Study of electrical resistance for solder joint quality

• Main Author: Chan, Joyce Hui Yi.
• Other Authors: Lye Sun Woh
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Materials::Material testing and characterization
• Online Access: http://hdl.handle.net/10356/45650
• Institution: Nanyang Technological University

Many products are manufactured and assembled from a combination of different components. To connect these components, good combined joints are paramount. Soldering is a method of combining joints and it is the main focused fastening method used in this project as it is permanent, easily combined, less time consuming for repetitive testing, and less costly. Good quality joints undergo verification of overall joint performance in terms of being defect-free, within acceptable levels of residual stresses and distortion, and possession of acceptable heat-affected zone (HAZ) properties. Quality assessment testing is essential to avoid joint failures and to ensure the work reliability. Joining procedures and skills of the maker are also mainly assessed through the manufacturing and testing of the specimen joints. Therefore, it is important to ensure the overall performance and quality of the joint. To test on quality of joints, destructive and non-destructive testing methods are commonly applied. These methods may be conducted in either lab-based or in-situ based depending on the degree of control. The current available methods of joint quality testings are time-consuming, destructive and/or less precised. Thus, the development of a quicker and non-destructive alternative for quality testing is essential to improve on both the testing speed and the ability of identifying any defects along the joints and the overall product. This project report contains an indepth study on this technique of joint quality testing with the presence of defects. The technique introduced covers the quality testing through the examining of the electrical resistance flow between metal pieces which are soldered together with joint(s). Experiments are carried out to observe and study how the electrical resistance changes under different conditions. In addition, new resistance equation is formulated and been verified with additional testing on other materials as well as other joining method (welding.