Issue link: https://iconnect007.uberflip.com/i/1508761
70 SMT007 MAGAZINE I OCTOBER 2023 ate reliable solder joints. Unlike other stages where technologies like solder paste inspec- tion (SPI) and automated optical inspection (AOI) use high-resolution cameras to inspect the print of solder paste and placement of com- ponents, reflow soldering inspection presents a different technological challenge. Employing similar camera-based inspection methods dur- ing the reflow process is cost-prohibitive and technically challenging. While AOI can inspect solder joints aer the reflow oven, it does not directly inspect the reflow process and confirm that the proper reflow profile was achieved. The Role of Temperature Profiling To ensure the integrity of the reflow solder- ing process, the industry relies on temperature profiling. is involves measuring and record- ing the temperature profile that the PCB, sol- der paste, and components experience as they pass through the reflow oven. is temperature profile directly impacts the quality of solder joints and the overall reliability of the PCBA. Traditionally, temperature profiling has been a manual operation that requires human inter- vention and production line downtime. Engi- neers use temperature dataloggers and ther- mocouples attached to a test board to mea- sure the temperature profile. is data helps configure and verify the oven's settings for the correct temperature profile and proper sol- dering. But unlike SPI and AOI, it is a static, manual methodology that only gives an infre- quent spot check and is error prone. Let's first discuss the value of SPI and AOI, and then how that translates to the value of reflow pro- cess inspection. The Vital Role of SPI and AOI SPI and AOI systems are not only essen- tial for inspecting and ensuring the quality of PCBAs but also play a significant role in closed-loop feedback and control mechanisms that enhance the accuracy and efficiency of the manufacturing process. Solder Paste Inspection (SPI) SPI systems employ advanced optical tech- nologies to inspect the solder paste printing process, providing real-time feedback and con-