QPE Blog: PCB assembly testing: checking that your product is ready

Manufacturing a PCB assembly is only part of preparing it for use. Before it moves to the next stage of the supply chain, testing can help verify its electrical connections and assess whether it performs as intended.

The appropriate testing approach depends on the design, application and customer requirements. A simple assembly may need different checks from a complex board with several operating functions.

At QPE, we work with customers to establish a testing strategy suited to each project, with capabilities including flying probe, functional and continuity testing, alongside customer-specific procedures.

Inspection and testing provide different information

Inspection examines the physical assembly, helping identify issues such as misplaced components or visible soldering defects.

Testing provides information about electrical connections or the behaviour of the assembly under defined conditions. A board can appear correctly assembled but still have an electrical issue, which is why inspection and testing can complement each other.

The combination used should reflect what needs to be verified before the product is released.

Choosing the appropriate tests

Different methods address different questions:

• Flying probe testing uses moving probes to access points on the PCB and perform programmed electrical checks. The checks available depend on the board’s design, access and test programme.

• Continuity testing checks whether intended electrical paths are connected. Appropriate checks can also help identify unintended connections.

• Functional testing assesses specified operations by applying power, signals or other inputs and checking the assembly’s response.

• Customer-specific procedures provide checks against defined product requirements and acceptance criteria.

  
  

These methods may be used individually or together. The aim is to select checks that provide useful evidence against the agreed requirements.

Planning testing before production

Considering testing early helps clarify what information, access and equipment will be needed.

Depending on the project, this may include accessible test points, connectors, fixtures, software and documented procedures. Agreeing the expected results and pass criteria also gives the manufacturing team a clear basis for assessing each assembly.

Resolving these requirements before production helps avoid delays when completed boards reach the testing stage.

What this means for customers

A suitable testing strategy provides additional confidence that an assembly meets the requirements covered by the agreed tests.

It can also help identify issues while the product is still within the manufacturing process, allowing investigation before it progresses to integration or use.

At QPE, testing forms part of a wider approach to quality, alongside controlled assembly processes and appropriate inspection. We work with customers to define checks that reflect the needs of their product.

Planning a new build or reviewing your test requirements? Contact QPE to discuss a testing approach for your assemblies.

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