Anti-vibration Design of Surface Mount Devices in the Aerospace Electronic Equipment

Surface Mount Devices (SMD) greatly improve the product integration and the chip package area ratio. On the other hand, due to the large number of pins and the very small volume of solder joints, it is easy to crack solder joints in the vibration environment of spacecraft launching, which causes the strength reliability problem. The bending stiffness of SMDs is compared with that of printed circuit boards (PCB) and is analyzed by using the bending stiffness theory of plate in this paper. The key factors, which affect the vibration reliability of SMD solder joints, are obtained. A PCB stiffening rib design method to improve the vibration reliability of SMD is given from the aspect of the structural system design of the electronic equipment. By using the finite element method (FEM), it is verified that this method can greatly reduce the relative displacement between SMDs and PCBs, and effectively improve the anti-vibration characteristics of SMD solder joints. The method also has the advantages of reducing the overall size of electronic equipment and facilitating the application of heat sink to the heating components, and has been widely used in various types of aerospace electronic equipment.