On the design of coplanar waveguide bond wires as transmission lines

A packaging structure has been proposed such that coplanar bond wires may be maintained at a constant height above the device substrate and so function as a transmission line. The characteristic impedance of such a “coplanar wire waveguide” transmission line has been determined as a function of its wire spacing and height above the substrate. The large sensitivity to height above the substrate is shown, thus requiring great precision in maintaining that height in a practical arrangement