Role Of X-Ray Technologies In Device Reliability: From Wafer to Package

Presented at the 2026 IEEE Hybrid Bonding Symposium, Jan 21-22, 2026 in Silicon Valley.  More information below.
(20:50 + Q&A) Jeff Gelb, Sigray Inc.
Summary: 3D X-ray imaging has become widely adopted in failure analysis (FA) workflows due to its ability to non-destructively visualize internal structures with high resolution. Traditional 2D inspection tools are often insufficient for detecting hidden defects like voids, delamination, and misalignment in next-generation packages, due to shadowing effects or limitations of the tool’s spatial resolution. The 3D approaches of computed tomography and computed laminography provide the unique ability to image intact devices and isolate specific layers of interest, which may be buried within a complex 3DHI package. Recent advancements in X-ray technologies have overcome these limitations by integrating advancements in X-ray source, detector, and system design. For practical purposes, this now allows for routine scanning resolutions down to 300 nm and the ability to scale this capability to large PCB integrations, multi-die loading trays, or even wafer-forms, with scan times in minutes.
For the inspection of hybrid bonds, the high spatial resolution of the inspection system is of critical importance to detecting both the bonds themselves and any defects within. As structures shrink to the single-micron regime, high-resolution X-ray inspection provides a rapid means of detecting and classifying defects observed within a hybrid-bonded structure, from shift- and bridge-type defects to voids and size defects. For production-stage detection, these high-resolution X-ray inspection tools may additionally be outfitted with fab automation capabilities, linking and extending inspection process recipes from the FA / R&D labs into the production fabs.
This talk will explore recent advancements in X-ray technologies, focusing on their enhanced capabilities in resolution and throughput, which are crucial for practical and scalable inspection and metrology. We will also highlight the growing importance of high-resolution analytical techniques like X-ray fluorescence (XRF), which provide both elemental and structural information and are increasingly adaptable for production environments. Additionally, we will introduce X-ray Assisted Device Alteration (XADA), a new 3D, spatially selective method that builds upon traditional laser-based alteration (LADA) techniques, particularly relevant for new backside power delivery architectures.
Bio: Jeff Gelb is Director of X-Ray Microscopy at Sigray in Benicia, California, USA, focused on next-generation 3D X-ray imaging for semiconductor failure analysis and in-line part inspection. He studied physics at UC Santa Barbara and joined Xradia in 2006, working with multi-scale 3D tomography, which carried forward into his later work with correlative microscopy at ZEISS. Jeff completed a Master’s degree in Materials Engineering at San Jose State in 2017, with a research emphasis in developing non-destructive characterization routines for commercial lithium-ion batteries. Jeff joined Sigray in 2017 and is excited about the future of 3D imaging, with much of his current work focused on automation, software, and data capture and processing workflows.

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