PCB Assembly FAQs

Prepare the fabrication package, BOM, component placement data and assembly drawings for the same revision. Add quantity, sourcing responsibilities and any programming, coating, inspection or functional-test requirements. Mark missing inputs clearly. A board image can help explain the project, but it should not replace controlled manufacturing data.

Use a clear manufacturer part number, component description, package or footprint, reference designators and quantity per board. Identify approved alternatives and purchasing restrictions separately. Ambiguous generic descriptions make sourcing review harder; a manufacturer part number and matching footprint are more useful than a value alone.

It identifies component locations, board side and rotation for machine placement, together with the reference designators. Include the coordinate units and origin convention. Export and assembler conventions may differ, so confirm interpretation and review orientation rather than assuming that the same numeric angle means the same placement in every workflow.

Make the build variant explicit and use a consistent DNP or not-fitted convention in the BOM and assembly documentation. Identify which references must not be purchased or placed. Review consistency with the placement data; an omitted or conflicting reference should become an engineering question, not an automatic placement decision.

Include orientation and polarity information, variant notes, special placement or hardware instructions and any critical mechanical constraints. Identify customer-controlled workmanship details and process restrictions. Show unusual requirements clearly enough that they can be reviewed without relying on a photograph of an earlier prototype.

Export a release package from one controlled design state. Include a manifest naming the PCB, BOM, placement, drawing, firmware and test-document revisions as applicable. Check reference designators across the BOM and placement data, and remove superseded files from the release archive rather than asking production to choose among several versions.

Use the quotation to assign responsibility. In a turnkey scope, the supplier is asked to source agreed materials; in a consigned scope, the customer provides agreed items. Mixed sourcing splits that responsibility. Define ownership of bare boards, components, substitutions, shortages and excess material instead of relying on the service label alone.

State your substitution policy in the BOM or order requirements. Where approval is required, review the proposed part against electrical ratings, package, footprint, qualification and supply restrictions before acceptance. A similar value or package marking is not sufficient evidence that a part is suitable for the design.

Ask for a kit-specific requirement before shipping. Allowances depend on the part, packaging, placement process, setup needs and order size. A single universal percentage can be unsuitable for both small passive parts and high-value devices. Agree quantities, packaging format and the treatment of any shortage before scheduling the build.

Provide a packing list with manufacturer part numbers, quantities, your project or kit identifier and any traceability requirements. Keep original identification and handling labels where available. Identify storage concerns, opened packaging or unusual handling requirements so the kit can be assessed rather than silently treated as ready for assembly.

Agree the disposition before procurement or kitting. Possible arrangements include return, storage for a named repeat build or another written disposition. Confirm ownership, identification, storage conditions and any charges. Confirm the storage period and excess-component handling arrangements in writing.

An ESD control plan combines suitable handling, work areas and packaging. For susceptible items outside an ESD protected area, discharge-shielding protection is important; low-charging packaging alone is not the same function. State any project-specific ESD or packaging requirements and ask how they will be addressed.

Identify both populations and any process-sensitive parts in the request. Ask for a proposed assembly sequence, including manual operations or special tooling where needed. Confirm whether connectors, hardware, cables and mechanical work are part of the scope. Do not infer process availability or a quoted operation from a generic “PCB assembly” label.

Supply clear top and bottom placement data and assembly drawings. Identify component-height limits, process restrictions and any parts that require special treatment during the second-side operation. Ask for the fixture and handling approach where needed, and approve relevant changes rather than leaving orientation or sequence assumptions unresolved.

Visible-surface inspection cannot fully show solder joints hidden under a package. X-ray can provide information about hidden joint structures, but it does not replace every electrical or functional test. Identify the package, critical defects and required evidence so the inspection plan can be matched to the actual risk.

Solder paste inspection assesses deposited paste before reflow. Automated optical inspection examines visible assembly features. Electrical methods such as ICT and functional testing address different circuit requirements. Define the required coverage and records for each method; listing several inspection names does not mean every failure mechanism has been checked.

Define power and interface connections, firmware state, test sequence, input conditions, expected outputs, pass/fail limits and required records. Identify fixtures, software licences and customer-supplied equipment. Request review of the proposed coverage. A generic request for “100% functional test” is not an executable test procedure.

No. IPC-A-610 provides assembly acceptance criteria, while J-STD-001 addresses soldering materials, processes and related requirements. Identify the applicable edition, class and any project-specific additions. Neither document alone proves that a customer’s complete product meets its functional or regulatory requirements.

Provide an approved programming image and version identifier, plus device information, connection details, verification requirements and configuration instructions. Define serialisation, calibration, fuse or lock settings only where applicable. Share credentials or security-sensitive material through an agreed secure route, not a general web form or an unreviewed attachment.

Specify the required process and materials, coverage, keep-out areas and acceptance checks. Identify connectors, switches, test points and other surfaces that must remain accessible. Confirm compatibility with the components and downstream use. Avoid treating “no-clean” or “conformal coating” as a complete process specification.

It is an agreed review of an initial item or build before a defined next step. Specify the sample quantity, checks, documents, approver and whether production must wait for written acceptance. A sample photograph or an inspection report is not automatically permission to continue unless that release rule was agreed.

Ask the quotation to separate component availability, engineering preparation, board fabrication, fixture or programming preparation, assembly and testing. Define the release conditions and required ship date independently of transit. A requested schedule is not a confirmed commitment until the materials, scope and order acknowledgement have been reviewed.

Request a change review and identify the exact affected references, quantities and serial or lot range. Confirm what has already been procured, programmed or assembled. Agree disposition of obsolete material and any rework, retest, price or schedule impact before the revised package is used.

No. Define the supplier’s assembly and test obligations separately from the product owner’s system-level qualification and regulatory work. Request any required component, material or process evidence in the order. A workmanship acceptance result should not be described as a blanket certification of the final enclosure, software or application.