METHOD OF FABRICATING A GLASS MAGNETIC HARD DRIVE DISK PLATTER USING FILAMENTATION BY BURST ULTRAFAST LASER PULSES

摘要

A non-ablative method and apparatus for making an economical glass hard disk (platter) for a computer hard disk drive (HDD) using a material machining technique involving filamentation by burst ultrafast laser pulses. Two related methods disclosed, differing only in whether the glass substrate the HDD platter is to be cut from has been coated with all the necessary material layers to function as a magnetic media in a computer's hard drive. Platter blanks are precisely cut using filamentation by burst ultrafast laser pulses such that the blank's edges need not be ground, the platter's geometric circularity need not be corrected and there is no need for further surface polishing. Thus the platters can be cut from raw glass or coated glass. As a result, this method reduces the product contamination, speeds up production, and realizes great reductions in the quantity of waste materials and lower production costs.

主权项

1. A method of producing glass hard disk drive platters from a magnetic media coated substrate, using laser machining, comprising the steps of:
providing a planar glass substrate with a layered system of magnetic media coatings, said planar glass substrate includes a top surface and a bottom surface; providing a laser beam comprising a burst of laser pulses; providing a laser beam delivery system capable of focusing said laser beam onto said top surface of said planar glass substrate and to enable relative movement between said laser beam and said planar glass substrate; focusing said laser beam relative to said top surface of said planar glass substrate to form a beam waist external to said top surface of said planar glass substrate, said laser pulses incident on said top surface of said planar glass substrate are focused such that sufficient energy density is maintained within said planar glass substrate to form a continuous laser filament therethrough without causing optical breakdown; laser ablating a portion of said magnetic media coatings on said top surface of said planar glass substrate; laser ablating a portion of said magnetic media coatings on said bottom surface of said planar glass substrate; creating a laser filament that cuts completely through said glass substrate by photoacoustic compression; enabling relative movement between said focused laser beam and said planar glass substrate moving said laser filament created in said planar glass substrate in circular geometric patterns relative to said glass substrate cutting circular platters from said planar glass substrate.