Precision etch dimension measurement of hard disk heads
In order to reliably produce hard disk heads with proper performance, a disk head manufacturer must be able to measure the etch dimensions accurately. The required precision can be on the order of a few tenths of a micron or less, requiring nanometer-level detection of the pole tip and the locations of the various edges of the etched steps.
Since the dimensions of the part are so small, and maintaining the surface quality of the head is important, measurements must be performed by an extremely precise non-contact optical coordinate measuring microscope.