LED display module and packaging process thereof

Abstract

The application provides an LED display module and a packaging process thereof. The LED display module comprises a lamp panel, the lamp panel comprising a substrate and a light emitter, the front surface of the substrate being provided with a solder pad, and the light emitter being connected to the solder pad; a composite film, the composite film comprising a peelable film and an optical film, the peelable film being filled between adjacent light emitters and covering the front surface of the substrate and the front surface of the light emitter; the optical film being attached to the peelable film; an adhesive film, the adhesive film being attached between the front surface of the substrate and the peelable film to enhance the adhesion between the peelable film and the substrate; and the height of the adhesive film being lower than the height of the solder pad. The packaging process of the LED display module comprises hot pressing the peelable film, and the peelable film is hot-filled between adjacent light emitters and covers the front surface of the substrate and the front surface of the light emitter. The LED display module in the application can be easily peeled off while ensuring strong adhesion between the peelable film and the substrate, and will not affect the light emitter.

Description

Technical Field

[0001] This application belongs to the field of packaging technology, and more specifically, relates to an LED display module and its packaging process. Background Technology

[0002] With the development of LED display technology, pixel pitch has gradually decreased, and the size of light-emitting elements (such as SMD surface mount LEDs, COB chips, and MIP LEDs) has also become smaller. The solder joints between the light-emitting elements and the substrate have also become smaller. The reduction in solder joints weakens the light-emitting elements' resistance to thrust, making them more susceptible to desoldering and LED detachment during handling. Currently, the industry generally uses surface encapsulation to improve the protection of LED display modules. Examples include AOB (Admixture on Board) or GOB (Glue on Board) technologies based on SMD surface mount LEDs, and COB (Chip on Board) technology. AOB technology reinforces the solder joints with a thin layer of epoxy resin, then coats the surface with a protective layer to achieve hybrid encapsulation. GOB and COB technologies use potting compound to completely encapsulate the surface of the LED board, forming a smooth potting surface. The most commonly used potting compounds are epoxy resin and silicone. Epoxy resin has high internal stress during curing, which can easily squeeze the light source and solder joints, causing dead LEDs. During repair, the damaged epoxy resin needs to be removed. Similarly, when repairing silicone, the damaged silicone needs to be removed, which is more difficult. Summary of the Invention

[0003] The purpose of this application is to provide an LED display module and its packaging process to solve the technical problem of high difficulty in reworking LED display modules in the prior art.

[0004] To achieve the above objectives, the technical solution adopted in this application is: to provide an LED display module, comprising:

[0005] A light board, comprising a substrate and a light-emitting element, wherein pads are distributed on the front side of the substrate and the light-emitting element is connected to the pads;

[0006] A composite film comprising a peelable film and an optical film, wherein the peelable film is filled between adjacent light emitters and covers the front side of the substrate and the front side of the light emitters; the optical film is adhered to the peelable film;

[0007] An adhesive film is attached between the front side of the substrate and the peelable film to enhance the adhesion between the peelable film and the substrate; the height of the adhesive film is lower than the height of the pads.

[0008] In one possible design, the adhesive film is a first adhesive film adhered to the perimeter of the front side of the substrate.

[0009] In one possible design, the width of the first adhesive film is less than half the distance between adjacent light-emitting elements.

[0010] In one possible design, the material of the first adhesive film is epoxy resin, silicone, or acrylic adhesive.

[0011] In one possible design, the adhesive film is a second adhesive film adhered to the periphery of the front side of the substrate and located between adjacent light emitters on the front side of the substrate; the second adhesive film can be peeled off along with the peelable film.

[0012] In one possible design, the second adhesive film is a transparent UV adhesive;

[0013] And / or, the adhesion of the second adhesive film to the substrate decreases when the temperature is higher than a preset temperature after curing.

[0014] In one possible design, an anti-sticking layer is formed on the top and / or bottom and / or side surfaces of the light-emitting body.

[0015] In one possible design, the material of the anti-stick layer is polytetrafluoroethylene, silicon dioxide, or ceramic material;

[0016] And / or, the thickness of the anti-adhesive layer is 1 nm to 1000 nm.

[0017] In one possible design, the adhesive film is also formed at the location where the light-emitting body has the anti-adhesive layer.

[0018] In one possible design, the peelable membrane is made of one or more of polycarbonate, polyacrylate, polyurethane, vinyl acetate copolymer, polyamide, polyolefin, and rubber.

[0019] In one possible design, the softening temperature of the peelable membrane is 80°C to 180°C.

[0020] In one possible design, there is a gap between the bottom of the light-emitting element and the substrate, which can be filled by hot pressing of the peelable film.

[0021] In one possible design, the peelable film further includes side edging formed on a circumferential side of the substrate.

[0022] In one possible design, the peelable film also includes a bottom edging formed around the back edge of the substrate.

[0023] In one possible design, the width of the side edging and the height of the bottom edging are not greater than 50 μm, and the width of the bottom edging is not greater than 1000 mm.

[0024] In one possible design, the optical film is made of polyethylene terephthalate;

[0025] And / or, the softening temperature of the optical film is higher than the softening temperature of the peelable film;

[0026] And / or, the surface of the optical film is formed with an optical structure;

[0027] And / or, the optical film is adhered to the peelable film by optical adhesive.

[0028] The beneficial effects of the LED display module provided in this application are as follows: The LED display module provided in this application, by encapsulating a peelable film and an optical film on the lamp board, allows the peelable film to fill the gaps between the light emitters and cover the entire lamp board after hot pressing. The optical film can optically process the light emitted by the light emitters. Furthermore, when the lamp board needs maintenance, the peelable film can be easily peeled off, greatly reducing the difficulty of maintenance. Simultaneously, an adhesive film is provided between the front side of the substrate and the peelable film, and the height of the adhesive film is lower than the height of the pads. This enhances the adhesion between the peelable film and the substrate while preventing the peelable film from exerting a pushing force on the pads and light emitters during peeling.

[0029] On the other hand, this application also provides a packaging process for an LED display module, including the following steps:

[0030] S10: Fabricate a lamp board, the lamp board including a substrate and a light-emitting element, the front side of the substrate is provided with pads, and the light-emitting element is connected to the pads;

[0031] S30: An adhesive film is formed on the front side of the substrate, and the height of the adhesive film is lower than the height of the pad;

[0032] S50: A peelable film is pasted onto the adhesive film, the substrate, and the light-emitting body; the peelable film is hot-pressed; the peelable film is heated and filled between adjacent light-emitting bodies and covers the front side of the substrate and the front side of the light-emitting body.

[0033] S70: An optical film is attached to the peelable film;

[0034] Step S50 can be performed before or after step S70.

[0035] The beneficial effects of the LED display module packaging process provided in this application are as follows: The LED display module packaging process provided in this application uses hot pressing to encapsulate a peelable film on the lamp board. After hot pressing, the peelable film can fill the gaps between the light emitters and cover the entire lamp board, ensuring the protective function of the peelable film for the lamp board. Moreover, when the lamp board needs to be repaired, the peelable film can be easily peeled off from the lamp board, greatly reducing the difficulty of repair. At the same time, an adhesive film is provided between the front side of the substrate and the peelable film, and the height of the adhesive film is lower than the height of the pads. This enhances the adhesion between the peelable film and the substrate while preventing the peelable film from exerting a pushing force on the pads and light emitters during peeling. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the structure of the lamp board of the LED display module provided in the embodiments of this application;

[0038] Figure 2 This is a schematic diagram of the structure of the composite film of the LED display module provided in the embodiments of this application;

[0039] Figure 3 This is a schematic diagram of the structure of the LED display module provided in the embodiments of this application;

[0040] Figure 4 This is a schematic diagram of the structure of the LED display module provided in Embodiment 1 of this application;

[0041] Figure 5 for Figure 4 A top view of the substrate, pads, and first adhesive film;

[0042] Figure 6 This is a schematic diagram of the structure of the LED display module provided in Embodiment 2 of this application;

[0043] Figure 7 This is a schematic diagram of the structure of the LED display module provided in Embodiment 3 of this application;

[0044] Figure 8 This is a schematic diagram of the structure of the LED display module provided in Embodiment Six of this application;

[0045] Figure 9 This is a schematic diagram of the LED display module package provided in Embodiment Six of this application;

[0046] Figure 10 This is a schematic diagram of the structure of the LED display module provided in Embodiment 7 of this application;

[0047] Figure 11 This is a schematic diagram of the packaging of the LED display module provided in Embodiment 7 of this application.

[0048] The following are the labeling elements in the figure:

[0049] 1. Lamp board; 11. Substrate; 12. Light emitter; 13. Solder pad; 14. Driver IC; 15. Bottom gap; 2. Peelable film; 21. Bottom filler; 22. Side edging; 23. Bottom edging; 3. Optical film; 4. Adhesive film; 4a. First adhesive film; 4b. Second adhesive film; 5. Anti-stick layer; 200. Mold; 210. Mold cavity; 211. Side gap; 212. Bottom gap; 300. Piston. Detailed Implementation

[0050] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0051] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0052] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0054] Please see Figures 1 to 4The LED display module provided in the embodiments of this application will now be described.

[0055] The LED display module includes a lamp board 1, a composite film, and an adhesive film 4. The lamp board 1 includes a substrate 11 and a light emitter 12. Pads 13 are distributed on the front side of the substrate 11, and the light emitter 12 is connected to the pads 13. The composite film includes a peelable film 2 and an optical film 3. The peelable film 2 fills the space between adjacent light emitters 12 and covers the front side of the substrate 11 and the front side of the light emitter 12. The optical film 3 is adhered to the peelable film 2. The adhesive film 4 is adhered between the front side of the substrate 11 and the peelable film 2 to enhance the adhesion between the peelable film 2 and the substrate 11. The height of the adhesive film 4 is lower than the height of the pads 13.

[0056] The light-emitting element 12 is an LED point light source used for emitting light. The light-emitting element 12 can be an SMD surface-mount LED, a COB chip, or a MIP LED. The light-emitting elements 12 are distributed on the substrate 11 according to a certain rule, for example, the light-emitting elements 12 are distributed in a matrix on the substrate 11. A driver IC 14 is also provided on the side of the substrate 11 opposite to the light-emitting elements 12. The driver IC 14 is used to drive the light-emitting elements 12.

[0057] The peelable film 2 is formed by hot-pressing peelable adhesive onto the lamp panel 1. The peelable film 2 possesses strong water resistance, oil resistance, corrosion resistance, and insulation properties, thus providing protection for the lamp panel 1. Specifically, the peelable film 2 exhibits fluidity during hot pressing, allowing it to flow and fill between adjacent light-emitting elements 12 to protect them. Furthermore, the peelable film 2 softens at a preset temperature, enabling easy peeling from the front side of the substrate 11, the front side of the light-emitting elements 12, and between adjacent light-emitting elements 12, reducing the difficulty of maintaining the lamp panel 1.

[0058] The optical film 3 can perform optical processing on the light emitted by the light source 12, such as diffusing the light and increasing the light transmittance. Specifically, an optical structure, such as a microscopic optical structure and surface structure, can be formed on the surface of the optical film 3 away from the peelable film 2, thereby achieving the diffusing of light and increasing the light transmittance. In addition, it also meets physical requirements such as fingerprint resistance and scratch resistance.

[0059] The adhesive film 4 can be applied to the front side of the substrate 11, except for the light-emitting body 12, to enhance the adhesion between the peelable film 2 and the substrate 11; the adhesive film 4 can also be applied only to a local area on the front side of the substrate 11, as long as it can enhance the adhesion between the peelable film 2 and the substrate 11.

[0060] When maintenance is required, first soften the peelable film 2, and then peel off the peelable film 2 and the optical film 3 together; when the adhesive film 4 is pasted between the light emitters 12, the adhesive film 4 can be set to be peeled off together with the peelable film 2; when the adhesive film 4 is pasted on the periphery of the substrate 11, the adhesive film 4 can be set to be non-peelable or can be peeled off together with the peelable film 2.

[0061] Furthermore, since the adhesive film 4 is formed on the front side of the substrate 11 and the pad 13 is also formed on the front side of the substrate 11, when the height of the adhesive film 4 is lower than the height of the pad 13, the top side of the adhesive film 4 is also lower than the top side of the pad 13. That is, the peelable film 2 extends below the top side of the pad 13, so that when the peelable film 2 is peeled off, the pad 13 will not be peeled off along with the peelable film 2.

[0062] In one embodiment, the peelable film 2 is made of one or more of polycarbonate, polyacrylate, polyurethane, vinyl acetate copolymer, polyamide, polyolefin, and rubber. In actual manufacturing, the desired composition of the peelable film 2 can be obtained through repeated experiments based on the adhesion requirements between the peelable film 2 and the substrate 11, as well as the peeling conditions of the peelable film 2.

[0063] In one embodiment, the softening temperature of the peelable film 2 is 80°C to 180°C, for example, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, or 180°C. When the peelable film 2 is within its softening temperature range, it will soften and can be easily peeled off from the substrate 11 and the light emitter 12.

[0064] Optionally, the material of the optical film 3 is polyethylene terephthalate (PET). PET has good mechanical properties, good waterproof performance, high transparency, can block ultraviolet rays, and has good gloss. Therefore, it can be used in LED display modules to achieve light processing and at the same time protect the lamp board 1.

[0065] Optionally, if the softening temperature of the optical film 3 is higher than that of the peelable film 2, the optical film 3 will not be softened when the peelable film 2 is peeled off, and the optical film 3 can be peeled off together with the peelable film 2, thereby improving the peeling efficiency.

[0066] During the molding process, the optical film 3 can first be adhered to the peelable film 2 using optical adhesive, then the composite film of the peelable film 2 and the optical film 3 can be adhered to the lamp panel 1, and finally the peelable film 2 can be hot-pressed onto the lamp panel 1. Alternatively, the peelable film 2 can be hot-pressed onto the lamp panel 1 first, and then the optical film 3 can be adhered to the peelable film 2 using optical adhesive.

[0067] Optionally, the optical film 3 is adhered to the peelable film 2 using optical adhesive, the thickness of which is no more than 50 μm. The optical adhesive is used to adhere the optical film 3 to the peelable film 2. If the optical adhesive is too thick, it will affect the light emission performance of the LED display module. Therefore, the thickness of the optical adhesive needs to be limited to 50 μm or less. For example, the thickness of the optical adhesive can be 50 μm, 46 μm, 42 μm, 38 μm, and 34 μm, etc.

[0068] Example 1:

[0069] Please see Figure 4 and Figure 5 The adhesive film 4 is a first adhesive film 4a that is pasted on the periphery of the front side of the substrate 11. That is, the first adhesive film 4a is only set on the periphery of the front side of the substrate 11. This setting can not only increase the adhesion between the peelable film 2 and the substrate 11, but also ensure that the first adhesive film 4a will not hinder the peeling of the peelable film 2 when it is peeled off. Even after the peelable film 2 is peeled off, the first adhesive film 4a can still be pasted on the substrate 11 without hindering the maintenance of the substrate 11.

[0070] Optionally, the material of the first adhesive film 4a can be epoxy resin, silicone, or acrylic adhesive. Since the first adhesive film 4a is formed around the edge of the front side of the substrate 11, it will not affect the light emitter 12 or the peelable film 2. Therefore, the first adhesive film 4a only needs to have sufficiently strong adhesion; epoxy resin, silicone, or acrylic adhesives are all materials with strong adhesion. Furthermore, when the first adhesive film 4a is made of a high-strength epoxy resin, it will not peel off when the peelable film 2 is removed. When the first adhesive film 4a is made of an acrylic adhesive, its adhesion is generally weak, and in this case, the first adhesive film 4a can be peeled off together with the peelable film 2.

[0071] Optionally, the first adhesive film 4a can be formed on the periphery of the front side of the substrate 11 by dispensing adhesive.

[0072] Please see Figure 5The first adhesive film 4a can be formed at any position between the outer edge of the substrate 11 and the outermost light-emitting element 12. Preferably, the outer edge of the first adhesive film 4a is flush with the outer edge of the substrate 11. This arrangement can prevent the edge of the peelable film 2 from lifting and avoid the peelable film 2 from falling off during use.

[0073] In one embodiment, see Figure 5 The width of the first adhesive film 4a is less than half the distance between adjacent light-emitting elements 12. Specifically, the distance between the light-emitting elements 12 here refers to... Figure 5 The spacing between adjacent light-emitting elements 12 in the left-right direction, and the two pads 13 on the same light-emitting element 12 are distributed in the left-right direction. For example, when two lamp boards 1 are spliced, the distance from the outermost light-emitting element 12 of each lamp board 1 to the outer edge of the substrate 11 is 1 / 2 the spacing between the light-emitting elements 12. Therefore, when the width of the first adhesive film 4a is set to be less than 1 / 2 the spacing between the light-emitting elements 12, the first adhesive film 4a can be prevented from being pasted onto the light-emitting elements 12. In this embodiment, by limiting the width of the first adhesive film 4a, the first adhesive film 4a will not affect the peeling of the peelable film 2 between adjacent light-emitting elements 12 when the peelable film 2 is peeled off, that is, it will not exert a pulling force on the light-emitting elements 12.

[0074] Example 2:

[0075] All the technical features of the LED display module in this embodiment are basically the same as those of the LED display module in Embodiment 1. The difference is: Please refer to Figure 6 The adhesive film 4 is a second adhesive film 4b adhered to the periphery of the front surface of the substrate 11 and between adjacent light-emitting elements 12 on the front surface of the substrate 11. Specifically, the second adhesive film 4b is formed not only around the periphery of the front surface of the substrate 11, but also on the front surface of the substrate 11 between adjacent light-emitting elements 12. This arrangement results in high adhesion strength and uniform adhesion strength distribution between the peelable film 2 and the substrate 11. Furthermore, the second adhesive film 4b can be peeled off along with the peelable film 2. Since the second adhesive film 4b is adhered to the substrate 11 between adjacent light-emitting elements 12, it needs to be peeled off during maintenance to facilitate repair.

[0076] In one embodiment, after the second adhesive film 4b is cured, its adhesion to the substrate 11 decreases when the temperature is higher than a preset temperature. When the peelable film 2 is peeled off, the second adhesive film 4b can be peeled off together. The preset temperature can be 95°C, 100°C, 105°C, 110°C, 115°C, and 120°C, etc., mainly limited according to the material of the second adhesive film 4b.

[0077] Optionally, the material of the second adhesive film 4b can be transparent UV adhesive. UV adhesive (shadowless adhesive), also known as photosensitive adhesive or ultraviolet curing adhesive, is a type of adhesive that must be cured by ultraviolet light irradiation and can be used as an adhesive.

[0078] In this embodiment, the second adhesive film 4b needs to be peeled off together with the peelable film 2 because the second adhesive film 4b needs to be made of a material with strong adhesion and adhesion that can change with temperature.

[0079] Example 3:

[0080] All the technical features of the LED display module in this embodiment are basically the same as those of the LED display module in Embodiment 1. The difference is: Please refer to Figure 7 An anti-stick layer 5 is formed on the top and / or bottom and / or side surfaces of the light-emitting body 12. Specifically, before forming the peelable film 2, an anti-stick layer 5 is first formed on the top, bottom, and side surfaces of the light-emitting body 12, and then the peelable film 2 is formed on the anti-stick layer 5. The anti-stick layer 5 has an anti-stick effect, which can reduce the adhesion of the peelable film 2 to the light-emitting body 12 and avoid dead light when peeling off the peelable film 2. It is understood that in some other embodiments, the anti-stick layer 5 may only be formed on the top, bottom, or side surfaces of the light-emitting body 12, or the anti-stick layer 5 may be formed on the top and side surfaces, the bottom and side surfaces, or the top and bottom surfaces; this is not a unique limitation.

[0081] Alternatively, the material of the anti-stick layer 5 can be polytetrafluoroethylene, silicon dioxide, or ceramic material.

[0082] Optionally, the thickness of the anti-adhesive layer 5 is 1nm to 1000nm. For example, the thickness of the anti-adhesive layer 5 is 1nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, and 1000nm. The thickness of the anti-adhesive layer 5 cannot be too thin, as this will affect the anti-adhesive effect and increase the difficulty of molding. The thickness of the anti-adhesive layer 5 also cannot be too thick, as this will affect the thickness of the peelable film 2 and waste material costs.

[0083] The anti-stick layer 5 can be formed on the light-emitting body 12 by coating or spraying, so that the anti-stick layer 5 is thin enough and uniformly formed.

[0084] Example 4:

[0085] In this embodiment, all the technical features of the LED display module are basically the same as those of the LED display module in Embodiment 3. The difference is that the adhesive film 4 is also formed at the position where the anti-adhesive layer 5 is formed on the light-emitting body 12. For example, when the anti-adhesive layer 5 is formed on the top surface of the light-emitting body 12, the adhesive film 4 can be formed on the top surface of the light-emitting body 12. This arrangement not only enhances the adhesion between the peelable film 2 and the light-emitting body 12 through the adhesive film 4, but also reduces the adhesion between the peelable film 2 and the light-emitting body 12 when peeling off the peelable film 2, thereby making the peelable film 2 easy to peel off. In addition, the anti-adhesive layer 5 can also be formed on the side of the light-emitting body 12, and the adhesive film 4 can be formed on the anti-adhesive layer 5. This is not the only limitation.

[0086] Example 5:

[0087] All the technical features of the LED display module in this embodiment are basically the same as those of the LED display module in Embodiment 1. The difference is: Please refer to Figure 3 There is a gap 15 between the bottom of the light-emitting body 12 and the substrate 11. The peelable film 2 can fill the gap 15 during hot pressing. Specifically, two pads 13 are formed on the substrate 11 corresponding to each light-emitting body 12. The light-emitting body 12 is disposed on the two pads 13. The light-emitting body 12, the two pads 13 and the substrate 11 surround to form the gap 15. When the peelable film 2 is formed on the lamp board 1 by hot pressing, the peelable film 2 can be squeezed into the gap 15 and fill the gap 15 during the hot pressing process. For ease of description, this part of the peelable film 2 that fills the gap 15 is called the bottom filler 21. The formation of the bottom filler 21 has a good supporting effect on the light-emitting body 12. In addition, during maintenance, the softened bottom filler 21 can be cut by the light-emitting body 12 to achieve complete peeling.

[0088] In summary, the peelable film 2, under vacuum and softening temperature conditions, forms an LED display module with the lamp board 1 via molding or lamination equipment. The peelable film 2 undergoes a physical change during cooling and curing, resulting in uniform temperature and minimal volume change, thus minimizing stress and improving product yield. The peelable film 2 can be completely peeled off the lamp board 1 after softening by heating, facilitating repairs to the lamp board 1. After softening, the underfill 21 can be cut by the light-emitting element 12 without detaching the light-emitting element 12 from the pad 13.

[0089] Example 6:

[0090] All the technical features of the LED display module in this embodiment are basically the same as those of the LED display module in Embodiment 1. The difference is: Please refer to Figure 8 and Figure 9The peelable film 2 also includes a side edge 22, which is formed on a circumferential side of the substrate 11. Specifically, a mold cavity 210 is formed in the hot pressing mold 200, and the lamp plate 1 is placed in the mold cavity 210, such that there is a side gap 211 between the circumferential side wall of the substrate 11 and the side wall of the mold cavity 210. When the peelable film 2 is hot-pressed, the circumferential edge of the peelable film 2 can be squeezed into the side gap 211 to form the side edge 22. By covering the circumferential side of the substrate 11 with the side edge 22, the adhesion and sealing between the peelable film 2 and the substrate 11 can be effectively improved, and problems such as edge curling caused by collision and friction during transportation and use can be avoided.

[0091] The width of the side edge 22 is no greater than 50μm, for example, the width of the side edge 22 is 35μm, 38μm, 41μm, 44μm, 47μm and 50μm. By limiting the size of the side edge 22, the width of the side edge 22 is small enough to meet the pixel pitch requirements of the LED display module, while improving the adhesion and sealing between the peelable film 2 and the substrate 11.

[0092] In addition, please see Figure 9 Furthermore, multiple pistons 300 can be provided on the mold cavity 210, with each piston 300 corresponding to a circumference of the substrate 11. When installing the substrate 11, the substrate 11 can be positioned by each piston 300 abutting against a circumference of the substrate 11. After positioning, the aforementioned side gap 211 can be formed between each piston 300 and a circumference of the substrate 11.

[0093] Example 7:

[0094] All the technical features of the LED display module in this embodiment are basically the same as those of the LED display module in Embodiment Six. The difference is: Please refer to Figure 10 and Figure 11 The peelable film 2 also includes a bottom edge 23 formed on the periphery of the back side of the substrate 11. Specifically, a mold cavity 210 is formed in the hot pressing mold 200, and the lamp plate 1 is placed in the mold cavity 210. By providing side gaps 211 on the periphery of the substrate 11 and bottom gaps 212 on the periphery of the back side of the substrate 11, the periphery of the peelable film 2 can be squeezed to the side gaps 211 and bottom gaps 212 to form side edges 22 and bottom edges 23 during hot pressing of the peelable film 2. By covering the periphery of the side and back sides of the substrate 11 with the side edges 22 and bottom edges 23, the adhesion and sealing between the peelable film 2 and the substrate 11 can be effectively improved, and problems such as edge curling caused by collision and friction during transportation and use can be avoided.

[0095] The width of the side edge 22 and the height of the bottom edge 23 are not greater than 50μm. For example, the width of the side edge 22 is 35μm, 38μm, 41μm, 44μm, 47μm, and 50μm. The width of the bottom edge 23 is not greater than 1000mm. For example, the width of the bottom edge is 1000mm, 900mm, 800mm, 700mm, 600mm, 500mm, 400mm, 300mm, 200mm, or 100mm, with 500mm, 400mm, 300mm, 200mm, or 100mm being preferred. This embodiment limits the size of the side edge 22, ensuring that while improving the adhesion and sealing between the peelable film 2 and the substrate 11, the width of the side edge 22 is sufficiently small to meet the pixel pitch requirements of the LED display module.

[0096] On the other hand, this application also provides a packaging process for an LED display module, characterized by including the following steps:

[0097] S10: Fabricate lamp board 1. Lamp board 1 includes substrate 11 and light source 12. Pads 13 are distributed on the front side of substrate 11. Light source 12 is connected to pads 11.

[0098] S30: An adhesive film 4 is formed on the front side of the substrate 11, and the height of the adhesive film 4 is lower than the height of the pad 13.

[0099] S50: A peelable film 2 is pasted onto the adhesive film 4, the substrate 11 and the light-emitting body 12. The peelable film 2 is hot-pressed and the peelable film 2 is heated and filled between adjacent light-emitting bodies 12 and covers the front side of the substrate 11 and the front side of the light-emitting body 12.

[0100] S70: Attach the optical film 3 onto the peelable film 2;

[0101] Step S50 can be performed before or after step S70.

[0102] In this embodiment, a peelable film 2 is encapsulated on the lamp board 1 by hot pressing, so that after hot pressing, the peelable film 2 can fill the gap between the light-emitting elements 12 and cover the entire lamp board 1, thus ensuring the protective effect of the peelable film 2 on the lamp board 1.

[0103] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An LED display module, characterized in that, include: A light board, comprising a substrate and a light-emitting element, wherein pads are distributed on the front side of the substrate and the light-emitting element is connected to the pads; A composite film comprising a peelable film and an optical film, wherein the peelable film is filled between adjacent light emitters and covers the front side of the substrate and the front side of the light emitters; the optical film is adhered to the peelable film, wherein the softening temperature of the optical film is higher than that of the peelable film; An adhesive film is attached between the front side of the substrate and the peelable film to enhance the adhesion between the peelable film and the substrate; the height of the adhesive film is lower than the height of the pads. An anti-sticking layer is formed on the top and / or bottom and / or side surfaces of the light-emitting body; The adhesive film is a first adhesive film that is pasted on the front edge of the substrate.

2. The LED display module as described in claim 1, characterized in that, The width of the first adhesive film is less than half the distance between adjacent light-emitting elements; And / or, the material of the first adhesive film is epoxy resin, silicone or acrylic adhesive.

3. The LED display module as described in claim 1, characterized in that, The adhesive film is a second adhesive film that is adhered to the perimeter of the front side of the substrate and located between adjacent light-emitting elements on the front side of the substrate; the second adhesive film can be peeled off together with the peelable film.

4. The LED display module as described in claim 3, characterized in that, The second adhesive film is a transparent UV adhesive; And / or, the adhesion of the second adhesive film to the substrate decreases when the temperature is higher than a preset temperature after curing.

5. The LED display module as described in any one of claims 1 to 4, characterized in that, The anti-adhesive layer is made of polytetrafluoroethylene, silicon dioxide, or ceramic materials. And / or, the thickness of the anti-adhesive layer is 1 nm to 1000 nm.

6. The LED display module as described in any one of claims 1 to 4, characterized in that, The peelable membrane is made of one or more of the following: polycarbonate, polyacrylate, polyurethane, vinyl acetate copolymer, polyamide, polyolefin, and rubber. And / or, the softening temperature of the peelable membrane is 80°C to 180°C.

7. The LED display module as described in any one of claims 1 to 4, characterized in that, There is a gap between the bottom of the light-emitting body and the substrate, and the peelable film can fill the gap when hot-pressed.

8. The LED display module as described in any one of claims 1 to 4, characterized in that, The peelable film also includes a side edging formed on one side of the substrate; Alternatively, the peelable film may further include a side edge formed on one side of the substrate and a bottom edge formed on one side of the back of the substrate.

9. A packaging process for an LED display module, characterized in that, For encapsulating the LED display module as described in claim 1, the following steps are included: S10: Fabricate a lamp board, the lamp board including a substrate and a light-emitting element, the front side of the substrate is provided with pads, and the light-emitting element is connected to the pads; S30: An adhesive film is formed on the front side of the substrate, and the height of the adhesive film is lower than the height of the pad; S50: A peelable film is pasted onto the adhesive film, the substrate, and the light-emitting body; the peelable film is hot-pressed; the peelable film is heated and filled between adjacent light-emitting bodies and covers the front side of the substrate and the front side of the light-emitting body. S70: An optical film is attached to the peelable film; Step S50 can be performed before or after step S70.

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