摘要 |
A method for plating solder is provided. In accordance with the method, a die having a seed metallization thereon is provided. The seed metallization is microetched (85) with a solution comprising an acid and an oxidizer, thereby forming an etched seed metallization. An under bump metallization (UBM) is then electroplated (87) onto the etched seed metallization, and a lead-free solder composition, such as SnCu, is electroplated (91) onto the UBM. A method for reflowing solder is also provided, which may be used in conjunction with the method for plating solder. In accordance with this later method, the substrate is subjected to a seed metallization etch (137), followed by a microetch (141). A solder flux is then dispensed onto the substrate (147) and the solder is reflowed (149). |