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.

Magnetic field imaging (MFI), generally understood as mapping the magnetic field of a region or object of interest using magnetic sensors, has been used for fault isolation (FI) in microelectronic circuit failure analysis for almost two decades. Developments in 3D magnetic field analysis have proven the validity of using MFI for 3D FI and 3D current mapping. This article briefly discusses the fundamentals of the technique, paying special attention to critical capabilities like sensitivity and resolution, limitations of the standard technique, sensor requirements and, in particular, the solution to the 3D problem, along with examples of its application to real failures in devices.

Time-domain based characterization methods, mainly time-domain reflectometry (TDR) and time-domain transmissometry (TDT), have been used to locate faults in twisted cables, telegraph lines, and connectors in the electrical and telecommunication industry. This article provides a brief review of conventional TDR and its application limitations to advanced packages in semiconductor industry. The article introduces electro optical terahertz pulse reflectometry (EOTPR) and discusses how its improvements of using high frequency impulse signal addressed application challenges and quickly made it a well-adopted tool in the industry. The third part of this article introduces a new method which combines impulse signal and the TDT concept, and discusses a combo TDR and TDT method. Cases studies and application notes are shared and discussed for each technique. Application benefits and limitations of these techniques (TDR, EOTPR, and combo TDR/TDT) are summarized and compared.

After the fault-tree, a failure-cause identification method has identified potential failure causes and the failure analysis team has prepared a failure mode assessment and assignment (FMA&A). The team knows specifically what to search for when examining components and subassemblies from the failed system. There are numerous techniques and technologies available for examining and analyzing components and subassemblies, which are categorized as follows: optical approaches, dimensional inspection and related approaches, nondestructive test approaches, mechanical and environmental approaches, and chemical and composition analysis for assessing material characteristics. This chapter is a detailed account of the working principle and the steps involved in these techniques and technologies.

This article focuses on characterization techniques used for analyzing the physical behavior and chemical composition of thermoset resins, namely chromatography and infrared spectroscopy. The main purpose is to give sufficient detail to permit the reader understand a particular test technique and its value to the thermoset resin field. Epoxy resins are emphasized in the examples because they dominate the airframe and aerospace industries. The article also provides information on two categories of characterization of the processing behavior of thermoset. The first studies the thermal properties of reactive thermoset systems, while the second utilizes these thermal characteristics as the basis for monitoring and control during processing.

This article addresses some established protocols in characterizing thermoplastics, whether they are homogeneous resins, alloyed or blended compositions, or highly modified thermoplastic composites. It begins with a description of various approaches used for the determination of molecular weight (MW) by viscosity measurements. This is followed by a discussion of the use of cone and plate and parallel plate geometries in determining the viscoelastic properties of a polymer melt. Details on some of the chromatographic techniques that allow determination of MW and MW distribution of polymers are then provided. The article concludes with information on three distinctive, but complementary operations of thermoanalytical techniques, namely differential scanning calorimetry, thermogravimetric analysis, and thermomechanical testing.

This article discusses electrical testing and recommended procedures for determining the electrical properties of insulating materials, with particular emphasis on plastics. It describes the electrical characteristics of various forms of plastics and also presents definitions of the terms used in connection with testing and specifying plastics for electrical applications.

This article is a brief account of various factors pertinent to the characterization of materials and analysis of optical components, namely transmission, haze, yellowness, refractive index, surface irregularity, birefringence, internal contamination, surface gloss, and color. In addition, details on ad hoc tests used for determining the acceptability of a plastic part for its application are provided, along with typical examples.

Many scientific-technological advances depend critically on solid-state elastic properties, their magnitudes, and their responses to variables like stress and temperature. This chapter provides the definitions and descriptions of elastic constants and emphasizes five aspects of engineering-material solid-state elastic constants: general properties; interrelationships; relationships, especially thermodynamic to other physical properties; changes during cooling from ambient to near-zero temperature; and near-zero-temperature behavior.

Specific heat is a fundamental property that relates the total heat per unit mass added to a system to the resultant temperature change of the system. This chapter begins with the definition and historical development of specific heat. Thermodynamic and solid state relationships are presented which include discussions about lattice specific heat and the effects of magnetic and superconducting transitions. Data sources for practical applications and methods of estimating specific heat for materials are also included. The chapter concludes with a section concerning the measurement of specific heat at low temperatures.

Specific heat and thermal expansion are closely related. Following a discussion on thermal expansion theory, methods of measurement techniques are presented along with their advantages and disadvantages. The results of the measurements are then summarized for three classes of materials: metallics, nonmetallics, and composites. Because predicting thermal expansion values for unmeasured or novel materials is useful, the chapter also describes the means of making educated guesses for low-temperature values. A short discussion on how thermal expansion data can be used is followed by a section describing where such data can be found.

This chapter presents basic principles and the theoretical results of heat transport in solids. Thermal conductivity and thermal diffusivity are the principal properties discussed. Discussions are also included on the effects of temperature, magnetic field, and metallurgical variations caused by composition, processing, and heat-treatment differences. Numerous graphs illustrate the qualitative and quantitative effects of these variables. Measurement methods and associated accuracies and pertinent empirical correlations are presented.

This chapter presents topics pertaining to resistance at cryogenic temperatures: measurement, the resistive mechanisms, and available data. The chapter also presents brief descriptions of the various mechanisms that are operative in producing resistance at low temperatures. The alloys discussed are the nondilute mixtures of metals. An introduction to low-temperature electrical properties of specific metals and alloys is included.

This chapter provides a view of magnetism in materials used at low temperatures. The discussion covers the concepts, definitions, and systems of units that are unique to the study of magnetic properties. The chapter provides a description of some of the techniques and devices used for determining magnetic properties.

The mechanical properties of a material describe the relations between the stresses acting on the material and its resulting deformations. Stresses capable of producing permanent deformations, which remain after the stresses are removed, are considered in this chapter. The effects of cryogenic temperatures on the mechanical properties of metals and alloys are reviewed in this chapter; the effects on polymers and glasses are discussed briefly. The fundamental mechanisms controlling temperature-dependent mechanical behavior, phenomena encountered in low-temperature testing, and the mechanical properties of some representative engineering metals and alloys are described. Modifications of test procedures for low temperatures and sources of data are also included.

This chapter reviews the concepts of fracture mechanics and their application to materials evaluation and the design of cryogenic structures. Emphasis is placed on an explanation of technology, a review of fracture mechanics testing methods, and a discussion on the many factors contributing to the fracture behavior of materials at cryogenic temperatures. Three approaches of elastic-plastic fracture mechanics are covered, namely the crack opening displacement, the J-integral, and the R-curve methods. The chapter also discusses the influence of thermal and metallurgical effects on toughness at low temperatures.

This chapter concentrates on very low-temperature martensitic transformations, which are of great concern for cryogenic applications and research. The principal transformation characteristics are reviewed and then elaborated. The material classes or alloy systems that exhibit martensitic transformations at very low temperatures are discussed. In particular, the martensitic transformations and their effects in austenitic stainless steels, iron-nickel alloys, practical superconductors, alkali metals, solidified gases, and polymers are discussed.

This chapter discusses the compatibility problems that arise from chemical or physical interactions between liquefied gases and the common materials used in their production, storage, transportation, distribution, and use. The discussion covers the compatibility of materials with liquid oxygen and liquid fluorine. Hydrogen-environment embrittlement is unique to low-temperature hydrogen systems and is also discussed.

This chapter discusses the structural alloys being used for cryogenic applications in commercially significant quantities. It emphasizes the practical considerations involved in the material selection process and provides the information necessary to make preliminary selections of alloys most suitable for the intended cryogenic application. The chapter provides general information on a class or group of alloys, their representative mechanical and physical properties, and their fabrication characteristics. The materials covered are austenitic stainless steels, nickel steels, aluminum alloys, and other metals and alloys.

Composite systems for cryogenic applications are discussed in this chapter. This chapter emphasizes filamentary-reinforced composites because they are the most widely used composite materials. It begins with a discussion on the approach to designing and fabricating with low-pressure laminate composites. This is followed by a section providing an overview of the materials in modern cryogenic technology. Then, the chapter describes the effect of cryogenic temperatures on materials properties; it also introduces the various joining techniques developed for composite materials. The effects of radiation on the properties of the materials are covered as well as the processes involved in testing laminates at cryogenic temperatures. Finally, the chapter provides information available on concrete aggregate composites.