Abstract: A substrate carrier device is disclosed which is used to mount and electrically connect a plurality of electrical substrates to a carrier substrate. The substrate carrier device includes a substrate tray having planar top and bottom surfaces. The top surface is adapted to have a plurality of electrical substrates mounted thereon. Substrate guide rails extend from the major perimeter edges of the bottom surface of the substrate tray and are adapted to be inserted and accepted within a pair of substrate guides, found on the carrier substrate. Electrical connection devices, mountable to the tray between each electrical substrate, engage associated electrical connectors on the carrier substrate. A flexible circuit interconnects each electrical connection device to an adjacent and associated electrical substrate, thereby providing an electrical path between an electrical substrate and the carrier substrate.