Abstract: A method for manufacturing a semiconductor module incorporated with an optical isolator making use of a Faraday rotator formed of a magnetic garnet film in which a magnetically saturated condition is maintained even without any external magnetic field, in which, at the time the magnetic garnet film is exposed to a temperature of 100° C. or more in a step during manufacture, an external magnetic field is applied in the same direction as the direction of magnetization of this magnetic garnet film. This manufacturing method has an advantage that the high-coercivity film magnetic garnet film is not removed from its magnetically saturated condition even when heating steps are present in the course of manufacture.

Abstract: A method for manufacturing a semiconductor module incorporated with an optical isolator making use of a Faraday rotator formed of a magnetic garnet film in which a magnetically saturated condition is maintained even without any external magnetic field, characterized in that, at the time the magnetic garnet film is exposed to a temperature of 100° C. or more in a step in the course of manufacture, an external magnetic field is applied in the same direction as the direction of magnetization of this magnetic garnet film. This manufacturing method has an advantage that the high-coercivity film magnetic garnet film is not removed from its magnetically saturated condition even when heating steps are present in the course of manufacture.

Abstract: A magnetic disc manufacturing apparatus is includes a polishing device for conducting a surface polishing treatment on a disc, a supply device for supplying lubricant onto the polished disc, and a feeding mechanism for feeding the disc between the devices. If necessary, it is provided with a curing device for curing the lubricant on the disc. The treatments of the devices and the disc feeding operation are synchronized with one another, and a disc processed in each device is fed to a next device at a constant time interval by the feeding mechanism, thereby performing a continuous disc manufacturing process.

Abstract: A process for fabricating a magnetic disk which comprises texturing a magnetic disk substrate made of a non-magnetic material having provided on the surface thereof a hard layer of a metal or an oxide to thereby provide fine irregularities on the surface of said substrate, followed by establishing thereon a magnetic recording layer comprising a film of a ferromagnetic metal, wherein said texturing is carried out using a processing solution comprising an aqueous solution of a surface active agent having dispersed therein diamond abrasive grains substantially only not larger than 4 .mu.m in grain diameter.