A new fabrication process of a planar coil using photosensitive polyimide and electroplating

Abstract This paper describes the fabrication process of a planar coil which can carry a current density of 1000 A mm −2 or more. The fabrication process includes platinum nuclei deposition by sputtering, formation of a polyimide mould by photolithography, and copper film deposition by electroless plating and electroplating. An electromagnetic motor is assembled by combining a planar coil fabricated by the present method and a sputtered NdFeB magnet 25 μm in thickness. This motor can be driven at 10 000 rpm with a current of 0.117 A.