TUNABLE CONTACT DETECTION SENSITIVITY TO DIRECTLY MEASURE CLEARANCE OF PROTRUSIONS IN MAGNETIC RECORDING HEADS

摘要

Embodiments disclosed herein generally relate to contact at the disk by the recording head in a hard disk drive. In one embodiment, a direct current is applied to an element in a HAMR head. An alternating current is then applied to the element over top of the direct current to cause the HAMR head to dither. By monitoring the head signal at the dither frequency, a touchdown or contact of a NFT on a disk may be detected based upon variations in the produced signal.

主权项

1. A method, comprising;
applying a direct current to a thermal fly height control element of a magnetic recording head; applying an alternating current to the thermal fly height control element to dither the magnetic recording head to produce a magnetic recording head signal; monitoring the dithered magnetic recording head signal; contacting the disk with the magnetic recording head and backing the magnetic recording head off while the dithered magnetic recording head signal is monitored; and detecting a touchdown based upon variations in the dithered magnetic recording head signal.