Issue link: https://iconnect007.uberflip.com/i/1528798
58 SMT007 MAGAZINE I NOVEMBER 2024 with small traces and vias vulnerable to the effects of ionic contamination. e lead-free solder used in the assemblies was highly sus- ceptible to forming conductive paths when exposed to moisture. Reports indicated that ECM caused dendrite formation between the power and ground planes, leading to short cir- cuits and intermittent failures in some units. e problem was exacerbated by the con- sole's thermal design, which allowed signifi- cant heat buildup during use. As the console cooled down, condensation could form, fur- ther promoting the conditions necessary for ECM to occur. ese cases demonstrate the vulnerability of electronic systems operating in harsh environ- ments and the critical need for proactive mea- sures to mitigate the risks associated with resi- due and electrochemical migration. The Impact of Miniaturization on Residue Tolerance e trend toward miniaturization in electronics has significantly compounded the challenges associated with resi- dues on circuit assemblies. As electronic devices shrink, the spacing between con- ductive elements, such as traces and pads, becomes smaller, oen approach- ing micrometer scales. is reduction in spacing lowers the voltage thresh- old required for electrochemical migra- tion to occur. Smaller distances between conductive elements provide less physical room for insulating barriers, meaning that even tiny amounts of residue can bridge these gaps and form conductive pathways, leading to increased susceptibility to electrochemical migration. As a result, the tolerance for any form of contamination, particularly ionic res- idues, has decreased dramatically. Even resi- dues that might have been inconsequential in larger, more widely spaced circuits can pose severe risks in miniaturized assemblies, where the smaller dimensions amplify the potential for failure. Furthermore, miniaturization has intro- duced new challenges in cleaning and residue removal. Low-standoff components—those with very little clearance between the compo- nent body and the PCB—are now commonly used in compact designs, making it more chal- lenging for cleaning agents to penetrate under these components and remove contaminants effectively. Traditional cleaning methods, such as non-diffused or coherent nozzles, are oen ineffective in reaching the narrow spaces under low-standoff components, leading to the risk of residual contamination being le behind. Advanced cleaning techniques, includ- ing diffused spray patterns and chemical addi- tives that reduce surface tension, have become essential to ensure thorough cleaning in minia- turized assemblies. However, even with these advancements, the reduced tolerances in min- iaturized designs mean that the margin for