Reliability of Soldered Joints: A Description of the State of the Art

Abstract

Damage to components during soldering and degradation of soldered joints is determined to a large extent by the mechanical properties and the metallurgy of solder alloys and soldered joints. Knowledge of these properties is required for understanding of the mechanisms of damage and degradation. A compilation of this background knowledge is presented in this first article. It comprises the elastic, strength, creep and fatigue characteristics of tin/lead solders. Further, the metallurgy of tin/lead solders and soldered joints is discussed in terms of solidification structures, formation of intermetallic compounds, ageing of structures and effects of different solderable metallisations and soldering technology.