Abstract: An apparatus and method are used for determining the cleanliness of an electronic circuit assembly (ECA) such as printed circuit boards (PCB) following noraml cleaning and flux removal processes. The apparatus and method are used to quantitatively measure the ionic and organic contaminants remaining on an ECA. The apparatus utilizes small volumes of isopropanol, a conductivity/resistivity probe and cell and a spectrophotometric analytical instrument. The apparatus generally provides for washing the "cleaned" of defluxed ECA with a measured volume of isopropanol and thereafter measuring the ionic and organic contaminants in the wash solution. The results can then be compared to a standard.

Abstract: An apparatus and method are disclosed for determining the cleanliness of an electronic circuit assembly (ECA) such as printed circuit boards (PCB) following normal cleaning and flux removal processes. The apparatus and method are used to quantitatively measure the organic contaminants such as the amount of rosin flux remaining on an ECA. The apparatus utilizes small volumes of isopropanol and a spectrophotometric analytical instrument. The apparatus generally provideds for washing the "cleaned" or defluxed ECA with a measured volume of isopropanol and thereafter measuring the organic contaminants in the wash solution by spectrometric analysis. The results can then be compared to a standard.

Abstract: Superior solder flux, e.g., rosin flux, removal compositions are disclosed which have no flash point and are substantially non-corrosive toward aluminum. These compositions consist of about 0.5 to less than 2% methanol with about 3 to 10% of one or more alcohols containing 2-5 carbon atoms the balance being an inhibited 1,1,1-trichloroethane, wherein percentages are based on volume of the total composition.

Abstract: Metal pigments when combined with methylchloroform are stabilized by the addition of small amounts of aromatic diepoxides. Other known stabilizers against metals or the active of light and heat may be incorporated.

Abstract: A stabilized methylchloroform for use in vapor degreasing which is stable in the presence of metals which contains pyrazine, dimethoxypropane, an acetylenic alcohol and a nitroalkane or a methylfuran. Such combination prevents corrosion of aluminum, iron, copper and zinc and the decomposition of the solvent.