What is a PCB Flying Probe Test and How Does it Work?

Advantages

• The main advantage of this test is the less costly process to test boards and circuits. Since probes can easily be free, they reach points of the board without configuring them. It reduces time and labor costs for testing and makes low-cost tests.
• Flying probe tests provide accurate results. The probe has features to measure the electrical parameters of the board with accurate values. It is important to make sure that the board fulfills certain design needs.
• This test is a high-speed test. The probe can move fast over the board, helping the test to finish in a short time. It is best when time is important, like products that have to be delivered in a short time.
• It is a flexible test. Probes can be programmed to move in different configurations to help test different boards. It makes sense to test different products with the same test.
• This test is safe to perform and prevents making contact with any other components. It reduces the chances of any damage that can result from faulty circuit boards.

Disadvantages

• The flying probe testing does not power up the circuit, so it does not get the real structure that ICT provides.
• The flying probe does not have features to inspect the ball grid array. Since the probe needed access points for connection to components.
• It is a high-cost test; normally prices are not high but higher than other tests like AOI.
• This test needed the setup of a test probe and other instruments, which is difficult when testing a larger number of boards in a short time. which can be time-consuming. It can be difficult when testing a larger number of boards in a short time.
• This test also has limited flexibility. This teIt needed special instruments and was not flexible like others. It sizes, as issues arise when testing boards with different other. ns and sizes, as test probes can be needed to set with each other.

Applications of PCB Flying Probe Test

This test has many applications due to its flexible nature and easy testing process. Some main applications are

• This test is normally used for testing PCB boards in the electronics industry. Their flexibility makes them best to use for different PCB testing procedures. like prototype development to small and medium production runs.
• The flying probe test system comes with both in-circuit tests and functional boards (FCT) to make sure of the quality and accuracy of the test and the connections.

In-Circuit Testing

In this test, the connections and functions of individual components of boards are checked, like resistors, capacitors, and integrated circuits. It helps to find manufacturing faults, like open circuits, short circuits, and component misalignments that affect board working.

Functional Testing

This test checks the overall operation of the assembled board by simulating working in real-world conditions. It can be testing the power supply, quality of signal and communication interfaces, and checking accurate operations of embedded software.

The main benefit of the flying probe test system for board testing is the feature to handle different board designs and testing needs without needing the required testing fixtures.

How Does Flying Probe Testing Work?

Some steps involved in flying probe tests are explained here.

1. Load PCB

• In this first step board is configured on the testing platform with accuracy

2. Optically Align Board

For testing the board optical camera is aligned on the board

3. Import Test Program

Test data is imported for CAD

4. Probe Test Points

Probes touch on different options to find the testing nodes

5. Perform Electrical Tests

Tester started and measured on the base of programmed tests.

6. Move Probes

Change the position of probes to cover all nodes

7. Repeat Tests

Steps four to six are repeated to tell verification is completed.

8. Display Results

Now configure the results of this test about finding the faults

Flying Probe Testing vs. ICT Testing

• ICT testing uses certain test fixtures with many spring-loaded probes and flying probe testing uses movable robotic probes.
• ICT testing is best for boards having easily accessible test points and flying probe testing can handle more designs with buried or hard-to-reach components.
• ICT has comprehensive coverage and finds different faults like signal quality issues, flying probe tests have high flexibility for PCB designs that have limitations for some test coverage areas.
• ICT testing is a high-speed operation as it does many tests with the use of many probes and flying probe tests are performed in sequence and slow process.
• ICT tests need development test fixtures that can be time and flying probe testing is fast since it is not based on dedicated fixtures.
• Flying probe tests can perform both electrical connectivity and function features of the board and ICT testing based on electrical integrity.

Process Flow for a Flying Probe Test

Test Program

The process started to make a flying probe testing program. This program provides direction for probes for assessing the board, defining the test type, the voltage measured, and the testing points’ position.

Set  Probe

During the test program at position test probes are configured on point. These probes are configured with a platform that helps ot move over the x, y, and z axes to make sure the correct position over the required testing point on board

Program applications

Over getting accurate position test program is applied. Probe makes connection with board testing points and uses requried voltage levels. Programs measure important electrical features of test points like capacitance, current, resistance, and inductance.

Result

Now configure the result and check that it is according to requirements

Circuit Board Testers

Here commonly used circuit board testers, are listed

• In-Circuit Testers (ICT):
• Flying Probe Testers
• Automated Optical Inspection (AOI) System
• X-ray Inspection Systems
• Functional Testers

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• Types of PCB Board
• Printed Circuit Board (PCB) Materials
• Double Sided PCB Board, Construction, Working, Types & Applications
• Single Sided PCB Board, Construction, Working, Features & Applications
• How to Get High Quality and Low Cost PCB Board
• What is Polyimide PCB Board