AVS 54th International Symposium
    MEMS and NEMS Monday Sessions
       Session MN-MoM

Paper MN-MoM11
Fabrication of Metal-based High Aspect Ratio Microscale Structures by Compression Molding

Monday, October 15, 2007, 11:20 am, Room 615

Session: Materials Processing, Characterization and Fabrication Aspects
Presenter: J. Jiang, Louisiana State University
Authors: J. Jiang, Louisiana State University
F.H. Mei, Louisiana State University
W.J. Meng, Louisiana State University
Correspondent: Click to Email

Metal-based high aspect ratio microscale structures (HARMS) are basic building blocks for metallic microdevices such as micro heat exchangers1,2 and micro electromagnetic relays.3,4 Metallic microdevices may function better when subjected to high stresses, high temperatures, and other harsh conditions. Metal-based HARMS can be fabricated by combining X-ray/UV lithography and electrodeposition, following the Lithographie/Galvanoformung (LiG) protocol.5 Such primary HARMS made by LiG are expensive. In comparison, production of secondary HARMS by molding replication from HARMS inserts is fast and simple.5,6 We have demonstrated successful molding replication of HARMS in Pb7 Al8, and Cu.9 Molding replication of metal-based HARMS entails extensive plastic deformation within the molded metal. Understanding the mechanics of microscale compression molding is important for accurately assessing the capabilities and limitations of this technique. The present paper summarizes our results on instrumented compression molding of Pb, Al, and Cu as a function of the molding temperature. Measured molding responses are rationalized with companion elevated-temperature tensile testing of metals using a simple mechanics-based model of the micromolding process. The present results suggest that stresses on the insert during micromolding are determined primarily by the yield stress of the molded metal at the molding temperature and the frictional tractions on the insert sidewalls. Additional factors of complication during high temperature micromolding will be discussed.

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9D. M. Cao, J. Jiang, W. J. Meng, J. C. Jiang, W. Wang, Microsystem Technologies 2007, 13, 503.