Oxide skin removal manner null of CuSn based copper basic

摘要

PURPOSE:To perfectly remove an oxide film formed on the surface of a Cu-Sn type copper-based alloy by annealing by successively washing the surface of the alloy with a pickling soln. contg. sulfuric acid and hydrogen peroxide each at a specified concn. and a pickling soln. contg. sulfuric acid and acidic ammonium fluoride each at a specified concn. CONSTITUTION:When an oxide film formed on the surface of a Cu-Sn type copper-based alloy by annealing is removed by washing with acidic solns., the surface of the alloy is first washed with a primary pickling soln. contg. 10-50vol.% sulfuric acid and 0.5-3vol.% hydrogen peroxide at about 20-30 deg.C for about 5 sec. The washed surface is then washed with water and further washed with a secondary pickling soln. contg. 10-50vol.% sulfuric acid and =10g/l acidic ammonium fluoride. The oxide film formed on the surface of the alloy is perfectly removed and surface properties ensuring satisfactory workability and adhesion to plating are obtd.