Abstract: A filter-dryer apparatus employing a single container for both filtering and drying operations including a container holding a material to be filtered and dried, adapted to connect to a filter system and to connect to a fluid bed dryer system, and a process for separating particulates from liquids by the operations of filtration and drying, which includes the steps of providing a single container for both filtering and drying operations; introducing a mixture of particles and liquid to said container; connecting the container to a filter system and filtering the particulates from the liquid; detaching the container from the filter system; connecting the container to a fluid bed drying system and removing the liquid from the particulates to result in dry particulates.
Type:
Grant
Filed:
September 13, 2007
Date of Patent:
May 11, 2010
Assignee:
Applied Chemical Technology, Inc.
Inventors:
John Patrick Banister, Robert R. Garner, Jr.
Abstract: This invention relates to a method for increasing the effective process life and chemical efficiency of use of aqueous-based developer solutions used for chemical development of photoresists such as are used in the printed circuit industry. The activity is maintained by regenerating some of byproducts during the process to active carbonate, by controlled additions of alkaline hydroxide instead if conventional carbonate solution. The pH and thus the development speed can automatically be controlled at any desired constant value. This invention allows simple automation of printed circuit photoresist development, with reduced chemical costs and increased chemical usage efficiency and thus reducing the industrial waste volume.
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