Abstract: A thin-film magnetic head for perpendicular magnetic recording according to the present invention comprises a coil to generate a magnetic field, and a main pole layer to perform the perpendicular recording using the magnetic field generated by said coil. The lower surface as to the layer-forming direction of said main pole layer has irregularities at the medium-facing surface side end.

Abstract: The present invention is directed to a thin-film magnetic head having no ATE problem, a very narrow track width, an excellent O/W characteristic and a high switching speed. A lower pole film of a write element is provided on one face of a lower yoke film inside a trench portion provided in an inorganic insulating film. A gap film and an upper pole film are provided inside the trench portion on the lower pole portion. The trench portion has preferably an attached film made of an inorganic material on the inner wall faces facing the side faces of said lower pole film, said gap film and said upper pole film.

Abstract: A method for testing a TMR element includes a step of measuring a plurality of resistances of the TMR element by feeding a plurality of sense currents with different current values each other through the TMR element, a step of calculating a ratio of change in resistance from the measured plurality of resistances of the TMR element, and a step of evaluating the TMR element using the calculated ratio of change in resistance.

Abstract: An HGA includes a magnetic head slider provided with at least one thin-film magnetic head element, and a conductive suspension to which the magnetic head slider is fixed. A conductive resistance between the magnetic head slider and the suspension is equal to or higher than 1 M?.

Abstract: At least the first chamfered portion 22 for forming the apex portion 8 has a surface roughness (R.sub.p-p) of 0.6 .mu.m or under. This first chamfered portion 22 is formed through grinding with a #2500 or #1500 grinding stone.

Abstract: A magnetic head is provided with an apex portion having a first and second chamfered portion, both formed in a C core. The first chamfered portion has a first apex angle .alpha. at a position corresponding to a predetermined gap depth. The first chamfered portion also has a predetermined apex length. The second chamfered portion is contiguous to the first chamfered portion and has second apex angle .beta. which is smaller than the first apex angle .alpha.. The first apex angle .alpha. is greater than or equal to 70.degree. and less than 80.degree..

Abstract: A flying magnetic head is provided in which a head core, formed by laminating a magentic thin film on a non-magnetic substrate, is fitted into a slot formed in a slider through a bonding glass layer. The substrate of the head core and the slider are formed from the same material. The coefficient of thermal expansion of the head core substrate is substantially the same as that of the magnetic thin film. The thickness of the bonding glass layer which bonds the head core to the slider is reduced to 20 .mu.M or less.