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How clean is clean? When manufacturing electronic assemblies, impurities left on the board’s surface or underneath the components may lead to in-field failures. To shed light on this issue, IPC will be holding a technical webinar on 23 January 2018 to provide an overview of methodologies available to properly assess the cleanliness of your post clean assemblies.
Topics for discussion include surface analysis for cleanliness assessment; measurement of standards demands; use of analysis processes in the production line; and handling of analysis tools for quality control of supplied components.
The webinar will be led by Dr. Helmut Schweigart, head of the technology department at Zestron.
For more information or to register, click here.
Reza Ghaffarian, Jet Propulsion Laboratory, California Institute of Technology
Electroless nickel/electroless palladium/immersion gold (ENEPIG) surface finish for PCBs has now become a key surface finish that is used for both tin-lead and lead-free solder assemblies. This article presents the reliability of LGA component packages with 1156 pads assembled with tin-lead solder onto PCBs with an ENEPIG finish and then subjected to thermal cycling and then isothermal aging.
Gerjan Diepstraten, Vitronics Soltec B.V.
Selective soldering is a process with more than 100 different parameters that may impact soldering performance. A robust selective soldering process should have a wide process window that is able to handle variations in material quality. In this paper, critical process parameters are discussed as well as methods that can be used to widen the process window.
Ben Gumpert, William Fox, and C. Don Dupriest, Lockheed Martin
When soldering to ENEPIG, all of the palladium is dissolved into the solder joint, and creates a palladium-rich region at the base of the solder joint. The shrinking solder joint sizes due to the ever decreasing size of parts cause the relative size of this palladium-rich microstructure to grow relative to the overall joint thickness. This study evaluates the impact of industry standard Pd thicknesses on thin solder joints through shear testing.