A lead frame module includes a lead frame including ground conductors and signal conductors interleaved with the ground conductors side-by-side. The ground and signal conductors have transition portions extending between mating ends and terminating ends. A dielectric holder supports the lead frame and at least partially surrounds the transition portions of the ground and signal conductors. The dielectric holder has a first side and a second side with wells in the first side open to the transition portions of the ground conductors. A printed metal layer is formed in situ on the first side of the dielectric holder and at least partially fills the wells and engages the ground conductors in the wells to electrically connect to the ground conductors. The printed metal layer electrically connect a plurality of the ground conductors.