Thin film magnetic head having a pair of magnetic layers whose magnetization is controlled by shield layers

A thin film magnetic head comprising:

• a Magneto Resistance (“MR”) laminated body composed of a first MR magnetic layer whose direction of magnetization changes in response to an external magnetic field, a nonmagnetic middle layer and a second MR magnetic layer whose direction of magnetization changes in response to an external magnetic field, wherein the first MR magnetic layer, the nonmagnetic middle layer and the second MR magnetic layer are in contact with each other in the order;
• first and second shield layers which are provided facing the first MR magnetic layer and the second MR magnetic layer, respectively, and which are arranged in a manner of sandwiching the MR laminated body in an orthogonal direction relative to a film surface of the MR laminated body, and also which function as electrodes for flowing a sense current in the orthogonal direction relative to the film surface of the MR laminated body;
• and
• a bias magnetic field application layer provided on an opposite side of an air bearing surface (ABS) of the MR laminated body in order to apply a bias magnetic field orthogonal relative to the ABS, wherein
• the first shield layer comprises:
• a first exchange coupling magnetic field application layer which is provided facing the first MR magnetic layer and which applies an exchange coupling magnetic field to the first MR magnetic layer in a direction parallel to the ABS;
• and
• a first antiferromagnetic layer which is provided in contact with the first exchange coupling magnetic field application layer on the rear face of the first exchange coupling magnetic field application layer seen from the first MR magnetic layer and which is exchange coupled with the first exchange coupling magnetic field application layer, and
• the second shield layer comprises:
• a second exchange coupling magnetic field application layer which is provided facing the second MR magnetic layer and which applies an exchange coupling magnetic field to the second MR magnetic layer, the exchange coupling magnetic field being in a parallel direction to the ABS and in an antiparallel direction to an exchange coupling magnetic field applied to the first MR magnetic layer by the first exchange coupling magnetic field application layer, and
• a second antiferromagnetic layer which is provided in contact with the second exchange coupling magnetic field application layer on the rear face of the second exchange coupling magnetic field application layer seen from the second MR magnetic layer and which is exchange coupled with the second exchange coupling magnetic field application layer,
• wherein the first exchange coupling magnetic field application layer, the first antiferromagnetic layer, the second exchange coupling magnetic field application layer and the second antiferromagnetic layer are longer than the MR laminated body both in a track width direction and in a direction perpendicular to the ABS,
• wherein the bias magnetic field application layer is positioned between the first exchange coupling magnetic field application layer and the second exchange coupling magnetic field application layer, as viewed in a laminating direction of the MR laminated body.