Magnetic recording head with magnetic wall angle
View Patent ↗A pole tip shield for a write element of a recording head is disclosed. The pole tip shield is spaced from the pole tip in the leading edge direction to provide a magnetic wall angle to reduce ATI or adjacent track erasure to compensate for the skew angle of the head. In illustrated embodiments, the pole tip shield includes side portions. In illustrated embodiments the pole tip shield is generally “U” shaped and side portions of the pole tip shield include different thickness or width dimensions. In illustrated embodiments, the pole tip shield provides a magnetic wall angle for a rectangular shaped pole tip. Embodiments disclosed in the application include a trailing edge shield separated from the pole tip shield along an air bearing surface of the head by a non-magnetic gap portion.
1. A magnetic assembly comprising:
a magnetic pole having a pole tip and the pole tip including a leading edge, a trailing edge and side edges; and
a generally “U” shaped pole tip shield including a leading edge portion and side portions and the “U” shaped pole tip shield including a variable magnetic moment along a length of the side portions of the generally “U” shaped pole tip shield wherein the variable magnetic moment decreases in a direction towards the trailing edge of the pole tip.
2. The assembly of claim 1 wherein the side portions extend along a length of the pole tip from the leading edge of the pole tip to the trailing edge of the pole tip.
3. The assembly of claim 1 wherein the generally “U” shaped pole tip shield includes a plurality of discrete segments along the side portions and the discrete segments include at least one of different thickness dimensions, different width dimensions or different magnetic materials to provide the variable magnetic moment along the length of the side portions of the “U’ shaped pole tip shield.
4. The assembly of claim 3 wherein the plurality of discrete segments include a plurality of thickness segments comprising a first thickness segment having a first thickness dimension and a second thickness segment including a second thickness dimension smaller than the first thickness dimension in the direction towards the trailing edge of the pole tip.
5. The assembly of claim 1 wherein the side portions of the “U” shaped pole tip shield include a variable thickness or width dimension along the side portions of the “U” shaped pole tip shield.
6. The assembly of claim 1 wherein the “U” shaped pole tip shield includes a plurality of discrete segments along the side portions of the “U” shaped pole tip shield having different width or thickness dimensions and the plurality of discrete segments include different magnetic materials or compositions.
7. The assembly of claim 1 further comprising at least one auxiliary pole and the “U” shaped pole tip shield is magnetically connected to the at least one auxiliary pole.
8. The assembly of claim 1 wherein the side portions of the “U” shaped pole tip shield include different magnetic material segments along the side portions of the “U” shaped pole tip shield to form the variable magnetic moment.
9. The assembly of claim 1 wherein the side portions of the “U” shaped pole tip shield have a shortened length dimension relative to a length dimension of the pole tip between the leading edge and the trailing edge of the pole tip.
10. The assembly of claim 1 wherein the side portions of the “U” shaped pole tip shield include a variable thickness along the side portions of the “U” shaped pole tip shield.
11. The assembly of claim 1 and comprising a first auxiliary pole magnetically connected to the “U” shaped pole tip shield and a second auxiliary pole connected to a trailing edge shield spaced from the “U” shaped pole tip shield and separated from the “U” shaped pole tip shield along an air bearing surface by a non-magnetic gap.
12. The magnetic assembly of claim 1 and comprising:
a trailing edge shield spaced from the “U” shaped pole tip shield; and
a non-magnetic gap portion separating the “U” shaped pole tip shield from the trailing edge shield along an air bearing surface of the assembly.
13. The assembly of claim 12 further comprising an auxiliary pole magnetically connected to the trailing edge shield.
14. The magnetic assembly of claim 1 comprising a coil energizable to induce a magnetic flux in the pole tip.
15. The magnetic assembly of claim 1 wherein the side portions are formed of a variable magnetic moment material to provide the variable magnetic moment that decreases in the direction of the trailing edge of the pole tip.
16. The magnetic assembly of claim 15 wherein the variable magnetic material is formed of a ferromagnetic material having different alloy compositions along the side portions of the “U” shaped pole tip shield.
17. The magnetic assembly of claim 15 wherein the variable magnetic material is formed using different percentage amounts of alloy materials along the length of the side portions of the “U” shaped pole tip shield.
18. The magnetic assembly of claim 1 and comprising a magnetically insulated region between the pole tip and the “U” shaped pole tip shield.
19. The magnetic assembly of claim 1 wherein the side portions of the “U” shaped pole tip shield include a variable width dimension along the side portions of the “U” shaped pole tip shield.
20. The magnetic assembly of claim 8 wherein the different magnetic material segments are formed of different ferromagnetic alloy compositions.