| Packaging poses the critical challenge for the commercialization of MEMS products. It provides structural and environmental protection for MEMS devices to enhance their reliability. Packaging is one of the most costly parts of Microsystems manufacturing, and it is often the first to fail or negatively influence the system response. It often has a detrimental effect on overall device performance. Successful development of MEMS and Microsystems requires a number of technologies for their packaging, assembly, and low-cost fabrication. The cost, long-term reliability, and yield of many MEMS devices are often dictated by packaging.;First, the thesis focuses on current MEMS packaging methods, specifically eutectic bonding technique. Gold to gold eutectic bonding is developed and applied for packaging titanium MEMS devices in both device and wafer scales. Different Ti/Pt/Au films are patterned and deposited on titanium substrates to investigate eutectic material impact on the bonding quality. The hermiticity tests on the bonded samples are shown the eutectic bonding technique has lack of reproducibility and high dependency on the process and the surface topography. The high temperature process of bonding and the films thermal mismatch are the main drawbacks of the eutectic bonding.;Second, pulsed laser welding on a titanium substrate is investigated. The laser is used as a local heating source to micro weld the titanium cap to the substrate. The physics of the pulsed laser welding is studied, and a three-dimensional time dependent model of heat flow during laser beam welding is presented. Then the model calculations are compared and calibrated with experimental results of pulsed laser welds.;Third, the pulsed laser welding is applied to package MEMS both on the device and the wafer scale. In device scale packaging, the laser parameters are investigated to determine correlation between the melt depth and the generated heat in the welding process. In wafer scale packaging, the pulse laser parameters and the geometry of the titanium wafer cap and substrate at the interface are studied to optimize the melt depth based on minimizing the heat.;Fourth, a titanium flat thermal ground plane (TGP) heat pipe for cooling semi-conductor devices is introduced. The pulsed laser welding technique is employed for packaging the TGP. The design, fabrication and packaging of the heat pipe are illustrated. |
