Display module glue filling method and display module repair method

Abstract

This invention discloses a method for applying adhesive to a display module. The display module's LED beads are encapsulated with a first encapsulation body, which has a notch. The method includes: filling the notch with encapsulation adhesive; curing the encapsulation adhesive to form a second encapsulation body, wherein the lowest point of the upper surface of the second encapsulation body is lower than the surface of the first encapsulation body, and the highest point of the upper surface of the second encapsulation body is lower than or equal to the surface of the first encapsulation body; and affixing a protective film to the surfaces of the first and second encapsulation bodies. The protective film includes an elastic adhesive layer and a light-transmitting layer, with the elastic adhesive layer serving as the bottom layer of the protective film. Compared with existing technologies, this invention has a simple process and low cost. This invention also discloses a method for reworking a display module.

Description

Technical Field

[0001] This invention relates to a repair method for display modules, and more particularly to a repair adhesive for display modules. Background Technology

[0002] An LED display screen typically consists of a light board, several LED chips on the light board, a transparent encapsulation layer that encapsulates the LED chips, a black layer applied to the encapsulation layer, and a transparent protective layer formed on the black layer. When an LED display screen leaves the factory, the LED chips on the light board encapsulated with transparent encapsulant are first tested to ensure they meet standards, including whether they are too dim or misaligned. If any issues are found, the LED display screen needs to be repaired.

[0003] Referring to Chinese patent CN115224165A, a method for packaging and repairing miniLEDs is disclosed. During repair, the location of the defective pixel on the display board is first tested, then the original encapsulation adhesive is broken and the LED chip at the defective pixel location is removed. After removal, a new chip is placed in, soldered, and installed. After installation, encapsulation adhesive is applied again. Although ideally, the glue should be flush with the surface of the original encapsulation adhesive, if the glue is slightly lower than the original encapsulation layer, the molding machine may not be able to contact the glue surface during hot pressing, making it impossible to mold the glue after glue application. Therefore, to ensure that the glue can be molded normally, glue is generally injected at the glue application point that is higher than the surface of the original encapsulation adhesive. After molding, the newly applied encapsulation adhesive often cures slightly higher than the original encapsulation layer on the display board. Therefore, it is necessary to grind the surface of the newly applied encapsulation adhesive resin to make it flush with the original encapsulation layer to complete the repair of the display screen. Finally, a black layer and a transparent protective layer are sprayed on the encapsulation layer. After the above-mentioned miniLED is disassembled and repaired, the repaired encapsulation layer must be polished to make the new encapsulation layer flush with the original encapsulation layer. Not only is the process complicated and it is difficult to avoid leaving obvious polishing marks, but also, due to insufficient polishing precision, the newly repaired area will often have a certain protrusion, which will change the optical effect of the display screen and affect the performance of the display screen.

[0004] To address this, patent CN112951972A discloses a COB module repair method. During adhesive replenishment, a capillary needle is used to apply adhesive to the previously damaged surface gap. The amount is first applied until saturated, then reduced by a predetermined amount. While this reduces the amount of adhesive needed, to ensure the molding machine fully contacts the adhesive during curing, the final adhesive level must reach the height of the original encapsulation surface. Since the cured adhesive will slightly protrude in the middle, the newly cured encapsulated body will inevitably have a slightly convex center, altering the optical effect of the display screen and affecting its performance.

[0005] Therefore, there is an urgent need for a method to re-apply adhesive to display modules that can solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a method for applying adhesive to a display module and a method for repairing a display module. After the adhesive is cured, the upper surface of the package after application is lower than the upper surface of the original package, eliminating the need to grind a new package. Furthermore, an elastic adhesive layer is used to slightly fill the depression formed by the new package, and the surface of the repaired display module is made flush by the strength support of the light-transmitting layer. The process is simple and the cost is low.

[0007] To achieve the above objectives, the present invention discloses a method for applying adhesive to a display module. The display module has a first encapsulation body encapsulated on its LED beads, and the first encapsulation body has a notch. The method includes: filling the notch with encapsulation adhesive; curing the encapsulation adhesive to form a second encapsulation body, wherein the lowest point of the upper surface of the second encapsulation body is lower than the surface of the first encapsulation body, and the highest point of the upper surface of the second encapsulation body is lower than or equal to the surface of the first encapsulation body; and affixing a protective film to the surfaces of the first and second encapsulation bodies. The protective film includes an elastic adhesive layer and a light-transmitting layer, wherein the elastic adhesive layer is the bottom layer of the protective film.

[0008] Compared with the prior art, the present invention, after curing the supplementary encapsulating adhesive, makes the upper surface of the second encapsulation body lower than the upper surface of the original encapsulation body, eliminating the need to grind the new encapsulation body. Furthermore, the elastic adhesive layer slightly fills the depression formed by the new encapsulation body, and the strength of the light-transmitting layer supports the depression formed by the second encapsulation body, making the surface of the repaired display module flush. The process is simple and the cost is low.

[0009] Preferably, in step two, a hot press block is used to at least partially extend into the notch to hot press the encapsulating adhesive within the notch, thereby molding the encapsulating adhesive to form a second encapsulation.

[0010] More preferably, when filling the notch with encapsulating adhesive, the amount of encapsulating adhesive is less than the volume of the notch, so that there is a first difference Δh between the upper surface of the filled encapsulating adhesive and the upper edge of the notch, the first difference Δh being less than or equal to the depth h0 of the hot press block extending into the notch and greater than 0.

[0011] More preferably, the depth h0 ranges from 0 to 30 μm.

[0012] More preferably, when the notch is filled with encapsulating adhesive, the distance from the upper surface of the encapsulating adhesive to the upper surface of the LED bead is h1, where h0 < (h1 + Δh).

[0013] More preferably, the end dimension of the hot press block is smaller than the dimension of the notch, so that an overflow area is formed between the hot press block and the notch.

[0014] More preferably, the end of the hot press block gradually tapers so that the end of the hot press block is truncate.

[0015] More preferably, after the hot pressing block extends into the notch, the position where the hot pressing block is flush with the upper edge of the notch has a first dimension, and the notch entrance has a second dimension, wherein the difference between the second dimension and the first dimension is less than or equal to a preset value and greater than or equal to 0.

[0016] More preferably, the end of the hot pressing block forms a horizontal hot pressing surface; or the end of the hot pressing block includes a plurality of densely distributed serrated grooves, so that after the hot pressing block heat-presses the encapsulating adhesive, the surface of the second encapsulation body is serrated; or the end of the hot pressing block includes a horizontal hot pressing surface, and the hot pressing surface is recessed with a plurality of overflow recesses, so that after the hot pressing block heat-presses the encapsulating adhesive, the surface of the second encapsulation body is convex with a plurality of protrusions.

[0017] More preferably, before step two, the method further includes the step of: setting an isolation layer around the notch; and between step two and step three, the method further includes the step of: removing the isolation layer and tearing off the excess encapsulating adhesive that has been hot-pressed to the outside of the notch by the hot press block.

[0018] Preferably, the elastic adhesive layer comprises a pressure-sensitive adhesive layer. The light-transmitting layer comprises a polyester film layer.

[0019] Preferably, the light-transmitting layer is formed on the elastic adhesive layer, and the protective film further includes a coating layer formed on the light-transmitting layer. The coating layer has a certain strength to further support the recess formed by the second package. The specific structure and required materials of the protective film are disclosed in the art and will not be detailed here. The protective film is mainly used for the protection of the display module surface, and in some products, it is also used to provide matte properties or black opacity.

[0020] This invention also discloses a method for repairing a display module. The display module includes a lamp board with a plurality of LEDs disposed on the lamp board, and each LED is encapsulated with a first encapsulation body. The method for repairing the display module includes: identifying a faulty LED in the display module and obtaining the coordinate information of the faulty LED; destroying the first encapsulation body at the location of the coordinate information to form a gap; removing the faulty LED from the gap and filling it with a new LED; and applying adhesive to the gap using the display module adhesive application method described above. Attached Figure Description

[0021] Figure 1 This is a flowchart of the glue application method for display modules in the first embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the process of applying adhesive to the display module in the first embodiment of the present invention.

[0023] Figure 3This is a structural diagram of the protective film of the present invention.

[0024] Figure 4 This is a flowchart of the glue application method for display modules in the second embodiment of the present invention.

[0025] Figure 5 This is a schematic diagram of the process of applying adhesive to the display module in the second embodiment of the present invention.

[0026] Figure 6 This is a schematic diagram of the process of the glue application method for the display module in the third embodiment of the present invention.

[0027] Figure 7 This is a schematic diagram of the process of applying adhesive to the display module in the fourth embodiment of the present invention. Detailed Implementation

[0028] To illustrate the technical content, structural features, objectives, and effects of the present invention in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0029] refer to Figure 1 and Figure 2 This invention discloses a method 100 for applying adhesive to a display module. The display module includes a lamp board 11, a plurality of LED beads 12 mounted on the lamp board 11, and a first encapsulation body 13 encapsulated on the LED beads 12. (See reference...) Figure 2 (a) When applying glue, the first package 13 has a notch 14; the display module glue application method 100 includes steps S11 to S13.

[0030] Step S11, refer to as follows Figure 2 (b) Fill the notch 14 with encapsulating adhesive 15.

[0031] Step S12, refer to Figure 2 (c) The encapsulating adhesive 15 is cured to form a second encapsulation 16, the lowest point of the upper surface of the second encapsulation 16 being lower than the surface of the first encapsulation 13, and the highest point of the upper surface of the second encapsulation 16 being lower than the surface of the first encapsulation 13. Of course, the highest point of the upper surface of the second encapsulation 16 can also be equal to the surface of the first encapsulation 13 (e.g., ...). Figure 5 (As shown).

[0032] Specifically, a hot press block 20 is used to at least partially extend into the notch 14 to hot press the encapsulating adhesive 15 within the notch 14, so that the encapsulating adhesive 15 is molded to form a second encapsulation 16 (e.g., Figure 2 (c) and Figure 2(d) As shown in the figure. In this case, after the hot press block 20 presses the encapsulating adhesive 15, the encapsulating adhesive 15 is at least partially cured to form the second encapsulation 16. The second encapsulation can then be baked and cured. Alternatively, the encapsulating adhesive 15 can be cured directly by the hot press block 20 while it is being molded to form the second encapsulation 16.

[0033] Step S13, refer to Figure 2 (e) A protective film 17 is attached to the surface of the first package 13 and the second package 16.

[0034] refer to Figure 3 The protective film 17 includes an elastic adhesive layer 171 and a light-transmitting layer 172, wherein the elastic adhesive layer 171 is the bottom layer of the protective film 17.

[0035] In this embodiment, the elastic adhesive layer 171 includes a pressure-sensitive adhesive layer. The light-transmitting layer 172 includes a polyester film layer.

[0036] refer to Figure 3 The light-transmitting layer 172 is formed on the elastic adhesive layer 171, and the protective film 17 further includes a coating layer 173 formed on the light-transmitting layer 172. Wherein, the first encapsulation body 13 and the second encapsulation body 16 are epoxy resin, silicone or fluorocarbon resin, and the first encapsulation body 13 and the second encapsulation body 16 are made of the same material.

[0037] In this embodiment, the surface of the second package 16 is uneven, and the highest and lowest points of its upper surface are located on different horizontal planes.

[0038] Specifically, when filling the gap 14 with encapsulating adhesive 15, the amount of encapsulating adhesive 15 is less than the volume of the gap 14, so that there is a first difference Δh between the upper surface of the filled encapsulating adhesive 15 and the upper edge of the gap 14 (e.g., ...). Figure 2 As shown in (b), the first difference Δh is less than or equal to the depth h0 of the hot press block 20 extending into the notch 14 and is greater than 0. Wherein, when the notch 14 is filled with encapsulating adhesive 15, the distance from the upper surface of the filled encapsulating adhesive 15 to the upper surface of the lamp bead 12 is h1 (e.g., ...). Figure 2 As shown in (b), h0 < (h1 + Δh), ensuring that the hot press block 20 does not touch the lamp bead 12. In this embodiment, the molding adhesive layer of the hot press block 20 is H higher than the upper surface of the lamp bead 12, where H = (h1 + Δh - h0), and the range of H is 50-70 μm, ensuring that the adhesive layer thickness on the lamp bead 12 after hot pressing is greater than or equal to 50 μm.

[0039] refer to Figure 2In the first embodiment, the end dimension of the hot press block 20 is smaller than that of the notch 14, so that an overflow area is formed between the hot press block 20 and the notch 14, allowing excess encapsulating adhesive 15 to overflow into the overflow area when the hot press block 20 presses the encapsulating adhesive 15 (e.g., when the hot press block 20 presses the encapsulating adhesive 15). Figure 2 (As shown). Not limited thereto, in another embodiment, excess encapsulating adhesive 15 also overflows from the area between the hot press block 20 and the notch 14 outside the notch (as shown). Figure 5 (As shown).

[0040] Preferably, the end of the hot-pressing block 20 gradually tapers so that the hot-pressing surface at the end of the hot-pressing block 20 is platform-shaped. In this embodiment, the platform-shaped hot-pressing block 20 has a space at its edge for the encapsulating adhesive 15 to overflow, facilitating the outflow of the encapsulating adhesive 15. Of course, it is not limited to this; the end of the hot-pressing block 20 can also be a shape that matches the notch 14, simply by providing a channel or groove on the hot-pressing block 20 that communicates with the outside and allows the encapsulating adhesive 15 to be removed (not shown in the figure). Of course, in another embodiment, the end of the hot-pressing block 20 can also be a shape that matches the notch 14, and several recesses are formed on the hot-pressing surface at the end of the hot-pressing block to form an overflow area for the encapsulating adhesive (e.g., Figure 6 (As shown).

[0041] The size of the part of the hot pressing block 20 that extends into the notch 14 and is flush with the upper edge of the notch 14 should match the size of the notch 14 or be slightly smaller than the notch 14.

[0042] refer to Figure 4 and Figure 5 In the second embodiment, when the hot-pressing block 20 presses the encapsulating adhesive 15 into the notch 14, the encapsulating adhesive 15 overflows from the overflow area of ​​the notch 14. In this embodiment, before step S12, the method further includes step S12a, referring to... Figure 5 (c) An isolation layer 30 is provided around the notch 14; between steps S12 and S13, step S12b is also included, referring to... Figure 5 (d) and Figure 5 (e) Remove the isolation layer 30 and peel off the excess encapsulating adhesive 15 that has been hot-pressed onto the notch 14 by the hot press block 20. Step S12a can be performed between steps S11 and S12, or before step S11.

[0043] Specifically, refer to Figure 5 After the hot pressing block 20 extends into the notch 14, the position of the hot pressing block 20 flush with the upper edge of the notch 14 has a first dimension, and the entrance of the notch 14 has a second dimension. The difference between the second dimension and the first dimension is less than or equal to a preset value and greater than or equal to 0, so that when the encapsulating adhesive 15 overflows from the overflow area to the outside of the notch 14, the adhesive residue in the part flush with the notch 14 is very fine and easy to remove.

[0044] refer to Figure 6 Unlike the second embodiment, in the third embodiment, when the hot press block 20 presses the encapsulating adhesive 15 into the notch 14, the encapsulating adhesive 15 only overflows to the overflow area on the outer side of the platform at the end of the hot press block 20, and does not overflow the notch 14. In this embodiment, it is not necessary to set the isolation layer 30, nor is it necessary to peel off the isolation layer 30 and the excess material after the second encapsulation body 16 has cured.

[0045] refer to Figure 6 The end face of the hot-pressing block 20 has a hot-pressing surface, and several grooves are formed on the hot-pressing surface. When the hot-pressing block 20 presses the encapsulating adhesive 15 in the notch 14, while the encapsulating adhesive 15 is being pressed by the hot-pressing surface, some of the encapsulating adhesive 15 flows into the grooves in the hot-pressing surface and does not overflow the notch 14. In this embodiment, the groove is an annular groove, a strip groove, or a crisscrossing groove.

[0046] In this embodiment, after the encapsulating adhesive 15 is cured by the hot press block 20, the second encapsulated body 16 formed has a plurality of protrusions 161.

[0047] Whether the encapsulating adhesive 15 overflows into the notch 14 is determined by the area of ​​the hot-pressing surface of the hot-pressing block 20, the difference between the depth h0 and Δh of the hot-pressing block 20 extending into the encapsulating adhesive 15, the space between the hot-pressing block 20 and the notch 14 after the hot-pressing block 20 extends into the notch 14, and the volume of the hot-pressing block 20 recessed into the hot-pressing surface. In other words, it is determined by the amount or height of the encapsulating adhesive 15 filled into the notch 14. If a more precise filling method is used, an appropriate amount of encapsulating adhesive 15 can be filled into the notch 14 so that after the hot-pressing block 20 extends into the hot-pressing encapsulating adhesive 15, only a portion of the encapsulating adhesive 15 overflows into the notch 14, rather than overflowing. If a less precise filling method is used, it is preferable to set an isolation layer 30 and fill it with sufficient encapsulating adhesive 15. This method can effectively reduce the size of the depression on the surface of the second encapsulation body 16, making it easier for the elastic adhesive layer at the bottom of the protective film 17 to fill the depression.

[0048] In the above embodiments, the hot-pressing surface is a horizontal plane.

[0049] refer to Figure 7 In the fourth embodiment of the present invention, the end of the hot pressing block 20 is densely covered with a plurality of serrated grooves, so that after the hot pressing block 20 hot presses the encapsulating adhesive 15, the surface of the second encapsulation body 16 is serrated. This solution can effectively reduce the uniform texture on the surface of the second encapsulation body 16, which not only facilitates the elastic adhesive layer at the bottom of the protective film 17 to fill the depression, but also effectively reduces the adverse optical effects on the second encapsulation body 16 after repair.

[0050] The present invention also discloses a method for repairing a display module. The display module includes a lamp board 11, on which a plurality of lamp beads 12 are disposed, and each lamp bead 12 is encapsulated with a first encapsulation body. The method for repairing the display module includes: 1. identifying a faulty lamp bead 12 in the display module and obtaining the coordinate information of the faulty lamp bead 12; 2. destroying the first encapsulation body at the location of the coordinate information to form a gap 14; removing the faulty lamp bead 12 from the gap 14 and filling it with a new lamp bead 12; 3. applying glue to the gap 14 using the display module glue application method 100 described above.

[0051] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A display module gumming method, characterized in that: The LED beads of the display module are encapsulated with a first package, and the first package has a notch. The method for applying adhesive to the display module includes: Step 1: Fill the notch with sealing adhesive; Step 2, Curing the encapsulating adhesive to form a second encapsulation: Using a hot press block, at least partially inserted into the notch, the encapsulating adhesive in the notch is hot-pressed to form the encapsulating adhesive to form a second encapsulation. The lowest point of the upper surface of the second encapsulation is lower than the surface of the first encapsulation, and the highest point of the upper surface of the second encapsulation is lower than or equal to the surface of the first encapsulation. Step 3: Apply a protective film to the surface of the first package and the second package. The protective film includes an elastic adhesive layer and a light-transmitting layer, with the elastic adhesive layer being the bottom layer of the protective film.

2. The method for applying adhesive to a display module as described in claim 1, characterized in that: When filling the gap with encapsulating adhesive, the amount of encapsulating adhesive is less than the volume of the gap, so that there is a first difference Δh between the upper surface of the filled encapsulating adhesive and the upper edge of the gap. The first difference Δh is less than or equal to the depth h0 of the hot pressing block extending into the gap and is greater than 0. When filling the gap with encapsulating adhesive, the distance from the upper surface of the filled encapsulating adhesive to the upper surface of the lamp bead is h1, and h0 < (h1 + Δh).

3. The method for applying adhesive to a display module as described in claim 1, characterized in that: The end dimension of the hot press block is smaller than the dimension of the notch, so that an overflow area is formed between the hot press block and the notch.

4. The method for applying adhesive to a display module as described in claim 1, characterized in that: The hot press block tapers gradually at its end to form a platform shape.

5. The method for applying adhesive to a display module as described in claim 1, characterized in that: After the hot pressing block extends into the notch, the position where the hot pressing block is flush with the upper edge of the notch has a first dimension, and the notch entrance has a second dimension. The difference between the second dimension and the first dimension is less than or equal to a preset value and greater than or equal to 0.

6. The method for applying adhesive to a display module as described in claim 1, characterized in that: The end of the hot pressing block forms a horizontal hot pressing surface; or the end of the hot pressing block includes a plurality of densely distributed serrated grooves, so that after the hot pressing block heat-presses the encapsulating adhesive, the surface of the second encapsulation body is serrated; or the end of the hot pressing block includes a horizontal hot pressing surface, and the hot pressing surface is recessed with a plurality of overflow recesses, so that after the hot pressing block heat-presses the encapsulating adhesive, the surface of the second encapsulation body is convex with a plurality of protrusions.

7. The method for applying adhesive to a display module as described in claim 1, characterized in that: The procedure before step two includes: setting an isolation layer around the notch; and the procedure between step two and step three includes: removing the isolation layer and tearing off the excess encapsulating adhesive that has been hot-pressed onto the notch by the hot press block.

8. The method for applying adhesive to a display module as described in claim 1, characterized in that: The elastic adhesive layer includes a pressure-sensitive adhesive layer, the light-transmitting layer includes a polyester film layer, the light-transmitting layer is formed on the elastic adhesive layer, and the protective film further includes a coating layer formed on the light-transmitting layer.

9. A method for reworking a display module, the display module comprising a lamp board, wherein a plurality of lamp beads are disposed on the lamp board, and a first encapsulation body is encapsulated on each lamp bead; characterized in that: Identify faulty LEDs in the display module and obtain the coordinate information of the faulty LEDs; The first encapsulation at the location of the coordinate information is destroyed to form a gap; Remove the faulty LED from the notch and replace it with a new one; The gap is filled with adhesive using the display module filling method as described in any one of claims 1-8.

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