Specify which layers need 9 ozThe copper-only sums differ by 0.560 mm. These are arithmetic examples, not complete stackups or manufacturing capability claims.Specify which layers need 9 ozFour heavy layers and two heavy layers are different constructions.ALL FOUR HEAVYMIXED COPPER315 / 315 / 315 / 315 µm315 / 35 / 35 / 315 µmCopper sum: 1.260 mmCopper sum: 0.700 mmLayer roles, symmetry and insulation decide the actual stackup.³Ô¹Ïtv engineering illustration · conceptual, not to scale · examples are not acceptance limits