Metal micromolding with surface engineered inserts

The LiGA (Lithographic, Galvanoformung, Abformung) technique is a leading micromanufacturing process for making polymer- and metal- based high-aspect-ratio microscale structures. Molding replication is the key LiGA step for economical mass production of metal-based HARMS. Using a hybrid technique, we have fabricated microscale Ta mold inserts. Surface engineering of Ta inserts by electrochemical polishing followed by conformal coating deposition has enabled successful high-temperature micromolding of Al and Cu. In this paper, the molding performance of Ta inserts coated with amorphous hydrogenated carbon based coatings and amorphous silicon nitride based coatings is compared. Issues of maximum molding force, demolding force, and coating durability are addressed.