Research On The Reliability Of Lead-free Soldering Process For Avionics

Current relevant regulations,such as the European Union’s Waste Electrical and Electronic Equipment Directive(WEEE)and the Directive on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment(ROHS),and China’s“Administrative Measures on Pollution Control of Electronic Information Products” have been In effect,the international electronics manufacturers are actively working on the transition of their products to lead-free production.At present,a lot of work has been done in the development and research of lead-free solder at home and abroad,but for the sake of high reliability,the current avionics is still in the lead soldering process.However,as component suppliers in developed countries withdraw from the military product market or embargo or obsolete obsolescence,leading to the inability to purchase leaded devices with exemptions,the development trend of lead-free devices for military and aerospace electronic products has become irresistible.This article first explored the process range of the lead-free reflow curve in the QFN device soldering test,and compared and optimized the best solder paste(ALPHA CVP-390).Second,the BGA and QFP soldering tests were performed with the optimized solder paste.Optimized printing test,optimized test of reflow curve;finally,X-ray inspection and metallographic analysis of solder joints.The mechanical simulation analysis of BGA lead-free solder joints was performed by using ANSYS software.The model was subjected to temperature cycling load,the distribution of stress and strain was observed,the positions of dangerous solder joints were determined,and the thermal fatigue life of solder joints was predicted.The research results in this paper have broad guiding significance for the selection and evaluation of lead-free solder paste and the lead-free production of surface mount technology.It has important engineering practical value for lead-free production of electronic products.