Significance of functional circuit testing of PCBs

PCB manufacturing is a complex process involving multiple steps. Each step plays a critical role in the success of the final assembly. Testing is a step that plays an important role in the success of any PCB manufacturing. The main purpose of testing is to determine whether the design meets its specifications, find out how it will perform under different conditions, and verify its robustness to the environment. There are several test methods available today to help ensure that the board is free of faults before delivery to the customer. Of the several types used in the PCB manufacturing industry, the most common is functional circuit test (FCT). Let's learn more about the tests in this post.

What is functional circuit testing?

A functional circuit test (FCT) is a test that basically checks the functional and electrical performance of the entire circuit. Testing ensures that all components in the board work together and that there are no errors during operation. During this test, the manufacturer also ensures that there are no shorts or opens in the traces, and then makes a pass or fail decision on the finished PCB. Therefore, FCT is one of the important tests to ensure that the board functions optimally as intended.

Advantages of FCT

FCT is a powerful and effective way to analyze performance and gain important insights into board behavior. The testing program also allows problems to be identified before the prototype is actually built, reducing manufacturing costs. Additional benefits associated with functional circuit testing include:

Due to physical defects on the PCB, such as cracks, pinholes, missing components, lack of solder mask, etc., some PCBs may not meet their specified performance requirements. FCT helps to detect such errors.

This test helps to verify that each component on the board is truly functioning without crosstalk, impedance issues, or excessive power dissipation.

Circuit testing must also be able to check that components are properly soldered. Therefore, testing ensures that the PCB is functioning as designed and will not cause any problems later on. Overall, FCT prevents defective products in production, which can be costly.

This test provides the most comprehensive view of signal behavior such as signal distortion, incorrect voltage/current and power integrity, as well as finding incorrect component values and finding parametric faults.

Through a combination of connecting cables, test probes and test software, the technology can also trigger detailed root cause analysis.