The inspection can often remind you that there are too many variables in your assembly process. Even if your manufacturing process can achieve continuous zero defect production, a certain form of inspection or monitoring is necessary for ensuring the desired quality level. Surface mount assembly is a series of very complex events with a large number of individual actions. Our trick is to build a balanced inspection and monitering strategy, without a 100% check. This article will discuss the inspection methods, technology and manual inspection tools, and review the automatic inspection tools and the use of inspection results (the number and type of defects) to improve the quality of process and products.

Inspection is a product centric activity, and monitoring is a process centric activity. Both are needed for a quality plan, but the long-term goal should be a little less product inspection and a little more process monitoring. Product inspection is passive (defect has happened), and process monitoring is active (defect can be prevented). Obviously, prevention is more valuable than passive reaction to existing defects.

The inspection is actually a screening process, because it attempts to find unacceptable products to repair it. The fact is very clear that a lot of inspection does not necessarily improve or guarantee the quality of the product. "Don't expect large numbers of checks," said Deming's third point at Deming. Deming stressed that a strong process should focus on the establishment of statistical process monitoring is stable and repeatable, and the check is not a big volume. Inspection is a subjective activity, and even if a considerable degree of training, it is also a difficult task. In many cases, you can call a group of inspectors to evaluate a welding point, but get several different opinions.

Operator fatigue is why 100% checks usually fail to find the cause of every manufacturing defect. In addition, this is a high cost, value - free operation. It rarely meets the desired goal of higher product quality and customer satisfaction.