Possibilities for Air Fireable Base Metal Conductors

Abstract

This paper discusses the status of thick conductive films formed by firing in air. The metals under study include nickel, chromium, aluminum and copper. The properties of the films are presented for firing temperatures ranging from 580 to 850 degrees C. Compatibility with various dielectrics and glasses have been studied. Multilayer wiring seems promising. Potential uses on porcelain enamelled steel, window glass and alumina substrates seem feasible.Initial studies have been made of compatibility with thick film ruthenium-based resistors. Some preliminary information on termination resistance and other properties observed in such combinations is presented.Possible applications in gas discharge displays for cathodes and conductor runs are discussed. Potential uses may include economical ground planes, solar cell electrodes, varistor and thermistor terminations, and resistance thermometers.

Effect of firing atmosphere on air-fireable glass-free electrically conductive thick film

“…10,13 Thick-film conductors with base metals such as Ni, Cr, Al, and Cu and fired in air suffer from inadequate bonding. 15 Passivating components are usually used in developing air-fireable thick-film conductor inks with base metals such as Ni, Cr, Al, and Cu. [15][16][17][18] A boron compound, which tends to be reduced during the pyrolysis of the organic vehicle, is used in a nickelbased thick-film conductor in order to make the paste fireable in air.…”

“…15 Passivating components are usually used in developing air-fireable thick-film conductor inks with base metals such as Ni, Cr, Al, and Cu. [15][16][17][18] A boron compound, which tends to be reduced during the pyrolysis of the organic vehicle, is used in a nickelbased thick-film conductor in order to make the paste fireable in air. 17 In the case that the firing atmosphere is oxidizing, elemental boron is used in the paste, so that it is oxidized and serves as a glass that protects the nickel particle from oxidation after vehicle removal.…”