| 摘要 |
PURPOSE:To remove a foreign matter of ferromagnetic metallic powder adhered on a base by providing a running drive system driving a long nonmagnetic base in a vacuum tank and a magnet in the vicinity of the nonmagnetic base at the position of this side of the nonmagnetic base being driven where a ferromagnetic metallic thin film is formed. CONSTITUTION:A nonmagnetic base 2 is driven in close contact with a can roll via a guide roll 6 from the supply roll 3 and wound on a winding roll 5 via a guide roll 7. Then, the ferromagnetic metal from an evaporation source 8 is evaporated onto the nonmagnetic base 2 driven in close contact with the can roll 4 to form a thin film. The ferromagnetic metallic atoms emitted from the evaporation source 8 are adhered also to an inner wall of the vacuum tank 1 in addition to the nonmagnetic base 2, and the metal is exfoliated from the inner wall and floated in the vacuum tank 1 as fine powder, but the magnet 9 attracts and removes the ferromagnetic metallic powder adhered onto the nonmagnetic base 2 at a position this side where the ferromagnetic metallic thin film is formed to the base 2. Thus, the production of projection on the surface of a metallic thin film magnetic recording medium is prevented.
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