Modeling of high-frequency characteristics for epoxy-sealed micro vacuum capacitors

The high-frequency loss tangent of micro vacuum dielectric capacitors (VDCs) is modeled based on the experimental results using equivalent circuit approach. We found that the dielectric loss of the capacitor at high frequency mainly arises from the dielectric loss of the periphery sealant for the capacitors. Meanwhile, the resonant frequency of the VDCs also depends on that of the sealant. However, within the constraint of sealant material, the characteristics of the VDC can still be optimized by properly choosing the geometric factors. Smaller value of the width of boundary sealant layer to the capacitor side length ratio will result in a smaller value of loss tangent.