5 Hidden Defects in Electronics Manufacturing

Defect detection with modern X-ray algorithms

Technical Paper

Abstract

Modern electronics manufacturing faces critical quality and reliability challenges due to
increasing complexity, miniaturization, and the widespread adoption of advanced packaging technologies with hidden solder joints. Traditional inspection methods such as automatic optical inspection (AOI) and in-circuit testing are fundamentally limited in detecting internal defects in ball grid arrays (BGAs), quad flat no-leads (QFNs), and bottom termination components (BTCs). This paper establishes Automated X-ray Inspection (AXI) as the essential technology to bridge this inspection gap through non-destructive testing. We explain the physics of X-ray interaction with matter that enables internal visualization and trace the evolution of AXI from basic 2D radiography to advanced 3D laminography and computed tomography techniques. We identify five critical hidden defects in modern electronics manufacturing: BGA geometric deviations, voids in BGA solder joints, solder defects in QFNs/BTCs, fine solder joint defects (including head-in-pillow), and the challenges of efficient inline evaluation. We show why these defects pose significant reliability risks and how they often elude traditional inspection methods. Our analysis shows that the electiveness of modern AXI in defect detection and quantitative evaluation relies heavily on sophisticated algorithmic advances. These include 3D reconstruction techniques, AI/ML integration, adaptive algorithms, advanced feature extraction, or specialized defect-specific algorithms. We also examine how high-speed inline AXI enables real-time process control, facilitates root cause analysis, improves manufacturing yields, and reduces costs. The evidence presented suggests that advanced AXI technology, supported by intelligent software
algorithms, has become essential to ensuring the quality, reliability, and performance demanded by today’s electronics industry in critical applications such as automotive, medical, aerospace, and consumer electronics.