Abstract: Provided is a polysiloxane composition containing a polysiloxane compound including a constitutional unit represented by Formula (1) and at least one of a constitutional unit of Formula (2) and a constitutional unit of Formula (3), and a solvent. [(Rx)bR1mSiOn/2]??(1) [(Ry)cR2pSiOq/2]??(2) [SiO4/2]??(3) Here, Rx is a monovalent group represented by Formula (1a) (X is a hydrogen atom or an acid-labile group, a is an integer of 1 to 5, and a broken line represents a bond), Ry is a monovalent organic group having 1 to 30 carbon atoms, which contains any one of an epoxy group, an oxetane group, an acryloyl group, and a methacryloyl group.

Abstract: Provided is a production method for producing an aromatic alkoxysilane containing a hexafluoropropanol group (—C(CF3)2OH; referred to as HFIP group) from an inexpensive starting raw material with a high reaction conversion rate and selectivity. As shown in the following scheme, the production method includes: a first step of reacting an aromatic halosilane with hexafluoroacetone in the presence of a Lewis acid catalyst, thereby obtaining a HFIP group-containing aromatic halosilane; and a second step of forming the HFIP group-containing aromatic alkoxysilane by reacting the HFIP group-containing aromatic halosilane with an alcohol.

Abstract: According to one aspect of the present invention, there is provided a curable resin composition including at least: a polysiloxane compound having, in a molecule thereof, at least two functional groups selected from the group consisting of silanol groups and alkoxysilyl groups as a component (A-1); and silica whose extract water has a pH of 6.1 or lower at 25° C. as a component (B), wherein the amount of the component (B) relative to the total amount of the components (A-1) and (B) is in a range of 70 to 97 mass %. This curable resin composition is able to, even when formed into various shapes and sizes, prevent foaming during curing and thus is suitable as an encapsulant material for a semiconductor element.

Abstract: According to one aspect of the present invention, there is provided a curable resin composition including at least: a polysiloxane compound having, in a molecule thereof, at least two functional groups selected from the group consisting of silanol groups and alkoxysilyl groups as a component (A-1); and silica whose extract water has a pH of 6.1 or lower at 25° C. as a component (B), wherein the amount of the component (B) relative to the total amount of the components (A-1) and (B) is in a range of 70 to 97 mass %. This curable resin composition is able to, even when formed into various shapes and sizes, prevent foaming during curing and thus is suitable as an encapsulant material for a semiconductor element.

Abstract: A magnetic disc apparatus has a large recording density of 120 megabits per square inch or more, and defines a relationship among a pole thickness (Pt) of thin-film magnetic heads disposed in the magnetic disc apparatus, and a saturation flux density (Bs) of cores of the heads and a recording wavelength (.lambda.) for the thin film magnetic discs have a coercivity of 1800 Oe or more, wherein a levitation space between the head and the disc is 0.15 .mu.m or less.

Abstract: A magnetic lamination including at least a first magnetic film, a second magnetic film and, a third magnetic film, a first intervening intermediate film intervening between the first and second magnetic films, and a second intervening intermediate film intervening between the second and third magnetic films, wherein the respective magnetic films each comprise a magnetically soft film, the first and second intervening films differ in thickness, and one of the first and second intervening films can have a zero thickness and further, the intervening intermediate film can include a transition metal and a substance which is likely to form a heterogeneous mixture with the transition metal.

Abstract: An optical information handling device in which reflectivity of the conventional reproduction-only type optical disk is lowered to 60% or less and is made equal to the reflectivity of write-once type and rewritable type optical disks, whereby interchangeability in these of these disks is possible.

Abstract: A magnetic recording device includes a magnetic disk for storing information, a magnetic head for writing and reading information relative to the magnetic disk, a device for rotating the magnetic disk relative to the magnetic head in such a manner that speed of said magnetic disk relative to the magnetic head is 6 to 40 m/s at an innermost track of the magnetic disk, and a device for applying a load to the magnetic head so that a gap between the magnetic disk and the magnetic head disposed in opposed relation to the magnetic disk can be kept to not more than 0.1 .mu.m.

Abstract: The information processor uses a portable memory formed on a transparent substrate which is able to be overwritten by laser power modulation system. The memory includes a disk type recording medium rotatably incorporated within a thin case, and carries out write/read/erase by means of a first magnetic field application device, a second magnetic field application device, and an optical head radiating light through the case which has at least a transparent light-incident portion. The case includes therein a rotation means for rotating the recording medium within the case, thereby enabling even further reduction in size of the information processor.

Abstract: The invention relates to an optical memory in which an optical recording medium is built in a case, and also to a memory apparatus. Recording, reproducing and erasing operations are performed by irradiating light via a transparent portion of the case onto the built-in optical recording medium. The optical recording medium built in the case has face vibrations with respect to the case, because it is moved within the case. The present invention is characterized by employing such a construction for optically mitigating irregular fluctuation in reflectivity caused by this face vibration. In the optical memory of the present invention, the reflectivity fluctuation caused by an interference effect made between reflection light from the case and air, and also reflection light from the optical recording medium and air due to the relative deviation in the face vibrations, may be reduced by antireflection films provided in the case and the optical recording medium.

Abstract: An LSI mounting substrate having a multilayered thin film wiring portion, with the thin film wiring portion being divided into wiring units each composed of a plurality of wiring layers, with the wirings between the units being electrically connected through connecting pads defined in the same surface as that of a surface conductive layer of the unit.

Abstract: There is provided a compact and thin optical disk unit as a memory unit suitable for a portable computer such as a book type computer and a portable recording/reproducing apparatus. In the optical disk unit, the diameter of an objective lens is limited and a beam shaping prism, a beam splitter, a mirror and a 1/4 wavelength plate are formed into a unitary structure to make easy the optical axis adjustment of an optical head and ensure highly accurate assembling.

Abstract: A thin film magnetic head comprising a substrate on which are successively formed a base layer, a lower magnetic film, a gap layer, an insulator layer, a conductor coil, an upper magnetic film, and a first mask, is manufactured by a method in which one or more of a gas which can be expressed by the general formula of CnHxFy (where n.gtoreq.1, x+y=2n+2, x>0, y>0, and x.gtoreq.y); and a gas which can be expressed by the general formula of CnHxFy (where n.gtoreq.1, x+y=2n+2, x.gtoreq.0, y.gtoreq.0, and x<y) is used. The structure of the magnetic head thus obtained is such that, at a height near the interface between the mask and the upper magnetic film provided therebelow, the angle defined by the side edge surfaces of the mask and the above-mentioned interface ranges from 75.degree. to 90.degree..

Abstract: A magnetic recording apparatus for recording information on a magnetic recording medium. A circuit for generates a recording current pulse train and supplies the pulse train to a magnetic head. The last pulse of the recording current pulse train dampled waveform. A ripple current is superposed on the damped waveform.

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: The information processor uses a portable memory which is able to be overwritten by laser power modulation system. The memory includes a disk type recording medium incorporated rotatably in a thin case, and carries out write/read/erase by means of a first magnetic field application device, a second magnetic field application device, and an optical head radiating light through this case.

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: This invention provides a magnetic disk device having a total memory capacity of 30 giga bytes or more, or more desirably 30.about.40 giga bytes. The magnetic disk used in this magnetic disk device has a plane record density of 45.about.80 mega bits per square inch. The thin film magnetic head has a pole thickness (P.sub.T), a magnetic flux density (B.sub.s), a magnetic gap depth (G.sub.d) and a record wavelenth (.lambda.) which satisfy the formulaG.sub.d .ltoreq.0.13 P.sub.T B.sub.s (.lambda.+4.3)-2.1.The magnetic disk rotation means rotate the magnetic disk at a speed of 24 m per second or more.

Abstract: A thin film magnetic head has magnetic films, at least one of which is composed of a material containing major components of nickel and iron and one or more element from nitrogen, oxygen and carbon and has two of face-centered cubic system and body-centered tetragonal system, whereby thin film magnetic heads having a high permeability and low coercive force can be provided.

Abstract: A magneto-optical recording medium made of a rare-earth-transition metal amorphous film provides a compensation temperature Tcomp of 50.degree.-200.degree. C. or 0.degree. C. or less. This compensation temperature decreases a saturation magnetization Ms during recording, thereby preventing the provision of inverted magnetic domains at the centers of recording domains resulting from the demagnetizing field generated by the strength distribution of laser light, and so improving a carrier-to-noise ratio during reading. In the case of using a Tb-Fe-Co system amorphous film, Tcomp of 50.degree.-200.degree. C. may be give by the composition comprising Tb of 24-30 atomic %, Co of 7-20 atomic % and Fe of the rest, and Tcomp of 0.degree. C. or less may be given by the composition comprising Tb of 18-21.5 atomic %, Co of 8-10 atomic % and Fe of the rest.