Method for fabricating a fully shielded signal line

摘要

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 of the conductive walls of the outer conductor of the coaxial cable.