## Description
You designed a beautiful stackup — impedance is dialed in, materials are selected — and your fab house comes back with a list of manufacturing issues. Or worse: they build it, and you get warped boards after reflow.
Most designers optimize for electrical performance and forget DFM — the stackup has to be physically manufacturable.
In this ~3 minute guide we cover:
- **Stackup balance** — why top/bottom thickness must be within 10% to prevent warping, and how the tool detects imbalance automatically
- **Copper distribution** — max 2 unique copper weights, external copper at least 80% of internal average, and why uneven copper causes thermal stress
- **Layer thickness limits** — min copper 0.5 oz (17 µm / 0.7 mil), max 3 oz (105 µm / 4 mil), min dielectric 2 mil (50 µm), prepreg finished below 2 mil after press — the exact thresholds your fab checks
- **Via aspect ratio** — through-hole (10:1), laser microvia (1:1), mechanical blind (3:1), plus the auto-adjustment feature that calculates optimal drill size and resolves violations automatically
- **Hybrid stackup detection** — mixed FR4 + Rogers flagged automatically, CTE scaling differences, and why first-article runs are essential
**Takeaway:** Run DFM validation before you submit Gerbers. Five minutes of checking saves weeks of re-spins and thousands in wasted fab runs.
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