Published online by Cambridge University Press: 11 February 2011
Micromolding is a recently developed technique for fabricating parts in the millimeter size range with minimum features and dimensional tolerances less than 10 μm. This degree of precision is achieved by fabricating a master using the LiGA process. The molds made from the master are then filled with powder of the desired material to form parts that are then released from the mold and sintered to high density. Currently, molds are made of either poly(methyl)methacrylate (PMMA) or poly(dimethylsiloxane) (silicone rubber, PDMS). The PMMA molds must be dissolved to release the parts using a solvent that limits the choice of binder used to hold together the powder in the part. The PDMS molds are soft and therefore not suitable for lapping the parts prior to removal from the mold. Recently, two new types of molds materials have been investigated that can be removed utilizing a phase change, either melting or sublimation. The development of these new mold materials, which allow a wider choice of binders, will be described.