Improve the HDI PCB board’s overall signal integrity
Signal Integrity: One realized benefit of the HDI PCB design for this project is the improvement in electrical performance. The smaller parts used here have shorter internal wire lengths, reduced rise times, and lower power requirements when compared to their larger, alternative packages. This HDI PCB design extends the advantages of these smaller features. The μVias have considerably less electrical parasitic capacitance and inductance than thru-hole vias, partly due to significantly reduced stub lengths in critical circuits. They also have a large current-carrying capacity. Thin dielectrics between signal and plane layers were required to meet overall thickness and signal impedance targets, which help to keep trace widths small (<4mils). The solid copper power planes near the outer layers help reduce noise, as well as RFI/EMI emissions, in addition to opening up internal layers for more traces, as previously mentioned. The intentional use of buried capacitance plane layers reduces the number of bypass capacitors needed, by making the HDI PCB itself work as a component. The effect of all of these characteristics works in combination to greatly improve the HDI PCB board’s overall signal integrity.
HDI PCB capitalize on the latest technologies available to increase the functionality of PCBs using the same or less amount of area. This advancement in HDI PCB technology is driven by the miniaturization of components and semiconductor packages that supports advanced features in revolutionary new products. This includes touch screen computing, 4G network communications and military applications such as avionics and smart munitions.
High Density Interconnected (HDI) printed circuit boards have made technological advancements in electronics possible. They have been referred to under a variety of names: Sequence Build Up (SBU), Microvia Process (MVP), and Build Up Multilayer (BUM) boards, to name a few. Eventually the IPC (Association Connecting Electronics Industries) adopted the HDI PCB term for consistent terminology across countries and industries.