This research shows the electrical characteristic using excellent epoxy nano-composite of MgO 5.0 wt% and SiO2 0.4 wt% in mechanical strength test depending on nano-additive. First of all, volume resistance depending on nano-additive and temperature using high resistance meter (HP. 4329A) by increasing 10, 100, 1,000 V of applying voltage was measured. Moreover, temperature range of 25~120℃ with virgin sample was tested using TO-9B oven by Ando Company. The result showed that virgin and the samples added with MgO and SiO2 had similar value of volume resistance in low temperature and low electric field region and reduced with slow slope. The nano-composite`s volume resistance of sample added with MgO and SiO2 had higher value than virgin sample`s volume resistance in high temperature region more than 80℃. Moreover, the slope has steeply reduced. The volume resistance of sample added with MgO 5.0 wt% was 8.38×10(13) Ω·cm and it was 6.8 times more than virgin sample in high temperature at 120℃. The insulation characteristics were constant although filler has changed in low temperature region. But, in high temperature region, the value of volume resistance of sample with MgO 5.0 wt% was 7.6 times more than the virgin sample`s volume resistance.
