Low-viscosity high-heat-conductivity organic silicon electronic pouring sealant and preparation method thereof

Abstract

The invention provides low-viscosity high-heat-conductivity organic silicon electronic pouring sealant and a preparation method thereof. The method comprises the following steps of: mixing high viscosity and low viscosity of vinyl polydimethylsiloxane; adding aluminum oxide with particle size of 1-5 microns as heat conduction filler; further adding a compound coupling agent formed by combining aluminic acid ester, KH570 (gamma-methylacryloyloxypropyl trimethoxysilane) and KH550 (gamma-aminopropyl triethoxysilane) and a compound flame retardant formed by combining melamine cyanurate and aluminum hydroxide into a base material system; and preparing the electronic pouring sealant according to a proper proportion. The prepared pouring sealant has high heat conductivity up to 2.5-3.0W.m<-1>.K<-1>, low viscosity of 2000-3000mPa.s, perfect fluidity and good flame retardance effect; and the production cost is low.

Description

technical field [0001] The invention relates to the technical field of electronic potting glue, in particular to a low-viscosity, high-thermal-conductivity organic silicon electronic potting glue and its preparation technology. Background technique [0002] High-tech fields such as electronic components, large integrated circuit boards, and LEDs are gradually achieving high performance, high reliability, and miniaturization. Excellent high and low temperature resistance, mechanical properties, electrical insulation properties, but also good thermal conductivity, flame retardancy and fluidity. Currently used potting materials such as epoxy resin, polyurethane and silicone rubber are widely used. Silicone rubber can be used as the material of choice for potting electronic and electrical assemblies because it can maintain elasticity for a long time in a wide temperature range, and has good electrical properties and chemical stability. However, typical unfilled silicone rubber...

AI Technical Summary

Problems solved by technology

However, typical unfilled silicone rubber has poor thermal conductivity, and its thermal conductivity is only 0.2W m -1 ·K -1 Left and right, used as potting glue, often leads to the heat generated by electronic equipment cannot be dissipated in time, which greatly affects the reliability and life of electronic components

[0003] At present, in terms of improving thermal conductivity, silicone rubber is generally filled with thermally conductive fillers with good insulating properties, such as alumina, silicon carbide whiskers, boron nitride, etc., but generally the amount of thermally conductive filler used is large, and the price of the filler used Expensive, and the thermal conductivity is generally difficult to break through 1.5W m -1 ·K -1 , or although electronic potting adhesives with slightly better thermal conductivity can be prepared, the viscosity tends to increase significantly, which makes the fluidity of the potting adhesives poor, which not only affects the use, but also requires a lot of energy for degassing during production.

[0004] The Chinese patent application with the publication number CN102337033A discloses an addition-type high thermal conductivity silicone electronic potting compound. The thermal conductive filler used is a mixture of spherical alumina, boron nitride, and silicon carbide whiskers. The thermal conductive filler can be used Preparation thermal conductivity 1.0W m -1 ·K -1 potting compound, but the silicon carbide whiskers and boron nitride used in this thermal filler are relatively expensive, which increases the cost

The Chinese patent application with the publication number CN101402798B discloses a kind of heat-conducting and flame-retardant liquid silicone rubber for electronics. -1 ·K -1 ), but its viscosity has reached more than 10000mPa·s, the fluidity is poor, and it is difficult to sizing

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