Low temperature epoxy bonding for wafer level MEMS packaging

In this paper, we report on a technology for wafer-level MEMS packaging with vertical via holes and low temperature bonding using a patternable B stage epoxy. We fabricated via holes for vertical feed-throughs and then applied bottom-up copper electroplating to fill the via holes. For low temperature wafer level packaging, we used B-stage epoxy bonding in the sealing line. The optimal bonding parameters were 150 degrees C and 30 min. The tensile strength was about 15 MPa. Therefore, this packaging technology can be used for low temperature wafer level packaging for many MEMS devices. (c) 2007 Elsevier B.V. All rights reserved.