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edfas.org 21 ELECTRONIC DEVICE FAILURE ANALYSIS | VOLUME 22 NO. 3 interferometer, theG 0 gratinghas highaspect ratio require- ments in the grating pitch and thickness. Consequently, in the conventional interferometer the G 0 grating acts like a collimator and the field of view is generally limited in a conventional three grating set up. By integrating the G 0 grating pattern as the target in the source, the field of view can be comparable to a traditional microfocus source at up to 170 degrees [7,8] (Fig.4). The advantage of having three contrast mechanisms – absorption, phase, and dark field simultaneously for effective inspection cannot be overemphasized, because each of these imaging modalities provides complemen- tary information. This broadens our understanding and perspective of the true structures, the nature of the defects, and the failure mechanism. Often, defects and abnormalities may be determined rapidly using these 2D radiographs without having to resort to time consuming tomography measurements. With dark field imaging for example, sub-micron sized defects, porosity differences between regions of the package or whether moisture or liquid are wetting crack surfaces can be visualized rapidly with a single radiograph. Detection of voids or cracks withinorganic layers are also easily visualized in the phase contrast radiograph. In other words, the time-consuming full tomography reconstruction may be unnecessary in certain cases. Thus, this technique reduces time for inspection and cost. RESULTS AND DISCUSSION Preliminary results are demonstratedusing the current setup, which used an x-ray gratingwith a designed energy of 20 keV. The experimental setup comprises a patented custom made structured tungsten source developed by Sigray Inc. The x-ray generator operates at 34 kV voltage and power of 40 W. A few samples illustrate some key capabilities of this novel x-ray imaging tool. The first sam- ple is a commercial advanced semiconductor system in package (SIP). Promising results on sidewall and lateral Fig. 4 Illustrationof themodifiedTalbot-Lau interferometer where the target of the x-ray source is incorporated in the pattern of the first grating G 0 . This overcomes the lack of flux reaching the detector and the lack of field of view. Fig. 5 Radiograph of sidewall delamination of SIP showing sidewall delamination in phase contrast (middle image) and dark field imaging (bottom image) but not in absorption contrast mode.