Hydrostatic high pressure studies of polymer thick-film resistors

The behaviour of carbon black/polyesterimide thick-film resistors under hig h hydrostatic pressure (up to 5000 bar) and at the temperature range from 2 0 to 150 degrees C is presented. The gradual resistance decrease observed w ith pressure increase is dependent on carbon black kind and contents. Much higher compressibility of polymer matrix than active phase affects gradual increase of carbon black volume fraction. The basic relationship of percola tion theory, rho proportional to(nu(CB)-nu(CB))(-t), is used successfully f or semi-quantitative analysis of high pressure effect on tested devices. It is shown that this effect is temperature independent. (C) 1998 Elsevier Sc ience Ltd. All rights reserved.