Assaembly induced failures in thin film MEMS packages

In the growing MEMS market wafer level thin film packages can be applied to an increasing number of MEMS devices. This paper discusses the effects of common assembly processes on wafer level thin film packages. All assembly processes are discussed and the effects of the process on the structures is presented. From the assembly tests the grinding process poses the largest hazards followed by dicing, moulding, wire bonding and finally die attachment. A number of improvements related to etch holes and sealing structures are proposed to enhance the crack resistance and robustness.