P95 and P25 name two parts of a rigid polyimide buildP95 and P25 name two parts of a rigid polyimide buildCopper foilP25 prepreg: bonding layerCopper on P95 coreP95: cured glass-reinforced polyimideCopper on P95 coreP25 prepreg: bonding layerCopper foilEngineering illustration · Not measured production evidence · Not to scale