In-situ monitoring of interface delamination by local thermal transducers exemplified for a flip-chip package

Abstract

We have developed a novel, rapid, robust and non-destructive experimental technique for in-situ monitoring of delamination of interfaces for electronic packages. The method is based on a simple thermal transducer matrix of so-called THIXELS (thermal pixels) which allows a spatially resolved real-time image of the current status of delamination. The transducers are small metal wire meanders which are driven and electrically read out using the well-known 3-omega method. This method has special advantages over other thermal contrast methods with respect to robustness, sensitivity and signal-to-noise ratio. Notable is the absence of cross-effects. The proof of concept has been furnished on an industry-grade flip-chip package with underfill on an organic substrate. The technique is especially powerful for buried interfaces, where time-honoured methods like scanning acoustic microscopy (SAM) cannot be applied. As the technique effectively performs a thermal diffusivity sensitive scan, it may not only be useful for stress testing during package qualification, but sensor applications on other fields of health monitoring seem also possible

A Comprehensive Review of Sustainable Assessment and Innovation in Jet Grouting Technologies

“…Thermal methods use thermal monitoring to assess column dimensions through the heat generated by the grout curing process [32][33][34]. This real-time, non-destructive technique provides insight into column integrity and size, but can be affected by soil types and hydration reactions, as noted by Wunderle et al [35]. The challenge is to refine these methods to reduce error margins and adapt them to different geotechnical contexts.…”