ABOVE MOTHERBOARD INTERPOSER WITH QUARTER WAVELENGTH ELECTRICAL PATHS

A multi-layer interposer substrate includes multiple layers of single interposer substrates. Each single interposer substrate has a first array of interposer interconnects, each interposer interconnect in the first array of interposer interconnects corresponding to interconnects in an array of processor interconnects, a second array of interposer interconnects, each interposer interconnect in the second array of the interposer interconnects corresponding to an array of circuit interconnects on a circuit substrate, and at least one conductive trace in the interposer substrate in connection with at least one interconnect in the first array of interposer interconnects. The conductive trace has a parallel portion parallel to the interposer substrate such that no electrical connection exists between the interconnect and a corresponding one of the interposer interconnects in the second array of interposer interconnects. An array of connections for a peripheral circuit on each single interposer is connected to the at least one conductive trace.