PCB assembly capability describes the ability to populate and verify a specified board. It differs from bare-board fabrication capability: microvia drilling and laminate bonding belong to fabrication, while component placement and soldering belong to assembly. A supplier may offer both, but each needs review.
Start with the actual component list
Identify the smallest and largest packages, hidden joints, tall components, connectors and any parts requiring special handling. Include both board sides and the intended panel format. A headline minimum component size does not establish suitability for the whole assembly.
TI’s packaging application-note collection provides package-specific assembly references. Use the documentation for the selected devices when discussing lands, process constraints and inspection needs with the assembler.
Review each process step
| Step | Capability question |
|---|---|
| Material handling | Can supplied components be identified, stored and fed correctly? |
| Paste application | Does the stencil and support arrangement suit the lands? |
| Placement | Can all packages and orientations be handled? |
| Soldering | Does the process suit components, board and mixed technologies? |
| Inspection | How are visible and hidden joints assessed? |
| Test and rework | Can failures be diagnosed and corrected under an agreed procedure? |
Separate inspection from functional verification
Optical inspection, X-ray inspection and electrical testing reveal different kinds of information. Do not assume that a list of machines means every board receives every check or that one method proves the complete product function.
Ask what is included in the quote, what sampling or coverage applies and which records are available. If functional testing is needed, provide a procedure, limits and required interfaces. Programming should also identify the approved firmware revision and verification method.
Review accessibility after all components are installed. A test point that is visible on an empty board may be blocked by a connector, heatsink or cable in the completed assembly. The fixture concept and assembly sequence should account for the actual populated geometry, including the underside.
Use a representative assembly trial
- Review the BOM and package documentation.
- Resolve land, paste and panel questions.
- Agree process and acceptance requirements.
- Build representative boards with the intended materials.
- Inspect and test the relevant features.
- Record findings and update the released instructions.
Include the difficult component combinations in the trial. A successful board with only large passive parts does not establish readiness for a densely populated assembly with hidden joints and heat-sensitive components.
The assembly capability checklist supports an inquiry, and the inspection guide helps define the evidence needed to accept the finished assemblies.
Move from reading to a build-ready project
Use the fabrication and assembly checklists to prepare drawings, production files and test requirements.
Open the DFM checklist