Defoaming and subpackaging method of heat-conducting silica gel

Abstract

The invention provides a defoaming and sub-packaging method of heat-conducting silica gel. The defoaming and sub-packaging method comprises the following steps: stirring and mixing all materials for forming the heat-conducting silica gel in vacuum according to a set proportion; the stirred mixed material is vacuumized, and then the mixed material is subpackaged into a tank body; carrying out gradient centrifugal defoaming treatment on the mixed material in the tank body; and pressing the centrifuged material into a needle cylinder tube from the bottom of the centrifugal tank to obtain a subpackaged heat-conducting silica gel finished product. According to the invention, the good defoaming effect of the heat-conducting silica gel can be realized, the comprehensive performance such as the heat conductivity of the heat-conducting silica gel is improved, the quality stability of the product is greatly improved, and the production efficiency of the heat-conducting silica gel defoaming process is improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor heat dissipation materials, and specifically, to a defoaming and packaging method for thermal conductive silicone gel. Background Art

[0002] With the rapid development of the new energy, integrated circuit, electronic and electrical, and communication fields, the power density of electronic components and semiconductor chips continues to rise, and the heat dissipation requirements are becoming increasingly stringent. As a key heat dissipation material, silicone gel is widely used in the thermal interface materials of electronic components and semiconductor chips due to its high thermal conductivity, excellent compressibility, and interfacial adhesion ability. However, during the preparation and processing of silicone gel, the problem of residual bubbles severely restricts its performance stability and reliability.

[0003] On the one hand, the presence of bubbles inside the silicone gel directly damages its thermal conductivity. The thermal conductivity of air bubbles (0.024 W / (m·K)) is much lower than that of the silicone gel matrix, resulting in an increase in its interfacial thermal resistance and a decrease in heat dissipation efficiency. On the other hand, bubbles weaken the mechanical strength of the material, causing local stress concentration during compression or deformation, and accelerating the risk of interfacial delamination. In addition, during the curing stage of silicone gel (such as heat treatment at 120 °C), if the bubbles are not fully removed, the expansion of bubbles at high temperatures may cause damage to the internal structure of the material, affecting the product yield. Therefore, eliminating bubbles in silicone gel is particularly important.

[0004] In the prior art, the defoaming methods for silicone gel mainly rely on vacuum defoaming (such as planetary mixers combined with a vacuum environment) and mechanical stirring processes. However, the high viscosity characteristics of silicone gel lead to low efficiency of traditional vacuum defoaming and it is difficult to completely eliminate microbubbles. Defoaming by mechanical stirring may introduce more bubbles due to insufficient shear force or improper parameters. In addition, some processes improve the defoaming effect by adding chemical defoamers, but the residual defoamers may reduce the viscosity, heat resistance, and long-term stability of the silicone gel, and even cause interfacial delamination with the substrate. Researchers have conducted in-depth studies on methods to optimize defoaming and improve defoaming efficiency. Among them, Patent CN118750910A combines vacuum defoaming, ultrasonic vibration defoaming, stirring defoaming, and up-and-down vibration defoaming, improving the defoaming efficiency. However, this method of adhesive is only applicable to the defoaming of large quantities of adhesives and cannot effectively defoam small canned adhesives. Patent CN110477251A uses an electromagnetic vibrator to perform up-and-down vibration defoaming on canned materials, effectively improving the bubble problem of canned materials. However, this vibration method is very likely to reduce the viscosity of materials such as silicone gel, affecting the use performance of the materials. Some manufacturers also take the method of vacuum stirring and pumping to remove bubbles, then evacuating again for defoaming, and pressing and canning to obtain the silicone gel samples required by the production line. However, this defoaming method is single, and there are problems such as slow deep defoaming and residual bubbles in materials with high viscosity.

[0005] Another limitation of current defoaming technologies lies in process compatibility. For example, high-viscosity silicone gels need to be quickly defoamed before curing, but existing vacuum equipment is difficult to achieve deep degassing in a short time; while surface modification technologies such as corona treatment can only improve interfacial adhesion and cannot solve the internal bubble problem. Therefore, there is an urgent need to develop an efficient, low-residue defoaming and packaging method applicable to high-viscosity thermal conductive silicone gels to solve at least one of the above technical problems and improve the comprehensive performance and industrial production efficiency of thermal conductive silicone gels. Summary of the Invention

[0006] In view of the defects in the prior art, an object of the present application is to provide a defoaming and packaging method for thermal conductive silicone gels.

[0007] The present application provides a defoaming and packaging method for thermal conductive silicone gels, including:

[0008] Vacuum stirring and mixing the materials for forming the thermal conductive silicone gel in a set ratio;

[0009] Performing vacuum pumping on the stirred mixed materials, and then filling the mixed materials into a tank body;

[0010] Performing gradient centrifugal defoaming treatment on the mixed materials in the tank body;

[0011] Pressing the centrifuged materials from the bottom of the centrifugation tank into a syringe tube to obtain a packaged finished product of thermal conductive silicone gel.

[0012] Optionally, the vacuum stirring and mixing of the materials for forming the thermal conductive silicone gel in a set ratio includes: vacuum stirring and mixing a silicone gel base gum, a thermal conductive filler, a crosslinking agent, and a catalyst in a set ratio, wherein the weight percentages of the materials are: the thermal conductive filler is 30% - 40%, the crosslinking agent is 0.5% - 3%, the catalyst is 0 - 0.5%, and the balance is the silicone gel base gum.

[0013] Optionally, the thermal conductive filler is a solid material with a thermal conductivity greater than 10 W / m*K.

[0014] Optionally, in the vacuum stirring and mixing of the materials for forming the thermal conductive silicone gel in a set ratio: the vacuum degree is less than or equal to -0.08 MPa, the stirring speed is 50 revolutions per minute to 600 revolutions per minute, and the stirring time is 10 minutes to 240 minutes.

[0015] Optionally, the vacuum pumping of the stirred mixed materials includes: first pressing down the pressing rod of the material pressing machine to seal the material cylinder that has been vacuum stirred in the vacuum mixer, and then using a vacuum pump to perform vacuum pumping treatment on the stirred materials again.

[0016] Optionally, the stirred material is vacuumed again using a vacuum pump, wherein the vacuum degree of the vacuum pump is ≤100 Pa, and the vacuuming time is 1 minute to 30 minutes.

[0017] Optionally, the step of packing the mixed material into tanks comprises: applying a pressure of 0.1 MPa to 25 MPa on the upper portion of the pressing rod to press the vacuum-treated mixed material into a plurality of tanks of predetermined capacity.

[0018] Optionally, the gradient centrifugal defoaming treatment of the mixed material in the tank body includes: placing the material in the tank body in a centrifugal defoaming and filling device, performing centrifugal treatment in two stages in an air atmosphere, and maintaining the temperature in the tank no higher than 25°C.

[0019] Optionally, the material in the tank is placed in a centrifugal defoaming and filling device and centrifuged in two stages in an air atmosphere, wherein: the first stage of centrifugal treatment is performed at a speed of 1000 to 3000 rpm for 2 to 20 minutes.

[0020] Optionally, the material in the tank is placed in a centrifugal defoaming and filling device and centrifuged in two stages in an air atmosphere, wherein the second stage of centrifugal treatment is performed at a speed of 4000 to 6000 rpm for 5 to 30 minutes.

[0021] The defoaming and packaging method of thermally conductive silicone gel provided in the present application uses a vacuum method to discharge large bubbles, and uses a gradient centrifugation method to cause tiny bubbles to float up, thereby achieving a good defoaming effect of the thermally conductive silicone gel, effectively improving the quality problems of the thermally conductive silicone gel such as poor thermal conductivity caused by bubbles, thereby improving the thermal conductivity and other comprehensive properties of the thermally conductive silicone gel. Moreover, the defoaming and packaging of the present application are completed simultaneously, and the integrated packaging method can avoid secondary pollution and the introduction of bubbles, thereby greatly improving the quality stability of the product, and can also effectively shorten the defoaming and packaging time, thereby improving the production efficiency of the thermally conductive silicone gel defoaming process.

[0022] Other technical effects brought about by the additional features will be further explained in the corresponding embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0024] Figure 1 The present invention is a flow chart of a method for defoaming and packaging thermally conductive silicone gel according to an exemplary embodiment. DETAILED DESCRIPTION

[0025] The present application will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can be made, and these all fall within the protection scope of the present application. The parts not described in detail in the following embodiments can be implemented using the prior art.

[0026] In the existing defoaming methods for thermal conductive silicone gel, there are problems such as difficult complete defoaming in vacuum, reduced stability of silicone gel, difficult small-tank defoaming, and affecting the material viscosity. Based on the above problems, the embodiments of the present application provide a defoaming and packaging method for thermal conductive silicone gel to solve the above existing problems.

[0027] Referring to Figure 1 As shown, in an embodiment of the present application, the defoaming and packaging method for thermal conductive silicone gel includes the following steps:

[0028] S1. Vacuum stir and mix the materials forming the thermal conductive silicone gel in a set ratio;

[0029] S2. Evacuate the stirred mixed materials, and then divide and package the mixed materials into the tank body;

[0030] S3. Perform gradient centrifugal defoaming treatment on the mixed materials in the tank body;

[0031] S4. Press the centrifuged materials from the bottom of the centrifugal tank into the syringe tube to obtain the packaged finished product of the thermal conductive silicone gel.

[0032] Specifically, through the steps of vacuum stirring, secondary vacuum canning, gradient centrifugal enhanced defoaming, and material pressing and canning in the above method, the large air bubbles are discharged by the vacuum method, and the gradient centrifugal method promotes the floating of the tiny air bubbles, so as to achieve a good defoaming effect of the thermal conductive silicone gel, effectively improving the quality problems such as poor heat conduction caused by air bubbles in the thermal conductive silicone gel, and thus improving the comprehensive performance such as the thermal conductivity of the thermal conductive silicone gel. In this method, defoaming and packaging are completed synchronously, which is an integrated packaging method.

[0033] It should be noted that the above centrifugal tank is a component of the centrifugal defoaming and packaging device used for centrifugal defoaming treatment. Before the tank body is centrifuged, it is installed in the centrifugal tank of the centrifugal defoaming and packaging device. There is an openable small hole at the bottom of the packaged tank body, and there is also a small hole at the bottom of the centrifugal tank. The positions of the small holes at the bottom of the tank body and the bottom of the centrifugal tank are the same. After the centrifugal treatment is completed, the materials flow through the small hole at the bottom of the tank body and the small hole at the bottom of the centrifugal tank, and are pressed into the syringe tube through the pipeline.

[0034] In the above embodiments of the present application, an efficient defoaming method combining secondary vacuum defoaming and gradient centrifugal defoaming is adopted to achieve a good defoaming effect of the thermal conductive silicone gel, effectively improving the quality problems such as poor heat conduction caused by bubbles in the thermal conductive silicone gel, and further enhancing the comprehensive performance such as the thermal conductivity of the thermal conductive silicone gel. Moreover, in the present application, defoaming and sub-packaging are completed synchronously. The integrated sub-packaging method can avoid secondary pollution and bubble introduction, thus greatly improving the quality stability of the product. In addition, it can effectively shorten the defoaming and sub-packaging time, thereby improving the production efficiency of the thermal conductive silicone gel defoaming process.

[0035] In order to provide a thermal conductive silicone gel with excellent comprehensive performance, in some specific embodiments of the present application, in S1, the silicone gel base glue, thermal conductive filler, cross-linking agent, and catalyst are vacuum stirred and mixed in a set ratio. Among them, the weight ratios of the respective materials are: the thermal conductive filler is 30% - 40%, the cross-linking agent is 0.5% - 3%, the catalyst is 0 - 0.5%, and the balance is the silicone gel base glue. By setting the component ratios of the respective materials, a balance is achieved among the heat conduction, insulation, rheology, and chemical stability of the thermal conductive silicone gel.

[0036] Exemplarily, the silicone gel base glue is any one or more of polydimethylsiloxane (PDMS), phenyl silicone oil, fluorosilicone resin, other vinyl silicone oils, or other modified silicone resins, thereby providing good flexibility to the thermal conductive silicone gel and reducing the contact thermal resistance by conforming to the chip surface. The cross-linking agent is any one or more of hydrogen-containing silicone oil or triethylsilane. The above cross-linking agent materials react with the silicone gel base glue to coat the filler, so as to enhance the compatibility between the filler and the base glue, etc. The catalyst is any one or more of platinum complex and tin-based catalysts to achieve curing of the material.

[0037] It should be noted that in some other embodiments, the components of the thermal conductive silicone gel further include functional additives. The weight ratios of the respective materials in the thermal conductive silicone gel are: the thermal conductive filler is 30% - 40%, the cross-linking agent is 0.5% - 3%, the catalyst is 0 - 0.5%, the functional additive is 0 - 2%, and the balance is the silicone gel base glue.

[0038] Exemplarily, the functional additive is any one or more of fumed silica, butylated hydroxytoluene, barium titanate, aluminum hydroxide, etc., to achieve functions such as preventing sedimentation of the thermal conductive filler, anti-aging, enhancing insulation, and flame retardancy.

[0039] In order to improve the thermal conductivity of the thermal conductive silicone gel, in some specific embodiments of the present application, the thermal conductive filler is a solid material with a thermal conductivity greater than 10 W / m*K.

[0040] Exemplarily, the thermal conductive filler includes, but is not limited to, any one or more of powders such as boron nitride, aluminum nitride, aluminum oxide, magnesium oxide, zinc oxide, graphene, silver powder, iron powder, copper powder, nickel powder, and aluminum powder.

[0041] To make the heat-conducting filler powder evenly dispersed in the silicone gel base glue and initially remove the large air bubbles in the silicone gel, the parameters of the vacuum stirring treatment are set according to factors such as the total weight of the materials, the viscosity and rheological properties of the silicone gel base glue, the particle size of the heat-conducting filler, the types and contents of other materials, etc. In some specific embodiments of the present application, the materials for forming the heat-conducting silicone gel are vacuum stirred and mixed according to a set ratio, where: the component materials are added to a vacuum mixer and vacuum stirred and mixed at a high speed. The degree of vacuum is less than or equal to -0.08 MPa, the stirring speed is 50 revolutions per minute to 600 revolutions per minute, and the stirring time is 10 minutes to 240 minutes.

[0042] In the above embodiments of the present application, through the method of vacuum stirring and mixing, the component materials can be mixed evenly and the large air bubbles in the heat-conducting silicone gel can be initially removed.

[0043] In order to achieve secondary vacuum treatment, in some specific embodiments of the present application, in S2, first press down the pressing rod of the pressing machine to seal the material cylinder that has been vacuum stirred in the vacuum mixer, and then use a vacuum pump to perform a secondary vacuum treatment on the stirred material.

[0044] Exemplarily, according to factors such as the viscosity and air bubble residue rate of the mixed material after stirring in S1 and the total weight of the mixed material after stirring, the degree of vacuum for the vacuum pump to evacuate is ≤ 100 Pa, and the evacuation time is 1 minute to 30 minutes.

[0045] In the above embodiments of the present application, through the first vacuum treatment by vacuum stirring in S1 and the second vacuum treatment by evacuation in S2, adopting the method of secondary vacuum defoaming can ensure that all the large air bubbles are removed.

[0046] In order to complete defoaming and packaging synchronously, in some specific embodiments of the present application, a pressing machine is used to pack the materials into small cans, and a pressure of 0.1 MPa to 25 MPa is applied to the upper part of the pressing rod to press the vacuum-treated mixed material into several tanks with a predetermined capacity.

[0047] Exemplarily, the capacity of each small can is 50 ml, 100 ml or 150 ml.

[0048] It should be noted that the capacity of the tank can also be other values, which are specifically determined according to the specifications required by the user. The applied pressure is determined according to factors such as the viscosity of the mixed material after stirring in S1, the cross-sectional area of the material device, and the capacity of the packaging small can, so as to quickly pack the mixed material into the small can without overflow.

[0049] In the above embodiments of the present application, through secondary vacuum canning and secondary removal of air bubbles in the materials, the large air bubbles in the heat-conducting silicone gel material can be further removed.

[0050] To deeply remove air bubbles from the material, in some specific embodiments of the present application, gradient centrifugation defoaming treatment is performed on the mixed material in the tank body, including: placing the material in the tank body into a centrifugal defoaming and sub-packaging device, and performing centrifugation treatment in two stages in an air atmosphere.

[0051] During the centrifugation treatment, it is necessary to first remove air bubbles with a large density difference. Determine the process parameters of the first-stage centrifugation treatment according to factors such as the viscosity, rheological properties, size and position of large-density air bubbles of the mixed material. In some specific embodiments of the present application, place the material in the tank body into a centrifugal defoaming and sub-packaging device, and perform centrifugation in two stages in an air atmosphere, where: the centrifugation treatment in the first stage is carried out at a speed of 1000 revolutions per minute to 3000 revolutions per minute for 2 minutes to 20 minutes.

[0052] In the above embodiments of the present application, air bubbles with a large density difference are removed through low-speed centrifugation treatment.

[0053] After removing the air bubbles with a large density difference, it is still necessary to further remove micro-bubbles. Determine the process parameters of the second-stage centrifugation treatment according to factors such as the viscosity, rheological properties, position and residual situation of micro-bubbles of the mixed material. In some specific embodiments of the present application, place the material in the tank body into a centrifugal defoaming and sub-packaging device, and perform centrifugation in two stages in an air atmosphere, where: the centrifugation treatment in the second stage is carried out at a speed of 4000 revolutions per minute to 6000 revolutions per minute for 5 minutes to 30 minutes.

[0054] In the above embodiments of the present application, through high-speed centrifugation treatment, micro-bubbles float up, thereby removing micro-bubbles.

[0055] Specifically, during the gradient centrifugation treatment, maintain the temperature in the tank not higher than 25°C.

[0056] Exemplarily, maintain the temperature in the tank within a preset temperature range through the tank wall cooling system. Load a cooling structure in the hollow structure of the tank wall of the centrifugal tank or on the outer side close to the centrifugal tube wall, and fill a phase change material in this structure to achieve temperature control.

[0057] It should be noted that the air bubbles with a large density difference have been removed in the first-stage centrifugation treatment, and only micro-bubbles remain; the second-stage centrifugation treatment is mainly to make the micro-bubbles float up and remove the remaining micro-bubbles. The bubble residual rate after the two-step centrifugation treatment has been reduced to a very low level. In addition, limited by the upper limit of the centrifugation speed of the equipment, adding more stages will not significantly reduce the bubble residual rate, and thus will not further improve the thermal conductivity of the thermal conductive silicone gel.

[0058] In the above embodiments of the present application, large-density-difference bubbles are removed by gradient centrifugation, and tiny bubbles are promoted to float. During centrifugation, a phase change material (including acetone, Freon, water, alcohol, paraffin, methanol, etc.) is used to control the temperature. The temperature mainly considers the type and performance of the material to be centrifuged, the centrifugation speed, the inflow mode and the filling amount of the phase change material, etc. The shear friction heat generation during centrifugation is effectively suppressed, the viscosity stability of the silicone gel can be ensured, and thus the quality stability of the packaged product can be improved.

[0059] Specifically, in S4, the pressing rod presses down from the top of the centrifuge tank, and the material in the small tank is pressed into the syringe tube from the bottom of the centrifuge tank through the catheter to obtain the packaged finished product of the thermally conductive silicone gel.

[0060] In the above embodiments of the present application, a modular design concept is adopted. First, silicone gel tanks of different specifications are selected for centrifugation, and then syringe tubes of different specifications are packaged. It can adapt to different customer needs, has strong scalability, is easy to mass-produce, and has significant economic benefits.

[0061] In the above embodiments of the present application, a combination of vacuum defoaming and gradient centrifugation defoaming is adopted, so that the bubbles inside the thermally conductive silicone gel are effectively eliminated. Further, combined with the phase change material cooling system, the material does not undergo a viscosity mutation during defoaming, thereby improving the comprehensive performance such as the thermal conductivity of the thermally conductive silicone gel. At the same time, the method in the above embodiments of the present application realizes the synchronous completion of centrifugation defoaming and packaging, improves the production efficiency of the defoaming and packaging process of the thermally conductive silicone gel, and has significant economic benefits.

[0062] In the above embodiments, each of the better features can be used alone in any one embodiment, and can also be used in any combination on the premise of not conflicting with each other. In addition, the parts not described in detail in the embodiments can be realized by the prior art.

[0063] The following is a further description of the present application in combination with specific application examples / comparative examples to better understand the above technical solutions of the present application. It should be understood that the following are only partial examples and are not used to limit the present application.

[0064] Application Example 1:

[0065] This Application Example 1 provides a method for defoaming and packaging a thermally conductive silicone gel, including the following steps:

[0066] Step S1: Add vinyl-terminated PDMS, alumina, hydrogen-containing silicone oil, and platinum complex to a vacuum mixer according to a mass ratio of 62.4:35:2.5:0.1, and perform high-speed vacuum stirring and mixing at a speed of 500 revolutions per minute for 30 minutes in a vacuum environment with a vacuum degree not exceeding -0.08 MPa.

[0067] Step S2: First, lower the pressure bar of the blanking press to seal the 100L material cylinder after stirring in S1. Subsequently, use a vacuum pump to evacuate the stirred material again, with a vacuum degree ≤ 100 Pa, maintain the vacuum for 1 minute, and then apply pressure to the upper part of the pressure bar. The pressure of the pressure bar is 2.5 MPa, and press the silicone gel after the secondary vacuum treatment into 10 small cans of 150 ml respectively.

[0068] Step S3: Place the small can materials obtained in S2 in a centrifugal defoaming and dispensing device, and perform centrifugal defoaming treatment in two stages in an air atmosphere. In the first stage, centrifuge at a low speed of 2000 revolutions per minute for 5 minutes to remove bubbles with large density differences; in the second stage, centrifuge at a high speed of 6000 revolutions per minute for 5 minutes, and maintain the temperature in the can ≤ 25 °C through the tank wall cooling system to make the micro-bubbles float up.

[0069] Step S4: Press the centrifuged material from the bottom of the centrifugal can into the syringe tube to obtain the finished product of the heat-conducting silicone gel after dispensing. Lower the pressure bar from the top of the centrifugal can to press the heat-conducting silicone gel in the small can from the bottom of the centrifugal can into the syringe tube through the conduit to obtain the finished product of the heat-conducting silicone gel after dispensing.

[0070] Application Example 2:

[0071] The defoaming and dispensing method of the heat-conducting silicone gel provided in Application Example 2 includes the following steps:

[0072] Step S1: Add fluorosilicone resin, boron nitride, triethylsilane, platinum complex, and fumed SiO2 into a vacuum mixer according to a mass ratio of 64.3:32:2.2:0.1:1.4, and perform high-speed vacuum stirring and mixing at a speed of 200 revolutions per minute for 45 minutes in a vacuum environment with a vacuum degree not exceeding -0.08 MPa.

[0073] Step S2: First, lower the pressure bar of the blanking press to seal the 100L material cylinder after stirring in S1. Subsequently, use a vacuum pump to evacuate the stirred material again, with a vacuum degree ≤ 100 Pa, maintain the vacuum for 3 minutes, and then apply pressure to the upper part of the pressure bar. The pressure of the pressure bar is 5.0 MPa, and press the silicone gel after the secondary vacuum treatment into 10 small cans of 100 ml respectively.

[0074] Step S3: Place the small can materials obtained in S2 in a centrifugal defoaming and dispensing device, and perform centrifugal defoaming treatment in two stages in an air atmosphere. In the first stage, centrifuge at a low speed of 1000 revolutions per minute for 10 minutes to remove bubbles with large density differences; in the second stage, centrifuge at a high speed of 4500 revolutions per minute for 15 minutes, and maintain the temperature in the can ≤ 25 °C through the tank wall cooling system to make the micro-bubbles float up.

[0075] Step S4: Press the centrifuged material from the bottom of the centrifuge tank into a 30 ml syringe tube to obtain the finished heat-conductive silicone gel product in a packaged form. Press the pressing rod down from the top of the centrifuge tank to press the heat-conductive silicone gel in the small tank from the bottom of the centrifuge tank into the syringe tube through a conduit to obtain the finished heat-conductive silicone gel product in a packaged form.

[0076] Comparative example:

[0077] In the comparative example, a conventional vacuum pumping process is used to defoam and package the heat-conductive silicone gel. Among them, the conventional vacuum pumping process includes: vacuum stirring - secondary vacuum pumping - pressing and packaging.

[0078] Vacuum stirring: Add vinyl-terminated PDMS, alumina, hydrogen-containing silicone oil, and platinum complex to a vacuum mixer in a mass ratio of 62.4:35:2.5:0.1, and carry out high-speed vacuum stirring and mixing at a rotation speed of 500 revolutions per minute for 30 minutes in a vacuum environment with a vacuum degree not exceeding -0.08 MPa.

[0079] Secondary vacuum pumping and packaging: First, press down the pressing rod of the pressing machine to seal the 100 L material cylinder after stirring in S1. Subsequently, use a vacuum pump to carry out secondary vacuum pumping treatment on the stirred material, with a vacuum degree ≤ 100 Pa, maintain the vacuum for 1 minute, and then apply pressure on the upper part of the pressing rod. The pressure of the pressing rod is 25 MPa, and the silicone gel after the secondary vacuum treatment is respectively pressed into the syringe tube.

[0080] Compare and evaluate the bubble residue rate, thermal conductivity, interfacial thermal resistance, and viscosity of the finished heat-conductive silicone gel product prepared in the application example with that in the comparative example. The detailed results are shown in Table 1 below.

[0081] Table 1 Performance of the heat-conductive silicone gel in the application example and the comparative example

[0082]

[0083] As can be seen from Table 1, the centrifugal defoaming and packaging process of the heat-conductive silicone gel provided in the above application example of the present application can effectively remove 99% of the microbubbles in the heat-conductive silicone gel, reduce its interfacial thermal resistance, and avoid process damage to high-viscosity products. Moreover, compared with the comparative example, the thermal conductivity of the heat-conductive silicone gel in Application Example 1 of the present application is increased by 17.9%, and the thermal conductivity of the heat-conductive silicone gel in Application Example 2 is increased by 5.1%.

[0084] In the embodiments of the present application, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0085] Some specific embodiments of the present application have been described above. It should be understood that the present application is not limited to the above specific embodiments, and those skilled in the art can make various deformations or modifications within the scope of the claims, which does not affect the essence of the present application. The above preferred features can be used in any combination without conflict.

Claims

1. A defoaming and dispensing method for a thermal conductive silicone gel, characterized in that, Including: Vacuum stirring and mixing the materials for forming the thermal conductive silicone gel according to a set ratio; Performing vacuum pumping on the stirred mixed materials, and then sub-packaging the mixed materials into a tank body; Performing gradient centrifugal defoaming treatment on the mixed materials in the tank body; Pressing the centrifuged materials from the bottom of the centrifugal tank into a syringe tube to obtain a sub-packed finished product of thermal conductive silicone gel.

2. The defoaming and packaging method of the thermal conductive silicone gel according to claim 1, characterized in that, The vacuum stirring and mixing the materials for forming the thermal conductive silicone gel according to a set ratio includes: vacuum stirring and mixing a silicone gel base gum, a thermal conductive filler, a cross-linking agent and a catalyst according to a set ratio, wherein the weight ratios of the materials are: the thermal conductive filler is 30% - 40%, the cross-linking agent is 0.5% - 3%, the catalyst is 0 - 0.5%, and the balance is the silicone gel base gum.

3. The defoaming and packaging method of the thermal conductive silicone gel according to claim 2, characterized in that, The thermal conductive filler is a solid material with a thermal conductivity greater than 10 W / m*K.

4. The defoaming and packaging method of the thermal conductive silicone gel according to claim 1, characterized in that, The vacuum stirring and mixing the materials for forming the thermal conductive silicone gel according to a set ratio, wherein: the vacuum degree is less than or equal to -0.08 MPa, the stirring speed is 50 revolutions per minute to 600 revolutions per minute, and the stirring time is 10 minutes to 240 minutes.

5. The defoaming and packaging method of the thermal conductive silicone gel according to claim 1, characterized in that The performing vacuum pumping on the stirred mixed materials includes: first pressing down the pressing rod of the material pressing machine to seal the material barrel that has undergone vacuum stirring in the vacuum mixer, and then using a vacuum pump to perform vacuum pumping on the stirred materials again.

6. The defoaming and dispensing method of the thermal conductive silicone gel according to claim 5, wherein The using a vacuum pump to perform vacuum pumping on the stirred materials again, wherein: the vacuum degree of the vacuum pump for vacuum pumping is ≤ 100 Pa, and the vacuum pumping time is 1 minute to 30 minutes.

7. The defoaming and packaging method of the thermal conductive silicone gel according to claim 5, characterized in that, The sub-packaging the mixed materials into a tank body includes: applying a pressure of 0.1 MPa to 25 MPa on the upper part of the pressing rod to press the vacuum-treated mixed materials into several tank bodies with a predetermined capacity.

8. The defoaming and packaging method of the thermal conductive silicone gel according to claim 1, wherein The performing gradient centrifugal defoaming treatment on the mixed materials in the tank body includes: placing the materials in the tank body in a centrifugal defoaming and sub-packaging device, and performing centrifugal treatment in two stages in an air atmosphere, and maintaining the temperature in the tank not higher than 25°C.

9. The defoaming and sub-packaging method of the thermal conductive silicone gel according to claim 8, characterized in that, The placing the materials in the tank body in a centrifugal defoaming and sub-packaging device and performing centrifugal treatment in two stages in an air atmosphere, wherein: the centrifugal treatment in the first stage is at a speed of 1000 revolutions per minute to 3000 revolutions per minute for 2 minutes to 20 minutes.

10. The defoaming and packaging method of the thermal conductive silicone gel according to claim 8, characterized in that, The placing the materials in the tank body in a centrifugal defoaming and sub-packaging device and performing centrifugal treatment in two stages in an air atmosphere, wherein: the centrifugal treatment in the second stage is at a speed of 4000 revolutions per minute to 6000 revolutions per minute for 5 minutes to 30 minutes.

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