초록 ▼

Circuit boards, useful in microwave frequency applications, are formed from a laminate consisting initially of an insulator sandwiched between a copper foil and an aluminum plate. The boards are provided with through-hole connections by means of a procedure which includes drilling through the board

Circuit boards, useful in microwave frequency applications, are formed from a laminate consisting initially of an insulator sandwiched between a copper foil and an aluminum plate. The boards are provided with through-hole connections by means of a procedure which includes drilling through the board to form through-holes, anodizing all exposed surfaces of the aluminum, electroplating copper over all anodized aluminum surfaces, sodium or plasma etching to alter the surface of the walls of the holes in the insulator to allow them to be “wet”, and electroless copper plating the entire board to form a continuous upper coating over the copper foil, the copper plate and the walls of the through-holes.

대표청구항 ▼

A circuit board structure comprising: a laminate of dielectric material sandwiched between a first relatively thick layer of aluminum and a second relatively thin layer of copper; at least one through-hole in the laminate; a coating of conductive metal electroplated on all outer or exposed surfaces

A circuit board structure comprising: a laminate of dielectric material sandwiched between a first relatively thick layer of aluminum and a second relatively thin layer of copper; at least one through-hole in the laminate; a coating of conductive metal electroplated on all outer or exposed surfaces of said aluminum, said outer or exposed surfaces of said aluminum being anodized prior to electrodeposition of the conductive metal; and a coating of conductive electroless deposited metal on all outer or exposed surfaces of the relatively thin copper layer, the electroplated aluminum and the dielectric material, including any portions thereof defining the walls of the through-holes. The circuit board of claim 9 wherein the step of forming through-holes further comprise: forming a pattern of holes through the aluminum-dielectric-copper laminate whereby the subsequent steps of anodizing, electroplating, etching and electroless plating will establish conductive paths through the board via plated through-holes.