The invention relates to thick film conductor compositions which are useful in application to both via-fill and/or line conductors to manufacture of Low Temperature Co-fireable Ceramic (LTCC) devices and other Multilayer Interconnect (MLI) ceramic composite circuits such as Photosensitive Tape On Substrates (PTOS); gold, silver and mixed metal multilayer circuits and devices. The invention is useful for forming microwave and other high frequency circuit components selected from the group comprising: antenna, filters, baluns, beam former, I/O's, couplers, via feedthroughs, EM coupled feedthroughs, wirebond connection, and transmission lines.