Repozytorium publikacji - Politechnika Gdańska

The properties of polymer based thick film layers mede using different resistive pastes and dipping silvers have been studied. The composite of carbon and graphite (C/Gr) conducting particles suspended in different polymer vehicles were used for preparation resistive layers. Interface resistance Rc created between dipping silver (DiAg) contact layer and resistive layer was determined from the surface potential distribution measurements and its value was less than 1% of total sample resistance. The temperature dependence of conductivity was measured in the temperature range from 110 to 310 K. VA characteristic is linear in both electric field orientations. Minimum resistance value is at temperature 230 K. For low temperature range conductivity is thermally activated with activation energy about Ea = 15 meV. The new principle for non-destructive testing of conductivity solids based on the phonon interaction with conducting electrons has been applied. The ultrasonic signal change the contact area between conducting grains and then resistance is modulated by frequency of ultrasonic excitation. Resultant intermodulation voltage depends on the value of ac current varying with frequency fE and on the ultrasonic excited resistance change deltaR varying with frequency fU. The intermodulation component of frequency fm = fE - fU varies linearly with electric excitation and quadratic dependence on ultrasonic excitation was observed. The main task was to determine the influence of polymer thermal expansion and its wetability on the thick film conductivity.

Autorzy

• Vlasta Sedlakova,
• Josef Sikula,
• prof. zw. dr hab. inż. Ludwik Spiralski link otwiera się w nowej karcie