New Application of Electrically Conductive Adhesive as a Transistor-based Electrical Circuit under AC and DC Currents

Document Type : Original Article


1 Department of Materials Science and Engineering, Hamedan University of Technology, Hamedan, Iran

2 Department of Electrical Engineering, Hamedan University of Technology, Hamedan, Iran

3 Department of Materials Science and Engineering, University of Bonab, Bonab, Iran


Electrically conductive composite adhesives containing 70, 75 and 85 wt% of filler particles (Cu@Ag) and polymer matrix were prepared. Thermal stability and morphology of the prepared adhesives were examined using TG (Thermo-Gravimetry), DSC (Differential Scanning Calorimetry), and Scanning Electron Microscope(SEM) techniques. In the next step, a transistor-based electrical circuit using self-biased common-emitter combination was made from the prepared conductive adhesive as well as a copper board. All of the prepared boards were subjected to DC (8-30 V) and AC (1 kHz) currents to evaluate their performance. For these circuits, parameters such as transistor operating points and the voltage gain of the amplifier, were measured. TG and DSC analyses showed that increasing the filler amount from 70 to 85 wt%, reduces the weight loss of the adhesive from 15.48 to 11.35 wt%. Also, effect of increasing the silver amount in Cu@Ag particles on the thermal stability of adhesives at temperatures below 350 °C showed that by increasing of the amount of silver from 20 to 40 wt%, has a negligible effect on weight change (about 2 wt% at 250 °C). Both samples showed almost the same overall weight loss at 350 °C. Evaluation of circuit performance showed that the changes in circuit width (1, 1.5, and 2 mm) has no significant effect on the V–I characteristics and voltage gain. The value of these two parameters for all three circuits and also the copper board circuit were the same which indicates the high conductivity of the prepared conductive adhesive.


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