Current-assisted magnetic recording write head with wide conductive element in the write gap
A current-assisted magnetic recording write head has an electrically conductive layer in the write gap between the write pole and the trailing shield. Electrical circuitry directs current between the write pole and the trailing shield, through the conductive layer in the write gap. The current through the conductive layer generates an Ampere field substantially orthogonal to the magnetization in the write pole to assist magnetization switching of the write pole. The conductive layer is wider in the cross-track direction than the trailing edge of the write pole and may extend beyond the write pole side gaps so as to be in contact with both the side shields and the trailing shield. The conductive layer may have substantially the same along-the-track thickness across its width or it may have a thicker central region at the write pole trailing edge and thinner side regions.
1. A magnetic recording write head for magnetizing data tracks in a magnetic recording disk, the write head comprising:
a write pole formed of ferromagnetic electrically-conductive material and having an end for facing the disk, the write pole end having a leading edge and a trailing edge spaced apart along a line referred to as an along-the-track line, the write pole trailing edge having a width along a line substantially orthogonal to the along-the-track line referred to as a cross-track line;
a trailing shield formed of ferromagnetic electrically-conductive material and having an end for facing the disk, the trailing shield end being spaced along-the-track from the write pole trailing edge to define a write gap;
an electrically-conductive layer in the write gap, the electrically-conductive layer having a cross-track width greater than the cross-track width of the write pole trailing edge; and
wherein the write pole and trailing shield are adapted to pass electrical current between the write pole and trailing shield through the electrically-conductive layer in the write gap.
2. The head of claim 1 wherein the electrically-conductive layer is in contact with the trailing shield.
3. The head of claim 1 wherein the electrically-conductive layer has a central region with a cross-track width at least as wide as the cross-track width of the write pole trailing edge and a side region on each cross-track side of the central region.
4. The head of claim 3 further comprising a layer of electrically insulating material between each electrically-conductive layer side region and the trailing shield.
5. The head of claim 1 further comprising a side shield on each cross-track side of the write pole end and a side gap between each side shield and the write pole end.
6. The head of claim 5 wherein each side gap is formed of electrically-insulating material.
7. The head of claim 5 wherein each side gap is formed of non-magnetic electrically-conducting material.
8. The head of claim 5 wherein the electrically-conductive layer cross-track width is at least as wide as the total cross-track width of the write pole trailing edge and both side gaps.
9. The head of claim 8 wherein the electrically-conductive layer is in contact with both side shields.
10. The head of claim 8 further comprising a layer of electrically insulating material between the electrically-conductive layer and each side shield.
11. The head of claim 1 wherein the electrically-conductive layer comprises a material selected from Cu, Au, Ag, Ru, Cr, W, Ni, Ta, Mo, Pt, Rh and alloys thereof.
12. The head of claim 1 further comprising electrical circuitry connected to the write pole and the trailing shield.
13. A magnetic recording disk drive comprising:
the write head of claim 12 ; and
a rotatable magnetic recording disk having a perpendicular magnetic recording layer with data tracks.
14. A magnetic recording disk drive write head for magnetizing regions in data tracks of a magnetic recording layer on a disk, the write head being formed on a slider having a gas-bearing surface (GBS), the write head comprising:
a write pole formed of ferromagnetic electrically-conductive material and having an end substantially at the GBS, the write pole end having a leading edge and a trailing edge spaced apart along a line referred to as an along-the-track line, the write pole trailing edge having a width along a line substantially orthogonal to the along-the-track line referred to as a cross-track line;
a side shield on each cross-track side of the write pole end and a side gap between each side shield and the write pole end;
a trailing shield formed of ferromagnetic electrically-conductive material and having an end substantially at the GBS, the trailing shield end being spaced along-the-track from the write pole trailing edge to define a write gap;
a non-magnetic electrically-conductive layer in the write gap in contact with the write pole trailing edge and the trailing shield, the non-magnetic electrically-conductive layer having a cross-track width greater than the cross-track width of the write pole trailing edge;
an electrical circuit coupled to the write pole and the trailing shield for directing electrical current between the write pole and trailing shield through the non-magnetic electrically-conductive layer in the write gap;
a return pole formed of ferromagnetic electrically-conductive material and coupled to the trailing shield; and
an electrical coil coupled to the write pole and return pole for generating a magnetic write field in the write pole.
15. The head of claim 14 wherein the non-magnetic electrically-conductive layer is in contact with both side shields.
16. The head of claim 15 further comprising a layer of electrically insulating material between the non-magnetic electrically-conductive layer and each side shield.
17. The head of claim 14 wherein the non-magnetic electrically-conductive layer has a central region with a cross-track width at least as wide as the cross-track width of the write pole trailing edge and a side region on each cross-track side of the central region.
18. The head of claim 17 further comprising a layer of electrically insulating material between each non-magnetic electrically-conductive layer side region and the trailing shield.
19. The head of claim 14 wherein both side gaps are formed of a non-magnetic electrically-insulating material or a non-magnetic electrically-conducting material.
20. A magnetic recording disk drive comprising:
the write head of claim 14 ; and
a rotatable magnetic recording disk having a perpendicular magnetic recording layer with data tracks.