Wafer level fabrication of hermetically sealed microcavity with robust metal interconnects for chip cooling application

This paper presents a novel wafer level fabrication of hermetically sealed microcavity and related micro-to-macro interconnects for silicon-based microfluidic system applications. The interconnects are made of electroless plated Ni and strongly bonded with a micromachined silicon microcavity using Au/Sn bond. The technique has been successfully applied for the microreaction chamber fabrication of a low powered micro-cooler proposed for power management applications in which refrigerating capability and low operating power are essential. Experimental result indicates the metal interconnect is robust enough to stand for at least 100 KPa stress. The technology can accompany not only the advantages of low manufacturing cost but also high hermeticity and mechanical reliability.