THIN-FILM MAGNETIC HEAD IN WHICH PERPENDICULAR MAGNETIC RECORD HEAD OVERLAPS ON REPRODUCING HEAD

• US 20070195453A1
• Filed: 02/20/2007
• Published: 08/23/2007
• Est. Priority Date: 02/20/2006
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Touma, Yusuke, KAMEDA, Hiroshi
• Granted Patent: US 7,821,745 B2
• Time in Patent Office: Days
• US Class Current: 360/119.05
• CPC Class Codes: G11B 5/1278 specially adapted for magnetisations perpendicular to the surface of the record carrier
• CPC Class Codes: G11B 5/3967 Composite structural arrangements of transducers, e.g. inductive write and magnetoresistive read G11B5/3906 takes precedence

Abstract

A thin-film magnetic head is provided. The thin-film magnetic head includes a return-yoke layer formed on an opposed surface such that a maximum length of the return-yoke layer is shorter than a longer length of the length of the upper shield layer and the lower shield layer. The length sets in the range of 0 to 2 μm, and more preferably 2 μm. Accordingly, magnitudes of leakage magnetic fields leaked from each front end surface of return-yoke layer, the upper shield layer, and the lower shield layer toward the record medium are balanced and reduced. An advantage of the invention is to provide a thin-film magnetic head so as to prevent a record data recorded in a record medium from being erased.

Claims

1. A thin-film magnetic head comprising:

a perpendicular magnetic recording head formed on a reproducing head so as to overlap therewith,

wherein the reproducing head has an upper shield layer and a lower shield layer opposed to each other in the thickness direction thereof and a reproducing element formed between the upper shield layer and the lower shield layer,

wherein the reproducing head has a first magnetic layer including a major magnetic pole exposed from the opposed surface by a track width TW, a return-yoke layer opposite to the first magnetic layer with a gap layer interposed therebetween on the opposed surface, and a coil layer that generates a recording magnetic field provided between the first magnetic layer and the return-yoke layer, and

wherein a gap in the thickness direction between the return-yoke layer and the upper shield layer is longer than that between the upper shield layer and the lower shield layer.

2. The thin-film magnetic head according to claim 1, wherein a maximum gap in the length direction from the opposed surface of the return-yoke layer is shorter than a longer maximum gap in the height direction from the opposed surface of the upper shield layer and the lower shield layer from the opposed surface by a predetermined length such that the return-yoke layer is formed toward the opposed surface.

3. The thin-film magnetic head according to claim 1, wherein the predetermined gap is in the range of about 0 to 2 μ

m.

4. The thin-film magnetic head according to claim 1, wherein the predetermined length is 2 μ

m.

5. The thin-film magnetic head according to claim 1, a ratio of the maximum length of the upper shield layer to the lower shield layer is in the range of about 0.9 to 1.1.

6. The thin-film magnetic head according to claim 3, wherein the maximum length of the upper shield layer is equal to that of the lower shield layer.

7. The thin-film magnetic head according to claim 1, wherein a whole back end surface of the return-yoke layer extends toward the opposed surface longer by a predetermined length than a back end surface, which is extended in the height direction, in the upper shield layer and the lower shield layer

8. The thin-film magnetic head according to claim 7, wherein each back end surface of the upper shield layer and the lower shield layer has a similar shape.

9. The thin-film magnetic head according to claim 8, wherein each back end surface has inclined sides and a width of the inclined sides becomes gradually smaller from a back end portion of the side end surface of the track width direction in the height direction.

10. A thin-film magnetic head comprising:

a return-yoke layer formed on an opposed surface such that a maximum length of the return-yoke layer is shorter than a longer length of the length of the upper shield layer and the lower shield layer.

11. The thin-film magnetic head according to claim 10, wherein the length is in the range of about 0 to 2 μ

m.

12. The thin-film magnetic head according to claim 11, wherein the length is in the range of about 2 μ

m.

13. The thin-film magnetic head according to claim 10, wherein magnitudes of leakage magnetic fields leaked from each front end surface of return-yoke layer, the upper shield layer, and the lower shield layer toward the record medium are balanced and reduced.