Research On Reliability Of High Density SMT Aerospace Products

High.density assembly of aerospace electronics equipment is an importantdirection of research linking technology. Based on the experiment, first have anresearch f on parameters of high density aerospace products’ each process, includingprinting parameters, placement parameters, and made a detailed presentation of thereflow process and the temperature curve, and complete high density aerospaceproducts under different welding process parameters, including different packaging,different sizes of BGA devices. Secondly, execute the PCB board to acceleratedenvironmental testing (including temperature cycle test and vibration test) underdifferent welding process parameters, and finally through the relevant testingequipment, such as using X-Ray detector to detect the unvisible point under differentwelding process parameters, using optical microscopy, scanning electron microscopy,to analysis the ingredient and degree of solder joints before and after environmentaltesting.In the experimental results, finding that it contribute to the formation of Cu.Snalloy which temperature profile is higher than the temperature over220℃for atleast two seconds, The form of Cu.Sn alloy contributes to improve the reliability ofsolder joints. The above summary of the final analysis of the high density differenceaerospace reliability under different process parameters for the optimization of theprocess parameters with high joint reliability.