Wafer level vacuum packaging for MEMS device by solder sealing

Wafer level vacuum packaging is an emerging method to offer a hermetic cavity for MEMS devices with the smaller size and the lower cost, and is expected to be a new generation packaging technology of mass production to substitute the traditional metallic packaging and ceramic packaging. Solder bonding in a vacuum oven was employed in this work to achieve a Chip-to-Wafer (C2W) vacuum bonding for MEMS device. The results showed that the hermeticity of the samples met the requirements of MIL-STD-883. Effects of the process parameters such as the solder layer thickness, the soaking time of reflow, and the bonding pressure on bonding quality were investigated and optimized.