Patents by Inventor Nenad Mandich

Nenad Mandich has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5512201
    Abstract: A metal dissolving liquid and method for stripping tin and solder coatings, including the underlying tin-copper alloy, from the copper substrate of a printed circuit board. The liquid includes an aqueous solution of nitric acid in an amount sufficient to dissolve solder and tin, a source of ferric ions in an amount sufficient to dissolve tin-copper alloy, a source of halide ions in an amount sufficient to solubilize tin, an effective amount of methylsulfonic acid as promoter for complete stripping, and a source of an organic, water soluble amine. The combination of ingredients will substantially eliminate sludge formation, reduce attack on the copper substrate and provide a bright copper finish after solder removal. A liquid further including organic triazoles including benzotriazole in amounts not more than about 5% by weight and sulfamic ions in amounts not more than about 2.5% by weight.
    Type: Grant
    Filed: February 13, 1995
    Date of Patent: April 30, 1996
    Assignee: Applied Chemical Technologies, Inc.
    Inventors: Rajwant Singh, Nenad Mandich, Gerald A. Krulik