OCA optical cement curing method

Abstract

The invention provides an OCA (Optical Clear Adhesive) curing method which comprises the following steps: arranging a UV (Ultraviolet) degradation dye or an aggregation-induced emission material on the surface of a first element, coating OCA, arranging a second element on the surface of the OCA, and applying a UV light source for curing, uV energy required by degradation of the UV degradation dye is consistent with UV energy required by curing of the OCA; or determining UV energy required for curing the OCA according to the luminescence property of the aggregation-induced emission material, wherein the luminescence property of the aggregation-induced emission material comprises one or more of fluorescence spectrum, fluorescence intensity and fluorescence brightness. According to the method provided by the invention, whether the curing energy of the OCA reaches the standard or not can be detected in an online visual manner or through fluorescence detection equipment, independent detection is not needed in the curing process, working procedures do not need to be added, and materials do not need to be disassembled to be wasted.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic devices, and particularly to a method for curing OCA optical adhesive. Background Art

[0002] OCA (Optically Clear Adhesive) optical adhesive is a special adhesive used for bonding transparent optical components (such as lenses, etc.), which is required to be colorless and transparent, have a light transmittance of more than 95%, good bonding strength, can be cured at room temperature or medium temperature, and have characteristics such as small curing shrinkage.

[0003] OCA optical adhesive is generally coated between two layers of structures, and the OCA adhesive is cured by ultraviolet irradiation to bond the two layers of structures. Among them, whether the curing of OCA optical adhesive meets the standard, that is, whether the OCA optical adhesive is completely cured, will affect the performance of the component. For example, if the curing energy of OCA optical adhesive does not meet the standard, problems such as component reliability problems or bubble rebound will occur. Summary of the Invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a method for curing OCA optical adhesive and a method for detecting whether the curing energy of OCA optical adhesive meets the standard. The curing method provided by the present application can online detect whether the curing energy of OCA meets the standard, reduce the occurrence of the phenomenon that the curing energy of OCA optical adhesive does not meet the standard, and improve the product yield.

[0005] The present application provides a method for curing OCA optical adhesive, including the following steps:

[0006] After setting a UV-degradable dye or an aggregation-induced emission material on the surface of the first component, coat the OCA optical adhesive, set the second component on the surface of the OCA optical adhesive, and apply a UV light source for curing;

[0007] The UV energy required for the degradation of the UV-degradable dye is consistent with the UV energy required for the curing of the OCA optical adhesive;

[0008] Or determine the UV energy required for the curing of the OCA optical adhesive according to the luminescence performance of the aggregation-induced emission material, and the luminescence performance of the aggregation-induced emission material includes one or several of fluorescence spectrum, fluorescence intensity or fluorescence brightness.

[0009] In some specific implementation manners, the first component is a screen module, and the second component is a cover plate.

[0010] In some specific implementation manners, the UV-degradable dye is arranged in a dot shape.

[0011] In some specific implementation manners, the UV-degradable dye is arranged at the corners and the center position of the first component.

[0012] In some specific implementation manners, the UV-degradable dye is micron-sized.

[0013] In some specific implementation manners, the degradation product of the UV-degradable dye is a transparent liquid substance.

[0014] In some specific implementation manners, the UV-degradable dye is a triphenylmethane dye.

[0015] In some specific implementation manners, when an aggregation-induced emission material is disposed on the surface of the first element, the solidification method includes:

[0016] Pre-establish a standard curve of the luminescence performance of the aggregation-induced emission material and the UV energy. When applying a UV light source for solidification, monitor the luminescence performance of the aggregation-induced emission material until it is consistent with the UV energy required for curing the OCA optical adhesive, and then stop the solidification.

[0017] In some specific implementation manners, the standard curve of the luminescence performance and the UV energy is one or more of a standard curve of fluorescence spectrum and UV energy, a standard curve of fluorescence intensity and UV energy, or a standard curve of fluorescence brightness and UV energy.

[0018] In some specific implementation manners, the standard curve of the luminescence performance and the UV energy is established according to the following method:

[0019] Treat the aggregation-induced emission material with gradient UV energy to obtain the luminescence performance of the aggregation-induced emission material at different UV energies respectively;

[0020] Establish a standard curve with the UV energy as the first coordinate and the luminescence performance of the aggregation-induced emission material as the second coordinate.

[0021] In some specific implementation manners, the luminescence performance is the fluorescence intensity.

[0022] In some specific implementation manners, the aggregation-induced emission (AIE) material can be disposed in a dot shape at the corners and the center position of the first element.

[0023] The OCA optical glue curing method provided by this application includes the following steps: After setting a UV-degradable dye on the surface of the first component, coat the OCA optical glue, set the second component on the surface of the OCA optical glue, and apply a UV light source for curing; the UV energy required for the degradation of the UV-degradable dye is consistent with the UV energy required for the curing of the OCA optical glue. Before coating the OCA optical glue, this application first sets a UV-degradable dye on the surface of the first component, whose degradation-required UV energy is consistent with the UV energy required for the curing of the OCA optical glue (that is, the UV energy required for the degradation of the UV-degradable dye is within the range of the UV energy required for the curing of the OCA optical glue), and then applies a UV light source for curing. During the curing process, it is possible to judge whether the curing of the OCA optical glue meets the standard according to the color degradation of the UV-degradable dye. For example, if the UV-degradable dye is completely degraded, it proves that the energy of the applied UC light source is also sufficient to make the curing of the OCA optical glue meet the standard. Therefore, the curing method provided by this application can visually detect whether the curing energy of the OCA optical glue meets the standard, without the need for separate detection during the curing process, without adding processes, and without disassembling and wasting materials. Moreover, the method provided by this application can reduce the occurrence of the phenomenon that the curing energy of the OCA optical glue does not meet the standard and improve the product yield.

[0024] Further, the degradation product of the UV-degradable dye is a transparent liquid substance, such as benzene, toluene, xylene, etc., which can be absorbed by the OCA optical glue, so that there will be no residue and it will not affect the appearance and display effects of the prepared components, such as the screen.

[0025] In addition, this application can also set an aggregation-induced emission material on the surface of the first component. After the OCA is cured and crosslinked, the restriction of intramolecular motion of the AIE causes the AIE to emit fluorescence under UV irradiation. By detecting the fluorescence emission performance of the AIE material, it is possible to online judge whether the curing energy of the OCA optical glue meets the standard, without the need for separate detection during the curing process, without adding processes, and without disassembling and wasting materials. Moreover, the method provided by this application can reduce the occurrence of the phenomenon that the curing energy of the OCA optical glue does not meet the standard and improve the product yield. Description of the Drawings

[0026] Figure 1 It is a schematic diagram of the setting of the UV-degradable dye in the embodiment of this application;

[0027] Figure 2 It is a schematic flow diagram of the curing method provided by the embodiment of this application;

[0028] Figure 3 It is a schematic diagram of the setting of the aggregation-induced emission material in the embodiment of this application. Detailed Embodiments

[0029] The present invention provides a method for curing OCA optical adhesive. Those skilled in the art can draw on the content of this article and appropriately modify the process parameters to implement it. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are all considered to be included in the present invention. The method and application of the present invention have been described through preferred embodiments. Relevant personnel can obviously make changes, or appropriately change and combine the methods and applications in this article without departing from the content, spirit, and scope of the present invention to implement and apply the technology of the present invention.

[0030] In the prior art, generally, a UV energy meter is used to detect whether the curing energy of the OCA optical adhesive meets the requirements. Taking a display screen as an example, generally, the OCA optical adhesive is coated between the screen module and the cover plate, and then the cumulative curing energy at different positions is simulated and tested on the curing equipment. The UV energy meter needs to be calibrated regularly. It is also possible to determine whether the curing meets the requirements by detecting the curing rate of the OCA optical adhesive. However, generally, the product needs to be disassembled, and the OCA adhesive at each position is taken to calculate the reaction rate by dissolving and measuring the weight difference before and after. Neither of these two methods can achieve real-time detection of whether the curing of the OCA optical adhesive meets the requirements, nor can the curing energy of the OCA optical adhesive be adjusted in a timely manner.

[0031] Based on this, the present application provides a method for curing OCA optical adhesive, including the following steps:

[0032] After setting a UV-degradable dye or an aggregation-induced emission material on the surface of the first component, coat the OCA optical adhesive, set the second component on the surface of the OCA optical adhesive, and apply a UV light source for curing;

[0033] The UV energy required for the degradation of the UV-degradable dye is consistent with the UV energy required for the curing of the OCA optical adhesive;

[0034] Alternatively, determine the UV energy required for the curing of the OCA optical adhesive according to the luminescence performance of the aggregation-induced emission material, and the luminescence performance of the aggregation-induced emission material includes one or more of fluorescence spectrum, fluorescence intensity, or fluorescence brightness.

[0035] The present application takes a display screen as an example to illustrate the method for curing OCA optical adhesive, that is, the first component is the screen module, and the second component is the cover plate. Those skilled in the art can understand that the method provided by the present application is not limited to the display screen, and any electronic device that needs to use the OCA optical adhesive can refer to the method disclosed in the present application.

[0036] In this application, a UV-degradable dye is first set on the surface of the screen module. The UV-degradable dye degrades into a colorless substance under ultraviolet light and can be used as an indicator to determine whether the curing energy of the OCA optical adhesive meets the requirements. In one implementation of this application, the UV-degradable dye is arranged in dots, that is, the UV-degradable dye is set at different positions on the surface of the screen module. Specifically, the UV-degradable dye is set at the corners and the center of the first component and can be planned according to the actual size of the screen module. Refer to Figure 1 , Figure 1 which is a schematic diagram of the setting of the UV-degradable dye in the embodiment of this application. Among them, 11 is the screen module and 12 is the UV-degradable dye. The screen module 11 is rectangular, and the UV-degradable dye is distributed in a 9-point pattern, which are respectively set at the four corners, the midpoints of the four sides of the rectangle, and the center of the rectangle. There is no special limit on the dosage of the UV-degradable dye in this application. As long as a light color can be seen with a white screen as the background after the screen is lit, it should not be densely piled up.

[0037] After setting the UV-degradable dye in this application, the OCA optical adhesive is coated. In this application, the OCA optical adhesive is a UV-curable adhesive, and the UV energy required for its curing is the same as the UV energy required for the degradation of the UV-degradable dye. Specifically, the UV energy required for the degradation of the UV-degradable dye is within the range of the UV energy required for the curing of the OCA optical adhesive. For example, when the OCA curing energy requirement is 3400 - 4000 mJ / cm², the UV-degradable dye needs to decompose and fade when absorbing energy of 3400 mJ / cm² and above.

[0038] After coating the OCA optical adhesive, a cover plate is set on its surface, and a UV light source is applied for curing. Refer to Figure 2 , Figure 2 which is a schematic flowchart of the curing method provided by the embodiment of this application. Among them, 11 is the screen module, 12 is the UV-degradable dye, 13 is the OCA optical adhesive, and 14 is the cover plate. During the curing process, when the UV-degradable dye degrades into a colorless substance, it can be considered that the energy of the UV light source also meets the energy for curing the OCA optical adhesive. During this process, by checking the remaining situation of the UV-degradable dye, it can be directly determined whether the curing energy of this piece of OCA meets the standard, without the need to separately add additional processes for inspection. Moreover, it is possible to 100% obtain whether the actual energy obtained by the OCA of each product meets the standard, without cumbersome processes and time waiting, and without disassembling the product and wasting materials. In this application, a UV light source can be applied on one side of the cover plate, and the UV-degradable dye is located under the OCA optical adhesive, which can ensure that the UV energy obtained by the OCA optical adhesive is higher than that of the UV-degradable dye. Therefore, using the UV-degradable dye as an indicator, the result is more accurate.

[0039] In the method disclosed in this application, the OCA optical adhesive is a UV-curable adhesive. The fact that the UV energy required for its curing is the same as the UV energy required for the degradation of the UV-degradable dye is the key factor enabling the UV-degradable dye to be used as an indicator. Triphenylmethane dyes are dyes containing highly unsaturated bonds and are easily degraded by UV. By controlling the number of unsaturated bonds, the types and amounts of easily oxidizable groups, the conjugated system, etc., the UV energy required for their degradation can be adjusted. Therefore, a UV-degradable dye with the same energy as that required for the complete curing of the OCA optical adhesive used can be selected according to the energy required for the complete curing of the OCA optical adhesive. Moreover, the degradation products of triphenylmethane dyes after UV irradiation are transparent liquid substances such as benzene, toluene, and xylene, which can be absorbed by the optically clear adhesive (OCA) to a certain extent, and there will be no residue affecting the display effect and appearance effect of the display screen. In some specific implementation manners, the UV-degradable dye is micron-sized, which can further reduce the impact on the display and appearance effects of the display screen.

[0040] Specifically, this application can determine whether the curing energy of the OCA optical adhesive meets the standard according to the color change of the UV-degradable dye. As described above, the UV energy required for the curing of the OCA optical adhesive is the same as the UV energy required for the degradation of the UV-degradable dye, and the UV light source penetrates the OCA optical adhesive and then degrades the UV-degradable dye. When the UV-degradable dye is completely degraded to colorless, the OCA optical adhesive can also be completely cured, indicating that the curing of the OCA optical adhesive meets the requirements; when the UV-degradable dye is not completely degraded to colorless, the curing of the OCA optical adhesive may not meet the requirements, and the energy of the UV light source needs to be increased, so that whether the curing of the OCA optical adhesive meets the standard can be visualized, the curing process of the OCA optical adhesive can be controlled, and the production yield of the product can be improved.

[0041] The OCA optical adhesive curing method provided by this application includes the following steps: after setting a UV-degradable dye on the surface of the first element, applying the OCA optical adhesive, setting a second element on the surface of the OCA optical adhesive, and applying a UV light source for curing; the UV energy required for the degradation of the UV-degradable dye is the same as the UV energy required for the curing of the OCA optical adhesive. In this application, before applying the OCA optical adhesive, a UV-degradable dye whose required UV energy for degradation is the same as the UV energy required for the curing of the OCA optical adhesive (that is, the UV energy required for the degradation of the UV-degradable dye is within the range of the UV energy required for the curing of the OCA optical adhesive) is first set on the surface of the first element, and then a UV light source is applied for curing. During the curing process, it can be determined whether the curing of the OCA optical adhesive meets the standard according to the color degradation of the UV-degradable dye. For example, if the UV-degradable dye is completely degraded, it proves that the energy of the applied UC light source is also sufficient to make the curing of the OCA optical adhesive meet the standard. Therefore, the curing method provided by this application can visually detect whether the curing energy of the OCA optical adhesive meets the standard, without the need for separate detection during the curing process, without adding processes, and without disassembling and wasting materials.

[0042] Furthermore, the degradation products of the UV-degraded dye are transparent liquid substances, such as benzene, toluene, xylene, etc., which can be absorbed by the OCA optical adhesive, so that there is no material residue and it will not affect the prepared components, such as the appearance and display effects of the screen.

[0043] The difference between the second embodiment and the first embodiment of this application is that instead of setting the UV-degraded dye on the surface of the first component, an aggregation-induced emission material is set, and the online judgment of the UV energy required for curing the OCA optical adhesive is realized by using the luminescence performance of the aggregation-induced emission material.

[0044] This application takes the display screen as an example to illustrate the second embodiment of the OCA optical adhesive curing method, that is, the first component is a screen module and the second component is a cover plate. Those skilled in the art can understand that the method provided in this application is not limited to the display screen, and any electronic device that needs to use the OCA optical adhesive can refer to the method disclosed in this application.

[0045] This application first sets an aggregation-induced emission material (AEI) on the surface of the screen module. This application has no special restrictions on the aggregation-induced emission material, as long as the intramolecular motion can be restricted and fluorescence can be emitted when irradiated with UV after the OCA is cured and crosslinked. In one implementation of this application, the aggregation-induced emission material is arranged in a dot pattern, that is, the aggregation-induced emission material is arranged at different positions on the surface of the screen module. Specifically, the aggregation-induced emission material is arranged at the corners and the center position of the first component, and can be planned according to the actual size of the screen module. See Figure 3 , Figure 3 is a schematic diagram of the arrangement of the aggregation-induced emission material in the embodiment of this application. Among them, 31 is the screen module and 32 is the aggregation-induced emission material. The screen module 31 is rectangular, and the aggregation-induced emission material is distributed in a 9-point pattern, and is respectively arranged at the four corners, the midpoints of the four sides and the center of the rectangle. This application has no special restrictions on the dosage of the aggregation-induced emission material, and it cannot be densely packed.

[0046] After this application sets the aggregation-induced emission material, the OCA optical adhesive is coated. After the OCA optical adhesive is coated, a cover plate is set on its surface, and a UV light source is applied for curing. In this application, the OCA optical adhesive is a UV-curable adhesive, and the UV energy required for its curing can restrict the aggregation-induced emission material and emit specific fluorescence, such as a specific fluorescence intensity, fluorescence spectrum or fluorescence brightness, etc., so as to determine the UV energy required for curing the OCA optical adhesive according to the luminescence performance of the aggregation-induced emission material.

[0047] Specifically, in the present application, a standard curve of the luminescence performance of the aggregation-induced emission material and the UV energy is established in advance. When curing is performed by applying a UV light source, the luminescence performance of the aggregation-induced emission material is monitored, and the curing is stopped when it is consistent with the UV energy required for curing the OCA optical adhesive.

[0048] In some specific implementation manners, the standard curve of the luminescence performance and the UV energy is established according to the following method:

[0049] The aggregation-induced emission material is treated with a gradient UV energy, and the luminescence performance of the aggregation-induced emission material under different UV energies is obtained respectively;

[0050] A standard curve is established with the UV energy as the first coordinate and the luminescence performance of the aggregation-induced emission material as the second coordinate.

[0051] Those skilled in the art can understand that the standard curve of the luminescence performance and the UV energy can be established according to the specific aggregation-induced emission material and the OCA curing agent, and the establishment conditions are the same as the curing conditions to ensure the correspondence between the luminescence performance and the UV energy. For example, when the OCA curing energy requirement is 3400 - 4000 mJ / cm 2 , when establishing the standard curve of the luminescence performance and the UV energy, the gradient UV energy preferably covers the above curing energy, so as to ensure the linear relationship between the luminescence performance and the UV energy.

[0052] In a specific implementation manner, the fluorescence intensities of the aggregation-induced emission material can be detected at 1000 mJ / cm 2 , 1500 mJ / cm 2 , 2000 mJ / cm 2 , 2500 mJ / cm 2 , 3000 mJ / cm 2 , 3500 mJ / cm 2 , 4000 mJ / cm 2 , 4500 mJ / cm 2 and other UV energies respectively. Then, a standard curve is established with the UV energy as the abscissa and the corresponding fluorescence intensity as the ordinate. During the actual curing process, the fluorescence intensity of the aggregation-induced emission material is detected by a fluorescence detector and compared with the standard curve. When the actually detected fluorescence intensity is consistent with the fluorescence intensity corresponding to the UV energy actually required for curing the OCA adhesive in the standard curve, it indicates that the curing end point has been reached and the curing can be stopped.

[0053] In this application, an aggregation-induced emission material is disposed on the surface of the first component. After the OCA is cured and crosslinked, the intramolecular motion of the AIE is restricted, resulting in the AIE emitting fluorescence under UV irradiation. By detecting the fluorescence emission performance of the AIE material, it is possible to online determine whether the curing energy of the OCA optical adhesive meets the standard. During the curing process, there is no need for separate detection, no need to add processes, and no need to disassemble and waste materials. Moreover, the method provided in this application can reduce the occurrence of the phenomenon that the curing energy of the OCA optical adhesive does not meet the standard and improve the product yield rate.

[0054] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An OCA optical adhesive curing method, characterized in that, It includes the following steps: After setting a UV-degradable dye or an aggregation-induced emission material on the surface of the first element, coat an OCA optical adhesive, set the second element on the surface of the OCA optical adhesive, and apply a UV light source for curing; The UV energy required for the degradation of the UV-degradable dye is consistent with the UV energy required for the curing of the OCA optical adhesive; Alternatively, determine the UV energy required for the curing of the OCA optical adhesive according to the luminescence properties of the aggregation-induced emission material, and the luminescence properties of the aggregation-induced emission material include one or more of fluorescence spectrum, fluorescence intensity, or fluorescence brightness.

2. The curing method according to claim 1, wherein The first element is a screen module, and the second element is a cover plate.

3. The curing method according to claim 2, characterized in that, Set a UV-degradable dye on the surface of the first element, and the UV-degradable dye is arranged in dots.

4. The curing method according to claim 3, wherein, The UV-degradable dye is set at the corners and the center of the first element.

5. The curing method according to any one of claims 1 to 4, characterized in that, The UV-degradable dye is micron-sized.

6. The curing method according to claim 5, wherein The UV-degradable dye is a triphenylmethane dye.

7. The curing method according to claim 2, wherein Set an aggregation-induced emission material on the surface of the first element; Pre-establish a standard curve of the luminescence properties of the aggregation-induced emission material and the UV energy. When applying a UV light source for curing, monitor the luminescence properties of the aggregation-induced emission material, and stop curing when it is consistent with the UV energy required for the curing of the OCA optical adhesive.

8. The curing method according to claim 7, wherein The standard curve of the luminescence properties and the UV energy is one or more of the standard curve of the fluorescence spectrum and the UV energy, the standard curve of the fluorescence intensity and the UV energy, or the standard curve of the fluorescence brightness and the UV energy.

9. The curing method according to claim 8, wherein, The standard curve of the luminescence properties and the UV energy is established according to the following method: Treat the aggregation-induced emission material with a gradient UV energy to obtain the luminescence properties of the aggregation-induced emission material under different UV energies respectively; Establish a standard curve with the UV energy as the first coordinate and the luminescence properties of the aggregation-induced emission material as the second coordinate.

10. The curing method according to claim 9, characterized in that, The luminescence property is the fluorescence intensity.

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