffuser plate, and a diffuser sheet; The light guide strip, the diffuser plate, and the diffuser sheet are located within the space formed by the back plate and the middle frame, and are stacked sequentially away from the LED beads; The light guide strips are distributed around the four edges of the display panel; The middle frame includes a boss located between the support surface and the inverted U-shaped opening; The light guide strip is located on the protrusion and is fixedly connected to the protrusion; The diffuser includes at least two sub-diffusers, which are stacked sequentially on the side of the diffuser plate away from the lamp bead. The diffuser plate is spaced apart from the lamp beads.

10. The display module according to claim 6, characterized in that, It also includes a first fastening tape and a second fastening tape; The second fastening tape is attached to the side of the protective cover away from the side wall, and the upper edge of the second fastening tape is flush with the display side surface of the display panel. The first fastening tape is attached to the side of the second fastening tape opposite to the protective cover, and the first fastening tape also extends to cover the display side frame of the display panel. The first fastening tape is also attached to the outer side of the middle frame on the non-bonding side of the display panel, and the upper edge of the first fastening tape on this side is flush with the display side surface of the display panel.

11. A splicing display screen, characterized in that, It includes at least two display modules as described in any one of claims 1-10, wherein the at least two display modules are spliced ​​together; The display module includes a bonded side edge and an unbonded side edge, and the flexible bonded circuit board in the display module is disposed on the bonded side edge; The bound side edge of the display module is spliced ​​with the unbound side edge.

12. The splicing display screen according to claim 11, characterized in that, The seam width of the display panel in the display module ranges from 1.2 to 2.0 mm.

13. The splicing display screen according to claim 12, characterized in that, The seam width of the display module ranges from 1.8 to 2.6 mm.

14. A method for manufacturing a display module as described in any one of claims 1-10, comprising: The backlight module and display panel are fabricated separately. Apply adhesive to the support surface of the middle frame in the backlight module; The display panel is placed on the support surface to achieve bonding between the backlight module and the display panel; The adhesive is characterized in that it is applied by spraying through a spray valve, and the temperature range of the spray valve during spraying is 100℃~120℃; The frequency range of the valve striker is 900–1000 Hz; The adhesive application speed range for the bonding edge of the display module is 140–150 mm / s; The adhesive application speed range for the non-bonded edge of the display module is 90–100 mm / s; Before the display panel is bonded to the backlight module, the initial curing energy range of the adhesive is 1000–1100 mJ / cm². 2 ; After the display panel is bonded to the backlight module, the pressure holding weight of the adhesive is 0 kg.

Images