A practical workbench for the decisions that must happen before PCB routing and procurement.
Build. Calculate. Compare.
Your materials determine your board thickness.
Choose prepreg construction, ply count and core dielectric thickness. The section and totals update together. Copper is counted separately from each core.
| Between | Construction | Plies | mm / ply or core | Dk |
|---|
Material data, tolerances and manufacturing limits
Prepreg presets use selected Isola 370HR reference constructions and Dk at 1 GHz. They do not represent stocked materials. Pressed thickness depends on copper coverage, resin flow and the fabricator’s process. Editable core values are dielectric-only planning dimensions. The tolerance band applies your assumption to the summed thickness; it is not a statistical tolerance analysis.
Isola material data and current construction tables. Confirm material availability, resin fill, copper balance, plated outer copper and finished thickness before release.
Find a starting width. Understand the sensitivity.
Single-ended surface microstrip over one continuous reference plane. H is dielectric distance from the trace underside to the plane surface.
Model and scope
Hammerstad–Jensen quasi-static microstrip model with finite conductor thickness correction. No solder mask, copper roughness, etch trapezoid, frequency dispersion, neighboring traces or plane voids are modeled. The width sweep varies only width; it is not a complete impedance tolerance budget. Differential pairs, asymmetric stripline and coplanar structures need a coupled-field solver and a fabricator-approved stackup.
Formula reference: Qucs technical documentation. This calculator is a layout starting point, not an impedance test report.
See the panel economics behind the unit price.
Transparent budget model in USD. All default rates are illustrative inputs, not market prices or a quotation. Replace them with your supplier’s rates.
Edit manufacturing assumptions
Uniform grid packing compares 0° and 90° rotation, without mixed-orientation nesting. Expected yield is a planning assumption, not a delivery guarantee. Processing is a user-supplied all-in panel rate; HDI cycles, special tests, tooling, freight, taxes and commercial margin must be included separately in a real quote.
Three calculations, one engineering decision
| Step | Question to answer | Output to retain |
|---|---|---|
| 1 · Construction | Can the dielectric, copper and mask meet the mechanical target? | A layer-by-layer construction table with material and thickness assumptions. |
| 2 · Impedance | What starting trace width fits the actual signal-to-plane spacing? | Geometry, Dk, model scope and sensitivity; confirm with the fabricator. |
| 3 · Cost | How do board size and order quantity change panel usage? | Panel dimensions, yield assumption, itemized rates and quantity comparison. |
Turn estimates into a fabrication agreement
- Identify the material grade and allow substitutions only through written approval.
- Separate starting foil from finished outer copper. State whether the finished board thickness includes solder mask.
- Give impedance targets and tolerances for each net class, with the signal layer and reference plane.
- Request proposed production construction, field-solver geometry and coupon/test method.
- Export your calculations, attach them to your fabrication drawing and identify them as design intent until approved.
The tools run in your browser. They do not upload a drawing or generate an automatic supplier quotation. Send an RFQ when your assumptions are ready for review.