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US 5,474,798 AGranted
Method for the manufacture of printed circuit boards
AssigneeMacDermid, Incorporated
InventorsGary B. Larson, Donna Kologe, Cynthia Retallick, Jon Bengston
Life of this patent
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Abstract
The present invention relates to a process for the manufacture of printed circuit boards. The method contemplates the use of electroless nickel as the primary medium for interconnection, for building circuitry to the desired thickness and as an etch resist. The method is particularly versatile in reducing the number of steps and variety of chemicals currently necessary to produce these circuit boards.
Claims13
A process for producing a printed circuit board, which process comprises the steps of:
- (a) Forming holes in a substrate which has copper cladding on both exterior surfaces;
- (b) Activating the holes to initiate and accept plating thereon;
- (c) Forming an image with a plating mask upon the exterior surfaces of the substrate, yielding masked surfaces and unmasked surfaces;
- (d) Cleaning the unmasked surfaces;
- thereafter
- (e) Plating the unmasked surfaces and the surfaces of the holes with an electroless nickel-boron deposit;
- thereafter
- (f) Plating electroless nickel-phosphorous deposits onto the nickel-boron deposits;
- thereafter
- (g) Stripping the plating mask to reveal exposed copper surfaces;
- and thereafter
- (h) etching to remove the exposed copper surfaces;
- wherein said process occurs substantially without copper plating.
10 more elements
A process for producing a printed circuit board, which process comprises the steps of:
- (a) Forming holes in a substrate which has copper cladding on both exterior surfaces;
- (b) Activating the holes to initiate and accept plating thereon;
- (c) Forming an image with a plating mask upon the exterior surfaces of the substrate, yielding masked surfaces and unmasked surfaces;
- (d) Cleaning the unmasked surfaces;
- thereafter
- (e) Plating the unmasked surfaces and the surfaces of the holes with an electroless nickel-boron deposit;
- thereafter
- (f) Plating electroless nickel-phosphorous deposits onto the nickel-boron deposits;
- thereafter
- (g) Stripping the plating mask to reveal exposed copper surfaces;
- and thereafter
- (h) etching to remove the exposed copper surfaces;
- wherein said process occurs substantially without electrolytic copper plating.
10 more elements
Dependencies are inferred from the claim text.