Method of producing a totally shielded signal line

Abstract From the Canadian patent

Process for Fabricating a Fully Shielded Signal Line, Coaxial signal lines of rectangular cross-section are fabricated for use in integrated high- and ultra-high-frequency circuits, thereby eliminating crosstalk. A photolithographic film not only assists in the formations of metallic conductive areas, but also remains between those conductive areas as the dielectric material between inner and outer conductors of a fully shielded rectangular coaxial cable. The coaxial cable is formed in a process which comprises various photoprocessing electrodeposition, chemical deposition and chemical etching steps, but which avoids mechanical surfacing to remove insulating material from adjacent portions …