Apparatus for controlling the lapping of a slider based on an amplitude of a readback signal produced from an externally applied magnetic field
US7260887B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 2004 |
| Grant date | Aug 28, 2007 |
| Priority date | — |
| Expiry date | Jun 29, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/53165
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
The lapping of a slider is controlled based on an amplitude of a readback signal which is produced from an externally applied magnetic field. A lapping plate is used to lap a slider which includes at least one magnetic head having a read sensor. During the lapping, a coil produces a magnetic field around the slider and processing circuitry monitors both a readback signal amplitude and a resistance of the read sensor. The lapping of the slider is terminated based on the monitoring both the readback signal amplitude and the resistance. Preferably, the lapping of the slider is terminated when the resistance is within a predetermined resistance range and the readback signal amplitude is above a predetermined minimum amplitude threshold or reaches its peak value. Asymmetry can also be measured in the described system, where the lapping process is terminated based on asymmetry as well as resistance and amplitude measurements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.