Magnetic head for perpendicular recording having stepped wrap around shield with independent control of write pole track width and flare point dimensions
View Patent ↗Methods and structures for the fabrication of a thin film, perpendicular recording write head are disclosed. The fabrication involves the deposition of two different oxide layers which have mutually high etch selectivities. This characteristic allows a write pole structure to be built wherein the track width is independent of the location of the flare point. The process also produces a structure wherein the throat height of the shield is self aligned to the location of the flare point of the write pole.
1. A thin film perpendicular magnetic head comprising
a write pole having a first flare point and a second flare point,
said write pole having a first portion extending from an air bearing surface to said first flare point, said first portion having a constant first width,
said write pole having a second portion extending from said first flare point to said second flare point, said second portion having a constant second width greater than said first width, and
said write pole having a third portion extending from said second flare point in a direction away from said air bearing surface, said third portion having a width that increases linearly in proportion to a distance from said second flare point.
2. The magnetic head as recited in claim 1 , wherein said first width is approximately equal to a track width of said write pole.
3. The magnetic head as recited in claim 2 , wherein said second width is less than or equal to said track width plus dimension 2D.
4. The magnetic head as recited in claim 1 , further comprising a shield structure having a throat height TH 1 , and a depth above said write pole of dimension W 1 , wherein said depth W 1 is greater than said throat height TH 1 .
5. The magnetic head as recited in claim 4 , wherein said first flare point is located at a dimension FP 1 from said air bearing surface, and said depth W 1 is greater than said dimension FP 1 .
6. The magnetic head as recited in claim 4 , wherein said first flare point is located at a dimension FP 1 from said air bearing surface, said dimension FP 1 being essentially equal to said throat height TH 1 plus the thickness of a first layer and a second layer, said first layer comprising a plating seed layer, said second layer comprising a non-magnetic gap layer.
7. The magnetic head as recited in claim 1 , further comprising a shield structure having
a throat height TH 2 ,
a first portion, immediately above said write pole, having a depth of dimension W 1 2 ,
a second portion, immediately above said first portion, having a depth of dimension W 2 2 ,
wherein, said depth W 1 2 is greater than said throat height TH 2 , and said depth W 2 2 is greater than said depth W 1 2 .
8. The magnetic head as recited in claim 7 , wherein said first flare point is located at a dimension FP 1 from said air bearing surface, and said depth W 1 2 is greater than said dimension FP 1 .
9. The magnetic head as recited in claim 7 , wherein said first flare point is located at a dimension FP 1 from said air bearing surface, and said depth W 2 2 is greater than said dimension FP 1 .
10. The magnetic head as recited in claim 7 , wherein said first flare point is located at a dimension FP 1 from said air bearing surface, said dimension FP 1 being essentially equal to said throat height TH 2 plus the thickness of a first layer and a second layer, said first layer comprising a plating seed layer, said second layer comprising a non-magnetic gap layer.