Patent ID: 7857121
Filing Date: 2010-12-28
Classification: H01L

Abstract:
1. A system for conveying and for accurately handling a generally flat object employing a plurality of support elements, the device comprising: a plurality of vacuum preload drive wheels arranged in one or more drive units, each drive unit comprising at least one vacuum preload drive wheel for applying a lateral drive force to the object; one or more counter plates adjacent to each of the vacuum preload drive wheels, each counter plate including one or more peripheral pressure ports connectable to a pressure source for exerting a repelling force on the object so as to prevent physical contact between the object and the system; and one or more vacuum ports located on said one or more counter plates for applying induced holding-down forces on the object, the vacuum ports of each drive unit being fluidically connected to a main vacuum pipe that is connectable via a controllable valve to a vacuum source; whereby when the main vacuum pipe is connected to the vacuum source the normal force between the object and the vacuum preload drive wheels is increased and accordingly the lateral drive force is increased.