IPC International Community magazine an association member publication
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C O M M U N I T Y M A G A Z I N E 7 0 S U M M E R 2 0 2 5 process to be optimised. This essentially gives us three areas to optimise: • Fluxing • The preheating process • Soldering itself We aim to generate a process that achieves the high- est grade of soldered joints possible. Fluxing optimis- ation necessitates the selection of which application method suits the product best (ultrasonic spray or the more precise drop-jet precision droplet dispenser), pathing of the fluxer for speed of application, and the selection of flux itself. Flux selection involves balancing activity, solids content, and presence of halides, depen- dent upon product requirements. Post-process clean- ing and the risks of electrochemical migration must be considered to extend the lifetime of the product. When considering preheating, the copper content of the PCB and the thermal capacities of the components and their temperature limits must be balanced. The board and its components should reach the target temperature (to achieve flux activation and ensure proper solder wet- ting) within the required cycle time without damage. Using closed-loop control with a pyrometer allows for monitor- ing the surface temperatures of sensitive components. Soldering itself involves programming bath positions and vectoring to quickly join components without damaging them. The choice of solder is another point for optimisation; the liquid and solid properties must be explored for proper control during deposition, wet- ting to the component, and final joint strength. The performance of low-temperature solders is advanc- ing quickly, but their operating environment must be considered, and we must ask whether they meet the thermal and mechanical requirements. Lower-cost manufacturing does not justify failures in the field due to poorly chosen materials. Conclusion Sustainability presents rich opportunities for the elec- tronics industry. As adaption drivers increase, there will undoubtedly be challenges, but industry collaboration will increase our toolset for adapting to changes. Man- ufacturing processes such as selective soldering are extremely tunable to allow for more sustainable joining of components to PCBs. B I T S & B Y T E S Sustainability