MANUFACTURING / JAPAN SOURCING
PCB assembly quotes: what to send beyond the BOM
A bill of materials identifies parts. It does not define the bare board, placement, firmware or the test that makes an assembled board acceptable. Quote those work packages against one released data set.
The same BOM can produce different offers
Imagine a buyer sending the same component list to two EMS companies. One quote covers buying and placing parts on supplied boards. The other includes bare-board procurement, programming and a functional test. The prices answer different requests, even before component availability differs.
Marantz Electronics distinguishes information for a rough estimate from data needed for mounting: its FAQ identifies assembly information and, depending on the work, Gerber and placement-coordinate data.[1] Ask your chosen EMS for its accepted formats; a file extension alone does not settle the scope.
- 1Bare board: fabrication data, drawing and supply responsibility
- 2Assembly: BOM, placement, orientations and purchased/supplied parts
- 3Delivery: firmware, inspection, test result and supplied-part balance
Three work packages to scope in the quotation. This is not a complete manufacturing sequence or a prescribed test method.
Send one release, not a folder of competing revisions
Put the board identifier and revision on a release index. List the BOM, fabrication package, assembly drawing, placement data and any programming or test instructions by filename and revision. Identify which is authoritative if the files disagree; resolve conflicts before production release.
The BOM should distinguish the exact manufacturer part number from a description or distributor reference. Mark unpopulated positions and approved alternatives clearly. A proposed substitute is a question for approval, not permission to mount any part with a similar rating.
Ask for a quoted boundary beside each work package
The table is a starting point for an enquiry, not a guarantee that every supplier needs or accepts the same data. If you do not have a required file, ask whether preparation or design work can be quoted separately.
| Work package | Provide or identify | Confirm in the offer |
|---|---|---|
| Bare PCB | Provide or identifyFabrication files, stack-up/drawing, revision and quantity | Confirm in the offerWho buys the board; fabrication requirements and inspection included |
| Parts and mounting | Provide or identifyBOM, assembly/placement data and unpopulated positions | Confirm in the offerProcured versus supplied parts; substitutes need approval |
| Programming | Provide or identifyReleased image/reference, target device and procedure | Confirm in the offerWho writes and verifies it; version record and per-unit configuration scope |
| Inspection and test | Provide or identifyAcceptance requirements, test specification and fixture information | Confirm in the offerVisual/AOI/X-ray/electrical/functional scope; results and exclusions |
| Delivery and leftovers | Provide or identifyMarking, packing and supplied-part inventory needs | Confirm in the offerDelivered boards, remaining parts, losses and repeat-order records |
Name the test instead of writing “tested”
Marantz’s FAQ lists visual inspection, X-ray and functional testing, and describes fixtures built to a customer test specification.[1] These names describe different work. An offer that includes visual inspection should not be read as proof that the board’s intended functions were exercised.
For a simple controller board, state what the functional test must demonstrate, the operating configuration and pass/fail criteria. Identify the fixture, software and reference sample needed to run it, who supplies them, and what result record is required. Keep test development and the recurring production test as separate quoted tasks.
Keep programming and supplied parts in the comparison
Marantz also describes ROM writing and incoming inspection as services.[2] Ask whether those activities are in this quote. For programming, agree how the released image, verification result and any per-unit configuration will be controlled; arrange protected provisioning separately where needed.
For buyer-supplied components, agree quantities, packaging format, usable stock checks, process losses and what will be returned or held for repeat work. Before approval, reconcile the work packages and open questions across all offers. A common BOM is useful, but a common accepted deliverable is what makes the prices comparable.
Questions to send your supplier
Open supplier questions
Board ID / revision / intended use: Build quantity and required date: Release index: BOM, fabrication, assembly/placement, programming and test documents: Please distinguish bare-board procurement, parts procurement, mounting, programming, inspection and functional testing. Identify purchased versus supplied items, approved alternatives and open deviations. State fixture/test-development costs, recurring test scope, result records, marking and packing. Confirm supplied-part balance, returns and records retained for repeat orders. Destination:
Sources
- Marantz Electronics — EMS FAQ
Public FAQ distinguishes estimate inputs, mounting data and inspection services. These are one supplier’s requirements, not a universal file contract.
- Marantz Electronics — Components procurement
Public descriptions of procurement, proposed alternatives, ROM writing and incoming inspection. Individual capability and pricing remain unconfirmed.