Production process of CD/DVD/BLU-RAYs using pressing method
During this process, the digital source material is verified and converted to a suitable format for CD/DVD/BLU-RAY replication (which includes production of the stamper).
The premaster (source material) is usually called the master. The complete premaster i.e. the master is delivered to the factory by the customer. The master may be on a physical carrier or it can be delivered as an image file.
The testing determines whether the premaster supplied by the customer meets the technical requirements and does not contain digital recording errors.
The master is checked by using a special tester (Eclipse), which compares the premaster’s compliance with the technical requirements of the format. This ensures that the copies, which are replicated from the premaster, are later working correctly in disc players.
- Mastering, i.e. production of the stamper (die)
To produce an industrial optical disc, first a stamper (die) is produced which acts as the negative of the information contained on the disc.
We are using the glass master technology:
- A 240 mm diameter and 6 mm thick glass plate is covered with a special light-resistant layer (photoresist).
• Premaster information is saved on the glass plate with a laser.
• The glass master is covered with a layer of nickel while in vacuum. This results in a so-called “father plate”, i.e., a positive.
• From this “father disc”, a “mother disc” is produced which is the negative of the production disc. This disc is used on the pressing production line to produce optical discs.
- Disc pressing
Industrial optical record discs are produced by injection molding. A stamper (die) is placed in the mould on the pressing production line. Polycarbonate, which is liquefied under pressure at 360 degrees, is injected into the enclosed mould, which in turn takes the form of the die in the mould. The mould is then cooled down and a transparent disc with recorded data is obtained.
To prevent the laser beam passing through the disc and to ensure the readability of information, one side of the disc is covered with aluminium. In the case of a CD, this means just one disc. A DVD consists of two thin discs.
- Applying lacquer and glue
To protect the information on the CD, the disc is covered with UV-lacquer, which is automatically cured on the production line.
In the case of a DVD, a special UV-glue is used to glue 2 thin discs together. The information is trapped between two discs and additional protection is therefore not necessary.
- Optical testing
Both the CD/DVD and the BLU-RAY production lines include a fully automatic tester which checks the mirror surface quality of the discs and separates low quality discs.
- Additional verification of the functionality and the quality of recording
Before the print is applied on the discs, the functionality of the production discs is tested by “running” them in a corresponding player. At least 1-2 discs are picked from each produced project to test the quality of the recording again, using the Datarius tester.
We print the design on the optic disc by using either screen printing or offset printing, depending on the customer’s order.
The optical disc is packed into the package chosen and ordered by the customer and laminated if necessary. When required, we can produce a sleeve and sticker for the product to be especially eye-catching. The final product is packed into cardboard boxes.