Some Comments on the Role of Electrodes in Dielectric Breakdown of Solids
Dielectric breakdown in solids may be broadly classified as “thermal” or “purely electrical”. In thermal breakdown one considers the joule energy input from the power source as being partly used in raising the temperature of the dielectric and partly conducted away. Breakdown occurs when the temperature gradient cannot provide adequate thermal conduction to remove the joule heat; the temperature of the dielectric (and consequently the current density) then rises in an uncontrolled way. The applied voltage at this point is the critical voltage, and for reasonable material parameters, the time interval to the occurrence of the instability is of the order of seconds or longer. In purely electrical breakdown the time interval for voltage collapse is of the order of microseconds or less. In modelling this phenomenon, one therefore proposes processes that feature electronic instability.
KeywordsElectrical Breakdown Breakdown Strength Dielectric Breakdown Outer Electrode Critical Voltage
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- J.J. O’Dwyer, The Theory of Electrical Conduction and Breakdown in Solid Dielectrics, Clarendon Press, Oxford, 1973.Google Scholar
- J.J. O’Dwyer, Proc. 2nd Int. Conf. Conduction and Breakdown in Solid Dielectrics (1986), in press.Google Scholar
- D.B. Watson, W. Heyes, K.C. Kao, and J.H. Calderwood, IEEE Trans. Elec. Insul. E1-1, 30 (1965).Google Scholar