Differential head integrated touchdown sensors for hard disk drives
AssigneeWestern Digital (Fremont), LLC
InventorsSateeshchandra S. Bajikar, David E. Fowler
Life of this patent
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Abstract
A method and system for providing a disk drive is described. The disk drive includes media such as one or more disks, a slider, and a head residing on the slider. The head has an air-bearing surface (ABS), a portion of which contacts the media during touchdown. The head further includes a plurality of touchdown sensors. A first touchdown sensor is proximate to the ABS, while a second touchdown sensor is distal from the ABS. The touchdown sensors are capable of detecting a temperature change of 0.1 degree Celsius or, in some embodiments, smaller.
Claims25
A disk drive comprising:
- a slider;
- a head residing on the slider and having an air-bearing surface (ABS), a portion of the ABS contacting a medium during a touchdown, the head further including a plurality of touchdown sensors, a first touchdown sensor proximate to the ABS, a second sensor distal from the ABS, the plurality of touchdown sensors capable of detecting a temperature change of 0.1 degree Celsius.
A disk drive comprising:
- a slider;
- a head residing on the slider and having an air-bearing surface (ABS), a portion of the ABS contacting a medium during a touchdown, the head further including a first touchdown sensor proximate to the ABS and a second sensor distal from the ABS, the first touchdown sensor and the second touchdown sensor including at least one of amorphous Ge, Si, GeSi, and GeSiO, each of the first and second touchdown sensors further including a first metal layer, and a second metal layer, a portion of the at least one amorphous semiconductor residing between a portion of the first metal layer and a portion of the second metal layer, each of the first touchdown sensor and the second touchdown sensor capable of detecting a temperature change of 0.1 degree Celsius and having a lateral dimension of not more than one micron;
- and
- differential circuitry coupled with the first touchdown sensor and the second touchdown sensor configured to determine a difference between the first temperature and the second temperature.
A method for detecting a touchdown between a head having an air-bearing surface (ABS) and a disk in a disk drive, the method comprising:
- determining a first temperature of a first touchdown sensor integrated in the head, the first touchdown sensor being proximate to the ABS and capable of detecting a temperature change of 0.1 degree Celsius;
- determining a second temperature of a second touchdown sensor integrated in the head, the second touchdown sensor being distal from the ABS and capable of detecting the temperature change;
- calculating a difference between the first temperature and the second temperature;
- and
- detecting the touchdown based on the difference.
Dependencies are inferred from the claim text.