Preparation and Performance of Copper Conductive Slurry for Single-Layer Capacitor Applications

Copper conductive slurries were prepared using Cu powder as conductive phase, specially prepared SiO 2 -Na 2 O-CaO-MgO-K 2 O glass powder as adhesive phase, and terpineol as vehicle, in addition to some other organic gradients. The resultant Cu conductive slurry was screen-printed onto both sides of a Pb(ZrTi)O 3 substrate, followed by degreasing and sintering, to obtain a single-layer capacitor consisting of a Pb(ZrTi)O 3 substrate and double-sided Cu conductive films. The influence of the glass powder content in the slurry and the sintering temperature on the porosity, sheet resistivity, and adhesion strength of the resultant films was investigated. The capacitance and dielectric properties of the single-layer capacitors prepared in this work were compared with those of two commercial single-layer capacitors. The results show that Cu conductive films prepared using 10.0 wt.% glass powder and sintered at 900°C achieve optimal properties overall, with low sheet resistivity of 3.2 mΩ/sq and high adhesion strength of 12.5 MPa to the Pb(ZrTi)O 3 substrate. Furthermore, the capacitor prepared from the Cu conductive slurry developed in this work has high capacitance of 435 pF and low dielectric loss of 0.021, which are far superior to those of the capacitors prepared using two commercial conductive slurries. The present results show that the Cu conductive slurries obtained in this work have great potential for use in ceramic capacitors.