CE is a fast clockspeed sector, i.e., new products are being introduced at a high rate […] Accompanying the frequent introduction of new products is the rise of E-waste […] To dump perfectly good products means throwing away value, which now WEEE gives the chance to manufacturers and importers to recover.
In the case of CE and IT equipment there is evidence to indicate that many ignitions occur from external ignition sources.9 While these have not traditionally been the domain of fire safety standards they have now become a major focus in the standardisation work being undertaken by IEC TC108 (Safety of electronic equipment within the field of audio/video, information technology and communication technology) who are in the process of producing a single performance-based safety standard for CE and IT equipment. This standard recognises the importance of external ignition in many CE and IT products and has expanded the scope of the proposed standard to include external ignition from small open flames. In this context they refer specifically to accidental ignition from candle flames although the logic could be expanded to include other small open flames such as matches and lighters in the hands of juvenile fire setters.
There are very few successful commercial applications of NPs. Utilization of catalytic properties of metallic NPs in fuel cells and petrochemistry provides rare examples of commercial success. However, there are hundreds of other potential applications at different stages of market development. Prototype and pilot plant demonstrations have been reported in energy, biomedical, optoelectronics, and environment sectors.
Optoelectronics including consumer electronics, pharmaceutics, cosmetics, catalysis, batteries, and chemicals constitute the backbone of the NP market. Some specific applications on the market or under development include :
Energy: Pd NPs for automotive catalyst; TiO2-based dye-sensitized solar cell;
Environment: TiO2-based photocatalyst; magnetic NPs for remediation; catalytic converters;
Microelectronics: Al2O3-based chemical-mechanical polishing; magnetic NPs for electromagnetic interference (EMI) shielding; metal NPs for conductive patterns;
Biomedical: NP-based drug delivery; magnetic NP-based magnetic resonance imaging;
At this stage, it is important to distinguish hype (long term) from reality (short term). NP fabrication and integration into commercial products is part of a new industry . Based on laboratory and pilot plant demonstrations, a large number of NP-enabled products will be commercialized in the future. Three large industries in which NPs already have or will have a significant impact have been identified:
Manufacturing, including NP-based material production and integration for transportation and packaging. Some manufactured products are already in the market although with relatively slow market penetration;
Optoelectronics, with some commercial products to be developed in the medium term. Once successful, a very fast market penetration is expected in this sector;
Life sciences, where a more long-term development is expected with rapid market penetration afterwards.
Low risk and low rewards, medium risk and medium rewards, and high risk and high rewards are expected for those investing in the manufacturing, electronics, and life science sectors, respectively.
The market for consumer electronics (brown goods) and appliances (white goods) is expected to grow at CAGR of 13% from FY2005 to FY2020, with sector revenues rising nearly seven-fold from 3.5 billion USD in 2005 to 20.6 billion USD in 2020. A growing middle class, with rising disposable incomes and facilitated access to credit, as well as a large rural population increasingly connected to the electricity grid, are demand drivers for new and used gadgets. Currently, urban consumers account for approximately two-thirds of the total sales of electronic and electrical products, and this demand is expected to increase with growing urbanization. In addition, there is a large unmet demand in rural areas, especially for products such as refrigerators and TVs. Currently only 8% of rural households own refrigerators and 41% in urban areas; rural households have higher ownership of TVs at 44%, however, still lower than urban households with 77% penetration rate (Prayas Energy Group, 2012).
With government policy to provide energy access to all, and the development of the solar off-grid sector, there is an increasing demand for appliances, which are expected to make India the fifth largest consumer durables market in the world by 2025.
Parallel to the greater demand for electrical and electronic equipment (EEE), there is also a rapidly growing waste electrical and electronic equipment (WEEE) or e-waste stream. Various studies have put different figures on the amount of WEEE generated in India (Table 20.1). While there may be differences in the absolute values, depending on the methodology for estimation as well as the scope of the products included in the estimate, the one consistent trend is the increase in WEEE generated over the years, since the first assessment was made in 2004 as part of a Swiss-funded E-waste project (Empa, 2004).
Table 20.1. Estimates of quantity of e-waste generated for India from various sources
WEEE generated (million tons/year)
Based on tracer method; only for PCs
Based on obsolescence rate and installed base assumptions
Includes computers, mobiles, televisions, and imports
Includes large household appliances and others
Compiled from multiple sources of data; includes computers, printers, mobile phones, televisions, refrigerators
Includes large household appliances and others
Based on obsolescence rate and installed base
Uses 0.8 million tons in 2012 as the base; projections up to 2019 based on a cumulative annual growth rate of 27% between 2008 and 2012 and 21% between 2014 and 2019
Frost and Sullivan (2015)
Based on sales determination and extrapolation of the data;
UN Monitor (2014)
1.3 kg per capita e-waste generation rate
Uses 0.8 million tons in 2012 as the base; projections up to 2019 based on a cumulative annual growth rate of 27% between 2008 and 2012 and 21% between 2014 and 2019
Frost and Sullivan (2015)
Based on sales determination and extrapolation of the data and including imports
UN Monitor (2017)
Estimates of e-waste generation quantities for India from various sources.
29.4.2 What went wrong with the WEEE Directive? What are the avenues for improvement?
In the opinion of PCE two things went basically wrong with the WEEE Directive:
Lack of a clear goal setting. Basically, the two goals are recycling and control of toxics. In the initial version of WEEE emphasis was on toxic control. Soon this changed to recycling in view of the preparation of a separate Restriction on Hazardous Substances (RoHS) Directive. However, particularly the exemptions in RoHS mean that there is a ‘gap’ which is not closed by the Annex II for treatment of toxics in WEEE. Depending on the product group, the two goals have different priorities: toxic control for fridges/freezers (CFCs), LCD TVs and monitors (mercury in backlights), recycling for telecom and other miniaturized products (precious metals), metal dominated products (metals), whereas other categories (for instance CRT containing products, most plastic dominated products) have a ‘mixed priority’. Whatever the precise priority is, this situation calls for differentiation in requirements as regards collection, treatment and dealing with secondary streams.
Attributing responsibilities. It is a societal interest to realize the goals as formulated above at the lowest cost (for society). In the end citizens have to pay directly or indirectly for take-back and treatment and generally speaking they are prepared to do so provided that there is environmental value for money. Therefore there is a logic in attributing responsibilities in the end-of-life chain to those actors which can achieve the best environmental gain (either in terms of recycling or in toxic control over cost ratios). The best ratios will be scored by those actors which will have the most capability and power to influence the outcomes to the positive. Experience has shown that technical and financial responsibility should coincide. If this is not the case, either take-back systems do not work optimally or cost a disproportional amount of money.
The fact that these two fundamental issues have not been properly addressed meant that member states had to find their own way out during the implementation. While the Directive was still under discussion, a lot of practical experiences (see for instance Section 29.3.1) and science-based input (see for instance Section 29.3.3) could have contributed to improvement of the draft Directive ‘on the fly’. Little of this has been taken into account and therefore the EU ended up with an ‘old-fashioned’, 1995 style Directive. It is hoped that the WEEE Recast (see Chapter 2) will improve the situation.
In the meanwhile member states are struggling with the implementation. A summary of the chief issues is given by Huisman et al. (2006). Improvement agendas for short term, medium term and long term within the present Directive are given by Huisman and Stevels (2004). Options for further development and simplification of WEEE are given by Magalini et al. (2006).
The proposals in these papers consider:
definitions and clarification of goal setting (making more clear what is really meant, scope/boundary issues);
administrative items (simplification at the front end, better monitoring at the back end);
technical items (collection, treatment, upgrading of secondary streams, toxic control);
financial items ((in) adequacy of fees, guarantee issues, opt-out conditions in collective systems);
organizational items (‘put on market’/who is a producer, no distinction between B2B and B2C, enforcement).
In view of the dynamics of take-back it is proposed to introduce a general ‘environmental equivalence rule’. This means that any action for which it can be demonstrated that it is better from an environmental perspective than the current implementation practice is to be accepted. It is hoped that the Recast of WEEE (see Chapter 2) will create a strong basis for enhancing the effectiveness of the WEEE Directive.
Driven by environmental programs across the consumer electronics industry, portable electronics product manufacturers are opting for light, yet tough, magnesium for everything from ﬂash audio/video players to digital cameras, mobile phones, computer notebooks, radar detectors and more. Magnesium meets the design challenges that are instrumental to consumer electronics becoming lighter, thinner and more mobile. Components that house and protect highly sensitive technology inside these entertainment and communications devices must exhibit strength and durability to withstand daily abuse from being dropped, stepped on, bumped, banged around in transit, and survive even the ultimate test – teenagers. Figures 8.27–8.30 show magnesium applications in casings for audio/video players, cameras, cell phones and laptop computers.80
Information and communication technologies; consumer electronics including toys; large household equipment, such as dishwashers and washing machines; medical equipment; and electric tools have become central to our daily lives. People are enjoying what technology provides, surfing the Internet, buying daily merchandise on their smart phones or tablets and watching high-definition movies on their televisions at home. As more and more electronic products are produced to satisfy the demands worldwide, more resources are used to produce these items. Hence, a rapid growth of computing and communication equipment is driving the ever-increasing production of electronic waste (e-waste). As observed by the United Nations, there is a presence of a global inconsistency in the understanding and application of the term “e-waste” in both legislation and everyday use. This had repercussions in the form of many definitions contained within e-waste regulations, policies and guidelines. The term “e-waste” itself is self-explanatory, in the sense that it is an abbreviation of “electronic waste”. A key part of the definition is the word “waste” and what it logically implies – that the item has no further use and is rejected as useless or excess to the owner in its current condition.
“E-waste is a term used to cover items of all of electrical and electronic equipment (EEE) and its parts that have been discarded by the owner as waste without the invention of re-use” (One Global Definition of E-waste, 2014).
The act of discarding an EEE as e-waste is considered when the owner decides the item is no longer useful to them due to any kind of failure, technical capability, cosmetic condition, age, replacement, organizational policy, depreciation, etc. The word “discard” is defined in the Merriam Webster dictionary as “to throw (something) away because it is useless or unwanted”, and in the Cambridge Dictionary as “to throw something away or get rid of it because you no longer want or need it”. There are none requisites for the equipment to be non-functional, to be designated as e-waste by the owner, as it is solely the owner’s discretion, if they so decide.
The worldwide thirst for portable consumer electronics in the 1990s has had enormous impact on the field of portable power sources. During this era, lithium-ion batteries, which are based on having lithium ions shuttle between an insertion cathode and an insertion anode, emerged as the rechargeable power source for several lucrative portable electronics markets, including laptops and cell phones. The need for portable power is not diminishing. Moreover, with the continued miniaturization of electronic devices and the development of microsystems, there is considerable concern as to how future portable power systems will shrink to the dimensional scale of the device.
For the most part, batteries based on traditional designs have not been very successful at reducing size and still being able to provide adequate power and energy for portable electronics applications. The limitations faced in miniaturizing batteries are perhaps best shown by considering rechargeable lithium-ion batteries whose usage is ubiquitous. Lithium-ion batteries use insertion processes for both the positive and negative electrodes, leading to the term ‘rocking chair’ battery. The transport of lithium ions between the electrodes, usually arranged in a parallel-plate configuration, is one-dimensional (1-D) in nature. To minimize power losses resulting from slow transport of ions, the thickness of the insertion electrodes, as well as the separation distance between them, is kept as small as possible. This approach may appear counterintuitive in the effort to produce a useful battery because reducing the thickness of the electrode results in lower energy capacity and shorter operating time. Thus, battery design involves a compromise between available energy and the ability to release this energy without internal power losses.
Miniaturization of secondary lithium-ion batteries has been largely focused on thin-film configurations. This approach represents an extension of traditional 2-D battery designs and layer-by-layer construction of the cell. The anode, separator/electrolyte, and cathode are stacked, spiral wound, or folded in lithium-ion batteries, preserving the essential 2-D nature of the device. Thin-film batteries exhibit excellent energy density, ∼2 J mm−3. However, in order to reach this level, they require a significant amount of area, generally above a few square centimeters because of their 2-D design. As a result, thin-film batteries have relatively poor energy density, less than the 1 mWh cm−2 range, because the thickness of the cathode is limited to just a few micrometers due to stress generation and fracture. Thus, while typical rechargeable thin-film lithium batteries can provide milliwatt levels of power, they can only do so for a few minutes unless they take up a very large area.
The reason for the interest in device area is that the miniaturization occurring in the electronics field generally results in the device requiring progressively less area. Correspondingly, there is less area available for the power source. Whereas a decade ago the area available for the power source was a few square centimeters, it is now a few square millimeters. A recent analysis of the power needs for distributed sensor network systems showed that when only a few square millimeters of area is available for the power source, the energy that could be supplied by thin-film lithium batteries was 100 times below the level required for autonomous operation of the sensor network. This example underscores a critical issue concerning all small power device designs and their ability to be integrated onboard the device: In order to power miniaturized electronic devices which have limited real estate, batteries must somehow make good use of thickness.
Three-dimensional batteries have been proposed as a new direction for miniaturizing portable power sources. The 3-D configuration makes use of the out-of-plane dimension in contrast to traditional battery electrodes, which use only the in-plane surface. The use of the ‘vertical’ dimension provides a design option that enables the battery to have a small areal ‘footprint’. Therefore, 3-D battery designs should be more readily integrated with miniaturized devices. Another benefit of 3-D architectures is the prospect of achieving high power density from maintaining a short ion diffusion length between anode and cathode and from high electrode surface area.
A brief comparison between the conventional 2-D parallel-plate design and the 3-D array cell (Figure 1) is able to illustrate the advantages of the 3-D architecture. In the interdigitated design, the 3-D battery has a lower energy capacity per total cell volume than that of the 2-D battery. However, the capacity of the 3-D design can be increased by increasing L, the length of the electrode rods, without sacrificing the small areal footprint or high power density. Clearly, L cannot be increased without limit as the ohmic resistance of the electrodes will become progressively larger and offset the advantages of increased areal capacity. The optimized value of L will be determined by a combination of parameters including the electronic conductivity of the electrode materials, the ionic conductivity of the electrodes and electrolyte, and the specific electrode geometry.
In this article, we describe the different configurations proposed for 3-D batteries and the progress to date on fabricating electrode structures and materials. The final section reviews the initial results obtained for this new generation of batteries.
The seemingly endless pursuit to miniaturize consumer electronics and pack more functionality into them has led to the commercialization of mesoscale (order of 10 cm) fans to cool high-powered chips. However, there are no commercial fans currently available that are small enough to cool very small, portable, high-powered electronic devices. Laptops now use small axial fans to cool microprocessors with integrated heat sinks attached to the chip casing. However, these fan and heat sink combinations are not sufficient to cool more powerful microprocessors that are used in desktop systems that require more powerful fans, heat pipes, and even active cooling systems to enable their use. The miniaturization effort for axial flow fans faces limitations due to two main reasons: difficulty in fabrication and an unfavorable trend in the aerodynamic performance of the fan. Grimes et al. (2003) investigated the issues of scaling of microfans by fabricating a series of geometrically similar 3D microaxial flow fans with representative sizes (120, 40, and 6 mm of fan diameters, d) and quantifying the performance of the fans in terms of entropy generation. They used micro electrodischarge machining (µEDM) to fabricate the smallest fan tested that had a 6-mm diameter and a 25-µm blade tip clearance. They did not use silicon MEMS technology, with which it is difficult to produce 3D shape of the blades.
In general, a reduction in size of a fan results in a reduction in its efficiency, which is caused by a relative increase in entropy generation (Massey, 1983). Further analysis showed that there is a larger increase in the local entropy generation rate as the diameter is reduced (~d−1/2) in the laminar boundary layer than the entropy generation rate in the turbulent boundary layer, which is only weakly inversely dependent on the length scale (~d−1/7) (Grimes et al., 2003). Since laminar flow dominates with microscale fans, their efficiency and performance become poorer as the diameter of the fan is reduced. Recently, the same group from the University of Limerick reported similar aerodynamic disadvantages for micro radial flow fans fabricated by stereolithography as the fan size is reduced below 10 mm (Hanly et al., 2005). They also investigated the integration of the microfans into low-profile portable electronics (Walsh and Grimes, 2006). Figure 2 shows a micro radial flow fan made using stereolithography, and the copper heat sink with a center hole that the fan is inserted into. On spinning, cooler air is drawn by the fan across the evenly spaced radial fins, and the subsequently heated air is exhausted.
Along with the penalty that smaller fans run at a lower efficiency than larger fans, acoustic noise generated by a microfan is another important issue. As the heat flux from the electronic devices increases, the fan has to run at a higher rotational speed, and vibrational noise is typically proportional to the harmonics of rotational speed and the tip-to-edge distance per unit volumetric flow rates. Typically, if the radius of the radial fan is decreased one order of magnitude, the rotational speed needs to increase one order of magnitude to maintain the same volumetric flow rate per unit of planform area. Also, it is often difficult to proportionally decrease the tip-to-edge distance when reducing size. Therefore, both the rotational speed and the bypass tip flow rate, which is a major source of noise and losses, are higher. Of course, the smaller size reduces the overall magnitude. However, it can be hard to control the noise level, particularly at higher frequencies. Similarly, the power consumption per unit volumetric flow rate also typically increases with the rotational frequency squared. Thus, smaller-size systems may consume more power for a given cooling power needed.
Applications of magnetic materials in industry and consumer electronics have increased continuously. The ideal material is one with a large magnetic moment at room temperature, which is also an electrical insulator. Ferromagnetic metals and alloys have been widely exploited, but their low electrical resistivity (10−7 Ωm) is a large problem in radio-frequency applications because of the eddy-current losses. For this reason a number of magnetic oxides have become of great technical interest because of their high electrical resistivity (1–106 Ωm). Magnetic oxides show spontaneous magnetization, remanence, and other properties similar to ordinary ferromagnetic materials, but the spontaneous moment does not correspond to the value expected for full parallel alignment of the dipoles. In 1948 Néel put forward a theory for such materials; he suggested that they contain two sublattices in which the magnetizations are oppositely directed, but which give a net moment because the two sublattice moments are unequal. For this phenomenon he coined the word ferrimagnetism. About the same time that Néel was developing his theory, Snoek was obtaining very interesting properties in a new class of oxide materials called ferrites that were very useful at high frequencies. The arrangement of the ions of the crystal structure of the ferrite will play a most important role in determining the magnetic interactions, and therefore, the magnetic properties.
Electronic control units, power modules, and consumer electronics are used today in a wide variety of varying climatic conditions. Varying external climatic conditions of temperature and humidity can cause an uncontrolled local climate inside the device enclosure. Uncontrolled humidity together with a number of other factors including the presence of hygroscopic contamination resulting from the Printed Circuit Board Assembly (PCBA) manufacturing process can introduce deviation from desired functionality or even intermittent or permanent failure of the device. Additional factors are the miniaturization and high density packing combined with the use of several materials, which can undergo electrochemical corrosion in the presence of water film formed due to humidity exposure and bias conditions on the PCBA surface. This article provides a short review of the corrosion reliability issues of electronics due to the use of electronics under varying humidity conditions. Important PCBA aspects, which are fundamental to the corrosion cell formation under humid conditions, are discussed. Effect of hygroscopic residues from the process and service and their role in assisting water film build up and corrosion is presented. Various failure modes resulting from the corrosion and influence factors are discussed including humid and gaseous conditions.