Heat-Depolymerizable Tethers for Microelectromechanical System Assembly

Microelectromechanical systems (MEMS) assembly into packages that interface with the environment is critical in electronic sensor applications ranging from soft biomedical systems to telecommunications. This article presents a novel process using heat-depolymerizable polyethylene carbonate (QPAC-25) as a sacrificial tether, and demonstrates it for assembling wafer-bound MEMS onto wires. The assembly mechanism is thermal removal of the tether, allowing a strained layer to pop up from the substrate and make electrical and mechanical contact with the wire. We detail the QPAC-25 fabrication procedures, characterize the relationship between QPAC-25 thickness and spin speed and determine a route to pattern QPAC-25 without a metal hard mask or photosensitizers.[2024-0157]