Flying Probe Testing: The Faster, More Accurate Way to Test

In the realm of PCBA projects, optimizing production schedules is crucial. ICT testing plays a key role in achieving this objective, offering efficient solutions such as bed of nails and flying probes. Both methodologies offer unique advantages and characteristics, and in this article, FS Technology will provide a comprehensive overview of the benefits and applications of flying probe testing.

Flying Probe Test PCB

What is flying probe test

This is a non-intrusive testing technique to verify the electrical connectivity of the PCB. Flying probe test involves the use of small probes that establish connections with the copper traces and pads on the PCB. While this method does not require specialized fixtures or test procedures designed for each individual board, it may not be the most efficient option for high volume PCB assembly due to its slower nature. Here are its features:

  • Flexibility: It is particularly suitable for testing boards with fine-pitch components and complex structures. Its flexible programming and configuration capabilities allow it to adapt to a wide range of PCB designs.
  • Speed: The flying probe test derives its name from the high-speed movement of the probes on the board surface. This results in a fast inspection process that does not require specialized fixtures or programs. However, it is not suitable for large-scale batch projects, as each board must be tested individually. This makes it ideal for PCBA Prototyping.
  • Test Range Limitations: Primarily designed to detect the connectivity of PCBs and perform simple electrical tests. It is not suitable for testing high-speed digital signals, RF signals, and power distribution tests, among other applications.
  • Non-destructive: The flying probe test is a non-contact test method that scans the board surface without the need for physical contact between the probe and the board. This makes it particularly useful for expensive applications such as industrial control PCB and medical PCB, where physical damage to the board would be costly.
  • Early-stage Investment: Requires significant investment in the early stages involves investing in manpower and material resources to complete the preparatory work required for the test. However, this initial investment ensures the accuracy and reliability of the testing process, which can ultimately save time and costs in the long run.

How to ensure the quality of FPT

Testing Process

Flying probe testing works by relying on a probe known as a “flying probe” to move across the surface of the board and scan copper traces and pads to confirm continuity and isolation between them. The motion of the probe is regulated by a computer program that sends commands to move the probe at specific points on the board. 

To perform a flying probe test, the operator first obtains a Bill of Materials (BOM) file which includes a list of all components in the design. They also need the electrical connection details mentioned in the netlist file and data from Computer-Aided Design (CAD) files about the physical layout of components and traces. Using this information, the operator can define the probing locations and desired results for the test.

During the test, the flying probe is moved by a computer program that sends commands to move the probe to specific points on the board. The probe makes contact with the test points and checks for continuity and isolation between them. The results of the test are then analyzed to identify any failures. The test results are presented in a summary of test points and the number of failures, and board graphics showing the test points and their results.


Flying probe testing is a highly reliable and accurate method of testing PCBs, which can detect a range of issues including open circuits (where there is no electrical connection between two points), short circuits (where there is an unintended electrical connection), and capacitance and inductance problems.

However, if any errors do occur during the test, our company takes the following steps to solve the problem:

  • Fault Identification: Review the test location to identify the exact location of the fault.
  • Check Physical Connections: Verify that all components and traces are physically connected and that there are no points of damage or other issues that could be causing the problem.
  • Test Components and Traces: Use advanced tools, such as a multimeter or oscilloscope, to test components and traces to check for faults and ensure that they are functioning correctly.
  • Validate Netlist Files and Test Programs: Checks the netlist files and test programs to ensure that they are correct and that there are no errors or inconsistencies that could be causing the problem.

Is Flying Probe Testing Worth It In PCBA Projects

Flying Probe Test vs. Bed of Needles Test

FeatureFlying Probe TestBed of Needles Test
Type of TestNon-intrusiveIntrusive
Testing MethodAutomatedManual
Equipment UsedFlying probe machineBed of needles fixture
Test AccuracyHighModerate
Test SpeedFastSlow
Test CoverageLimitedFull
Test Point AccessibilityHighLow
Test CostMediumHigh
Operator Skill RequiredLowHigh

Flying Probe Test vs. Functional Test

FeatureFlying Probe TestFunctional Test
Type of TestNon-functional/structuralFunctional
Testing MethodAutomatedManual or automated
Equipment UsedFlying probe machineTest fixtures, oscilloscopes, and other instruments
Test AccuracyHighHigh
Test SpeedFastSlow
Test CoverageLimitedFull
Applicable projectSmall BatchHigh Volume
Test CostMediumHigh

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