An interposer assembly for forming electrical connections between contact pads on opposed substrates includes a top plate, a bottom plate, a lateral shift interface between the plates and a plurality of electrical circuit paths extending between contact surfaces at the top of the top plate and at the bottom of the bottom plate. The circuit paths maintain electrical connections between opposed pairs of pads on the substrates despite misalignment of the substrates or lateral shifting of the plates at the interface because of forces exerted on the substrates. The plates are secured together to permit limited lateral movement at the interface. The assembly may have a circuit board plate between the top and bottom plates and two lateral shift interfaces. The contacts may have very small and high contact pressure shear-formed contact tips.