Use these answers to prepare a clear project brief and resolve scope before a manufacturing release.
When is HDI useful?
Fine-pitch component escape and dense layer transitions can justify microvias and build-up layers. Start with the routing need, then compare feasible architectures. Adding HDI without a defined density or packaging benefit can add avoidable cost.
Are stacked and staggered microvias interchangeable?
No. They produce different interconnect structures and process sequences. Review the complete stack-up, interface construction and reliability evidence with the selected manufacturer before committing the layout.
Does every via in a pad need the same treatment?
The required filling, capping and planarization depend on the pad, via and attachment process. An open hole can change solder distribution. State the finished surface requirement rather than relying on a generic via-in-pad label.
What should an HDI quote specify?
Include via layer spans, build-up sequence, materials, copper, fine-feature requirements and the intended acceptance evidence. Ask which structures are established production processes and which require qualification.