TABLE OF CONTENTS The MEMS approach offers much to improve the state-of-the-art in advanced packaging. In thermal management, for example, MEMS/micro-machining concepts ranging from surface texturing to micro-pumps can be implemented to improve the effective thermal conducting of otherwise passive heat removal structures. MEMS devices may offer clues to building better electrical connectors and smart connection systems, surpassing the current technology limitations (15 20 milli-inch pitch). For serviceability, it is conceivable that MEMS technology might provide the only way to build micro zero insertion force (ZIF) sockets. Perhaps most exciting is using MEMS technology to create a new class of smart substrates, in which the local dielectric properties and even the specific wiring configurations might be adjustable under user control.
One of the first practical thermal management concepts involving micro-machines was the so called micro-channel technology [38], which improves the effective heat removal surface area dramatically and is powerful when applied to the back surfaces of individual dies. The combination of textured surfaces and liquid cooling has been extensively studied. The group at the University of California, Los Angeles (UCLA) in particular examined the optimisation of the shape of a single surface site in silicon to promote boiling nucleation in a liquid medium to maximise thermal transport [39]. Possible mechanisations of a complete, active micromachined cooling system were studied at the Air Force Institute of Technology (AFIT) in demonstrations of a complete peristaltic pumping system embedded in a silicon wafer. Several Air Force Research Laboratory (AFRL)...
