Submicron track-width pole-tips for electromagnetic transducers
View Patent ↗A trailing pole-tip for an electromagnetic transducer is formed as a layer oriented substantially perpendicular to other layers of the transducer, allowing the pole-tip to be made much thinner than conventional pole-tips. The novel pole-tip is formed on an edge or sidewall of a base layer instead of being formed on top of an existing layer. Potential errors in pole-tip thickness are much less than standard error tolerances for conventional pole-tip thickness. Having a greatly reduced pole-tip width significantly reduces the track width so that many more tracks can fit on a media surface, providing a large increase in areal density.
1. A transducer comprising:
a plurality of solid layers, including a magnetically soft loop substantially encircling an electrically conductive coil section and terminating in lead and trailing magnetically soft layers separated by an amagnetic gap layer, said trailing magnetically soft layer being oriented substantially perpendicular to said amagnetic layer, wherein said trailing magnetically soft layer has a width measured in a direction substantially parallel to said amagnetic layer, said width being less than about two hundred nanometers and greater than about twenty angstroms;
wherein said trailing magnetically soft layer has a length measured in a direction substantially perpendicular to said amagnetic layer, with said length being at least six times greater than said width.
2. The transducer of claim 1 , wherein a distance between said magnetically soft layers is not substantially greater than said width.
3. The transducer of claim 1 , wherein said trailing magnetically soft layer contains a refractory metal.
4. The transducer of claim 1 , wherein said trailing magnetically soft layer contains material having a B s higher than that of Permalloy.
5. The transducer of claim 1 , wherein said leading magnetically soft layer is substantially perpendicular to said trailing magnetically soft layer.
6. The transducer of claim 1 , wherein said leading magnetically soft layer contains vacuum-deposited material.
7. The transducer of claim 1 , further comprising a magnetoresistive sensor layer disposed adjacent said leading magnetically soft layer and oriented substantially perpendicular to said trailing magnetically soft layer.
8. The transducer of claim 1 , wherein said magnetically soft loop includes a magnetically soft trailing yoke layer that adjoins said trailing magnetically soft layer.
9. The transducer of claim 8 , wherein said trailing yoke layer extends further in said direction substantially parallel to said amagnetic layer than in a direction substantially perpendicular to said amagnetic layer and aligned with said leading and trailing magnetically soft layers.
10. The transducer of claim 1 , wherein said trailing magnetically soft layer is laminated.
11. A transducer for an information storage system, the transducer comprising:
a plurality of solid layers, including a magnetoresistive sensor layer and a magnetically soft loop substantially encircling an electrically conductive coil section and terminating adjacent a media-facing surface in leading and trailing magnetically soft layers separated by an amagnetic gap layer, said trailing magnetically soft layer being oriented substantially perpendicular to said magnetoresistive sensor layer and having a width measured in a direction substantially parallel to said magnetoresistive sensor layer, said width being less than about two hundred nanometers and greater than about twenty angstroms;
wherein said trailing magnetically soft layer has a length measured in a direction substantially perpendicular to said magnetoresistive sensor layer, with said length being at least six times greater than said width.
12. The transducer of claim 11 , wherein said trailing magnetically soft layer is substantially perpendicular to said amagnetic layer.
13. The transducer of claim 11 , wherein said trailing magnetically soft layer is substantially perpendicular to said leading magnetically soft layer.
14. The transducer of claim 11 , wherein said trailing magnetic soft layer is laminated.
15. The transducer of claim 11 , wherein said width of said trailing magnetically soft layer is not substantially greater than a thickness of said amagnetic layer.
16. The transducer of claim 11 , wherein said trailing magnetically soft layer contains material having a B s higher than that of Permalloy.
17. The transducer of claim 11 , wherein said trailing magnetically soft layer contains a refractory metal.
18. The transducer of claim 11 , wherein said trailing magnetically soft layer is sputter-deposited.
19. The transducer of claim 11 , wherein said leading magnetically soft layer is sputter-deposited.
20. The transducer of claim 11 , wherein said magnetically soft loop includes a magnetically soft trailing yoke layer that adjoins said trailing magnetically soft layer.
21. The transducer of claim 20 , wherein said trailing yoke layer extends further in said direction substantially parallel to said magnetoresistive sensor layer than in a direction substantially perpendicular to said magnetoresistive sensor layer and aligned with said leading and trailing magnetically soft layers.
22. A transducer comprising:
a magnetoresistive sensor layer,
a magnetically soft loop disposed adjacent to said magnetoresistive sensor layer, traversed by an electrically conductive coil section and including magnetically soft leading and trailing pole-tips disposed adjacent to a media-facing surface, said trailing pole-tip aligned with said magnetoresistive sensor layer along a longitudinal direction and having a width measured in a track-width direction that is perpendicular to said longitudinal direction, said longitudinal and track-width directions being substantially parallel to said media-facing surface, said width being less than two hundred nanometers and greater than twenty angstroms;
wherein said trailing pole-tip has a length measured in said longitudinal direction, said length being at least five times greater than said width.
23. The transducer of claim 22 , wherein said leading and trailing pole-tips are separated by a submicron nonferromagnetic gap layer.
24. The transducer of claim 22 , wherein said trailing pole-tip consists essentially of sputtered material.
25. The transducer of claim 22 , wherein said trailing pole-tip contains material having a B s higher than that of Permalloy.
26. The transducer of claim 22 , wherein said leading magnetically soft loop includes a magnetically soft yoke layer adjoining said trailing pole-tip.
27. The transducer of claim 26 , wherein said yoke layer extends further in said track-width direction than in said longitudinal direction.
28. The transducer of claim 22 , wherein said trailing pole-tip is laminated.
29. A disk drive comprising:
a rigid magnetic disk, and
a magnetic head disposed adjacent to the disk, the head including a magnetically soft loop substantially encircling an electrically conductive coil section and terminating in leading and trailing magnetically soft layers separated by an amagnetic gap layer, one of said magnetically soft layers being oriented substantially perpendicular to said amagnetic layer, wherein said one magnetically soft layer has a width measured in a direction substantially parallel to said amagnetic layer, said width being less than about two hundred nanometers and greater than about twenty angstroms;
wherein said trailing magnetically soft layer has a length measured in a direction substantially perpendicular to said amagnetic layer, said length being at least six times greater than said width.
30. The disk drive of claim 29 , wherein a distance between said magnetically soft layers is not substantially greater than said width.
31. The disk drive of claim 29 , wherein said trailing magnetically soft layer contains a refractory metal.
32. The disk drive of claim 29 , wherein said trailing magnetically soft layer contains material having a B s higher than that of Permalloy.
33. The disk drive of claim 29 , wherein said leading magnetically soft layer is substantially perpendicular to said trailing magnetically soft layer.
34. The disk drive of claim 29 , wherein said trailing magnetically soft layer contains vacuum-deposited material.
35. The disk drive of claim 29 , further comprising a magnetoresistive sensor layer disposed adjacent said leading magnetically soft layer and oriented substantially perpendicular to said trailing magnetically soft layer.
36. The disk drive of claim 29 , wherein said magnetically soft loop includes a magnetically soft trailing yoke layer that adjoins said trailing magnetically soft layer.
37. The disk drive of claim 29 , wherein said trailing magnetically soft layer is laminated.
38. A disk drive comprising:
a rigid magnetic disk; and
an electromagnetic transducer disposed adjacent to said disk, the transducer including a magnetoresistive sensor layer, and a magnetically soft loop disposed adjacent to said magnetoresistive sensor layer, traversed by an electrically conductive coil section and including magnetically soft leading and trailing pole-tips disposed adjacent to a media-facing surface, said trailing pole-tip aligned with said magnetoresistive sensor layer along a longitudinal direction and having a width measured in a track-width direction that is perpendicular to said longitudinal direction, said longitudinal and track-width directions being substantially parallel to said media-facing surface, with said width being less than two hundred nanometers and greater than twenty angstroms;
wherein said trailing pole-tip has a length measured in said longitudinal direction, said length being at least five times greater than said width.
39. The disk drive of claim 38 , wherein said leading and trailing pole-tips are separated by a submicron nonferromagnetic gap layer.
40. The disk drive of claim 38 , wherein said trailing pole-tip consists essentially of sputtered material.
41. The disk drive of claim 38 , wherein said trailing pole-tip contains material having a B s higher than that of Permalloy.
42. The disk drive of claim 38 , wherein said magnetically soft loop includes a magnetically soft yoke layer adjoining said trailing pole-tip.
43. The disk drive of claim 42 , wherein said yoke layer extends further in said track-width direction than in said longitudinal direction.