Machine for handling semiconductor material

Claim 1

A MACHINE FOR HANDLING WAFERS OF SEMICONDUCTOR MATERIAL COMPRISING A FEED MEMBER FOR FEEDING EACH OF THE WAFERS TO A MEASURING POSITION IN WHICH THE WAFER IS STATIONARY, MEANS FOR RETRACTING THE FEED MEMBER FROM A POSITIONED WAFER DURING A MEASURING OPERATION, A MEASURING DEVICE, MEANS FOR LOWERING THE MEASURING DEVICE INTO CONTACT WITH THE UPPER SURFACE OF A WAFER IN THE MEASURING POSITION TO DETERMINE ITS THICKNESS, MEANS FOR PRODUCING AN ELECTRICAL OUTPUT FROM THE MEASURING DEVICE WHICH VARIES ACCORDING TO THE THICKNESS OF THE WAFER, MEANS FOR RAISING THE MEASURING DEVICE, MEANS FOR AGAIN MOVING THE FEED MEMBER INTO ENGAGEMENT WITH A WAFER AFTER IT HAS BEEN MEASURED IN ORDER TO MOVE THE WAFER FROM THE MEASURING POSITION TO A FURTHER POSITION WHERE IT CAN DROP DOWN A TUBE, SAID TUBE HAVING A PLURALITY OF PLUNGERS SLIDABLY EXTENDING ACROSS IT AND EACH OF SAID PLUNGERS HAVING AN APERTURE THERETHROUGH AND A DEFLECTOR PORTION, MEANS FOR MAINTAINING ALL OF THE PLUNGERS WITH THEIR APERTURES IN LINE WITH THE TUBE WHEN IN THE NONOPERATED POSITION AND MEANS FOR OPERATING A DIFFERENT ONE OF SAID PLUNGERS IN RESPONSE TO DIFFERENT OUTPUT SIGNALS FROM THE MEASURING DEVICE REPRESENTING DIFFERENT RANGES OF THICKNESS FOR THE WAFERS TO MOVE THE APPROPRIATE PLUNGER UPON MEASURING A WAFER THICKNESS WITHIN A GIVEN RANGE SO THAT ITS DEFLECTOR PORTION IS LOCATED IN THE TUBE AND DEFLECTS A MEASURED WAFER FALLING THEREON OUT THROUGH AN APERTURE IN THE TUBE INTO A CONTAINER ASSOCIATED WITH THAT PLUNGER.