The trays are mounted on a generally cylindrical carousel which is rotated about its axis to bring successive ones of the trays into {HEAD ~ position} for loading {TAIL ~ wafers} on to the trays and unloading wafers from the trays 
for loading
The trays are mounted on a generally cylindrical carousel which is rotated about its axis to bring successive ones of the trays into { HEAD ~ position } for loading { TAIL ~ wafers } on to the trays and unloading wafers from the trays
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH