In situ fixture for multi-modal characterization during electromigration and thermal testing of wire-like microscale specimens

• In situ electromigration jig for both X-ray microtomography and EBSD
• Initial elucidation crystallographic and microstructural effects on electromigration

A fixture has been designed and fabricated to facilitate accelerated electromigration (EM) testing with in situ imaging capability of wire-like specimens. This fixture design has enabled microstructural evolution studies in microscale (100 μm–500 μm in dimension) solder volumes. The fixture allows application of thermal and electrical stimulus to wire-like solders in situ during multi-modal characterization. The design is compatible with surface (2D) characterization techniques including optical microscopy (OM) and scanning electron microscopy (SEM) based analyses. SEM characterization using the fixture has also been coupled with electron back-scatter diffraction (EBSD). Grain orientation image maps (OIMs) were obtained for in situ crystallographic microstructural analysis of the test volumes. The fixture is also compatible with X-ray computed tomography (non-destructive and 3D), or XCT, analysis of microstructure volume. To apply 2D techniques, a facet has been polished into the solder volumes prior to mounting within the fixture, though this surfacing requirement is not required for XCT characterization. A demonstration of the fixture's successful EM testing function is provided. The compatibility of the fixture with these characterization tools is also demonstrated. Both functional thrusts of the new in situ fixture's design have been accomplished through the fixture's form which is provided in reproducible detail.