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:
Feb. 28, 1984
Filed:
Apr. 02, 1982
Kiyoo Katagiri, Niigata, JP;
Mitsuo Honda, Niigata, JP;
Shin-Etsu Engineering Co., Ltd., Tokyo, JP;
Naoetsu Electronics Co., Ltd., Niigata, JP;
Abstract
The present invention relates to an improvement in the lapping method of wafer-like work pieces in a lapping machine to lap the work pieces by sandwiching them between relatively rotatable upper and lower surface plates, in which the thickness of the work pieces under lapping is determined by an in-machine manner with a sensor mounted on the upper surface plate. Different from conventional lapping methods with an in-machine measurement of the thickness, the thickness of the work pieces is computed only once at regular intervals corresponding to one relative revolution of the surface plates so that the errors due to the operation per se of the lapping machine such as the undulated revolution of the surface plates, vibration of the machine and the like can be eliminated and very much improved control means for the thickness of the work pieces under lapping can be obtained.