Characterization of disk vibrations on aluminum and alternate substrates

Author

McAllister, Jeffrey S.

Author_Institution

Disk Memory Div., Hewlett Packard Co., Boise, ID, USA

Volume

33

Issue

1

fYear

1997

fDate

1/1/1997 12:00:00 AM

Firstpage

968

Lastpage

973

Abstract

Aluminum disk platters in 3.5 inch disk drives have been shown to vibrate at their natural frequencies due to air flow excitation. This causes track misregistration that can limit the tracks per inch (TPI). This was shown to be a characteristic behavior of 95×0.8 mm aluminum disks. Measurement methods which are useful in characterizing disk vibrations are described. A laser doppler vibrometer, focused on the disk surface, is used as a velocity sensor to measure force hammer excited frequency response functions, spin-up waterfall plots, and constant speed power spectra. These measurement methods were used to characterize disk platter vibrations on aluminum and alternate substrates in 3.5 inch disk drives. Alternate substrates which have significantly higher stiffness to density ratios (specific stiffness), dramatically reduce the amplitude of these disk vibrations and may provide higher TPI capability

Keywords

aluminium; frequency response; hard discs; laser velocimetry; magnetic recording; substrates; vibration measurement; 0.8 mm; 3.5 in; 95 mm; Al; Al substrate; air flow excitation; constant speed power spectra; disk platters; disk vibrations; force hammer excited frequency response functions; hard disc drives; laser doppler vibrometer; specific stiffness; spin-up waterfall plots; stiffness to density ratios; track misregistration; tracks per inch capability; velocity sensor; Aluminum; Disk drives; Force measurement; Frequency; Laser excitation; Power lasers; Sensor phenomena and characterization; Surface emitting lasers; Vibration measurement; Vibrometers;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.560140

Filename

560140