A method of and an apparatus for electrically interconnecting two integrated circuits devices includes mounting the two devices face to face. A first device is mounted for example to a substrate or lead frame. The first device includes a plurality of electrical/physical mounting structures preferably positioned along one edge. The mounting structure provide both electrical interconnection and physical mounting. A second device includes a corresponding plurality of mounting structures configured as a mirror image of the mounting structures on the first device. The mounting structures on the second device are also positioned along one of its edges so that once the mounting structures are brought together in a face to face relationship, the second device cantilevers off the edge of the first device. Under certain circumstances, a dummy block can be mounted to the substrate adjacent to the first device to act as a strut or support for the second device. The mounting structures can be positioned sufficiently close to one another that surface area consumed for I/O is minimized. Another set of electrical interconnect structures can be formed on the surface of the second device on the edge opposite the mounting structures. Electrical connection can be formed to these electrical interconnect structures using conventional techniques such as tape automated bonding.