Acceleration test method for GMR/TMR head instability

Abstract

  A method of testing acceleration to assess instability in GMR and TMR heads was developed. Head instability appears as the output of change in signal amplitude and/or signal distortion with spike noise in both heads. A new tool for testing instability in hard disk drives (HDDs) with various acceleration-condition functions was developed to characterize the relation between instability and acceleration conditions. Classification of head instability in HDDs is proposed with the use of this new tool.