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.

Joining comprises a large number of processes used to assemble individual parts into a larger, more complex component or assembly. The selection of an appropriate design to join parts is based on several considerations related to both the product and the joining process. Many product design departments now improve the ease with which products are assembled by using design for assembly (DFA) techniques, which seek to ensure ease of assembly by developing designs that are easy to assemble. This chapter discusses the general guidelines for DFA and concurrent engineering rules before examining the various joining processes, namely fusion welding, solid-state welding, brazing, soldering, mechanical fastening, and adhesive bonding. In addition, it provides information on several design considerations related to the joining process and selection of the appropriate process for joining.

Solid-state welding processes are those that produce coalescence of the faying surfaces at temperatures below the melting point of the base metals being joined without the addition of brazing or solder filler metal. This chapter discusses solid-state welding processes such as diffusion welding, forge welding, roll welding, coextrusion welding, cold welding, friction welding, friction stir welding, explosion welding, and ultrasonic welding.

Arc welding applies to a large and diversified group of welding processes that use an electric arc as the source of heat to melt and join metals. This chapter provides a detailed overview of specific arc welding methods: shielded metal arc welding, flux cored arc welding, submerged arc welding, gas metal arc welding, gas tungsten arc welding, plasma arc welding, plasma-GMAW welding, electroslag welding, and electrogas welding. The basic characteristics of gases used for shielding during arc welding are briefly discussed.

Resistance welding is a group of processes in which the heat for welding is generated by the resistance to the flow of an electrical current through the parts being joined. This chapter discusses the processes, advantages, and limitations of specific resistance welding processes, namely resistance spot welding, resistance seam welding, projection welding, flash welding, and upset welding.

This chapter discusses the fusion welding processes, namely oxyfuel gas welding, oxyacetylene braze welding, stud welding (stud arc welding and capacitor discharge stud welding), high-frequency welding, electron beam welding, laser beam welding, hybrid laser arc welding, and thermit welding.

During fusion welding, the thermal cycles produced by the moving heat source causes physical state changes, metallurgical phase transformations, and transient thermal stresses and metal movement. This chapter begins by discussing weld metal solidification behavior and the solid-state transformations of the main classes of metals and alloys during fusion welding. The main classes include work- or strain-hardened metals and alloys, precipitation-hardened alloys, transformation-hardened steels and cast irons, stainless steels, and solid-solution and dispersion-hardened alloys. The following section provides information on the residual stresses and distortion that remain after welding. The focus then shifts to distortion control of weldments. Inclusions and cracking are discussed in detail. The chapter also discusses the causes for reduced fatigue strength of a component by a weld: stress concentration due to weld shape and joint geometry; stress concentration due to weld imperfections; and residual welding stresses. Inspection and characterization of welds are described in the final section of this chapter.

This chapter presents a comprehensive coverage of mechanical fastening methods. It begins with a discussion on the advantages and disadvantages of mechanical fastening followed by sections providing information on mechanically fastened joints and the selection of the correct fastener system. The chapter then describes important structural fasteners, namely bolts, screws, pins, collar fasteners, rivets, blind fasteners, machine pins, and spring clip fasteners. The following sections describe the process involved in presses, shrink fits, hole generation, and fastener installation. The chapter ends with information on miscellaneous mechanical fastening methods.

Adhesive bonding is a widely used industrial joining process in which a polymeric material is used to join two separate pieces (the adherends or substrates). This chapter begins with a discussion on the advantages and disadvantages of adhesive bonding, followed by a section providing information on the theory of adhesion. The chapter then describes the considerations for designing adhesively bonded joints and for testing or characterizing adhesive materials. The following section covers the characteristics of the most important synthetic adhesive systems and five groups of adhesives, namely structural, hot melt, pressure sensitive, water based, and ultraviolet and electron beam cured. The chapter ends with a discussion on some general guidelines for adhesive bonding and the basic steps in the adhesive bonding process.

This chapter reviews materials issues encountered in joining, including challenges involved in welding of dissimilar metal combinations; joining of plastics by mechanical fastening, solvent and adhesive bonding, and welding; joining of thermoset and thermoplastic composite materials by mechanical fastening, adhesive bonding, and, for thermoplastic composites, welding; the making of glass-to-metal seals; and joining of oxide and nonoxide ceramics to themselves and to metals by solid-state processes and by brazing. The classification, types, applications, and the mechanism of each of these methods are covered. The factors influencing joint integrity and the main considerations in welding dissimilar metal combinations are also discussed.

This article examines the role of alloying in the production and use of lead and tin. It describes the various categories and grades of lead and lead-base alloys along with their nominal compositions and corresponding UNS numbers. It also discusses the composition and properties of lead used in battery grids, type metals, and bearings. It, likewise, discusses the use of tin in various types of solder and in bearings and provides composition and property data for application-specific designations and grades. The article also discusses the effect of impurities in tin-lead solders and the amounts and combinations in which they are found.

This article discusses the composition, structures, properties, and behaviors of aluminum alloys and explains how they correspond to specific alloying elements. It begins with an overview of the general characteristics of wrought and cast aluminum alloys, the four-digit classification system by which they are defined, and the applications for which they are suited. It then explains how primary alloying elements, second-phase constituents, and impurities affect yield strength, phase formation, and grain size and how they induce structural changes that help refine certain alloys. The article also explains how primary alloying elements affect corrosion and wear behaviors and how they influence fabrication processes such as forming, forging, welding, brazing, and soldering.

Most of the counterfeit parts detected in the electronics industry are either novel or surplus parts or salvaged scrap parts. This article begins by discussing the type of parts used to create counterfeits. It discusses the three most commonly used methods used by counterfeiters to create counterfeits. These include relabeling, refurbishing, and repackaging. The article presents a systematic inspection methodology that can be applied for detecting signs of possible part modifications. The methodology consists of external visual inspection, marking permanency tests, and X-ray inspection followed by material evaluation and characterization. These processes are typically followed by evaluation of the packages to identify defects, degradations, and failure mechanisms that are caused by the processes (e.g., cleaning, solder dipping of leads, reballing) used in creating counterfeit parts.

X-ray imaging systems have long played a critical role in failure analysis laboratories. This article begins by listing several favorable traits that make X-rays uniquely well suited for non-destructive evaluation and testing. It then provides information on X-ray equipment and X-ray microscopy and its application in failure analysis of integrated circuit (IC) packaging and IC boards. The final section is devoted to the discussion on nanoscale 3D X-ray microscopy and its applications.

The complexity of semiconductor chips and their packages has continuously challenged the known methods to analyze them. With larger laminates and the inclusion of multiple stacked die, methods to analyze modern semiconductor products are being pushed toward their limits to support these 2.5D and 3D packages. This article focuses on these methods of fault isolation, non-destructive imaging, and destructive techniques through an iterative process for failure analysis of complex packages.

As semiconductor feature sizes have shrunk, the technology needed to encapsulate modern integrated circuits has expanded. Due to the various industry changes, package failure analyses are becoming much more challenging; a systematic approach is therefore critical. This article proposes a package failure analysis flow for analyzing open and short failures. The flow begins with a review of data on how the device failed and how it was processed. Next, non-destructive techniques are performed to document the condition of the as-received units. The techniques discussed are external optical inspection, X-ray inspection, scanning acoustic microscopy, infrared (IR) microscopy, and electrical verification. The article discusses various fault isolation techniques to tackle the wide array of failure signatures, namely IR lock-in thermography, magnetic current imaging, time domain reflectometry, and electro-optical terahertz pulse reflectometry. The final step is the step-by-step inspection and deprocessing stage that begins once the defect has been imaged.

There are several analytical methods available that can be used in-line on whole wafers as well as off-line on de-processed products that are returned from the field. These techniques are surface analytical techniques that can be used to characterize the bulk of the material. The main six methods used in semiconductor industry are: Auger spectroscopy, dynamic secondary ion mass spectroscopy, time of flight static secondary ion mass spectroscopy (ToF-SIMS), X-ray photoelectron spectroscopy, scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX), and transmission electron microscope-EDX. This review specifically addresses ToF-SIMS and describes some typical examples of the application of Auger and SEM-EDX.

Steels contain a wide range of elements, including alloys as well as residual processing impurities. This chapter describes the chemical composition of low-alloy AISI steels, which are classified based on the amounts of chromium, molybdenum, and nickel they contain. It explains why manganese is sometimes added to steel and how unintended consequences, such as the development of sulfide stringers, can offset the benefits. It also examines the effect of alloying elements on the iron-carbon phase diagram, particularly their effect on transformation temperatures.

This chapter begins by presenting a generic eutectic phase diagram and identifying critical points, lines, and features. It then describes the composition and properties of aluminum-silicon and lead-tin eutectic systems, the characteristics of eutectic morphologies, the solidification and scale of eutectic structures, and the competitive growth of dendrites and eutectic colonies or cells. It also examines the different types of precipitation structures that form during slow cooling cycles.