Micro-metalforming with silicon dies

The introduction of forming technology into MEMS manufacturing demands forming dies being characterized by a high strength and hardness, a good micro-structurability, a low surface roughness, and a high precision of the microgeometry to be molded. Silicon structured by lithography and etching processes meeting these requirements especially concerning precision and surface roughness. For micro-metalforming silicon dies with different structural dimensions (>1 mum) have been used. The microstructures could be molded in different materials using cold and superplastic embossing. The precision and surface quality of the formed parts correspond to the high quality of the microstructured die. Both the low surface roughness and the accurate edges of the silicon structures are nearly represented in the molded structures. However, in particular during cold embossing die wear or even die failure could be observed limiting the implementation of silicon for micro-metalforming.