HDI-15 ELECTRIC FIELD ASSISTED DIP COATING PROCESS OF ULTRA-THIN PFPE LUBRICANT FILM FOR MAGNETIC DISKS(Head/Disk Interface and Tribology IV,Technical Program of Oral Presentations)

Abstract

The influence of the electric field on the dip-coating process was studied by using lubricants Z-tetraol, D-4OH, TA-30, and QA-40. The electric field assisted the adsorption of the lubricant molecules on the disk surface. This electric field also resulted in an increase in the lubricant film thickness. The surface free energy, step height, and head-disk clearance of the Z-tetraol lubricant film were not affected by the electric field; however, those of the other lubricant film were improved by the electric field. As the these results, we estimated that the molecular conformation of the lubricant changed from a random coil shape to a loose shape by the field, and the OH end-group functions aligned themselves along the direction of the field. These results show the possibility of reducing the head flying height by the EFAD coating process.