Short answer: A PCB assembly quote needs six things: (1) fabrication data as Gerber RS-274X or ODB++ including drill files and stack-up, (2) a bill of materials with manufacturer part numbers and reference designators, (3) a pick-and-place (centroid) file, (4) an assembly drawing showing polarity and any special instructions, (5) quantities for the prototype and a 12-month forecast, and (6) quality and test requirements such as IPC-A-610 class, coating and functional test. With these an EMS can quote in 1–2 working days; without them every gap becomes a question cycle.
The checklist
| # | File | Format | Why it matters |
|---|---|---|---|
| 1 | PCB fabrication data | Gerber RS-274X / X2 or ODB++, Excellon drill, stack-up, fab notes | Bare board price, layer count, finish, tolerances |
| 2 | Bill of materials (BOM) | XLSX/CSV: ref designators, quantity, manufacturer, MPN, description, package | 60–75 % of the price is here; MPNs avoid guesswork |
| 3 | Pick-and-place file | CSV/TXT: ref, X, Y, rotation, side | Machine programming, placement count, double-sided check |
| 4 | Assembly drawing | PDF: polarity, pin 1, do-not-populate, mechanical parts | Prevents wrong orientation and DNP errors |
| 5 | Quantities | Prototype qty + 12-month forecast | Reels vs cut tape, NRE amortisation |
| 6 | Quality and test requirements | IPC-A-610 class 2/3, conformal coating, ICT/functional test, traceability | Process route and test fixture cost |
Optional files that speed things up
- 3D model or STEP of the assembled board for clearance checks.
- Schematic PDF: lets the reviewer understand the circuit during DFM.
- Firmware or test software, if the EMS should program and test the boards.
- Approved alternates (AML) per BOM line.
- Panel drawing, if you already have a preferred panel.
The five most common mistakes
- BOM without manufacturer part numbers: “10k 0402” is not orderable.
- Quantities as “TBD”: the price per board depends on them more than on anything else.
- Gerbers without a drill file or stack-up.
- Reference designators that differ between BOM, pick-and-place and silkscreen.
- No polarity marks on the assembly drawing for diodes, LEDs and electrolytic capacitors.
Key facts
- Complete file set → quote in 1–2 working days at Comtec Labs.
- Every missing item typically costs one question cycle (1–3 days).
- ODB++ carries fabrication, assembly and netlist data in one package and reduces ambiguity.
- Comtec Labs runs a DFM review on every quote; findings come back with the price.
Send it to Comtec Labs
Zip the six items and send them via the contact page or straight to info@comteclabs.com. You receive a prototype and a series price, the NRE as separate lines and the DFM findings we would fix before building.
Frequently asked questions
Can you quote from a schematic only?
A budgetary estimate, yes. A firm quote needs the Gerber or ODB++ data and a BOM with part numbers.
Gerber or ODB++, which is better?
Both work. ODB++ bundles fabrication, assembly and netlist data in one package and removes most ambiguity; Gerber X2 with a drill file and stack-up is equally fine.
Do you need the schematic?
Not for the price, but it helps the DFM review and is required if we test or debug the boards.
What if my BOM has parts that are out of stock?
We propose form-fit-function alternates in the quote and mark them for your approval.
Ready to reduce PCB surprises?
Comtec Labs offers a full suite of services to streamline your workflow:
PCB design service
PCB prototyping service
PCB component sourcing
PCB component assembly
PCB testing service
PCB repair and modifications
Printed circuit board production
PCB mass production