Influence of the Substrate on the Electrical Properties ofThick-Film Resistors

The effect of substrate type on the electrical properties of thick film resistors is determined. Five different substrates are used. The following properties are investigated: – thermal expansion, resistor profiles, resistance, TCR and resistor gauge factor. The resistors are physically inspected using X-ray diffractometry and electron probe analysis. This paper shows that conduction mechanism models for thick-film resistors generally need not take into account chemical and structural interactions with the substrate. However the effect of substrate on TCR values is significant for resistors exhibiting a large piezoresistive effect.