Compact disc manufacturing is the process by which commercial compact discs (CDs) are replicated in mass quantities using a master version created from a source recording. This may be either in audio form (CD-Audio) or data form (CD-ROM). This process is used in the mastering of CDs, and does not include CD-Rs or DVDs, although these are made using similar methods.
A compact disc (CD) can be used to store audio, video, and data in various formats which are defined in the Rainbow Books. A CD is usually manufactured in a class 100 or better clean room, and can usually be manufactured with strict manufacturing tolerances for only a few US cents.
CD mastering differs from burning, as the pits and lands of a mastered CD are moulded into the CD, rather than being 'burn marks' (phase changes) by a CD burner.
All CDs are pressed from a digital source, with the most common sources being low error-rate CD-Rs or files from an attached computer hard drive containing the finished product. Some CD pressing systems can use digital master tapes, either Digital Audio Tapes, Exabytes or Umatics.
mastering is performed in a class 100 or better clean room or a self-enclosed clean environmnent within the mastering system. If introduced during critical stages of manufacturing, contaminants such as dust, pollen, hair and smoke can render the master unusable. Once completed, a CD will resist effects caused by these contaminants.
After mastering, the glass master is baked to harden the developed surface material and it is ready for metalisation. Metalisation is a critical step prior to the electrogalvanic manufacture (electroplating).
Electroforming occurs in "Matrix", the adopted name for the electroforming process area and is still a class 100 cleanroom. The information contained on the metalised glass master is extremely fragile and must be transferred to a more resilient form for use in the injection moulding equipment.
CD moulding machines are specifically designed high temperature polycarbonate injection moulders. They have an average throughput of 550-900 discs per hour, per moulding line.
For quality control, both the stamper and the moulded discs are tested before a production run.