Our simple model of the noise of a thick-film resistor leads to two limiting cases. For thick-film resistors with a
conduction dominated by the glass interface, the relative noise is proportional to the sheet resistance, R□. For thick
film resistors, where the conduction is mainly dominated by the current constrictions in the contact areas between
grains, the relative noise is proportional to R□3. Both trends have been observed. Some criteria of low-noise thick-film
resistors are derived from the developed noise relations.The major conclusion is that measurements of the noise index are a nondestructive way to check quantitatively
the operations used to manufacture high-quality thick-film resistors. Inadequate materials or treatments, weak or
brittle wire bonds and reliability are easily detected by 1/f noise measurements.
