Low-frequency noise of polymer thick-film resistors: analysis of volume and contact effects

In the paper noisy properties of polymer carbon black thick film resistors are studied. It is shown that the noise measured on resistor terminations comes mainly from the bulk of the resistor. Contact noise is less then 8% of the bulk noise. The bulk resistor noise shows typical current noise properties. It has 1/f type power spectrum, its magnitude increases linearly with the square of biasing voltage and is proportional to the reciprocal volume of the resistor.