| About this Abstract |
| Meeting |
2010 TMS Annual Meeting & Exhibition
|
| Symposium
|
Pb-Free Solders and Emerging Interconnect and Packaging Technologies
|
| Presentation Title |
Internal Strain Evolution during Thermal Cycling in a Row of Lead-Free Solder Joints in a Flip Chip Ball Grid Array Package |
| Author(s) |
Bite Zhou, Thomas R. Bieler, Guilin Wu, Stefan Zaefferer, Tae-Kyu Lee, Kuo-Chuan Liu |
| On-Site Speaker (Planned) |
Bite Zhou |
| Abstract Scope |
In-situ measurement of transmission diffraction patterns during thermal cycling of a single row from a 44x44 flip chip ball grid array package were analyzed to characterize internal strain evolution. The analyzed joints were in the ball grid array with a 1 mm pitch and an 18x18 mm die. The as-assembled package on its printed circuit board was sliced to provide a row that went through the center of the package. A thermal cycling stage was placed in a synchrotron beamline so that patterns could be measured periodically during a thermal cycle, in about 20% single, 40% bi-, and 40% tri-crystals (the method was confirmed with serial sectioning on other samples). Due to the different orientations in each joint, the effect of the anisotropic expansion coefficient on strain history in each in each of the crystal orientations is analyzed to identify how crystal orientations affect strain history during a thermal cycle. |
| Proceedings Inclusion? |
Planned: Journal of Electronic Materials |