Packaging MEMS Die on E-Glass Substrates

Abstract

Packaging MEMS devices is challenging, especially when the MEMS device is a sensor that requires direct exposure to and simultaneous protection from the operating environment. Because E-glass PCB laminate (FR4) is often used as a substrate for electronic components, a technique for directly integrating MEMS devices onto these substrates at the die level would be useful. This has been accomplished by attaching a bare die HMX2000 MEMS humidity sensor to an FR-4 carrier by forming a Au–Sn eutectic bond between the Au stud bumped die and tin–silver coated landings on the carrier. Prototype devices were then integrated with other electronics and environmentally evaluated. Test results indicated that this packaging technique was reliable.