Issue link: https://iconnect007.uberflip.com/i/1527613
46 DESIGN007 MAGAZINE I OCTOBER 2024 Partial HDI can be the perfect solution for designers faced with escape routing from tight- pitch BGAs. But there are a variety of material, signal integrity, and DFM trade-offs to under- stand before you get fully into partial HDI. We asked Stephen Chavez to explain the fun- damentals, as well as the details, of this promis- ing process. Are you using partial HDI? Andy Shaughnessy: What does a partial HDI PCB look like? Partial HDI: A Delicate Balance Stephen Chavez: A partial high density inter- connect (HDI) PCB looks similar to a tradi- tional PCB but with HDI features on some layers, but not all layers. It usually involves a combination of standard through-hole vias along with laser-drilled microvias and possibly buried/blind vias in the outer layers. e inter- nal layers may be manufactured using conven- tional PCB processes, while only specific lay- ers have the finer features associated with HDI construction. Feature Interview by the I-Connect007 Editorial Team