Preparation and Performance of Thick Copper Electronic Conductive Film from Copper Powders with Dual Particle Shapes
摘要
Copper electronic conductive slurries (CECSs) were prepared using Cu powder mixtures by blending Cu powders with spherical and polyhedral particle shapes as the conductive phase, mixed organic compounds as the solvent, and glass oxides as the adhesive phase. The CECSs were coated onto the surfaces of Al2O3 ceramic substrates by screen printing, then degreasing and sintering to obtain thick copper electronic conductive films. The effects of the ratio of Cu powders with spherical to polyhedral particle shape in the Cu mixtures on the microstructure and performances, including the sheet resistivity, adhesion force, and oxidation resistance of the resultant copper conductive films were investigated, and compared with those of copper conductive films prepared from Cu powders with single particle shape. The results showed that when the Cu conductive film was prepared from the Cu powders with single spherical particle shape, the sheet resistivity of the Cu film is 5.5 mΩ/cm2. By adding polyhedral particles in the Cu powders, the sheet resistivity of the Cu films can decrease to 3.0 mΩ/cm2 (spherical:polyhedral = 8:2). After being exposed to air for 120 days, the sheet resistivity of the Cu film prepared from the Cu powders with dual particle shapes (spherical:polyhedral = 8:2) increases only by 2%. The conductivity and oxidation resistance of the Cu film exhibit significant improvement by using Cu powders with dual particle shapes in the conductive films.