Abstract: A thin, flexible microelectronic assembly using thinned die (5-10 microns and lower) produced by growing a 1 ?m-10 ?m silicon epitaxial (Epi) layer on an oxidized silicon carrier. The integrated circuit process takes place in the standard manner in the Epi layer. The oxide layer and the silicon carrier serve as the backside handle. Once processed, the wafer can be bumped and singulated just like a normal chip without the need for the extra handle attachment processes or the backside thinning operation. Once the integrated circuits are flipped and solder reflowed to a substrate, the handle can be removed by etching the oxide. In one assembly embodiment, wells are etched in the flexible circuit board material to allow the interconnect to be recessed below the circuit board surface. An adhesive can then be placed on the board surface, locking the die to the flexible substrate. Alternatively, a nanowire interposer can be sandwiched between a bumped multilayer substrate and a bumped thin die.