Reliability of soldered joints for aerospace applications

Brigitte Desrochers, Ryerson University

Date of Award

2007

Degree Type

Thesis Project

Degree Name

Master of Engineering (MEng)

Department

Mechanical Engineering

First Advisor

Zouheir Fawaz

Abstract

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.