ESD Tolerance of GMR and TMR Heads Within Hard Disk Drives

Electrostatic discharge (ESD) tolerance is discussed for giant magnetoresistive (GMR) and tunneling magnetoresistive (TMR) heads within hard disk drives (HDDs). There are two kinds of testing methods for ESD: the component ESD method with Human Body Model or Machine Model and the IEC61000-4-2 testing method. The IEC61000-4-2 testing method for GMR and TMR heads within head gimbal assembly (HGA), head stack assembly (HSA), and HDD was surveyed first, and the ESD tolerance at each state of HGA, HSA, and HDD was evaluated. The equivalent circuits for three states were proposed and proved to be consistent with experimental results by the IEC61000-4-2 testing method.