Case study: an investigation into the cause of 'error rate drift'

During product development some Hewlett-Packard DDS tape drives experienced a gradual increase in their uncorrected error rate when running a particul ar operating test at low humidity. This was known as 'error rate drift'. A combination of system-level testing, signal processing, and atomic force mi croscopy showed that the degradation was caused by contamination on the sur face of the heads. The 'stain' thickness increased each time tape was reuse d, resulting in progressive attenuation of the readback signal amplitude. U sing time-of-flight secondary ion mass spectroscopy the contaminant was ide ntified as inorganic Fe, Si and Al, transferred from the media. (C) 1999 El sevier Science Ltd. All rights reserved.