Helical Patterning onto Fine Pipes and Fabrication of Long Microcoils

Abstract

The helical patterning onto fine copper pipes of 80 -100 mm diameter was investigated for fabricating microcoil springs, and long microcoils of 5 mm length, 85 -100 mm pitch and with a maximum aspect ratio of 60 were obtained when the patterned specimen pipes were wet-etched. The specimen pipes were coated with a positive resist PMER P-AR900 (Tokyo Ohka Kogyo) of 2.5 -4 mm thickness, and exposed to a blue laser light beam of 473 nm wavelength. After the pipes were exposed while being scanned using a linear stage and a rotation stage, the patterned pipes were etched in ferric chloride solution maintained at 40 -45 C, and transformed into microcoils. As new methods, the inclination of the pipes was precisely corrected by adjusting the size and the position of beam spot, and the etching time was divided into several steps to improve the uniformity.

New Laser-Scan Exposure System for Delineating Precise Helical Patterns onto Sub-50-µm Wires

“…In the conventional system, [7][8][9][10][11][12][13][14][15][16] a solid blue laser (Shimadzu Solid State 473, HK5510) with a wavelength of 473 nm was used as an exposure source. The source was fixed.…”

“…As a result, technology to form helical patterns onto wires and pipes with outer diameters of as small as 80 m was established. [10][11][12][13] In addition, the two microcoil fabrication methods mentioned above were moved to practical application. [14][15][16][17][18][19] Such MEMS microcoils are applied to coil springs used for providing appropriate contact forces in fine electrode probe pins of semiconductor device testers with large-scale integration (LSI).…”

Lithography onto Surfaces of Fine-Diameter Pipes Using Rotary Scan-Projection Exposure

“…To answer the requirement, various researches on developing lithography systems for replicating or delineating patterns on cylindrical materials were carried out [1][2][3][4][5][6][7]. The authors also developed laser-scan exposure systems onto fine wires and pipes with diameters of 40-500 µm [8][9][10][11][12][13]. It was demonstrated that very precise patterns were arbitrarily delineated on surfaces of such very fine cylindrical materials.…”

“…It was demonstrated that very precise patterns were arbitrarily delineated on surfaces of such very fine cylindrical materials. In addition, fabrication processes of fine cylindrical micro-components such as coil springs and pipes with multi-holes were also developed [8][9][10][11] [13].…”

Fabrication of Stainless‐Steel Microcoils and Mesh Pipes Using Lithography

“…In this context, we developed a laser‐scan lithography system to form patterns on the surface of cylindrical and tubular pieces , and made possible fabrication of microcoils by etching helical patterns on copper cylinders . With microcoils fabricated by etching cylindrical pieces, thickness variation can be kept very small.…”