This chapter provides an introduction to induction soldering. It also illustrates the classification of the different soldering processes according to the heat source, as described in the German standard, Soldering: Categorization of Processes According to Energy Sources, Process Descriptions.

This chapter presents a brief review of the history of brazing and soldering. It illustrates complicated soldering techniques and masterful goldsmith work, as demonstrated by the famous gold mask of the Egyptian Pharaoh Tutankhamun. The chapter includes the image of a painting from Egypt circa 1475 B.C. that shows a goldsmith soldering with a blowpipe. Numerous similar images have been found in the tombs of ancient Egypt that offer insight into the practices of gold workers from the period, including the use of processes such as smelting, forging, and joining with both brazing and soldering.

This chapter explains the fundamentals of soldering technology and provides an overview of the soldering process. It discusses the wetting of the molten solder filler metal to the base material surface and the design aspects when induction heating is used to make the solder joint.

This chapter presents the following groupings of metals and alloys that are soldered together: steel and iron-base alloys, aluminum and aluminum alloys, and copper and copper alloys. It also presents the ancillary materials and process methods that assist the solder filler metal in completing the solder joint through induction heating. The chapter focuses on the selection of fluxes and the use of inert gases or even vacuum to realize an oxide-free base material surface both before and during the soldering process.

This chapter details various induction soldering processes, including soldering with manually fed solder, soldering with filler metal (preplaced) preforms, soldering with solder coating, and soldering with an automated solder wire feeder.

This chapter focuses on factors that influence the mechanical properties of a soldered joint, including solder material, base material, solder joint design, soldering surface, soldering temperature, and test methodology.

This chapter describes important aspects of the interrelationship between the workpiece and the inductor coil, an understanding of which is essential for achieving an efficient soldering process and a solder joint with the desired performance and reliability. It also discusses induction soldering machine operation parameters, including temperature measurement and control sensors. The chapter illustrates the equipment used in a fully automated induction heating system. Fully automated soldering systems include temperature monitoring devices to control the temperature-time profile, the movement of workpieces, the supply of solder filler metal and flux, and the provision of shielding gas in the solder joint area.

This chapter explores case studies on using induction heating for joining applications, encompassing both soldering and brazing to demonstrate versatility. Each study focuses on inductor coil design, workpiece geometry, and production quantities, emphasizing optimization due to the interplay between material geometry, coil configuration, and process parameters like generator frequency and power. The case studies provide real-world data on effectively implementing induction heating in joining processes.

This chapter discusses the critical soldering faults that lead to quality degradation and potential failure of a soldered connection. It then describes the types of nondestructive evaluations used to inspect soldered and brazed joints, including dimensional and visual inspection, ultrasonic testing, radiographic examination, dye penetrant inspection, and leak testing, including overpressure tests. The chapter also provides an overview of destructive physical analysis.

This chapter describes the general hazards of induction heating and the hazards that are specific to induction joining processes. It also includes a brief discussion of economic considerations in the use of induction soldering.

This appendix presents the United States, German and European soldering and brazing standard specifications.

The detailed heating requirements for specific applications must be considered before construction and implementation of any induction heating process. These requirements may include considerations such as type of heating, throughput and heating time, workpiece material, peak temperature, and so forth. The major applications of induction technology include through heating, surface heating (for surface heat treatment), metal melting, welding, brazing, and soldering. This chapter summarizes the selection of equipment and related design considerations for these applications.

Because of its speed and ease of control, induction heating can be readily automated and integrated with other processing steps such as forming, quenching, and joining. Completely automated heating/handling/control systems have been developed and are offered by induction equipment manufacturers. This chapter deals with materials handling and automation. First, it summarizes basic considerations such as generic system designs, fixture materials, and special electrical problems to be avoided. Next, it describes and provides examples of materials-handling systems in induction billet heating, bar heating, heat treatment, soldering, brazing, and other induction-based processes. The final section discusses the use of robots for parts handling in induction heating systems.