The Effects of Parking Time, Temperature, and Slider Position on Lubricant Migration in Hard Disk Drives

Drive-level lubricant migration tests were carried out to study the effects of parking time, temperature, and slider position on lubricant migration in a hard disk drive. The change in head medium spacing after parking the head was determined from read-back signal measurements using the Wallace equation. Time-of-flight secondary ion mass spectrometry was used to correlate the change in head medium spacing with the amount of lubricant migrating to the air-bearing surface during parking. The change in head medium spacing as a function of parking time, temperature, and slider position is determined.