Evaluation method of film magnetic head

Abstract

To obtain an evaluating method of a thin film magnetic head in which a quality of an output property can be evaluated highly accurately by eliminating defective products possibly causing degradation and instability. In the thin film magnetic head having an antiferromagnetic layer, a fixed magnetic layer, a non-magnetic conduction layer, a spin valve film obtained by laminating free magnetic layers, and a hard bias film contacted to both sides of a track width direction of the spin valve film, first, the hard bias film is magnetized in the direction of track width of the hard bias film (first magnetization process), an alternating electric field is applied and the head output property is measured (first measuring process). Next, after the hard bias film is magnetized in the height direction being orthogonal to the track width direction, processing for magnetization in the track width direction is performed at least once, the alternating electric field is applied with the same condition as the first time and the head output property is measured (second measuring process). The quality of the head output property is discriminated by comparing the first time measured result with the second time measured result.

Description

technical field [0001] The present invention relates to an evaluation method of a thin-film magnetic head for domain control using a hard bias film. Background technique [0002] In a thin-film magnetic head, a characteristic inspection is performed to confirm whether or not the predetermined basic specifications as a product are satisfied at the manufacturing stage or before shipment. As this characteristic inspection, QST (Quasi Static Test) evaluation test is generally used. The QST evaluation test is a method for evaluating the reproduction output characteristics and magnetic stability of a thin-film magnetic head without using an actual magnetic recording medium. Specifically, the element voltage-external magnetic field characteristic curve (V-H curve) of the thin film magnetic head was obtained by periodically changing an external magnetic field of 3.98 to 39.8 kA / m in the state of energizing the thin film magnetic head (magnetoresistive effect element). Then, based ...

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Problems solved by technology

[0006] However, even thin-film magnetic heads that have passed the above-mentioned QST evaluation test and DET evaluation test may experience degradation and instability after the test, deteriorating the yield of hard disk devices equipped with the thin-film magnetic head.

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