Modeling Kirkendall Vacancy Flux in Ternary SAC Solder Interfaces
Modelling vacancy transport in ternary SAC interfaces enables precise prediction of Kirkendall microvoid growth, preventing latent failure in high-reliability packaging.
FIB Cross-Sectioning
Meaning
High-resolution imaging techniques that utilize a focused ion beam to excise microscopic samples from semiconductor devices allow for the precise observation of internal structures. Using fib cross-sectioning enables engineers to view sub-surface features at the nanometer scale without the mechanical damage caused by traditional grinding and polishing. This method is essential for identifying voids, cracks or contamination in advanced electronic packages.
It is performed inside a vacuum chamber where a stream of gallium ions removes material with extreme accuracy.
Sample Excavation
The ion beam acts as a microscopic scalpel that cuts a trench into the area of interest on the component. This application of fib cross-sectioning allows the technician to target a single transistor or a specific layer of a solder joint.
Subsurface Observation
Once the trench is created, the vertical wall of the cut is imaged using a scanning electron beam. This dual-beam approach provides a direct view of the internal layers while they are still in their original orientation.
Analysis Precision
The resolution achieved by this process is far superior to optical methods and can reveal defects that are only a few atoms wide. Because the process is highly localized, the rest of the component remains intact for further electrical testing or physical analysis. Laboratory reports include these images to prove the cause of a failure to the manufacturer.
The speed of the excavation makes it a preferred choice for rapid prototyping and root cause investigation in modern production facilities.