Direct fabrication of rigid microstructures on a metallic roller using a dry film resist

Abstract

This paper presents a novel method to fabricate a metallic roller mold with microstructures on its surface using a dry film resist (DFR). The DFR is laminated uniformly onto the curvy surface of a copper roller. After that, the micro-scale photoresist on the surface of the roller can be patterned by non-planar lithography using a flexible film photomask, followed by ferric chloride wet etching to obtain the desired microstructures. This method overcomes the uniformity issue of photoresist coating on rollers, and solves the molds sliding problem during the embossing process because the microstructures are fabricated directly on the roller surface. Furthermore, the rigid metallic roller mold has excellent strength durability and temperature endurance, which can be used in roller hot embossing with a high embossing pressure. The fabricated microstructure roller mold is used as a mold in the hybrid extrusion roller embossing process and successfully fabricates uniform micro-scale prominent line arrays on PC films. This result proves that the roller fabricated by this method can be successfully used in roller embossing for microstructure mass production. The excellent flatness of dry film resist laminating is the key in this fabrication process. The flexible film photomask can be easily designed using CAD software; this roller fabrication method enhances the design flexibility and reduces the cost and time.

From Cleanroom to Desktop: Emerging Micro-Nanofabrication Technology for Biomedical Applications

“…Moreover, emerging environmentally responsive materials can find their applications in biosensing and bio-manipulation platforms 127Table 1Materials used in the desktop micro-nanofabricationMaterial categoriesRepresentative materialsTypical micro-nanofabrication methodsBiocompatibility and toxicityBiomedical applicationsThermoset polymersPDMS6,49,53,62,116,126,156,177,201,204,216,217MoldingBiocompatibleUsed in almost all microfluidic and bio-/nanopatterning applicationsThermoplastic polymersPMMA102,115Hot embossingBiocompatibleConstruct for microfluidicsCOC172Hot embossingBiocompatibleUsed in optofluidic applications primarilyPolystyrene/polyolefin28,59,137,171Heat-activated shrinkageBiocompatibleDevice packaging; pattern transfer; cell culture platformPhotopatternable polymersSU81,18,23,45,113KMPR170LithographyToxicMaster for microfluidics and bio/nanopatterningDry film79,105,173,183,184,192,193,214LithographyBiocompatibleMaster for microfluidics and bio/nanopatterningPEG38,100,104,159,160…”

Rounding of Negative Dry Film Resist by Diffusive Backside Exposure Creating Rounded Channels for Pneumatic Membrane Valves

“…DFR technology is competitive to standard SU-8 processes in respect to feature size [12,13] and consistent height of the resist over a large substrate area [14,15]. Nevertheless, fabrication of round shaped channels in DFR technology for the realization of microfluidic membrane valves and pumps is not feasible yet, other than for SU-8 technology [16].…”

Fabrication of seamless roller molds using step-and-rotate curved surface photolithography and application on micro-lens array optic film

“…Direct machining on the surface of a metal roller using diamond cutters and precision turning machines is commonly utilized in industries but is limited to simple and 2D structures with larger feature sizes only. To achieve roller molds with smaller feature sizes and more complex patterns, typical methods are thin mold wrapping [2][3], soft mold casting [4], modified LIGA [5], direct laser machining, and curved surface photolithography [6].…”