NCAB Group: UHDI PCBs vs. IC substrates: Navigating the overlap in advanced packaging

As advanced packaging technologies evolve, the boundary between Ultra High-Density Interconnect UHDI printed circuit boards (PCBs) and integrated circuit (IC) substrates is becoming increasingly difficult to define. The design and requirement differences between these two domains, the packaging industry continues to drive PCB development and miniaturization, pushing the limits of traditional board technology into what we refer to as UHDI. As a result, hybrid solutions are emerging designs that exhibit characteristics of both PCBs and substrates commonly referred to as Substrate-Like PCBs (SLPs). These hybrids challenge conventional definitions and demand new approaches to design rules, materials, and manufacturing processes. Through comparative analysis and real-world examples, to clarify the functional and structural distinctions while addressing the implications of this technological overlap. To support engineers and decision-makers in navigating this increasingly complex design landscape.