Browse Prior Art Database

Reclaiming Blanks and Diamonds from Saw Blades

IP.com Disclosure Number: IPCOM000082712D
Original Publication Date: 1975-Jan-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 23K

Publishing Venue

IBM

Related People

Barclay, DJ: AUTHOR [+2]

Abstract

Diamond saws such as those used for dicing semiconductor wafers can consist of 0.002 inch thick 4 inch diameter stainless steel discs or blanks. The circumferences of the blanks are coated with an abrasive composite nickel-diamond layer.

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Reclaiming Blanks and Diamonds from Saw Blades

Diamond saws such as those used for dicing semiconductor wafers can consist of 0.002 inch thick 4 inch diameter stainless steel discs or blanks. The circumferences of the blanks are coated with an abrasive composite nickel- diamond layer.

The apparatus schematically illustrated, shows how blanks and diamonds can be reclaimed when the cutting edge becomes worn and requires replating. Stainless steel blank 1 with its diamond-nickel edge 2 is immersed in an acid solution 3 containing a sulphur compound. Thus solution 3 may consist of 5% sulphuric acid containing sulphur dioxide added as 0.1gm/litre of sodium metabisulphite. Also within solution 3 is a luggan capilliary 4 from a saturated calomel electrode 5 and counter electrode 7. Potentiostat 6 is connected between blank 1, electrode 5 and counter electrode 7, so that the potential of the blade 1 can be varied with respect to the electrode 5.

By maintaining the potential of stainless steel blank 1 between -300 and +200 millivolts (typically +100 mv) with respect to saturated calomel electrode 5, nickel in layer 2 is dissolved but there is no etching of the stainless steel. Diamonds are reclaimed from the electrolyte by sedimentation or centrifuging. Nickel can also be stripped from brass or from copper if they are maintained at -90 mv or - 70 mv, respectively, with respect to the saturated calomel electrode 5. The use of the sulphur compound accelerates the etching of...