Creating a CD

The manufacture of a conventional silver CD is a fairly long and complicated process that needs different materials and machinery. A template must first be made by etching the pattern of data into a photoresist material using a high power laser. A layer of metal such as silver is evaporated over the photoresist and the metal layer built up by electrolysis. This creates a stamp called the “father” but it is not used directly to make the prints. It is duplicated by making 3-6 inverted copies called “mothers” which are in turn used to make “sons” for use as stampers. The stampers are used in an injection molding process to produce polycarbonate discs. A reflective metal such as aluminium or silver is used as a coating to fill in the pattern on the polycarbonate and finally a label is silk screened on the top. This would be a very expensive way of making single copies of a disc and is only cost effective for use in mass production.

A different technique for creating a medium that can selectively reflect a laser back to a sensor must be used for producing a single disc.