Fixture for in situ electromigration testing during x-ray microtomography

Abstract

Systems and fixtures for mounting, under mechanical constraint, wire-like or fiber-like samples of a high aspect ratio and down to 100 micrometers in diameter are disclosed. A region of interest along the length of the sample resides between and beyond a mechanical constraint on either side, allowing access to the region of interest for a wide number of characterization probes. The fixture may provide electrical isolation between two retaining blocks by means of a dielectric support member. The design may achieve minimal thermal expansion along the length of the sample by the material selection for the dielectric support member. Electrical contact may be introduced to the sample through conductive constraints in the retaining blocks. The fixture may have a minimal size perpendicular to the length axis of the sample to facilitate high probe fluxes when a diverging probe is used. The fixture may provide high x-ray transparency between the retaining blocks. The systems and fixtures as described therefore may provide a means for performing electrical and thermal testing on samples, including but not limited to solder butt-joints, across multimodal in situ characterization and imaging techniques to analyze dynamic electromigration.