Abstract: A transport medium for orderly, in-process transportation of assembled electrical devices during backend processing. A carrier tray is comprised of a plurality of carrier units held in coplanar relationship by a frame. Preferably the carrier units are polyethersulfone inserts latchable into a coordinate matrix of carrier unit holes defined by a metallic sheet. Each carrier unit carries one or more electrical devices in device seats which expose a top and a bottom of each device sufficiently to eliminate any necessity for removing the devices from the medium during all backend processing. Each carrier unit has a standardized perimeter but a core which is adapted to a particular device size and form, and there can be as many different carrier units as there are different device forms and sizes, but all carrier units fit into a standard carrier unit hole. The frames and carrier units are robotically manipulable.