Abstract: A composition for electroplating copper onto a conductive surface comprising a solution soluble copper salt and an acid electrolyte, said copper salt being present in a concentration of from about 1 to 10 grams per liter of solution and said acid being present in a concentration whereby the acid to copper ratio preferably varies between about 30 to 1 and 50 to 1. The composition is especially useful for the plating of walls of cylindrical openings having a ratio of height to diameter of at least 10 to 1 and a length of at least 0.100 inches.

Abstract: A composition for electroplating copper onto a conductive surface comprising a solution soluble copper salt and an acid electrolyte, said copper salt being present in a concentration of from about 1 to 10 grams per liter of solution and said acid being present in a concentration whereby the acid to copper ratio preferably varies between about 30 to 1 and 50 to 1. The composition is especially useful for the plating of walls of cylindrical openings having a ratio of height to diameter of at least 10 to 1 and a length of at least 0.100 inches.Also disclosed is a device for measuring throwing power of a plating solution. The device comprises two anodes and a cathode suspended in a chamber adapted to contain a plating solution. The cathode is suspended between said anodes and comprises two flat electrode portions in electrical contact with each other, in parallel relationship to each other and spaced apart from each other to define a space containing plating solution.