Drag Test as a Diagnostic Tool for Head Disk Interface Durability
Details
Head disk reliability consists of at least of the following : durability, friction/stiction, and chemical integrity. Component and/or drive based css testing has been often used as the sole evaluation tool for all the reliability concerns. We have resurrected the use of the drag test as a quick and simple evaluation tool for head disk durability. This approach seems appropriate in light of the fact that protective coating and lubricant film thick nesses are both decreasing in order to accommodate for the increase in areal density. In an attempt to keep the HDI closely resembling the product HDI the same slider and disk pairs are used at below take-off velocities. We will discuss our findings relative to the conventional css tests, as well as other un-anticipated findings. Our findings will show that drag testing can have predictive as well as diagnostic capabilities.
