Abstract: In wet process hot dip galvanising use is made of a flux which melts at below 500.degree.C and consists of 30 - 70% by weight magnesium chloride and 20 - 70% by weight sodium chloride and/or potassium chloride.
Abstract: A method for the production of a material for printed circuits is disclosed. A temporary base is coated by electroplating with a thin, unbroken and unpatterned metallic layer having a thickness less than 17 .mu.m and the free surface of said metallic layer is bonded to a final insulating base. The temporary base is thereafter removed and the desired wiring pattern is produced by a process comprising etching of the metal layer. A material for use in production of printed circuits is also disclosed comprising a temporary base which is coated by electroplating with a thin, unbroken and unpatterned metal layer having a thickness less than 17 .mu.m. Said material can comprise a final, insulating base bonded to the free surface of the thin metal layer.
Abstract: A process is provided for tabletting spherical dental amalgam alloy. The process comprises treating the particles of spherical alloy by contacting them with a hydrochloric acid solution of cupric chloride, separating the acidic cupric chloride solution from the spherical alloy particles, washing the spherical alloy particles with water, drying the spherical alloy particles to remove residual water and then compacting the treated spherical alloy particles into a solid form such as a tablet.
Abstract: A process for the stabilization of an aluminum part, such as a semiconductor lead frame, which includes the step of coating said aluminum part with an alcohol solution containing boron, phosphorous and a metal selected from the group consisting of gold, palladium, rhodium and platinum. The solution is prepared by mixing phosphorous pentoxide in an alcohol solvent. The dissolution of the phosphorous pentoxide is exothermic and the temperature of the solution will rise during the reaction. Then, boric anhydride and a salt of gold, palladium, rhodium or platinum is added. The solution strips any aluminum oxide from the surface of the part while also removing any organic contamination and while depositing a layer of the gold, platinum, rhodium or palladium onto the surface of the aluminum part. The process is particularly advantageous for preparing aluminum lead frames for wire bonding during semiconductor device assembly.
Abstract: Objectionable ripple formation in continuous hot-dip coating is avoided by using a single set of blowing nozzles and directing the gas streams downwardly against the strip at an angle between the strip and the center line of the gas stream of from about 0.degree. to about 45.degree., preferably from about 20.degree. to about 40.degree.. The technique is particularly useful at low line speeds of 150 feet per minute or less, especially at high coating weights of 1.5 ounces per square foot or more.