Hitachi Metals, Ltd.

Masanobu Yamazaki

Ryo Goto

Manabu Toyoda

Fumio Nitanda

Makoto Ushijima

Kazumi Noguchi

Tadafumi Tomitani

Chiharu Mitsumata

Hitoshi Iwata

Keiichi Kondo

A floating type composite magnetic head includes a slider, having an air bearing surface, made of a non-magnetic substance, a magnetic head core which is formed of a pair of magnetic cores defining a magnetic gap, or a pair of magnetic cores having a magnetic gap defined by a butting surface on which is formed a magnetic metallic thin film, and is fixed by bonding glass in a groove provided in a flow-out end of the air bearing of the slider, excitation coils wound in a window section of the head core, and a front gap surface of the magnetic head core being placed so as to oppose the magnetic recording medium. The magnetic head core back surface and the slider rear surface are formed as to be flush at least in the vicinity of the groove, and preferably have a maximum surface roughness of 3 to 8 .mu.m.

Floating type magnetic head having flush rear reference surface

In a floating magnetic head, noises produced at the time of reproduction are reduced, thereby enhancing the precision of detection of a track position. The floating magnetic head uses a monocrystal magnetic material constituting an electromagnetic transducer element, and a crystal orientation of the monocrystal magnetic material in the electromagnetic transducer element is parallel to a direction of travel of a medium. In the case of .vertline..lambda..sub.111 .vertline.+2.times.10.sup.-6 .ltoreq..vertline..lambda..sub.100 .vertline., the crystal orientation is in the range of a solid angle of 3.multidot.sin.theta..multidot.cos.phi. which satisfies 0.ltoreq..theta.&lt;10 degrees and 0.ltoreq..phi..ltoreq.360 degrees around [111], and in the case of .vertline..lambda..sub.111 .vertline..gtoreq..vertline..lambda..sub.100 .vertline.+2.times.10.sup.-6, the crystal orientation is in the range of a solid angle of sin .theta..multidot.cos.phi. which satisfies 0.ltoreq..theta.&lt;10 degrees and 0.ltoreq..phi..ltoreq.360 degrees around [100], where .lambda..sub.111 and .lambda..sub.100 respectively represent linear magnetostriction constant of the monocrystal magnetic material in directions &lt;111&gt; and &lt;100&gt;. The monocrystal magnetic material is a monocrystal MnZn ferrite whose chemical composition is represented by 20.ltoreq.MnO.ltoreq.40, 10.ltoreq.ZnO.ltoreq.25 50.ltoreq.Fe.sub.2 O.sub.3 .ltoreq.65 in terms of mol. %.

Floating magnetic head with reduced magnetostriction vibration noise

A bonding glass for assembling a magnetic head by bonding a magnetic core to a non-magnetic ceramic slider. The magnetic core has a gap and an Fe-Al-Si film within the gap. The bonding glass includes SiO.sub.2 in the range of 6 to 11 wt %, B.sub.2 O.sub.3 in the range of 5 to 9 wt %, Al.sub.2 O.sub.3 in the range of 2 to 5 wt %, PbO in the range of 55 to 70 wt %, Bi.sub.2 O.sub.3 in the range of 5 to 15 wt %, TeO.sub.2 in the range of 1 to 10 wt % and CuO in the range of 0.5 to 2 wt %. A part of the PbO in PbO-SiO.sub.2 -B.sub.2 O.sub.3 -Al.sub.2 O.sub.3 glass is replaced with TeO.sub.2 and Bi.sub.2 O.sub.3 and, at the same time, CuO is added in order to prevent the formation of a heterophase. Glass color change under high temperature and high humidity is prevented.

Bonding glass for assembling a magnetic head, and a magnetic head

A floating magnetic head comprises a pair of magnetic core pieces which face each other through a gap and a metal magnetic film formed on the surface facing the gap of one of the pair of magnetic core pieces. The pair of magnetic core pieces are made of a single crystal Mn-Zn ferrite, a plane of the magnetic core pieces being formed almost in parallel with the surface forming a main magnetic path, and a &lt;100&gt; direction in the plane being formed to meet a relation of an angle .theta. to be 26.degree.&lt;.theta..ltoreq.45.degree. between the &lt;100&gt; direction and the surface facing the gap.

Flying type composite magnetic head having Mn-Zn ferrite core

A flying-type composite magnetic head includes (a) a magnetic core constituted by a pair of core pieces bonded together by a first glass portion, at least one of opposing surfaces of the core pieces being formed with a thin magnetic metal layer; (b) a non-magnetic slider having a slit for receiving the magnetic core; and (c) a second glass portion for fixing the magnetic core in the slit; the first glass portion having a softening point lower than a first bonding temperature by 70.degree. C. or more and a yielding temperature higher than a second bonding temperature, and the second glass portion having a softening point lower than a second bonding temperature by 70.degree. C. or more. The first bonding temperature T.sub.1 (.degree.C.) for forming the first glass portion satisfies the following relation:

Method of producing a fly-type composite magnetic head with appropriate

A flying-type composite magnetic head includes (a) a magnetic core constituted by a pair of core pieces bonded together by a first glass portion, at least one of opposing surfaces of the core pieces being formed with a thin magnetic metal layer; (b) a non-magnetic slider having a slit for receiving the magnetic core; and (c) a second glass portion for fixing the magnetic core in the slit; the first glass portion having a softening point lower than a first bonding temperature by 70.degree. C. or more and a yielding temperature higher than a second bonding temperature, and the second glass portion having a softening point lower than a second bonding temperature by 70.degree. C. or more. The first bonding temperature T.sub.1 .degree.C.) for forming the first glass portion satisfies the following relation:

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Mooka, Japan

Masanobu Yamazaki