x-ray tomography

**X-ray tomography** is **a three-dimensional imaging method that reconstructs internal package and board structures from multiple x-ray projections** - Computed reconstruction combines many angular scans to reveal hidden voids cracks and misalignment features without destructive sectioning. **What Is X-ray tomography?** - **Definition**: A three-dimensional imaging method that reconstructs internal package and board structures from multiple x-ray projections. - **Core Mechanism**: Computed reconstruction combines many angular scans to reveal hidden voids cracks and misalignment features without destructive sectioning. - **Operational Scope**: It is applied in semiconductor yield and failure-analysis programs to improve defect visibility, repair effectiveness, and production reliability. - **Failure Modes**: Reconstruction artifacts can create false defect signatures if calibration and alignment are weak. **Why X-ray tomography Matters** - **Defect Control**: Better diagnostics and repair methods reduce latent failure risk and field escapes. - **Yield Performance**: Focused learning and prediction improve ramp efficiency and final output quality. - **Operational Efficiency**: Adaptive and calibrated workflows reduce unnecessary test cost and debug latency. - **Risk Reduction**: Structured evidence linking test and FA results improves corrective-action precision. - **Scalable Manufacturing**: Robust methods support repeatable outcomes across tools, lots, and product families. **How It Is Used in Practice** - **Method Selection**: Choose techniques by defect type, access method, throughput target, and reliability objective. - **Calibration**: Use known calibration standards and compare reconstructed geometry against reference samples before formal diagnosis. - **Validation**: Track yield, escape rate, localization precision, and corrective-action closure effectiveness over time. X-ray tomography is **a high-impact lever for dependable semiconductor quality and yield execution** - It provides deep non-destructive visibility for complex failure-localization workflows.