First introduced in 1979 on the IBM 3370 disk drive, thin-film technology used photolithographic techniques similar to those used on semiconductor devices to fabricate HDD heads with smaller size and greater precision than ferrite-based designs then in use. Thin layers of magnetic (Ni–Fe), insulating, and copper coil wiring materials are built on ceramic substrates that are then physically separated into individual read/write heads integrated with their air bearing significantly reducing the manufacturing cost per unit.[3] Thin film heads were much smaller than MIG heads and therefore allowed smaller recorded features to be used.