Abstract: A method of fabricating a thin-film magnetic in which a mask pattern in etching a bottom pole is formed of first and second mask films in this order when viewed from the bottom pole, the first mask film is used for defining, by self-alignment, the length of that portion of the side edge of a top pole which is nearly perpendicular to a magnetic gap, the second mask film makes it possible to etch the bottom pole with high dimensional accuracy, a non-magnetic film is formed on the mask pattern having the bottom pole thereunder and the exposed region of a substrate, and the top pole is formed after the mask pattern has been exposed and removed.

Abstract: A magnetic disc apparatus includes a magnetic disc for recording information; a thin film magnetic head including a magnetic pole structure having an upper magnetic pole tip and a lower magnetic pole tip arranged to provide a magnetic gap at respective end portions thereof for writing and reading information in and from the magnetic disc; a device for rotating the magnetic disc; and a device for positioning the thin film magnetic head; the upper and lower magnetic pole tips having different contours at the respective end portions as viewed from a side confronting the magnetic disc wherein the difference (.DELTA.CW in .mu.m) in the width, along the magnetic gap, of the upper magnetic pole tip and the width, along the magnetic gap, of the lower magnetic pole tip satisfies the relation0<.DELTA.CW.ltoreq.5000/Trfor the magnetic disc having a track density Tr of 1800 or more tracks per inch.

Abstract: A magnetic head for reading from and/or writing to a magnetic information storage medium has a substrate on which a plurality of thin films are formed in sequence. The films provide a magnetic circuit having a magnetic gap, a bottom pole piece and a top pole piece overlying said bottom pole piece. The top pole piece is formed as a tip portion adjoining the magnetic gap and a rear portion which makes magnetic contact with the tip portion. The rear portion is formed in the sequence after the tip portion. To ensure accurate thickness and width of the tip portion, a non-magnetic protective film is formed on the tip portion after the tip portion is formed and before the rear portion is formed.

Abstract: A thin film magnetic head including conductor coils, a plurality of insulating layers to interpose and insulate the conductor coils and a magnetic gap layer between upper and lower magnetic cores, in which another insulating layer is provided on a stepped region formed by end faces of the plurality of insulating layers.

Abstract: A method of producing a thin film magnetic head by successively depositing on a substrate a first magnetic material, a gap material, an electrically conductive material consisting of a coil, an insulating film, a second magnetic material and a protecting film, wherein the improvement comprises a step for forming a recessed portion in the insulating film at a portion corresponding to a gap portion on the air bearing surface side, the bottom surface of said recessed portion serving as an exposed portion on the upper surface of the gap material and the side surfaces of said recessed portion being tapered, a step for forming a recessed portion in the gap material by etching using the insulating film with the recessed portion as a mask and making the thickness thereof equal to the gap length, and a step for depositing a second magnetic material on the whole surface, so that the recessed portion formed in the gap material will have a rectangular shape with its one side being equal to a gap depth and its another sid

Abstract: A thin film magnetic head having two conductor layers provided within a magnetic circuit constituted by a first and a second magnetic member. The magnetic circuit has, at the side to which a recording medium is opposed, a portion where the first and second magnetic members are opposed to each other over a length substantially equal to a gap depth, intervening a non-magnetic gap member therebetween, and a portion ahead thereof where they are connected with each other. The edge of the gap member constitutes an aperture of the magnetic circuit. The thin film magnetic head arranged as above permits a high density recording without reducing its production yield.

Abstract: A thin film magnetic head of which the insulation layer is made of a polyimide resin obtained by heat-curing a polyimide precursor represented by the following general formula (I) or (II) or a mixture thereof not only has excellent characteristics with respect to the insulation layer, i.e. satisfactory flatness, high glass transition temperature and excellent adhesiveness but also is free from film defects, i.e., exhibits high reliability: ##STR1## wherein R is, e.g., ##STR2## Ar.sup.1 is, e.g., ##STR3## Ar.sup.2 is, e.g. ##STR4## n is an integer of 1 to 100, and m is an integer of 10 to 500.

Abstract: A thin-film magnetic head having a magnetic core of double step structure and a method of fabricating it. A first magnetic core is formed on a substrate, which has a predetermined thickness at a pole chip region thereof and a thickness larger than the predetermined thickness at a back region thereof; a magnetic gap is formed thereon, a conductor coil is formed on the magnetic gap, which is encircled by an inter-layer, insulating film; a first magnetic film is formed thereon, which constitutes one layer of a second magnetic core and is connected with the first magnetic core at the back region; and a second magnetic film is formed thereon through an inorganic insulating film, which constitutes another layer of the second magnetic core and is removed at the pole chip region. When the second magnetic film is removed, the inorganic insulating film serves to protect the first magnetic film, and hence the thickness of the first magnetic film is maintained unvaried.