Above motherboard interposer with quarter wavelength electrical paths

A multi-layer interposer substrate, comprising:

• multiple layers of single interposer substrates stacked to form the multi-layer interposer substrate, each single interposer substrate, comprising:
• a first array of interposer interconnects in the single interposer substrate, 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 in the single interposer substrate, 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 arranged to have 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;
• and
• an array of connections for a peripheral circuit on each single interposer connected to the at least one conductive trace.