Transfer apparatus for semiconductor wafers

An apparatus for automatically transferring wafers between first wafer container means and second wafer container means, said wafers being used in the manufacture of integrated circuits, each of said wafers having a center of gravity and an edge surface, said first container means having two opposite sides with a plurality of parallel slots for receiving said wafers by their edge surfaces and having an open bottom and an open top, said second container means having longitudinal support means with a plurality of parallel slots for receiving said wafers by their edge surfaces and having a closed bottom and an open top, comprising:

• (a) first transfer means for transferring said wafers to and from said first container means, said first transfer means entering said first container means through said open bottom of said first container means, said first transfer means having a plurality of parallel slots for receiving said wafers by their edge surfaces and contacting said wafers at points below their centers of gravity;
• (b) second transfer means for transferring said wafers to and from said second container means and for transferring said wafers to and from said first transfer means, comprising retainer means and movement means;
• (c) said retainer means for retaining said wafers in the same relative orientation with respect to one another when said wafers are removed from a container means, said retainer means having first and second retainer wall means for supporting said wafers, each of said first and second retainer wall means each having a lower edge and an inside surface, said first and second retainer wall means oriented relative to one another such that said inside surfaces face each other, each of said first and second retainer wall means inside surfaces having a plurality of parallel slots for receiving said wafers by their edge surfaces;
• (d) said first and second retainer wall means pivotable relative to one another between open and closed positions, said closed position being where said first and second retainer wall means contact said wafer edge surfaces at points located below the centers of gravity of said wafers, said open position being where said first and second retainer wall means are out of contact with said wafer edge surfaces and said retainer wall means can be inserted or removed from said second container means, said first and second retainer wall means pivotable between open and closed positions when said lower edges of said retainer wall means are inside of said second container means.