Fabrication of membrane-typed metal mould with microstructures and application for roller imprinting

In this paper, we focus on the development of membrane-typed metal mould with microstructures for imprinting. This mould has several benefits including reusable, easy replaceable core, and low cost that strongly improves industrial values in microstructure mass production. The membrane-typed metal mould with a thickness of 60 μm can be attached to a level mould or a roller mould, and becomes a metal core for the polymer microstructure imprint for mass production of products over large surface area. Photolithography, electroforming, and grinding techniques have been integrated in order to develop the membrane-typed metal mould in this research. It has been proven that the metal mould of micro pillars could be successfully fabricated. This metal mould was fabricated by precision electroforming technology that Ni-Co alloy was deposited on a photoresist mould, and further peeled off to attach onto a level mould. The hardness, stiffness and toughness of the Ni-Co alloy material core structure were sufficient and strong enough for reusable duration. The durability of this membrane-typed metal mould has been greatly enhanced. Furthermore, by applying roller assisted attaching mechanism, the interface between the mould and Ni-Co alloy core became more inseparable and flat. According to the experimental measurement results, the uniformity has been controlled between ± 5 μm. The reproducing accuracy of the polymer microstructures can also be effectively enhanced.