| Using the surface tension of molten solder to assemble micro-sized structures or micro-electro-mechanical systems (MEMS), otherwise known as “solder self-assembly” is a recent development. Complex three-dimensional assemblies, previously not realizable, can now be realized using surface micromachined MEMS and solder assembly. Not only can complex or non-complex assemblies be realized using solder self-assembly, but realized by adopting means already established commercially for mass production.; This work is the first in the world to quantify or address the known entirety of major issues that go into realizing multiple joint solder self-assembled polysilicon surface micromachined MEMS. An assembly process for multiple joint solder self-assembled MEMS is developed with a yield of 94.3%. Chemical, temperature, and timing issues are detailed for the assembly process. Guidelines on the proper design of hinges, solder pads, and connecting structures for multiple joint solder self-assembled MEMS are developed. 259 two joint test structures were designed, assembled, and measured. An assembly model of series connected n-solder joint, microstructures is developed. The experimental results are compared to the model predictions.; Worst-case and statistical tolerance analysis techniques are used to predict and quantify the probabilistic nature of the variation of assembly position of multiple joint solder self-assembled MEMS. It is found that the impact in variation of assembly position, from greatest to least, comes from solder volume variation, scavenging and overwetting, residual stress in bilayer structures, temperature, structure dimension, solder pad warpage, hinge play, and polysilicon residual stress. Guidelines on increasing the precision of assemblies are given.; Several novel examples of multiple joint solder self-assembled MEMS devices and accessories are developed. These novel examples, each projects in their own right, are solder self-assembled microrobot legs, resistive point heaters, an axial flow fan, fiber optic cable gripper, electrostatic switches, and micro containers.; This work will serve as a template or starting point in the design and manufacture of future complex solder self-assembled MEMS. This work is essential for product control and design feasibility determination in current MEMS research and the future commercialization of complex solder self-assembled MEMS. |
