A New Packaging Method for Pressure Sensors by PDMS MEMS Technology

This paper proposes a novel wafer-level packaging (WLP) method at room temperature for piezoresistive pressure sensors. We use a polydimethylsiloxane (PDMS) sheet as a candidate for replacing a Pyrex glass wafer, to seal the backside V-grooved chambers of the pressure sensor chips. PDMS is a well-known material in MEMS technology recently. It is not only cheap but also has a merit of a simple process. We also fabricated piezoresistive pressure sensors, made by the same batch, with different packaging materials of Pyrex glass and PDMS sheet in the paper, respectively. The spin-coating approach is accessed to control the thickness of PDMS by applying the silicon and Teflon disks, as the supporting substrates during the formation of PDMS sheets. The sensors packaged by the PDMS room temperature bonding herein almost have the same performance as the ones packaged by the conventional anodic bonding through the real verification of pressure testing