| US 7,508,626 B2 | ||
| Thin film magnetic head having magnetic pole with controlled dimensions | ||
| Shigeru Ichihara, Tokyo (Japan); Akihiro Oda, Tokyo (Japan); Tetsuya Roppongi, Tokyo (Japan); and Naoto Matono, Saku (Japan) | ||
| Assigned to TDK Corporation, Tokyo (Japan); and SAE Magnetics (H.K.) Ltd., Hong Kong (China) | ||
| Filed on Nov. 25, 2003, as Appl. No. 10/720,478. | ||
| Claims priority of application No. 2002-352797 (JP), filed on Dec. 04, 2002. | ||
| Prior Publication US 2004/0184191 A1, Sep. 23, 2004 | ||
| Int. Cl. G11B 5/187 (2006.01) | ||
| U.S. Cl. 360—125.06 [360/125.12; 360/125.14] | 4 Claims |
| 1. A thin film magnetic head comprising:
a thin film coil for generating a magnetic flux; and
a magnetic pole layer for emitting the magnetic flux generated by the thin film coil toward a recording medium which moves
in a predetermined medium traveling direction and for magnetizing the recording medium in a direction orthogonal to the surface
of the recording medium,
the magnetic pole layer having a magnetic pole end surface exposed in a recording-medium-facing surface which faces the recording
medium and including a track width specifying part specifying a recording track width of the recording medium,
wherein when length in the direction orthogonal to the recording-medium-facing surface in the track width specifying part
of the magnetic pole layer is set as D and width of a magnetic pole edge positioned on a medium outflow side in the medium
traveling direction of the magnetic pole end surface is set as W, a dimensional ratio D/W lies within the range of 0<D/W≤2.3,
wherein the track width specifying part is made of an alloy containing iron (Fe) and cobalt (Co) and having a coercive force
of less than 5.0×103/(4π) A/m,
wherein the width W of the magnetic pole edge is 0.3 μm or less,
wherein the magnetic pole layer further includes a wide part coupled to the track width specifying part and having a width
larger than the width of the track width specifying part, and
when total length of the track width specifying part and the wide part in the magnetic pole layer is set as L1 and the width of the wide part is set as L2, a dimensional ratio L1/L2 lies within the range of 0.25<L1/L2<1.0.
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