Study on internal water vapor content and related military standards of hermetic package devices

Water vapor is one of the most important contaminants which caused devices failure. Internal water vapor content of hermetic package devices is closely related to the sealing performance, water absorption substances inside the package, leak plugging and other factors. The main mechanisms of leak plugging and water absorption by moisture absorbing substances are theoretically analyzed in this paper. Considering the harmfulness that result from the water absorption substances releasing moisture at high temperature, a simplified model is proposed, which is used to describe the internal water vapor content of a package with moisture absorbing substances. At last, this paper performs a study on related seal failure criterion in military standards by using two modes under different instances. A conclusion about the seal failure criterion in military standards is made when helium mass spectrometer leak detection method is used to detect the leak rate.