PCB & PCBA Testing
Use the right check at the right production stage. FLJ combines board and assembly inspection with project-specific electrical and functional testing to help verify your build before delivery.
A test plan follows the product through manufacturing
PCB and PCBA testing covers different stages: checking the bare circuit board, inspecting assembly processes, and measuring the populated board or finished product against an agreed procedure.
Each method answers a different question. Electrical testing checks bare-board connections. Optical and X-ray inspection examine manufacturing features. In-circuit testing can measure accessible circuit elements, while functional testing exercises the intended operation.
We review the design, component packages and production goals to build a useful plan. If the test procedure is still developing, send the information you have. Our team can discuss what can be checked now and what needs additional access, tooling or product instructions.
Inspection and test methods by production stage
These methods are complementary. AOI does not see every hidden joint, and a visual pass does not prove product function. The quoted plan identifies the applicable checks rather than treating every method as automatically included on every order.
| Method | Production stage | What it helps verify |
|---|---|---|
| Bare PCB electrical test | Before assembly | Continuity within nets and isolation between nets |
| SPI | After solder paste printing | Paste deposit characteristics before placement |
| AOI | Assembly inspection | Visible component and solder features against the programmed criteria |
| X-ray | Hidden-joint inspection | Selected internal solder features, including BGA joints |
| ICT | Populated-board electrical check | Accessible circuit measurements using the agreed program and fixture |
| Functional testing | Powered assembled board or product | Application behavior against a defined procedure |
| Final inspection | Before packing | Agreed workmanship, identity, completeness and packaging checks |
Catch assembly issues while the process is still accessible
SPI helps assess solder paste deposits before the components are placed. AOI then checks visible assembly features using the programmed board information. These process checks can direct attention to a printing or placement issue while there is a practical opportunity to investigate it.
X-ray inspection is useful when the joint cannot be judged from the outside, such as under a BGA package. We review package geometry and the inspection objective when defining the scope. The method, image interpretation and acceptance criteria need to match the feature being examined.
First-article review connects the assembly drawing, BOM, component orientation and inspection results before the production approach is repeated across the batch.
Define what the assembled board should do
A useful functional test describes observable behavior, not simply that the board should work.
Start with the operations that matter to your product: power-up, current draw, communication, inputs and outputs, calibration or firmware response. A schematic, procedure, firmware file or known-good sample can help establish the sequence. You can send whichever of these is already available.
ICT and functional testing serve different purposes. ICT depends on access and a suitable measurement program; functional testing may use external connectors, software and dedicated equipment to exercise the application. We review the intended coverage and the effort needed for each.
Programming, calibration and powered testing should use the agreed firmware revision and operating conditions. If your team is still deciding the pass/fail limits, we can discuss how to make them measurable for the production process.
Plan fixtures, access and records early
Test points and accessible connectors can make repeat-production verification easier. A stable design may justify a dedicated fixture, while an early prototype may use a more flexible setup. We review the design stage, quantity and expected repeat builds when discussing tooling.
Tell us which results need to accompany the shipment. Possible discussions include first-article observations, specified measurement results, test status and serial-number-linked records. The order defines what is recorded and delivered, so your receiving team knows what to expect.
Workmanship acceptance, quality-system certification and product market certification are separate subjects. A production inspection or functional test is valuable evidence for the build, but it does not by itself establish regulatory certification for the finished equipment.
Specialized board and assembly verification
If your supplier review or product qualification needs an additional test, tell us the question it needs to answer. Our team will discuss a suitable arrangement and reporting scope.
| Verification request | Review focus | How we define it |
|---|---|---|
| Microsection review | Internal connection, plating or construction questions | Discuss section location, sample scope and findings needed |
| Solderability checks | Exposed pad finish and intended assembly process | Agree the method, sample and reporting requirements |
| Thermal or environmental evaluation | Defined product operating or qualification question | Review temperature, duration, cycles and acceptance with the test scope |
| Impedance verification | Target, coupon and measurement arrangement | Connect the result with the approved stackup |
| Functional verification | Power, firmware, interfaces and outputs | Develop clear operating checks and result records |
Specialized requests are reviewed for equipment, fixtures and any external test arrangement. Listing a test topic does not mean every order includes it.
Build the test scope with FLJ
Send the existing board files, BOM and any test notes or concerns. For a bare-board order we focus on fabrication verification; for PCBA we add the relevant assembly and product checks. Missing details can be discussed after the initial review.
We can then explain the proposed sequence, project-specific tooling and documentation options. For repeat orders, the approved revision and any changes help keep the test scope aligned with the product you intend to receive.
Frequently asked questions
Do I need every inspection method for my PCBA?
No. The useful combination depends on the design, packages, access and application. We review those details and agree the scope with you.
Can you help if we do not have a functional test procedure yet?
Yes. Send the schematic, product description and any firmware or sample information available. We can discuss a practical procedure and the additional inputs needed.
Does AOI replace X-ray inspection?
No. AOI checks visible features. X-ray can examine selected hidden joints, so the methods address different inspection needs.
Can test results be linked to individual boards?
Share your traceability needs during review. We can discuss identifiers, the measurement records required and the agreed deliverable format for the project.
Let’s review your next build
Send your available board files, drawings or project questions. Our team will review the information and follow up with you about the next step.