Process for forming copper coating having excellent mechanical properties, and printed-wiring board with conductor pattern formed of such copper coating
AssigneeBrother Kogyo Kabushiki Kaisha
InventorTakeshi Miyabayashi
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Abstract
A process of forming on a substrate a copper coating which has excellent mechanical properties, comprising depositing copper on the substrate by chemical plating, and forming at least one silver-rich layer during the deposition of copper, each silver-rich layer has a higher content of silver than the other portion of the copper coating. Also disclosed is a process of producing a printed-wiring board by forming such a copper coating.
Claims15
A process of forming on a substrate a copper coating which has excellent mechanical properties, comprising the steps of depositing copper on said substrate by chemical plating in a deposition bath by intermittently adding sodium iodide and a chelate compound of silver and ethylenediaminetetraacetic acid to said deposition bath, thereby forming at least one silver-rich layer during the deposition of copper.
A process of producing a printed-wiring board having an electrically insulating substrate, and a conductor pattern formed on said substrate, said conductor pattern consisting of a copper coating which is formed by depositing copper on selected areas of said substrate by chemical plating in a deposition bath such that said selected areas define said conductor pattern, said process comprising the step of forming at least one silver-rich layer during the deposition of copper by intermittently adding sodium iodide and a chelate compound of silver and ethylenediaminetetraacetic acid to said deposition bath.
A process of producing a printed-wiring board having an electrically insulating substrate, and a conductor pattern on at least one of opposite major surfaces of said substrate, said process comprising:
- forming a copper coating over an entire area of said at least one major surface, by depositing copper on said at least one surface by chemical plating in a deposition bath, said chemical plating performed by intermittently adding sodium iodide and a chelate compound of silver and ethylenediaminetetraacetic acid to said deposition bath;
- forming at least one silver-rich layer during the deposition of copper;
- and
- removing selected portions of said copper coating so that unremoved portions of the copper coating define said conductor pattern.
A printed-wiring board comprising an electrically insulating substrate, and at least one conductor pattern consisting of a copper coating which is formed by deposition of copper by chemical plating, said copper coating including at least one silver-rich layer, the concentration of silver being greatest closest to said substrate.
A process of forming on a substrate a copper coating which has excellent mechanical properties, comprising the steps of depositing copper on said substrate by chemical plating in a deposition bath by adding a reducible silver compound and a reducing agent to said bath, thereby forming at least one silver-rich layer during the deposition of copper.
A process of forming on a substrate a copper coating which has excellent mechanical properties, comprising the steps of depositing copper on said substrate by chemical plating in a deposition bath by adding a reducible silver compound and a reducing agent to said bath, thereby forming at least one silver-rich layer during the deposition of copper, the concentration of silver being greatest closest to said substrate.
Dependencies are inferred from the claim text.