Conduction Processes in Thick Film Resistors. Part I

The structures of three families of thick film resistors have been investigated by scanning electron microscopy and electron probe micro-analysis. The two principal components of the resistive glazes, that is the conducting pigment and the glassy binder, have been identified in each case. The pigments were found to be simple or ternary oxides of the Pt transition metal group and Pd/PdO/Ag alloys. The glassy binders were based on lead borosilicate glasses. A model for the electronic conduction processes through the glass and pigments is proposed on the basis of the observed physical structures, the measured electrical properties of resistors and the properties of the component resistor materials. Part I of the total paper is concerned with identifying the phases in various Thick Film Resistors and part II considers the conduction processes that are appropriate.