Analysis of a Process for Replication of Electroforming Molds with Integral Microscreens

摘要

A process for the rapid replication of electroforming plastic micromolds has been developed at Sandia National Laboratories, Livermore, CA. The process is based on injection molding of plastic replicates with integral metallic screens to produce sacrificial electroforming molds in which the metallic screen acts as the conducting base and the plastic features provide insulating sidewalls. The process consists of injecting molten PMMA via a center-gate into a disk-shaped mold cavity in which a sandwich of a flow channel plate, porous Nickel foam, and metallic microscreen are placed on top of the LIGA-fabricated tooling. A numerical model for the coupled heat transfer and fluid flow phenomena is used to investigate the effects of various process parameters on the mold-filling behavior. The results from the parametric studies are presented and discussed.