Noise Properties Of Thick-Film Conducting Lines For Integrated Inductors

Studies of noise properties of thick-film conducting lines from Au or PdAg conductive pastes on LTCC or alumina substrates are reported. Experiments have been carried out at the room temperature on samples prepared in the form of meanders by traditional screen-printing or laser-shaping technique. Due to a low resistance of the devices under test (DUTs), low-frequency noise spectra have been measured for the dc-biased samples arranged in a bridge configuration, transformer-coupled to a low-noise amplifier. The detailed analysis of noise sources in the signal path and its transfer function, including the transformer, has been carried out, and a procedure for measurement setup self-calibration has been described. The 1/f noise component originating from resistance fluctuations has been found to be dominant in all DUTs. The analysis of experimental data leads to the conclusion that noise is produced in the bends of meanders rather than in their straight segments. It occurs that noise of Au-based laser-shaped lines is significantly smaller than screen-printed ones. PdAg lines have been found more resistive but simultaneously less noisy than Au-based lines.