Experimental Analysis on Electrical Breakdown of Acrylic VHB Tape under Quasi-Static and Pulsed Voltage

Resumo

The dependence of electrical breakdown on the rate of change of voltage between the electrodes is investigated for VHB4905, a very common polyacrylate adhesive tape produced by 3M with interesting dielectric properties. If voltage is applied according to a quasi.static loading protocol, it is found that the dielectric strength of the tape VHB4905 can increase from 35 to 70 kV/mm, depending on the uniaxial prestretch applied in the considered range: 0.500%. In the case of a voltage pulse, the dielectric strength depends on voltage intensity at the leading edge of the pulse. In particular, for the considered duration of the leading edge of the voltage pulse (~20 ns), a breakdown strength threshold (minimum breakdown voltage) has been found, being 3.7 times larger than the breakdown strength measured under quasi.static loading conditions.