THE INITIATION OF HIGH-CURRENT DENSITY SWITCHING IN ELECTRICALLY CONDUCTIVE POLYMER COMPOSITE-MATERIALS

In this paper, the idea that high power switching in conductor-filled polymer composite materials is triggered by the injection of a high en ergy density at the electrical contact interfaces is tested. A simple theoretical model for the electrical contact interface is developed an d used to predict that the time required for switch initiation should be inversely proportional to the square of the product of average init ial current and contact resistance. This scaling prediction is tested by means of switching experiments where the switch initiation time is monitored as a function of average initial current level and contact r esistance. It is found that the experimental data are consistent with the theory over a variation of more than three orders of magnitude in both initial current level and contact resistance. In addition, it is determined that the data are consistent with the interpretation that p olymer ablation is the physical event which triggers switching. (C) 19 98 American Institute of Physics.