High-temperature-aging-resistant electronic adhesive tape and preparation method thereof

Abstract

The invention discloses a high-temperature-aging-resistant electronic adhesive tape as well as a preparation method and application thereof, and aims to solve the technical problem that the high temperature resistance and adhesion stability of the conventional electronic adhesive tape are unbalanced. The electronic adhesive tape is prepared by taking modified polyimide as a base material and matching with a special glue solution through coating, drying and curing, the modified polyimide base material is prepared by ultraviolet ozone activation, silanization treatment and silica sol coating compounding, and the glue solution is prepared by compounding organic silicon modified acrylate resin, a compound fluorinated modifier, nano aluminum oxide, a cross-linking agent and a mixed solvent. The electronic adhesive tape has the advantages of high heat resistance limit, lasting adhesion at high temperature, excellent peel strength and no adhesive residue after high-temperature aging, good mechanical property and insulativity, and can be widely applied to insulation, fixation and protection of electronic and electrical equipment and electronic components.

Description

Technical Field

[0001] This invention belongs to the field of electronic materials technology, specifically relating to a high-temperature aging resistant electronic tape and its preparation method. Background Technology

[0002] With the miniaturization and high power density of electronic and electrical equipment, and the rise of new energy vehicles and energy storage systems, the heat generated by electronic components and modules during operation has increased significantly, placing higher demands on the high-temperature resistance of the insulation, fixing, and protective materials used in the surrounding environment. As a key auxiliary material, electronic tape needs to maintain stable adhesion, mechanical strength, and insulation properties over a long period of time in high-temperature environments, without becoming brittle, melting, delaminating, or experiencing a sharp decline in performance.

[0003] Currently, most commercially available high-temperature resistant electronic tapes use polyimide film or polyester film as the base material, combined with acrylic or silicone pressure-sensitive adhesives. However, the dimensional stability and mechanical properties of ordinary polyimide film will slowly decline in long-term environments above 150°C; while PET film has a lower upper limit for temperature resistance. Traditional acrylic pressure-sensitive adhesives have limited heat resistance and are prone to softening and becoming sticky or oxidatively crosslinking and brittle at high temperatures; silicone pressure-sensitive adhesives, although having good heat resistance, often have low initial tack and peel strength, poor adhesion to certain substrates, and are also more expensive.

[0004] Therefore, developing an electronic tape that combines excellent substrate heat resistance, high-reliability adhesive system, and good overall performance is of great significance for meeting the needs of high-end electronic manufacturing and harsh operating conditions. Summary of the Invention

[0005] In response to the stringent requirements for electronic tapes on the market, the purpose of this invention is to provide an electronic tape that combines excellent heat resistance of the substrate, a highly reliable adhesive system, and good overall performance to meet the needs of high-end electronic manufacturing and harsh working conditions.

[0006] To achieve the above objectives, the present invention discloses the following technical solutions: In a first aspect, the present invention provides a method for preparing a high-temperature aging resistant electronic tape, the method comprising the following steps: The adhesive is applied to the modified polyimide substrate, dried and cured, with the dry adhesive layer thickness controlled at 15±1μm. Release paper is then applied to the dry adhesive surface, and the tape is wound up and cut to obtain the electronic tape. The adhesive solution is prepared by the following method: Organosilicon-modified acrylate resin, fluorinated modifier, nano-alumina, triglycidyl isocyanurate, catalyst and mixed solvent are added to a container, mixed and stirred evenly, and filtered to obtain a gel solution. The modified polyimide substrate is prepared by the following method: Step 1: Perform ultraviolet ozone surface treatment on the polyimide film, then immerse it in a 1% γ-(2,3-epoxypropoxy)propyltrimethoxysilane ethanol solution, remove it and bake it at 120℃ for 10 min to obtain silanized polyimide film. Step 2: Mix tetraethyl orthosilicate, anhydrous ethanol and deionized water in a molar ratio of 1:4:3, add hydrochloric acid to adjust the pH to 3, and stir at room temperature for 2-4 hours to obtain silica sol; Step 3: Coat the surface of the silanized polyimide film with silica sol evenly, and then dry it at 80-120℃ for 3-5 minutes to obtain a coating with a dry film thickness of 100-200nm, which is the modified polyimide substrate.

[0007] Preferably, the mass proportions of each raw material in the adhesive solution are as follows: 100-120 parts of organosilicon-modified acrylate resin; 12-20 parts of triglycidyl isocyanurate; 10-15 parts of fluorinated modifier; 8-13 parts of nano-alumina; 0.5-2 parts of 2-methylimidazole; Mixed solvent 150-180 parts.

[0008] More preferably, the fluorinated modifier is obtained by compounding trifluoroethyl methacrylate and perfluoropolyether acrylate in a mass ratio of 1:1.

[0009] More preferably, the mixed solvent is obtained by compounding propylene glycol methyl ether acetate and cyclohexanone in a volume ratio of 1:1.

[0010] More preferably, the nano-alumina is obtained by surface treatment with silane coupling agent KH-570, and the average particle size of the nano-alumina is 30 nm.

[0011] Secondly, the present invention provides an electronic tape resistant to high temperature aging, wherein the electronic tape is prepared by the preparation method described in the first aspect.

[0012] Thirdly, the present invention provides the application of the high-temperature aging resistant electronic tape described in the second aspect in electronic and electrical equipment.

[0013] Fourthly, the present invention provides the application of the high-temperature aging resistant electronic tape described in the second aspect on electronic components.

[0014] The beneficial effects of this invention are: 1. The electronic tape provided by this invention has a high heat resistance limit, excellent high-temperature holding power, high peel strength retention rate after high-temperature aging, and no adhesive residue. It can maintain stable bonding performance, mechanical strength and insulation in high-temperature environments for a long time, meeting the stringent working conditions of high-end electronic manufacturing and new energy fields.

[0015] 2. The preparation process provided by this invention is simple and controllable, the raw materials are easy to obtain, and the cost is more competitive than that of pure organosilicon systems. It does not require special production equipment, which facilitates large-scale production and application, and is suitable for the development trend of miniaturization and high power density in the electronics industry. Detailed Implementation

[0016] To better illustrate the objectives, technical solutions, and advantages of this invention, the invention will be further described below with reference to specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0017] Unless otherwise specified, the test methods used in the examples and comparative examples are conventional methods; the materials and reagents used are commercially available unless otherwise specified; and the percentages mentioned in the examples and comparative examples are mass percentages unless otherwise specified.

[0018] In this invention Organosilicon modified acrylate resin: model RB-237, purchased from Xinuo New Materials; Nano-alumina: 30nm particle size, purchased from Deco Island Gold Technology; The method for treating nano-alumina with silane coupling agent KH-570 is as follows: Step 1: Take nano alumina powder, place it in an oven at 110-120℃ and dry it for 2-3 hours to remove the moisture adsorbed on the surface of the powder, and then cool it to room temperature for later use. Step 2: Weigh 3% of the silane coupling agent KH-570 by mass of nano alumina, dilute with anhydrous ethanol to prepare a 5% KH-570 ethanol solution, add glacial acetic acid to adjust the pH of the system to 4-5, stir at room temperature for 30 min to allow KH-570 to be fully hydrolyzed to generate silanol groups. Step 3: Add the nano-alumina powder to the above hydrolysate, place it in a constant temperature water bath at 60-70℃, and stir at 800-1000 r / min for 2 hours. After the reaction is completed, filter the mixture, wash it 2-3 times with anhydrous ethanol, and then dry it in an oven at 110℃ for 4 hours. After cooling, pulverize it at high speed to obtain nano-alumina surface treated with silane coupling agent KH-570.

[0019] Other raw materials used are commercially available.

[0020] Example 1 1. Substrate pretreatment Step 1: First, treat the polyimide film with UV ozone cleaner for 5 minutes to activate the surface, then immerse it in 1% γ-(2,3-epoxypropoxy)propyltrimethoxysilane ethanol solution, take it out and bake it at 120℃ for 10 minutes to complete the silane coupling agent grafting. Step 2: Mix tetraethyl orthosilicate, anhydrous ethanol and deionized water in a molar ratio of 1:4:3, add hydrochloric acid to adjust the pH to 3, and stir at room temperature for 2-4 hours to allow it to fully hydrolyze and prepolymerize, forming a stable and transparent silica sol. Step 3: Coat the above sol evenly onto the surface of the polyimide film treated with silane. Immediately place the coated film in a hot air circulating oven at 80-120℃ for 3-5 minutes. During this process, the sol quickly gels and dries, forming a dense, transparent and firm nano-silica composite coating on the polyimide surface. The dry film thickness is 100-200nm, thus obtaining the modified polyimide substrate.

[0021] 2. Preparation of adhesive solution (1) Prepare the following materials by weight: 100 parts of silicone-modified acrylate resin, 12 parts of heat-resistant crosslinking agent triglycidyl isocyanate (TGIC), 15 parts of fluorinated modifier (trifluoroethyl methacrylate: perfluoropolyether acrylate = 1:1 w / w), 8 parts of nano alumina treated with silane coupling agent KH-570, 0.5 parts of catalyst 2-methylimidazole, and 150 parts of mixed solvent (propylene glycol methyl ether acetate: cyclohexanone = 1:1 v / v).

[0022] (2) The specific preparation method of the adhesive solution is as follows: Step 1: According to the dosage in (1), add the organosilicon-modified acrylate resin, fluorinated modifier, nano alumina and 60% of the total mixed solvent to the dispersion tank and disperse at 1500 r / min for 30 min. Step 2: Then, the triglycidyl isocyanurate and the catalyst are pre-dissolved in a mixed solvent (20% of the total solvent), then added to a dispersion tank, and finally the remaining mixed solvent (20% of the total solvent) is added. The mixture is stirred at 500 r / min for 20 min, filtered, and the gel solution is obtained.

[0023] 3. Preparation of electronic tape The above-mentioned adhesive solution is applied to the modified polyimide substrate, the wet adhesive thickness is controlled, and it is placed in a hot air circulating oven at 80-100℃ for curing time of about 2-4 minutes. During this process, the solvent evaporates, and the thermal initiator decomposes to initiate a cross-linking reaction. The dry adhesive layer thickness is controlled at 15±1μm. Release paper is applied to the dry adhesive surface, and the tape is wound up and cut to obtain electronic tape.

[0024] Example 2 Referring to the preparation method of Example 1, the difference lies in the raw materials in "2. Preparation of Adhesive Solution" being adjusted to: 110 parts of organosilicon modified acrylate resin, 15 parts of heat-resistant crosslinking agent triglycidyl isocyanate (TGIC), 13 parts of fluorinated modifier (trifluoroethyl methacrylate: perfluoropolyether acrylate = 1:1 w / w), 10 parts of nano-alumina treated with silane coupling agent KH-570, 1 part of catalyst 2-methylimidazole, and 170 parts of mixed solvent (propylene glycol methyl ether acetate: cyclohexanone = 1:1 v / v), finally obtaining the electronic tape of Example 2; Example 3

[0025] Referring to the preparation method of Example 1, the difference lies in the raw materials adjusted in step "2, preparation of adhesive solution": 120 parts of organosilicon modified acrylate resin, 20 parts of heat-resistant crosslinking agent triglycidyl isocyanate (TGIC), 10 parts of fluorinated modifier (trifluoroethyl methacrylate: perfluoropolyether acrylate = 1:1 w / w), 13 parts of nano-alumina treated with silane coupling agent KH-570, 2 parts of catalyst 2-methylimidazole, and 180 parts of mixed solvent (propylene glycol methyl ether acetate: cyclohexanone = 1:1 v / v), finally obtaining the electronic tape of Example 3; Comparative Example 1 The preparation method is the same as in Example 1, except that the polyimide substrate is not pretreated and the adhesive is directly coated onto the untreated polyimide film. The remaining steps and raw material amounts are the same as in Example 1. Comparative Example 2 The preparation method is the same as in Example 1, except that in step "1. Substrate pretreatment", ultraviolet ozone surface activation treatment is not performed, and subsequent steps are carried out directly. The subsequent steps and raw material amounts are the same as in Example 1. Comparative Example 3 Replace step "1. Substrate pretreatment" with the following method: Oily nano-silica particles with an average particle size of 20 nm were dispersed at high speed in an organopolysilazane (IOTA9283, Ayota Corporation) at an addition amount of 10 wt% to obtain a composite coating. The coating was uniformly coated on the surface of a polyimide film and cured at 130 °C for 30 min under nitrogen protection to form a hybrid coating with a thickness of about 200 nm, thus obtaining a modified polyimide substrate ①. The subsequent steps and raw materials are the same as in Example 1; Comparative Example 4 The preparation method is the same as in Example 1, except that the organosilicon-modified acrylate resin in step "2, preparation of adhesive solution" is replaced with ordinary acrylate resin, and the rest of the steps and raw materials are the same as in Example 1. Comparative Example 5 The preparation method is the same as in Example 1, except that the fluorinated modifier in step "2, preparation of adhesive solution" is composed of trifluoroethyl methacrylate alone, while the other steps and raw materials are the same as in Example 1. Comparative Example 6 The preparation method is the same as in Example 1, except that the fluorinated modifier in step "2, preparation of adhesive solution" is composed of a single perfluoropolyether acrylate, while the remaining steps and raw materials are the same as in Example 1.

[0026] Performance testing 1. Peel strength: Refer to GB / T 2792-2014, measure the peel strength with stainless steel plate at a peel angle of 180° (unit: N / 25mm). 2. Holding power at room temperature: Refer to GB / T 4851-2014, measure the holding power (unit: h) of a steel plate perpendicular to the standard at room temperature (25℃); 3. High-temperature holding power: Refer to GB / T 4851-2014, measure the holding power (unit: h) of a standard perpendicular steel plate at 150℃, observe once every half hour, and record the drop time; 4. Peel strength after high temperature aging: After aging the sample in a 100℃ oven for 100h, measure the peel strength according to the above-mentioned test method (unit: N / 25mm). 5. High-temperature peeling residue status: After peeling at 150℃, observe the state of residual adhesive on the surface of the adhered object (divided into no adhesive residue, small amount of adhesive residue, and obvious adhesive residue). 6. Heat resistance limit: Gradually increase the temperature until the sample shows obvious deformation and cracking, and record the critical temperature (unit: °C).

[0027] Table 1 Test Results for Each Item Test Project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Peel strength (N / 25mm) 13.2 14.1 12.5 7.8 9.2 11.5 6.5 8.5 9.0 Holding power at room temperature (h) 38 40 37 25 27 32 20 29 31 High-temperature holding power (150℃, h) 7.5 8.0 7.0 2.7 3.1 5.8 1.6 2.9 2.9 Peel strength after high-temperature aging (N / 25mm) 12.8 13.3 11.9 3.6 3.8 9.2 1.2 5.3 5.6 High-temperature peeling residue No residue No residue No residue Obvious adhesive residue Obvious adhesive residue No residue Obvious adhesive residue Small amount of residual glue Small amount of residual glue Heat resistance limit (°C) 185 192 178 165 170 180 140 172 175 Results analysis: Based on the test data, it can be seen that the electronic tapes prepared in Examples 1-3 all exhibit excellent comprehensive performance in core indicators such as peel strength, room temperature / high temperature holding power, stability after high temperature aging, heat resistance limit and residual adhesive control, and the performance of each indicator is balanced.

[0028] Comparative Example 1, without any substrate pretreatment, exhibited a high-temperature holding power of only 2.7 hours and a peel strength reduced to 3.6 N / 25 mm after high-temperature aging, with noticeable adhesive residue. This is because the unactivated polyimide film has strong surface inertness and weak interfacial adhesion with the adhesive, making it prone to interfacial debonding under high-temperature conditions. In contrast, the Example 1, through UV ozone activation, coupling agent grafting, and silica coating pretreatment, improved the surface roughness and number of active groups of the polyimide. Furthermore, a chemical connection bridge between the substrate and the adhesive was constructed through a silane coupling agent. Simultaneously, the nano-silica coating enhanced the surface mechanical strength and heat resistance of the substrate. The synergistic effect of these three factors significantly improved the interfacial adhesion.

[0029] Comparative Example 2, which omitted the UV ozone activation step, showed significantly lower high-temperature tack and peel strength after high-temperature aging compared to Example 1, and also exhibited noticeable adhesive residue. This indicates that UV ozone treatment can effectively break down inert groups on the polyimide surface and introduce active sites such as hydroxyl groups, providing a foundation for subsequent silane coupling agent grafting and nano-silica coating adhesion. The absence of this step directly leads to a decline in interfacial bonding performance.

[0030] Comparative Example 3, employing a coating process combining oleophilic nano-silica with polysilazane, achieved peel strength and heat resistance close to the examples, but its high-temperature holding power was still lower than that of Examples 1-3. This is because the coating formed by the in-situ hydrolysis and gelation of the silica sol in this invention has better compatibility with the polyimide substrate and adhesive, resulting in a denser coating and stronger adhesion. In contrast, the physically dispersed coating of Comparative Example 3 is prone to microcracks at high temperatures, affecting interfacial stability.

[0031] Comparative Example 4 used ordinary acrylate resin instead of silicone-modified acrylate. Its high-temperature holding power was only 1.6 hours, the peel strength after high-temperature aging dropped sharply to 1.2 N / 25 mm, the heat resistance limit was only 140℃, and significant residue was observed. This is because the molecular chain structure of ordinary acrylate resin lacks heat-resistant groups, making it prone to softening and becoming sticky or cross-linking and embrittled at high temperatures. In contrast, the siloxane bonds introduced after silicone modification have excellent thermal stability, effectively suppressing the thermal motion of the molecular chains at high temperatures, while simultaneously improving the compatibility between the adhesive and the substrate.

[0032] The high-temperature tack and peel strength after high-temperature aging of Comparative Example 5 (single trifluoroethyl methacrylate) and Comparative Example 6 (single perfluoropolyether acrylate) were lower than those of Examples 1-3. This indicates that the low surface energy characteristics of trifluoroethyl methacrylate complement the temperature and chemical resistance of perfluoropolyether acrylate. The combination can simultaneously optimize the adhesive's adhesion stability and high-temperature aging resistance, while a single fluorinated modifier cannot meet both of these core requirements.

[0033] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a high-temperature aging resistant electronic tape, characterized in that, The preparation method includes the following steps: The adhesive is applied to the modified polyimide substrate, dried and cured, with the dry adhesive layer thickness controlled at 15±1μm. Release paper is then applied to the dry adhesive surface, and the tape is wound up and cut to obtain the electronic tape. The adhesive solution is prepared by the following method: Organosilicon-modified acrylate resin, fluorinated modifier, nano-alumina, triglycidyl isocyanurate, catalyst and mixed solvent are added to a container, mixed and stirred evenly, and filtered to obtain a gel solution. The modified polyimide substrate is prepared by the following method: Step 1: Perform ultraviolet ozone surface treatment on the polyimide film, then immerse it in a 1% γ-(2,3-epoxypropoxy)propyltrimethoxysilane ethanol solution, remove it and bake it at 120℃ for 10 min to obtain silanized polyimide film. Step 2: Mix tetraethyl orthosilicate, anhydrous ethanol and deionized water in a molar ratio of 1:4:3, add hydrochloric acid to adjust the pH to 3, and stir at room temperature for 2-4 hours to obtain silica sol; Step 3: Coat the surface of the silanized polyimide film with silica sol evenly, and then dry it at 80-120℃ for 3-5 minutes to obtain a coating with a dry film thickness of 100-200nm, which is the modified polyimide substrate.

2. The preparation method according to claim 1, characterized in that, The mass fractions of each raw material in the adhesive solution are as follows: 100-120 parts of organosilicon-modified acrylate resin; 12-20 parts of triglycidyl isocyanurate; 10-15 parts of fluorinated modifier; 8-13 parts of nano-alumina; 0.5-2 parts of 2-methylimidazole; Mixed solvent 150-180 parts.

3. The preparation method according to claim 1 or 2, characterized in that, The fluorinated modifier is obtained by compounding trifluoroethyl methacrylate and perfluoropolyether acrylate in a mass ratio of 1:

1.

4. The preparation method according to claim 1 or 2, characterized in that, The mixed solvent is obtained by compounding propylene glycol methyl ether acetate and cyclohexanone in a volume ratio of 1:

1.

5. The preparation method according to claim 1 or 2, characterized in that, The nano-alumina was obtained by surface treatment with silane coupling agent KH-570, and the average particle size of the nano-alumina was 30 nm.

6. A high-temperature aging resistant electronic tape, characterized in that, The electronic tape is prepared by the preparation method according to any one of claims 1-5.

7. The application of the high-temperature aging resistant electronic tape as described in claim 6 in electronic and electrical equipment.

8. The application of the high-temperature aging resistant electronic tape as described in claim 6 on electronic components.