Laser Bump Research Articles

Gradual laser zone texture for low flying height sliders

We measured the Acoustic Emission (AE) signals of the Head and Disk Interface (HDI) during slider seek operations using laser textured disks. We found that a gradual laser zone located outside the normal laser zone decreases the shock of landing in the CSS zone when the head flying height and laser bump height are comparable.

Experimental and theoretical studies of bump formation during laser texturing of Ni-P disk substrates

We provide here extended experimental data on the bump shape formed on Ni-P disk substrate under various laser and substrate surface conditions, and describe a model for the Sombrero-shape bump formation based on competition between thermocapillary and chemicapillary flows. This model rationalizes a large body of experimental data and provides insight into how one might tailor bump shapes to specific requirements. For comparison, laser bump formation on non-Ni-P substrates has also been studied.

Laser zone texture on alternative substrate disks

A sealed, compact, and low power CO/sub 2/ pulsed laser is used to melt a focused microscopic area on an alternative glass ceramic substrate. By precisely controlling the laser power, pulse duration, pulse rate, and the disk movement, a well-refined array of bumps can be produced on the alternative substrate. The laser bump formation on the alternative substrate shows a positive-extending volume without any negative-extending volume. TEM electron diffraction shows a phase change from polycrystalline to amorphous in the melted area. In addition to the stress release, the domed bump formation could be doe to the volume expansion of newly formed amorphous phase. The CSS test results show that the supersmooth glass ceramic disk stiction can be reduced by one order of magnitude by applying laser zone texture. The transition zone width between laser texture and data zones can also be made as small as a few milli-inches to increase the recording area.