A NOVEL WAFER-LEVEL PACKAGING SOLUTION FOR MEMS

Abstract

In this paper, a novel wafer level packaging solution for microelectromechanical system (MEMS) device is reported. Microfabrication processes were developed and integrated to facilitate such wafer-level implementation, which will lead to potential cost reduction in MEMS packaging. A sandwiched architecture was utilised to package MEMS devices at wafer level. The MEMS wafer was sandwiched between a glass cap wafer and a rerouting silicon wafer. The wafer level packaging processes include wafer thinning, etching shallow trenches, delineate gold traces on one side, and opening of through holes by anisotropic etching from the opposing side. The whole process flow prior to dicing was implemented at wafer level and was demonstrated in the packaging of pressure sensor and other MEMS test structures. Vacuum sealing was also demonstrated by wafer-level thin film coating of non-evaporable getter (NEG) for specific MEMS applications.