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Stresses During Micromolding of Metals at Elevated Temperatures: Pilot Experiments and a Simple Model

Published online by Cambridge University Press:  03 March 2011

W.J. Meng ,
D.M. Cao  and
G.B. Sinclair
W.J. Meng
Affiliation:
Mechanical Engineering Department, Louisiana State University, Baton Rouge, Louisiana 70803
D.M. Cao
Affiliation:
Mechanical Engineering Department, Louisiana State University, Baton Rouge, Louisiana 70803
G.B. Sinclair
Affiliation:
Mechanical Engineering Department, Louisiana State University, Baton Rouge, Louisiana 70803
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Abstract

The Lithographie, Galvanoformung, Abformung (LIGA) technique is important for making metal-based high-aspect-ratio microscale structures (HARMS) and microdevices derived from metal-based HARMS. Recently, molding replication of HARMS made of Pb, Zn, and Al has been demonstrated, advancing LIGA technology from the state where only polymer-based HARMS could be replicated by molding. This demonstration offers a potential means for economical fabrication of a wide variety of metal-based microdevices. Micromolding of a metal requires heating the metal to be molded to a significant fraction of its melting temperature. At high temperatures, the strength of the mold insert itself will typically decrease. The insert strength thus places a limit on the range of materials that can be molded. In this paper, micromolding and tensile experiments on Pb were carried out. A simple mechanics model of the micromolding process was developed. This model relates the stresses on the insert during micromolding primarily to the yield strength of the molded metal and frictional tractions on the sides of the insert. Reasonable agreement was obtained between the Pb experiments and the model predictions. Ramifications for other material systems are discussed.

Keywords

MetalMicroindentationMicroelectrical mechanical (MEMS)
Type
Articles
Information
Journal of Materials Research , Volume 20 , Issue 1 , January 2005 , pp. 161 - 175
Copyright
Copyright © Materials Research Society 2004

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