Thermal and fluid dynamic study on voice coil temperature rise during faster and frequent seeking in hard disk drives

Abstract

The coil temperature of head actuators is a dominant parameter for seek performance and reliability of disk drives. We formulate its basic relation from power consumption to temperature rise. We clarify the power consumption in temperature changing system, and discuss on "Thermorunaway”. In the actual operating drives, we calculate effective power consumption. To calculate thermal resistance in actual drives, we excute internal flow numerical analysis and thermal conductivity simulation. To reduce thermal resistance, we propose internal flow modification as improving impinging flow against the coil. The change improves thermal resistance by around 30% in simulation. The experimental results agree the calculated results