Roll-to-roll hot embossing of microstructures

Abstract

In this paper we present a new roll-to-roll embossing process allowing the replication of micro patterns with feature sizes down to 0.5 mu m. The embossing process can be run in 'continuous mode' as well as in 'discontinuous mode'. Continuous hot embossing is suitable for the continuous output of micro patterned structures. Discontinuous hot embossing has the advantage that it is not accompanied by waste produced during the initial hot embossing phase. This is because in 'discontinuous mode', embossing does not start before the foil has reached the target temperature. The foil rests between two parallel heating plates and foil movement and embossing starts only after the part of the foil resting between the heating plates has reached a thermal steady state. A new type of embossing master is used which is based on flexible silicon substrates. The embossing pattern with sub-mu m topographic resolution is prepared on silicon wafers by state of the art lithography and dry etching techniques. The wafers are thinned down to a thickness of 40 mu m, which guarantees the mechanical flexibility of the embossing masters. Up to 20 individual chips with a size of 20 x 20 mmA(2) were assembled on a roller. Embossing experiments with COC foils showed a good replication of the silicon master structures in the foil. The maximum depth of the embossed holes was about 70% of the master height

Rice and Butterfly Wing Effect Inspired Low Drag and Antifouling Surfaces: A Review

“…Fabricating embossed surfaces has been the subject of several studies 58,71,72 and techniques depend on the type of master mold and molding materials. Commonly, the master mold is silicon 71,73 and the molding material is polymethylmethacrylate (PMMA). 58,71,[74][75][76][77] Embossing can be used to fabricate various structures including, for example, microfluidic flow channels, 77-79 plastic microchips, 74 and moveable microstructures.…”

Roll manufacturing of polymer microfluidic devices using a roll embossing process

“…Thomas Velten et al [26] presented a new roll-to-roll embossing process allowing the replication of micro-patterns based on flexible silicon substrates with feature sizes down to 0.5 m, a maximum depth of the embossed holes equal to 70% of the master height has been obtained. It turned out that the quality of replication strongly depends on the master structures itself.…”

“…The influence of parameters such as roller temperature, applied pressure, roller speed and preheating of polymer substrate prior to embossing was also reviewed by various groups [24,26,28]. Metwally et al [29] investigated the manufacturing of flexible devices in thermoplastic polymer foils by roll embossing using micro-structured Si mould inserts produced by a combination of Deep Reactive Ion Etching (DRIE) and RIE.…”

A theoretical and experimental investigation of orthogonal slow tool servo machining of wavy microstructured patterns on precision rollers

“…Yang et al [7] proposed a method for fabricating a microstructured roller by mounting a flexible mould plate with microstructures to the periphery of a cylinder. Other common methods for fabricating a roller with microstructures are lithography and dry etching techniques [8]. Compared with other machining processes such as lithography, Single-point Diamond Turning (SPDT) with a tool servo including Fast Tool Servo (FTS) and Slow Tool Servo (STS) is an enabling and efficient machining process to fabricate microstructures through a simple process to achieve optical surface finish directly, and the microstructured patterns can also be controlled precisely with various shapes.…”