Thin Film media has been in production now for over 25 years. The process normally starts with an aluminum disk or glass substrate with a polished plated nickel layer. This layer is then textured (cleaned and cleaned again). Once entering the coating system, a series of sputtered layers are typical. Usually an underlayer is sputtered onto the surface to promote adhesion, but also to orient the magnetic layer which is to be deposited next. The magnetic layer or layers are optimized by controlling the alloy, the vacuum system’s atmosphere, the temperature, the substrate bias, and the underlayer thickness. Over the magnetic layer is a protective layer, normally carbon or some variation of carbon. The media is then removed from the deposition system and tested for magnetics and flyability.
Thin Film heads came into being in the early 80’s with IBM introducing the 3380 disk storage system. The head process is highly complicated with over 250 traveler steps including multi-sputtered layers, complex photolithography, and electroplating of some of the layers. Head technology has been rapidly changing to smaller devices, magnetoresistive (Mr), and today, Giant Magnetoresistive (GMR).