Flying Probe vs. ICT: Which is the Best PCB Testing Method?

Flying Probe vs. ICT circuit testers guide. Make no mistake dismissing circuit testing in PCB assembly as it is one of the most critical aspects that guarantee quality. 

Today, we require high-performance circuit boards since electronic components dominate every aspect of our lives.

 Therefore, any assembly defect could prove costly in the bigger picture. Primarily some devices are critical to fields such as the medical and treatment realm. 

But while we have a range of testing techniques, the two we’ll cover in this guide are among the most popular ones. 

What makes them famous? Let us see below. 

What Is Flying Probe Testing?

It is one of the most straightforward PCB functional testing modes that utilize fixed or mobile probes (testers) on the top and bottom parts of the circuit board to detect defects. It is a common testing technique that many companies employ for in-house defect testing operations. 

Features of Flying Probe Testing

Computer circuit board assembly and robotic, automatic flying test probe. 

Computer circuit board assembly and robotic, automatic flying test probe. 

The underlying characteristic of the testing probes is that they are, in principle, high-precision needles. 

Thus, they can unearth issues on the PCB’s electrical networks that are undetectable to the naked eye. 

They come in handy in low-volume order scenarios, whereby they are famous for their lack of sophistication. 

Also, they are excellent in testing fundamentally because they don’t have any specificity in their application.

 You can add them to any production line, and they’ll do the job. 

But using them is a slower process than the other technique we’ll discuss in the next section.

 You can apply the flying probe testing technique in any of the following scenarios: 

  • Testing ICs
  • Checking the functionality of electrical components on the circuit boards
  • Verifying if there are defects in solder connections 

Electronic contract manufacturers who apply the method conduct the testing after completing the surface mounting of all parts on the PCB.

 It is cardinal to eliminate the testing process after shipping the parts to the buyer. 

How Does Flying Probe Testing Work?

Flying probe test - automation machine equipment.

Flying probe test – automation machine equipment.

Board testing using this technique begins by creating a software program highlighting the actions the custom testing fixtures should undertake.

 Part of this program includes Gerber files of the circuit board. 

It allows the probe to access every area of the circuit under test. 

Next, the electronic contract manufacturer uploads the program onto the flying probe testing device. 

This software has probe testing instructions on what the system should check. 

The manufacturer then delivers the circuit boards for testing via a conveyor belt system. 

Finally, if the manufacturing defect analysis detects a problem, it outputs it onto a computer for rectification. 

Advantages of Flying Probe Tests

Automation machine equipment for quality testing of printed circuit boards. 

Automation machine equipment for quality testing of printed circuit boards. 

  • It is the go-to technique for manufacturers looking to perform quick tests on PCB boards. 
  • Also, if conducted appropriately, it guarantees accurate and high-quality tests thanks to its capacity to access circuit nodes. 
  • It’s straightforward to perform, given that it doesn’t compel the manufacturer to create test points before manufacturing. 
  • Fourthly, the method is superb in testing LED components and other parts that are pretty intricate. 
  • The technique also allows board verification of Field Programmable Gate Arrays (FPGAs).
  • Moreover, it guarantees high volume testing throughput thanks to the simplicity of the procedure. 
  • The per unit costs for the technique are relatively low, and it is effective in testing the entire PCB and the individual components. 
  • Given its application feasibility to all PCBs, it is the most flexible testing method. 
  • With the method, you can also perform tests such as component polarity testing thanks to the high-level cameras it possesses. 
  • Finally, custom tooling is not mandatory with this testing method making it straightforward to perform. 

Disadvantages of Flying Probe Tests

  • The development time for the testing blueprint can be extensive, which can significantly delay the production lead times. 
  • Moreover, while the per-unit costs are affordable, the method comes with high upfront costs. It is because manufacturers must invest in expensive programming tools that are cardinal to precision tests. 
  • It is not ideal for performing nonelectrical components testing, nor does it apply to testing solder connectors in circuits. 
  • Lastly, it is unsuitable for high-volume testing; hence the development lead time when dealing with numerous components is relatively low. 

What Is In-Circuit Testing?

Integrated circuit testing. 

Integrated circuit testing. 

It is a unique testing method that applies a bed of nail fixtures to perform defect testing in intricate PCB parts like nodes. 

It’s a more effective and faster testing method than the flying probe test methods, given that it can also apply to digital circuits. 

So what primarily differentiates it from the flying probe test technique?

 First, applying this method necessitates designing and creating a custom fixture to be used in the testing process. 

Also, it is more suited to testing sophisticated circuits. 

Advantages of In-circuit Testing

  • It is the ultimate testing method for quick tests, as it’s relatively faster than flying probe testing. 
  • Also, like a flying probe, it is suited for testing individual parts and LED components. It also enables complex testing methods such as logic functionality and BTC component soldering. 
  • The technique also checks individual component features like tolerance, capacitance, and resistance. 
  • Finally, an in-circuit test is incredibly effective in testing for shorts. 

Disadvantages of In-circuit Testing

  • It has an extensive development lead time, high upfront costs, and custom tooling is mandatory. 
  • Also, it doesn’t test non-electrical components.

Flying Probe vs. ICT: Which Works Better?

Multi-purpose flying probe system. 

Multi-purpose flying probe system. 

Below are the factors that determine the best technique for every scenario, given that each has its fair share of upsides and limitations. 

Product Design

How complex is the overall design of your PCB? If you’re testing exterior parts such as component pads, the flying probe method will be up to the task. 

However, ICT is more suited to intricate designs. 

Lead Development Time

Choose the FPT technique if you’re looking to test components quickly, primarily because this method doesn’t require making custom fixtures. 

For ICT, you may have to wait up to a month or more as you develop custom tooling components. 

Expected Volumes

ICT is arguably the best option if you’re capitalizing on production volumes, as it’s pretty fast. 

The initial investment to set up the systems could be relatively high and time-consuming, but it’s worth every penny. 

In contrast, FPT is slower and is thus best suited to testing small prototype batches. 


There’s no outright cheaper technique of the two but programming FPT systems is easy and thus less pricey. 

But in terms of per unit costs after setting up everything, ICT comes cheaper than its counterpart. 

Also, given its high throughput, it is the best low-cost option when specializing in high-volume assemblies. 


Effective testing of PCB parts doesn’t have to be sophisticated, and a testimony to this is the simplicity of the techniques we have just covered. 

Nonetheless, contract manufacturers don’t take anything for granted. 

They invest heavily in setting up automated and high-precision systems utilizing either of the techniques to optimize the output PCB performances. 

Thanks for reading to the end, and see you in our next article.