Resin micromachining by roller hot embossing

Abstract

The roller hot embossing is an efficient process of manufacture in which patterns are continuously transcribed on film, etc. Recently, the application of the embossing roll to the manufacturing processes of micro parts is paid attention. In this paper, we examined the development of the embossing roll with patterns of micron level and we tried to make the embossing roll mold by using the LIGA process. In this study, instead of producing embossing patterns directly on the roll surface, we fabricated a flexible thin mold with micro-patterns, which was then wrapped onto a cylinder to form an embossing roll, and tested the soft-mold roller hot embossing method. First, by optimizing UV exposure conditions of UV lithography, we prepared a resist pattern of numerous dots with a diameter of 10 lm, a sag height of 8 lm and a pitch of 20 lm. By Ni-electroforming this pattern, a 50 lm-thick thin mold was successfully fabricated. The 50 lm-thick mold was then wrapped onto a cylinder to form an embossing roll. In the roller hot embossing process, the 10 lm-diameter dot shape was successfully replicated on PET sheets.

Rapid polymer microchannel fabrication by hot roller embossing process

“…Recent studies have reported that the imprinted microstructure is correlated to key process parameters such as embossing temperature, roller speed, and roller embossing pressure (Ishizawa et al 2008;Ng and Wang 2009;Yeo et al 2009Yeo et al , 2010. It was found that higher process temperature and process pressure are usually required.…”

“…Therefore, the polydimethylsiloxane (PDMS) soft roller mold (Wu et al 2009) used in UV roller embossing is not suitable. A commonly used roller mold fabrication method involves electroplating the nickel microstructure onto a flexible metal film and wrapping it onto the cylinder roller to form a robust roller mold (Ishizawa et al 2008;Ng and Wang 2009;Yeo et al 2009Yeo et al , 2010. Other methods, such as spin coating liquid crystal polymer (LCP) (Shan et al 2010) or poly(urethane acrylate) (PUA) (Seo et al 2007) onto a flexible sheet, are also effective methods for hot roller embossing.…”

“…Instead of using a UV light source, hot roller embossing uses a hot roller to heat the thermoplastic film above its T g , imprints the microstructure onto the thermoplastic film, and releases the imprinted film from the mold. Several types of thermoplastic materials, including poly(methyl methacrylate) (PMMA) Yeo et al 2010), PET (Ishizawa et al 2008), PVC (Shan et al 2010), polystyrene (PS) (Seo et al 2007), and PC (Velten et al 2008) have been used in the hot roller embossing process.…”

Fabrication of UV range light guide plate

“…In this study, we performed what the most suitable bump shape derived, manufacture by the UV-LIGA process and evaluation by the photocatalyst. In addition, in our laboratory, we perform injection molding and molding by the roller hot embossing (Ishizawa et al 2008), but this study uses the injection molding.…”

A polymer-metal hybrid flexible mould and application for large area hot roller embossing

“…Both roller embossing and roll-to-roll embossing are cost-effective and productive approaches for high volume fabrication once the embossing moulds are generated, and they have been used in fabricating components for micro optical (Chang et al 2006), microfluidic devices (Velten et al 2008) as well as textile fibers (Schift et al 2006). There are three methods for mould configuration: (1) the template patterns are fabricated directly on a roller surface via chemical etching (Jiang et al 2008;Ishizawa et al 2008), plating or precision machining; (2) the patterns are formed on a thin film via etching or plating, the patterned thin film is overlapped atop plastic substrate and fed through the embossing rollers (Shan et al 2009); (3) the patterns are fabricated on a thin and flexible film to form an embossing mould, and the mould is wrapped around an embossing roller (Ahn and Guo 2008). Flexible moulds, which were frequently used in above (2) and (3), were fabricated via photolithograph and nickel plating on thin nickel foils.…”