High-Accuracy Bulk Metallic Glass Mold Insert for Hot Embossing of Complex Polymer Optical Devices

Metallic glasses (MGs) have been reported to be excellent mold insert materials for hot embossing of polymers, but limited by the simple shape of the embossed polymer devices and the high cost resulted by the application of Pt- and Pd-based MGs. The development of inexpensive MG mold inserts with complex shape as well as high accuracy is of great importance. In present work, polymethylmethacrylate optic devices with complex micro structures and excellent grating performance have been hot embossed precisely by using newly developed centimeter-sized Ni62Pd19Si2P17 MG molds. The Ni62Pd19Si2P17 MG exhibits high fracture strength of 1840 MPa, distinctive plastic strain of 4% and high thermal-stability. The die imprinted MG microstructures exhibit very low linear shrinkage (0.002 mu m) and relative linear shrinkage rate (0.033%). It indicates that the Ni62Pd19Si2P17 MG could serve as inexpensive and durable mold inserts for precise embossing of polymer micro devices in large scale. (C) 2015 Wiley Periodicals, Inc.