A study of head stack assembly sensitivity to ESD

Author

Boone, Wayne ; Himle, Jenny ; Porter, Terry ; Perry, Bert

Author_Institution

Maxtor Corp., Longmont, CO, USA

fYear

1999

fDate

28-30 Sept. 1999

Firstpage

373

Lastpage

379

Abstract

It is well known that both giant magnetoresistive (GMR) and MR head gimbal assemblies (HGAs) are susceptible to damage by electrostatic discharge (ESD) from human body model (HBM) and machine model (MM) transients. What is less well known is the susceptibility of a GMR or MR sensor once the HGA has been wired to the pre-amplifier and becomes part of an HSA (head stack assembly). We measured current transients across a current probe at the head position generated by applying an HBM voltage transient at the actuator body, flex or pins. The measured amplitude transfer function (mA through head vs. HBM voltage) through this particular preamp/head stack assembly was about 1 mA/33 V. The determination of damage thresholds for HSAs is essential to determine the level of ESD controls needed for post-HSA manufacturing processes in the production of hard disk drives.

Keywords

disc drives; electronic equipment manufacture; electronic equipment testing; electrostatic discharge; giant magnetoresistance; magnetic heads; magnetoresistive devices; preamplifiers; reliability; sensitivity; transient analysis; 1 mA; 33 V; ESD; ESD controls; ESD damage; ESD damage susceptibility; GMR head gimbal assemblies; GMR sensor; HBM transients; HBM voltage; HBM voltage transient; HGAs; MM transients; MR head gimbal assemblies; MR sensor; actuator body; amplitude transfer function; current probe; current transients; damage thresholds; electrostatic discharge; giant magnetoresistive head gimbal assemblies; hard disk drives; head stack assembly; head stack assembly sensitivity; human body model transients; machine model transients; post-HSA manufacturing processes; pre-amplifier; preamp/head stack assembly; susceptibility; Assembly; Biological system modeling; Current measurement; Electrostatic discharge; Electrostatic measurements; Giant magnetoresistance; Humans; Magnetic heads; Magnetic sensors; Magnetic susceptibility;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrical Overstress/Electrostatic Discharge Symposium Proceedings, 1999

Conference_Location

Orlando, FL, USA

Print_ISBN

1-58637-007-X

Type

conf

DOI

10.1109/EOSESD.1999.819086

Filename

819086