Electrical breakdown mechanism in contaminated polyimide coating

In this paper, in order to advance the quality to withstand the high voltage requirement on the polyimide (PI) that is coated on silver-metalised low-emission glass with a slot-die method, the electrical breakdown strength was evaluated experimentally and theoretically on different thicknesses of PI coatings. With a similar direct voltage (DC) applied on the different thicknesses of the PI coatings, the thicker sample has less breakdown occurrence with a lower electric field. The defect areas in all samples lead to electrical breakdown in the lower applied voltage; it is illustrated and explained that the higher electric field was formed near the contamination area by simulating the electric-field patterns with a new two-dimensional finite-element analysis method.