| 摘要 |
PURPOSE:To make a suction plate into such one that is no interposition of dust as well as holds down the manufacturing cost, by contributing it with removable materials by means of chemical erosion, electric discharge machining or the like and at least two types of unremoval materials, and forming it into the suction plate removed the said removable material on its outer surface part. CONSTITUTION:A suction plate 10 is attached to the top of a suction hole evacuated from a vacuum intake 10. This suction plate 10 is made up of sintering ceramics and metal, for example, copper. Afterward, this copper or materials 12 removable by means of chemical erosion, electric discharge machining or the like is removed, whereby ceramics or unremovable materials 14 are left behind as in projection form on an outer surface part of the suction plate 10. A sucked member 16 is attracted by vacuum suction from a clearance between porous materials and fixed to the suction plate by suction force. The outer surface part of the suction plate is of projection form, whereby a contact area between the sucked member 16 and the suction plate 10 is reduced and, what is more, elimination of dust is easy, so that occurrence of irregularities on grinding and polishing surface is checked, and highly accurate measurement is performable. |
