A microelectronic assembly includes an interconnection element, a conductive plane, a microelectronic device, a plurality of traces, and first and second bond elements. The interconnection element includes a dielectric element, a plurality of element contacts, and at least one reference contact thereon. The microelectronic device includes a front surface with device contacts exposed thereat. The conductive plane overlies a portion of the front surface of the microelectronic device. Traces overlying a surface of the conductive plane are insulated therefrom and electrically connected with the element contacts. The traces also have substantial portions spaced a first height above and extending at least generally parallel to the conductive plane, such that a desired impedance is achieved for the traces. First bond element electrically connects the at least one conductive plane with the at least one reference contact. Second bond elements electrically connect device contacts with the traces.