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.

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: lithography, electroplating, and molding]) process is one of the promising techniques for fabrication of microstructures having high aspect ratios. Microstructures as high as a few hundred µm or more are widely used for various devices, such as micro-actuators, micro-mechanisms, and micro-sensors. The key to reducing the microstructure fabrication cost of the LIGA process is by using micro replication technology. Hot embossing is attracting the attention of engineers as one such technology for economically mass-fabricating microstructures on thin plastic sheets. This technology is especially effective for precisely replicating micro patterns on relatively large sheets. This paper describes the results of research the authors recently carried out to find the optimal conditions for hot embossing in the atmosphere and in a vacuum. For a series of experiments, we prepared two types of Ni molds each containing an area of 33 × 33 mm 2 distributed with hole or column patterns 60 µm in diameter and 1.0 in aspect ratio. The LIGA process using synchrotron radiation fabricated these patterns. From the experiments, we could determine the optimal conditions for replicating these patterns on PMMA sheets in a normal-atmosphere and vacuum environments.

We designed a scheme to introduce the LIGA process, reduce the coil line width while improving the performance, and thereby drastically cut the production costs. Consequently, we succeeded in fabricating prototype microcoils (line width: 10 gtm, aspect ratio: approx. 1). However, improvement in performance of the microcoils requires an increased aspect ratio. We set an objective to fabricate microcoil lines of a high aspect ratio with the dipping method and 3D X-ray lithography in an effort to improve the performance of microcoils.And we succeeded in fabricating microcoil line with a line width of 10 jm and an aspect ratio greater than 5.

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