Hebei Messi Biology Co., Ltd. stated that the thermal conductivity of magnesium oxide is better than that of alumina, and it can prepare rubber pads with higher thermal conductivity; its electrical properties are inferior to alumina, but it still meets the requirements of insulating rubber pads for ordinary electronic and electrical products. An excellent thermally conductive insulating rubber filler, but there are few reports on it. A flexible thermally conductive pad was prepared using mixed silicone rubber as the matrix and magnesium oxide as the thermally conductive filler, and its properties were studied.
When the amount of magnesium oxide is less than 200 parts, the thermal conductivity and tensile strength of small particle size magnesium oxide filled silicone rubber are greater than those of large particle size magnesium oxide filled silicone rubber. The tensile elongation at break is opposite to that of large particle size magnesium oxide// The thermal conductivity of silicone rubber is maximum when the combined ratio of particle size magnesium oxide is 100/100. Adding an appropriate amount of silane coupling agent is helpful to improve the thermal conductivity of silicone rubber. The optimal dosage is about 10% of the amount of large particle size magnesium oxide. 0.5%.
Generally, thermally conductive fillers are aluminum oxide or mixed particles of aluminum oxide, magnesium oxide and boron nitride, which have good thermal conductivity and insulation properties. Because it has a certain degree of flexibility, it can fit closely between power devices and heat-dissipating aluminum/copper sheets or machine casings to achieve better heat conduction and heat dissipation. It has been directly used in microprocessors, DC converters, relays, and UPS. automotive electronics, projection lamps and other electronic products. At present, the thermally conductive insulating rubber fillers that have been studied more and have good thermal conductivity and insulation properties include alumina, silicon nitride, etc.