Method for eliminating bubbles in the lamination of medium-sized display modules

Abstract

The present invention discloses a method for eliminating bubbles in the lamination of medium-sized display modules, comprising: step 1: laminating a cover plate onto a display module, placing the display module horizontally with the cover plate facing upward, placing a soft-bottomed extrusion device in the middle of the cover plate and leaving it there for a period of time; step 2: removing the extrusion device, vacuuming the display module, and UV curing after the vacuuming is completed; step 3: inspecting whether the display module is properly laminated. The beneficial effects of the present invention are: bubbles in the middle of the display module can be expelled by the extrusion device, which helps to improve the bubble elimination effect, reduce the number of vacuuming operations and rework, and save time, labor, and material costs; by using a heavy object to press on the laminated OCA to observe whether it is well cured, the result can be quickly judged, thereby accurately determining whether the laminate is properly laminated.

Description

Technical Field

[0001] The present invention relates to the technical field of display modules, and in particular to a method for eliminating bubbles in the lamination of a medium-sized display module. Background Art

[0002] During the current production and assembly process for LCD modules, a cover plate is bonded to the top surface of the LCD module using optical bonding adhesive (OCA). After the cover plate is bonded, bubbles may form and need to be removed. Due to the relatively large size of medium-sized display modules, bubbles in the center of the module are difficult to remove, requiring multiple vacuuming operations or re-bonding of the cover plate. Furthermore, existing inspection methods cannot effectively verify whether bubbles have been eliminated, which can affect subsequent processes and reduce product yield.

[0003] Therefore, the existing technology has defects and needs to be improved. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for eliminating bubbles in the lamination of a medium-sized display module.

[0005] The technical solution of the present invention is as follows: The present invention provides a method for eliminating bubbles in the bonding of a medium-sized display module, comprising the following steps: Step 1: bonding a cover plate to the display module, placing the display module horizontally with the cover plate facing upward, placing a soft-bottomed extrusion device in the middle position of the cover plate and leaving it there for a period of time; Step 2: removing the extrusion device, vacuuming the display module, and performing UV curing after vacuuming is completed; Step 3: inspecting whether the display module bonding is qualified.

[0006] Furthermore, step 3 includes: step 31: placing the display module horizontally with the cover facing upward, placing a weight with a round bottom at one corner of the cover or placing two weights with round bottoms at two opposite corners of the cover, wherein the round bottoms of the weights are tangent to two right-angled sides of the AA area of ​​the corresponding display module;

[0007] Step 32: After a period of time, observe through a magnifying glass or microscope whether bubbles appear near the area pressed by the weight;

[0008] Carry out steps 31 and 32 in sequence to complete the inspection of the four corners of the display module. If bubbles appear, the display module is judged to be unqualified. If no bubbles appear, the display module is qualified.

[0009] Furthermore, the weight of the weight is 2500g.

[0010] Furthermore, the time for the heavy object to press the cover plate is 1 minute.

[0011] Furthermore, in step 1, the extrusion device includes a rectangular iron block and a silicone pad arranged under the iron block, the thickness of the silicone pad is 1mm-2mm, the thickness of the middle position of the silicone pad is 0.2mm-0.3mm thicker than the thickness at the edge position, and the compression rate of the silicone pad is 20%-30%.

[0012] Furthermore, in step 1, the area of ​​the cover plate extruded by the extrusion device is two-thirds of the area of ​​the cover plate.

[0013] Furthermore, in step 1, the weight of the iron block is 2500 g.

[0014] Furthermore, the period of time in step 1 is 10 minutes to 20 minutes.

[0015] By adopting the above scheme, the beneficial effects of the present invention are: the bubbles in the middle of the display module can be discharged first through the extrusion device, which helps to improve the bubble elimination effect, reduce the number of vacuuming times and reduce rework, and save time costs, labor costs and material costs; by using heavy objects to press and observe whether the bonded OCA is well cured, the results can be quickly judged, thereby accurately judging whether the bonding is qualified. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Flowchart of the present invention.

[0017] Figure 2 This is a schematic diagram of the extrusion device in step 1 of the present invention being placed on the cover plate.

[0018] Figure 3 This is a schematic diagram of placing a heavy object at a corner of the display module in step 3 of the present invention. DETAILED DESCRIPTION

[0019] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Please refer to Figures 1 to 3 In this embodiment, the present invention provides a method for eliminating bubbles in the lamination of a medium-sized display module, comprising the following steps: Step 1: Lay a cover plate on the display module, place the display module horizontally with the cover plate facing upward, and place a soft-bottomed extrusion device in the middle of the cover plate and leave it there for a period of time.

[0021] Specifically, in step 1, the extrusion device includes a rectangular iron block and a silicone pad arranged under the iron block. The thickness of the silicone pad is 1mm-2mm, and the thickness of the middle position of the silicone pad is 0.2mm-0.3mm thicker than the thickness at the edge position. The compression rate of the silicone pad is 20%-30%. In step 1, the area of ​​the cover plate squeezed by the extrusion device can be two-thirds of the cover plate area, and the period of time is 10 minutes to 20 minutes. This setting form of the extrusion device can achieve a better bubble squeezing effect, and can squeeze the bubbles in the middle position of the display module to the edge position, which is convenient for the subsequent vacuum operation, so that the bubbles in the middle position are eliminated.

[0022] Step 2: Remove the extrusion device, vacuum the display module, and then perform UV curing;

[0023] Specifically, in step 2, the vacuuming operation can be performed once, or twice or more times depending on specific needs. The parameters of the vacuuming operation can be: pressure: 0.45±0.1MPa, temperature: 45±10°C, and time: 5 minutes. After the vacuuming, the display module with the cover plate attached can be UV-cured to solidify the OCA.

[0024] Step 3: Check whether the display module is properly fitted.

[0025] Specifically, step 3 includes: step 31: placing the display module horizontally with the cover facing upward, placing a weight with a round bottom at one corner of the cover or placing two weights with round bottoms at two opposite corners of the cover, wherein the round bottom of the weight is tangent to two right-angled sides of the AA area (Active Area) of the corresponding display module, and the weight can be a weight, weighing 2500 g and having a bottom diameter of 60 mm;

[0026] Step 32: After about 1 minute, observe whether bubbles appear near the area pressed by the weight through a 20x magnifying glass or above or a 100x magnifying microscope or above;

[0027] Steps 31 and 32 are performed sequentially to inspect the four corners of the display module. If bubbles are found, the display module is deemed unqualified. If no bubbles are found, the display module passes the lamination process. If bubbles are still found during the inspection, the energy parameters of the UV curing process need to be adjusted and UV curing performed again. If no bubbles are found during the inspection, the display module can be sent to the next process.

[0028] Because the display module is defoamed after being bonded to the cover plate, the human eye determines that there are no bubbles before UV curing of the OCA. However, the effectiveness of UV curing cannot be visually verified. If the OCA curing effect is not verified, bubbles may rebound over time, affecting the subsequent user experience. In step 3 of this solution, external pressure is applied to the bonded edges. If bubbles are generated or the OCA wrinkles, they can be clearly seen. The weights are placed at the four corners because the OCA edges are prone to shrinkage. If the OCA is not bonded properly or UV cured properly, bubbles are easily visible at the edges, thus achieving accurate detection.

[0029] In summary, the beneficial effects of the present invention are: the bubbles in the middle of the display module can be discharged first through the extrusion device, which helps to improve the bubble elimination effect, reduce the number of vacuuming times and rework, and save time costs, labor costs and material costs; by using heavy objects to press and observe whether the bonded OCA is well cured, the results can be quickly judged, thereby accurately judging whether the bonding is qualified.

[0030] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for eliminating bubbles in the lamination of medium-sized display modules, characterized in that: The following steps are involved: Step 1: Attach the cover to the display module. Place the display module horizontally with the cover facing upwards. Place a soft-bottomed extrusion device in the middle of the cover and leave it there for a while. Step 2: Remove the extrusion device, vacuum the display module, and then perform UV curing; Step 3 : Check whether the display module is properly fitted; Step 3 includes: Step 31: Place the display module horizontally with the cover facing upward, place a weight with a round bottom at one corner of the cover, or place two weights with round bottoms at two opposite corners of the cover, with the round bottoms of the weights tangent to the two right-angled sides of the AA area of ​​the corresponding display module; Step 32: After a period of time, observe through a magnifying glass or microscope whether there are bubbles near the area pressed by the weights; Steps 31 and 32 are performed in sequence to complete the inspection of the four corners of the display module. If bubbles are found, the display module is judged to be unqualified. If no bubbles are found, the display module is qualified.

2. The method for eliminating bubbles in laminating a medium-sized display module according to claim 1, characterized in that: The weight of the weight is 2500 g.

3. The method for eliminating bubbles in laminating a medium-sized display module according to claim 1, wherein: The time for the heavy object to press the cover plate is 1 minute.

4. The method for eliminating bubbles in laminating a medium-sized display module according to any one of claims 1 to 3, characterized in that: In step 1, the extrusion device includes a rectangular iron block and a silicone pad arranged under the iron block. The thickness of the silicone pad is 1mm-2mm, the thickness of the middle position of the silicone pad is 0.2mm-0.3mm thicker than the thickness at the edge position, and the compression rate of the silicone pad is 20%-30%.

5. The method for eliminating bubbles in laminating a medium-sized display module according to claim 4, characterized in that: In step 1, the area of ​​the cover plate extruded by the extrusion device is two-thirds of the area of ​​the cover plate.

6. The method for eliminating bubbles in laminating a medium-sized display module according to claim 4, characterized in that: In step 1, the weight of the iron block is 2500g.

7. The method for eliminating bubbles in laminating a medium-sized display module according to claim 4, characterized in that In the step 1, the period of time is 10 minutes to 20 minutes.

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