Laser induced nanobump array on magnetic glass disk for low flying height application

Abstract

Laser processing has found an important application in the hard disk drive (HDD) industry to fabricate bumps for screen testing of the manufactured magnetic disk media prior to HDD assembly. The flying height of the head slider needs to be calibrated by a specifically designed bump array. With areal density of HDD already exceeds 100Gbits/in2, the head slider flies at 6 nm flying height and will become even lower. Sub-10nm bump height, as low as 3.5nm, is required to match future slider flying height. In this study, bump arrays with sub- 10nm bump height, good height uniformity and precise distribution was fabricated on glass disk substrate using an integrative control system consisting of a pulsed CO2 laser and a high precision stage. The bump disk requirements were demonstrated successfully and compared with industrial specifications. © 2007 IOP Publishing Ltd.