Part Number: VAIL6191C1
Application: SAIC Car Charger Main Control Board
Power Failure Warning Function
New development projects require more complex, larger PCBAs and tighter packaging. These requirements challenge our ability to build and test these units. Furthermore, larger circuit boards with smaller components and higher node counts may continue. For example, a design that is currently drawing a circuit board diagram has about 116,000 nodes, more than 5,100 components, and more than 37,800 solder joints that require testing or verification. This unit also has BGA on the top and bottom surfaces, and the BGA is next to each other. Using a traditional needle bed to test a board of this size and complexity, a method of ICT is impossible.
In the manufacturing process, especially in testing, the ever-increasing complexity and density of PCBA is not a new issue. Realizing that increasing the number of test pins in the ICT test fixture is not the way to go, we began to observe alternative circuit verification methods. Seeing the number of non-contact probes per million, we found that at 5000 nodes, many of the errors found (less than 31) may be due to probe contact problems rather than actual manufacturing defects (Table 1). Therefore, we set out to reduce the number of test pins, rather than increase them. Nevertheless, the quality of our manufacturing process is evaluated to the entire PCBA. We decided that the combination of traditional ICT and X-ray layering is a feasible solution.
