Porous carbon microsphere/paraffin composite thermal conductive silicone rubber TIM (thermal interface material) for LEDs and preparation method

Abstract

The invention discloses a porous carbon microsphere / paraffin composite thermal conductive silicone rubber TIM (thermal interface material) for LEDs. The porous carbon microsphere / paraffin silicone rubber composite thermal conductive TIM comprises raw materials in parts by weight as follows: 45-65 parts of a silicone rubber matrix, 18-26 parts of aluminum nitride, 15-25 parts of dopamine, 22-32 parts of a silver nitrate solution with the concentration of 20 mmol / L, 1.5-3 parts of hydroxyl silicone oil, 2-4 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, a proper amount of deionized water, a proper amount of a Tris-HCl buffer solution, 20-30 parts of a glucose solution with the concentration of 0.2 mol / L, a proper amount of acetone and 3-6 parts of paraffin. A tightly adherent polydopamine layer is formed by dopamine on the surface of aluminum nitride through oxidative polymerization, meanwhile, silver nanoparticles are supported on the surface of the polydopamine layer with which aluminum nitride is coated, silicone rubber filling and compounding are performed, the high heat conduction and heat radiation performance of the silicone rubber TIM is improved, and the TIM has good flexibility, tear strength and electric insulation property.

Description

technical field [0001] The invention belongs to the field of thermal interface materials, in particular to a porous carbon microsphere / paraffin wax composite heat-conducting silicone rubber thermal interface material for LEDs and a preparation method. Background technique [0002] With the continuous improvement of LED manufacturing and packaging technology, the power of LED is getting bigger and bigger. At present, the input power of commercialized high-power LEDs is generally above 1W, the chip area is 1mm×1mm, and the heat flux is 100W / cm 2 Above, heat dissipation requirements are very high. The heat transfer from the chip to the external environment has to pass through several interfaces. The gap between the interfaces and the warpage of the substrate will affect the bonding and local heat dissipation, forming interface thermal resistance. With the development of high-power and high-brightness LEDs, interface thermal resistance has become one of the problems in the LED...

AI Technical Summary

Problems solved by technology

Among them, the theoretical thermal conductivity of aluminum nitride high-purity single crystal can reach 320W / (m K), which has reliable electrical insulation performance, low dielectric loss and dielectric constant, and is an ideal thermal conductive filler. After absorbing moisture, it will undergo hydrolysis reaction with water to produce Al(OH) 3 It will interrupt the thermal conduction path, which will affect the transmission of phonons. Therefore, the thermal conductivity of the finished product is low. Even if the surface is treated with a silane coupling agent, it cannot guarantee that the filler surface is 100% covered.