| US 7,601,612 B1 | ||
| Method for forming solder joints for a flip chip assembly | ||
| Raj N. Master, San Jose, Calif. (US); Junaida A. Bakar, Penang (Malaysia); Diong H. Ding, Penang (Malaysia); and Srinivasan Parthasarathy, Santa Clara, Calif. (US) | ||
| Assigned to GlobalFoundries Inc., Grand Cayman (Cayman Islands) | ||
| Filed on Oct. 24, 2005, as Appl. No. 11/255,971. | ||
| Int. Cl. H01L 21/00 (2006.01) | ||
| U.S. Cl. 438—455 [438/106; 438/107; 438/108; 257/772; 257/E23.023; 257/E23.026; 257/E21.508] | 17 Claims |
| 1. A method of forming a solder joint for a package arrangement, with a dispersed Sn microstructure and minimized grain boundaries,
comprising the steps of:
providing a flip-chip on a package, the flip-chip having solder bumps to be connected by electric solder joints to pads on
the package;
reflowing eutectic solder at a solder bump/pad interface with a eutectic reflow profile configured to achieve eutectic solder
joints having substantially evenly distributed Sn grains and minimized grain boundaries.
|