A peep into how Compact Discs are manufactured

Ever wonder how a CD aka Compact disc is manufactured? There is a whole string of tasks involved in creating the compact disc. It starts by creating an original master disc made of glass. During the process, the glass disc is treated with two chemicals - a primer and a photo resistant coating. Then the photo resistant coating on the glass surface is dried in an oven for 30 minutes. Then the data that goes on the CD is etched on the glass and then the glass is electrocoated by applying a thin coating of nickel and vanadium. After going through a few other steps, what you have is a die - or a master copy. The CDs that you hold in your hand are manufactured from this master copy. The CDs are not made of glass but is actually a liquid polycarbonate which is injected into the mold to create the CDs.

One thing worth noting is that there are two different ways of creating a CD. One is the recordable CDs or blank CDs and the other is the pressed CD in which the data is directly stamped on the disc at the time of creation of the disc. An example of pressed CDs are the ones you get along with a IT magazines.

I found this short video of manufacturing a CD quite informative. The video clip details the creation of a pressed CD.

Update (Feb 14th 2007): The Youtube video clip embedded here has been removed as I have been notified by its real owners that the video clip is copyrighted.