Fabrication of stator winding of electromagnetic micromotor with 1-mm diameter

摘要

Microactuator is one of the important parts in MEMS, various types of microactuators have been developed, which utilize different driving principles such as electrostatic force, piezoelectric effect, shape memory alloys and electromagnetic force. In this paper, the fabrication process of stator winding of $phi 1mm electromagnetic micromotor is discussed. With high-aspect-ratio photolithography process and mask-plating process, the high- aspect-ratio coils can be fabricated, which greatly reduce the resistance and heat of stator winding. With thick sputtered Al$-2$/O$-3$/ films as isolation layers between coils, heat resistance of stator winding is improved. A stator winding has been fabricated, which is composed of 6 layer coils, 42 turns and 9 pairs, its diameter is 1mm and minimum line space is 1 $mu@m, the maximum operation current of the coils is 180mA and resistor is 12-20 approximately ega. The output torque of the electromagnetic micromotor is 1.5 $mu@Nm. the rotational speed of the motor can be adjusted from several hundred to over ten thousand turns per minute and the rotational direction is reversible.