PURPOSE: To obtain many master stampers from a sheet of an original disk without giving any damage to the projecting/recessing pattern of the original disk, by applying the conductivity and plating to the surface of a polymer replica and then exfoliating the plated metallic layer from the surface of the replica.
CONSTITUTION: A photoresist layer 3' is deleted after etching an inorganic coated layer with the layer 3' used as a mask, and therefore a projecting/recessing pattern is formed to the inorganic coated layer. Thus the 1st original disk 6 is obtained. A rubber type gasket 9 is provided to the signal recording surface of the disk 6 and then sealed up with a glass late 10 which is set oppositely to said signal recording surface and excels in the plane properties. Thus a cell 11 is obtained. Then a polymeric composition fluid 8 is injected to the cell 11 and cooled after the complete polymerization performed in a warm solution to obtain a polymer layer 8. This layer 8 is exfoliated from the disk 6 to obtain a polymer replica 13. Then a conductive film 14 of Au, etc. is coated to the signal recording surface of the replica 13 by a vapor deposition process, a sputtering process, etc. A metallic plating layer 15 is formed on the film 14 by a plating process. Then the layer 15 is exfoliated from the replica 13 to obtain a metallic master disk 16.
NAKAGAWA TOSHIHARU
YUASA FUMIHIKO
Next Patent: OPTICAL MAGNETIC RECORDING AND REPRODUCING DEVICE