Abstract: Thermal shock tolerance is achieved in conductive core printed wire circuit boards, especially those having graphite or copper-Invar-copper cores for heat removal and expansion control, by filling the oversized through-holes with glass-filled, m-diallyl phthalate resin and plating on the inner surface of a bore drilled through the resin. Meta-diallyl phthalate has a coefficient of thermal expansion that is lower than epoxy and that is closer to that of the core. It creates a substantially void free, dielectric collar between the plating and the core to insulate the two electrically. Its use temperature is higher than epoxy while its curing temperature is lower than polyimide. The boards can be made by molding of the thermosetting resin in a peel ply process that avoids milling of the board and reduces waste.