Timothy Scott Hughbanks

ESD failure mechanisms of inductive and magnetoresistive recording heads

The response of experimental thin-film recording head structures to the excessive current and voltage during an electrostatic discharge (ESD) event is studied. Inductive and magnetoresistive (MR)-like magnetic recording head structures are tested and modeled from the viewpoint of electrostatic theory. An electrical model for the shielded MR-like head structure is proposed and used in circuit simulations to study the response during Human Body Model (HBM) and Machine Model (MM) transients. A testing methodology is defined using HBM and MM ESD transients. A thermal model for thin-film resistor burnout is compared with experiment and predicts a higher failure current than is measured. Results show that the MR structure can fail due to metalization burnout or air breakdown. The HBM metalization burnout failure voltage ranged from 100 V to 300 V, while MM damage started at about 27 V. Air breakdown ranged from 550 V to 650 V.