Differential yoke type read head

(54) DIFFERENTIAL YOKE TYPE READ HEAD

(75) Inventor: Hardayal Singh Gill, Portala Valley, CA (US)

(73) Assignee: Hitachi Global Storage Technologies Netherlands, Amsterdam (NL)

( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 379 days.

(21) Appl. No.: 09/686,191

(22) Filed: Oct. 10, 2000

(51) Int. C I. G11B 5/39

(52) U.S. CI 360/314; 360/317; 360/324.1;

360/324.2

(58) Field of Search 360/314, 317,

360/324.1, 324.11, 324.12, 324.2

(56) References Cited

U.S. PATENT DOCUMENTS

5,757,056 A 5/1998 Chui 257/421

5,862,022 A 1/1999 Noguchi et al 360/324.2

5,898,548 A 4/1999 Dill et al 360/324.2

5,901,018 A 5/1999 Fontana, Jr. et al 360/324.2

6,256,863 Bl * 7/2001 Saito et al 29/603.08

6,278,589 Bl * 8/2001 Gill 360/314

6,344,954 Bl * 2/2002 Redon et al 360/324.2

6,473,275 Bl * 10/2002 Gill 360/314

6,486,662 Bl * 11/2002 Ruigrok et al 324/252

* cited by examiner

A read head, which has an air bearing surface (ABS), includes a yoke which has first and second legs which are interconnected at a location within the head at a distance dt from the ABS wherein the first and second legs have first and second end edges respectively which are located at the ABS and spaced apart by a distance d2. The first and second legs have first and second separations respectively which are located between the ABS and the distance d1 and which magnetically and electrically disconnect leg portions of each leg. The first sensor is magnetically and electrically connected to the first leg across a first separation and a second sensor is magnetically and electrically connected to the second leg across the second separation. The first sensor has a first pinned layer structure and the second sensor has a second pinned layer structure wherein the first and second pinned layer structures have first and second magnetic moments respectively that are antiparallel with respect to each other. With this arrangement the magnetic moments of the read head are out-of-phase with respect to each other so that changes in resistances of the sensors due to field signals, which have a spacing d3 equal to the spacing d2, cause resistances of the sensors to combine to increase the signal of the head and reduce noise by common mode rejection and the remote location of the sensors from the ABS reduces the risk of shorting of the layers of the head when the head is lapped to the ABS.

41 Claims, 8 Drawing Sheets