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. 07, 2020
Filed:
Jan. 31, 2017
Helmut Fischer Gmbh Institut Fur Elektronik Und Messtechnik, Sindelfingen, DE;
Werner Volz, Sindelfingen, DE;
Paul Boos, Bodelshausen, DE;
Helmut Fischer GmbH Institut für Elektronik und Messtechnik, Sindelfingen, DE;
Abstract
A vacuum chuck for clamping workpieces, in particular wafers, and a measuring device and a method for checking workpieces by way of X-ray fluorescent radiation. The vacuum chuck has a clamping plate having a support surface, having at least one suction connection arranged on a base body for connecting to a negative-pressure device and for clamping the workpiece on the clamping plate by negative pressure received by the base body and having several suction grooves arranged in the clamping plate and are open towards the support surface. The support surface has concentric suction grooves having a suction opening to which a negative-pressure line is connected or which is connected to a work channel. Each suction groove having a separate negative pressure, which is separate to the adjacent suction groove, is selectively controlled by a control valve by a control for supplying the respective negative pressure in the respective suction groove.