Laser soldering of surface-mounted devices for high-reliability applications

Laser soldering processes are characterized by the temperature during soldering within the joint as a function of time and as a function of the soldering parameters. These parameters are optimized by a metallurgical assessment of the quality of the joints. The thermal-fatigue properties of soldered joints important for space applications were investigated for different solder alloys by the thermal-cycling test according to ESA PSS-01-704. In addition, measurements of the shear strength were carried out for a small number of specimens in order to check if the mechanical strength of joints is altered by thermal cycling.