Liquid crystal display panel laminating process capable of preventing bubbles from being generated

Abstract

The invention relates to the technical field of liquid crystal display panel lamination, and discloses a liquid crystal display panel lamination process for preventing generation of bubbles, which comprises the following steps of: 1) directly laminating a touch screen (TP) on a module polaroid, and laminating the touch screen (TP) and a liquid crystal module (LCM) through frame lamination foam double faced adhesive tapes on four sides, the frame pasting foam double faced adhesive tape comprises a foam inner frame and a foam outer frame, and the foam inner frame is prepared in the mode that a TP VA single side is expanded outwards by 0.7-0.8 MM or above. According to the liquid crystal display panel laminating process capable of preventing the bubbles from being generated, the TP is directly laminated on the module polaroid, the upper polaroid is designed to be lower than the rubber frame surface, and according to the problems confronted by traditional full-laminated LCD assembly of traditional module structures, the existing backlight rubber frame mold can be utilized to the maximum extent based on the development of the laminating technology, so that the production efficiency is improved, and the production cost is reduced. The method has the advantages that bubbles caused by lamination of POL, OCA and TP on the module are avoided, the method is suitable for large-scale production of different specifications, the overall cost is reduced, the error rate is reduced, and the preparation and assembly yield is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid crystal display panel bonding, and specifically to a liquid crystal display panel bonding process for preventing the generation of bubbles. Background Art

[0002] The quality of a liquid crystal display mainly depends on its panel. Because the quality of the panel directly affects the viewing effect of the picture, and the liquid crystal TV panel accounts for more than half of the total cost of the whole machine, which is the main factor affecting the cost of the liquid crystal TV. Therefore, to select a good liquid crystal display, first of all, a good panel should be selected. The liquid crystal panel can largely determine very important parameters such as the brightness, contrast, color, and viewing angle of the liquid crystal display. The development speed of the liquid crystal panel is very fast. Common ones include TN panels, VA type panels such as MVA and PVA, IPS panels, and CPA panels.

[0003] At present, there are still some defects in the liquid crystal display panel bonding process. For example, when assembling these traditional module structures by traditional frame bonding LCD, there is a problem of poor bubbles caused by the bonding of POL, OCA, and TP on the module. The occurrence of this problem easily increases the unqualified product rate, raises the error rate, and greatly reduces the production effect. Therefore, we propose a liquid crystal display panel bonding process for preventing the generation of bubbles to solve the above problems. Summary of the Invention

[0004] (I) Technical Problems to be Solved

[0005] In view of the deficiencies of the prior art, the present invention provides a liquid crystal display panel bonding process for preventing the generation of bubbles, which has the advantage of avoiding poor bubbles caused by the bonding of POL, OCA, and TP on the module, and solves the problem of high error rate caused by poor bubbles caused by the bonding of POL, OCA, and TP on the module in the assembly of traditional frame bonding LCD with these traditional module structures.

[0006] (II) Technical Solutions

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] Preferably, a protective film, also known as a window protective film, is provided on the back surface of the TP. The protective film in the VA area of the product with foam is 0.40 mm smaller than the inner frame of the foam. If there is space, it should be processed as large as possible. The release tab of the protective film on the back surface of the TP is uniformly made of an easy-to-tear sticker, with a size of 15 * 25 mm (for 10.1 inches and above 10.1 inches). The easy-to-tear sticker is placed on the same side as the FPC, and the release tab is 1.00 mm away from the outer shape of the protective film, with the handle direction inward; the material requirement for the back protective film is T = 0.06 mm PU glue, a single-layer PET protective film, and the high-temperature resistance is 80 °C.

[0009] Preferably, the foam outer frame on the TP should avoid the FPC bonding end, with a 1.0 mm unilateral avoidance from the FPC pressing position. Moreover, the tolerance between the inner frame of the foam adhesive and the TP outer shape is + / -0.30 mm, and the position of the foam tear strip should be the same as the FPC wire outlet end.

[0010] Preferably, the double-sided foam adhesive is attached to the TP by the TP manufacturer before shipment. The double-sided foam adhesive is a composite material with a total thickness of 0.5 - 0.8 mm, consisting of TESA 4982 + foam + TESA 4982. The foam material is imported or domestic soft foam. After the frame-mounted double-sided foam adhesive is bonded to the TP, the thickness meets the defined compressed thickness in the foam specification.

[0011] Preferably, the frame-mounting tolerance between the module and the TP is controlled within ±0.2 mm (referring to the distance between the LCM AA and the TP VA), and the frame-mounting machine tolerance between the module and the TP is controlled within 0.3 mm (referring to the distance between the backlight edge of the module and the edge of the TP).

[0012] Preferably, the frame-mounted double-sided foam adhesive is designed in an L-shaped insertion method, with a maximum insertion gap of 0.3 mm.

[0013] Preferably, after the TP + LCM frame is bonded, the assembly is dot-glued. The specification is silicone glue 734, the glue application tool is a needle nozzle type, and the glue application position is the junction position of the foam adhesive.

[0014] Preferably, the polarizer of the module is selected with an upper grinding and lower polishing.

[0015] Another technical problem to be solved by the present invention is to provide a liquid crystal display panel bonding process for preventing the generation of bubbles, including the following steps:

[0016] 1): Directly attach the touch panel (TP) to the polarizer of the module. The touch panel (TP) and the liquid crystal module (LCM) are bonded through the frame-mounted double-sided foam adhesive on the four sides. Among them, the frame-mounted double-sided foam adhesive includes an inner foam frame and an outer foam frame. The inner foam frame is prepared by expanding 0.7 - 0.8 MM or more unilaterally from the TPVA. While increasing the width of the foam block, the inner foam frame avoids the foam being misaligned and entering the TP and VA panel window areas, and the VA of the frame-mounted TP is prepared with a unilateral size greater than the LCM AA area by 0.5 MM;

[0017] 2): The size of the outer foam frame is internally reduced by 0.3 mm unilaterally according to the SENSOR shape. If the G + G structure TP and the LCM are frame-mounted, and the SENSOR shape > LCM shape, then the size of the outer foam frame is internally reduced by 0.3 mm unilaterally according to the module shape. The outer foam frame increases the width of the foam block to reduce the risk of light leakage. The requirement for the outer foam to press the polarizer edge unilaterally is 0.5 mm (TYP), 0.30 mm (MIN);

[0018] 3): Stick the foam on the SENSOR. Among them, the inner frame of the foam extends 0.8 mm outward on the TP VA, and the outer frame of the foam retracts 0.30 mm inward on the outer shape of the module. For large screens above 10.1 inches, the inner frame should extend 1.0 mm outward on the TP VA, and the outer frame of the foam retracts 0.50 mm inward on the outer shape of the module. The width of the glue should be above 1.00 mm, otherwise the die-cutting process cannot be made and adhered. A release film tearing position needs to be placed on the foam, and the color of the release film is selected as blue.

[0019] (III) Beneficial effects

[0020] Compared with the prior art, the present invention provides a liquid crystal display panel bonding process for preventing bubbles, having the following beneficial effects:

[0021] This liquid crystal display panel bonding process for preventing bubbles directly adheres the TP to the polarizer of the module. The design of the upper polarizer can be lower than the surface of the glue frame. According to the problems faced by assembling these traditional module structures in the traditional full-stick LCD, and based on the bonding technology development, it can maximize the utilization of the existing glue frame mold of the backlight, avoid the bubble defects caused by the bonding of POL, OCA and TP on the module, adapt to the large-scale production of different specifications, reduce the overall cost, and at the same time reduce the error rate and increase the preparation and assembly yield. Description of the drawings

[0022] Figure 1 It is a schematic structural diagram of the TP design;

[0023] Figure 2 It is a schematic structural diagram of the TP + foam + LCM frame sticker design. Specific embodiments

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0025] Please refer to Figure 1 and Figure 2 , in this embodiment, a liquid crystal display panel bonding process for preventing bubbles includes the following steps:

[0026] 1): Directly attach the touch panel (TP) to the module polarizer. The module polarizer is selected with an upper grinding and lower polishing finish. The touch panel (TP) and the liquid crystal module (LCM) are bonded together through the frame-mounted foam double-sided tape on all four sides. The frame-mounted foam double-sided tape is designed in an L-shaped plug-in manner, and the plug-in gap is 0.3mm Max. Among them, the frame-mounted foam double-sided tape includes an inner foam frame and an outer foam frame. The inner foam frame is prepared by expanding 0.7 - 0.8MM or more outward from the single side of TP VA. The inner foam frame increases the width of the foam blockage while avoiding the foam being misaligned and entering the TP and VA panel window areas. And the VA of the frame-mounted TP is prepared with a single side greater than 0.5MM of the LCM AA area;

[0027] Among them, the foam double-sided tape is attached to the TP by the TP manufacturer before shipment. The foam double-sided tape is a composite material with a total thickness of 0.5 - 0.8mm, TESA 4982 + foam + TESA 4982; the foam material is imported or domestic soft foam. After the frame-mounted foam double-sided tape is bonded to the TP, the thickness meets the defined compressed thickness in the foam specification. After the TP + LCM frame is bonded, the assembly is dispensed with glue. Among them, the specification is silicone glue 734, the dispensing tool is a needle nozzle type, and the dispensing position is the junction position of the foam glue.

[0028] It should be added that after coating, the effect needs to evenly cover the interface position of the foam glue, and there should be no obvious protrusions, overflows, etc. The foam glue is at the position of the 2-piece TP foam splicing, and glue needs to be applied along the edge.

[0029] In addition, the frame-mounted tolerance between the module and the TP is controlled within ±0.2mm (referring to the distance between LCM AA and TP VA), and the frame-mounted installation tolerance between the module and the TP is controlled within 0.3mm (referring to the distance between the backlight edge of the module and the edge of the TP).

[0030] It should be noted that there are two design types. General demanders can design according to 0.3MM. If the demander has key requirements, the minimum is 0.20MM, that is, follow up with the factory process according to 0.20MM.

[0031] 2): The size of the outer foam frame is reduced by 0.3mm inward from the single side of the SENSOR shape. If the G + G structure TP and the LCM are frame-mounted, and the SENSOR shape > the LCM shape, then the size of the outer foam frame is reduced by 0.3mm inward from the single side of the module shape. The outer foam frame increases the width of the foam blockage to reduce the risk of light leakage. The requirement for the foam to press the polarizer edge on a single side is 0.5mm (TYP), 0.30mm (MIN);

[0032] Among them, when the outer foam frame on the TP encounters the FPC bonding end, it needs to be avoided. Avoid a single side of 1.0mm of the FPC pressing position. Moreover, the tolerance from the inner foam frame of the foam glue to the TP shape is + / -0.30mm. The position of the foam tear tab should be the same as the FPC wire outlet end to facilitate the fixture and blister packaging.

[0033] 3): As shown in Figure 1 the back view of the TP and Figure 2 the back view of the assembly, the foam is pasted on the SENSOR. Among them, the inner frame of the foam is expanded by 0.8 mm on the TPVA, the outer frame of the foam is recessed by 0.30 mm on one side of the module shape. For large screens over 10.1 inches, the inner frame should be expanded by 1.0 mm on the TP VA, and the outer frame of the foam is recessed by 0.50 mm on the module shape. The glue width should be above 1.00 mm, otherwise the die-cutting process cannot be made and adhered. A release film tearing position needs to be placed on the foam, and the color of the release film is selected as blue.

[0034] Among them, as shown in Figure 1 a protective film is provided on the back of the TP, also known as the window protective film. When pasting the product with a foam frame, it avoids the situation of dust falling into the VA area and causing dirt or other sundries during the pasting process. The protective film in the VA area of the product with a foam is 0.40 mm smaller than the inner frame of the foam. If there is space, it should be processed as the largest. The tearing handle of the protective film on the back of the TP is uniformly made of an easy-tear sticker, with a size of 15*25 mm (for 10.1 inches and above 10.1 inches). The easy-tear sticker is placed on the same side as the FPC, and the tearing distance from the outer shape of the protective film is 1.00 mm, and the handle direction is inward; the material requirement of the back protective film is T = 0.06 mm PU glue, a single-layer PET protective film, and the high temperature resistance is 80 °C.

[0035] The beneficial effects of the present invention are: for the liquid crystal display panel pasting process to prevent bubbles, by directly pasting the TP on the polarizer of the module, the design of the upper polarizer can be lower than the glue frame surface, solving the problems faced by assembling these traditional module structures according to the traditional full-paste LCD, and based on the pasting technology development, it can maximize the use of the existing glue frame mold of the backlight, avoid the bubble defects caused by the POL, OCA and TP pasting on the module, adapt to the large-scale production of different specifications, reduce the overall cost, at the same time reduce the error rate, and increase the preparation and assembly yield.

[0036] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A liquid crystal display panel laminating process for preventing bubble generation, characterized in that: The following steps are involved: 1): The touch screen (TP) is directly attached to the module polarizer, and the touch screen (TP) and the liquid crystal module (LCM) are attached by the frame-attached foam double-sided adhesive on the four sides, wherein the frame-attached foam double-sided adhesive includes a foam inner frame and a foam outer frame, and the foam inner frame is prepared according to the TP VA single-side expansion of 0.7 to 0.8MM or more, and the foam inner frame increases the width of the foam shielding while preventing the foam from entering the TP and VA panel window area, and the VA of the frame-attached TP is prepared to be larger than 0.5MM on one side of the LCM AA area; 2): The size of the foam frame shrinks 0.3mm on one side according to the shape of the sensor. If the G+G structure TP is attached to the LCM frame, and the shape of the sensor is greater than the shape of the LCM, the size of the foam frame shrinks 0.3mm on one side according to the shape of the module. The width of the foam shielding is increased to reduce the risk of light leakage. The requirement for the foam to press the edge of the polarizer on one side is 0.5mm (TYP), 0.30mm (MIN); 3): Foam is pasted on the SENSOR, where the foam inner frame expands 0.8mm on the TP VA, and the foam outer frame shrinks 0.30mm on one side of the module shape. The inner frame of a large screen larger than 10.1 inches should expand 1.0mm on the TP VA, and the foam outer frame shrinks 0.50mm on the module shape. The glue width should be more than 1.00mm, otherwise the die-cutting process cannot be made and pasted. A release film tearing position must be placed on the foam, and the release film color should be blue.

2. A liquid crystal display panel laminating process for preventing bubble generation according to claim 1, characterized in that: A protective film is set on the back of the TP, also known as a window protective film. The protective film in the VA area of ​​the foam product is 0.40mm smaller than the foam inner frame. If there is space, it should be processed as large as possible. The protective film tear handle on the back of the TP is uniformly made of easy-tear stickers with a size of: 15*25mm (10.1 inches and above). The easy-tear sticker is placed on the same side as the FPC. The tear handle is 1.00mm away from the outer shape of the protective film, and the handle direction is inward; the material requirement for the back protective film is T=0.06mm PU glue, a single-layer PET protective film, and a high temperature resistance of 80°C.

3. The process for laminating a liquid crystal display panel to prevent bubble generation according to claim 2, characterized in that: The foam outer frame on the TP needs to avoid the FPC binding end, avoiding the FPC pressing position by 1.0mm on one side, and the tolerance from the foam glue inner frame to the TP shape is + / -0.30mm, and the foam tearing position should be the same as the FPC outlet end.

4. The process for laminating a liquid crystal display panel to prevent bubble generation according to claim 3, characterized in that: The foam double-sided adhesive is attached to the TP by the TP manufacturer before shipment. The foam double-sided adhesive is a composite material with a total thickness of 0.5-0.8mm, TESA 4982+foam+TESA 4982; the foam material is imported or domestically produced soft foam, and the thickness of the frame-mounted foam double-sided adhesive after being attached to the TP meets the thickness after compression defined in the foam specification book.

5. The process for laminating a liquid crystal display panel to prevent bubble generation according to claim 4, characterized in that: The frame mounting tolerance between the module and TP is controlled at ±0.2mm (referring to the distance between LCM AA and TP VA), and the frame mounting machine tolerance between the module and TP is controlled at 0.3mm (referring to the distance between the backlight edge of the module and the edge of the TP).

6. The process for laminating a liquid crystal display panel to prevent bubble generation according to claim 5, characterized in that: The frame-sticking foam double-sided tape is designed to be L-shaped plug-in, with a plug-in gap of 0.3mm Max.

7. A liquid crystal display panel laminating process for preventing bubble generation according to claim 6, characterized in that: After the TP+LCM frame is attached, the assembly is glued, wherein the specification is silicone glue 734, the glue application tool is a needle-nozzle type, and the glue application position is the junction of the foam glue.

8. The process for laminating a liquid crystal display panel to prevent bubble generation according to claim 1, characterized in that: The module polarizer is top-polished and bottom-polished.

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