Packaging adhesive for Mini-LED display module and preparation method thereof

Abstract

The invention relates to the technical field of LED packaging adhesives, in particular to a packaging adhesive for a Mini-LED display module and a preparation method of the packaging adhesive. The packaging adhesive comprises a component A and a component B, wherein the weight ratio of the component A to the component B is 1: (0.8-1); wherein every 100 parts of the component A comprises 35-50 parts of alicyclic epoxy resin, 5-20 parts of hydrogenated bisphenol A type epoxy resin, 25-40 parts of modified silica powder and 1-10 parts of a reactive diluent; the modified silica powder is silica powder modified by a silane coupling agent; every 100 parts of the component B comprises 85-95 parts of anhydride, 1-10 parts of a toughening agent and 0.5-5 parts of a curing accelerator. The packaging adhesive provided by the invention has the advantages of low viscosity and curing stress, and can effectively reduce the probability of occurrence of defects such as inconsistent ink colors and hard spots generated in the packaging process. And a packaging adhesive layer obtained by curing the packaging adhesive has the advantages of high transparency, heat resistance, moisture resistance and ultraviolet resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of LED encapsulation adhesives, and particularly to an encapsulation adhesive for a Mini-LED display module and a preparation method thereof. Background Art

[0002] Mini-LED refers to chips with a size in the range of 50-200 μm, which is less than 20% of the size of traditional LED chips. Compared with traditional LEDs, Mini-LED has more stringent requirements for encapsulation materials. Mini-LED encapsulation materials should not only have excellent optical properties, but also good heat resistance, radiation resistance and mechanical properties to provide sufficient protection for the device while ensuring light output and improving the service life of the device. Common Mini-LED encapsulation adhesives include epoxy resins and silicone rubbers. Epoxy resins have advantages such as high light transmittance, good bonding performance and strong airtightness, but their weather resistance is relatively poor and the stress is relatively high. Although silicone rubbers have strong weather resistance, their adhesiveness is poor, so they are not widely used at present. Currently, epoxy resins are still widely used.

[0003] To solve the internal stress problem of epoxy resin adhesives, a common approach is to introduce a toughening agent into the encapsulation adhesive. For example, in the prior art, a flexible polymer molecular chain containing -NH and -OH in the side chain is introduced, so that it has a bonding effect with the epoxy resin molecular chain. Thus, the toughening agent molecular chain inserts between the epoxy resin molecular chains, improving the slipperiness of the epoxy resin molecular chains, and then playing a role in toughening modification and plasticization, which can effectively reduce the internal stress of the epoxy resin. However, this technical solution requires a complex process to synthesize the toughening agent, and this toughening agent will reduce the curing speed and significantly reduce the production efficiency. Another common approach is to introduce fillers. For example, a prior art provides a low-warpage and low-viscosity liquid encapsulation adhesive, which includes the following components in parts by weight: 80-90 parts of a filler, 1.5-4.5 parts of a first epoxy resin, 10-15 parts of a mixture, 1-3 parts of a curing agent, 0.2-0.5 parts of an accelerator, and 0.1-0.3 parts of a dye; wherein, the mixture is composed of a second epoxy resin and silica powder. By introducing silica powder, the stress can be reduced and the encapsulation warpage can be reduced. However, the introduction of silica powder increases the viscosity of the encapsulation adhesive and deteriorates the fluidity, which will not only reduce the encapsulation production efficiency, but also, since the encapsulation adhesive needs to flow into the gap between the PCB substrate and the Mini-LED chip, if the viscosity is too high, it is often difficult to fully cover this area, easily resulting in encapsulation quality problems such as inconsistent ink color and pitting. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a packaging adhesive for a Mini-LED display module, which has low internal stress and low viscosity, and can reduce the probability of ink color inconsistency and pitting defects. Moreover, the packaging adhesive layer obtained by curing the packaging adhesive has the advantages of high transparency, heat resistance, moisture resistance, and ultraviolet resistance.

[0005] Another technical problem to be solved by the present invention is to provide a preparation method for a packaging adhesive for a Mini-LED display module.

[0006] To solve the above technical problems, the present invention provides a packaging adhesive for a Mini-LED display module, which comprises component A and component B, and the weight ratio of component A to component B is 1:(0.8 - 1);

[0007] Among them, every 100 parts of component A includes: 35 - 50 parts of alicyclic epoxy resin, 5 - 20 parts of hydrogenated bisphenol A epoxy resin, 25 - 40 parts of modified silica powder, and 1 - 10 parts of reactive diluent; the modified silica powder is silica powder modified by a silane coupling agent;

[0008] Every 100 parts of component B includes: 85 - 95 parts of acid anhydride, 1 - 10 parts of toughening agent, and 0.5 - 5 parts of curing accelerator.

[0009] In this technical solution, alicyclic epoxy resin and hydrogenated bisphenol A epoxy resin are used as the main resins. Hydrogenated bisphenol A epoxy resin can effectively improve the toughness of the packaging adhesive layer, reduce its curing shrinkage, and reduce stress. Alicyclic epoxy resin has the advantages of high epoxy equivalent, low viscosity, and small shrinkage, which can optimize the heat resistance of the packaging adhesive and reduce stress. Through the compounding of the two, the stress of the packaging adhesive can be significantly reduced, and the packaging adhesive has good transparency and yellowing resistance. Moreover, the dosage of silica powder is reduced, avoiding the full coverage of the PCB substrate due to the increase in viscosity of silica powder, and reducing the occurrence probability of defects such as ink color inconsistency and pitting. Further, by using a silane coupling agent to modify the silica powder, its compatibility with the main resin is effectively improved. Generally speaking, the packaging adhesive based on this technical solution not only rarely produces packaging defects and ink color inconsistency defects during the packaging process, but also the packaging adhesive layer obtained by curing has the advantages of high transparency, heat resistance, moisture resistance, and ultraviolet resistance.

[0010] Specifically, the structural formula of the alicyclic epoxy resin is as follows:

[0011]

[0012] Among them, n1 ≤ 2, n2 ≥ 1. Such alicyclic groups can better improve thermal stability, light transmittance, and maintain a reasonable viscosity range, and can significantly reduce the probability of defects such as inconsistent ink color and pitting, especially compared with commonly used bisphenol A epoxy resin and bisphenol F epoxy resin.

[0013] Preferably, in some embodiments, the alicyclic epoxy resin is selected from 3,4-epoxy-6-methylcyclohexyl methyl 3',4'-epoxy-6'-methylcyclohexanecarboxylate or bis(3,4-epoxy-6-methylcyclohexyl methyl) adipate, but not limited thereto.

[0014] Exemplarily, the amount of the alicyclic epoxy resin in component A is 37 parts, 39 parts, 41 parts, 43 parts, 45 parts, 47 parts, or 49 parts, but not limited thereto.

[0015] Specifically, the hydrogenated bisphenol A epoxy resin is an epoxy resin without double bonds in its molecule, and its basic structural formula is as follows:

[0016]

[0017] Among them, n3 ≥ 1. This hydrogenated bisphenol A epoxy resin has good mechanical properties after curing, and its thermal stability and weather resistance are superior to those of bisphenol A epoxy resin.

[0018] Preferably, in some embodiments, the epoxy value of the hydrogenated bisphenol A epoxy resin ≥ 0.45 mol / 100 g, and its viscosity at 25°C ≤ 6000 mPa·s; this hydrogenated bisphenol A epoxy resin can better improve the thermal stability and weather resistance of the encapsulant, and its curing time is relatively short, without affecting the encapsulation efficiency.

[0019] Exemplarily, the amount of the hydrogenated bisphenol A epoxy resin in component A is 6 parts, 8 parts, 10 parts, 12 parts, 14 parts, 16 parts, or 18 parts, but not limited thereto.

[0020] Specifically, the modified silica powder is silica powder modified by a silane coupling agent. Through modification, the compatibility between the silica powder and the main resin can be optimized. Specifically, the amount of the modified silica powder in component A is 25 - 40 parts, and the amount of the modified silica powder in this technical solution is relatively low. Exemplarily, it is 27 parts, 29 parts, 31 parts, 33 parts, 35 parts, 37 parts, or 39 parts, but not limited thereto.

[0021] Specifically, the active diluent is selected from one or more of allyl glycidyl ether, phenyl glycidyl ether, and p-isobutylphenyl glycidyl ether, but not limited thereto. Exemplarily, the amount of the active diluent in component A is 3 parts, 4.5 parts, 6 parts, 7.5 parts, or 9 parts, but not limited thereto.

[0022] Specifically, the anhydride in component B is selected from one or more of hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methyltetrahydrophthalic anhydride, but is not limited thereto. The amount of the anhydride in component B is exemplarily 86 parts, 88 parts, 90 parts, 92 parts, or 94 parts, but is not limited thereto.

[0023] Specifically, the toughening agent in component B is selected from styrene-butadiene rubber and / or nitrile rubber, but is not limited thereto. The amount of the toughening agent in component B is 1.5 parts, 3 parts, 4.5 parts, 6 parts, 7.5 parts, or 9 parts, but is not limited thereto.

[0024] Specifically, the curing accelerator in component B can be selected from triethylamine, 2-ethyl-4-methylimidazole, or benzyltriethylammonium chloride, but is not limited thereto. The amount of the curing accelerator in component B is exemplarily 0.8 parts, 1.3 parts, 1.8 parts, 2.3 parts, 2.8 parts, 3.3 parts, 3.8 parts, 4.3 parts, or 4.8 parts, but is not limited thereto.

[0025] Preferably, in some embodiments, the preparation method of the modified silica powder is as follows:

[0026] Mix the silane coupling agent, water, and ethanol, and adjust the pH to 3 - 5. React at 20 - 30 °C for 10 - 30 min to obtain a modified solution;

[0027] Mix and grind the modified solution with the silica powder, then perform solid-liquid separation and drying to obtain the modified silica powder;

[0028] Among them, the silane coupling agent is a methoxysilane coupling agent or an ethoxysilane coupling agent, and it is in a liquid state at room temperature. The volume ratio of the silane coupling agent, the water, and the ethanol is 1:(0.5 - 1.5):(1 - 2); exemplarily 1:0.8:1.1, 1:1:1.3, 1:1.3:1.5, 1:1.3:1.7, or 1:1.4:1.9, but is not limited thereto

[0029] The dosage ratio of the modified solution to the silica powder is 100 mL:(5 - 15) g, exemplarily 100 mL:6 g, 100 mL:8 g, 100 mL:10 g, 100 mL:12 g, or 100 mL:14 g, but is not limited thereto. It should be noted that the unit of the dosage ratio of the modified solution to the silica powder in this technical solution can be a relationship obtained by equal proportion amplification or reduction such as L:kg, m 3 :t or μL:mg, but is not limited thereto.

[0030] In the above-described embodiments, the silane coupling agent is first hydrolyzed to form a large number of silanol (Si-OH) groups, which can better connect with the hydroxyl groups on the surface of the silica powder to form hydrogen bonds or chemical bonds, acting as a molecular bridge, further improving the compatibility of the silica powder in the resin system and reducing the interfacial stress. At the same time, after hydrolysis, the main bonds attached to the surface of the silica powder are Si-O bonds and Si-Si bonds, which can effectively avoid reacting with the epoxy groups in the epoxy resin and prevent the consumption of epoxy groups from causing a decrease in adhesion.

[0031] More preferably, the silane coupling agent is selected from γ-(2,3-epoxypropoxy)propyltrimethoxysilane and 3-aminopropyltriethoxysilane, and the weight ratio of γ-(2,3-epoxypropoxy)propyltrimethoxysilane to 3-aminopropyltriethoxysilane is (2-5):1. By using silane coupling agents with different end groups to modify the silica powder, its dispersibility can be further improved, the usage amount of the modified silica powder can be reduced, and it can effectively reduce stress and avoid warping of the PCB substrate.

[0032] Preferably, in some embodiments, the silica powder is spherical silica powder with an average particle size of 2-10 μm. The spherical silica powder has better fluidity, can be better modified, and can also reduce the viscosity of the encapsulant.

[0033] Preferably, in some embodiments, the B component further includes some common additives in the art, such as defoamers, dispersants, antioxidants, leveling agents, etc., but not limited thereto.

[0034] Preferably, the viscosity of the A component obtained based on the above formula at 25°C is 6000-10000 cps, the viscosity of the B component at 25°C is 300-900 cps, and the viscosity after mixing the two is 3000-5000 cps, which has good fluidity, defoaming property and operability.

[0035] Correspondingly, the present invention also discloses a preparation method of an encapsulant for a Mini-LED display module, which is used to prepare the above encapsulant, and includes:

[0036] Mix the alicyclic epoxy resin, hydrogenated bisphenol A epoxy resin, and active diluent, then add the modified silica powder, stir and disperse, and then defoam to obtain the A component;

[0037] Mix the anhydride, toughening agent, and curing accelerator evenly to obtain the B component.

[0038] Correspondingly, the present invention also discloses a display module encapsulated by the above encapsulant for a Mini-LED display module.

[0039] Accordingly, the present invention also discloses a display screen, which includes the above-mentioned display module.

[0040] Implementing the present invention has the following beneficial effects:

[0041] The encapsulating adhesive for a Mini-LED display module in an embodiment of the present invention includes component A and component B. Component A includes 35-50 parts of alicyclic epoxy resin, 5-20 parts of hydrogenated bisphenol A epoxy resin, 25-40 parts of modified silica powder, and 1-10 parts of active diluent; the modified silica powder is silica powder modified by a silane coupling agent. In this technical solution, alicyclic epoxy resin and hydrogenated bisphenol A epoxy resin are used as the main resins. Hydrogenated bisphenol A epoxy resin can effectively improve the toughness of the encapsulating adhesive layer, reduce its curing shrinkage, and reduce stress; alicyclic epoxy resin can optimize the heat resistance of the encapsulating adhesive and reduce stress. Through the compounding of the two, the stress of the encapsulating adhesive can be significantly reduced, and the encapsulating adhesive has good yellowing resistance. Also, the amount of silica powder is reduced, avoiding defects such as inconsistent ink color caused by the increase in viscosity of silica powder and ensuring full coverage of the PCB substrate. Further, by using a silane coupling agent to modify the silica powder, the compatibility between it and the main resin is effectively improved. Generally speaking, the encapsulating adhesive based on this technical solution not only rarely produces encapsulation defects such as inconsistent ink color and pitting during the encapsulation process, but also the cured encapsulating adhesive layer has the advantages of high transparency, heat resistance, moisture resistance, and ultraviolet resistance. Detailed implementation manners

[0042] In order to make the purpose, technical solutions and advantages of the present application clearer, the following further describes the present application in detail in conjunction with embodiments.

[0043] To facilitate the understanding of the present invention, the present invention will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or implementation manners described herein. On the contrary, the purpose of providing these embodiments or implementation manners is to make the understanding of the disclosed content of the present invention more thorough and comprehensive.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments or implementation manners and are not intended to limit the present invention. The optional scope of the term "and / or" includes any one of two or more related listed items, as well as any and all combinations of the related listed items. The any and all combinations include any two related listed items, any more related listed items, or all related listed items.

[0045] The following examples are given for the purpose of illustrating various embodiments of the present invention and are not intended to limit in any way. The materials, reagents, etc. used in the following examples can be obtained from commercial sources unless otherwise specified.

[0046] Example 1

[0047] This example provides a packaging adhesive for a Mini-LED display module, which includes component A and component B, and the weight ratio of component A to component B is 1:1.

[0048] Among them, component A includes: 45 parts of alicyclic epoxy resin (3,4-epoxy-6-methylcyclohexyl methyl 3’,4’-epoxy-6’-methylcyclohexyl carboxylate), 18 parts of hydrogenated bisphenol A epoxy resin, 32 parts of modified silica powder, and 5 parts of active diluent (allyl glycidyl ether). Among them, the epoxy value of the hydrogenated bisphenol A epoxy resin is 0.47 mol / 100 g, and its viscosity at 25 °C is 4500 mPa·s. The modified silica powder is a product obtained by mixing γ-(2,3-epoxypropoxy)propyltrimethoxysilane with silica powder. Among them, the silica powder is spherical silica powder with an average particle size of 5.6 μm, and the weight ratio of spherical silica powder to γ-(2,3-epoxypropoxy)propyltrimethoxysilane is 2:1.

[0049] Among them, component B includes:

[0050] 90 parts of anhydride (methyltetrahydrophthalic anhydride), 5 parts of toughening agent (styrene-butadiene rubber), 4 parts of curing accelerator (benzyltriethylammonium chloride), 0.5 part of antioxidant (pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]), 0.3 part of leveling agent (BYK-320), and 0.2 part of defoaming agent (BYK-141).

[0051] The preparation method of the packaging adhesive in this example includes:

[0052] Mix the alicyclic epoxy resin, hydrogenated bisphenol A epoxy resin, and active diluent, then add the modified silica powder, stir and disperse, and then defoam to obtain component A;

[0053] Mix the anhydride, toughening agent, curing accelerator, antioxidant, leveling agent, and defoaming agent evenly to obtain component B.

[0054] Example 2

[0055] This example provides a packaging adhesive for a Mini-LED display module, which includes component A and component B, and the weight ratio of component A to component B is 1:0.8.

[0056] Among them, Component A includes: 48 parts of alicyclic epoxy resin (bis(3,4-epoxy-6-methylcyclohexylmethyl) adipate), 14 parts of hydrogenated bisphenol A epoxy resin, 30 parts of modified silica powder, and 8 parts of reactive diluent (phenyl glycidyl ether). Among them, the epoxy value of the hydrogenated bisphenol A epoxy resin is 0.48 mol / 100 g, and its viscosity at 25 °C is 3600 mPa·s.

[0057] The preparation method of the modified silica powder is as follows:

[0058] (1) Mix the silane coupling agent (γ-(2,3-epoxypropoxy)propyltrimethoxysilane), water, and ethanol according to a volume ratio of 1:1:2, and adjust to 3.5 to obtain a modified solution;

[0059] (2) Mix the modified solution and the silica powder according to a ratio of 100 mL:10 g, grind in a planetary ball mill for 15 min, then perform solid-liquid separation and drying to obtain the modified silica powder. Among them, the silica powder is spherical silica powder with an average particle size of 3.5 μm.

[0060] 91 parts of acid anhydride (hexahydrophthalic anhydride), 4 parts of toughening agent (styrene-butadiene rubber), 3 parts of curing accelerator (benzyltriethylammonium chloride), 0.9 part of antioxidant (pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]), 0.6 part of leveling agent (BYK-320), and 0.5 part of defoaming agent (BYK-141).

[0061] The preparation method of the encapsulation adhesive in this example includes:

[0062] Mix the alicyclic epoxy resin, hydrogenated bisphenol A epoxy resin, and reactive diluent, then add the modified silica powder, stir and disperse, and then defoam to obtain Component A;

[0063] Mix the acid anhydride, toughening agent, curing accelerator, antioxidant, leveling agent, and defoaming agent evenly to obtain Component B.

[0064] Example 3

[0065] This example provides an encapsulation adhesive for a Mini-LED display module, which includes Component A and Component B, and the weight ratio of Component A to Component B is 1:0.8.

[0066] Among them, Component A includes: 48 parts of alicyclic epoxy resin (bis(3,4-epoxy-6-methylcyclohexylmethyl) adipate), 14 parts of hydrogenated bisphenol A epoxy resin, 30 parts of modified silica powder, and 8 parts of reactive diluent (phenyl glycidyl ether). Among them, the epoxy value of the hydrogenated bisphenol A epoxy resin is 0.48 mol / 100 g, and its viscosity at 25 °C is 3600 mPa·s.

[0067] The preparation method of the modified silica powder is as follows:

[0068] (1) Mix the silane coupling agent, water, and ethanol according to a volume ratio of 1:1:2, and adjust to 3.5 to obtain a modified liquid; among them, the silane coupling agent is γ-(2,3-epoxypropoxy)propyltrimethoxysilane and 3-aminopropyltriethoxysilane, and the weight ratio of the two is 3:1;

[0069] (2) Mix the modified liquid and the silica powder according to a ratio of 100 mL:10 g, grind in a planetary ball mill for 15 min, then perform solid-liquid separation and drying to obtain the modified silica powder. Among them, the silica powder is spherical silica powder with an average particle size of 3.5 μm.

[0070] 91 parts of anhydride (hexahydrophthalic anhydride), 4 parts of toughening agent (styrene-butadiene rubber), 3 parts of curing accelerator (benzyltriethylammonium chloride), 0.9 part of antioxidant (pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]), 0.6 part of leveling agent (BYK-320), 0.5 part of defoaming agent (BYK-141).

[0071] The preparation method of the encapsulating adhesive in this example includes:

[0072] Mix the alicyclic epoxy resin, hydrogenated bisphenol A epoxy resin, and active diluent, then add the modified silica powder, stir and disperse, and then defoam to obtain component A;

[0073] Mix the anhydride, toughening agent, curing accelerator, antioxidant, leveling agent, and defoaming agent evenly to obtain component B.

[0074] Comparative Example 1

[0075] This comparative example provides an encapsulating adhesive, and the difference from Example 1 is that: in component A, bisphenol A epoxy resin DER 331 is used instead of the alicyclic epoxy resin. The rest are the same as in Example 1.

[0076] Comparative Example 2

[0077] This comparative example provides an encapsulating adhesive, and the difference from Example 1 is that: in component A, bisphenol A epoxy resin DER 331 is used instead of the hydrogenated bisphenol A epoxy resin. The rest are the same as in Example 1.

[0078] Comparative Example 3

[0079] This comparative example provides an encapsulating adhesive, and the difference from Example 1 is that: in component A, the alicyclic epoxy resin is not included, and the dosage of the hydrogenated bisphenol A epoxy resin is 63 parts. The rest are the same as in Example 1.

[0080] Comparative Example 4

[0081] This comparative example provides a packaging adhesive, which is different from that in Example 1 in that: in Component A, hydrogenated bisphenol A epoxy resin is not included, and the amount of alicyclic epoxy resin is 63 parts. The rest are the same as those in Example 1.

[0082] Comparative Example 5

[0083] This comparative example provides a packaging adhesive, which is different from that in Example 1 in that: in Component A, modified silica powder is not included. The rest are the same as those in Example 1.

[0084] The packaging adhesives in Examples 1 to 3 and Comparative Examples 1 to 4 were tested. The specific test methods are as follows:

[0085] (1) Warpage curvature test: Mix Component A and Component B evenly in proportion, pour them into a 100 mm × 170 mm × 2 mm FR4 PCB board, and the thickness of the glue layer is 0.4 mm; cure at 120 °C for 15 min; cure at 150 °C for 3 h. After thermal shock (-40 °C to 105 °C), place the PCB board on a plane and measure the maximum warpage height. The ratio of the maximum warpage height to the length of the PCB board is taken as the warpage curvature.

[0086] (2) Number of thermal shock resistance cycles: Mix Component A and Component B evenly in proportion, pour them into a 100 mm × 170 mm × 2 mm FR4 PCB board, and the thickness of the glue layer is 0.4 mm; cure at 120 °C for 15 min; cure at 150 °C for 3 h, and perform thermal cycling at -40 °C to 80 °C; The number of times when cracks are visible in the glue layer visually is taken as the number of thermal shock resistance cycles.

[0087] (3) Transmittance test: The packaging adhesive is made into a circular specimen with a thickness of 1 - 2 mm and a diameter of 30 mm using a mold, and after baking and curing, it is measured at room temperature using a UV756CRT ultraviolet-visible spectrophotometer. The scanning range is 300 - 800 nm, and the resolution is 1 nm.

[0088] (3) Pitting and ink color consistency: Package the display module with each packaging adhesive, cure at 120 °C for 15 min, and after curing at 150 °C for 3 h, observe whether there are defects such as pitting and inconsistent ink color. In addition, continue to observe whether the ink color is consistent after lighting for 500 h.

[0089] The test results are shown in the following table:

[0090]

[0091] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc., mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

[0092] Although the embodiments of this application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of this application, and the scope of this application is defined by the claims and their equivalents.

Claims

1. A packaging adhesive for Mini-LED display module, characterized in that: It comprises a component A and a component B, wherein the weight ratio of the component A to the component B is 1:(0.8-1); Wherein, every 100 parts of the A component comprises: 35-50 parts of alicyclic epoxy resin, 5-20 parts of hydrogenated bisphenol A epoxy resin, 25-40 parts of modified silicon micropowder, and 1-10 parts of active diluent; the modified silicon micropowder is silicon micropowder modified by silane coupling agent; Every 100 parts of the B component includes: 85-95 parts of anhydride, 1-10 parts of a toughening agent, and 0.5-5 parts of a curing accelerator.

2. The encapsulation adhesive for Mini-LED display module according to claim 1, characterized in that: The preparation method of the modified silicon micropowder is: Mix the silane coupling agent, water and ethanol, adjust the pH to 3-5, and react at 20-30° C. for 10-30 minutes to obtain a modified solution; The modified liquid and silicon micropowder are mixed and ground, and then the solid-liquid separation and drying are performed to obtain modified silicon micropowder; Wherein, the silane coupling agent is a methoxysilane coupling agent or an ethoxysilane coupling agent, and the volume ratio of the silane coupling agent, the water, and the ethanol is 1:(0.5-1.5):(1-2); The usage ratio of the modified liquid to the silicon micropowder is 100 mL: (5-15) g.

3. The encapsulation adhesive for Mini-LED display module according to claim 2, characterized in that: The silane coupling agent is selected from γ-(2,3-epoxypropoxy)propyltrimethoxysilane and 3-aminopropyltriethoxysilane, and the weight ratio of the γ-(2,3-epoxypropoxy)propyltrimethoxysilane to the 3-aminopropyltriethoxysilane is (2-5):

1.

4. The encapsulation adhesive for Mini-LED display module according to claim 2, characterized in that: The silicon micropowder is spherical silicon micropowder with an average particle size of 2 to 10 μm.

5. The encapsulation adhesive for Mini-LED display module according to claim 1, characterized in that: The epoxy value of the hydrogenated bisphenol A epoxy resin is ≥0.45 mol / 100 g, and the viscosity thereof at 25° C. is ≤6000 mPa·s.

6. The encapsulation adhesive for Mini-LED display module according to claim 1, characterized in that: The alicyclic epoxy resin is selected from 3,4-epoxy-6-methylcyclohexylcarboxylic acid-3',4'-epoxy-6'-methylcyclohexyl methyl ester or di(3,4-epoxy-6-methylcyclohexyl methyl adipate).

7. The encapsulation adhesive for Mini-LED display module according to claim 1, characterized in that: The acid anhydride is selected from one or more of hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride and methyltetrahydrophthalic anhydride; The curing accelerator is selected from triethylamine, 2-ethyl-4-methylimidazole or benzyltriethylammonium chloride; The toughening agent is selected from styrene-butadiene rubber and / or nitrile-butadiene rubber; The active diluent is selected from one or more of allyl glycidyl ether, phenyl glycidyl ether, and p-isobutylphenyl glycidyl ether.

8. The encapsulation adhesive for Mini-LED display module according to claim 1, characterized in that: The B component also includes an auxiliary agent, and the auxiliary agent is selected from one or more of a defoamer, a dispersant, an antioxidant, and a leveling agent.

9. The encapsulation adhesive for Mini-LED display module according to claim 1, characterized in that: The viscosity of the component A at 25° C. is 6000-10000 cps, and the viscosity of the component B at 25° C. is 300-900 cps.

10. A method for preparing a packaging adhesive for a Mini-LED display module, for preparing the packaging adhesive for a Mini-LED display module as claimed in any one of claims 1 to 9, characterized in that: include: The alicyclic epoxy resin, hydrogenated bisphenol A type epoxy resin and active diluent are mixed, and then modified silica powder is added, and the mixture is stirred, dispersed and degassed to obtain component A; The acid anhydride, toughening agent and curing accelerator are mixed evenly to obtain component B.

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