Microscale compression molding of Al with surface engineered LiGA inserts

High temperature compression molding of Al plates with high-aspect-ratio microscale mold inserts was carried out. The bulk of the mold insert consists of electrodeposited Ni, fabricated with the LiGA (Lithographie, Galvanoformung, Abformung) technique. Both as-fabricated Ni inserts and Ni inserts conformally coated with a Ti-containing hydrocarbon (Ti-C:H) coating were used for Al micromolding at temperatures ∼450 °C. In-situ measurements of compression molding force, demolding force, and insert displacement were carried out. Insert conditions and microscale features generated on Al plates by molding were examined. Our results show that as-fabricated Ni inserts are not suitable for Al micromolding, and that Ni inserts conformally coated with a Ti-C:H coating allow repeated Al micromolding with 100% transfer of microscale features from the insert to the molded Al plate. Our results demonstrate, to our knowledge for the first time, successful replication of high-aspect-ratio Al microscale structures by high temperature compression micromolding.