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CD and DVD Replication

CD Replication is mostly a mechanical way of producing the disc. When you buy software, music or films from a shop this is the process they will have been made. This method is best used for runs over a 1000 pieces and can run in to the millions.

The Process- First off the data is burnt by a laser onto a glass plate that is coated with a photosensitive material, you will often hear the phrase ‘glass master’ this is the first stage in the process. Once the glass master is finished a metal stamper is developed via electrolysis from the plate, it physically has a track with pits in that eventually the laser in the player will read when the disc is done.

Once the stamper is made the glass plate is recycled for use in the making of different stampers. The stamper is then laid into an injection moulding machine and the image is physically pressed into molten optical grade polycarbonate disc under a pressure of about 30 tons. You could compare this to the way vinyl records are made but on a smaller disc. The disc then is taken out of the mould and allowed to cool in a controlled environment so that it does not deform. If you were to look at the disc now you would see a clear piece of plastic and you would just be able to make out the data that had been pressed into it. This is so along that if you were to rub your finger across the disc it would be completely destroyed. The next stage is to create a reflective layer that the laser in the player can use, this process is spluttering. The disc enters a vacuum chamber that has an aluminum plate at the top and a magnet at the bottom, a puff of argon gas is added and an electrical charge is applied this transforms the surface of the aluminum to atomize and a plasma is formed. This is then drawn down onto the disc buy the magnet. The disc exits the chamber and is coated with a UV varnish to protect the disc and stopping the aluminum from oxidizing. The disc is then ready to be printed and packaged. The lead-time in producing a disc this way is normally 10 to 12 working days.