Head with a transducer overcoat having a trailing air flow dam that is shallowly recessed from an air bearing surface
View Patent ↗A head includes a transducer and a slider having an air bearing surface (ABS) and a trailing face. The slider has an overcoat layer that includes the trailing face and that overcoats the transducer. The ABS includes a trailing pad having a major surface adjacent the transducer, with the major surface lying in a primary plane. The ABS also includes a sub-ambient pressure cavity disposed upstream of the overcoat layer and being recessed from the primary plane by a cavity depth in the range 0.8 to 2 microns. The overcoat layer includes a trailing air flow dam being recessed from the primary plane by a step depth in the range 0.05 to 0.5 microns. The overcoat layer also includes a corner region recessed from the primary plane by at least the cavity depth.
1. A head comprising:
a slider having a leading face and a trailing face and an air bearing surface, the air bearing surface defining an upstream direction pointing from the trailing face to the leading face; and
a transducer;
the slider also having an overcoat layer, the overcoat layer including the trailing face and overcoating the transducer;
wherein the air bearing surface includes:
a trailing pad including a major surface adjacent the transducer, the major surface lying in a primary plane;
a sub-ambient pressure cavity disposed upstream of the overcoat layer and being recessed from the primary plane by a cavity depth in the range 0.8 to 2 microns; and
wherein the overcoat layer includes:
a trailing air flow dam being recessed from the primary plane by a step depth in the range 0.05 to 0.5 microns, and
a corner region recessed from the primary plane by at least the cavity depth.
2. The head of claim 1 wherein the slider comprises a wafer substrate material.
3. The head of claim 2 wherein the wafer substrate material is selected from the group consisting of AlTiC and Si.
4. The head of claim 1 wherein the overcoat layer comprises a deposited insulative material.
5. The head of claim 4 wherein the deposited insulative material is selected from the group consisting of Al 2 O 3 and SiO 2 .
6. The head of claim 1 wherein the trailing pad is shaped like a letter W that is oriented so that the center peak of the W points in the upstream direction.
7. The head of claim 1 further including a step surface immediately upstream of the trailing pad, the step surface being recessed from the primary plane by no more than the step depth.
8. The head of claim 1 wherein the air bearing surface further defines a lateral axis that is orthogonal to the upstream direction, the slider having a width measured along the lateral axis, and wherein the trailing air flow dam laterally spans at least 75% of the width of the slider.
9. The head of claim 8 wherein the trailing air flow dam comprises a left portion extending from the transducer along the lateral axis in a first direction, and a right portion extending from the transducer along the lateral axis opposite the first direction, the left and right portions together laterally spanning at least 75% of the width of the slider.
10. The head of claim 1 wherein the air bearing surface further comprises a deep cavity, the deep cavity being recessed from the primary plane by 3 to 4 microns.
11. The head of claim 1 wherein the transducer is a merged magnetic transducer that includes a read element and a writer.