Mechanical de-tethering technique for Silicon MEMS etched with DRIE process

Getting Micro-Electro-Mechanical Systems (MEMS) out of a wafer after fabrication processes is of great interest in testing, packaging or simply using these devices. Actual solutions require special machines like wafer dicing machines, increasing time and cost of de-tethering MEMS. This article deals with a new solution for manufacturing mechanical de-tetherable silicon MEMS. The presented solution could be done with DRIE process, already used in silicon MEMS fabrication, without additional time or cost. We are proposing a new way to create a notch on tethers linking both wafer and millimetric MEMS, especially designed to break with a specified mechanical force. A theoretical silicon fracture study, the experimental results and dimensional rules to design the tethers are presented in this article. This new technique is particularly useful for microscopic MEMS parts, and will find applications in the field of the MEMS components micro-assembly.