| 摘要 |
Apparatus and methods for providing a robust solder connection in a flip chip arrangement using lead free solder are disclosed. A copper column extends from an input/output terminal of an integrated circuit. A cap layer of a material comprising one of nickel, nickel alloys, palladium, platinum, cobalt, silver, gold, and alloys of these is formed on the exterior surface of the copper column. A lead free solder connector is disposed on the cap layer. A substrate having a metal finish solder pad is aligned with the solder connector. A thermal reflow is performed. The metal finish may be of nickel, nickel alloy and nickel based materials. Following a thermal reflow, the solder connection formed between the copper terminal column and the metal finish solder pad is less than 0.5 wt. %.
|
