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Machining Process for Recording Disk Substrates

IP.com Disclosure Number: IPCOM000047728D
Original Publication Date: 1983-Dec-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Henneberg, MM: AUTHOR

Abstract

Today's method of substrate production for magnetic recording disks uses a vacuum chuck to clamp the substrate while a polished diamond tool is dragged vertically across the substrate blank. This produces a substrate of high dimensional, geometrical, and surface finish quality. Some processes follow up with a polishing operation. Other methods also use a combination of machining on a vacuum chuck, plus polishing sequences. Disadvantages of these methods are: 1. Placing a substrate against a vacuum chuck is labor-intensive, yet difficult to automate. 2. Some diamond-turning requires four total cuts, two on each side, i.e., the substrate is flipped and placed three times against the vacuum chuck over and above the initial and final handling. 3.

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Machining Process for Recording Disk Substrates

Today's method of substrate production for magnetic recording disks uses a vacuum chuck to clamp the substrate while a polished diamond tool is dragged vertically across the substrate blank. This produces a substrate of high dimensional, geometrical, and surface finish quality. Some processes follow up with a polishing operation.

Other methods also use a combination of machining on a vacuum chuck, plus polishing sequences. Disadvantages of these methods are: 1. Placing a substrate against a vacuum chuck is labor-intensive, yet difficult to automate. 2. Some diamond-turning requires four total cuts, two on each side, i.e., the substrate is flipped

and placed three times against the vacuum chuck over and

above the initial and final handling. 3. Diamond tools are expensive and their set-up is time-consuming. 4. Working against a vacuum chuck introduces defects

(axial acceleration) due to particle entrapment

between the chuck and substrate. This necessitates a clean

room environment and extensive process testing. 5. Diamond-turning and polishing machines cannot be synchronized; thus, the process flow is

interrupted. The method proposed here produces a substrate by a sequence of double-sided abrasive machining processes. The raw substrate blank is fed automatically or semiautomatically between a double-disk grinder. The wheels of the grinder are made of polyurethane foam loaded with SiC or other suitable abrasive. Their ...