All you need to know about printed circuit board assembly testing

All you need to know about printed circuit board assembly testing

Table of Contents

What is PCBA testing?

What is PCBA testing

When a printed circuit board containing electronic components is tested, its electrical conductivity is identified using input and output values, this is called PCBA testing. In the Printed Circuit Board Assembly item test, there are numerical relationships between various test points, such as voltage and current. Professional test tools or a manually operated multi-meter must be used to identify the test points to determine whether the actual Printed Circuit Board Assembly board satisfies the design specifications.

Printed circuit board assembly testing is a crucial step in ensuring the quality of production and delivery. Any Printed Circuit Board Assembly manufacturer should follow printed circuit board assembly testing guidelines and follow the customer’s test strategy when conducting tests.

Why PCBA testing is important?

One of the most crucial electrical components utilized in the current era is a printed circuit board (PCB). There isn’t a single electronic device that we can think of that doesn’t require a Printed Circuit Board. But first, we must go through the process of assembling the PCBs before we can implement the Printed Circuit Board’s properties. The Printed Circuit Board Assembly (PCBA) must also be tested before a Printed Circuit Board can be successfully assembled. This is one of the last and most important procedures.

This process is crucial since it makes sure the manufacturers don’t get defective Printed Circuit Board assemblies.  If not tested, some PCBA products may have various failures due to poor quality, bringing manufacturers various issues such as free warranties, return refunds, and even compensation. Therefore, PCBA testing can also save time and money in the long run.

The producers choose the printed circuit board assembly testing method that will be most advantageous to them from a variety of approaches. However, we will discuss the most well-known techniques that are employed by global manufacturers for printed circuit board assembly testing. The following are some common techniques for printed circuit board assembly testing:

1.In-Circuit Testing Method


3.Flying Probe Testing

Flying Probe Testing

4.Automated X-Ray Inspection

Automated X-Ray Inspection

PCBA testing equipment

Every Printed Circuit Board should undergo a thorough examination to look for open circuits and shorts as well as to verify that the integrated components have the expected values. Some of the equipment commonly used in PCBA test equipment are:

  1. Vertical architecture, with automatic “stretch” of the panel
  2. Automatic and complete test program creation
    • External BOM import capability
    • Open/Short test
    • Electric barcode reading
    • Passive and active components
    • Data storage for traceability
  3. Automatic panel loading/unloading module

The processes of PCBA testing

The following steps are commonly included in the printed circuit board assembling (PCBA) process.

The processes of PCBA testing

Perform some inspection and testing procedures on the Printed Circuit Board Assembly after soldering the components onto the Printed Circuit Board. The device under test, or DUT, is the name given to this circuit board. Each of these steps will be briefly described below:

Automated Optical Inspection

Computer vision is used in automated optical inspection stations to check that all elements are populated and that the solder joints appear to be in excellent condition after a camera takes pictures of the circuit board.

Automated X-Ray Inspection

Similar to AOI is automated X-ray inspection (AOX). However, it processes X-Ray images using computer vision rather than optical images. By examining X-Ray images, the test can verify all of the solder connections on the board, including solder joints tucked beneath a component. Ball grid array (BGA) component attachment accuracy can be verified with AOX test stations for each Printed Circuit Board product.

Flying Probe and In-Circuit Testing

The testing process for a DUT is the same for Flying Probe and In-Circuit Testing (ICT). Pogo pins are used in these test procedures to measure resistance, capacitance, and other important properties between test spots on the product.

Functional Testing

A functional test (FCT) likewise makes use of a Bed-of-Nails fixture, but instead of evaluating the electrical connectivity between various nets, it verifies that the DUT functions as predicted. It can be verifying the firmware’s functionality, for instance. The verification of the hardware’s functionality depends on this information.

Common PCBA defects

Common PCBA defects

There are many different potential causes of soldering faults, from operator error to environmental factors. The most common of these defects are:

  • Opens
  • Component shifting
  • Excessive solder
  • Lifted pads
  • Cold joints
  • Webbing and splashes
  • Solder bridges

How do you choose the PCBA testing methods?

Testing is an important stage in PCBA design and production. Designers and manufacturers can choose and use appropriate methods or entrust special laboratories for inspection. Testing should ensure the safety and correct functionality of the PCB. Figuring out which PCB testing is right for you can be a challenge; there are certainly many ways! Your technician will know which tests are more appropriate, so check with them often.

Whatever approach you choose, printed circuit board assembly testing is a crucial stage in the design process that may save your company a lot of time and money by catching flaws before they have an impact on production.

The future of PCBA test technology

The future of PCBA test technology

It is difficult to predict which PCBA testing technology will succeed or be eliminated in the future, and each testing technology has its own advantages and disadvantages. Judging from the development trend in recent years, the combination of a variety of test technologies, such as the combination of AXI and ICT testing, will soon become the preferred method for PCBA testing.

Due to the increasing complexity of current circuit boards, traditional circuit contact testing is greatly limited. Defects are difficult to diagnose through ICT testing and functional testing. With the increasing density of most complex circuit boards, traditional test methods can only increase the number of test contacts in an in-circuit tester. However, as the number of contacts increases, so does the cost of test programming and bed of needle fixtures. Some new and more advantageous PCBA test methods will also be applied.


IBE has been focusing on PCB manufacturing and assembly for several years with circuit board test qualifications and complete test items. IBE provides functional testing (FCT) and other testings for PCB assembly orders. We can test your products according to your needs and applications, helping you quickly test the products accurately at fair prices. Get a quote now!

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