THIN FILM INTERFACE FOR PASSIVATION AND BONDING
Original Publication Date: 1983-Apr-30
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
Two problems exist with prior art optical disks: (a) oxidation of the media and (b) disk radial runout. Thin films of SiO eliminate both prohems. or A1203 depositied over tellurium, the writing medium, will
1EROX DISCLOSURE JOURNAL
THIN FILM INTERFACE FOR PASSIVATION AND BONDING U.S. C1. 365/126 Roberta M. Fay
Int. CI. G1 lc 11/46
Richard D. Weir
Two problems exist with prior art optical disks: (a) oxidation of the media and (b) disk radial runout.
Thin films of SiO eliminate both prohems. or A1203 depositied over tellurium, the writing medium, will
Oxidation of tellurium occurs in the presence of water vapor and oxygen and adversely affects the writing and reading process. Therefore, a protective barrier layer is needed to prevent the oxidation. SiO and A1 03 have been used in semiconductors. The thin films have demonstraTed long Term stability in these devices. The two materials are glass formers in bulk and readily develop glassy phases in thin films. Hence, the Si02 and A1 O3 will both protect the tellurium and enhance the adhesive bonding of the disk to &e backer plate.
Adhesive bonding of the disk to the backer plate will automatically reinforce the disk. Present day disks have a severe radial runout problem caused by drooping of the super thin glass substrate. "Drooping" refers to surface deformation of the disk caused by radial deflection of gravitation exerting a downward force at various points along the radial axis of the disk. Sometimes more than 30 minutes is required to adjust the amount of sagittal displacement of the focus actuator and other times adequate adjustments cannot be made. Bonding the droopy glass to a thick backer...