Issue link: https://iconnect007.uberflip.com/i/1379105
JUNE 2021 I SMT007 MAGAZINE 43 Discussion on possible solutions to contaminated plating defect e main area to focus on would be improve- ment of the PCB fabrication process. Foreign Object Debris (FOD) (Case Study 3) e de-wetting issue on the soldered SOT com- ponent lead is shown in Figures 15, 16 and 17. Analysis of Foreign Object Debris (FOD) results e foreign object debris inhibited the SOT lead from contacting the solder and caused de- wetting. e SOT lead component substrate was copper with a tin plating surface treat- ment. According to the FT-IR spectrum ana- lyzed, the foreign object debris had a similar spectrum to cellulose (Figures 17, 18). Figure 13: SEM image and EDX analysis on PCB pad surface showing good wetting. Figure 14: Microscope and X-ray image on solder joint on contaminated pad. Figure 15: Areas focused on for de-wetting issue. Figure 16: FOD observed between SOT lead and solder fillet in red highlighted area from Figure 15. Figure 17: Microscopy image of de-wetting at the SOT solder joint and visual image of foreign object debris.