Thermal grease is a kind of high thermal conductive insulation silicone material, used to fill the gap between the CPU and heat sink. Its function is used as a material to dissipate heat from CPU, make CPU temperature keep in a stable range, avoid damage of too high temperature and prolong service life. Thermal grease which filled with spherical alumina has good electrical insulation, excellent thermal conductivity, at the same time, with low oil bleeding thermal shock resistance, water repellence, ozone and weathering resistance. And almost not curing, can be used between 50 ℃ to 230 ℃ temperature over a long period. It is an ideal heat conduction material for electronic units.