Methods and apparatus for retaining a tray stack having a plurality of trays for carrying microelectric devices

A machine for processing microelectronic devices, comprising:

• a stack of trays, each tray carrying a plurality of microelectronic devices;
• a receiving station having a platform with a tray singulator and a mounting element, the tray singulator being configured to selectively separate and retain a single tray from the stack of trays;
• a portable tray retainer configured to hold the stack of trays, the tray retainer being releasably attached to the receiving station and the tray retainer including a casing and a plurality of retaining elements, wherein the casing includes a guide structure with a first end spaced apart from the receiving station and a second end proximate to the receiving station, a cross-member extending across at least a portion of the guide structure proximate to at least the first end, and an opening proximate to at least the second end through which the trays can pass into or out of the casing, wherein the retaining elements are positioned proximate to the opening and are moveable between a storage position and a load/unload position, the retaining elements projecting into the guide structure in the storage position to hold the trays in the retainer, and at least a portion of the retaining elements projecting away from the guide structure and engaging a corresponding mounting element of the receiving station in the load/unload position to allow the trays to pass through the opening and to releasably hold the retainer to the receiving station, and wherein the cross-member is moveably positioned in the casing to move along a load/unload path to push a bottom tray of the tray stack against the retaining elements when the retaining elements are in the storage position and to drive the bottom tray out of the casing to the singulator when the retaining elements are in the load/unload position;
• and
• a processing station that processes microelectronic devices on trays that have been unloaded from the retainer.