IP Library › Granted Patent US 7,274,541
Granted Patent B2
US 7,274,541 · App. 11/095,533 · Granted Sep 25, 2007

Magnetic thin film head, the fabrication method, and magnetic disk

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Quick Facts
Patent No.
US 7,274,541
App. No.
11/095,533
Granted
Sep 25, 2007
Kind
B2
Abstract

In formation of an upper shield of a magnetic thin film head by electroplating, a current density of electroplating is regulated stepwise with time. Thus, in the upper shield formation, a film composition and magnetic characteristic with respect to the direction of film thickness can be controlled precisely, making it possible to provide a magnetic thin film head featuring significantly reduced noise-after-write and output fluctuation.

Claims (40)

1. A method of fabricating a magnetic thin film comprising the steps of:

a) forming a write head element;

b) forming a read head element;

wherein a ferromagnetic film formed between said write head element and said read head element, having a soft magnetic characteristic and a magnetic shield function is provided in the vicinity of a sensor film arranged as said read head element,

wherein said ferromagnetic film comprises NiFe material and is formed by an electroplating method,

wherein the Ni composition of an initially formed layer of said ferromagnetic film has a thickness of 1.0 μm is 80.8 to 82.0 wt %, and

wherein the Ni in composition of an upper layer above said initially formed layer of said ferromagnetic film is 81.0 to 81.2 wt %,

c) timewise regulating a current density of the electroplating under control of a personal computer;

wherein a Ni content accuracy is controlled to differ in a thickness direction of said ferromagnetic film to decrease a noise-after-write and an output fluctuation,

d) wherein a plurality of time periods and a plurality of current values are preset for film formation.

2. A method of fabricating a magnetic thin film comprising the steps of:

a) forming a write head element; and

b) forming a read head element;

wherein a ferromagnetic film formed between said write head element and said read head element, having a soft magnetic characteristic and a magnetic shield function is provided in the vicinity of a sensor film arranged as said read head element,

wherein said ferromagnetic film comprises NiFe material and is formed by an electroplating method,

wherein in a first region of said ferromagnetic film which exceeds 1.0 μm in thickness from an initial formed layer, Ni content accuracy is ±0.1 wt %, and

wherein in a second region of said ferromagnetic film which is 1.0 μm or less in thickness from said initial formed layer, Ni content accuracy is ±0.3 wt %, wherein a Ni content accuracy is controlled to differ in a thickness direction of said ferromagnetic film to decrease a noise-after-write and an output fluctuation.

3. The method of fabricating a magnetic thin film according to claim 1 , wherein said initially formed layer has a lower Ni content accuracy than said upper layer.

4. The method of fabricating a magnetic thin film according to claim 3 , wherein said Ni content accuracy of said initially formed layer is ±0.3 wt %, and wherein said Ni content accuracy of said upper layer is ±0.1 wt %.

5. The method of fabricating a magnetic thin film according to claim 3 ,

further including changing a current density used for electroplating when said ferromagnetic film is formed.

6. A method of manufacturing a magnetic head, including a substrate, a lower shield, a sensor, a upper shield, comprising steps of:

forming said upper shield including steps of:

forming a first region comprising NiFe by electroplating, and

forming a second region comprising NiFe above said first region by electroplating,

wherein in forming said first and second regions, Ni content accuracy is controlled so that said second region has a higher Ni content accuracy than said first region to decrease a noise-after-write and an output fluctuation.

7. The method of manufacturing a magnetic head according to claim 6 ,

wherein during said forming of said first region a first current is used for electroplating, and during said forming of said second region a second current is used for electroplating,

wherein said second current is larger than said first current.

8. The method of manufacturing a magnetic head according to claim 6 , wherein said first region has a thickness of 1.0 μm or less,

wherein said Ni content accuracy of said first region is ±0.3 wt %, and

wherein said Ni content accuracy of said second region is ±0.1 wt %.

9. The method of manufacturing a magnetic head according to claim 6 ,

wherein Ni composition of said first region is 80.8 wt % to 82.0 wt %, and

wherein Ni composition of said second region is 81.0 wt % to 81.2 wt %.

10. The method of manufacturing a magnetic head according to claim 6 , wherein said first region has a thickness of 1.0 μm or less,

wherein said Ni content accuracy of said first region is ±0.3 wt %,

wherein said Ni content accuracy of said second region is ±0.1 wt %;

wherein Ni composition of said first region is 80.8 wt % to 82.0 wt %, and

wherein Ni composition of said second region is 81.0 wt % to 81.2 wt %.