Back to results
US 2022/0068304 A1Published application
Dummy substrate and manufacturing method thereof
AssigneeShowa Denko K.K.
InventorsSunao Kakita, Takahiro Kushino, Hidenori Inada
Life of this patent
Estimating the term…
Abstract
A dummy substrate is formed with a disk-shaped glass substrate having a center hole, and a magnetic recording film on an outer circumferential surface along a thickness direction of the glass substrate and an inner circumferential surface of the center hole, and a surface roughness (Ra) of one surface and the other surface of the glass substrate is in a range of 0.2 nm or more and 100 nm or less.
Claims18
A dummy substrate, comprising:
- a disk-shaped glass substrate having a center hole;
- and
- a magnetic recording film formed on an outer circumferential surface along a thickness direction of the glass substrate and an inner circumferential surface of the center hole, wherein
- a surface roughness (Ra) of one surface and the other surface of the glass substrate is in a range of 0.2 nm or more and 100 nm or less.
1 more element
Dependencies are inferred from the claim text.