1. Glass Mastering:     Polycarbonate layer that contains the pits is made by a process called glass mastering.  A glass layer is covered with a layer of photo resist.	Image courtesy of www.disctronics.co.uk
This photo resist layer is "burnt" or exposed with a laser light.  This laser is known as the Laser Beam Recorder (LBR) and exposes only the areas where the final pits are to be placed.  The disc is spun at the exact linear velocity so that a correct track pitch can be maintained.  If an error occurs during this step, the controller will stop recording.	Image courtesy of www.disctronics.co.uk
Image courtesy of www.disctronics.co.uk	Photo resist will be developed and the laser exposed surfaces removed to make the pits.  The pit areas should go all the way through to the glass. The glass substrate and the photo resist are then covered with a layer of nickel alloy to make a negative image called the father. Photo resist can be cleaned off the glass so that the glass can be reused to make another CD.
2. Electroforming:  The father image is used as a stamper to make the polycarbonate layer of the CD.  Fathers can be used to make "mothers"  which are replicate image of the glass and photo resist.
3. Finishing Steps:  After the polycarbonate layer with the pits is made, it is covered with a thin layer of aluminum for reflection of the laser.  This layer is then coated with a protective lacquer and then the label is printed on-top.  The CD is then sent through quality control checks to make sure everything works correctly.	Image courtesy of www.disctronics.co.uk

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Last edited on May 14, 2000