| 摘要 |
PURPOSE:To enable polishing powder and falling-off abrasive grains to be discharged through spaces among plural grindstones by providing directly or via a mounting plate the grindstones on a lapping platen while putting the apex parts of said grindstones in order so as to form projections at a prescribed interval. CONSTITUTION:The lapping platen 10 of a flat polishing device, is constructed such that column-shaped grindstones 9 are positioned in their apex part polishing surfaces on the same plane of mounting plate division pieces 8, planted mutually keeping a prescribed interval, and threaded for fixing into a lapping platen 7 by inserting screws 12 into screw holes 11 provided through the mounting division pieces 8. In this instance, each of the column-shaped grindstones 9 is constituted by a PVA series grindstone. The PVA grindstone is manufactured by blending abrasive grain fine powder such as silicon carbide, an aqueous polyvinyl alcohol solution, aldehydes being a cross linker, a catalyst such as mineral acids, kinds of starch each being a porosity forming agnet in a proper ratio, allowing them to react under prescribed conditions, and making acetal the polyviynl alcohol. And, the total area of the polishing surfaces 9 is set to 30-90% of the area of the platen 7. |
