Current status and future of magnetic heads for HDD

Abstract

The rapid growth in consumer electronics application requires higher capacity data storage. For hard disk drive (HDD), many new technologies, such as media, heads, head‐disk interface (HDI), pre‐amp. and so on, have been introduced in order to increase the recording density. This paper focus on magnetic head technologies, such as materials, structures, fabrication process and head performance for HDD. For read heads, tunneling magnetoresistive (TMR) heads have come successively to replace giant magnetoresistive (GMR) heads. Barrier materials have been studied to obtain higher magnetoresisance (MR) ratio with lower resistance area product (RA). AlOx have been used as barrier for 100–120 Gb/in2 TMR heads. MgO barrier shows significantly large MR ratio and is also workable to TMR heads as AlOx one. For longitudinal magnetic recording (LMR) writer, recording performance has been improved with reducing yoke length and coil turns and changing to pole materials with higher saturation magnetization (Bs). Perpendicular magnetic recording (PMR) is introduced for over 120 Gb/in2. Combination between head and medium is much more important in PMR than LMR. The magnetic head is still one of the key component of HDD and is expected to be going to further promote the redording density and performance of HDD in the future. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)