PCB engineering lab
Calculate trace impedance, tolerance corners and via clearances from your stack-up dimensions, then export the study to discuss with a fabricator.
Every micron changes the answer.
50 Ω ±10% · inside target
Some corners outside target band
100 mm · εeff 3.050
After offset · 0.050 mm
Change the physical geometry. Inspect the calculated response.
Move the slider. Watch the geometry, impedance and tolerance envelope respond together.
The nominal answer is only the start.
Eight independent extremes of width, dielectric height and Dk; copper is fixed. These are model bounds, not a prediction of manufacturing yield.
Inspect all eight corners
| w / mm | h / mm | Dk | Z₀ / Ω |
|---|---|---|---|
| 0.295 | 0.162 | 4.00 | 50.77 |
| 0.295 | 0.162 | 4.40 | 48.72 |
| 0.295 | 0.198 | 4.00 | 56.99 |
| 0.295 | 0.198 | 4.40 | 54.70 |
| 0.345 | 0.162 | 4.00 | 46.45 |
| 0.345 | 0.162 | 4.40 | 44.55 |
| 0.345 | 0.198 | 4.00 | 52.43 |
| 0.345 | 0.198 | 4.40 | 50.31 |
Change it. Measure the difference.
Capture a baseline above, then change the geometry to compare impedance, delay, remaining ring and central dielectric. Your study stays in this browser tab; export it before leaving.
Model assumptions, limits & sources
Hammerstad–Jensen quasi-static surface microstrip with copper-thickness correction. Uniform Dk, uncoated trace, continuous ground. Solder mask, frequency dispersion, roughness, losses, differential coupling and via discontinuities are excluded. This is an early-design estimate, not a field solver or production approval.
Ring = (pad − production drill) / 2 − radial offset. Aspect = copper/dielectric total / production drill. Bore ≈ drill − 2 × hole-wall copper. Supplier limits shown here are editable examples. Confirm drill tolerance, plating, registration, final stack-up and a controlled-impedance coupon with your fabricator.
Hammerstad–Jensen / Qucs ↗Annular rings / Eurocircuits ↗Drilling tolerances / Eurocircuits ↗
How a PCB is made 06 STAGES ↗
An illustrated walk through the main stages of rigid PCB production. The example board below is separate from the engineering study above; export the study to keep its values.
Layers, surface finish and solder mask
These settings start a request. The fabricator confirms the final construction and manufacturing requirements.
Which Thai plants make a board like this?
4L · 100 × 80 mm · FR-4 · 1.6 mm · ENIG