Replication of LIGA structures using microcasting

Microcasting with a gold base alloy and an Al-bronze as a replication technique for LIGA structures is shown. A LIGA mold insert for injection molding is used to produce PMMA patterns as lost wax models in the microcasting process. Although there are several steps of replication the accuracy of the process is high and allows the fast manufacturing of middle size batches of microstructured parts. The mechanical properties can be varied within a wide range by choosing different casting alloys or cooling rates. Additionally the influence of the investment on the surface roughness is presented as well as results of flowlength tests showing maximal achievable aspect ratios with the gold base alloy and the Al-bronze.The funding of this work within Collaborative Research Center SFB 499 by Deutsche Forschungsgemeinschaft (DFG) is gratefully acknowledged. Thanks also to the colleagues in the SFB 499 for good collaboration, especially to S. Rath for providing special investments for microcasting.