Temperature Dependence of the Resistance of Adhesive Conductive Joins and Thermal Expansion of Conductive Adhesives

The temperature dependence of the resistance of adhesive conductive joints and the thermal coefficient of longitudinal expansion of conductive adhesives are parameters that can significantly affect the properties of this type of conductive joining. The dependence of these parameters on temperature was investigated. Adhesive mounting zero-value resistors to the test PCB prepared adhesion joints. The adhesive was applied by stencil printing. The resistance of the joints was measured by the four-point method and the thermal expansion of used adhesives was measured by the thermomechanical analysis technique. The junction resistance was found to increase approximately linearly with temperature, but the joints were found to harden when measured. It was also found that the coefficient of thermal longitudinal expansion varies depending on the adhesive and also on the sample when all samples are made from the same adhesive. The reason is the not completely reproducible adhesive application technology for this measurement.