Preparation method of high-temperature-resistant heat-conducting insulating sheet and high-temperature-resistant heat-conducting insulating sheet
By using fiberglass cloth and polytetrafluoroethylene as carriers in thermally conductive insulating sheets, combined with the use of plasticizers, the problem of insufficient temperature resistance of existing thermally conductive insulating sheets has been solved, achieving effective heat conduction in high-temperature environments, and making it suitable for equipment such as electric vehicles.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHENZHEN AOCHUAN TECH CO LTD
- Filing Date
- 2022-11-16
- Publication Date
- 2026-08-04
AI Technical Summary
Existing thermally conductive insulating sheets use silicone rubber as a carrier and can withstand temperatures up to 200°C over long periods, which is insufficient to meet the high-temperature application requirements of electric vehicles and other equipment.
Using fiberglass cloth as the substrate and polytetrafluoroethylene as the continuous phase to fill the thermally conductive powder, a high-temperature resistant thermally conductive insulating sheet is prepared by attaching the thermally conductive slurry to the fiberglass cloth and curing it to form a thermally conductive colloid. Plasticizers are added to improve the creep effect and reduce the interfacial thermal resistance.
It achieves long-term temperature resistance exceeding 250℃ and interfacial thermal resistance of less than 0.3℃-in2/W (@50psi), meeting the high-temperature requirements of electric vehicles and other equipment.
Smart Images
Figure CN116092756B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of thermal conductive sheet production technology, and in particular to a method for preparing a high-temperature resistant thermal conductive insulating sheet and the high-temperature resistant thermal conductive insulating sheet itself. Background Technology
[0002] Thermally conductive insulating sheets are devices that fill the air gaps between heat-generating components and heat sinks or metal bases. Their flexibility and elasticity allow them to cover very uneven surfaces. Thermally conductive insulating sheets can conduct heat from discrete components or the entire PCB to the metal casing or diffuser plate, thereby improving the efficiency and lifespan of heat-generating electronic components.
[0003] Electric vehicles commonly use lithium batteries for power. To maintain the optimal operating temperature of these batteries, PTC heaters are needed to heat them in winter. Considering heating efficiency, PTC thermistors with an operating temperature of at least 200°C are required. This necessitates that the thermally conductive insulating sheets used in the control components of electric vehicles withstand temperatures above 200°C for extended periods. However, existing thermally conductive insulating sheets use silicone rubber as a carrier, and their long-term temperature resistance does not exceed 200°C, making it difficult to meet the application requirements of devices such as electric vehicles. Summary of the Invention
[0004] In view of the aforementioned problems, this application is made to provide a method for preparing a high-temperature resistant thermally conductive insulating sheet and a high-temperature resistant thermally conductive insulating sheet that overcomes or at least partially solves the aforementioned problems, comprising:
[0005] A method for preparing a high-temperature resistant thermally conductive insulating sheet, comprising:
[0006] Mix 100 parts by weight of polytetrafluoroethylene emulsion, 10-300 parts by weight of plasticizer, 0-30 parts by weight of water and 100-500 parts by weight of thermally conductive filler to obtain thermally conductive slurry.
[0007] The thermally conductive paste is continuously applied to the fiberglass cloth and cured to form a thermally conductive colloid until the thickness of the fiberglass cloth with the thermally conductive colloid reaches the preset thickness, thereby obtaining a high-temperature resistant thermally conductive insulating sheet roll.
[0008] The high-temperature resistant thermally conductive insulating sheet roll is cut to obtain a high-temperature resistant thermally conductive insulating sheet.
[0009] Preferably, the polytetrafluoroethylene emulsion comprises, by weight, 55-65 parts polytetrafluoroethylene, 25-35 parts nonionic surfactant, and 5-15 parts water.
[0010] Preferably, the plasticizer comprises perfluoroalkane with 16-30 carbon atoms.
[0011] Preferably, the plasticizer includes at least one of perfluorohexadecane and perfluoroeicosane.
[0012] Preferably, the thermally conductive filler includes at least one of alumina and boron nitride.
[0013] Preferably, the step of mixing 100 parts by weight of polytetrafluoroethylene emulsion, 10-300 parts by weight of plasticizer, 0-30 parts by weight of water, and 100-500 parts by weight of thermally conductive filler includes:
[0014] Add 100 parts by weight of polytetrafluoroethylene emulsion, 10-300 parts by weight of plasticizer, 0-30 parts by weight of water and 100-500 parts by weight of thermally conductive filler into a mixing device and mix them.
[0015] Preferably, the step of attaching the thermally conductive paste to the fiberglass cloth and curing it to form a thermally conductive colloid includes:
[0016] The fiberglass cloth is immersed in the thermally conductive slurry and then removed.
[0017] Scrape off any excess thermally conductive paste from the surface of the fiberglass cloth;
[0018] The fiberglass cloth with the thermally conductive paste attached is baked to solidify the thermally conductive paste into the thermally conductive colloid.
[0019] The fiberglass cloth with the thermally conductive colloid attached is leveled.
[0020] Preferably, the step of scraping off excess thermally conductive paste from the surface of the fiberglass cloth includes:
[0021] The fiberglass cloth with the thermally conductive paste attached is passed through a comma-shaped scraper.
[0022] Preferably, the preset thickness is 0.035-0.27 mm.
[0023] A high-temperature resistant thermally conductive insulating sheet prepared according to any one of the above methods comprises: fiberglass cloth and the thermally conductive colloid attached to the fiberglass cloth; the fiberglass cloth has pores; the thermally conductive colloid permeates into the pores.
[0024] This application has the following advantages:
[0025] In the embodiments of this application, in response to the problem that existing thermally conductive insulating sheets cannot withstand temperatures exceeding 200°C over long periods, this application provides a solution using fiberglass cloth as the substrate and polytetrafluoroethylene (PTFE) as the continuous phase filled with thermally conductive powder. Specifically, the solution involves: mixing 100 parts by weight of PTFE emulsion, 10-300 parts by weight of plasticizer, 0-30 parts by weight of water, and 100-500 parts by weight of thermally conductive filler to obtain a thermally conductive slurry; continuously attaching the thermally conductive slurry to fiberglass cloth and curing it to form a thermally conductive colloid until the thickness of the fiberglass cloth with the thermally conductive colloid reaches a preset thickness, thereby obtaining a high-temperature resistant thermally conductive insulating sheet roll; and cutting the high-temperature resistant thermally conductive insulating sheet roll to obtain a high-temperature resistant thermally conductive insulating sheet. By using polytetrafluoroethylene (PTFE) as a carrier, long-term temperature resistance exceeding 250°C can be achieved. By adding plasticizers, the creep effect of PTFE is intensified, making the product more prone to creep under stress, which can achieve a low interfacial thermal resistance, with a minimum thermal resistance of less than 0.3°C-in² / W (@50psi). Attached Figure Description
[0026] To more clearly illustrate the technical solution of this application, the drawings used in the description of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0027] Figure 1 This is a flowchart illustrating the steps of a method for preparing a high-temperature resistant thermally conductive insulating sheet according to an embodiment of this application;
[0028] Figure 2 This is a photograph of a high-temperature resistant thermally conductive insulating sheet provided in one embodiment of this application. Detailed Implementation
[0029] To make the objectives, features, and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0030] Reference Figure 1 In one embodiment of this application, a method for preparing a high-temperature resistant thermally conductive insulating sheet is provided, comprising:
[0031] S110. Mix 100 parts by weight of polytetrafluoroethylene emulsion, 10-300 parts by weight of plasticizer, 0-30 parts by weight of water and 100-500 parts by weight of thermally conductive filler to obtain thermally conductive slurry.
[0032] S120. The thermally conductive paste is continuously applied to the fiberglass cloth and cured to form a thermally conductive colloid until the thickness of the fiberglass cloth with the thermally conductive colloid reaches the preset thickness, thereby obtaining a high-temperature resistant thermally conductive insulating sheet roll.
[0033] S130. Cut the high-temperature resistant thermally conductive insulating sheet roll to obtain a high-temperature resistant thermally conductive insulating sheet.
[0034] In the embodiments of this application, in response to the problem that existing thermally conductive insulating sheets cannot withstand temperatures exceeding 200°C over long periods, this application provides a solution using fiberglass cloth as the substrate and polytetrafluoroethylene (PTFE) as the continuous phase filled with thermally conductive powder. Specifically, the solution involves: mixing 100 parts by weight of PTFE emulsion, 10-300 parts by weight of plasticizer, 0-30 parts by weight of water, and 100-500 parts by weight of thermally conductive filler to obtain a thermally conductive slurry; continuously attaching the thermally conductive slurry to fiberglass cloth and curing it to form a thermally conductive colloid until the thickness of the fiberglass cloth with the thermally conductive colloid reaches a preset thickness, thereby obtaining a high-temperature resistant thermally conductive insulating sheet roll; and cutting the high-temperature resistant thermally conductive insulating sheet roll to obtain a high-temperature resistant thermally conductive insulating sheet. By using polytetrafluoroethylene (PTFE) as a carrier, long-term temperature resistance exceeding 250°C can be achieved. By adding plasticizers, the creep effect of PTFE is intensified, making the product more prone to creep under stress, which can achieve a low interfacial thermal resistance, with a minimum thermal resistance of less than 0.3°C-in² / W (@50psi).
[0035] The following will further explain a method for preparing a high-temperature resistant thermally conductive insulating sheet in this exemplary embodiment.
[0036] As described in step S110, 100 parts by weight of polytetrafluoroethylene emulsion, 10-300 parts by weight of plasticizer, 0-30 parts by weight of water and 100-500 parts by weight of thermally conductive filler are mixed to obtain a thermally conductive slurry.
[0037] 100 parts by weight of polytetrafluoroethylene emulsion, 10-300 parts by weight of plasticizer, 0-30 parts by weight of water and 100-500 parts by weight of thermally conductive filler are added to a mixing device (e.g., a double planetary mixer) and mixed to obtain a thermally conductive slurry.
[0038] Specifically, the polytetrafluoroethylene (PTFE) emulsion is an aqueous dispersion formed by concentrating the dispersion of polymerized PTFE to approximately 60 wt% PTFE solids and stabilizing it with a nonionic surfactant. By mass, it comprises: 55-65 parts PTFE, 25-35 parts nonionic surfactant, and 5-15 parts water. The plasticizer is a perfluoroalkane with 16-30 carbon atoms, such as at least one of perfluorohexadecane and perfluoroeicosane. The water is distilled water, used to adjust the viscosity of the thermally conductive slurry. The thermally conductive filler is a white powder formed by mixing alumina and boron nitride of different particle sizes.
[0039] As described in step S120, the thermally conductive paste is continuously applied to the fiberglass cloth and cured to form a thermally conductive colloid until the thickness of the fiberglass cloth with the thermally conductive colloid reaches a preset thickness, thereby obtaining a high-temperature resistant thermally conductive insulating sheet roll.
[0040] The following operations are performed continuously until the thickness of the fiberglass cloth with the thermally conductive colloid reaches the preset thickness, resulting in a high-temperature resistant thermally conductive insulating sheet roll: the fiberglass cloth is immersed in the thermally conductive slurry and then removed; excess thermally conductive slurry is scraped off from the surface of the fiberglass cloth; the fiberglass cloth with the thermally conductive slurry is baked to solidify the thermally conductive slurry into the thermally conductive colloid; and the fiberglass cloth with the thermally conductive colloid is smoothed.
[0041] Specifically, the preset thickness is 0.035-0.27mm, preferably 0.25±0.02mm, 0.038±0.03mm, or 0.05±0.03mm.
[0042] As described in step S130, the high-temperature resistant thermally conductive insulating sheet roll is cut to obtain a high-temperature resistant thermally conductive insulating sheet.
[0043] The high-temperature resistant thermally conductive insulating sheet roll is trimmed, wound up, and die-cut to obtain the high-temperature resistant thermally conductive insulating sheet.
[0044] In one embodiment of this application, the specific process of "attaching the thermally conductive paste to the fiberglass cloth and curing it to form a thermally conductive colloid" can be further described in conjunction with the following description.
[0045] The fiberglass cloth is immersed in the thermally conductive slurry and then removed, or the thermally conductive slurry is coated on the surface of the fiberglass cloth so that the thermally conductive slurry fully penetrates the pores of the fiberglass cloth.
[0046] Excess thermally conductive paste is scraped off the surface of the fiberglass cloth. Specifically, the fiberglass cloth with the thermally conductive paste is pulled through a comma-shaped scraper using a traction device; the scraper spacing of the comma-shaped scraper is 0.05-0.5 mm.
[0047] The fiberglass cloth coated with the thermally conductive paste is baked to solidify the thermally conductive paste into the thermally conductive colloid. Specifically, the fiberglass cloth coated with the thermally conductive paste is passed through a high-temperature oven using a traction device, causing the moisture in the thermally conductive paste to evaporate and the resin to melt, thus forming the thermally conductive colloid.
[0048] The fiberglass cloth with the thermally conductive colloid attached is leveled. Specifically, the fiberglass cloth with the thermally conductive colloid attached is passed through a pair of smooth leveling rollers using a traction device to flatten the surface of the fiberglass cloth with the thermally conductive colloid attached.
[0049] Reference Figure 2 In one embodiment of this application, a high-temperature resistant thermally conductive insulating sheet prepared according to the preparation method described in any of the above embodiments is also provided, comprising: fiberglass cloth and the thermally conductive colloid attached to the fiberglass cloth; the fiberglass cloth is provided with pores; the thermally conductive colloid permeates into the pores.
[0050] In the embodiments of this application, in response to the problem that existing thermally conductive insulating sheets cannot withstand temperatures exceeding 200°C for extended periods, this application provides a solution using fiberglass cloth as the substrate and polytetrafluoroethylene (PTFE) as the continuous phase filled with thermally conductive powder. Specifically, it is described as: "A high-temperature resistant thermally conductive insulating sheet, comprising: fiberglass cloth and the thermally conductive colloid attached to the fiberglass cloth; the fiberglass cloth has pores; the thermally conductive colloid permeates into the pores." By using PTFE as a carrier, long-term temperature resistance exceeding 250°C can be achieved. By adding plasticizers, the creep effect of PTFE is intensified, making the product more prone to creep under stress, thus achieving a lower interfacial thermal resistance, with a minimum thermal resistance of less than 0.3°C-in² / W (@50psi).
[0051] The following are specific embodiments of this application:
[0052] Example 1:
[0053] A high-temperature resistant thermally conductive insulating sheet.
[0054] The high-temperature resistant thermally conductive insulating sheet is prepared by the following method:
[0055] 100 parts by weight of polytetrafluoroethylene emulsion, 100 parts by weight of perfluoroeicosane, 20 parts by weight of water and 200 parts by weight of alumina powder are mixed to obtain a thermally conductive slurry.
[0056] The thermally conductive paste is continuously applied to the fiberglass cloth and cured to form a thermally conductive colloid until the thickness of the fiberglass cloth with the thermally conductive colloid reaches 0.23 mm, thus obtaining a high-temperature resistant thermally conductive insulating sheet roll.
[0057] The high-temperature resistant thermally conductive insulating sheet roll is cut to obtain the high-temperature resistant thermally conductive insulating sheet.
[0058] Example 2:
[0059] A high-temperature resistant thermally conductive insulating sheet.
[0060] The high-temperature resistant thermally conductive insulating sheet is prepared by the following method:
[0061] 100 parts by weight of polytetrafluoroethylene emulsion, 10 parts by weight of perfluorohexadecane, 10 parts by weight of water and 100 parts by weight of boron nitride powder are mixed to obtain a thermally conductive slurry.
[0062] The thermally conductive paste is continuously applied to the fiberglass cloth and cured to form a thermally conductive colloid until the thickness of the fiberglass cloth with the thermally conductive colloid reaches 0.22 mm, thus obtaining a high-temperature resistant thermally conductive insulating sheet roll.
[0063] The high-temperature resistant thermally conductive insulating sheet roll is cut to obtain the high-temperature resistant thermally conductive insulating sheet.
[0064] Example 3:
[0065] A high-temperature resistant thermally conductive insulating sheet.
[0066] The high-temperature resistant thermally conductive insulating sheet is prepared by the following method:
[0067] 100 parts by weight of polytetrafluoroethylene emulsion, 150 parts by weight of perfluorohexadecane, 150 parts by weight of perfluoroeicosane, 30 parts by weight of water, 250 parts by weight of alumina and 250 parts by weight of boron nitride powder are mixed to obtain a thermally conductive slurry.
[0068] The thermally conductive paste is continuously applied to the fiberglass cloth and cured to form a thermally conductive colloid until the thickness of the fiberglass cloth with the thermally conductive colloid reaches 0.24 mm, thus obtaining a high-temperature resistant thermally conductive insulating sheet roll.
[0069] The high-temperature resistant thermally conductive insulating sheet roll is cut to obtain the high-temperature resistant thermally conductive insulating sheet.
[0070] Comparative Example 1
[0071] Standard thermally conductive insulating sheet (product model TC900S1).
[0072] Comparative Example 2
[0073] Standard thermally conductive insulating sheet (product model TC1200).
[0074] The thickness, hardness, thermal resistance, and anti-sagging performance at 250°C of Examples 1, 2, and 3 and Comparative Examples 1 and 2 were tested respectively. The test results are shown in Table 1.
[0075]
[0076] Table 1. Performance test results of the embodiments and comparative examples.
[0077] As shown in Table 1, the high-temperature resistant thermally conductive insulating sheet prepared by the preparation method provided in this application not only has a low interfacial thermal resistance, but can also withstand temperatures exceeding 250°C for a long period of time.
[0078] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.
[0079] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.
[0080] The preparation method of a high-temperature resistant thermally conductive insulating sheet and the high-temperature resistant thermally conductive insulating sheet provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A method for preparing a high-temperature resistant thermally conductive insulating sheet, characterized in that, include: A thermally conductive slurry is obtained by mixing 100 parts by weight of polytetrafluoroethylene emulsion, 10-300 parts by weight of plasticizer, 0-30 parts by weight of water and 100-500 parts by weight of thermally conductive filler; the plasticizer includes perfluoroalkane with 16-30 carbon atoms. The thermally conductive paste is continuously applied to the fiberglass cloth and cured to form a thermally conductive colloid until the thickness of the fiberglass cloth with the thermally conductive colloid reaches the preset thickness, thereby obtaining a high-temperature resistant thermally conductive insulating sheet roll. The high-temperature resistant thermally conductive insulating sheet roll is cut to obtain a high-temperature resistant thermally conductive insulating sheet.
2. The preparation method according to claim 1, characterized in that, The polytetrafluoroethylene emulsion comprises, by weight, 55-65 parts polytetrafluoroethylene, 25-35 parts nonionic surfactant, and 5-15 parts water.
3. The preparation method according to claim 1, characterized in that, The plasticizer includes at least one of perfluorohexadecane and perfluoroeicosane.
4. The preparation method according to claim 1, characterized in that, The thermally conductive filler includes at least one of alumina and boron nitride.
5. The preparation method according to claim 1, characterized in that, The step of mixing 100 parts by weight of polytetrafluoroethylene emulsion, 10-300 parts by weight of plasticizer, 0-30 parts by weight of water, and 100-500 parts by weight of thermally conductive filler includes: Add 100 parts by weight of polytetrafluoroethylene emulsion, 10-300 parts by weight of plasticizer, 0-30 parts by weight of water and 100-500 parts by weight of thermally conductive filler into a mixing device and mix them.
6. The preparation method according to claim 1, characterized in that, The step of attaching the thermally conductive paste to the fiberglass cloth and curing it to form a thermally conductive colloid includes: The fiberglass cloth is immersed in the thermally conductive slurry and then removed. Scrape off any excess thermally conductive paste from the surface of the fiberglass cloth; The fiberglass cloth with the thermally conductive paste attached is baked to solidify the thermally conductive paste into the thermally conductive colloid. The fiberglass cloth with the thermally conductive colloid attached is leveled.
7. The preparation method according to claim 6, characterized in that, The step of scraping off excess thermally conductive paste from the surface of the fiberglass cloth includes: The fiberglass cloth with the thermally conductive paste attached is passed through a comma-shaped scraper.
8. The preparation method according to claim 1, characterized in that, The preset thickness is 0.035-0.27mm.
9. A high-temperature resistant thermally conductive insulating sheet prepared by the preparation method according to any one of claims 1-8, characterized in that, include: Fiberglass cloth and the thermally conductive colloid attached to the fiberglass cloth; The fiberglass cloth has pores; The thermally conductive colloid permeates into the pores.