Standardized ESD Testing Of Magnetoresistive Recording Heads

A methodology and apparatus are described for completely characterizing the electrostatic discharge (ESD) sensitivity of magnetoresistive (MR) recording heads. ESD testing of MR heads from six vendors was performed and a "Human Body Model" (HBM) failure voltage as low as 85 V was measured. Air gap breakdown voltages ranging from 400 V to 1100 V were also found. Two new findings were MR sensor damage when ESD pulses were injected into non-MR pins and corona damage. SEM failure analysis after ESD testing showed melting, pitting, and corona damage of the recording head structure. It is concluded that the MR/ESD tester is useful in studying the electrostatic properties of MR recording heads.