Novel Fabrication Method of Microcoil Springs Using Laser-Scan Helical Patterning and Nickel Electroplating

作者：Horiuchi Toshiyuki^*; Ishii Hidetoshi; Shinozaki Yasuhide; Ogawa Tetsuya; Kojima Kesao

来源：Japanese Journal of Applied Physics, 2011, 50(6): 06GM10.

DOI：10.1143/JJAP.50.06GM10

A novel microcoil fabrication method was developed. In the past research, copper microcoils were fabricated by wet-etching copper pipes with helical resist patterns formed using laser-scan lithography. However, etched coil widths often locally fluctuated owing to the influence of the surface and backsurface conditions of the pipes, and it was difficult to consistently fabricate microcoils with homogeneous widths. For this reason, in the new method, microcoils are fabricated by nickel electroplating instead of etching. After forming helical patterns on a fine stainless-steel wire with a diameter of 80 mu m, nickel was electroplated in the spaces of resist patterns. Because the adhesion of nickel to the stainless-steel wire was not very strong, helically electroplated nickel was tore off from the core wire, and the microcoil was fabricated when the wire was pulled and lengthened. Next, helical pattern widths and nickel coil widths were evaluated. The homogeneity and reproducibility of both widths were very good, and width variations of nickel microcoils were almost the same level as those of resist space patterns. This finding was considered to indicate that the width fluctuation occurring during the electroplating process was very small. The fabricated nickel coils showed almost linear spring characteristics when they were repeatedly compressed and released. The spring constant of the fabricated coil was approximately 0.16 N/mm. The new method and the fabricated nickel coils will be of practical use.

• 出版日期2011-6