The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 30, 1991
Filed:
Dec. 07, 1987
Masanori Nishiguchi, Kanagawa, JP;
Takeshi Sekiguchi, Kanagawa, JP;
Ikkei Miyoshi, Kanagawa, JP;
Kiyoshi Nishio, Osaka, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Asahi Diamond Industrial Co. Ltd., Tokyo, JP;
Nissei Industry Corporation, Toyonaka, JP;
Abstract
A surface grinding machine comprises a wheel head vertically movably supported; a cup-shaped diamond wheel supported by a rotatable wheel shaft at one end of the wheel head and having an abrasive grain layer of Young's modulus (10-15).times.10.sup.4 kgf/cm.sup.2 at the lower end of the wheel; a wheel shaft driving motor for rotating the cup-shaped diamond wheel supported by the wheel head; a servomotor for vertically moving the wheel head; a suitable number of chuck tables for fixing the surface of a III-V group compound semiconductor wafer on which elements have been fabricated; an index table for rotatably supporting the chuck tables; a chuck table driving motor for turning the chuck tables; a main shaft motor current analysis circuit for detecting the current value of the wheel shaft driving motor; a main shaft rotation number analysis circuit for detecting the number of rotations of the wheel shaft driving motor, and a feed speed control circuit for controlling the serevomotor in such a manner as to decrease the feed speed when the grinding resistance is greater than a predetermined resistance value, and increase the feed speed when the grinding resistance is smaller than the predetermined resistance value.