Nanopackaging

Level one electronics packaging is traditionally defined as the design and production of the encapsulating structure that provides mechanical support, environmental protection, electrical signal and power I/O, and a means of heat dissipation for the Si chip, whether digital or analog, processor, or memory. Level two packaging is then the integration of these packaged chips into a board-level system that similarly provides mechanical support, power and signal delivery and interconnections, and thermal dissipation. Of course, nowadays the chip is often mounted directly on the board (chip-on-board, direct chip attach, flip chip), and the packaging process actually begins with the chip fabrication (wafer-level packaging), e.g., with solder bumping. The underlying principles of the field are covered in textbooks [1–3], and a multitude of others, e.g. [4], are more research focused. The field is inherently multidisciplinary with electrical, mechanical, and thermal design at its core, with all of these subject to reliability studies and material selection. Figure 1.1 shows the history of the electronics package from the vacuum tube to a multi-chip “system in a package” (SiP). The package has always been the limiting factor to system performance, i.e., the Si chip can operate at higher frequencies than the package.

Modelling technologies are playing a key role in supporting new developments in nano-packaging for electronic systems. This chapter provides an overview of these technologies from continuum modelling using techniques such as finite elements, atomistic models based on molecular dynamics and optimisation under uncertainty, as well as homogenisation methods that link results across the length and timescales. Challenges for these techniques in terms of modelling nano-packaging applications are also discussed.The chapter then goes onto providing a review of these technologies for key design stages in and electronic system such as fabrication, assembly and its performance/reliability. Examples include focused ion beam milling, nanoimprint lithography, electroforming, 3D printing and additive manufacturing, solder paste printing, microwave curing of polymers, impact of underfills on solder joint reliability, thermos-mechanical behaviour of conductive adhesives and performance thermal interface materials. These examples provide the reader with an overview of how these modelling technologies can be applied to real-world nano-packaging applications.

Adhesion and delamination have been pervasive problems hampering the performance and reliability of micro- and nano-electronic devices. In order to understand, predict, and ultimately prevent interface failure in electronic devices, development of accurate, robust, and efficient delamination testing and prediction methods is crucial. Adhesion is essentially a multi-scale phenomenon: at the smallest scale possible, it is defined by the thermodynamic work of adhesion. At larger scales, additional dissipative mechanisms may be active which results in enhanced adhesion at the macroscopic scale and are the main cause for the mode angle dependency of the interface toughness. Undoubtedly, the macroscopic adhesion properties are a complex function of all dissipation mechanisms across the scales. Thorough understanding of the significance of each of these dissipative mechanisms is of utmost importance in order to establish physically correct, unambiguous values of the adhesion properties, which can only be achieved by proper multi-scale techniques.The topic “Advances in Delamination Modeling” has been split into two separate chapters: this chapter discusses the continuum aspects of delamination, while the next chapter deals with the atomistic aspects of interface separation. The chapter starts with a concise overview of the theory on interface fracture mechanics, followed by five applications: (1) buckling-driven delamination in flexible displays, in which a combined numerical-experimental approach is used to establish macroscopic adhesion properties, as a function of mode angle; (2) a multi-scale method to identify the relevant dissipative mechanisms in fibrillating metal/elastomer interfaces that are encountered in stretchable electronics; (3) analysis and prediction of a particular microscale dissipative mechanism at patterned (roughened) interfaces, as a result of the competition between adhesive and cohesive failures; (4) advanced model parameter identification by integrated digital image correlation which essentially eliminates the need for calculating displacements from images prior to parameter identification; and (5) the modeling of the sintering behavior of Ag particles in a thermal interconnect material.

Adhesion and delamination have been pervasive problems hampering the performance and reliability of micro- and nano-electronic devices. In order to understand, predict, and ultimately prevent interface failure in electronic devices, development of accurate, robust, and efficient delamination testing and prediction methods is crucial. Adhesion is essentially a multi-scale phenomenon: at the smallest scale possible, it is defined by the thermodynamic work of adhesion. At larger scales, additional dissipative mechanisms may be active which results in enhanced adhesion at the macroscopic scale and are the main cause for the mode angle dependency of the interface toughness. Undoubtedly, the macroscopic adhesion properties are a complex function of all dissipation mechanisms across the scales. Thorough understanding of the significance of each of these dissipative mechanisms is of utmost importance in order to establish physically correct, unambiguous, values of the adhesion properties, which can only be achieved by proper multi-scale techniques.The topic “Advances in Delamination Modeling” has been split into two separate chapters: this chapter discusses the atomistic aspects of delamination, while the preceding chapter deals with the atomistic aspects of interface separation. The chapter starts with a concise overview of molecular simulation strategies. Next, examples are provided which represent actual materials being developed for electronic packaging: (1) the prediction of thermomechanical properties of an epoxy molding compound (EMC) and the adhesion properties of an EMC/copper interface by means of MD and CG MD approaches; (2) the modeling of wetting, adhesion, and reliability cycling of die attach and via fills; (3) model scaling to discrete element modeling (DEM) for understanding underfill flow; (4) CG modeling of an epoxy molding compound which relates to the first example; (5) molecular modeling of silicate layers used in planarization and encapsulant layers for flat panel displays; (6) mesoscale modeling of diffusion of organic bases which is of concern to photoresist poisoning; and (7) the prediction of thermomechanical properties of a low-k dielectric material, SiOC:H.

Due to the shrinkage in size of many handheld electronic devices such as smartphones and laptop computers, packaging of a large number of components within a limited size chip becomes a challenging issue. Nanoimprint lithography (NIL) provides a low-cost solution in order to cope with the challenge. However, the de-molding process is very critical for determining the printing quality. The interaction between the mold and the substrate greatly affects the patterning result. Therefore it is necessary to understand the interaction between the nano-patterned mold and the substrate. This chapter introduces a multi-scale model by combining molecular dynamic (MD) simulation and a finite element analysis, which could predict the adhesion force between the nano-patterned mold and the polymer film substrate. It is suggested that a hydrophobic silane coating is necessary for reducing the adhesion force between the mold and the substrate leading to a successful printing result.

As the radius, r, of a spherical particle shrinks, the surface/volume ratio, 3/r, and the proportion of its constituent atoms at the surface both increase. The stable interatomic bonding arrangements which exist within large crystals are not satisfied for surface atoms, which therefore become more mobile and more reactive, and nanoparticle properties become dominated by surface properties.

A wide variety of fabrication processes for nanoparticles and related materials has been developed for the last several decades. Cost-effective and environmentally conscious production of nanomaterials is necessary to establish the nanopackaging technology. In addition, shape-controlled synthesis of nanomaterials such as nanorods and nanowires is also important for developing advanced electronic devices. In this chapter, fundamentals and applications of physical and chemical processes are reviewed to understand recent progress in the industrial production for metal nanoparticles and related materials. This chapter also describes utilization of the nanomaterials for preparing electric wires, electrodes, and interconnects.

Nowadays high-k dielectrics are one of the very important materials for capacitors in modern electronics, requiring miniaturization, high performance, and very good stability and functionality, with simultaneous low cost of processing and materials. Usually it is impossible to satisfy all requirements simultaneously; however, different properties can be achieved by application of various technologies, suitable for specified field of application. Thanks to introduction of nanoparticles into composite dielectric material, superior properties can be obtained in comparison to dielectric based on micrometer-sized particles. In this chapter, research and development on high-k polymer for embedded capacitor applications are reviewed and discussed. More specifically, current research efforts toward achieving high-k and low dielectric loss nanoparticle-based dielectric composites are presented. Properties and the long-term stability of capacitors built into PCBs are described. High-k nanocrystalline thin-film layers prepared in various methods are also presented. Brief descriptions of thick-film and ceramic high-k materials with very good reliability and extended operation temperature are included too.

Electronic devices, components, circuits, and systems should be faster, smaller, lighter, and cheaper. Proper functionality of modern electronic circuits demands both active devices and passives (primarily resistors, capacitors, and inductors but also nonlinear resistors – thermistors and/or varistors, potentiometers, etc.). The aim of this chapter is to present the current situation in the area of surface and embedded (buried) resistors made with different microelectronic technologies – thin- and thick-film (TF), low-temperature co-fired ceramics (LTCC), and printed circuit board (PCB). Integrated passive technology is the best for very high component density with increased electrical performance, improved reliability, reduced size and weight, and lower cost. Replacing surface mount devices by embedded passives will lead to the reduction of overall part count, elimination of solder joints, and improvement of wireability and frequency due to elimination of parasitic inductance. The material, technological, and constructional solutions and their relation with the electrical and stability properties chosen are analyzed in detail for modern microresistors, both described in the literature and self-fabricated and/or characterized. The role of such components in modern electronic circuits is also discussed.

Inductors are critical storage components in power converters. Their large size is, however, a major bottleneck for power module integration and efficient power management. High-density inductors can migrate the power converter close to the load. This can lead to lower losses and more efficient and granular power delivery. However, traditional magnetic materials cannot achieve high power density and current handling. Nanomagnetic films provide unique opportunities to enhance permeability, reduce core losses, and integrate inductors close to the chip. Introduction of magnetic anisotropy into the films provides an additional degree of freedom to further enhance current handling. This chapter reviews the fundamentals of nanomagnetic materials and designs for inductor cores with various topologies and illustrates their superiority over traditional materials. Such films can also be applied to RF components for improved inductance density.

Electrically conductive adhesives (ECAs) are composites of polymeric matrices and electrically conductive fillers. Polymeric matrices have excellent dielectric properties and thus are electrical insulators. The conductive fillers provide the electrical properties and the polymeric matrix provides mechanical properties. Therefore, electrical and mechanical properties are provided by different components, which is different from metallic solders that provide both the electrical and mechanical properties. ECAs have been with us for some time. Metal-filled thermoset polymers were first patented as ECAs in the 1950s [1–3]. Recently, ECA materials have been identified as one of the major alternatives for lead-containing solders for microelectronic packaging applications. There are two types of conductive adhesives: isotropically conductive adhesives (ICAs) and anisotropically conductive adhesives/films (ACAs/ACFs).

Display-related electronics such as smartphones, laptops, and UHD TVs have become an indispensable part of our lives. In line with this, as people are demanding images with higher quality, the number of electrical paths from a display driver chip to a display panel is increasing from HD to full HD to UHD and more, resulting in a reduction of the electrode pitch, which is the center-to-center distance between nearby electrodes. The most critical issue facing current display devices is interconnecting the fine pitch driver chips on the display panels using anisotropic conductive adhesives (ACAs) without an electrical short-circuit problems, since conductive particles in the ACAs can be agglomerated between fine pitch electrodes during the ACA bonding process, thereby causing electrical shorts in the X-Y directions. In this paper, a new concept of nanofiber ACAs has been introduced by incorporating conductive particles into nanofibers to suppress conductive particle movement and obtain stable three-dimensional electrical interconnection properties of fine pitch electronics.The novel nanofiber ACAs incorporate conductive particles into conductive particle incorporated nanofiber (CPIN) structures to obtain stable electrical properties of fine pitch display devices. The conductive particle movements during ACA adhesive resin flow are fundamentally suppressed by the CPIN structure fabricated by an electrospinning method. The nanofiber ACAs show superior properties compared with conventional ACAs, providing 2.7 times higher particle capture rate and perfect electrical insulation properties at 20 μm fine pitch interconnections.In addition, the effect of nanofiber material properties on the nanofiber ACA interconnection stability was also investigated in terms of tensile and thermal properties of nanofiber materials. The Nylon 6 nanofiber showed the highest ultimate tensile strength, 19.2 MPa, whereas PVDF and EVOH nanofibers showed values of 16.2 MPa and 9.4 MPa, respectively, with the highest conductive particle capture rate by the Nylon 6 nanofiber. Although the three kinds of nanofiber ACAs showed different capture rates, they all had 100% X-Y axis insulation properties at 20 μm pitch interconnections of chip-on-flex (COF) assembly. The Z-axis contact resistance of all samples rapidly decreased as the nanofibers melted and stabilized at 4~6.4 mΩ above the nanofiber melting temperature.Furthermore, the fine pitch COF assembly using nanofiber solder (Sn3.0Ag0.5Cu) ACAs was also investigated. The nanofiber solder ACAs offer many advantages such as suppressing micro-solder ball movement during ACAs resin flow, perfect X-Y axis insulation at 25 μm fine pitch, 30% lower electrical contact resistance, and excellent unbiased autoclave reliability. Micro-solder balls were successfully incorporated into a nanofiber structure, and they had good solderability within the nanofiber/epoxy matrix. As a result, (Au,Cu)Sn and Cu3Sn IMCs were formed by interfacial reaction of Sn3.0Ag0.5Cu solder balls, Au bumps, and Sn-finished Cu. The continuous IMCs formed in micro-solder ball joints lowered the Z-axis contact resistances and significantly improved moisture resistance compared with the physical contact-based conventional polymer ball ACAs. Therefore, nanofiber solder ACAs can provide an alternative solution for fine pitch interconnections of various electronic assemblies such as COF, COG, and 3D chip stacks.

Electronic packaging provides for mounting and physical support of electronic components, removal of heat from devices (e.g., integrated circuit chips), protection of devices from the environment, and electrical interconnection of components. This electrical interconnection enables distribution of both electronic signals and power throughout the package by means of multiple layers of metal circuit traces. Electrical interconnection between layers (vertically) is typically made with drilled and plated holes.

In modern microelectronics production, additive fabrication processes offer a thematic contrast to traditional micro-fabrication processes that rely critically on subtractive patterning. Printing, a bottom-up process, plays an important role in this production, especially when nanomaterials are printed. There are many areas in which such printing is used [1], but only electrically conductive structures in electronic packaging are the object of interest in this section.

Tin-lead (Sn-Pb) solder alloy has been widely used as interconnection material in electronic packaging due to its low melting temperatures and good wetting behavior on several substrate platings such as Cu, Ag, Pd, and Au. Recently, due to environmental and health concerns, a variety of new lead-free solders have been developed. Lead-free solders lack the toxicity problems associated with lead-contained solders. However, unlike lead solders, the recently employed lead-free solders do not have a long history and manufacturing process, and also board-level reliability has not been established well. Especially, drop test performance is a serious concern for mobile products like cellular phones, cameras, video, and so on. Sn-Ag-Cu alloys are leading candidates for lead-free solders. In this study, it was found that adding Co, Ni or Pt, located to the left of Cu in the periodic table, to SnAg-based solder alloys, did not increase IMC thickness and grain size significantly after the solder reflow process and thermal aging. hence, these nano particles resulted in good drop test performance compared to Cu, Ag, Au, Zn, Al, In, P, Ge, Sb.

Packaging materials undergo dimensional changes under environmental exposure to temperature change. Thermomechanical cyclic loads induce stresses and damage interconnects. Mechanical shock during operation may subject the board assemblies to large out-of-plane deformation. Underfills and potting compounds are often used to enhance the harsh environment reliability of electronics through addition of supplemental restraints to allow for increase in the design margins. The computational tools and experimental test methods for assessing the change in thermomechanical and mechanical shock reliability of fine-pitch electronics with supplemental restraints are discussed. Methods to model the mechanical properties of underfills using unit cell approaches for property prediction and viscoelastic models to capture the constitutive behavior along with experimental measurements of nano-underfills have been presented. The use of explicit finite element models for capturing the transient dynamic response under high-g mechanical shock of unpotted and potted electronics assemblies have been discussed.

A remarkable discovery of graphitic particles in the soot of arc-discharge vessel by Iijima marked the birth of new era in nanoscience – “carbon nanotechnology.” Carbon nanotubes (CNTs) represent a distinct group of nanostructures of relatively few nanometers in diameter and micrometers in length with unique physical and chemical properties. Structurally based on number of graphitic layers, CNTs are classified as single-walled (SWCNTs) and multiwalled (MWCNTs). CNTs offer high surface area, high aspect ratio, and diverse properties with many potential nanotechnology applications. This chapter attempts to explain the bottom-up approach of growing CNTs from primary growth mechanisms to the more sophisticated and modern techniques of controlled chemical synthesis of CNTs. The primary growth parameter that distinguishes the various synthesis techniques is the temperature. This chapter provides advancements in CNT synthesis and characterization based on high-temperature techniques such as the arc discharge, laser ablation and corona discharge methods, and low-temperature chemical vapor deposition techniques.

Carbon nanotubes (CNTs) have evolved into one of the most investigated nanostructures Work function in the last decade for a wide range of applications. CNTs can be identified as helical microtubules of graphene sheets rolled around the chiral vector. The quasi-one-dimensional (1D) structure imparts to CNTs’ unique physical and chemical properties that have naturally led to their use in many nanoelectronic device applications. However, these properties of CNTs are determined by their synthesis methods, and this in turn determines their applicability. Their nanoscale size, unique structure, compositional elements, robustness, and immense surface area for functionalization are a few of the properties which give CNTs interesting prospects to be used in many varied applications. This chapter discusses the classification of CNTs based on their structural and electrical properties along with their fascinating applications in the development of biological, chemical and gas sensors, and field-effect transistors (FETs) and in integrated device fabrication such as memristors.

A novel polymer-based multiwall carbon nanotube (MWCNT) composite with high shielding effectiveness (SE) and effective electromagnetic susceptibility (EMS) performance is proposed for use in packaging a high-speed 2.5 Gbps plastic transceiver module. Both polymer-based dispersed and non-dispersed MWCNT composites are fabricated and then the SE performances are compared. The results showed that the ionic liquid (IL)-dispersed MWCNT composites with 30% weight percentage MWCNTs exhibited high SE of 40–46 dB. By comparison, the MWCNT composites fabricated by a nondispersive process required a higher weight percentage (50%) of MWCNTs. Furthermore, the package housing developed, fabricated by IL-dispersed MWCNT composites, clearly improved EMS performance, mask margin, and power penalty for a 2.5 Gbps lightwave transmission system. This significantly improved result has marked the achievement of using the dispersive MWCNT composites for the high SE and suitability for packaging low-cost and high-performance optical transceiver modules used in the fiber-to-the-home (FTTH) lightwave transmission systems.

Solders are extensively used in electronics packages as mechanical and electrical interconnects because of their ease of processing and low cost. Solder interconnects for wafer-level chip-scale packages are subject to high stresses caused by the mismatch in coefficient of thermal expansion between the silicon chip and the organic substrate when the packages experience changes in temperature during assembly, testing, and field operation. With the relentless trend toward ever-decreasing solder joint pitches and sizes, these thermomechanical stresses will increase exponentially, and there is a need to enhance the strength of the current solder materials to withstand the increased stresses. This chapter describes a study on the usage of single-walled carbon nanotubes (SWCNTs) as a reinforcing material for the enhancement of the solder material properties for use in wafer-level chip-scale packages. The aim of this work is to fabricate CNT-reinforced nanocomposite solders; characterize their improved physical, thermal, electrical, mechanical, and wetting properties; and compare them to the original Sn-Pb and Sn-Ag-Cu solders.

In the light of continuous miniaturization of traditional microelectronic components, the demand for decreasing wire diameters becomes immediately evident. The observation of metallic conductor properties for certain configurations of carbon nanotubes (CNT) and their current-carrying capability [1] sets the minimal diameter of a “true” wire to about 3 nm (compare Chap. 18 ). Investigations are in progress even below that diameter on nanocontacts, formed by single metal atoms, i.e. quantum wires. Quantum wires can be produced by mechanical wire breaking [2] or its combination with etching and deposition [3] or other techniques. The properties of quantum wires are only about to be understood theoretically [4]. Doubtless, they are worth considering for packaging solutions in molecular electronics to come [5]. In this chapter we focus on metal wires and rods in the size range above 10 nm up to submicron diameters, evaluated already to be attractive for microelectronic packaging purposes. Techniques to generate, to characterize and to handle them, as well as their interaction with electromagnetic fields will be useful for packaging applications in the age of nanotechnology. With the wealth of information available, this review focuses on general trends and starting points for deeper study. Although the cited references are representative, they cannot be complete, since numerous activities are still ongoing to produce and to characterize new kinds of wire-like geometries from different materials.

Advanced microelectronic packaging, driven by the multiple benefits of system performance, power, size and cost, has moved into a three-dimensional (3D) era. One of the bottlenecks to 3D IC integration is the high-density interconnections to be formed between stacked dies. Prevailing solder-based interconnect encounters constraints including high process temperature, increasing process cost and intermetallic compound (IMC) reliability issues related to the ever-decreasing pad/pitch size. Anisotropic conductive film (ACF) and anisotropic conductive adhesive (ACA) technology are two of the fine-pitch, low-temperature flip-chip material bonding options, which have been considered as potential replacements for solder interconnections. However, conventional ACF or Anisotropic conductive paste (ACP) with spherical conductive particles have limitations in terms of unpredictable numbers of trapped particles in the interconnections and the occurrence of particle agglomeration in the small gaps between interconnections. To tackle these limitations, a nanowire ACF (NW-ACF) with vertically configured, high aspect ratio metallic nanowires has been fabricated utilizing a nanoporous template and an electrodeposition method to create a novel nano-ACF material. The NW-ACF has been structurally and electrically characterized to demonstrate its feasibility as a fine-pitch and low-temperature interconnection solution for future 3D die-/wafer-level interconnection applications.

This chapter provides a comprehensive review of the state of the art of carbon-based interconnects, presenting the most relevant results in modeling, fabrication, and integration.Due to their outstanding electrical, thermal, and mechanical properties, carbon-based materials such as carbon nanotubes and graphene nanoribbons have been proposed as candidates for realizing electrical interconnects, to overcome the limits foreseen at nanoscale for conventional materials like copper. Extensive consideration has been so far devoted to this emerging interconnect technology, with a huge effort spent in theoretical and experimental works aimed at demonstrating its feasibility.Simulation results opened the door to the promise of a real technological breakthrough, characterized by fascinating properties like electrical and thermal ballistic transport, reduced delay, insensitivity to skin effect, mitigation of electromigration, thermal stability, and enhanced reliability and resiliency. These results suggest using carbon materials to fabricate all types of interconnects for future nanoscale VLSI circuits, on-chip signal and power interconnects, through-silicon vias, chip-to-package interconnects, and so on.In practical applications, these promising results are strictly related to the possibility of realizing high-quality carbon interconnects, with a satisfactory control over parameters like chirality, density, alignment, defects, surface roughness, and contacts. Therefore, major efforts have been made in the last years to assess reliable design approaches and effective fabrication processes. Although technological solutions have been demonstrated to solve issues like the compatibility of the growth temperature with the standard CMOS technology, the needed density and degree of alignment, the presence of defects, and the contact quality, these solutions are still not suitable for a mass production, and so the route to the industrial exploitation of this emerging technology is still long.

One important function of electronics packaging is to remove the heat generated by the integrated circuits (ICs). Efficient cooling requires both high heat conduction within the package and efficient heat removal from the package. Elevated temperature is damaging to the chip and its package. Material mismatch causes mechanical stress leading to fatigue, creep, and finally failure; interconnects can melt, and electromigration within the IC is speeded up. Efficient heat removal is not always the case. Plastics is a common packaging material as it is electrically insulating and cheap. The thermal conductivity is, however low, about 0.2 W/mK compared to that of metals (aluminum 220 W/mK and copper 400 W/mK). Other important factors are the heat spreading and thermal interface materials. The components are often mounted on a polymer board which is only cooled by air. The heat transfer coefficient is only 5–15 W/m2 K for natural convection and 15–250 W/m2 K for forced convection in gases [1].

Graphene is a two-dimensional, atomic-scale, and sp2-hybridized carbon with unique and excellent optical, mechanical, and electric properties which have attracted a lot of attention for a broad range of applications. In this chapter, methods of synthesizing, processing, and transferring graphene onto desired substrates for applications are explained. Synthesis of transfer-free graphene and convenient means of evaluating the quality of synthesized graphene are discussed.

Graphene is a two-dimensional material which is composed of a honeycomb lattice made of single atomic layer of carbon atoms arranged in a hexagonal atomic structure. It has many extraordinary properties desirable for real-world applications. Low electrical resistivity, high electromigration resistance, high thermal conductivity, and outstanding mechanical strength make graphene a promising candidate for nano-interconnects. The atomically thin graphene is also optically transparent in a wide spectrum of wavelength and an excellent diffusion barrier. In this chapter, characterization of graphene for electronic, electrical, optical, and mechanical applications is discussed.

Development of the next generation of micro- and nanoscale electronics requires efficient thermal management. As the dissipated power density increases, heat removal becomes a critical issue. This motivates researchers to investigate and synthesize materials that can drastically improve thermal management of electronic devices. The discovery of the exceptionally high thermal conductivity of graphene has led to significant progress in thermally conductive coatings and thermal interface materials. In this chapter, we review recent progress in graphene applications for thermal management, focusing on graphene laminates, reduced graphene oxide films, and graphene fillers in composite materials.

Power and latency are fast becoming major bottlenecks in the design of high-performance microprocessors and computers. Power relates to both consumption and dissipation, and therefore, effective power distribution design and thermal management solutions are required. Latency is caused by the global interconnects on the IC (integrated circuit) that span at least half a chip edge due to the RC (resistance-capacitance) and transmission line delay [1]. Limits to chip power dissipation and power density and limits on hyper-pipelining in microprocessors threaten to impede the exponential growth in microprocessor performance. In contrast, multi-core processors can continue to provide a historical performance growth on most consumer and business applications provided that the power efficiency of the cores stays within reasonable power budgets. To sustain the dramatic performance growth, a rapid increase in the number of cores per die and a corresponding growth in off-chip bandwidth are required [2]. Thus, it is projected by the Semiconductor Industry Association in their International Technology Roadmap for Semiconductors (ITRS) that by the year 2018, with the IC node size shrinking to 22 nm by 2016 and 14 nm by 2020, the chip-to-substrate area array input-output interconnects will require a pitch of 70 μm [3]. Furthermore, to reduce the RC and transmission line delay, low-K dielectric/Cu and ultra-low-K dielectric/Cu interconnects on silicon will become increasingly common. In such ICs, the thermomechanical stresses induced by the chip-to-substrate interconnects could crack or delaminate the dielectric material causing reliability problems (Table 28.1).

Metal nanoparticle applications are proliferating in nanoelectronics, e.g., in single-electron transistors, and in nanoelectronics packaging, e.g., with the introduction of nanoparticle nanocomposites, carbon nanotubes, nanoparticle conductive inks and vias, and underfill fillers. Nanosensors comprise a major segment of the new nanotechnology developments, and there are opportunities to exploit some of these concepts and devices in electronics package diagnostics and reliability prognostics. This chapter concentrates on two potential applications of one basic type of sensor structure (a metal nanodot array) for corrosion detection (by hydrogen sensing) and strain monitoring.

Nanotechnology, the science aiming at manipulating matter at nanometer scale, has advanced tremendously. Bio-nanotechnology indeed analyzes and seeks to apply biological principles and structures at nanoscale for various technological uses. But how can bio-nanotechnology aid in electronic packaging, a field comprising well-established technologies that once implemented give rise to various electronic products such as smartphones, tablets, or medical devices?Assembly is one of a major technology in electronic packaging that is needed to build up functional electronic devices. At the nanoscale, this is most effectively accomplished by self-assembly, a process that is successfully utilized in nature to produce genuine machines and assemblies that power and direct proper functioning of living cells.This chapter discusses some of nature’s examples of extraordinary self-assembly and reflects upon how and what modalities and opportunities might exist that would inspire for extending electronic packaging technologies to nanoscale assembly in the future. Following a miniaturization trend, MEMS devices that require special packaging and assembly technologies would most probably benefit.

Semiconductor devices reached the nanoscale in the 2000s and have continued to shrink their features in accordance with Moore’s law. Semiconductor packaging, which is critical to ensure connectivity of these fine-featured semiconductor devices, has also kept pace with Moore’s law scaling to enable products to take advantage of the performance scaling opportunities afforded by silicon scaling. In doing so, packaging has been increasingly challenged to provide requisite interconnect scaling, form-factor scaling, process scaling, enhanced thermal management, improved signal integrity, improved power delivery, and adequate thermomechanical reliability in increasingly diverse applications. This chapter systematically examines the evolution, challenges, and opportunities of different aspects of flip-chip package scaling, typically used for high-performance silicon. Materials continue to play a critical role in the evolution of flip-chip packaging, and their influence and impact are also discussed to highlight their contributions and importance.

This chapter focuses on the environmental, health, and safety (HSE) aspects of nanotechnology and nanomaterials. The HSE aspect of nanomaterials is gaining more visibility, and organizations will be required to address the needs of both people and the environment. The fact that various nanomaterials are more reactive than their bulk counterparts creates a need to address the possible effects, which are typically unknown, in working with, handling, storing, applying, manufacturing, and creating novel combinations of nanomaterials. This chapter provides an overview of some of the characteristics of known nanomaterials, identifies known effects on people and the environment, and addresses the need and method of proper handling of nanomaterials. There are methods to be implemented to address current and possible future concerns. Education is critical to the proper and safe handling of nanomaterials.Nanomaterials are being introduced into more aspects of everyday products. The application of novel materials, which have properties that are not fully known, into packaging raises the question of “what are the impacts of the application of these materials on people’s health, overall safety, and long term impact on the environment.” This chapter provides a short review of the possible material effects. The key to safe application of nanomaterials is the development of a program and process that ensures steps are taken to minimize risks and control materials. This chapter also provides links to sources of regulatory agencies and other organizations that continually track the latest developments in nanomaterial investigations.