UV-LIGA fabrication of microscale two-level mold inserts for MEMS applications

Abstract

Techniques for fabricating high-aspect-ratio microscale structures (HARMS) are being investigated for wide-ranging applications. Microdevices employing metal-based HARMS are of particular interest for mechanical, electro-mechanical, and chemical applications. In many applications, HARMS with two or several distinct heights are necessary, the fabrication of which necessitates two-level or multi-level mold inserts. In addition, tapered mold inserts would help achieving easy insert-part separation. Here we report a process for fabricating two-level, tapered mold inserts by combining UVlithography on SU-8 resist, one-step metal electrodeposition, polish and level, and SU-8 resist removal. Without tilt and rotation during the lithography process, tapered SU-8 plating molds are obtained by employing light diffraction during lithography and proper development procedures. The SU-8 resist removal process does not reduce its strength. Efficacy of this approach is demonstrated with a two-level insert prototype suitable for fabricating micro heat exchanger parts by compression micromolding.

The Characteristics of Fluid Flow and Heat Transfer in Wavy, Dimple and Wavy-Dimple Microchannels

“…With the development of electronic technology, the power density of the electronic device also increases rapidly, and chip high heat flux has become the bottleneck of the further development of integrated circuits. Research shows that more than 55% failures of the electronic device is caused by high temperature [1], so how to cool the chip effectively has become one of the important subject for the development of information industry. In the field of chip cooling, micro channel cooling has become the research focus all over the world [2], as well as an advanced mode of cooling.…”