Multilayer vertical orientation carbon fiber silica gel heat-conducting gasket and preparation method thereof

Abstract

The invention discloses a multilayer vertical orientation carbon fiber silica gel heat-conducting gasket and a preparation method thereof, the multilayer vertical orientation carbon fiber silica gel heat-conducting gasket comprises silica gel layers and orientation carbon fiber layers, the silica gel layers and the orientation carbon fiber layers are alternately arranged, and the silica gel layers play roles in bonding and providing material elasticity; the orientation of carbon fibers in the orientation carbon fiber layer is achieved in a rolling brushing mode, the carbon fibers are distributed in a concentrated mode, improvement of the heat conduction performance is better facilitated, and the heat conduction gasket prepared through the method is simple and convenient in preparation process, low in price and suitable for industrial large-scale production.

Description

Technical Field

[0001] The invention relates to the field of carbon fiber silicone thermal conductive gaskets, and in particular to a multi-layer vertically oriented carbon fiber silicone thermal conductive gasket and a preparation method thereof. Background Art

[0002] With the rapid development of the electronic information industry, especially the rapid development of 5G informatization, the power of semiconductor chip equipment has been greatly enhanced. Electronic components will generate a lot of heat during the highly integrated operation process, and the thermal conductivity of existing thermal conductive materials can no longer meet the heat dissipation requirements of the chip, which will directly affect the service life and operating efficiency of electronic components.

[0003] Carbon fiber has excellent thermal conductivity in the axial direction. By regulating the carbon fiber to orient it in a specific direction, a thermally conductive gasket with high thermal conductivity can be obtained. Currently, the more common methods for achieving carbon fiber orientation include magnetic field orientation and flow channel orientation. The magnetic field orientation efficiency is low and is not suitable for large-scale industrial applications, while the flow channel orientation method is difficult to achieve a good degree of orientation. In response to the above problems, a solution is proposed below. Summary of the invention

[0004] The purpose of the present invention is to provide a multi-layer vertically oriented carbon fiber silicone thermal conductive gasket and a preparation method thereof, which has the advantages of simple operation, easy industrial large-scale production, and improved thermal conductivity of the gasket.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions: A multi-layer vertically oriented carbon fiber silicone thermal conductive pad and a preparation method thereof, comprising a silicone layer and an oriented carbon fiber layer, the preparation method comprising the following steps: S1. Weigh silica gel A, silica gel B and alumina powder according to the ratio, and stir them evenly with a planetary mixer to obtain a silica gel mixture; S2. The silicone mixture is scraped onto the PTFE film to form a silicone film of uniform thickness, wherein the silicone film is the silicone layer; S3. The carbon fiber is evenly spread on the surface of the silicone film formed by the doctor blade, and the carbon fiber and the silicone film are rolled with a roller brush along a fixed direction to achieve the orientation of the carbon fiber to obtain a carbon fiber / silicone composite film; S4. The carbon fiber / silicone composite film is placed on a heating table and heated to achieve semi-curing of the silicone to obtain a semi-cured carbon fiber / silicone composite film; S5. Demolding the semi-cured carbon fiber / silicone composite film from the PTFE film, stacking the layers, and curing them into a block using a hot press to obtain a block of silicone; S6. Cut the block silicone into sheets perpendicular to the direction of carbon fiber orientation to obtain a multi-layer vertically oriented carbon fiber silicone thermal conductive gasket.

[0006] Preferably, the weight proportions of the components in step S1 are: silica gel A: 50 parts, silica gel B: 45-50 parts, and alumina: 0-50 parts.

[0007] Preferably, the silica gel A in step S1 is composed of vinyl silicone oil, a platinum catalyst, and an inhibitor; and the silica gel B is composed of vinyl silicone oil and hydrogen-containing silicone oil.

[0008] Preferably, the diameter of the aluminum oxide in step S1 is 2-6 microns.

[0009] Preferably, the carbon fibers of the oriented carbon fiber layer have a diameter of 7 microns and a length of 1 mm.

[0010] Preferably, the thickness of the silica gel film in step S2 is 100-150 μm.

[0011] Preferably, the bristles of the roller brush in S3 are made of PA material, the bristle spacing is 0.5 mm, the bristle diameter is 150 µm, the rotation speed of the roller brush is 10-50 rpm, and the movement speed of the roller brush is 1-10 m / min.

[0012] Preferably, the heating temperature of the heating table in S4 is 100-150° C., and the semi-curing time is 3-5 min.

[0013] Preferably, the temperature of the hot press in S5 is 100-150° C., and the curing time of the silica gel is 15-30 min.

[0014] Preferably, the thickness of the silicone sheet cut in S6 is 0.1-1 mm.

[0015] The beneficial effects of the present invention are: (1) The present invention forms a multi-layer carbon fiber structure by rolling and brushing the carbon fiber onto the surface of the silicone rubber, stacking and hot-pressing the multi-layers, and the carbon fiber is concentrated and dispersed in the layers, which greatly improves the effective concentration and is beneficial to the improvement of thermal conductivity.

[0016] (2) The multi-layer vertically oriented carbon fiber silicone thermal conductive gasket prepared by the present invention has silicone layers and carbon fiber layers arranged alternately. The silicone layers ensure good bonding between the layers and provide excellent resilience, while the carbon fiber layers ensure good thermal conductivity.

[0017] (3) The present invention utilizes the narrow spacing between the bristles of the roller brush to orient the carbon fibers along the moving direction of the roller brush.

[0018] (4) The multi-layer vertically oriented carbon fiber silicone thermal conductive gasket prepared by the present invention has the characteristics of simple preparation method, good thermal conductivity, and is suitable for industrial large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a SEM image of a multi-layer vertically oriented carbon fiber silicone thermal conductive gasket in an embodiment; Figure 2 This is an embodiment of a multi-layer vertically oriented carbon fiber silicone thermal conductive gasket. DETAILED DESCRIPTION

[0020] The following is only a preferred embodiment of the present invention, and the protection scope is not limited to this embodiment. All technical solutions under the concept of the present invention should belong to the protection scope of the present invention. The same parts are represented by the same reference numerals.

[0021] A multi-layer vertically oriented carbon fiber silicone thermal conductive gasket in this embodiment includes a silicone layer and an oriented carbon fiber layer. The silicone layer includes the following components in parts by weight: 50 parts of silicone A and 48 parts of silicone B.

[0022] The preparation method thereof comprises the following steps: S1. Weigh silica gel A and silica gel B according to the ratio and stir them evenly with a planetary mixer to obtain a silica gel mixture; S2. Apply the silicone mixture onto the PTFE film to form a uniform silicone film with a thickness of 100 µm; S3. Sprinkle the carbon fiber evenly onto the surface of the silicone film formed by scraping, and use a roller brush to roll the carbon fiber and silicone film in a fixed direction, with a roller brush speed of 10 rpm and a moving speed of 1m / min; S4. Place the carbon fiber / silicone composite film in S3 on a heating table and heat it at 110°C for 5.0 min. S5. Demolding the semi-cured carbon fiber / silicone composite film from the PTFE film, stacking multiple layers, and hot pressing at 110°C for 20 min; S6. Cut the block silicone into sheets with a thickness of 0.5 mm perpendicular to the orientation of the carbon fiber to obtain a multi-layer vertically oriented carbon fiber silicone thermal conductive pad. According to the ASTM D-5470-01 test standard, the thermal conductivity is 12.5 W / (m﹒K).

[0023] A multi-layer vertically oriented carbon fiber silicone thermal conductive gasket in this embodiment includes a silicone layer and an oriented carbon fiber layer. The silicone layer includes the following components in parts by weight: 50 parts of silicone A and 50 parts of silicone B.

[0024] The preparation method thereof comprises the following steps: S1. Weigh silica gel A and silica gel B according to the ratio and stir them evenly with a planetary mixer to obtain a silica gel mixture; S2. Apply the silicone mixture onto the PTFE film to form a uniform silicone film with a thickness of 120 µm; S3. Sprinkle the carbon fiber evenly onto the surface of the silicone film formed by scraping, and use a roller brush to roll the carbon fiber and silicone film in a fixed direction, with a roller brush speed of 15 rpm and a moving speed of 5 m / min; S4. Place the carbon fiber / silicone composite film in S3 on a heating table and heat it at 120°C for 4.0 min. S5. Demolding the semi-cured carbon fiber / silicone composite film from the PTFE film, stacking multiple layers, and hot pressing at 120°C for 15 min; S6. Cut the block silica gel into sheets with a thickness of 0.5 mm perpendicular to the orientation of the carbon fibers to obtain a multi-layer vertically oriented carbon fiber silica gel thermal conductive pad. According to the ASTM D-5470-01 test standard, the thermal conductivity is 13.0 W / (m﹒K).

[0025] A multi-layer vertically oriented carbon fiber silicone thermal conductive gasket in this embodiment includes a silicone layer and an oriented carbon fiber layer. The silicone layer includes the following components in parts by weight: 50 parts of silicone A and 50 parts of silicone B.

[0026] The preparation method thereof comprises the following steps: S1. Weigh silica gel A and silica gel B according to the ratio and stir them evenly with a planetary mixer to obtain a silica gel mixture; S2. Apply the silicone mixture onto the PTFE film to form a uniform silicone film with a thickness of 135 µm; S3. Sprinkle the carbon fiber evenly onto the surface of the silicone film formed by scraping, and use a roller brush to roll the carbon fiber and silicone film in a fixed direction, with a roller brush speed of 20 rpm and a moving speed of 10 m / min; S4. Place the carbon fiber / silicone composite film in S3 on a heating table and heat it at 140°C for 3.0 min. S5. Demolding the semi-cured carbon fiber / silicone composite film from the PTFE film, stacking multiple layers, and hot pressing at 140°C for 13 min; S6. Cut the block silica gel into sheets with a thickness of 0.5 mm perpendicular to the orientation of the carbon fibers to obtain a multi-layer vertically oriented carbon fiber silica gel thermal conductive pad. According to the ASTM D-5470-01 test standard, the thermal conductivity is 12.8 W / (m﹒K).

[0027] The specific embodiments described above further illustrate the technical problems, technical solutions and beneficial effects solved by the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-layer vertically oriented carbon fiber silicone thermal conductive pad and a preparation method thereof, comprising a silicone layer and an oriented carbon fiber layer, characterized in that: The preparation method comprises the following steps: S1. Weigh silica gel A, silica gel B and alumina powder according to the ratio, and stir them evenly with a planetary mixer to obtain a silica gel mixture; S2. The silicone mixture is scraped onto the PTFE film to form a silicone film of uniform thickness, wherein the silicone film is the silicone layer; S3. The carbon fiber is evenly spread on the surface of the silicone film formed by the doctor blade, and the carbon fiber and the silicone film are rolled with a roller brush along a fixed direction to achieve the orientation of the carbon fiber to obtain a carbon fiber / silicone composite film; S4. The carbon fiber / silicone composite film is placed on a heating table and heated to achieve semi-curing of the silicone to obtain a semi-cured carbon fiber / silicone composite film; S5. Demolding the semi-cured carbon fiber / silicone composite film from the PTFE film, stacking the layers, and curing them into a block using a hot press to obtain a block of silicone; S6. Cut the block silicone into sheets perpendicular to the direction of carbon fiber orientation to obtain a multi-layer vertically oriented carbon fiber silicone thermal conductive gasket.

2. A multi-layer vertically oriented carbon fiber silicone thermal conductive gasket and a preparation method thereof according to claim 1, characterized in that: The weight proportions of the components in step S1 are: silica gel A: 50 parts, silica gel B: 45-50 parts, and alumina: 0-50 parts.

3. A multi-layer vertically oriented carbon fiber silicone thermal conductive pad and a preparation method thereof according to claim 1, characterized in that: The silica gel A in step S1 is composed of vinyl silicone oil, platinum catalyst and polymerization inhibitor; the silica gel B is composed of vinyl silicone oil and hydrogen-containing silicone oil.

4. A multi-layer vertically oriented carbon fiber silicone thermal conductive gasket and a preparation method thereof according to claim 1, characterized in that: The diameter of the aluminum oxide in step S1 is 2-6 microns.

5. The multi-layer vertically oriented carbon fiber silicone thermal conductive pad and the preparation method thereof according to claim 1, characterized in that: The carbon fibers of the oriented carbon fiber layer have a diameter of 7 micrometers and a length of 1 mm.

6. The multi-layer vertically oriented carbon fiber silicone thermal conductive gasket and the preparation method thereof according to claim 1, characterized in that: The thickness of the silica gel film in step S2 is 100-150 μm.

7. The multi-layer vertically oriented carbon fiber silicone thermal conductive gasket and the preparation method thereof according to claim 1, characterized in that: The bristles of the roller brush in S3 are made of PA material, the bristle spacing is 0.5 mm, the bristle diameter is 150 µm, the rotation speed of the roller brush is 10-50 rpm, and the moving speed of the roller brush is 1-10 m / min.

8. The multi-layer vertically oriented carbon fiber silicone thermal conductive gasket and the preparation method thereof according to claim 1, characterized in that: The heating temperature of the heating table in S4 is 100-150° C., and the semi-curing time is 3-5 minutes.

9. The multi-layer vertically oriented carbon fiber silicone thermal conductive gasket and the preparation method thereof according to claim 1, characterized in that: The temperature of the hot press in S5 is 100-150° C., and the curing time of the silica gel is 15-30 minutes.

10. The multi-layer vertically oriented carbon fiber silicone thermal conductive gasket and the preparation method thereof according to claim 1, characterized in that: The thickness of the silicone sheet cut in S6 is 0.1-1 mm.

Images