Method of inspecting the quality of SMT by step

In the SMT processing, if the output of each step are searched and errors are eliminated, good process control can be achieved and the yield of products can also be improved. Therefore, the quality inspection of SMT products is indispensable. Next, Shenzhen SMT processing plant SYS Technology will give you a good explanation.

1. The role of quality testing

It can help SMT processing plants find defects early, so as to prevent defective products from flowing into the next process and reduce the cost of repairs. Find defects in time and deal with them in time to avoid the generation of scrapped products and reduce production costs.

2. The method of quality inspection

I. Visual inspection: use human eyes to directly observe the quality of the SMT PCBA. The main step in SMT production set a visual inspection workstation.

Features: The cost is low, nut the inspection effect is related to the mounting density of the PCB. In the case of low-density placement, the accuracy, reliability, and continuity of the inspection have a lot to do with subjective consciousness. In high-density mounting, the accuracy, reliability, and continuity of the detection results will be reduced, and the detection time will also be longer.

II. AOI inspection: automatic optical inspection, that is, inspection with automatic optical equipment, which is a substitute for visual inspection. AOI inspection process is usually performed after solder paste printing or reflow soldering.

Features: AOI detection system has nothing to do with PCB mounting density, fast detection speed, high precision, high reproducibility, bad detection results are directly displayed graphically on the operating display and marked on the PCB by worker.

3. ICT detection: 

Circuit test, that is, Circuit fault detection with Circuit tester. ICT testing procedures are usually set up after PCB assembly is completed.

Features: The fault diagnosis ability is strong. Welding defects such as bridging, empty welding, pseudo welding, and wire disconnection positions can be directly show at the defective points; welding defects caused by component defects can also be detected.

It is very necessary to inspect the quality of SMT steps, it is an effective way to save costs. A complete quality inspection system is an important standard for measuring product quality.