Editing Disk read-and-write head (section)

===Thin-film heads===
First introduced in 1979 on the [[IBM 3370]] disk drive, [[thin film|thin-film technology]] uses photolithographic techniques similar to those used on semiconductor devices to fabricate hard drive heads.  At the time, these heads had smaller size and greater precision than the ferrite-based heads then in use; they were electronically similar to them and used the same physics. Thin layers of magnetic (Ni–Fe), insulating, and copper coil wiring materials were built on ceramic substrates that were then physically separated into individual read/write heads integrated with their air bearing, significantly reducing the manufacturing cost per unit.<ref>{{cite web  |url=https://www.computerhistory.org/storageengine/thin-film-heads-introduced-for-large-disks/ |title=1979: Thin-film heads introduced for large disks  |date=December 2, 2015 |website=Computer History Museum |access-date= June 19, 2019}}</ref> Thin-film heads were much smaller than MIG heads and therefore allowed smaller recorded features to be used. Thin-film heads allowed 3.5&nbsp;inch drives to reach 4&nbsp;GB storage capacities in 1995. The [[geometry]] of the head gap was a compromise between what worked best for reading and what worked best for writing.<ref name=":0" />