Patent ID: 8099190
Filing Date: 2012-01-17
Classification: H01L,Y10S

Abstract:
1. Apparatus for transferring a substantially flat and substantially circular object, such as a wafer, from a pick-up position to a delivery position, the apparatus comprising: a manipulator; at least one light source for emitting a source signal, said source signal being a confined beam of light; at least one light sensor for sensing said source signal and for providing a sensor signal in response thereto; and a computing device arranged for processing at least one sensor signal to obtain data on the position of said object; the manipulator being arranged for simultaneously transferring a first and a second object along a path, said objects being substantially flat, substantially equally sized, and substantially circular, each object having a main surface and a central axis extending perpendicular to the main surface through the center of the object, the objects being carried by the manipulator in a substantially parallel orientation, spaced apart from each other, and substantially co-axially whereby the central axis of each object may be displaced radially; and wherein a first virtual line connects the at least one source to a first sensor, and wherein a second virtual line connects the at least one source to a second sensor, the at least one source and the first and second sensors being positioned such that, both the first and the second object intersect the first and second virtual lines during a transfer of said objects along said path, whereby the virtual lines include an angle with respect to the central axes of the first and second objects.