Segmented curing heat-conducting bonding insulation sheet and preparation method thereof

Abstract

The invention relates to the technical field of heat-conducting insulating materials, and discloses a segmented curing heat-conducting bonding insulating sheet and a preparation method thereof. An organosilicon addition system and a peroxide curing system exist in a system of the segmented curing heat-conducting bonding insulating sheet at the same time, and the segmented curing heat-conducting bonding insulating sheet comprises the following components in parts by weight: 5-10 parts of vinyl MQ silicon resin, 0.1-1.0 part of a cross-linking agent, 0.1-0.5 part of a platinum catalyst, 0.01-0.1 part of an inhibitor, 5-10 parts of vinyl raw rubber, 0.25-1 part of a peroxide curing agent, 0.05-0.1 part of an accelerant and 50-85 parts of heat-conducting filler. The segmented curing heat-conducting bonding insulation sheet has a high heat conductivity coefficient and can effectively conduct heat of an electronic element, reduce the working temperature and improve the performance and reliability of equipment; high bonding strength can prevent components from falling off and ensure the stability of equipment; the preparation method is simple, does not need complex equipment and process, and is easy for industrial production.

Description

Technical Field

[0001] The invention relates to the technical field of thermally conductive adhesive materials, and in particular to a segmented curing thermally conductive adhesive insulating sheet and a preparation method thereof. Background Art

[0002] With the continuous development of electronic equipment, the requirements for heat dissipation and insulation performance are getting higher and higher. As an important electronic material, thermal conductive adhesive insulation sheets can effectively conduct the heat generated by electronic components while ensuring electrical insulation between electronic components. At present, thermal conductive adhesive insulation sheets on the market generally have problems with insufficient thermal conductivity and bonding strength, which makes it difficult to meet the needs of high-performance electronic equipment. Summary of the invention

[0003] In view of the above shortcomings of the prior art, the object of the present invention is to provide a segmented curing thermally conductive adhesive insulating sheet and a preparation method thereof.

[0004] To achieve the above objectives, the technical solutions adopted are:

[0005] One of the purposes of the present invention is to provide a segmented curing thermally conductive adhesive insulating sheet, in which a silicone addition system and a peroxide curing system are simultaneously present, and the sheet comprises the following components in parts by weight: 5-10 parts of vinyl MQ silicone resin, 0.1-1.0 parts of a cross-linking agent, 0.1-0.5 parts of a platinum catalyst, 0.01-0.1 parts of an inhibitor, 5-10 parts of vinyl raw rubber, 0.25-1 parts of a peroxide curing agent, 0.05-0.1 parts of an accelerator, and 50-85 parts of a thermally conductive filler.

[0006] Furthermore, the molecular weight of the vinyl MQ silicone resin is 2000-4000, the viscosity is 2000-3000 cps, and the vinyl content is 0.05-0.15 mmol / g.

[0007] Furthermore, the crosslinking agent is a double hydrogen-terminated siloxane with a molecular weight of 200-500, a viscosity of 230-350 cps, and a hydrogen content of 0.5-1.6 mmol / g.

[0008] Furthermore, the platinum catalyst is a chloroplatinic acid platinum complex with a platinum content of 2000 PPM.

[0009] Furthermore, the inhibitor is alkynyl cyclohexanol with a concentration of 0.5%.

[0010] Furthermore, the molecular weight of the vinyl raw rubber is 500,000-600,000.

[0011] Furthermore, the peroxide curing agent is 2,4-di-tert-butyl peroxide isopropylbenzene, and the effective substance content is ≥96%.

[0012] Furthermore, the accelerator is triallyl isocyanurate, and the effective substance content is 99%.

[0013] Furthermore, the thermally conductive filler is a combination of two types of alumina powders with different particle sizes.

[0014] The second purpose of the present invention is to provide a method for preparing the segmented curing thermal conductive adhesive insulating sheet, comprising the following steps: adding vinyl MQ silicone resin, crosslinking agent, platinum catalyst, inhibitor, vinyl raw rubber, peroxide curing agent, and accelerator together into an internal mixer, mixing them evenly at room temperature, and then mixing the rubber with a double-roller mill until the colloid is mixed evenly and does not stick to the rollers to obtain a base material; product molding: selecting a fluoroplastic release film with a peeling force of 3g as the base film and a glass fiber cloth with a basis weight of 25±5g / m2 as the reinforcing material, and rolling the evenly mixed base material into a sheet by a 5-roll step-by-step rolling method. After two rollings, a sheet with glass fiber in the middle and base material covering both sides is initially formed. The entire sheet is placed in a tunnel furnace at 80°C to 100°C and baked for 15 to 25 minutes until the base material and the fluoroplastic release film are no longer sticky, and the sheet is obtained after cooling.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention provides a segmented curing thermal conductive adhesive insulating sheet, which includes an addition curing system and a peroxide curing system. The addition curing system starts to react below 100°C, and the curing degree of the finished product can be controlled by adjusting the addition ratio of the crosslinking agent, from slight crosslinking to complete curing. The peroxide curing system starts to react when the temperature reaches 150°C, so the start of the crosslinking reaction can be controlled by controlling the ambient temperature.

[0017] The raw materials of the organosilicon addition system, the raw materials of the peroxide curing system and the thermal conductive filler are mixed evenly and pressed into a sheet, and the sheet is cured in a tunnel furnace at 80°C to 100°C for 15 to 25 minutes for a first-stage curing to obtain a soft sheet that does not adhere to the release film, and the first-stage cured sheet is overlapped between two aluminum sheets with an overlap size of 12.5*12.5mm, and a pressure of 40psi is added to the outer surface of the aluminum sheet, and then placed in a 150°C environment for a second-stage curing for 6 minutes. The thermal conductivity of the obtained thermal conductive adhesive insulating sheet is greater than 1.4W / m·K, and the bonding strength is greater than 1.4MPa;

[0018] The segmented curing thermally conductive adhesive insulating sheet material prepared by the present invention, when the molar ratio of vinyl content to silicon hydrogen content is controlled to be greater than or equal to 10:1, is heated and baked at 80°C to 100°C for 15 minutes to 25 minutes. Under the catalytic action of the catalyst, it is ensured that the vinyl double bonds and the silicon hydrogen bonds in the system react completely, and all silicon hydrogen bonds in the system are consumed. There will be no reaction during the subsequent storage process, so that the system remains stable. When the molar ratio of vinyl content to silicon hydrogen content is less than 10:1, the colloid still adheres to the surface of the protective release film after curing and cannot be released. When the ratio gradually exceeds 10:1, after cross-linking and curing, the colloid no longer adheres to the protective film, but can still remain soft and can remain stable for a long time when placed at room temperature. In actual use, the film is installed between the MOS block and the radiator, a certain pressure is applied, and it is placed in an ambient temperature of 150°C. The MOS block and the radiator are bonded together. After the colloid is completely cured, it has high shear strength, high insulation strength, high toughness, good elongation at break, excellent high and low temperature resistance, and can work continuously at a temperature of -40 to 200 ° C. The excellent electrical insulation performance ensures the safe use of components. When actually installed, it is only necessary to stick the MOS block and other components on the surface of the radiator with a thermally conductive adhesive insulating sheet, apply a certain pressure, and place it in a high temperature environment of 150 ° C for 6 minutes to completely cure. No tearing occurs during fixing, reducing rework operations, enhancing insulation and reliability, excellent electrical insulation and chemical stability, ultra-low thermal resistance, improving timely heat conduction, and ensuring the service life of components. The segmented curing thermally conductive adhesive insulating sheet of the present invention has a high thermal conductivity, can effectively conduct heat from electronic components, reduce the working temperature and improve equipment performance and reliability; high bonding strength can prevent components from falling off to ensure equipment stability; the manufacturing method is simple, does not require complex equipment and processes, and is easy to industrialize. DETAILED DESCRIPTION

[0019] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0020] Example 1

[0021] A segmented curing heat-conducting adhesive insulating sheet, wherein the heat-conducting adhesive base material is composed of the following components by weight: 5 parts of vinyl MQ silicone resin with a molecular weight of 2500, a viscosity of 2000cps, and a vinyl content of 0.08mmol / g; 0.6 parts of a hydrogen-containing silicone resin crosslinking agent with a molecular weight of 200-500, a viscosity of 230-350cps, and a hydrogen content of 1.36mmol / g; 0.2 parts of a catalyst with a platinum content of 2000ppm; 0.1 parts of an alkynyl cyclohexanol inhibitor with a concentration of 0.5%; 10 parts of a vinyl raw rubber with a molecular weight of 590,000; 0.5 parts of 96% 2,4-di-tert-butyl peroxide isopropylbenzene curing agent; 0.1 parts of 99% triallyl isocyanurate accelerator; 28.5 parts of 5um spherical alumina powder, 55 parts of 45um spherical alumina powder; add all the above materials into an internal mixer and mix for 30 minutes at a maximum mixing speed of 15 rpm to prevent excessive temperature due to extrusion during mixing. After the powder and colloid are evenly mixed, use a double-roll open mill to further mix the colloid evenly until the colloid does not stick to the rollers and the base material is refined. Product molding: put the refined base material into a 5-roll calender, and calender it step by step to a thickness of 0.15mm. Select a fluoroplastic release film with a peeling force of 3g as the base film, and apply the base material to the surface of the release film. After the first calendering is completed, two pieces of base material with a thickness of 0.15mm are bonded together by a laminating machine, and a glass fiber cloth with a basis weight of 24g / m2 is sandwiched in the middle to form a sandwich structure, with glass fiber in the middle and sheets covered with base material on both sides. The whole sheet is compacted again by a double-roll machine to obtain a tightly fitted sheet with a thickness of 0.3mm. The whole sheet is placed in a tunnel furnace at 80℃ and baked for 15 to 20 minutes until the base material and the fluoroplastic release film are completely separated. After cooling, it is the finished sheet.

[0022] Example 2

[0023] A segmented curing heat-conducting adhesive insulating sheet, wherein the heat-conducting adhesive base material is composed of the following components by weight: 10 parts of vinyl MQ silicone resin with a molecular weight of 2500, a viscosity of 2000cps, and a vinyl content of 0.08mmol / g; 1 part of a hydrogen-containing silicone resin crosslinking agent with a molecular weight of 200-500, a viscosity of 230-350cps, and a hydrogen content of 1.36mmol / g; 0.2 parts of a catalyst with a platinum content of 2000ppm; 0.1 parts of an alkynyl cyclohexanol inhibitor with a concentration of 0.5%; 5 parts of vinyl raw rubber with a molecular weight of 590,000; 0.25 parts of 96% 2,4-di-tert-butyl peroxide isopropylbenzene curing agent; 0.05 parts of 99% triallyl isocyanurate accelerator; 28.7 parts of 5um spherical alumina powder, 55 parts of 45um spherical alumina powder; add all the above materials into an internal mixer and mix for 30 minutes, with a maximum mixing speed of 15 rpm to prevent excessive temperature due to extrusion during mixing. After the powder and colloid are evenly mixed, use a double-roll open mill to further mix the colloid evenly until the colloid does not stick to the rollers and the base material is refined. Product molding: put the refined base material into a 5-roll calender, and calender it step by step to a thickness of 0.15mm. Select a fluoroplastic release film with a peeling force of 3g as the base film, and apply the base material to the surface of the release film. After the first calendering is completed, two pieces of base material with a thickness of 0.15mm are bonded together by a laminating machine, and a glass fiber cloth with a basis weight of 24g / m2 is sandwiched in the middle to form a sandwich structure, with glass fiber in the middle and sheets covered with base material on both sides. The whole sheet is compacted again by a double-roll machine to obtain a tightly fitted sheet with a thickness of 0.3mm. The whole sheet is placed in a tunnel furnace at 80℃ and baked for 15 to 20 minutes until the base material and the fluoroplastic release film are completely separated. After cooling, it is the finished sheet.

[0024] Example 3

[0025] A segmented curing heat-conducting adhesive insulating sheet, wherein the heat-conducting adhesive base material is composed of the following components by weight: 7.5 parts of vinyl MQ silicone resin with a molecular weight of 4000, a viscosity of 3000cps and a vinyl content of 0.05mmol / g; 0.5 parts of a hydrogen-containing silicone resin crosslinking agent with a molecular weight of 200-500, a viscosity of 230-350cps and a hydrogen content of 1.5mmol / g; 0.2 parts of a catalyst with a platinum content of 2000ppm; 0.1 parts of an alkynyl cyclohexanol inhibitor with a concentration of 0.5%; 7.5 parts of a vinyl raw rubber with a molecular weight of 500,000; 0.8 parts of 96% 2,4-di-tert-butyl peroxide isopropylbenzene curing agent; 0.1 parts of 99% triallyl isocyanurate accelerator; 28.3 parts of 2um spherical alumina powder, 55 parts of 45um spherical alumina powder; add all the above materials into an internal mixer and mix for 30 minutes at a maximum mixing speed of 15 rpm to prevent excessive temperature due to extrusion during mixing. After the powder and colloid are evenly mixed, use a double-roll open mill to further mix the colloid evenly until the colloid does not stick to the rollers and the base material is refined. Product molding: put the refined base material into a 5-roll calender, and calender it step by step to a thickness of 0.15mm. Select a fluoroplastic release film with a peeling force of 3g as the base film, and apply the base material to the surface of the release film. After the first calendering is completed, two pieces of base material with a thickness of 0.15mm are bonded together by a laminating machine, and a glass fiber cloth with a basis weight of 24g / m2 is sandwiched in the middle to form a sandwich structure, with glass fiber in the middle and sheets covered with base material on both sides. The whole sheet is compacted again by a double-roll machine to obtain a tightly fitted sheet with a thickness of 0.3mm. The whole sheet is placed in a tunnel furnace at 80℃ and baked for 15 to 20 minutes until the base material and the fluoroplastic release film are completely separated. After cooling, it is the finished sheet.

[0026] The thermally conductive adhesive insulating sheet obtained in Example 1-3 after a stage of curing was made into a standard test sample, and after high temperature curing at 150°C for 6 minutes, after cooling, relevant index tests were performed, and the test results are shown in Table 1. From the data in the table, it can be seen that the thermally conductive adhesive insulating sheet of Example 1-3, which is a staged curing sheet, has good shear strength, excellent electrical properties and mechanical properties.

[0027] Table 1. Thermal insulation sheet performance test of Examples 1-3

[0028]

[0029] It can be seen from the test comparison data that by adjusting the ratio of MQ resin and vinyl raw rubber, the shear strength, electrical properties and physical properties of the thermally conductive adhesive insulating bottle can be changed, which can meet different needs and has a wider range of uses.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A segmented curing thermally conductive adhesive insulating sheet, wherein a silicone addition system and a peroxide curing system coexist in the system, characterized in that: The invention comprises the following components in parts by weight: 5-10 parts of vinyl MQ silicone resin, 0.1-1.0 parts of cross-linking agent, 0.1-0.5 parts of platinum catalyst, 0.01-0.1 parts of inhibitor, 5-10 parts of vinyl raw rubber, 0.25-1 parts of peroxide curing agent, 0.05-0.1 parts of accelerator and 50-85 parts of thermal conductive filler.

2. The segmented curing thermal conductive adhesive insulating sheet according to claim 1, characterized in that: The vinyl MQ silicone resin has a molecular weight of 2000-4000, a viscosity of 2000-3000 cps, and a vinyl content of 0.05-0.15 mmol / g.

3. The segmented curing thermal conductive adhesive insulating sheet according to claim 2, characterized in that: The crosslinking agent is a double hydrogen-terminated siloxane with a molecular weight of 200-500, a viscosity of 230-350 cps, and a hydrogen content of 0.5-1.6 mmol / g.

4. The segmented curing thermal conductive adhesive insulating sheet according to claim 1, characterized in that: The platinum catalyst is a chloroplatinic acid platinum complex with a platinum content of 2000 PPM.

5. The segmented curing thermal conductive adhesive insulating sheet according to claim 1, characterized in that: The inhibitor was alkynylcyclohexanol at a concentration of 0.5%.

6. The segmented curing thermal conductive adhesive insulating sheet according to claim 1, characterized in that: The molecular weight of the vinyl raw rubber is 500,000-600,000.

7. The segmented curing thermally conductive adhesive insulating sheet according to claim 1, characterized in that: The peroxide curing agent is 2,4-di-tert-butyl peroxide isopropylbenzene, and the effective substance content is ≥96%.

8. The segmented curing thermally conductive adhesive insulating sheet according to claim 1, characterized in that: The accelerator is triallyl isocyanurate, and the effective substance content is 99%.

9. The segmented curing thermally conductive adhesive insulating sheet according to claim 8, characterized in that: The thermal conductive filler is a combination of two types of aluminum oxide powders with different particle sizes.

10. A method for preparing a segmented curing thermally conductive adhesive insulating sheet according to any one of claims 1 to 9, characterized in that: The following steps are involved: Add vinyl MQ silicone resin, crosslinking agent, platinum catalyst, inhibitor, vinyl raw rubber, peroxide curing agent and accelerator into an internal mixer, mix evenly at room temperature, and then use a double-roller mixer to mix the rubber until the colloid is mixed evenly and does not stick to the rollers to obtain the base material; product molding: select a fluoroplastic release film with a peeling force of 3g as the base film, and a glass fiber cloth with a basis weight of 25±5g / m2 as the reinforcing material, and use a 5-roller step-by-step calendering method to calender the evenly mixed base material into a sheet. After two calenderings, a sheet with glass fiber in the middle and base material covering both sides is initially formed. Put the entire sheet into a tunnel furnace at 80℃~100℃ and bake for 15 to 25 minutes until the base material and the fluoroplastic release film are no longer sticky, and then cool it down to obtain the product.

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