Servo pattern formation via transfer of sol-gel layer and magnetic media obtained thereby
View Patent ↗A method of manufacturing a magnetic recording medium including a servo pattern, comprising steps of: (a) providing a non-magnetic substrate including at least one major surface; (b) providing a stamper having a surface with a plurality of recesses forming a negative image of a servo pattern; (c) forming a layer of a partially dried sol-gel material having a first surface in conformal contact with the recess-patterned surface of the stamper and an exposed second surface opposite the first surface; (d) urging the major surface of the substrate into contact with the exposed second surface of the sol-gel layer; (e) removing the stamper from contact with the layer of sol-gel material to expose the recess-patterned surface thereof; (f) converting the partially dried sol-gel layer to a glass-like layer while preserving the recess pattern in the surface thereof; and (f) forming on the recess-patterned surface a laminate of layers constituting a servo-patterned magnetic recording medium.
1. A structure for use in the manufacture of a patterned thin film magnetic recording medium, comprising:
a non-magnetic substrate including at least one major surface; and
a layer of a glass or glass-like material on said major surface of said substrate, said layer of glass or glass-like material including an exposed surface having a pattern of recesses formed therein by a process comprising steps of:
(a) providing a non-magnetic substrate having a major surface;
(b) providing a stamper having a recess-patterned surface comprising a negative image of said pattern of recesses to be formed in said medium;
(c) forming a layer of a spin-coated, partially dried sol-gel material on said recess-patterned surface of said stamper, said layer comprising a micro-porous structure of silica (SiO 2 ) particles with solvents saturated in the micro-pores thereof, said layer having a first surface in conformal contact with said recess-patterned surface of said stamper and an exposed second surface opposite said first surface;
(d) urging said major surface of said substrate into contact with said exposed second surface of said layer of partially dried sol-gel material;
(e) removing said recess-patterned surface of said stamper from contact with said first surface of said layer of partially dried sol-gel material while leaving said second surface of said layer of partially dried sol-gel material in contact with said major surface of said substrate, whereby said layer of partially dried sol-gel material is transferred to said major surface of said substrate, such that said first surface of said layer of partially dried sol-gel material is exposed and includes a positive image of said pattern of recesses; and
(f) converting said layer of partially dried sol-gel material to a glass or glass-like layer while preserving said pattern of recesses in said exposed first surface thereof.
2. The structure as in claim 1 , wherein said non-magnetic substrate comprises a disk-shaped, high modulus substrate having a pair of major surfaces and is comprised of a glass, ceramic, or glass-ceramic material.
3. The structure as in claim 1 , wherein said pattern of recesses in said exposed surface of said glass or glass-like layer forms a servo pattern for said magnetic recording medium.
4. The structure as in claim 3 , wherein said recesses are from about 1 to about 500 nm deep, from about 0.001 to about 1 μm wide, and adjacent recesses are spaced apart at least about 0.001 μm.
5. A servo-patterned magnetic recording medium, comprising the structure as in claim 4 and a laminate of thin film layers formed thereover, said laminate including seed, underlayer, magnetic recording, protective overcoat, and lubricant topcoat layers sequentially formed over said exposed first surface of said glass or glass-like layer including said positive image of said servo pattern formed therein.