A resin-based liquid metal heat-conducting insulating gasket and a method for manufacturing the same

Abstract

The application discloses a resin-based liquid metal heat-conducting insulating gasket and a preparation method thereof, and the wettability of liquid metal to resin is improved by using 12-(2-bromo-isobutylamine) dodecanoic acid and inorganic powder to perform surface modification on the liquid metal, a liquid metal layer is coated on the resin base, the liquid metal is bound by the resin to improve the stability of the liquid metal, the electric conductivity of the liquid metal is reduced, meanwhile, the liquid metal still has relatively high thermal conductivity and certain compressibility, and the performance defects of the liquid metal in the prior art are solved, and the liquid metal has excellent performance. The application can meet the working requirements of high-power electronic heat-generating components through testing.

Description

Technical Field

[0001] This invention relates to the field of thermal conductive materials technology, and in particular to a resin-based liquid metal thermally conductive insulating pad and its preparation method. Background Technology

[0002] With the continuous development of electronic device performance, the operating frequency of electronic chips is constantly increasing, leading to a corresponding increase in heat flux density and a rapid rise in the heat generated by electronic devices. If this heat cannot be effectively transferred and dissipated in a timely manner, it will severely reduce the continuous operating performance of high-power electronic devices and even shorten their lifespan. Studies have shown that a temperature increase of 10-15°C in electronic devices can result in a 50% reduction in expected lifespan and decrease system reliability. High-power electronic devices are equipped with heat sinks, such as vapor chambers, heat pipes, and phase change materials. However, the electronic heating components and heat sinks are usually not perfectly fitted together; the air between the layers acts as a poor thermal conductor, significantly reducing the efficiency of heat transfer to the heat sink. To increase the heat transfer efficiency of electronic devices, a gasket needs to be added between the electronic heating components and the heat sink. The performance requirements for this gasket mainly include high thermal conductivity, high insulation, good thermal stability, a certain degree of compressibility, and excellent sealing.

[0003] Most thermal pads currently used are made of silicone or silicone grease. Traditional silicone materials have thermal conductivity ranging from 0.5-4 W / m·K, which is insufficient for high heat transfer requirements. In contrast, metals possess ideal high thermal conductivity; however, most metal sheets are hard and prone to cavities on uneven surfaces, reducing heat transfer efficiency. Therefore, low-melting-point alloys with melting points below 200℃ are used, known as liquid metals. Typical liquid metals are alloys of elements such as mercury, lead, gallium, bismuth, and indium. Due to the high toxicity of mercury and lead, non-toxic elements like gallium and indium are more commonly used. Their melting point, viscosity, and other properties can be freely altered through composition adjustments, leading to their widespread research and application in thermal interface materials, flexible electronics, and smart electronics. Liquid metals, such as gallium-based liquid metals, have good fluidity and can effectively fill air gaps at interfaces; however, they are typically highly conductive, posing a short-circuit risk when used extensively in electronic devices, especially requiring measures to prevent leakage into circuits. Therefore, improving the stability of liquid metals and reducing their conductivity is a crucial issue. Summary of the Invention

[0004] This invention provides a resin-based liquid metal thermally conductive and insulating pad and its preparation method. By using 12-(2-bromoisobutylamine)dodecanoic acid and inorganic powder to modify the surface of liquid metal, its wettability to resin is improved and its compatibility with metals such as aluminum and copper is reduced. A liquid metal layer is coated on the resin base, and the liquid metal is bound by resin to improve its stability and reduce its electrical conductivity, while maintaining high thermal conductivity and a certain degree of compressibility. This invention solves the above-mentioned performance defects of liquid metal in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention provides a resin-based liquid metal thermally conductive insulating pad, the structure of which includes a thermally conductive resin base layer and a liquid metal layer. The thermally conductive resin base layer has an upper surface and a lower surface, and both the upper surface and the lower surface are coated with at least one layer of liquid metal.

[0006] A resin-based liquid metal thermally conductive insulating pad, comprising a thermally conductive resin base layer and a liquid metal layer, wherein the thermally conductive resin base layer has an upper surface and a lower surface, and both the upper surface and the lower surface are coated with at least one layer of liquid metal.

[0007] In the technical solution of the present invention, the thermally conductive resin substrate is prepared from the following raw materials in parts by weight: 50-200 parts of liquid resin, 100-800 parts of thermally conductive filler, 0.1-0.5 parts of retardant, 3-10 parts of curing agent and 3-10 parts of catalyst.

[0008] In the technical solution of this invention, the viscosity of the liquid resin is 100-5000 cps / 25℃.

[0009] In the technical solution of this invention, the liquid resin includes one or more combinations of dimethyl silicone oil, vinyl silicone oil, polyolefin and polyethylene oxide.

[0010] In the technical solution of this invention, the thermally conductive filler is one or more combinations of spherical alumina, aluminum nitride, boron nitride, zinc oxide, aluminum hydroxide, silicon micro powder, diamond micro powder, and carbon nanotubes.

[0011] In the technical solution of this invention, the delay agent is acetylenol cyclohexanol, the curing agent is hydrogen-containing silicone oil, and the catalyst is a platinum catalyst.

[0012] In the technical solution of the present invention, the liquid metal layer is composed of the following components calculated by weight: 95-100 parts of liquid metal, 0.01-5 parts of powder for modifying the liquid metal, and 25-50 parts of 12-(2-bromoisobutylamine)dodecanoic acid (CAS No.: 2095388-80-8).

[0013] In the technical solution of this invention, the liquid metal is a liquid metal with a melting point of -40 to 120°C; the liquid metal is one of gallium-indium alloy, gallium-tin alloy, indium-tin alloy, tin-bismuth alloy, indium-bismuth-tin alloy, and gallium-indium-tin alloy.

[0014] In the technical solution of the present invention, the powder used to modify the liquid metal is one or more of the following: aluminum oxide, zinc oxide, magnesium oxide, silicon oxide, boron nitride, aluminum nitride, tungsten oxide, chromium oxide, manganese oxide, copper oxide, silver oxide, molybdenum sulfide, and silver powder.

[0015] A method for preparing the above-mentioned resin-based liquid metal thermally conductive and insulating pad, characterized by comprising the following steps:

[0016] S1: Stir the liquid resin and thermally conductive filler in a mixing device until they are evenly mixed;

[0017] S2: After cooling the mixture obtained in step S1 to room temperature, add the delay agent and curing agent in sequence and stir to mix evenly. Then add the catalyst and continue stirring until the mixture is evenly mixed to obtain the thermally conductive resin base layer.

[0018] S3: The powder used to modify the liquid metal and 12-(2-bromoisobutylamine)dodecanoic acid are mixed with the liquid metal and added to a stirring and mixing device. The mixture is heated and stirred until it is homogeneous to obtain the modified liquid metal.

[0019] S4: Using a scraping device, the modified liquid metal is coated onto the upper and / or lower surface of the thermally conductive resin substrate to form a liquid metal layer with a thickness of 0.01-0.5 mm arranged parallel to the scraping direction on the thermally conductive resin substrate, thus obtaining a resin-based liquid metal thermally conductive insulating pad.

[0020] Preferably, the stirring and mixing conditions in steps S1 and S2 are: rotation speed 50-3000 r / min, temperature 20-80℃, time 5-60 min, and vacuum degree 30-100 Pa; the stirring and mixing conditions in step S3 are: rotation speed 3500-5000 r / min, temperature 100-120℃, time 20-30 min, and vacuum degree 30-100 Pa.

[0021] The beneficial effects of this invention are as follows: The resin-based liquid metal thermally conductive insulating pad and its preparation method of this invention utilize 12-(2-bromoisobutylamine)dodecanoic acid and inorganic powder to modify the liquid metal, effectively improving the affinity between the liquid metal and the resin. The prepared resin-based liquid metal thermally conductive insulating pad has higher stability than the unmodified liquid metal sheet, significantly reduces its conductivity, and maintains high thermal conductivity and a certain degree of compressibility, which can meet the working requirements of high-power electronic heating components, demonstrating significant effectiveness. Furthermore, this invention is convenient to apply and has low cost. Detailed Implementation

[0022] The preferred embodiments of the present invention will be described in detail below, with the aim of making the advantages and features of the present invention easier to understand, thereby providing a clearer and more definite definition of the scope of protection of the present invention.

[0023] Platinum catalysts are commercially available products, and their sources include, but are not limited to, the following websites:

[0024] https: / / gdkejunchi.cn.china.cn / supply / 4395176474.html

[0025] The amounts of raw materials used in Examples 1-5 below are shown in Table 1:

[0026] Table 1: Amount of raw materials used in Examples 1-5 (unit: g)

[0027]

[0028] The sources of some of the raw materials used in Examples 1-5 are shown in Table 2 below:

[0029] Table 2: Sources of some raw materials used in Examples 1-5

[0030]

[0031] Example 1

[0032] 5g of vinyl silicone oil with a viscosity of 1500cps / 25℃ and 10g of spherical alumina powder were stirred and mixed for 10 minutes at a temperature of 50℃, a rotation speed of 500r / min, and a vacuum degree of 50Pa.

[0033] After cooling the obtained mixture to room temperature, 0.002 g of retarder and 0.05 g of curing agent were added sequentially and stirred for 10 minutes at 50°C, 500 r / min, and 50 Pa. Then, 0.05 g of catalyst was added and stirring continued for 5 minutes, while maintaining the same temperature, speed, and vacuum, to obtain a thermally conductive resin substrate layer. 0.05 g of alumina powder and 0.25 g of 12-(2-bromoisobutylamine)dodecanoic acid were mixed with 1 g of indium bismuth tin alloy liquid metal and added to a mixing apparatus. The mixture was heated and stirred for 25 minutes at 4000 r / min, 120°C, and 50 Pa to obtain a modified liquid metal.

[0034] The modified liquid metal was divided into two equal parts and coated onto the upper and lower surfaces of the thermally conductive resin substrate using a scraping device. This formed a liquid metal layer with a thickness of 0.1 mm arranged parallel to the upper and lower surfaces of the thermally conductive resin substrate along the scraping direction, resulting in a resin-based liquid metal thermally conductive insulating pad.

[0035] Example 2

[0036] The difference from Example 1 lies in the amount of modified liquid metal used. Specifically, 0.1g of alumina powder, 0.5g of 12-(2-bromoisobutylamine)dodecanoic acid, and 2g of indium bismuth tin alloy liquid metal are used.

[0037] The other raw materials and preparation steps are the same as in Example 1.

[0038] Example 3

[0039] The difference from Example 1 lies in the amount of modified liquid metal used. Specifically, 0.15g of alumina powder, 0.75g of 12-(2-bromoisobutylamine)dodecanoic acid, and 3g of indium bismuth tin alloy liquid metal are used.

[0040] The other raw materials and preparation steps are the same as in Example 1.

[0041] Example 4

[0042] The difference from Example 1 lies in the material composition and mixing conditions of the thermally conductive resin substrate. Specifically, 5g of dimethyl silicone oil with a viscosity of 1000cps / 25℃ and 10g of boron nitride powder were stirred and mixed for 10 minutes at a temperature of 50℃, a rotation speed of 250r / min, and a vacuum degree of 50Pa.

[0043] The other raw materials and preparation steps are the same as in Example 1.

[0044] Example 5

[0045] The difference from Example 1 lies in the material composition of the modified liquid metal. Specifically, it contains 0.05g of boron nitride powder, 0.25g of 12-(2-bromoisobutylamine)dodecanoic acid, and 1g of gallium indium alloy liquid metal.

[0046] The other raw materials and preparation steps are the same as in Example 1.

[0047] Thermal conductivity and breakdown voltage tests were performed on the above embodiments, and the test results are shown in Table 3 below.

[0048] Table 3: Performance Test Results of Examples 1-5

[0049]

[0050]

[0051] The data in the table and the performance during the experiment show that this invention improves the stability and insulation of liquid metal while maintaining a high thermal conductivity. Specific parameters can be adjusted by controlling the amount of liquid metal used. The above descriptions are merely embodiments of this invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made using the description of this invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this invention.

Claims

1. A resin-based liquid metal thermally conductive and insulating pad, characterized in that, The resin-based liquid metal thermally conductive insulating pad includes a thermally conductive resin base layer and a liquid metal layer. The thermally conductive resin base layer has an upper surface and a lower surface, and both the upper surface and the lower surface are coated with at least one layer of liquid metal. The liquid metal layer is composed of the following components in parts by weight: 95-100 parts liquid metal, 0.01-5 parts powder for modifying the liquid metal, and 25-50 parts 12-(2-bromoisobutylamine)dodecanoic acid. The thermally conductive resin base layer is prepared from the following raw materials in parts by weight: 50-200 parts liquid resin, 100-800 parts thermally conductive filler, 0.1-0.5 parts retardant, 3-10 parts curing agent, and 3-10 parts catalyst.

2. The resin-based liquid metal thermally conductive and insulating pad according to claim 1, characterized in that, The viscosity of the liquid resin is 100–5000 cps at 25°C.

3. The resin-based liquid metal thermally conductive and insulating pad according to claim 1, characterized in that, The liquid resin includes one or more combinations of dimethyl silicone oil, vinyl silicone oil, polyolefin, and polyethylene oxide.

4. The resin-based liquid metal thermally conductive and insulating pad according to claim 1, characterized in that, The thermally conductive filler is one or more combinations of spherical alumina, aluminum nitride, boron nitride, zinc oxide, aluminum hydroxide, silicon micro powder, diamond micro powder, and carbon nanotubes.

5. The resin-based liquid metal thermally conductive and insulating pad according to claim 1, characterized in that, The retardant is acetylenol, the curing agent is hydrogen-containing silicone oil, and the catalyst is a platinum catalyst.

6. The resin-based liquid metal thermally conductive and insulating pad according to claim 1, characterized in that, The liquid metal is a liquid metal with a melting point of -40 to 120°C; the liquid metal is one of gallium-indium alloy, gallium-tin alloy, indium-tin alloy, tin-bismuth alloy, indium-bismuth-tin alloy, and gallium-indium-tin alloy.

7. The resin-based liquid metal thermally conductive and insulating pad according to claim 1, characterized in that, The powder used to modify the liquid metal is one or more of the following: aluminum oxide, zinc oxide, magnesium oxide, silicon oxide, boron nitride, aluminum nitride, tungsten oxide, chromium oxide, manganese oxide, copper oxide, silver oxide, molybdenum sulfide, and silver powder.

8. A method for preparing a resin-based liquid metal thermally conductive and insulating pad as described in any one of claims 1 to 7, characterized in that, The steps include the following: S1: Stir the liquid resin and thermally conductive filler in a mixing device until they are evenly mixed; S2: After cooling the mixture obtained in step S1 to room temperature, add the delay agent and curing agent in sequence and stir to mix evenly. Then add the catalyst and continue stirring until the mixture is evenly mixed to obtain the thermally conductive resin base layer. S3: The powder used to modify the liquid metal and 12-(2-bromoisobutylamine)dodecanoic acid are mixed with the liquid metal and added to a stirring and mixing device. The mixture is heated and stirred until it is homogeneous to obtain the modified liquid metal. S4: Using a scraping device, the modified liquid metal is coated onto the upper and / or lower surface of the thermally conductive resin substrate to form a liquid metal layer with a thickness of 0.01~0.5mm arranged parallel to the scraping direction on the thermally conductive resin substrate, thus obtaining a resin-based liquid metal thermally conductive insulating pad.

9. The preparation method according to claim 8, characterized in that: The stirring and mixing conditions in steps S1 and S2 are: rotation speed 50~3000 r / min, temperature 20~80°C, time 5~60 min, and vacuum degree 30~100 Pa; the stirring and mixing conditions in step S3 are: rotation speed 3500~5000 r / min, temperature 100~120°C, time 20~30 min, and vacuum degree 30~100 Pa.

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