Method for manufacturing printed circuit boards
AssigneeSiemens Aktiengesellschaft
InventorAntoon Mattelin
Life of this patent
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Abstract
A method for manufacturing printed circuit boards has a double etch process to form interconnection wiring. A metal layer is formed on the substrate. An etch resist layer is applied to the metal layer. The layer is selectively removed to allow for selective etching of the metal layer. A second etch resist layer is applied to the metal layer not previously etched. The side walls of the metal layer are also protected by the resist. The second etch resist layer is then selectively removed to allow for a second etching of the metal layer. After the second etching, the interconnection wiring remains in the desired pattern. The second etch resist layer, which may be tin, can be left on the wiring to improve component soldering.
Claims17
A method for manufacturing printed circuit boards, comprising the steps of:
- generating a metal layer on an insulating substrate;
- applying a first etch resist layer onto said metal layer;
- selectively removing said etch resist layer so as to expose a first undesired region of said metal layer;
- completely etching said first undesired region away leaving a second undesired region of said metal layer and a desired region of said metal layer;
- applying a second etch resist layer onto said second undesired region and said desired region of said metal layer;
- selectively removing said second etch resist layer from said second undesired region of said metal layer;
- anodically contacting said second undesired region of said metal layer;
- and
- completely electrolytically etching said second undesired region away so as to leave said desired region of said metal layer remaining.
Dependencies are inferred from the claim text.