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CN-121991540-A - High-temperature-resistant insulating heat-conducting ceramic coating, preparation method and application thereof

CN121991540ACN 121991540 ACN121991540 ACN 121991540ACN-121991540-A

Abstract

The invention provides a high-temperature-resistant insulating heat-conducting ceramic coating, a preparation method and application thereof. The high-temperature-resistant insulating heat-conducting ceramic coating comprises, by weight, 30-40 parts of a high-temperature-resistant ceramic resin matrix, 50-70 parts of a composite ceramic functional filler, 0.5-3 parts of an auxiliary agent and a solvent. The high-temperature-resistant insulating heat-conducting ceramic coating has good performances in the aspects of temperature resistance, insulativity, heat conductivity, fire resistance and adhesive force through detection, wherein the performances are 1, namely, the heat conductivity coefficient (laser flash method) is 13W/m.K, 2, the insulating strength is 48 kV/mm, 3, the adhesive force (cross-cut method) is 1 grade, 4, the corrosion resistance is neutral salt spray test for 1000 hours, and 5, the fire resistance is fire resistance grade A1.

Inventors

  • DENG HONGLUN
  • DENG LINTAO

Assignees

  • 苏州太泷新材料科技有限公司

Dates

Publication Date
20260508
Application Date
20260319

Claims (9)

  1. 1. The high-temperature-resistant insulating heat-conducting ceramic coating is characterized by comprising the following components in parts by weight: 30-40 parts of high-temperature-resistant ceramic resin matrix; 50-70 parts of composite ceramic functional filler; 0.5-3 parts of auxiliary agent; The addition amount of the solvent is based on the viscosity of 500-2000 cP of the high-temperature-resistant insulating heat-conducting ceramic coating; the high-temperature resistant ceramic resin matrix is ceramic resin resistant to 1200 ℃; The composite ceramic functional filler comprises 20-40 parts of main heat conducting filler, 30-50 parts of auxiliary heat conducting filler and 5-10 parts of interface reinforcing filler in parts by weight; The main heat filler comprises boron nitride and/or aluminum nitride, the auxiliary heat conducting filler comprises aluminum oxide and/or magnesium oxide, the interface reinforcing filler comprises silicon micro powder and/or mica powder subjected to surface treatment of a silane coupling agent, and the auxiliary agent comprises a dispersing agent and a leveling agent.
  2. 2. The high temperature resistant insulating heat conducting ceramic paint as claimed in claim 1, wherein the high temperature resistant ceramic resin matrix is a ceramic resin resistant to 1200 ℃.
  3. 3. The high temperature resistant insulating heat conducting ceramic coating of claim 2, wherein the high temperature resistant ceramic resin matrix is a single component inorganic nano ceramic resin.
  4. 4. The high temperature resistant insulating heat conductive ceramic coating according to claim 1, wherein the dominant thermal filler particle size D50 is 10-45 μm, the auxiliary thermal filler particle size D50 is 1-10 μm, and the interface reinforcing filler particle size D50 is 1-10 μm.
  5. 5. The high-temperature-resistant insulating heat-conducting ceramic coating according to claim 1, wherein the dispersing agent comprises a high-molecular dispersing agent BYK-163 and hydrophilic fumed silica, and the leveling agent is BYK-346 leveling agent.
  6. 6. The high temperature resistant insulating heat conductive ceramic coating of claim 1, wherein the solvent comprises n-butanol and xylene.
  7. 7. The high temperature resistant insulating heat conducting ceramic coating according to claim 6, wherein the mass ratio of the n-butanol to the xylene is 4:1.
  8. 8. The method for preparing the high-temperature resistant insulating heat-conducting ceramic paint according to any one of claims 1 to 7, which is characterized by comprising the following steps: a) Mixing, namely adding the high-temperature resistant resin matrix, part of solvent and all auxiliary agents into a dispersing machine, and stirring and mixing uniformly at a low speed; b) The filler is dispersed, namely, under the stirring state, the main heat conduction filler, the auxiliary heat conduction filler and the interface reinforcing filler are sequentially added, and the rotating speed is increased after the addition is finished, so that high-speed dispersion is carried out; c) Grinding, namely transferring the mixed slurry into a sand mill for grinding and dispersing until the fineness is less than or equal to 15 mu m; d) Regulating viscosity, filtering, adding residual solvent to regulate viscosity to 500-2000 cP, and filtering with 100-200 mesh sieve to obtain the final product.
  9. 9. The use of a high temperature resistant insulating thermally conductive ceramic coating as claimed in any one of claims 1 to 7 in power devices and copper bars.

Description

High-temperature-resistant insulating heat-conducting ceramic coating, preparation method and application thereof Technical Field The invention relates to the technical field of ceramic coating, in particular to a high-temperature-resistant insulating heat-conducting ceramic coating, a preparation method and application thereof. Background With the rapid development of new energy automobiles, photovoltaics, energy storage and other industries, the power density and the heat productivity of the core power device MOSFET are increasingly increased, extremely high requirements are put on heat dissipation and insulation reliability, and the same requirements are also met when the core power device MOSFET is connected with copper bars. The thermal management at MOSFETF has the following problems: 1. the heat conduction silicone grease/silica gel is easy to age, dry and oil out at a high temperature for a long time, so that the heat conduction performance is drastically reduced, the insulating performance is unstable, and the reliability is poor. 2. Common epoxy heat-conducting insulating paint has limited temperature resistance level (usually below 180 ℃) and is easy to thermally degrade, yellow and pulverize at the peak temperature of a power device, and the protective effect is lost. 3. The ceramic plate/mica plate is mechanically fixed, so that the interface thermal resistance is large, the heat conduction efficiency is low, the assembly process is complex, gaps exist, local overheating is easy to generate, and the shock resistance is poor. 4. The existing heat-conducting ceramic coating has the defects that most schemes or emphasis on the heat conductivity of the filler but neglect the adhesive force and mechanical strength of the coating and a metal substrate, or the heat conductivity cannot meet the requirement due to insufficient filling quantity for manufacturability, and particularly, most of the heat-conducting ceramic coating is organic resin in the selection of film-forming resin, and the long-term stability and the heat resistance are insufficient. The surface treatment of copper bars, the traditional method is to sleeve a heat shrinkage tube (or PVC sleeve) outside, which has the following problems: 1. The plastic pipe is a poor conductor of heat, which can seriously obstruct the heat generated by the copper bar from radiating to the surrounding environment, thus causing heat accumulation, raising the temperature of the copper bar, further causing the reduction of the current-carrying capacity, the reduction of the mechanical strength and the hardness of the copper bar and the self insulation aging. 2. The long-term reliability and safety are poor, the plastic can age and become brittle after long-term heating, and vibration and mechanical stress can lead to abrasion and cracking of the sleeve, so that insulation failure and short circuit risks are caused. If the device is damaged and is not easy to be perceived during installation, 3. The complex shape has poor adaptability, and the sleeve cannot be perfectly attached to the special-shaped copper bar and the copper bar with terminals, bent angles or connecting points, so that gaps or wrinkles are easily generated, and the insulation and the attractiveness are affected. 4. The temperature resistance grade is poor, the temperature resistance of common PVC or polyolefin heat shrink tubes is usually below 125 ℃, and the application scene with higher temperature cannot be satisfied. In addition, the fire-proof auxiliary combustion furnace does not prevent fire, can burn itself when a fire disaster occurs, not only can boost combustion, and a large amount of toxic gas is discharged, so that the insulation effect is lost. 5. Most of the plastic products are poor in environmental protection, and production and waste treatment may be not friendly to the environment. 6. The process and the production efficiency are poor, manual cutting, sleeving and heating shrinkage are needed, the process is complex, automation is difficult, the production efficiency is low, and the cost rises along with the manual work. Therefore, there is an urgent need to develop a coating material having excellent temperature resistance, high insulation strength, high thermal conductivity, fire prevention, non-combustion, strong adhesion, and good workability in order to meet the severe requirements of power devices and copper bars for long-term reliability. Disclosure of Invention The invention aims to overcome the defects of the prior art, and provides a high-temperature resistant insulating heat-conducting ceramic coating, a preparation method and application thereof, wherein the coating is prepared by unique ceramic resin selection, multi-element filler compounding and grading optimization and scientific preparation process, the good construction property and film forming property under high filling are realized, and the final coating achieves the best balance in the aspects of tem