Tranducer with improved inductive coupling

• US 5,195,005 A
• Filed: 05/26/1992
• Issued: 03/16/1993
• Est. Priority Date: 06/02/1989
• Status: Expired due to Fees

• Current Assignee: Matsushita-Kotobuki Electronics Industries, Ltd.
• Original Assignee: Digital Equipment Corporation (HP Inc.)
• Inventors: Mallary, Michael L., Shukovsky, Harold B.
• Primary Examiner(s): Levy, Stuart S.
• Assistant Examiner(s): EVANS, JEFFERSON A
• Application Number:
  US07/890,372
• Time in Patent Office: 294 Days
• Field of Search: 360/125, 360/126, 360/123, 29/603
• US Class Current: 360/125.44
• CPC Class Codes: G11B 5/127 Structure or manufacture of heads, e.g. inductive
• CPC Class Codes: G11B 5/17 Construction or disposition of windings
• CPC Class Codes: G11B 5/31 using thin films G11B5/1274, G11B5/1278, G11B5/1874, G11B5/1875, G11B5/33, G11B5/49 take precedence; magnetic thin film structures H01F10/00
• CPC Class Codes: G11B 5/3113 for improving the magnetic domain structure or avoiding the formation or displacement of undesirable magnetic domains
• CPC Class Codes: Y10T 29/49043 Depositing magnetic layer or coating

Abstract

A thin film magnetic transducer includes a yoke having a plurality of arms and a plurality of coils, at least one of which is intertwined with the yoke to provide multiple flux interactions therebetween. Each arm includes a plurality of elongated segments that are oriented obliquely to each other and have easy axes of magnetization respectively transverse to the directions of flux conduction through the segments, and the segments (and arms) are joined together to cause flux to pass between them without flowing parallel to the easy axes.

Claims

1. A thin film magnetic transducer comprising

a yoke having a plurality of arms each of which has at least one easy axis of magnetization, and

a plurality of coils, each one of said coils having at least one turn, said yoke and said coils being intertwined to provide multiple flux interactions between said yoke and said at least one turn of at least one of said coils,

each one of said arms having a plurality of elongated segments each of which is disposed generally along a longitudinal axis of the transducer, said segments being oriented obliquely to each other, each one of said segments having an easy axis of magnetization oriented transverse to the direction of flux conduction through said segment and at an oblique angle with respect to said longitudinal axis,

said segments of said arms being joined together to direct said flux through said plurality of coils.

2. The transducer of claim 1 wherein said transducer is formed in a plurality of thin film layers, and said oblique segments lie in separate said layers, said segments being joined together through an intermediate portion extending between said layers.

3. The transducer of claim 2 wherein segments of said arms disposed in different said layers cross each other.

4. The transducer of claim 1 wherein said transducer is formed in a plurality of thin film layers with said oblique segments lying in separate said layers and being connected together through a transition layer, said coil lying at least in part in said transition layer.

5. The transducer of claim 1 wherein the easy axis of each one of said segments is perpendicular to a direction along which said segment generally extends.

6. The transducer of claim 1 comprising a pair of said coils.

7. The transducer of claim 1 wherein each one of said coils is intertwined with said yoke to provide multiple flux interactions therebetween.

8. The transducer of claim 1 wherein adjacent said segments of each of said arms extend in opposite oblique directions with respect to said longitudinal axis, the easy axis of each one of said adjacent segments being oriented perpendicular to the direction in which said segment extends.

9. The transducer of claim 1 wherein said transducer is formed in a plurality of thin film layers with said adjacent segments of each one of said arms being disposed in separate said layers,

the segments that are disposed in a first one of said layers extending in a first direction arranged obliquely to said longitudinal axis and having easy axes of magnetization perpendicular to said first direction, and the segments that are disposed in a second one of said layers extending in a second direction arranged obliquely to said longitudinal axis and to the first direction and having easy axes of magnetization perpendicular to said second direction, and

at least some of said segments in said first layer being connected to at least some of said segments in said second layer through a transition layer, said coils being disposed in said transition layer so that said flux is directed through each of said coils as said flux conducts through said yoke.

10. The transducer of claim 1 wherein said plurality of coils are spaced from each other along said longitudinal axis and are electrically connected together in series.

11. A process of fabricating a thin film magnetic transducer, comprising

forming a yoke that has a plurality of arms each of which has at least one easy axis of magnetization and providing each one of said arms with a plurality of elongated segments,

disposing each of said segments generally along a longitudinal axis of the transducer, orienting said segments obliquely to each other, and orienting the easy axis of magnetization of each one of said segments transverse to the of flux conduction through said segment and at an oblique angle with respect to said longitudinal axis,

forming a plurality of coils each of which has at least one turn,

interconnecting said segments to intertwine said yoke with said coils and provide multiple flux interactions between said yoke and said at least one turn of at least one of said coils, said interconnecting including joining said segments of said arms to allow said segments to direct said flux through said plurality.

12. The process of claim 11 further comprising

forming said transducer in a plurality of thin film layers so that said oblique segments lie in separate said layers, and

joining said segments together through an intermediate portion extending between said layers.

13. The process of claim 12 further comprising arranging a pair of segments of said arms that are disposed in different said layers in criss-crossing relation.

14. The process of claim 12 further comprising forming said transducer in a plurality of thin film layers with said oblique segments lying in separate said layers, and

connecting said segments together through a transition layer, said coils lying at least in part in said transition layer.

15. The process of claim 12 further comprising orienting the easy axis of each one of said segments perpendicular to a direction along which said segment generally extends.

16. The process of claim 11 comprising forming a pair of said coils.

17. The process of claim 11 wherein each one of said coils is intertwined with said yoke to provide multiple flux interactions therebetween.

18. The method of claim 17 further comprising arranging adjacent said segments of each of said arms so that they extend in opposite oblique directions with respect to said longitudinal axis, and orienting the easy axis of each one of said adjacent segments perpendicular to the direction in which said segment extends.

19. The method of claim 17 further comprising forming said transducer in a plurality of thin film layers with said adjacent segments of each one of said arms being disposed in separate said layers,

configuring the segments that are disposed in a first one of said layers so that they extend in a first direction oblique to said longitudinal axis and have easy axes of magnetization perpendicular to said first direction,

configuring the segments that are disposed in a second one of said layers so that they extend in a second direction oblique to said longitudinal axis and to the first direction and have easy axes of magnetization perpendicular to said second direction, and

connecting at least some of said segments in said first layer to at least some of said segments in said second layer through a transition layer, said coils being disposed in said transition layer so that said flux is directed through each of said coils as said flux conducts through said yoke.

20. The method of claim 17 further comprising spacing said plurality of coils from each other along said longitudinal axis and electrically connecting said coils together in series.

21. A thin film magnetic transducer comprising

a yoke having a plurality of arms extending generally along a longitudinal axis of said transducer, each of said arms having at least one easy axis of magnetization, and

a plurality of coils spaced longitudinally along said axis, each of said coils having at least one turn and being intertwined with said yoke to provide multiple flux interactions between said yoke and said at least one turn of at least one of said coils,

each one of said arms having a plurality of elongated segments that are oriented obliquely to each other, each one of said segments having an easy axis of magnetization oriented transverse to the direction of flux conduction through said segment and at an oblique angle with respect to said longitudinal axis,

said segments of said arms being joined together to direct said flux through said plurality of coils.

22. The transducer of claim 21 wherein said plurality of coils are electrically connected together in series.