Surface-mount assembly
SMT PCB Assembly Services
SMT PCB assembly for fine-pitch, BGA and mixed-component boards with stencil, placement, reflow and inspection planning matched to design risk.
What this service solves
A controlled path from requirements to acceptance
Surface-mount quality depends on the complete process window: land pattern, stencil design, paste deposition, placement, thermal profile and inspection all interact.
Best fit for
- Dense digital or mixed-signal assemblies
- Boards using QFN, BGA or other hidden-joint packages
- Prototype through repeat-production requirements
Scope
Typical project deliverables
The exact scope is frozen in the quotation and approved build documentation.
| Deliverable | Control point | Customer output |
|---|---|---|
| 01 · Stencil and paste-process review | Confirmed before material commitment | Approved assumptions and responsibilities |
| 02 · Programmed placement and polarity control | Confirmed before material commitment | Approved assumptions and responsibilities |
| 03 · Thermal-profile planning | Controlled during manufacturing | Repeatable production instruction |
| 04 · SPI/AOI/X-ray allocation by component risk | Controlled during manufacturing | Repeatable production instruction |
| 05 · First-article confirmation | Verified before release | Inspection, test or shipment evidence by scope |
| 06 · Defect and rework records by agreement | Verified before release | Inspection, test or shipment evidence by scope |
Resolve SMT build questions before material commitment
Send the actual board and package information, not only the smallest component size. The outcome of review is an agreed scope or a list of open questions; it is not automatic acceptance of the design.
| Review gate | Buyer input | Decision before release |
|---|---|---|
| Data consistency | Same-revision BOM, centroid, drawings and fabrication files | Resolve mismatched reference designators, orientations and top/bottom data |
| Assembly route | Package datasheets, thermal constraints, heights and panel format | Confirm stencil, support, process sequence and feasibility for this design |
| Materials | Turnkey, consigned or hybrid ownership; packaging and handling information | Confirm approved sources, kit condition, shortages and release readiness |
| Inspection and test | Hidden-joint risks, test access and functional pass/fail requirements | Agree inspection methods, functional-test inputs and remaining coverage gaps |
| Pilot and repeat order | First-article approval and revision-change rules | Confirm what is retained and what must be reviewed again for the next batch |
For customer-supplied parts, use the consigned kit responsibility checklist. For shipment approval, define the project quality plan. Mixed boards also need a through-hole process review.
Start with your actual project
SMT assembly feasibility review
Use the enquiry form to describe the decision you need help with. We select the relevant project context; you remain in control of the details.
- BOM, package details and top/bottom assembly drawings
- Centroid, polarity, panel and handling constraints
- Inspection scope, functional-test needs and quantities
Package support, equipment fit and inspection coverage are confirmed for the complete design, not a generic minimum-pitch claim.
Request this reviewResolve the SMT release blockers before scheduling
An assembly slot alone does not establish a shipment date. Use the open issue to choose the next review, then agree the actual scope with the build team.
| Open decision | Agree before release | Next reading |
|---|---|---|
| The material kit is incomplete | List missing or short items, identify the owner and agree whether a partial kit can enter the release process. | Review material and approval cutoffs |
| A footprint-compatible replacement is proposed | Compare electrical, thermal, mechanical and process differences before written approval. Pin compatibility alone is not qualification. | Use the component substitution checklist |
| The inspection evidence is unclear | Specify visible and hidden-joint coverage, sampling, pass limits and records. Inspection does not establish complete product function. | Compare inspection and functional test coverage |
Use a non-confidential brief to identify open questions. Final feasibility, price and delivery depend on the approved project requirements.
SMT assembly review inputs for mixed packages
| Design feature | Information to supply | Question to resolve |
|---|---|---|
| Fine pitch / bottom-terminated parts | Package datasheets, land patterns and orientation | Stencil, placement and inspection feasibility |
| Large thermal masses | Copper distribution and heat-sensitive components | A compatible reflow process window |
| Double-sided assembly | Top/bottom drawings and component heights | Sequence, support and handling restrictions |
| Panel and board edges | Fiducials, tooling, rails and keep-outs | Machine handling and depanelization clearance |
State the actual package names and pitches in an RFQ. Feasibility is confirmed for the complete board, not inferred from a single minimum-pitch claim.
Workflow
How a build moves forward
- 01
Qualification
Confirm product stage, quantities and commercial fit.
- 02
File review
Identify missing data and manufacturability conflicts.
- 03
Quotation
Separate material, fabrication, assembly, test and logistics assumptions.
- 04
Approval
Freeze revisions, alternates and acceptance criteria.
- 05
Build & validation
Manufacture against the approved package and record agreed results.
Before release
Issues to resolve with the build team
Record an owner and an agreed resolution for any issue that applies to your design.
- Incorrect land patterns
- Insufficient thermal relief
- Poor fiducial or panel design
- Hidden-joint packages without suitable inspection
Buyer questions
Frequently asked questions
Can BGA and QFN components be assembled?
Package support must be confirmed against pitch, board design, equipment limits and the available X-ray inspection plan.
Is AOI enough for every SMT board?
No. AOI cannot fully inspect hidden joints under packages such as BGA. Inspection should be selected according to failure risk and joint visibility.
Why is stencil review important?
Aperture design and stencil thickness influence solder volume, bridging, opens and voiding, especially when a board mixes very small and large components.
Next step
Ready for a build review?
Share your project stage, quantity and target date. We will confirm the files, process and testing information needed for an accurate quotation.