Thin-film magnetic transducer with multiple yoke-coil interactions and elongated lateral yoke vias

• US 5,418,668 A
• Filed: 10/05/1993
• Issued: 05/23/1995
• Est. Priority Date: 02/14/1992
• Status: Expired due to Fees

• Current Assignee: Mke-Quantum Components Colorado LLC
• Original Assignee: Quantum Corporation (Chi Ko Investment Co., Ltd.)
• Inventors: Batra, Sharat
• Primary Examiner(s): Levy, Stuart S.
• Assistant Examiner(s): DITMYER, PAUL JOSEPH
• Application Number:
  US08/132,016
• Time in Patent Office: 595 Days
• Field of Search: 360/123, 360/125, 360/126, 29/603, 428/336
• US Class Current: 360/123.36
• 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: G11B 5/313 Disposition of layers
• CPC Class Codes: G11B 5/3163 Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic layers
• CPC Class Codes: Y10T 29/49034 Treating to affect magnetic properties
• CPC Class Codes: Y10T 29/49064 by coating
• CPC Class Codes: Y10T 29/49066 Preformed winding

Abstract

A thin film magnetic head, and process for making the same, features a thin film magnetic transducer formed from multiple layers of film and having a magnetic yoke interacting with an electrical coil. The yoke has multiple magnetic flux circuits, deposited on multiple layers of film, encircling the center of the transducer and connected together by proximal and distal vias. A coil has multiple turns intertwined with the yoke, passing between the distal and proximal vias so that the distal vias are exterior to the coil and the proximal vias are interior to the coil, to provide at least four magnetic flux interactions between the coil and the yoke. In preferred embodiments at least one layer of the film is deposited with at least two pole pieces having different easy axis orientations. In other preferred embodiments at least one distal via is configured as an elongated "flux strap" for conducting magnetic flux along the length of the via in a direction oblique to the easy axis of either pole piece coupled together by the magnetic flux strap.

Claims

1. A thin film magnetic transducer, comprising:

a pair of tip pole pieces each disposed in a corresponding separate one of two layers of said film and being adjacent to an air bearing surface of said transducer, each tip pole piece having a tip portion substantially aligned with a longitudinal axis perpendicular to said air bearing surface so that a magnetic read/write gap is thereby formed, each tip pole piece also having a body portion extending from said tip portion to a corresponding one of two frontal proximal vias traversing said layers at via locations between said air bearing surface and a center of said transducer, said body portions lying on opposite sides of said longitudinal axis and being formed such that each contains a linear flux conduction path forming a corresponding predetermined acute angle with respect to said longitudinal axis;

a yoke having three magnetic flux circuits disposed about the center of the transducer such that there is a rear magnetic flux circuit substantially centered on said longitudinal axis and two lateral magnetic flux circuits to either side thereof, each magnetic flux circuit having two pole pieces disposed in separate ones of said layers, each pole piece having a terminal end portion near the center of the transducer, the pole pieces being magnetically coupled together through an associated distal via traversing said layers away from the center of the transducer, each terminal end portion of said rear magnetic flux circuit being magnetically coupled to a corresponding terminal end portion of a corresponding one of said lateral magnetic flux circuits through a corresponding one of two rear proximal vias traversing the layers of the film near the center of the transducer behind said frontal proximal vias, the other terminal end portion of each of said lateral magnetic flux circuits being magnetically coupled to a corresponding one of said tip pole pieces through a corresponding one of said frontal proximal vias, each of said distal vias in said lateral magnetic flux circuits being sufficiently elongated so that (i) one end thereof extends at least to a line that extends through a corresponding nearest one of said frontal proximal vias and is substantially parallel to said flux conduction path in the tip pole piece lying on the opposite side of said longitudinal axis as said one end, and (ii) the other end thereof extends at least to a line that extends through a corresponding nearest one of said rear proximal vias and is substantially parallel to said flux conduction path in the tip pole piece lying on the same side of said longitudinal axis as said other end, said transducer being formed such that all pole pieces in the same layer as each of said tip pole pieces have an easy axis orientation substantially perpendicular to said flux conduction path therein; and

a coil having a plurality of turns intertwined with the yoke and passing between the distal and proximal vias, so that the distal vias are exterior to the coil and the proximal vias are interior to the coil, to provide at least four magnetic flux interactions between the coil and the yoke.

2. The thin film magnetic transducer of claim 1, wherein the angle between the flux conduction path and said longitudinal axis is the same for each of said tip pole pieces.

3. The thin film magnetic transducer of claim 2, wherein said angle is between 25 and 45 degrees.

4. The thin film magnetic transducer of claim 3, wherein said angle is substantially equal to 35 degrees.

5. The thin film magnetic transducer of claim 1, wherein each of said elongated distal vias is substantially parallel to said longitudinal axis.

6. The thin film magnetic transducer of claim 1, wherein said one end of each of said elongated distal vias extends substantially to a line that is parallel to said air bearing surface and extends through the point where said body portions of said tip pole pieces intersect.

7. A thin film magnetic transducer, comprising:

a pair of tip pole pieces each disposed in a corresponding separate one of two layers of said film and being adjacent to an air bearing surface of said transducer, each tip pole piece having a tip portion substantially aligned with a longitudinal axis perpendicular to said air bearing surface so that a magnetic read/write gap is thereby formed, each tip pole piece also having a body portion extending from said tip portion to a corresponding one of two frontal proximal vias traversing said layers at via locations between said air bearing surface and a center of said transducer, said body portions lying on opposite sides of said longitudinal axis and being formed such that each contains a linear flux conduction path forming a substantially 35 degree angle with respect to said longitudinal axis;

a yoke having three magnetic flux circuits disposed about the center of the transducer such that there is a rear magnetic flux circuit substantially centered on said longitudinal axis and two lateral magnetic flux circuits to either side thereof, each magnetic flux circuit having two pole pieces disposed in separate ones of said layers, each pole piece having a terminal end portion near the center of the transducer, the pole pieces being magnetically coupled together through an associated distal via traversing said layers away from the center of the transducer, each terminal end portion of said rear magnetic flux circuit being magnetically coupled to a corresponding terminal end portion of a corresponding one of said lateral magnetic flux circuits through a corresponding one of two rear proximal vias traversing the layers of the film near the center of the transducer behind said frontal proximal vias, the other terminal end portion of each of said lateral magnetic flux circuits being magnetically coupled to a corresponding one of said tip pole pieces through a corresponding one of said frontal proximal vias, each of said distal vias in said lateral magnetic flux circuits sufficiently elongated in a direction substantially parallel to said longitudinal axis so that (i) one end thereof extends at least to a line that extends through a corresponding nearest one of said frontal proximal vias and is substantially parallel to said flux conduction path in the tip pole piece lying on the opposite side of said longitudinal axis as said one end, and also extends substantially to a line that is parallel to said air bearing surface and extends through the point where said body portions of said tip pole pieces intersect, and (ii) the other end thereof extends at least to a line that extends through a corresponding nearest one of said rear proximal vias and is substantially parallel to said flux conduction path in the tip pole piece lying on the same side of said longitudinal axis as said other end, said transducer being formed such that all pole pieces in the same layer as each of said tip pole pieces have an easy axis orientation substantially perpendicular to said flux conduction path therein; and

a coil having a plurality of turns intertwined with the yoke and passing between the distal and proximal vias, so that the distal vias are exterior to the coil and the proximal vias are interior to the coil, to provide at least four magnetic flux interactions between the coil and the yoke.