Dynamically Controlled Thermal Flying-Height Control Slider

To achieve ultra-low flying height, magnetic spacing variations due to manufacturing tolerances and temperature-induced thermal protrusion need to be reduced. We have developed a thermal flying-height control (TFC) slider that carries a micro-thermal actuator. Previous TFC sliders were mainly statically controlled by a constant power supply. Our purpose is to demonstrate dynamic control of a TFC slider to compensate for high-speed magnetic signal modulation using feed-forward control methods. In this report, to dynamically compensate for magnetic signal modulation using TFC, two methods were examined. In method 1, TFC power was adjusted by using only time domain information. In Method 2, TFC power was adjusted by using frequency domain information in addition to time domain information. Method 2 showed better compensation for magnetic signal modulation due to better compensation at higher frequencies. These results showed that a dynamically controlled TFC slider is feasible in compensating for kilohertz order modulation.