Issue link: https://iconnect007.uberflip.com/i/1540184
68 DESIGN007 MAGAZINE I OCTOBER 2025 • Layer registration: UHDI's multiple layers must be precisely aligned within <10 µm • Material sensitivity: UHDI's advanced res- ins and films may be optically inconsistent or semi-transparent Automated Inspection Technologies High-resolution Automated Optical Inspection (AOI) • Defect detection threshold down to 1.5–2 µm • Z-axis focus control using dynamic focusing for non-planar flex or HDI surfaces • Uses in-line with real-time pass/fail decisioning • CAD-to-board comparison with Gerber/CAM data overlay Laser Scanning Systems • Non-contact scanning of microvia depth • Surface roughness and flatness • Identifies microvia voids and incomplete fill • Taper and geometry analysis AI-driven Defect Recognition • Image acquisition • Reduces false positives • Learns from production data to improve classification over time • Feedback loop to improve process control X-ray/CT (AXI) Inspection • 2D X-ray imaging for voids, large defects and BGA alignment • 3D CT (Computed Tomography) for cross-sec- tional slicing of PCB stackup in high resolution • Detects buried microvia issues, inner-layer misregistration, and contamination • Lamino-CT (layer-by-layer scanning) for planar inspection Digital Twin and Inline Metrology • Real-time comparison of measured data with CAD-defined features • Enables predictive maintenance and in-pro- cess quality correction • Root cause traceability connecting defects with process anomalies • Predictive quality control identifying potential failures based on past data Case Study UHDI in Biomedical Implants (Hypothetical) A manufacturer of implantable neurotech circuits uses: • 2 µm AOI for trace analysis • Laser scanning for via depth validation • AI-based classification trained on neurocircuit defect data • Integrated MES (manufacturing execution sys- tem) for traceability This process ensures FDA-compliant reliability and high-yield production for medical-grade UHDI boards. Note: While hypothetical, many of these tech- niques are currently being used and/or explored across most market sectors. Future Direction As UHDI technologies continue advancing to meet the needs of AI hardware, medical devices, and aerospace systems, the future of automated inspection will be shaped by smarter, faster, and more autonomous systems. These systems will go far beyond defect detection, integrating real-time learning, predictive analysis, and deep process integration to close the loop between design, fab- rication, inspection, and yield optimization. There are exciting new ways to utilize the dual revolution of UHDI and auto- mated inspection to position compa- nies as leaders in precision electron- ics and smart man- ufacturing. Some of these include: Ad va nt a g e s of U H D I - O pt i m i ze d I n s p e ct i o n Syste m s Capability Benefit Ultra-fine defe ct resolution Ensures zero-defe ct manufacturing Real-time de cision-making Re duc es rework and scrap AI + machine learning inte gration Improves long-term reliabilit y and y ield Automate d data lo gging Enables trac eabilit y and re gulator y c omplianc e Adaptive pro c ess c orre ction C loses fe e dback lo op b etwe en design and fabrication