Advanced 3D Imaging Approach to TSV/TGV Metrology and Inspection Using Only Optical Microscopy

TL;DR

This paper presents a novel optical microscopy-based method combining hybrid field microscopy and photometric stereo to improve 3D visualization and defect detection in silicon and glass vias, surpassing traditional superficial inspection limits.

Contribution

The paper introduces an innovative optical microscopy approach integrating photometric stereo for detailed 3D inspection of internal via structures, enhancing defect detection and visualization capabilities.

Findings

Effective 3D reconstruction of internal via structures

Improved defect detection accuracy

Cost-effective and highly repeatable inspection method

Abstract

This paper introduces an innovative approach to silicon and glass via inspection, which combines hybrid field microscopy with photometric stereo. Conventional optical microscopy techniques are generally limited to superficial inspections and struggle to effectively visualize the internal structures of silicon and glass vias. By utilizing various lighting conditions for 3D reconstruction, the proposed method surpasses these limitations. By integrating photometric stereo to the traditional optical microscopy, the proposed method not only enhances the capability to detect micro-scale defects but also provides a detailed visualization of depth and edge abnormality, which are typically not visible with conventional optical microscopy inspection. The experimental results demonstrated that the proposed method effectively captures intricate surface details and internal structures. Quantitative comparisons between the reconstructed models and actual measurements present the capability of the proposed method to significantly improve silicon and glass via inspection process. As a result, the proposed method achieves enhanced cost-effectiveness while maintaining high accuracy and repeatability, suggesting substantial advancements in silicon and glass via inspection techniques