ESD failure mechanisms of inductive and magnetoresistive recording heads

Abstract

The response of experimental thin-film (TF) recording head structures to excessive current and/or voltage during an electrostatic discharge (ESD) event is studied. Inductive and magnetoresistive-like (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 current flow during a human body model (HBM) and machine model (MM) transients. A testing methodology is defined using standard HBM and MM ESD transients. A thermal model for TF 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 to 300 V, while MM damage stated at 27 V. Air breakdown ranged from 550 to 650 V.