HDI layout checker
Two calculations engineers actually reach for while laying out a dense board: whether a microvia's aspect ratio sits inside IPC-2226 guidance and how much spacing a trace needs to control crosstalk under the 3H rule.
Enter your numbers, get an answer, no sign-up required.
Microvia aspect ratio checker
Checks a microvia against IPC-2226 guidance for reliable copper plating
Enter both values
3H spacing calculator
Minimum trace-to-copper spacing to control crosstalk and edge radiation
Enter a value
Reference only, not a substitute for simulation or your fabricator's own design rules. See our HDI microvias, signal integrity and EMC guide for the reasoning behind both checks.
What it checks
- Microvia aspect ratio - Enter via depth and diameter and it tells you where you sit against the 1:1 ceiling IPC-2226 sets for reliable copper plating, and the 0.75:1 range most fabricators recommend in practice. Push past 1:1 and the risk is voiding in the plated barrel, a defect that tends to surface later as an intermittent connection under thermal cycling rather than a clean failure at first test.
- 3H spacing - Enter the dielectric height between a signal layer and its nearest reference plane and it returns the minimum spacing needed to control crosstalk and edge radiation. Thinner HDI dielectrics need less physical space to hit the same multiple, part of why HDI stackups support denser routing without an automatic crosstalk penalty.
Why we built it
Both numbers come up constantly while routing a dense board, and both are quick enough to check by hand that reaching for a full simulation feels like overkill. This tool does the arithmetic so you don’t have to keep the formula in your head mid-layout. It’s a reference check, not a substitute for simulation or your fabricator’s own design rules, and it won’t catch everything a real stack-up analysis would.
For the reasoning behind both numbers, see our guide on PCB miniaturisation, thermal management and HDI design.