Field-induced charged device model testing of magnetoresistive recording heads

Abstract

This paper reports on the behavior of a magnetoresistive (MR) recording head in external electric fields for the first time. Both energy and voltage failure thresholds during field-induced charged device model (CDM) testing are measured. An equivalent circuit model for the MR 0ead is constructed and used in PSPICE circuit simulations. The first atomic force microscope (AFM) data and SEM micrographs of CDM damaged MR heads are also presented and analyzed.

Investigation of ESD Prevention for Deshunted GMR Heads

“…a) E-mail: apirat@kku.ac.th DOI: 10.1093/ietele/e88-c.6.1343 ing head circuit proposed by A. Wallash [4] was adapted to be used in the simulation and circuits of wire with cutting switches are added [3]. In this paper, the charged device model, CDM, is used to investigate the ESD effect in the process.…”

“…Since the HGA is placed in an electrostatic field, the charges in conductors of HGA are induced. So, when the wires are connected or grounded the charges will move and it causes the ESD event [4]. Therefore, the model of FCDM is used in this experiment.…”

ESD testing of head stack assemblies used in magnetic recording hard disk drives

“…It is well known that GMR heads are susceptible to ESD damage by field induced charged device model (CDM) testing at the HGA level [6,7]. In order to simulate a charged HSA being grounded, a homemade field induced model (FIM) test was developed and is shown schematically in Fig.…”

The real CDM field induced ESD waveform from MR heads

“…It has been reported [ 1,2,3,4] that magnetoresistive (MR) heads (sensors) are as sensitive to the CDM (Charged Device Model) event as they are to the HBM (Human Body Model) event [5,6,7,8,9]. In the HBM event, current discharges into the MR Head, whereas the CDM event is a discharge from the MR Head after the latter has been charged up by field induction or direct tribocharging.…”

“…Previously reported CDM ESD waveforms from Magnetoresistive Recording Heads (MR Heads) [ 1,2,3,4] show a double peak (figure 1) at the first peak position, Ipl, and grossly distorted second and third peaks (Ip2 and Ip3 respectively). These reported waveforms are based on a setup where the Head Gimbal Assembly [HGA], that is, both paddle-board and suspension with MR Head, are located on the bare metallic charge plate (figure 2).…”