Seagate Technology Incorporated

Hitachi Metals, Ltd.

Applied Magnetics, LLC

Simon H Liao

Beat G Keel

Chiharu Mitsumata

Arthur Calderon

Masahiro Tobise

Tetsurou Kawai

Hisayuki Miura

An SAL-type magnetoresistive playback head that is highly sensitive and that limits Barkhausen noise is provided by optimizing the magnetic properties of the permanent magnet film. On top of a lower insulating layer are stacked a soft magnetic bias film (SAL film), a magnetic separating film (shunt film), a magnetoresistive film (MR film), and an upper insulating layer, in that order. The outer sides of the track of the MR film are in direct contact with the permanent magnet film or in indirect contact via a base film. Alternatively, the present invention relates to a spin-valve magnetoresistive playback head. On top of a lower insulating layer are stacked an anti-ferromagnetic film, a fixed magnetizing film, a magnetic separating film, a movable magnetizing film (MR film), and an upper insulating layer, in that order. The outer sides of the track of the movable magnetizing film are in direct contact with the permanent magnet film or in indirect contact via a base film. In either type of playback head, Barkhausen noise is eliminated by using a CoCrPt alloy film having a composition that provides the magnetic properties needed for a permanent magnet film that can handle narrow tracks and narrow gaps, and by specifying a ratio between the thicknesses of the MR film and the permanent magnet film.

Magnetoresistive playback head

A laminated thin film magnetic head having nickel phosphorus layers sandwiched between layers of nickel iron. The nickel iron layers preferably have zero magnetostriction. The nickel phosphorus layer may comprise NiPX where X is one or more of the following: tungsten, boron, copper or molybdenum. Multiple laminations may be employed.

Laminated leg for thin film magnetic transducer

A thin film magnetic read/write head has a copper iron boron core. Cobalt, iron and boron are included in the electroplating bath used to form the pole pieces of the thin film magnetic head. Following exposure to a rotating magnetic field, the pole pieces have high saturation magnetization, low coercivity, low anisotropy and large permeability.

High magnetic moment thin film head core

A thin film magnetic read/write head has a cobalt iron boron core. Cobalt, iron and boron are included in the electroplating bath used to form the pole pieces of the thin film magnetic head. Following exposure to a rotating magnetic field, the pole pieces have high saturation magnetization, low coercivity, low anisotropy and large permeability.

Thin film core of Co-Fe-B alloy

In a method of manufacturing a thin film magnetic head having aligned top and bottom pole tip pieces, a sacrificial mask protects the upper pole tip while the exposed non-aligned portions of the gap material and lower pole tip are removed. The sacrificial mask is deposited using a self alignment technique.

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Santa Barbara, CA, United States of America

Simon H Liao