This chapter presents an overview and survey of solder alloy systems. Extensive reference is made to phase diagrams and their interpretation. The chapter describes the effect of metallic impurities on different solders. The chapter concludes with a review of the key characteristics of eutectic alloys and of the factors most effective at depressing the melting point of solders by eutectic alloying.

Brazing and soldering processes use a molten filler metal to wet the mating surfaces of a joint, with or without the aid of a fluxing agent, leading to the formation of a metallurgical bond between the filler and the respective components. This chapter discusses the characteristics, advantages, and disadvantages of brazing and soldering. The first part focuses on the fundamentals of the brazing process and provides information on filler metals and specific brazing methods. The soldering portion of the chapters provides information on solder alloys used, selection criteria for base metal, the processes involved in precleaning and surface preparation, types of fluxes used, solder joint design, and solder heating methods.

This chapter presents several materials and processes related to soldering technology. It first provides information on lead-free solders, followed by sections devoted to flip-chip processes, diffusion soldering, and modeling. Scanning acoustic microscopy and fine-focus x-ray techniques are also discussed. The chapter describes several evaluation procedures and tests developed to measure solderability and standards for process calibration. The chapter also describes the characteristics of reinforced solders, amalgams used as solders, and other strategies to boost the strength of solders. Further, the chapter considers methods for quantifying the mechanical integrity of joints and predicting their dimensional stability under specified environmental conditions. It discusses the effects of rare earth elements on the properties of solders. The chapter concludes with information on advanced joint characterization techniques.

This chapter describes the factors that affect the corrosion performance of aluminum assemblies joined by methods such as welding, brazing, soldering, and adhesive bonding. The factors covered include galvanic effects, crevices, and assembly stresses in products susceptible to stress-corrosion cracking.