What are the tests for finished PCB production?

1. #PCB testing requires #LCR measurement

LCR measurements are suitable for some simple PCBs. There are very few components on the PCB, no integrated circuits, only some passive components. After the placement is completed, there is no need to renovate, just use LCR directly on the components on the PCB. Measure the device and compare it with the #component ratings on the #BOM. If there are no abnormalities, formal production can begin.

2. PCB inspection FAI first article test

#FAI first test systems typically consist of a set of LCR bridges led and integrated by FAI software. Employees use their own #fixtures to measure the first #sample part, and the system will check it with the input #CAD data. The test process software displays the results through graphics or voice, reducing mistests caused by personnel's negligence in searching and saving labor costs.

3.PCB AOI test

#AOI test, this test method is very common in #PCBA processing and is suitable for all PCBA processing. It mainly judges the welding problems of components through the appearance characteristics of the components. It can also check the color of the components and the silk screen integrated circuit. Determine whether the components on the circuit board have incorrect parts.

4. PCB flying probe test

Flying probe testing is usually used for small batch production of some development properties. It has the characteristics of convenient testing, strong program variability, and good versatility. Basically, it can test all types of PCBs, but the testing efficiency is relatively low. The testing time of each board will be very long. It mainly determines whether the total components of the circuit board are short-circuited or not by measuring the resistance between two fixed points. Air welding, wrong parts, etc.

5. PCB X-RAY detection

For some PCBs with hidden solder joints, such as #BGA, #CSP, and #QFN packaged components, #X-ray inspection is required for the first product produced. X-rays are highly penetrating. One of the earliest instruments used in various inspection situations. X-ray fluoroscopic images can show the thickness, shape and quality of solder joints as well as solder joint density. These specific indicators can fully reflect the welding quality of solder joints, including open circuits, short circuits, holes, internal bubbles and tin deficiency, etc., and can be quantitatively analyzed.

6. PCB ICT testing

#ICT testing is typically used on models that have been mass-produced. The test efficiency is high and the manufacturing cost is high. Each type of PCB requires a special fixture. The service life of the fixture is not very long, and the testing cost is relatively high. The testing principle is similar to the flying probe test. It also measures the #resistance between two fixed points to determine whether the components on the circuit have short circuits, empty soldering, wrong components, etc.

7. PCB FCT functional test

#FCT functional testing is usually used on some more complex PCBs. The PCB to be tested must be soldered and passed through some specific fixtures to simulate the real usage scenario of the PCB. In this simulation scenario, after turning on the power, observe whether the PCB can be used normally. This testing method can accurately determine whether the PCB is normal.

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