Thermally Conductive impedance of material will be reduced as the use time, which is about 10-15% will be changed. At last, it will get a stable value of Thermally Conductive impedance. 
       Breakdown voltage of material will be affected by humility and temperature. In order to ensure the insulation performance, 30-40% of the overmeasure is proposed.      
       When it was exposed in the chlorinated solvent and during cleaning of removing flux, it won't affect the Thermally Conductive performance, insulation performance. This material has a special stability.