Write gap structure for a magnetic recording head

• US 9,318,131 B2
• Filed: 06/28/2013
• Issued: 04/19/2016
• Est. Priority Date: 06/28/2013
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Tian, Wei, Yin, Huaqing, Dong, Yan, Mundenar, Joseph M., Xue, Jianhua
• Primary Examiner(s): Dravininkas, Adam B
• Application Number:
  US13/930,776
• Publication Number:
  US 20150002963A1
• Time in Patent Office: 1,026 Days
• Field of Search: 36011901-11904, 360/125.02, 36012509-12511, 36012513-12516, 36012519-12521, 36012546-12548, 36012551-12553, 36012559-12561, 36012564-12566
• US Class Current: 1/1
• CPC Class Codes: G11B 5/23 Gap features G11B5/1871, G11B5/1875, G11B5/265, G11B5/29, G11B5/488 and subgroups, G11B5/4907 and subgroups, G11B5/4969 and subgroups take precedence
• CPC Class Codes: G11B 5/232 Manufacture of gap
• CPC Class Codes: G11B 5/3116 Shaping of layers, poles or gaps for improving the form of the electrical signal transduced, e.g. for shielding, contour effect, equalizing, side flux fringing, cross talk reduction between heads or between heads and information tracks G11B5/3113, G11B5/245 take precedence

Abstract

The present application relates to a write gap structure for a magnetic recording head. In illustrated embodiments, the write gap structure includes multiple write gap segments along a beveled pole tip surface between a top edge and a bottom edge of the beveled pole tip surface to provide a narrow write gap proximate to the air bearing surface and a larger write gap behind the air bearing surface. In illustrated embodiments, the narrow write gap segment is formed between the beveled pole tip surface and a lower back surface of front shield and the larger write gap is formed between the beveled pole tip surface and an upper back surface of the front shield.

Claims

1. A write assembly comprising:

a write pole having a pole tip including a beveled pole tip surface having a bottom edge formed at an air bearing surface and a top edge spaced from the bottom edge;

a front shield spaced from the pole tip including an upper front surface and a lower front surface connected through a front edge located below the top edge of the beveled pole tip surface, and a vertical front surface extending upward from a top of the upper front surface and substantially parallel to the write pole above the top edge of the beveled pole tip surface; and

a non-magnetic write gap including a proximal write gap segment located proximate to the air bearing surface having a proximal gap width extending between the beveled pole tip surface and the lower front surface of the shield and a distal write gap segment having a distal gap width larger than the proximal gap width extending between the beveled pole tip surface and the upper front surface of the shield, the proximal and distal write gaps measured in a direction normal to the beveled pole tip surface,

wherein the upper front surface and the lower front surface are connected through a front step, and

wherein the front step is downwardly sloped towards the air hearing surface at an angle other than 90 degrees to both the air bearing surface and to a plane perpendicular to the air bearing surface.

2. The write assembly of claim 1 wherein the air bearing surface of the pole tip includes a leading edge and a trailing edge formed at the bottom edge of the beveled pole tip surface and the leading edge has a narrower cross-track width dimension than a cross-track width dimension of the trailing edge at the bottom edge of the beveled pole tip surface.

3. The write assembly of claim 1 in combination with a media having a soft under layer and a return pole to form a flux path between the write pole and the return pole through the soft under layer.

4. The write assembly of claim 1 wherein the lower front surface is conformal to the beveled pole tip surface to form a conformal gap along the proximal write gap segment.

5. The write assembly of claim 4 wherein the upper front surface is non-conformal to the beveled pole tip surface to form a non-conformal gap along the distal write gap segment between the front edge and the upper front surface, and a conformal gap along the distal write gap between the write pole above the top edge and the vertical front surface.

6. The write assembly of claim 1 wherein the lower front surface is conformal with the beveled pole tip surface.

7. The write assembly of claim 6 wherein the upper front surface is non-conformal with the beveled pole tip surface.

8. The write assembly of claim 6 wherein the upper front surface is conformal with the beveled pole tip surface.

9. The write assembly of claim 1 wherein the upper and lower front surfaces of the front shield have different slope angles to define the proximal and distal gap widths.

10. The write assembly of claim 1 wherein the proximal gap width is less than 25 nm and the distal gap width is 25 nm or greater.

11. The write assembly of claim 1 wherein the proximal gap width is 20 nm or less and the distal gap width is more than 20 nm.

12. The write assembly of claim 1 and wherein the front step extends from the front edge to a lower edge of the upper front surface that is located below the front edge.

13. A write assembly comprising

a write pole having a beveled pole tip surface;

a front shield spaced from the beveled pole tip surface; and

a non-magnetic write gap between the beveled pole tip surface and a lower front surface of the front shield having a conformal write gap width less than 25 nm, between the beveled pole tip surface and an upper front surface of the front shield having a non-conformal write gap width greater than 25 nm, and between a substantially vertical pole tip surface and a vertical front surface of the front shield having a conformal write gap width of greater than 25 nm, the non-magnetic write gap measured in a direction normal to the beveled pole tip surface,

wherein the front shield includes a surface step connecting the upper and lower front surfaces, and

wherein the surface step is downwardly sloped towards a bearing surface at an angle other than 90 degrees to both the bearing surface and to a plane perpendicular to the bearing surface.

14. The write assembly of claim 13 wherein the conformal write gap width between the beveled pole tip surface and the lower front surface of the front shield is 20 nm or less.

15. The write assembly of claim 13 wherein the upper front surface and the lower front surface have different slope angles.

16. A write assembly comprising:

a write pole having a pole tip including a beveled pole tip surface having a bottom edge formed at a bearing surface and a top edge spaced from the bottom edge;

a front shield spaced from the pole tip including an upper front surface and a lower front surface connected through a front edge located below the top edge of the beveled pole tip surface, and a vertical front surface extending upward from a top of the upper front surface and substantially parallel to the write pole above the top edge of the beveled pole tip surface; and

a non-magnetic write gap including a proximal write gap segment located proximate to the bearing surface having a proximal gap width extending between the beveled pole tip surface and the lower front surface of the shield and a distal write gap segment having a distal gap width larger than the proximal gap width extending between the beveled pole tip surface and the upper front surface of the shield, the proximal and distal write gaps measured in a direction normal to the beveled pole tip surface,

wherein the proximal write gap segment comprises a bi-layered structure with each layer of the bi-layered structure comprising a segment with opposing surfaces that are sloped at an angle other than 90 degrees to both the bearing surface and to a plane perpendicular to the bearing surface, and

wherein the distal write gap segment comprises a tri-layered structure.

17. The write assembly of claim 16 and wherein each layer of the tri-layered structure comprises a segment with opposing surfaces that are sloped relative to the bearing surface at an angle other than 90 degrees.

18. The write assembly of claim 17 and wherein the sloped opposing surfaces in the segment in each layer of the tri-layered structure are substantially parallel opposing surfaces.

19. The write assembly of claim 16 and wherein the sloped opposing surfaces in the segment in each layer of the bi-layered structure are substantially parallel opposing surfaces.

20. The write assembly of claim 16 and wherein at least one layer of the bi-layered structure is a seed layer.

21. A write assembly comprising:

a write pole having a pole tip including a beveled pole tip surface having a bottom edge formed at a bearing surface and a top edge spaced from the bottom edge;

a front shield spaced from the pole tip including an upper front surface and a lower front surface connected through a front edge located below the top edge of the beveled pole tip surface, and a vertical front surface extending upward from a top of the upper front surface and substantially parallel to the write pole above the top edge of the beveled pole tip surface; and

a non-magnetic write gap including a proximal write gap segment located proximate to the bearing surface having a proximal gap width extending between the beveled pole tip surface and the lower front surface of the shield and a distal write gap segment having a distal gap width larger than the proximal gap width extending between the beveled pole tip surface and the upper front surface of the shield, the proximal and distal write gaps measured in a direction normal to the beveled pole tip surface,

wherein the upper front surface and the lower front surface are connected through a surface step, and

wherein the surface step is neither parallel nor perpendicular to the bearing surface.