Hardware Reference
In-Depth Information
Figure 11.1. CD manufacturing process.
The steps in manufacturing CDs are as follows (use
Figure 11.1
as a visual):
1.
Photoresist coating
—A circular 240mm diameter piece of polished glass 6mm thick is spin-
coated with a photoresist layer about 150 microns thick and then hardened by baking at 80°C
(176°F) for 30 minutes.
2.
Laser recording
—A Laser Beam Recorder (LBR) fires pulses of blue/violet laser light to
expose and soften portions of the photoresist layer on the glass master.
3.
Master development
—A sodium hydroxide solution is spun over the exposed glass master,
which then dissolves the areas exposed to the laser, thus etching pits in the photoresist.
4.
Electroforming
—The developed master is then coated with a layer of nickel alloy through a
