Glass frit as a hermetic joining layer in laser based joining of miniature devices

In this paper, we investigate the feasibility of using a laser as the heat source to drive a hermetic joining process based on a glass frit intermediate layer. The laser allows the necessary heat energy to be provided in a localized manner; important either as part of a multistage process, or to allow thermally-sensitive materials to be used inside the package. Our study includes an investigation of the impact of rough and grooved surfaces on the hermeticity and strength of the join, demonstrating the robust nature of the process, and its ability to allow feed-throughs to the center of package. Hermetic sealing is demonstrated, with leak rates of 10^-9 mbar l s^-1, satisfying the military standard MIL-STD-883G.