PROPERTIES OF CONDUCTIVE FILMS MADE FROM FINE SPHERICAL SILVER PALLADIUM ALLOY PARTICLES

Silver-palladium alloy films were made by a thick-film technique using several metal powders prepared by the spray-pyrolysis method. Two types of powders were used: silver-palladium alloy powders (15 mol% Pd and 30 mol% Pd) and mixtures of silver and palladium powders. The fired films were about 2-3-mu-m in thickness. The alloy particles sintered uniformly in firing, whereas, in the case of the powder mixtures, the alloying of silver and palladium particles caused uneven particle growth and large voids were formed in the fired films. For this reason the films made from the alloy powders had better conductive properties than those made from the powder mixtures. The resistivities of the films made from the alloy powders were close to the intrinsic value for silver-palladium alloys. Further, the oxidation of palladium during heating in air was significantly suppressed in the alloy powders when the palladium content was lower than 30 mol% in accordance with thermodynamic considerations.