Tribology applications of surface reflectance analyzers: optical characterization of the head disk interface

In this paper, we will discuss Surface Reflectance Analyzers (SRA) and their applications in tribology. We will show how the SRA instrument can be used to locate and quantify tribological parameters, such as carbon wear and lubricant buildup, at the head/disk interface. This damage can be caused by a variety of head/disk interactions. In one case, we will demonstrate the importance of slider crown on tribological performance by quantitatively comparing the damage to the disk surface during continuous start–stop test in the laser texture zone. In another case we will demonstrate the importance of slider air bearing design in ramp load/unload tests by quantitatively comparing the amount of damage near the OD of the disk. Ramp load/unload damage manifests itself in various forms. In addition to local carbon wear and lubricant effects, there is also debris from the ramp wear and occasional “dings”. We will show how the SRA system can be used to distinguish and quantify these various types of damage.