Industry News | 2012-02-07 16:20:22.0
Nihon Superior announces that its Senior Technical Advisor Keith Sweatman will present the paper titled “Effect of Cooling Rate on the Intermetallic Layer in Solder Joints” at the upcoming IPC APEX Expo.
Industry News | 2010-07-29 15:10:06.0
Universal Instruments’ Advanced Process Lab hosted the first Advanced Research in Electronics Assembly (AREA) Consortium meeting of 2010 at the Treadway Inn in Owego, NY on June 16-17. Nearly 80 attendees from the 29 member companies participated in the two-day event, which will also be presented in subsequent webcasts. Topics ranged from thermal interface assembly to a continuing analysis of lead-free solder microstructure and reliability.
Technical Library | 2019-04-17 21:29:14.0
Electroless nickel electroless palladium immersion gold (ENEPIG) surface finish for printed circuit board (PCB) has now become a key surface finish that is used for both tin-lead and lead-free solder assemblies. This paper presents the reliability of land grid array (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.
Technical Library | 2015-02-12 16:57:56.0
Electronic systems are known to be affected by the environmental and mechanical conditions, such as humidity, temperature, thermal shocks and vibration. These adverse environmental operating conditions, with time, could degrade the mechanical efficiency of the system and might lead to catastrophic failures.The aim of this study is to investigate the mechanical integrity of lead-free ball grid array (BGA) solder joints subjected to isothermal ageing at 150°C for up to 1000 hours. Upon ageing at 150°C the Sn-3.5Ag solder alloy initially age-softened for up to 200 hours. This behaviour was linked to the coarsening of grains. When aged beyond 200 hours the shear strength was found to increase up to 400 hours. This age-hardening was correlated with precipitation of hard Ag3Sn particles in Sn matrix. Further ageing resulted in gradual decrease in shear strength. This can be explained as the combined effect of precipitation coarsening and growth of intermetallic layer. The fractured surfaces of the broken solder balls were also investigated under a Scanning Electron Microscope. The shear failures were generally due to ductile fractures in bulk solders irrespective of the ageing time.
SMTnet Express August 29, 2013, Subscribers: 26233, Members: Companies: 13474, Users: 35110 Effect of Gold Content on the Microstructural Evolution of SAC305 Solder Joints Under Isothermal Aging by Mike Powers, Jianbiao Pan, Julie Silk, Patrick
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