AstroPCB Capability
Via in Pad for Fine-Pitch PCB Assembly
Via in pad is a useful HDI technique when fine-pitch devices leave limited escape routing. It requires a fabrication process that addresses fill, cap, flatness and finish so the assembly surface remains reliable.
Engineering focus
Via in pad is a useful HDI technique when fine-pitch devices leave limited escape routing. It requires a fabrication process that addresses fill, cap, flatness and finish so the assembly surface remains reliable.
- Via-in-pad geometry for fine-pitch BGA escape
- Fill, cap and surface-finish requirements
- Assembly alignment and pad-flatness considerations
What to include in your RFQ
Useful manufacturing reviews begin with the actual fabrication data and the requirements that cannot move. Include the current Gerber, ODB++ or IPC-2581 package, fabrication drawing, quantities, target delivery and any electrical, thermal, material or documentation constraints.
- Current fabrication data and stack-up intent
- Relevant design-rule, test and reliability requirements
- Quantities, schedule and assembly context
Related engineering resources
HDI PCB Manufacturer
Explore HDI fabrication planning.
Capped Vias
Review planar via construction.
Via in Pad Guide
Read the design guide.
Move the project forward
Share the available design package and the decisions still open. AstroPCB will help frame a practical manufacturing path before release.
AstroPCB-published capability data · Updated September 18, 2026
Engineering capability snapshot
These are published engineering reference points for quotation and early design planning. Final construction, tolerances and producibility are confirmed through DFM review against the actual stack-up, material, copper distribution and quantity.
| Capability | Published reference |
|---|---|
| HDI build-up | Up to 7-step HDI; stacked or staggered microvia strategies reviewed by DFM. |
| Heavy copper | Up to 10 oz copper for suitable FR-4 heavy-copper constructions. |
| Fine features | Published quotation range reaches 3 mil line/space and 0.10 mm mechanical drill, subject to construction review. |
| Impedance control | Controlled-impedance options to ±8%, with stack-up confirmation required. |
| Via and finish options | Epoxy-filled and capped vias; HASL, lead-free HASL, ENIG, hard gold, immersion silver, immersion tin and ENEPIG options. |
Via-in-pad needs a fabrication and assembly decision together
AstroPCB supports epoxy-filled and capped via structures for designs where fine-pitch component escape and pad planarity require a via-in-pad approach. The final method is confirmed against the device, finish and assembly process.
- Identify BGA or fine-pitch component locations that require via-in-pad.
- Specify any pad-flatness, finish or inspection expectations.
- Review the approach with the HDI build-up rather than treating it as an isolated feature.