Magnetic head and method of production thereof

摘要

A magnetic head and a production method therefore in which permanent magnet films for applying a DC bias magnetic field Hd h to a magnetoresistive effect element film (MR element film) is arranged on both sides of the thickness dimension of the MR element film through at least a non-magnetic film therebetween. In making the MR element film thicker in order to reduce distortion, the DC bias magnetic field Hd b to be applied to the MR element film is also required to be increased. Unlike the prior art in which the above-mentioned requirement is met by increasing the thickness of the permanent magnet film under the thickness of the MR element film resulting in the problem of breakage of a film member above or under the thickness of the permanent magnet film, the invention further comprises a second permanent magnet film above the thickness of the MR element film without increasing the thickness of the first permanent magnet film. In the case of a magnetic head with a shield members of soft magnetic material holding the MR element film from both sides of the thickness thereof, the MR element film is made thicker to make reproduction possible without any distortion or without substantially increasing the gap. For this purpose, the MR element film is held on the sides above and under the thickness thereof by first and second permanent magnet films which in turn are held by the shield members. To minimize distribution of the MR element film, a comparatively high-temperature process after forming of the MR element film i.e., forming of the second permanent magnet film is effected at optimum temperature, and a magnetic field is applied along the magnetic easy axis of the MR element film.