Direct correlation between mechanical failure and metallurgical reaction in flip chip solder joints
- 1 April 1999
- journal article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 85 (7) , 3882-3886
- https://doi.org/10.1063/1.369779
Abstract
We tested flip chip solder bonded Si samples under tensile and shear loading as a function of annealing time at 200 °C. The solder bump was eutectic SnPb and the underbump thin film metallization was Cu/Cr deposited on oxidized Si. We found that the failure mode is interfacial fracture and the fracture strength decreases rapidly with annealing time. From scanning electric microscope observations, the fracture occurs at the Cu–Sn/Cr interface. We conclude that it is the metallurgical reaction that has brought the solder into direct contact with the Cr surface. The weak joint is due to the spalling of Cu–Sn compound grains from the Cr surface, especially near the edges and corners of the joint.This publication has 7 references indexed in Scilit:
- Size dependent dewetting and sideband reaction of eutectic SnPb on Au/Cu/Cr multilayered thin filmJournal of Materials Research, 1998
- Future challenges in electronics packagingIEEE Circuits and Devices Magazine, 1998
- Microstructures of phased-in Cr–Cu/Cu/Au bump-limiting metallization and its soldering behavior with high Pb content and eutectic PbSn soldersApplied Physics Letters, 1997
- Dewetting of molten Sn on Au/Cu/Cr thin-film metallizationApplied Physics Letters, 1996
- Spalling of Cu6Sn5 spheroids in the soldering reaction of eutectic SnPb on Cr/Cu/Au thin filmsJournal of Applied Physics, 1996
- High Sn solder reaction with Cu metallizationScripta Materialia, 1996
- Encapsulants used in flip-chip packagesIEEE Transactions on Components, Hybrids, and Manufacturing Technology, 1993