New materials for hybrid circuits: Organometallic compounds

The results of an investigation of organometallic materials for high-density and low-cost hybrid interconnections are reported. Organometallic compounds are processed as classical screened thick films or by spinning and photoetching. Because of their nature, these compounds offer some important advantages over classical thick or thin films at the quality level (low resistivity for gold conductor lines, and gold thermocompression with bonding usable with only a 0.3- mu m-thick layer), over thick films at the cost level (the ink is about 30% less expensive, and the thickness line can be adjusted to the optimal value from 0.1 to 2- mu m), and over thin films because of the very low equipment investment. These compounds can be used in place of thin films for applications which are critical for thick films, such as microwave circuits above 20 GHz or high-interconnection density circuits.<>