Apparatus for transferring semiconductor wafers
OwnerLester R. Johnsoninventor
Life of this patent
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Abstract
Semiconductor wafers are transferred from and to holder elements or "boats", in which the wafers are processed, by transfer apparatus including a movable head having rotatable holder elements which hold the wafers. Wafers are moved out of and into the boats by vertically moving lifting elements. The lifting elements move the wafers from a boat to the rotatable holder elements, and vertical lifting elements move the wafers from the rotatable holder elements into boats after the head has moved itself from one position to another. Typically, there are three positions or stations for the head, and vertical lifting elements are positioned at each station for moving the wafers vertically to and from the boats which are located at each station.
Claims16
Wafer transfer apparatus, comprising, in combination:
- table means for providing support and having a first station and a second station;
- head means movable on the table means from the first station to the second station;
- means for moving the head means on the table means;
- first lifting means at the first station for raising wafers to be transferred, including a first plurality of wafers and a second plurality of wafers;
- second lifting means at the second station for receiving transferred wafers and for lowering the transferred wafers;
- and
- roller means secured to the head means, including a first roller and a second roller, each of which includes a plurality of slots, and the first and second rollers are rotatable to a plurality of positions, including
- a first position in which the spacing between the slots of the first and second rollers is sufficient to allow the wafers to move between the rollers as the wafers are lifted by the first lifting means,
- a second position in which the rollers receive and hold the wafers lifted by the first lifting means for transporting the wafers from the first station to the second station, and
- a third position in which spacing between some of the slots of the first and second rollers is sufficient to allow the second plurality of wafers held by the rollers to move downwardly to be received by the second lifting means while the spacing between the remaining slots is sufficient to continue holding the first plurality of wafers by the rollers.
Dependencies are inferred from the claim text.