High-Density Interconnect (HDI PCB) boards have become essential for modern electronics. From compact IoT devices, 5G smartphones, and wearables to automotive systems and medical equipment, HDI technology enables finer lines, microvias (blind and buried), stacked vias, and higher component density in smaller footprints. When sourcing HDI PCB board suppliers, many engineers and companies face the big question: China or USA? China dominates in cost and volume, while the USA exc