Microscale Electrical Contacts for Self-Assembly

An experimental study of self-assembly processes in which small, heterogeneous components become spontaneously aligned with each other and bonded through soldering of mating electrical contacts was performed to determine and, to the extent possible, to extend the lower limits of, contact sizes for which such processes can be utilized successfully. The issue of self-assembly arises because advances in microelectronic circuitry and microelectromechanical systems pose significant challenges in the construction of threedimensional structures and the building of integrated systems made of parts from incompatible microfabrication processes. Although robotic “pick-and-place” techniques are now used to integrate parts made by different processes, the ability to efficiently handle individual parts diminishes as their sizes decrease below about 300 μm. Self-assembly is attractive as an alternative means of integrating smaller parts into structures.