HDI Layer Stackups for Large Dense PCBs

With the significant increase in integrated circuit (IC) and field programmable gate array (FPGA) package pin counts and densities, the use of classical through-hole technology is resulting in a explosion of PCB layer counts, and thus in an explosion in product costs and size. The use of High Density Interconnect (HDI) and microvias can help designers avoid these dense BGA packages and reduce PCB layers and size. However, one must use the correct HDI/microvia configurations and the proper PCB layout tools. This paper discusses the various HDI technologies and the best approaches for successfully taking advantage of this technology.