Film-covered display module and its production process and rework process

Abstract

The present invention provides a film-coated display module and a production process and a rework process thereof, wherein the film-coated display module comprises a film and a substrate, and one side of the substrate has a plurality of LED substrates. The film comprises a film structure and a glue layer covering one side of the film structure. The glue layer comprises a first glue layer and a second glue layer surrounding the first glue layer, and the first glue layer and the second glue layer cover the plane of the film structure facing the chip side. The bonding force of the second glue layer is greater than that of the first glue layer, and the film structure is adhered to the substrate by means of the first glue layer and the second glue layer. Compared with the prior art, the film-coated display module of the present invention can avoid warping, white edges, etc. on the edge of the film structure, and can greatly reduce the risk of debonding.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic component packaging, and in particular to a film-covered display module and a production process and a rework process thereof. Background Art

[0002] The display module usually includes a PCB board and a plurality of LED chips mounted on one side of the PCB board in a rectangular array. In order to prevent the LED chips from being directly exposed to the air and easily contaminated or damaged by human factors, which may affect or destroy the chip function, it is usually necessary to use a film to package the side of the PCB board where the LED chips are mounted. This packaging method has high requirements for equipment and process.

[0003] Generally speaking, the coating includes a base layer and a multi-layer functional layer disposed on the base layer. The display module is encapsulated on the coating by means of the adhesive layer disposed on the base layer to obtain a film-coated display module. The current film-coated display modules have the following problems: (1) After the display module and the coating are bonded together, the edges of the coating are prone to warping and white edges, and the encapsulation effect is poor, which ultimately affects the display effect. (2) The operating temperature of the LED chip is generally 50-70°C. Most of the adhesive layers have weak adhesion in this temperature range, and there is a greater risk of debonding. Summary of the invention

[0004] Based on the above problems, the object of the present invention is to provide a new film-coated display module and its production process and rework process. The film-coated display module has good packaging effect and low debonding risk.

[0005] To achieve the above-mentioned purpose, the first aspect of the present invention provides a film-coated display module, comprising a film and a substrate, one side of the substrate having a plurality of LED chips, the film comprising a film structure and a glue layer covering one side of the film structure, the glue layer comprising a first glue layer and a second glue layer surrounding the first glue layer, the first glue layer and the second glue layer covering the plane of the film structure facing the chip side, the bonding force of the second glue layer being greater than that of the first glue layer, and the film structure being adhered to the substrate by means of the first glue layer and the second glue layer.

[0006] Compared with the prior art, the adhesive layer between the film structure and the substrate in the film-covered display module of the present invention includes a first adhesive layer and a second adhesive layer surrounding the first adhesive layer. At the same time, the first adhesive layer and the second adhesive layer cover the plane of the film structure facing the chip, and the adhesive force of the second adhesive layer is greater than that of the first adhesive layer. In other words, the second adhesive layer with higher adhesive force is arranged around the edges of the film structure, thereby preventing the edges of the film structure from warping, white edges, etc. In addition, the adhesive force of the second adhesive layer is relatively large, so the risk of debonding can be greatly reduced.

[0007] Preferably, the membrane structure is formed by stacking multiple layers, and the membrane structure includes a base layer, the adhesive layer is arranged on one side of the base layer, and the functional layer is arranged on the opposite side.

[0008] Preferably, the functional layer is at least one of an anti-fingerprint layer, a reflective layer and a hardening layer.

[0009] Preferably, the material of the first adhesive layer is OCA optical adhesive.

[0010] Preferably, the material of the second adhesive layer is a repairable optical structural adhesive. When the display module needs to be repaired, the first adhesive layer and the second adhesive layer are heated to reduce the bonding force of the first adhesive layer, and the film structure and the substrate are peeled off by external force, thereby repairing the LED chip on the substrate.

[0011] Preferably, the distance from the edge of the first adhesive layer to the edge of the second adhesive layer on the side away from the first adhesive layer is 1 to 3 mm.

[0012] A second aspect of the present invention provides a production process of a film-coated display module, wherein the film-coated display module comprises a film structure and a substrate, comprising the steps of:

[0013] (1) a first adhesive layer is provided in the middle of one side of the membrane structure, and a portion of the membrane structure on the same side where the first adhesive layer is not provided is a non-adhesive area;

[0014] (2) filling the adhesive-free area with a second adhesive layer, or providing a second adhesive layer in a region of the substrate corresponding to the adhesive-free area, wherein the adhesive force of the second adhesive layer is greater than that of the first adhesive layer;

[0015] (3) The film structure and the substrate are bonded together by means of the first adhesive layer and the second adhesive layer, and the first adhesive layer and the second adhesive layer are cured to obtain a film-coated display module.

[0016] The film-covered display module production process adopted by the present invention is simple and effective to operate, and the packaging effect can be ensured and the risk of debonding can be reduced by setting the first adhesive layer and the second adhesive layer.

[0017] Preferably, the second adhesive layer is filled in the adhesive-free area or an area of ​​the substrate corresponding to the adhesive-free area by spraying, dispensing, scraping or coating.

[0018] Preferably, the size of the adhesive-free area from the first adhesive layer to the edge of the membrane structure is 1 to 3 mm.

[0019] Preferably, the lamination conditions are: temperature 60-120° C., pressure 0.2-0.8 MPa.

[0020] Preferably, the curing conditions are: humidity ≥ 60%, and curing at room temperature for 45 to 50 hours.

[0021] A third aspect of the present invention provides a repair process for a film-coated display module, wherein the film-coated display module is repaired, comprising the steps of:

[0022] (1) heating the film-covered display module until the adhesive force of the first adhesive layer is reduced, so that the first adhesive layer and the second adhesive layer between the film structure and the substrate fall off to achieve separation of the film structure and the substrate;

[0023] (2) Repairing defective LED chips on the substrate;

[0024] (3) providing a new membrane structure, wherein a first adhesive layer is also disposed in the middle of one side of the new membrane structure, and an adhesive-free area is disposed around the first adhesive layer;

[0025] (4) filling a new second adhesive layer in the new adhesive-free area of ​​the film structure, or providing a new second adhesive layer in the area of ​​the substrate corresponding to the adhesive-free area;

[0026] (5) The new film structure and the substrate are bonded together by means of the first adhesive layer and the second adhesive layer, and the first adhesive layer and the second adhesive layer are cured to obtain a repaired film-covered display module.

[0027] The repair process of the film-coated display module adopted by the present invention is simple and effective to operate. The arrangement of the first adhesive layer and the second adhesive layer can not only ensure the encapsulation effect and reduce the risk of debonding, but also enable the display module to be repaired.

[0028] Preferably, the heating temperature in step (1) is 70-95°C.

[0029] Preferably, the second adhesive layer is filled in the adhesive-free area or an area of ​​the substrate corresponding to the adhesive-free area by spraying, dispensing, scraping or coating.

[0030] Preferably, the lamination conditions are: temperature 60-120° C., pressure 0.2-0.8 MPa.

[0031] Preferably, the curing conditions are: humidity ≥ 60%, and curing at room temperature for 45 to 50 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 FIG. 4 is a schematic diagram of a film-covered display module according to the present invention.

[0033] Component Symbols

[0034] 100-film-coated display module; 10-film; 11-membrane structure; 111-base layer; 113-functional layer; 113a-anti-fingerprint layer; 113b-reflective layer; 113c-hardening layer; 13-glue layer; 131-first glue layer; 133-second glue layer; 30-substrate; 31-LED chip DETAILED DESCRIPTION

[0035] The present invention provides a film-covered display module with good packaging effect and low risk of debonding. Figure 1 As shown, the film-type display module 100 includes a film 10 and a substrate 30, one side of the substrate 30 has a plurality of LED chips 31, the film 10 includes a film structure 11 formed by stacking multiple layers and a glue layer 13 covering one side of the film structure 11, the glue layer 13 includes a first glue layer 131 and a second glue layer 133 surrounding the first glue layer 131, the first glue layer 131 and the second glue layer 133 cover the plane of the film structure 11 facing the substrate 30, and the film structure 11 is adhered to the substrate 30 by the first glue layer 131 and the second glue layer 133. The distance from the edge of the first glue layer 131 to the edge of the second glue layer 133 on the side away from the first glue layer 131 is 1 to 3 mm.

[0036] Continue as Figure 1 As shown, the film structure 11 includes a base layer 111, a glue layer 13 is disposed on one side of the base layer 111, and a functional layer 113 is disposed on the opposite side. The functional layer 113 is at least one of an anti-fingerprint layer, a reflective layer and a hardening layer, such as Figure 1 As shown, a hardening layer 113c, a reflective layer 113b and an anti-fingerprint layer 113a are sequentially arranged on the base layer 111. The base layer 111 can be a PET layer. The film structure 11 can be prepared by a conventional method of compounding a base and a functional layer, which is not the focus of the present invention, so it will not be repeated here.

[0037] It should be further explained that the material of the first adhesive layer 131 is PSA adhesive, preferably OCA optical adhesive. The bonding force of OCA optical adhesive is greatly affected by temperature. Its bonding force at room temperature can adhere the film structure 11 to the substrate 30. When the film-coated display module 100 is in working state, the temperature can reach 50-70°C. At this time, the bonding force of OCA optical adhesive is greatly reduced. If OCA optical adhesive is used alone to bond the film structure 11 and the substrate 30, there will be a high risk of debonding. The adhesive force of the second adhesive layer 133 is greater than that of the first adhesive layer 131. The material of the second adhesive layer 133 is optical structural adhesive, and its main components may include but are not limited to silicone, hot melt adhesive, UV adhesive, etc. This optical structural adhesive is not sensitive to temperature, and has an adhesive force of 2 to 3Mpa at -40 to 200°C. The adhesive force is moderate and has repairability. In the absence of external force, the membrane structure 11 and the substrate 30 can be firmly bonded together, and there is no risk of debonding. The repairable optical structural adhesive can only be peeled off when subjected to a certain degree of external force. If the optical structural adhesive is used alone, although it can meet the two requirements of anti-debonding and repairability, the optical structural adhesive is covered on the entire surface of the membrane structure 11. When the situation of repair is required, the external force to be applied is also not small. Therefore, the first adhesive layer 131 and the second adhesive layer 133 are combined, and the second adhesive layer with greater adhesive force and low temperature sensitivity of adhesive force is arranged on the periphery of the first adhesive layer 131 with high temperature sensitivity. The packaging effect of the film-coated display module 100 can be improved, the risk of debonding can be reduced, and the difficulty of rework is small. In addition, the thickness of the second adhesive layer 133 is preferably consistent with the thickness of the first adhesive layer 131 to enhance the connection reliability.

[0038] The substrate 30 of the present invention can be a conventional PCB substrate. The LED chip is usually welded to the PCB substrate by laser welding, reflow soldering, etc., and then the film 10 is bonded to the side of the PCB substrate with the LED chip to obtain a film-coated display module. The LED chip can specifically be a MiniLED chip or a Micro LED chip.

[0039] The production process of the film-covered display module of the present invention may include the following steps:

[0040] (1) a first adhesive layer is provided in the middle of one side of the membrane structure, and a portion of the membrane structure on the same side where the first adhesive layer is not provided is a non-adhesive area;

[0041] (2) filling the non-glue area with a second glue layer, or providing a second glue layer in a region of the substrate corresponding to the non-glue area, wherein the bonding force of the second glue layer is greater than that of the first glue layer;

[0042] (3) The film structure and the substrate are bonded together by means of a first adhesive layer and a second adhesive layer, and the first adhesive layer and the second adhesive layer are cured to obtain a film-coated display module.

[0043] In the production process of the above-mentioned film-coated display module, in step (1), the first adhesive layer is cut around, and after being bonded to the membrane structure, an exposed area can be left near the edges of the membrane structure, and this exposed area is the adhesive-free area. In step (2), the second adhesive layer is filled in the adhesive-free area or the area of ​​the substrate corresponding to the adhesive-free area by spraying, dispensing, scraping or coating. The size of the adhesive-free area from the first adhesive layer to the edge of the membrane structure is 1 to 3 mm. The amount of the second adhesive layer filled should be sufficient to ensure that its thickness is consistent with the thickness of the first adhesive layer after bonding. In step (3), the bonding conditions are: temperature 60 to 120°C, pressure 0.2 to 0.8 MPa. During curing, place the bonded membrane structure with one side facing down on a smooth plane, and cure it at room temperature for 45 to 50 hours, preferably 48 hours, in an environment with a humidity of ≥60%.

[0044] The film-coated display module of the present invention can also be repaired to obtain a repaired film-coated display module, and the repair process includes:

[0045] (1) heating the film-coated display module until the adhesive force of the first adhesive layer is reduced, so that the first adhesive layer and the second adhesive layer between the film structure and the substrate fall off to achieve separation of the film structure and the substrate;

[0046] (2) Repair defective LED chips on the substrate;

[0047] (3) providing a new membrane structure, wherein a first adhesive layer is also disposed in the middle of one side of the new membrane structure, and an adhesive-free area is disposed around the first adhesive layer;

[0048] (4) filling a new second adhesive layer in the adhesive-free area of ​​the new film structure, or providing a new second adhesive layer in the area of ​​the substrate corresponding to the adhesive-free area;

[0049] (5) The new film structure and the substrate are bonded together by means of a first adhesive layer and a second adhesive layer, and the first adhesive layer and the second adhesive layer are cured to obtain a repaired film-coated display module.

[0050] In the repair process of the film-coated display module, in step (1), the film-coated display module is heated until the adhesive force of the first adhesive layer is reduced, and the specific heating temperature can be 70-95°C; the second adhesive layer is not sensitive to temperature, and has an adhesive force of 2-3Mpa at -40-200°C, which is moderate and has repairability. After heating, an external force is applied to the film structure to peel off the film structure and the substrate. After peeling, the substrate can be re-encapsulated with the new film, that is, the operations of steps (2) to (5) are performed.

[0051] Wherein, in step (4), the second adhesive layer is filled in the adhesive-free area or the area of ​​the substrate corresponding to the adhesive-free area by spraying, dispensing, scraping or coating. The size of the adhesive-free area from the first adhesive layer to the edge of the membrane structure is 1 to 3 mm. The amount of the second adhesive layer filled should be sufficient to ensure that its thickness is consistent with the thickness of the first adhesive layer after bonding. In step (5), the bonding conditions are: temperature 60 to 120°C, pressure 0.2 to 0.8 MPa. During curing, place the bonded membrane structure with one side facing down on a smooth plane, and cure it at room temperature for 45 to 50 hours, preferably 48 hours, in an environment with a humidity of ≥60%.

[0052] In order to better illustrate the purpose, technical scheme and beneficial effects of the present invention, the present invention will be further described below in conjunction with specific embodiments. It should be noted that the following implementation method is a further explanation of the present invention and should not be used as a limitation of the present invention.

[0053] Example 1

[0054] The production process of the film-covered display module may include the following steps:

[0055] (1) a first adhesive layer is provided in the middle of one side of the membrane structure, and the periphery of the first adhesive layer is cut so that the membrane structure is provided with an adhesive-free area around the first adhesive layer;

[0056] (2) Use glue spraying to fill the second glue layer in the glue-free area. The amount of the second glue layer filled should be such that its thickness after bonding is consistent with the thickness of the first glue layer;

[0057] (3) The film structure and the substrate are bonded together by means of a first adhesive layer and a second adhesive layer, with the side of the substrate provided with MiniLED facing the film structure. The bonding temperature is 100° C. and the pressure is 0.5 MPa. The bonded film structure is placed with one side facing downward on a smooth plane and cured at room temperature for 48 hours in an environment with a humidity of ≥60% to obtain a film-coated display module.

[0058] The film-coated display module obtained by this production process includes a multi-layer film and a substrate. The substrate has a plurality of LED chips on one side facing the film. The multi-layer film may include a film structure formed by stacking multiple layers and a glue layer covering one side of the film structure. The film structure includes a PET layer, and a hardening layer, a reflective layer and an anti-fingerprint layer arranged in sequence on the PET layer. The glue layer includes a first glue layer and a second glue layer surrounding the first glue layer and having the same thickness as the first glue layer. The first glue layer and the second glue layer cover the plane of the film structure facing the LED chip side, and the film structure is adhered to the substrate by the first glue layer and the second glue layer. The material of the first glue layer is OCA optical glue. The bonding force of the second glue layer is greater than that of the first glue layer. The material of the second glue layer is a repairable optical structural glue, the main component of which is silicone. This film-coated display module can be repaired, and can also avoid the phenomenon of warping and white edges on the edge of the film structure, and can also greatly reduce the risk of debonding.

[0059] Furthermore, when the display module needs to be repaired, the following steps can be performed to obtain a repaired film-coated display module.

[0060] (1) heating the film-coated display module to 80° C. and applying an external force to separate the film structure and the substrate;

[0061] (2) Repairing defective LED chips on the substrate;

[0062] (3) providing a new membrane structure, wherein a first adhesive layer is also disposed in the middle of one side of the new membrane structure, and an adhesive-free area is disposed around the first adhesive layer;

[0063] (4) Use glue spraying to fill the non-glue area with a new second glue layer;

[0064] (5) The new film structure and the substrate are bonded together by the first adhesive layer and the second adhesive layer at a bonding temperature of 100° C. and a pressure of 0.5 MPa. The bonded film structure is placed with one side facing downward on a smooth surface and cured at room temperature for 48 hours in an environment with a humidity of ≥60% to obtain a repaired film-coated display module.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention is described in detail with reference to the preferred embodiments, it is not limited to those listed in the embodiments. Those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A repair process for a film-covered display module, characterized in that: The film-coated display module comprises a film and a substrate, one side of the substrate has a plurality of LED chips, the film comprises a film structure and a glue layer covering one side of the film structure, the glue layer comprises a first glue layer and a second glue layer surrounding the first glue layer, the first glue layer and the second glue layer cover a plane of the film structure facing the chip, the bonding force of the second glue layer is greater than that of the first glue layer, and the film structure is adhered to the substrate by means of the first glue layer and the second glue layer, comprising the steps of: (1) heating the film-covered display module until the adhesive force of the first adhesive layer is reduced, so that the first adhesive layer and the second adhesive layer between the film structure and the substrate fall off to achieve separation of the film structure and the substrate; (2) Repairing defective LED chips on the substrate; (3) providing a new membrane structure, wherein a first adhesive layer is also disposed in the middle of one side of the new membrane structure, and an adhesive-free area is disposed around the first adhesive layer; (4) filling a new second adhesive layer in the new adhesive-free area of ​​the film structure, or providing a new second adhesive layer in the area of ​​the substrate corresponding to the adhesive-free area; (5) The new film structure and the substrate are bonded together by means of the first adhesive layer and the second adhesive layer, and the first adhesive layer and the second adhesive layer are cured to obtain a repaired film-covered display module.

2. The repair process of the film-coated display module according to claim 1, characterized in that: The membrane structure is formed by stacking multiple layers, and includes a base layer, the adhesive layer is arranged on one side of the base layer, and a functional layer is arranged on the opposite side.

3. The repair process of the film-covered display module according to claim 2, characterized in that: The functional layer is at least one of an anti-fingerprint layer, a reflective layer and a hardening layer.

4. The repair process of the film-coated display module according to claim 1, characterized in that: The material of the first adhesive layer is OCA optical adhesive.

5. The repair process of the film-coated display module according to claim 4, characterized in that: The material of the second adhesive layer is repairable optical structural adhesive.

6. The repair process of the film-covered display module according to claim 1, characterized in that: The distance from the edge of the first adhesive layer to the edge of the second adhesive layer on the side away from the first adhesive layer is 1 to 3 mm.

7. The repair process of the film-coated display module according to claim 1, characterized in that: The heating temperature in step (1) is 70-95°C.

8. The repair process of the film-coated display module according to claim 1, characterized in that: The second glue layer is filled in the glue-free area or the area of ​​the substrate corresponding to the glue-free area by spraying, dispensing, scraping or coating.

9. The repair process of the film-coated display module according to claim 1, characterized in that: The lamination conditions are: temperature 60-120° C., pressure 0.2-0.8 MPa.

10. The repair process of the film-covered display module according to claim 1, characterized in that: The curing conditions are: humidity ≥ 60%, and curing at room temperature for 45 to 50 hours.

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