- A box build RFQ needs seven parts: BOM, PCB data, mechanical drawings, cable drawings, assembly instructions, test specification and packaging requirements.
- The BOM is the single document that most affects quote accuracy: manufacturer part numbers, approved alternates and consigned parts must be explicit.
- Volume should be stated as annual usage, release quantity and ramp, and quotes should be requested on one Incoterm so they can be compared like for like.
- Staged disclosure under an NDA lets you get firm quotes without sending the full design package to every factory on day one.
A box build RFQ is not a purchase request with a drawing attached. It is the document that decides whether a factory can price your product in days or has to come back with twenty questions over three weeks. Every gap in the package turns into either a clarification email or an assumption buried in the quote, and assumptions are where price surprises come from later.
Box build makes this harder than a PCBA-only RFQ, because the factory is pricing boards, plastics or metal, cables, displays, firmware loading, test, labelling and packing at the same time. If you are new to the scope, the buyer’s guide to box build assembly in Vietnam covers what the work includes and how a project typically runs.
This article is the practical checklist: what to send, in what format and why each item changes the quote.
Why incomplete RFQs cost weeks
When a factory receives an incomplete package, it has three options: decline, ask questions or quote with assumptions. Good factories ask questions, which is slow. Less careful ones quote with assumptions, which looks fast until the first-article sample shows a different connector, a cheaper plastic grade or a test that only checks power-on.
The fix is a package that answers the standard questions before they are asked. The seven parts below cover what most box-build factories need to give a firm quote.
The seven parts of a complete package
1. Bill of materials
The BOM is the single document with the largest effect on quote accuracy. Export it as a spreadsheet, not a PDF, so the factory’s purchasing team can run it through distributor pricing tools. For background on BOM structure, see the Wikipedia article on bills of materials. The columns that matter:
| Column | Why it matters |
|---|---|
| Line number and reference designators | Links each part to the PCB and assembly drawings |
| Manufacturer name and manufacturer part number (MPN) | Without an MPN, the factory has to guess the part |
| Description and package | Lets engineers spot errors in the MPN |
| Quantity per assembly | Drives material cost and scrap allowance |
| Approved alternates | Gives purchasing room when the primary part is short |
| DNP (do not populate) flag | Avoids paying for parts that are not fitted |
| Turnkey or consigned | Shows who buys each part |
| Mechanical and packaging items | Screws, gaskets, labels, cartons and inserts are part of the BOM too |
Include mechanical and packaging lines, not just electronics. Box-build quotes often miss screws, thermal pads, foam, labels and cartons because they were never listed.
2. PCB fabrication and assembly data
- Gerber RS-274X or ODB++ files
- Board stack-up, material, thickness, copper weight and surface finish
- Centroid (pick-and-place) file
- Assembly drawing showing polarity, orientation and any hand-soldered parts
- Required workmanship class, for example IPC-A-610 Class 2
- Conformal coating or potting areas, marked on a drawing
3. Mechanical drawings and 3D models
- STEP file for every custom part and the full assembly
- 2D PDF drawings with critical dimensions, tolerances, material grade, colour and surface finish (texture reference, paint or anodise spec)
- Whether tooling is new or existing, and who will own it
- Expected cavity count or tool life, if you have a view on it
If the enclosure is injection-molded, the tooling line is often the largest one-time cost in the quote. Stating expected lifetime volume lets the factory propose the right tool steel and cavity count.
4. Cable and harness drawings
- Wire gauge, colour, insulation type and length with tolerance
- Connector and terminal MPNs, including crimp terminals
- Pin-out table for each end
- Labels, sleeving and routing requirements inside the enclosure
- Workmanship standard: IPC/WHMA-A-620, with class stated
5. Assembly instructions
An exploded view with a sequence is enough at quote stage. Mark screw torque, adhesive or thread-locker points, label positions and where the serial number goes. If there is a step that is easy to get wrong (a ribbon cable that can be fitted backwards, a gasket that must seat fully), say so. It affects both labour time and the fixtures the factory will propose.
6. Test specification
This is the section most often left vague. A usable test spec answers:
- What is tested on every unit (power rails, interfaces, radio, display, audio, sensors)
- Pass and fail limits for each measurement
- Firmware image, version control and how it is loaded
- Calibration steps and which data must be logged against each serial number
- Whether burn-in is required, for how long and under what load or temperature
- Who designs and pays for the functional test fixture
- What test data you want delivered, and in which format
Ask for fixture cost to be quoted as its own line. It makes quotes easier to compare and makes future fixture changes visible.
7. Packaging, labelling and shipping
- Retail box artwork or dieline, inserts, manuals and accessories
- Product label and carton label content, including barcodes
- Country-of-origin marking requirements for the destination market
- Master carton spec and pallet pattern
- Destination country and preferred Incoterm
- HS code, if you already have one classified
Commercial data: volume, schedule and Incoterms
Factories price labour, setup and material breaks against volume, so give them more than a single number.
| Field | Example of a useful answer |
|---|---|
| Annual usage estimate | 12,000 units per year, year one |
| Release quantity | 1,000 units per order, monthly |
| Pilot lot | 50 to 100 units before the first production release |
| Ramp | Year two estimate, if known |
| Required first delivery | Target week, plus whether it is firm |
| Incoterm for quote | One term for all suppliers, for example FOB or DDP |
The figures in the table are placeholders to show the level of detail, not benchmarks. Indicative lead times of 4 to 8 weeks for 500 to 10,000 units after sample approval are commonly quoted for box build, but your schedule has to be confirmed by the factory quotes you receive.
Quotes on different Incoterms cannot be compared directly. A DDP quote includes freight, duty and import handling that an FOB quote leaves to you. Ask every factory to quote on the same term under Incoterms 2020, or convert them yourself before comparing. The ICC Incoterms rules page defines where cost and risk transfer for each term.
Quality and compliance expectations
State these up front, because they change which factories can quote at all:
- Quality system required: ISO 9001 at minimum, ISO 13485 for medical, IATF 16949 for automotive
- Workmanship standards: IPC-A-610 (revision J, released 2024) and IPC J-STD-001 for soldering, IPC/WHMA-A-620 for cables
- Product compliance targets: UL, CE, FCC, RoHS and REACH as relevant
- Whether you need pre-compliance support, such as pre-scan testing before formal certification at an accredited lab
- Traceability level: lot level or serial level, and how long records must be kept
- Inspection plan: AQL levels, first-article inspection and whether you or a third party will inspect before shipment
Master checklist
| Item | Needed for a firm quote | Can follow later |
|---|---|---|
| BOM with MPNs and alternates | Yes | |
| Gerber or ODB++, centroid, assembly drawing | Yes | |
| Enclosure STEP and 2D drawings | Yes | |
| Cable and harness drawings | Yes | |
| Assembly sequence or exploded view | Yes | Detailed work instructions |
| Test specification | Draft at minimum | Final limits, fixture design |
| Packaging and label spec | Outline | Final artwork |
| Volume, release quantity, ramp | Yes | |
| Incoterm and destination | Yes | |
| Quality and compliance requirements | Yes | |
| Firmware image | Before sample build |
Protecting your IP with staged disclosure
You do not need to send full native CAD and firmware to every factory on day one. A common approach is to share in stages:
- Screening: product description, photos, volume and required processes, no design files.
- Quoting, under NDA: BOM, Gerbers, STEP files and 2D drawings. This is enough for a firm quote.
- Sampling, after selection: firmware, test software, detailed work instructions and native CAD where tooling requires it.
Sign the NDA before stage two, and number or watermark the files you send so you know which version each factory holds.
Keep revisions under control
A quoting round often overlaps with late design changes. If the BOM or enclosure changes after the RFQ goes out, send a revision note listing exactly what changed (line numbers, drawing numbers, new revision letters) rather than a fresh package with no explanation. Ask every factory to state on the quote which revision of each document it priced. Without that line, two quotes that look comparable may be based on different designs, and the difference only shows up when the first-article sample arrives.
Common RFQ mistakes
- BOM without MPNs, or with ‘or equivalent’ on critical parts
- Mechanical and packaging items missing from the BOM
- No test spec, so every factory prices a different test
- A single volume figure with no release quantity
- Quotes requested on different Incoterms
- Tooling ownership not mentioned
- Design files sent before an NDA was signed
Sending your RFQ
Once the package is together, the next step is getting it to factories whose equipment and volume range fit the product. boxbuildvn.com is an independent matching service, not a factory: you send the RFQ and we match it with up to 3 Vietnamese EMS or box-build factories, then you work directly with them. See box build assembly in Vietnam for the scope these factories typically cover.
Send your BOM and drawings through the box-build RFQ form and get matched with up to 3 Vietnamese EMS factories within 24 business hours. Free for buyers, NDA on request. If some items on the checklist are still open, mark them as draft and send the package through the RFQ form anyway, so the match can start while you finish the rest.
Frequently asked questions
Should I include a target price in a box build RFQ?
It is optional. A target price helps a factory tell you early if the gap is too large to close, which saves both sides a quoting round. The risk is that some suppliers quote just under the target instead of pricing the real work. A middle path is to share a target range after the first round of quotes, once you can see which factories understood the scope.
What file formats do factories expect for mechanical and PCB data?
For PCBs, Gerber RS-274X or ODB++ plus a centroid (pick-and-place) file and an assembly drawing in PDF. For mechanical parts, a STEP file for the 3D model and a dimensioned 2D PDF drawing with tolerances, material and finish. Native CAD files are rarely needed at quote stage and usually stay with you until tooling is ordered.
How many factories should receive the same RFQ?
Two to four is a workable number. Fewer gives you no price or capability comparison. More means you spend weeks answering the same technical questions and managing NDAs with suppliers you will never use. Pre-screen on equipment, certifications and volume range first, then send the full package only to the shortlist.
What if my test specification is not finished yet?
Send what you have and label it as a draft. At minimum, list the functions that must be verified on every unit, any calibration step and whether burn-in is needed. Factories can quote a fixture concept from that. Expect the test cost line to change once the specification is final, and ask for fixture cost to be quoted separately so the change is easy to track.
Does sending an RFQ through boxbuildvn.com commit me to anything?
No. Sending an RFQ gets you matched with up to 3 Vietnamese EMS or box-build factories whose capability fits. You decide whether to continue with any of them, and all quotes, samples and orders are agreed directly between you and the factory. It is free for buyers, with no commission on orders and an NDA on request.