Electrical conduction of anisotropic conductive adhesives: effect of size distribution of conducting filler particles

The force-resistance relationship is investigated by considering for the fi rst time the effect of size distribution of metallic filler particles in an isotropic conductive adhesives. It is shown, for both the elastic and plast ic interactions between the metallic particle and the conducting plate, tha t the relationships between the applied force (F) and the resistance can be described as power-laws (i.e. proportional to F-n). The universal power-la w relationships are found to be independent of both the mean particle size and the standard deviation of the particle size distribution. However, the exponent constant n is much larger for a non-monosized filler particle dist ribution than that for a monosized one. Although the power-law relationship s are independent of the standard deviation of the particle size distributi on and the mean particle size, a large standard deviation of particle size distribution leads to a large resistance, The theoretical prediction of the power-law relationship is found to be supported by available experimental observations. (C) 1999 Elsevier Science Ltd. All rights reserved.