Issue link: https://iconnect007.uberflip.com/i/1546933
28 SMT007 MAGAZINE I OCTOBER 2026 We embed sensors at the appropriate positions to gather temperature data along the board path. The principle is consistent with what we now call Industry 4.0, although KIC began monitoring conveyor- ized thermal processes in 1977. The oven's control thermocouples confirm that its zones are control- ling to their setpoints, but they do not show what is happening to the product at the conveyor level. Our patented sensor hardware and software use 30 fixed thermocouple measurement points, together with conveyor speed and product position, to calcu- late the thermal profile each board experienced. The engineer or technician runs that baseline profile in programming mode. As with program- ming SPI, you provide baseline images, and when it's inspecting production boards, it flags deviations. In the reflow process, the baseline is estab- lished with thermocouples attached to the board. Once that data is used to optimize the profile, it programs the inspection system. During produc- tion, the system tracks each board past the embedded sensors and calculates its profile as it exits, including ramp rates, soak times, time above liquidus, and peak temperature. Do these thermocouples pass that information back to the oven controller so the oven can adjust in real time to keep the temperatures right? Is KIC in the control loop, in other words? That's not a straightforward answer, because there's a lot more that influences the profile beyond what we're moni- toring. We can accurately read the situation, but there are other param- eters. We can identify that the profile has changed, but the data alone may not identify the cause. Is it the load? Maybe it's a panel of 8-up engine control- lers on one panel, where it's a bigger board, and they're running a board every eight inches. When the oven is fully loaded, those boards are really pulling heat. We don't want to start adjusting the control loop because of these other influences. Instead, we use a human-in-the- loop approach. When we see a trend moving in the wrong direc- tion, the system alerts the user and provides as much guidance as possible. If necessary, the engi- neer can run an instrumented profile and re-opti- mize the recipe. You're providing the data and process monitoring, but are you leaving the ultimate decision-making to the process engineers to make the appropriate adjustments? We give direction, not just an alarm. Because factors beyond the oven's basic control loop can influence the profile, the process still needs a human in the loop. As the technology improves, more decisions may be integrated into the control loop, but today the best result is notification followed by guidance on where the issue may be. We don't want to hide something by continuing to control the oven when it has nothing to do with adjusting the heat. For example, if reflow time were increasing and an automatic loop responded only by speeding up the conveyor, the assembly could receive insufficient thermal exposure because conveyor speed was not the root cause. There are Many factors influence reflow consistency.