We Could Tell You, But Then...
ESCA analyzes the top few hundred angstroms of a surface, so Western Digital uses it to examine the various sputtered layers within media. Specifically, WD uses ESCA to quantify surface lubricant and protective carbon layers under 2nm thick on disk media. This is critical to understanding the tribological performance of the head/media interface inside a drive.
Technicians scribe little circles into disk media shards and load these into the ESCA tool to be analysis targets. These two pictures show the stage on which the shards sit, one view from the top and the other through a little peephole on the side.
“One thing we do is measure carbon thickness, and the exact thickness is specified by the given product,” noted our guide. “We have a thickness range of so many angstroms for each of the products. If it extends beyond a few angstroms out of range, they have to redo the process. The exact range is secret.”