Master disk having grooves of different depths for magnetic printing and manufacturing method therefor
View Patent ↗A master disk has an aspect ratio of a width of a groove to a depth thereof to facilitate embedding of a soft magnetic film in the groove for stabilizing magnetic printability. The master disk has at least two differently shaped grooves, in each of which the width of the groove is equal to the width in the sector direction of a servo pattern and the depth is varied. A servo pattern has a width equal to a width of the groove in the sector direction, with the depth of the groove being proportional to the servo pattern width. At least two depths of grooves are provided for embedding magnetic materials on a substrate of the master disk. The depth of the groove for embedding the soft magnetic film is made shallow in a region where the pattern width of the servo pattern is narrow and made deep in a region where the pattern width is wide.
1. A master disk for magnetic printing, the master disk forming a magnetic pattern in a magnetic recording medium by the magnetic printing, the magnetic disk including
a substrate having grooves, the grooves including grooves of different depths; and
magnetic materials embedded on a substrate in the grooves of different depths.
2. A method of manufacturing the master disk of claim 1 , including forming the groove by repetitive photolithography.
3. The master disk for magnetic printing as claimed in claim 1 , wherein the depths of the grooves for embedding the magnetic material is proportional to a pattern width in a sector direction of a servo pattern.
4. The master disk for magnetic printing as claimed in claim 3 , wherein the depth of the grooves for embedding the magnetic material varies stepwise with respect to the pattern width of the servo pattern.
5. A method of manufacturing the master disk of claim 3 , including forming the grooves by repetitive photolithography.
6. A method of manufacturing the master disk of claim 4 , including forming the grooves by repetitive photolithography.
7. The master disk for magnetic printing as claimed in claim 3 , wherein the grooves for embedding the magnetic material have a first region where the pattern width of the servo pattern is narrow and a second region where the pattern width is wide, wherein the grooves are shallow in the first region, and deep in the second region.
8. The master disk for magnetic printing as claimed in claim 7 , wherein the depth of the grooves for embedding the magnetic material varies stepwise with respect to the pattern width of the servo pattern.
9. A method of manufacturing the master disk of claim 8 , including forming the grooves by repetitive photolithography.
10. A method of manufacturing the master disk of claim 7 , including forming the grooves by repetitive photolithography.