Umbrella shield writer (UmSW) design for perpendicular magnetic recording (PMR)

• US 8,879,208 B1
• Filed: 12/02/2013
• Issued: 11/04/2014
• Est. Priority Date: 12/02/2013
• Status: Active Grant

• Current Assignee: Headway Technologies Incorporated (TDK Corporation)
• Original Assignee: Headway Technologies Incorporated (TDK Corporation)
• Inventors: Liu, Yue, Wei, Yaguang, Tang, Yuhui, Dovek, Moris
• Primary Examiner(s): Cao, Allen T
• Application Number:
  US14/093,969
• Time in Patent Office: 337 Days
• Field of Search: 360/125.3, 360/125.03, 360/125.09, 360/125.04, 360/125.17, 360/125.12, 360/125.16, 360/125.06, 360/125.15, 360/125.26, 360/125.31, 360/123.1, 360/123.11
• US Class Current: 360/125.3
• CPC Class Codes: G11B 5/11 Shielding of head against electric or magnetic fields
• CPC Class Codes: G11B 5/1278 specially adapted for magnetisations perpendicular to the surface of the record carrier
• 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
• CPC Class Codes: G11B 5/3146 magnetic layers

Abstract

An umbrella shield (UmS) is included as the uppermost magnetic layer in a trailing shield design in a read/write head to reduce stray field effects, lower bit error rate, and improve protrusion profile for better touch down detection. The UmS may be exposed or recessed from an air bearing surface (ABS), and has a cross-track width, down-track thickness, and length toward a back side that is greater than the corresponding width, thickness, and length dimensions of an underlying PP3 trailing shield. UmS may substantially conform to an arched PP3 shield shape or may be a flat layer. An insulation layer with a thickness of at least 0.3 microns is formed between the UmS and PP3 trailing shield to prevent undesirable coupling. The UmS preferably has a width greater than any other shield in the read/write head.

Claims

1. A trailing shield structure in a combined read head/write head;

comprising;

(a) a first trailing shield layer formed along an air bearing surface (ABS) and having a bottom surface that is separated from a write pole portion of a main pole layer by a write gap;

(b) a second trailing shield layer (PP3) with a front side at the ABS, and a first width between two sides that are formed orthogonal to the ABS, PP3 has a first thickness in a down-track direction and contacts a top surface of the first trailing shield layer along the ABS, and extends with an arch shape to a back side that is a first length from the ABS, PP3 contacts a yoke portion of the main pole layer at a yoke length from the ABS; and

(c) an umbrella shield (UmS) that is a magnetic layer formed above PP3 and substantially conforms to a shape of PP3 wherein UmS has a second width in a cross-track direction between two sides that are formed orthogonal to the ABS, the second width is greater than the first width, a second thickness in a down-track direction that is greater than the first thickness, and UmS extends for a second length from a front side to a back side such that the second length is greater than the first length.

2. The trailing shield structure of claim 1 wherein the front side of the UmS adjoins the ABS in an exposed umbrella shield design.

3. The trailing shield structure of claim 1 wherein the front side of the umbrella shield is recessed from the ABS by a distance of about 0.2 to 1.5 microns.

4. The trailing shield structure of claim 1 wherein the second thickness is about 1.1 to 3 times larger than the first thickness, and each of the second width and second length is about 1 to 5 microns greater than the first width and first length, respectively.

5. The trailing shield structure of claim 1 wherein an insulation layer with a thickness of at least 0.3 microns separates PP3 and the umbrella shield.

6. The trailing shield structure of claim 1 wherein the second width is greater than any other shield width in either of the read head and write head.

7. The trailing shield structure of claim 1 wherein the umbrella shield is made of NiFe, CoFe, or CoFeNi.

8. The trailing shield structure of claim 3 further comprised of two tapered sides on the UmS layer, each tapered side connects an end of the UmS front side to an end of a UmS orthogonal side to form a corner that is recessed a third distance from the ABS wherein the third distance is greater than the recessed distance.

9. The trailing shield structure of claim 1 wherein the front side of UmS is comprised of two tapered sides wherein the tapered sides converge at a point that is recessed from the ABS by a distance of 0.2 to 1.5 microns, and each tapered side forms an angle with respect to the ABS and terminates at an end of one of the UmS orthogonal sides.

10. The trailing shield structure of claim 9 wherein the angle is between about 0.1 and 20 degrees.

11. A trailing shield structure in a combined read head/write head;

comprising;

(a) a first trailing shield layer formed along an air bearing surface (ABS) and having a bottom surface that is separated from a write pole portion of a main pole layer by a write gap;

(b) a second trailing shield layer (PP3) with a front side at the ABS, and a first width between two sides that are formed orthogonal to the ABS, PP3 has a first thickness in a down-track direction and contacts a top surface of the first trailing shield layer along the ABS, and extends with an arch shape to a back side that is a first length from the ABS, PP3 contacts a yoke portion of the main pole layer at a yoke length from the ABS; and

(c) an umbrella shield (UmS) that is a flat magnetic layer formed above PP3 wherein UmS has a second width in a cross-track direction between two sides that are formed orthogonal to the ABS, the second width is greater than the first width, a second thickness in a down-track direction that is greater than the first thickness, and UmS extends for a second length from a front side to a back side in a direction perpendicular to the ABS such that the second length is greater than the first length.

12. The trailing shield structure of claim 11 wherein the front side of the UmS adjoins the ABS in an exposed umbrella shield design.

13. The trailing shield structure of claim 11 wherein the front side of the umbrella shield is recessed from the ABS by a distance of about 0.2 to 1.5 microns.

14. The trailing shield structure of claim 11 wherein the second thickness is about 1.1 to 3 times larger than the first thickness, and each of the second width and second length is about 1 to 5 microns greater than the first width and first length, respectively.

15. The trailing shield structure of claim 11 wherein an insulation layer with a thickness of at least 0.3 microns separates PP3 and the umbrella shield.

16. The trailing shield structure of claim 11 wherein the second width is greater than any other shield width in either of the read head and write head.

17. The trailing shield structure of claim 11 wherein the umbrella shield is made of NiFe, CoFe, or CoFeNi.

18. The trailing shield structure of claim 13 further comprised of two tapered sides on the UmS layer, each tapered side connects an end of the UmS front side to an end of a UmS orthogonal side to form a corner that is recessed a third distance from the ABS wherein the third distance is greater than the recessed distance.

19. The trailing shield structure of claim 11 wherein the front side of UmS is comprised of two tapered sides wherein the tapered sides converge at a point that is recessed from the ABS by a distance of 0.2 to 1.5 microns, and each tapered side forms an angle with respect to the ABS and terminates at an end of one of the UmS orthogonal sides.

20. The trailing shield structure of claim 19 wherein the angle is between about 0.1 and 20 degrees.

21. A method of forming a trailing shield structure in a combined read head/write head;

comprising;

(a) providing a main pole layer having a write pole, and a write gap formed on the write pole;

(b) forming a first trailing shield on the write gap;

(c) forming a second trailing shield layer (PP3) with a front side that contacts a top surface of the first trailing shield and is aligned above a front surface of the write pole, PP3 has a first width in a cross-track direction between two sides that are formed orthogonal to the front side, a first thickness in a down-track direction, and extends with an arch shape to a back side that is a first length from the front side, PP3 contacts a yoke portion of the main pole layer at a yoke length from the write pole'"'"'s front surface;

(d) depositing a first insulation layer on the second trailing shield layer; and

(e) forming an umbrella shield (UmS) that is a magnetic layer formed on the first insulation layer and aligned above PP3, UmS substantially conforms to a shape of PP3 wherein UmS has a front side and a second width in a cross-track direction between two sides that are formed orthogonal to the UmS front side, the second width is greater than the first width, a second thickness in a down-track direction that is greater than the first thickness, and UmS extends for a second length from a front side to a back side such that the second length is greater than the first length.

22. The method of claim 21 further comprised of lapping the combined read head/write head including the trailing shield structure to form an air bearing surface (ABS) proximate to the front surface of the write pole and proximate to the front sides of the second trailing shield and UmS shield.

23. The method of claim 22 wherein the PP3 front side and the front side of the UmS adjoin the ABS in an exposed umbrella shield design.

24. The method of claim 22 wherein the front side of the umbrella shield is recessed from the ABS by a distance of about 0.2 to 1.5 microns.

25. The method of claim 22 wherein the second thickness is about 1.1 to 3 times larger than the first thickness, and each of the second width and second length is about 1 to 5 microns greater than the first width and first length, respectively.

26. The method of claim 21 wherein the insulation layer has a thickness of at least 0.3 microns.

27. The method of claim 21 wherein the second width is greater than any other shield width in either of the read head and write head.

28. The method of claim 22 wherein the front side of UmS is comprised of two tapered sides wherein the tapered sides converge at a point that is recessed from the ABS by a distance of 0.2 to 1.5 microns, and each tapered side forms an angle with respect to the ABS and terminates at an end of one of the UmS orthogonal sides.

29. The method of claim 28 wherein the angle is between about 0.1 and 20 degrees.