Electroless plating of nickel onto surfaces such as copper or fused tungston
AssigneeMacDermid, Incorporated
InventorJon E. Bengston
Life of this patent
Estimating the term…
Abstract
Conductive surfaces such as copper and/or tungsten surfaces, particularly copper circuitry areas of printed circuit board substrates or fused tungsten circuitry areas of fused tungsten-ceramic packages, are activated for receipt of electroless nickel plating thereon by providing the surfaces with particulate zinc metal, particularly by contact of the surfaces with an aqueous suspension of particulate zinc metal.
Claims18
A process for selectively providing an electroless plating comprised of nickel over a conductive surface area of a substrate containing both a conductive surface area and a non-conductive surface area, said process consisting essentially of:
- (a) providing a substrate containing both a conductive surface area and non-conductive surface area;
- (b) non-selectively contacting said conductive surface area and said non-conductive surface area of said substrate with a composition comprising particulate zinc metal suspended in a carrier liquid, whereby said particulate zinc metal is thereby caused to be present on said conductive surface area and said non-conductive surface area of said substrate;
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- (c) non-selectively contacting said conductive surface area and said non-conductive surface area of said substrate, having said particulate zinc metal thereon, with an electroless nickel plating bath, whereby electroless deposition of a plating comprised of nickel selectively occurs over said conductive surface area of said substrate and not over said non-conductive area of said substrate.
A process for selectively providing an electroless plating comprised of nickel over a conductive surface area of a substrate containing both a conductive surface area and a non-conductive surface area, said process consisting essentially of:
- (a) providing a substrate containing both a conductive surface area and a non-conductive surface area;
- (b) immersing said substrate in a composition comprising particulate zinc metal suspended in a carrier liquid, whereby said particulate zinc metal is thereby caused to be present on said conductive surface area and said non-conductive surface area of said substrate;
- and
- (c) immersing said substrate, having said particulate zinc metal on said conductive surface area and said non-conductive surface area thereof, in an electroless nickel plating bath, whereby electroless deposition of a plating comprised of nickel occurs over said conductive surface area of said substrate and not over said non-conductive surface area of said substrate.
A process for selectively providing an electroless plating comprised of nickel over conductive surface areas, selected from the group consisting of copper and tungsten, which are present on a substrate also containing non-conductive surface areas, said process consisting essentially of:
- (a) providing a substrate containing both non-conductive surface areas and conductive surface areas selected from the group consisting of copper and tungsten;
- (b) non-selectively contacting said non-conductive surface areas and said conductive surface areas of copper or tungsten, with a composition comprising particulate zinc material suspended in a carrier liquid, whereby said particulate zinc metal is thereby caused to be present on said non-conductive surface areas and said conductive surface areas of copper or tungsten;
- and
- (c) non-selectively contacting said non-conductive surface areas and said conductive surface areas of copper or tungsten, having said particulate zinc thereon, with an electroless nickel plating bath, whereby electroless deposition of a plating comprised of nickel selectively occurs on said copper or tungsten surfaces of said substrate and not on said non-conductive surfaces of said substrate.
Dependencies are inferred from the claim text.