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What is Via-In-Pad?

Via-in-pad places a microvia directly under the component pad, enabling:

  • 0.30–0.40 mm BGA escape
  • Shortest inductive return path
  • Cleaner high-speed routing
  • Compact HDI layout

Via-In-Pad Structure

Laser drilled → copper filled → planarized → copper cap → ENIG/ENEPIG

When to Use Via-In-Pad

  • 0.30–0.40 mm BGA CPU/FPGA
  • PCIe Gen4/Gen5 / DDR4/DDR5
  • 112G PAM4 / SerDes
  • RF SiP / PA / LNA
  • Wearables / compact HDI

HDI Design Rules (Via-In-Pad)

ParameterRecommendedNotes
Microvia drill0.10–0.15 mmLaser via
Aspect ratio≤1:1Reliable plating
FillCopper fillFor BGA pad-on-via
Planarity±5 μmCritical for BGA solder
FinishENIG / ENEPIGBest wettability

Assembly & DFM Notes

  • Use ENIG / ENEPIG
  • Flat cap avoids BGA voids
  • No extra paste on filled via
  • Specify “copper-filled + planarized”

Send Your BGA Design for HDI Review

We verify fill quality, planarity, SI/PI, and assembly readiness.