Characterization of Kovar-Pyrex anodically bonded samples: a new packaging approach for MEMS devices

The ability to anodically bond Kovar to Pyrex 7740 significantly expands the packaging approaches available for MEMS devices. This technique greatly simplifies and reliably interconnects micropropulsion MEMS components (thrusters, valves) with the attached propellant system. Experimental bonds of Kovar plates and fixtures have been made to numerous Pyrex samples in order to investigate the strength and failure modes of these bonds. An emphasis on experimentally bonding at low temperatures (~200 $DEGC) using large voltages (< 2000V) was also a important parameter of this research and a current microvalve project at JPL. Bond strength measurements have been made using calibrated pull and burst tests with their results being comparable to typical silicon to Pyrex anodic bonds. Detailed bonding conditions for the tested samples have been included in this manuscript to aid the MEMS designer in using this approach to satisfy their packaging needs.