In this study, the electrostatic capacity and dielectric loss tangent for 20 μm thick thermal conductivity silicone rubber which is heated at 80 degrees for 8 hours has been measured at temperature of 30℃∼170℃, frequency of 0.1∼1 MHz. The results of degradation evaluation by this study are as follows. In low frequency, it found that the electrostatic capacity decreased with increasing temperature. On the other hand, it confirmed that the range of the electrostatic capacity narrowed with increasing frequency. It confirmed that there are the carboxylic acid structure and C-O bonding at range of wave number 1,000cm-1 to 1,300cm-1.

In this study, the properties of C-V degradation for thermal conductivity silicone rubber sample which is attached by copper-copper, copper-aluminum, aluminum-aluminum on upper-side and under-side has been measured at temperature of 80℃∼140℃. The results of this study are as follows. In case the frequency is increased, it found that the electrostatic capacity increased with increasing temperature to 80℃, 110℃, 140℃ regardless of kind of electrode. It found that the electrostatic capacity increased with becoming high temperature range of frequency regardless of kind of electrode. This result is considered to be caused by thermal absorption on the thermal conductivity silicone rubber sample. It found that the electrostatic capacity decreased with increasing temperature and frequency. This result is considered to be caused by molecular motion of C-F radical or OH radical.

In this study, the frequency properties of electrostatic capacity and dielectric loss for the samples with different types of filler has been measured in through the applied frequency range of 7 kHz -3,000 kHz at temperature of 80℃, 110℃, 140℃, 170℃. The results of this study are as follows. When the sample is degradated at the temperature of 80℃, 110℃, 140℃, 170℃ and the frequency range of 7 kHz -3,000 kHz is applied, It found that the electrostatic capacity of the sample with Polyimide film is larger than the sample with Grass fiber. It found that the dielectric loss for the sample with Polyimide film is larger than the sample with Grass fiber with increasing frequency and temperature in the 80℃, 110℃, 140℃, 170℃ range. Also, the dielectric loss decreased with increasing frequency. In case of the sample with Polyimide film, It found that the electrostatic capacity decreased with increasing temperature, and the dielectric loss gradually decreased with increasing frequency.

In this study, the temperature characteristics of electrostatic capacity and dielectric loss for thesample of Teflon film which is degradated at the 120℃∼200℃ temperature range in the oven for 10 hourshas been measured in through the applied frequency range of 0.1 kHz∼4,800 kHz at temperature of 50℃,90℃, 130℃, 170℃. Also, in the same conditions, the frequency characteristics of electrostatic capacity anddielectric loss for the sample of Teflon film has been measured in through the applied temperature rangeof 30℃∼70℃ on setting frequency of 0.1 kHz, 1 kHz, 10 kHz, 100 kHz. The results of this study are asfollows. When the frequency range of 0.1 kHz∼4,800 kHz applied to the sample of Teflon film, theelectrostatic capacity has been measured at the temperature of 50℃, 90℃, 130℃, 170℃. Through thismeasurement, it found that the electrostatic capacity decreased with increasing temperature. Regarding thisresult, may be it is because the electromagnetic coupling is degraded by thermal degradation. When thesample of Teflon film heated at 280℃ for 10 hours in oven, the dielectric loss has changed from unstablestatus to stabilizing status with increasing the degradation temperature in the 120℃, 160℃, 200℃ range. Inthis measurement, the two spectrums of dielectric loss appeared. It considers that this spectrum ofdielectric loss appeared in 300 Hz is caused by the molecular motion of the C-F or OH group. Throughthis study, It found that the electrostatic capacity decreased with increasing frequency and temperature,and there is no change in dielectric loss, although the frequency increases.

In this study, the moisture content, charge?discharge current, electrostatic capacity and dielectric loss tangent are measured for the specimen of bisphenol type epoxy resin which is mixed with squared amorphous silica filler and dipped in hot water of 50℃ for 169 days. The results of this study are listed below. The longer of deposition day, the charge and discharge current was increased. It is considered that the reason is because there was water attack through the squared silica surface. The longer of deposition day, the absorption rate of all specimens was increased. It found that the absorption rate reached saturated state after 100 days. The higher frequency and the longer of deposition day, the tanδ was decreased. Also, It found that the tanδ and electrostatic capacity of the specimen which is mixed with squared filler are greater.