PRODUCTION OF COMPOSITE SUBSTRATE FOR THIN FILM MAGNETIC HEAD

摘要

PURPOSE:To produce easily a laminated thin film magnetic head by interposing a specified nonmagnetic oxide ceramic sheet and a glass sheet between soft ferrite sheets whose mirror-finished principal planes are opposed to each other, laminating and forming the material by heating and compressing and then polishing the outer principal plane of ferrite. CONSTITUTION:A nonmagnetic oxide ceramic sheet 3 having a thermal expansion coefficient which differs from the thermal expansion coefficient of a soft ferrite sheet by <=1X10<-6>/deg and whose both surfaces are mirror-finished is interposed between the 2 soft ferrite sheets 1 and 2 whose mirror-finished principal planes are opposed to each other and further laminated and stuck through a glass sheet 4 having 400-850 deg.C softening point and a thermal expansion coefficient which differs from the thermal expansion coefficient of the ferrite sheet by <=1X10<-6>/deg between the soft ferrite sheet and the ceramic sheet. The material is then laminated and formed by heating the material to a temp. at which the viscosity of the glass sheet becomes 10<3>-10<7.6> poise or further the hot formed body is hydrostatically pressed. Then the outer principal plane of each soft ferrite is polished to <=200Angstrom surface roughness and a composite substrate consisting of 3 principal layers can be manufactured. A bulk-type thin film magnetic head can be thus manufactured.