Although many people do not immediately recognize it as a form of data storage, the CD, or compact disc, represents one of the most universal needs for ion beam etching. Many are so accustomed to just popping a CD into the nearest audio or video player and enjoying the end result that they do not put much thought into the technology that has made their entertainment possible. In order to understand how the ion beam process words for this kind of application, it is important to know how CDs are made.
It looks like a single flat disc that spins inside of a player, but it is actually made of three layers. The first layer is made of polycarbonate plastic. Manufacturers and engineers use these plastics because they offer a range of benefits. They can resist both hot and cold temperature extremes, withstand and resist unusual impact and be used for a wide variety of end-user applications, including research and engineering and over-the-counter consumer purposes. The flexibility of this kind of material places it in high demand.
On top of the plastic layer, CDs have a thin layer of aluminum coating. Some manufacturers choose to use silver or gold instead of the aluminum. The etching process, which resembles sandblasting, is often used during the making of this layer. Atoms from an ion beam are used to sputter a thin layer of the aluminum onto the plastic. This process is considered extremely productive in high-volume environments. Adding this layer by hand for millions of CDs could be time-consuming. After the aluminum layer is done, another protective acrylic layer goes on to finish the CD. Companies that make CDs also have to make sure that they are sticking to universal standards to keep them compatible for many uses. For example, one of the rules is making sure the environment is clean and free of dust.
Ion beam sputtering has been used for other purposes, as well. It is used to selectively expose parts of a layer in when making semiconductors. A pattern is made on the surface of this layer to make it function properly. During design phases for some products, it is used to ready layers of material for microscopic inspection. This ensures products are verified before being released and can pass any type of fail analysis. Some research has also used ion beams to predict golfers’ performance using artificial grass.
By the time a CD or any other product that is subjected to ion beams reaches the market, it has undergone many processes. Consumers get to enjoy the product without giving much thought to these processes. It is always helpful, though, to know how things become what they eventually are to an end-user.