PRODUCTION OF MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To obtain a magnetic recording medium having good durability by forming the medium in such a manner that two sputtering sources exist within the virtual plane when at least one virtual plane parallel with the conveying direction of the substrate and perpendicular to a sputtering target platen is considered and that specific conditions are satisfied in said plane. CONSTITUTION:A Co-Cr magnetic recording layer 7 is formed by disposing the flexible conveying substrate 3 and and Co-Cr target 1 in such a manner that the two sputtering sources 5, 6 exist within the virtual plane parallel with the conveying direction of the substrate 3 and perpendicular to the target 1 plane. Two masks 8, 9 are provided between the Co-Cr target 1 and the substrate 3. The point O where the formation of the magnetic layer by the mask 8 is started corresponds to the surface of the substrate 3 right under the end of the substrate 3. The mask 8 is so installed as to attain theta2>theta1 when the angle between the normal OO' to the surface of the substrate 3 at the point O and the line OA connecting the point O and the central point A of the sputtering source 5 is theta1 and the angle between the normal OO' and the line OB connecting the point O and the central point B of the sputtering source 6 is designated as theta2.