A flexible circuit substrate has an integrated circuit mounted on the substrate, a first set of traces arranged to connect between a first voltage source and a first set of connectors on the integrated circuit, a second set of traces arranged to connect between a second voltage source and a second set of connectors on the integrated circuit, and a gap in the flexible circuit substrate between the first and second set of traces, the gap of sufficient width to stop an electrical arc-tracking between the first set of traces and the second set of traces. The substrate may have a second gap between the first gap and other traces.