You have a schematic and a board. SpecBuildr asks a short set of plain-English questions and turns your answers into a complete PCB specification a fab and assembly house can quote and build — stackup, copper weight, impedance and all.
A board can pass DRC and still be wrong for the fab: the stackup, copper weight, impedance control, and finish are a separate spec from the layout — and the assembly house needs its own set of answers.
Miss them and you get a board that fabs fine but fails signal integrity, or can't be assembled at your volume. SpecBuildr asks the fab-and-assembly questions in plain language and turns your answers into a spec both houses can quote from.
A fab-ready spec comes down to six things beyond the Gerbers. Here's what each means in plain terms.
What the board does and how many you need.
In plain terms: a prototype run vs. production changes the fab class.
Board dimensions and the key or critical parts.
In plain terms: how big, and what's the hardest thing to place.
Layer count and the arrangement of copper and dielectric.
In plain terms: how many layers, and how they're stacked.
Copper weight and any controlled-impedance signals.
In plain terms: current capacity and high-speed signal control.
Surface finish (ENIG / HASL), soldermask, and IPC class.
In plain terms: how pads are plated and how strict the fab is.
SMT or through-hole, one or both sides, and operating conditions.
In plain terms: how it's built and where it runs.
You answer questions about the board, its size and key parts, and how it's used; the tool builds the fab-and-assembly spec around them — layer stackup, copper weight, controlled impedance, surface finish and IPC class, and assembly notes — the parameters a fab needs beyond your Gerbers.
A complete, downloadable PCB specification: board and program, size and components, stackup, copper and impedance, finish and fab class, and assembly and environment — formatted to IPC standards so fab and assembly can quote it.
It's generated from your answers and reviewed for major physics and manufacturability violations. Treat it as a strong, quote-ready starting point, not a substitute for the fab's final DFM and impedance review.
The tool is free to use and needs no account. You keep the spec.
Five minutes of plain questions. A fab-ready specification at the end.
Start your board spec →