As a relatively mature manufacturing method, outsourcing PCB assembly is entering an era of thin profits. The profit margins for PCBA processing are decreasing, while the quality assurance requirements are increasing. A key requirement in PCBA assembly is consistency and accuracy. Differences need to be controlled, and variations are not allowed. Poor quality in assembly manufacturing can stem from three main aspects: design issues, material problems, and assembly issues. While the first two aspects require preemptive measures to prevent their occurrence, problems during the assembly process, such as missing parts, damaged parts, incorrect parts, and misalignment, can mostly be visually inspected. However, determining soldering quality is challenging with visual inspection alone, and sometimes PCBA deliveries may result in faults like short circuits, board explosions, or malfunctioning functions. According to statistics provided by the China Electronics Quality Analysis Center, soldering defects account for 57% of all assembly defects.
As PCBA boards trend toward miniaturization with smaller components, electronic assembly components are becoming increasingly miniaturized (high-density), leading to solder defects, difficult detection and positioning, poor visibility, poor reparability, and even irreparability, thereby increasing potential failure risks.
Traditional visual inspection controls in the PCBA assembly process alone cannot completely eliminate soldering defects. Automatic X-ray non-destructive testing is also necessary, and it has been widely used in the Yangtze River Delta, Pearl River Delta, and military production, with very good results. However, the significant investment in additional equipment, coupled with the continuously increasing labor costs, has made many small and medium-sized PCB manufacturers overwhelmed. Moreover, with customers’ continuous demands for processing quality, PCB manufacturers with limited capabilities are unable to afford the high costs of additional testing methods.
