Abstract: This invention relates to three dimensional packaging of integrated circuit chips into stacks to form cuboid structures. Between adjacent chips in the stack, there is disposed an electrical interconnection means which is a first substrate having a plurality of conductors one end of which is electrically connected to chip contact locations and the other end of which extends to one side of the chip stack to form a plurality of pin-like electrical interconnection assemblies. The pin-like structures can be formed from projections of the first substrate having an electrical conductor on at least one side thereof extending from this side. Alternatively, the pin-like structures can be formed from conductors which cantilever from both sides of an edge of the first substrate and within which corresponding conductors from both sides are aligned and spaced apart by the first substrate thickness. The spaces contain solder and form solder loaded pin-like structures.