Study on ESD Phenomena of Magnetic Head by 1ns Pulse ESD

Abstract

Magnetic Recording heads, the most electrostatic discharge (ESD/EOS) sensitive device of all electric devices, are used for high density magnetic recording applications. Recently, as the devices become increasingly smaller, there has arisen a concern for damaging GMR (Giant Magneto Resistive) heads by EMI. Also, CDM or nano second pulse ESD is key issue for Magnetic head manufacturing. In order to study the effect of ESD (Electro Static Discharge) with nano pulse width for GMR heads, transfer curves of GMR heads using high field QST (Quasi Static Tester) were investigated. By applying ESD damage to GMR head, the transfer curves change the waveforms. Also, there are many kinds of waveforms of transfer curves for after ESD damaged heads. It was found that the degradation of pinned layer was caused by nano pulse ESD and the phenomena were detected by high field QST.