Method for manufacturing a multilayer printed circuit board and composite foil for use therein

摘要

A method for manufacturing a multilayer printed circuit board includes providing a core board, a composite foil including a carrier foil, a functional copper foil and a non-reinforced thermosetting resin layer, the functional copper foil being electro-deposited with a uniform thickness of more than 4 mum but less than 10 mum on the carrier foil, the functional copper foil having a front side facing the carrier foil and an opposite backside which is coated with the non-reinforced thermosetting resin layer. The method further involves laminating the composite foil with the non-reinforced thermosetting resin layer on the core board and removing the carrier foil from the functional copper foil in order to uncover the front side of the functional copper foil. A CO2 laser source drills holes from the uncovered front side of the functional copper foil through the functional copper foil and the non-reinforced thermosetting resin layer to form microvias.