A die feed (Also known as a die sorter or pick and place machine) is an electromechanical test handler that presents a unit to a test site in order to allow the unit to be tested. It is sometimes referred to as pick and place because the handlers pick the units for testing from a tray and presents them at the test site so that testing may occur. Once testing is complete, the system takes the unit and places it into the appropriate output tray. It allows the quality of the die to be confirmed once the wafer has been separated.

Pick and place is typically used in assembly. Before reaching the machine, solder pads are established on the circuit board, usually made of tin-lead, silver, or copper. The solder paste is applied to all of the solder pads with a stainless steel stencil. Then the boards proceed to the pick-and-place machines, thus placed on a conveyor belt. SMDs are typically delivered to the production line via paper of plastic tapes after being wound on reels. Silicon chips or integrated circuits are then usually delivered stacked up in static-free plastic tubes, or sometimes trays. The pick-and-place machines then remove these parts from the reels or tubes, whichever is used, and place them on a PCB.

Using die sorters has many different advantages over different techniques such as wafer probing. Die sorters are not only able to screen out electrical failures but are also capable of screening for damaged die during the demounting process before packaging. They are also capable of sorting die into bins so that what need be processed for current orders can be done and save time.

Die feed systems make it easy to retest die, allowing room for error should a test not work correctly. There is also no ink involved in this process which not only takes care of the messiness that comes with ink but also takes away the time that it takes to cure wet ink, making the process faster.