Reliability of soldered joints for aerospace applications

Known to be highly reliable, Tin-Lead (SnPb) solders have long been used in commercial and aerospace electronic assemblies due to their ability to withstand thermo-mechanical fatigue. A number of constitutive and thermo-mechanical life models for SnPb soldered joints can be used to determine whether a given board design meets the reliability requirements of a system. Known to be highly reliable, Tin-Lead (SnPb) solders have long been used in commercial and aerospace electronic assemblies due to their ability to withstand thermo-mechanical fatigue. A number of constitutive and thermo-mechanical life models for SnPb soldered joints can be used to determine whether a given board design meets the reliability requirements of a system.Due to environmental and toxicological concerns, government legislations worldwide now limit the use of Pb in manufacturing processes. Therefore, the aerospace industry must understand the reliability of proposed Pb-free alternatives prior to using them in the aerospace applications. In order to improve the space-readiness of Pb-free solders, a well-rounded collection of space-specific test results must be compiled and test-verified predictive life models must be developed. Finally, quality control processes associated with manufacturing, handling, and repairing Pb-free solders will have to be created before the space industry can make the transition from SnPb to Pb-free solders.