摘要 |
A tin immersion composition of matter is disclosed comprising a compound comprising divalent tin ion, a compound comprising fluoride ion, and a compound comprising acid hydrogen ion. A process for treating an aluminum-copper or an aluminum-silicon alloy to improve the adhesion of metal layers to the alloy is also disclosed comprising contacting the alloy with an acidic tin immersion composition to produce a tin immersion coating on the alloy, and contacting the tin immersion coating with an etchant to substantially remove the tin immersion coating and produce an etched alloy surface.
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