Board Level Lead-Free Solder Joints Reliability Analysis Under Drop Shock Loading

Comparing to electronic components which have lead, those components which are lead-free be of different mechanics and reliability characteristics. Meanwhile, with the popularity of some handheld or portable electronic products, it is inevitable to drop when we use them. Those drop or impact may not only lead mechanical failure of electronic product's shell, but also cause failure of the BGA which connects to PCB inside the shell due to large drop stress and strain. Because the failure of electronic components is mainly caused by solder joints failure. So it is necessary to study BGA solder joints'reliability under mechanical shock in order to offer some help of reliability experiment and failure mode expectation. Based on JEDEC standard board reliability, this paper studied reliability of solder joints of a circular PCB.Main work and conclusions:1. Reviewed history and development of board level lead-free solder joints'reliability analysis, introduced analysis about board level lead-free solder joints'reliability in and abroad. Analyzed characteristic of lead-free, handheld or portable electronic products, put forward the keypoints and difficulties.2. Aimed to the unscientific statistic limitation of JEDEC standard to do failure mode expectation, we designed a circular PCB.3. Utilizing hammer method and finite element software ABAQUS to do modal experiment and modal numerical simulation of PCB with chips and electronic components in free boundary status and fixed boundary status, and got the modal frequencies and modal shape. Due to the PCB's elastic module is...