HDD tracking microactuator and its integration issues

Abstract

Integration issues of a micro-actuator for HDD tracking servo were investigated, and many innovative technologies were developed. In order to electrically connect magnetic head to the external electronics, we devised "integrated flexible wire" structure, which is a micro-fabricated flexible electrical wire. Connection between micro-actuator's bonding pad to the suspension was realized by an "inter-connect module," which is a micro-fabricated miniature flexible printed circuit. Connection between components was done by "solder bumper" process, a precise solder ball placement/laser-reflow technology. The size of a micro-actuator must be small enough so that it has minimum impact on the dynamics and packaging density. We have designed extremely area-efficient micro-actuator, which can produce large force by small device area. The thickness of micro-actuator was also reduced to 160 μm by backside grinding of silicon substrate.