Influence of Na₂SO₄ Electrolyzed Oxidizing Water on Copper Iron Alloy for Lead Frame after Heating Processing

Abstract

This paper describes the influence of Na₂SO₄ electrolyzed oxidizing water (It abbreviates as EO water) on copper iron alloy for lead frame after heating processing. First, the etching characteristics of Na₂SO₄ EO water against the test pieces surface of the heating processing was clarified using chemicals for comparative immersion experiments. The comparative study showed that as for the etching efficiency, Na₂SO₄ EO water was superior and the influence to exert on the chemical composition in the test piece surface was small, compared with H₂SO₄ solution. Also, it puts on Na₂SO₄ EO water uniformly to the copper iron alloy surface after oxidation layer removal, too, by the etching. Next, by the observation using SEM image, the influence of Na₂SO₄ EO water on the surface shape of copper iron alloy for lead frame was clarified. The results indicated that when using Na₂SO₄ EO water, little occurrence of alien substance occurs and the surface becomes smooth than H₂SO₄ solution. Lastly, as for the test piece after heating processing, it did the surface oxidation layer removal experiment by the immersion. The results show that Na₂SO₄ EO water can remove the surface oxidation layer of the test pieces more efficiently compared with H₂SO₄ solution.