Patent ID: 9066431
Filing Date: 2015-06-23
Classification: H05K,Y10T

Abstract:
1. A method for manufacturing a printed circuit board with a patterned electrically conductive layer visible, comprising: providing a copper clad laminate comprising a light-pervious insulation layer and a copper foil, the copper foil comprising a copper layer and a first black oxidation layer formed on one side of the copper layer, the copper foil having a first surface on the first black oxidation layer, and an opposite second surface on the copper layer, the first surface of the copper foil being adjacent to the light-pervious insulation layer; etching the copper foil to convert the copper foil into a first patterned electrically conductive layer, the first patterned electrically conductive layer comprising a plurality of first openings to expose parts of the light-pervious insulation layer, thus the copper foil defining a plurality of inner surfaces interconnecting the first and second surfaces in the first openings, thereby obtaining a preformed circuit board; blackening the inner surfaces and the second surface of the first patterned electrically conductive layer to form a second patterned electrically conductive layer comprising the first black oxidation layer, a second black oxidation layer and the copper layer encapsulated in the first and second black oxidation layers; wherein a method for blackening the inner surfaces and the second surfaces of the first patterned electrically conductive layer comprises: cleaning the second surface and the inner surfaces of the first electrically conductive layer; micro-etching the second surface and the inner surfaces to roughen the second surface and the inner surfaces; and black oxidation treatment of the second surface and the inner surfaces to blacken the second surface and the inner surfaces, thereby obtaining the second patterned electrically conductive layer; and laminating a light-pervious overlay onto the second patterned electrically conductive layer, thereby obtaining a printed circuit board with the second patterned electrically conductive layer visible.