A Systematical Method to Determine the Internal Pressure and Hermeticity of MEMS Packages

Several classes of microelectromechanical systems are sensitive to pressure and need hermetic packages to keep the internal pressure constant over their lifetime. From a functionality and reliability point of view, knowing the internal pressure and its stability over time, i.e., the hermeticity of the package, is important. This paper demonstrates a new systematical method to measure the internal pressure of the package and, in addition, its leakage rate. It is based on an innovative use of the focused ion beam together with a measurement of pressure sensitive parameters.