Characterization of Direct Patterned Ag Circuits for RF Application

We investigated the effects of sintering temperature on microstructural evolution and electrical characteristics of screen printed Ag patterns. A commercial conducting paste containing Ag nanoparticles was screen printed onto a Si substrate passivated with SiO2 and sintered under a sintering temperature range from 150°C to 300°C. Four point probe method was used to measure the DC resistance, while a network analyzer and Cascade’s probe system in the frequency range from 10MHz to 30GHz were employed to measure the S-parameters of the sintered Ag conducting patterns. The resistivity under the application of a DC decreased from 398μΩcm to 9μΩcm with increasing sintering temperature from 150°C to 300°C. From the measured S-parameters, the electrical losses in high frequencies also decreased with increasing sintering temperature (about 1.2dB at 30GHz) due to the formation of an interparticle neck after heat treatment at high temperatures.