Polymer replication is a prerequisite for low-cost microstructure components for consumer and end user market. The production of cost-effective microstructure in polymers requires metal molding tools which are often fabricated by direct structuring methods like milling or laser machining both of which are time-consuming and cost-intensive. We present an alternative fabrication method based on replication processes which allows the cheap (∼ 50 €) and fast (∼ 12 h) replication of complex microstructures into metal. The process comprises three steps: 1. Generation of the microstructure in a photoresist via lithography. 2. Casting of the structure into a high-temperature silicone which serves as original mold for creation of the metal molding tool. 3. Melting of an eutectic alloy of Sn, Ag and Cu under light pressure directly inside of the silicone within an oven. After cooling to room temperature the metal molding tool can be used for polymer replication into conventional thermoplastic polymers. As a first example we structured polymethylmethacrylate (PMMA) foils with a thickness of 1 mm via hot embossing and feature sizes of 100 μm could be replicated with high fidelity.

Date Published: 28 February 2017
PDF: 6 pages
Proc. SPIE 10061, Microfluidics, BioMEMS, and Medical Microsystems XV, 100610D (28 February 2017); doi: 10.1117/12.2249831

Published in SPIE Proceedings Vol. 10061:
Microfluidics, BioMEMS, and Medical Microsystems XV
Bonnie L. Gray; Holger Becker, Editor(s)