Green Ideas Starts With Green Computing
Green Ideas Starts With Green Computing
Nowadays Computer play a vast role in our daily life. Many organizations try to restrict on using hazardous substances like in electrical parts of computer, not just banning hazardous substances but also making electrical products as energy efficient without compromising performance.
Energy efficient machines are very important nowadays due to rising of fuel cost used to generate electricity. Nowadays cooling is playing a vast role to electronic products especailly in the processor, processors generate excessive heat when under heavy loads and heavy loads is equal to higher energy consumption, nowadays electronic manufacturers are trying to make to computers energy efficient like DELL corporation.
Making electronic products clean is not an easy to achieve, I think its very hard to make it hazardous free while maintaining its features, So some Companies are just trying to reduce it, Like AMD said:
“Although lead containing solder cannot be completely eliminated from all applications today, AMD engineers have developed effective technical solutions to reduce lead content in microprocessors and chipsets to ensure RoHS compliance while minimizing costs and maintaining product features. There is no change to fit, functional, electrical or performance specifications. Quality and reliability standards for RoHS compliant products are expected to be identical compared to current packages.” Source: http://www.wikipedia.com/
Computers nowadays are not just energy efficient but also reducing its hazardous substances in its electronic parts, One of the organizations who tries to restrict hazardous materials is RoHs(Restriction on Hazardous Substances). Because of their effort, many Electronic companies tried to follow their footsteps on green computing. RoHs compliant Companies brought our technology to the next level, not just making them less hazardous but also making it energy efficient without compromising the performance. Electronic companies does not exactly removes all hazardous substances because there are still hazardous substances that is very important to electronic hardwares, Many scientist today are still inventing or researching to replace hazardous substances without compromising the performance.
Based on Wikipedia
Reliability Concerns:
An illustration of solder joint reliability, demonstrating AlphaSTAR’s reliability versus traditional joints. AlphaSTAR is a RoHS immersion silver PWB assembly process from Cookson Electronics. Copyright 2007 © Enthone Inc. Contrary to the predictions of widespread component failure and reduced reliability, RoHS’s first anniversary (July 2007) passed with little fanfare. Today, millions of compliant products are in use worldwide. Some of the most popular consumer electronics are now RoHS compliant, examples include Apple’s iPod portable music players, Dell and HP home computers and servers, and Motorola’s RAZR wireless phones. Many electronics companies keep “RoHS status” pages on their corporate websites. For example, the AMD website states: “Although lead containing solder cannot be completely eliminated from all applications today, AMD engineers have developed effective technical solutions to reduce lead content in microprocessors and chipsets to ensure RoHS compliance while minimizing costs and maintaining product features. There is no change to fit, functional, electrical or performance specifications. Quality and reliability standards for RoHS compliant products are expected to be identical compared to current packages.”RoHS printed circuit board finishing technologies are surpassing traditional formulations in fabrication thermal shock, solder paste printability, contact resistance, and aluminum wire bonding performance and nearing their performance in other attributes. One of these finishing products, known as immersion silver, is depicted here. The properties of lead-free solder, such as its high temperature resilience, has been used to prevent failures under harsh field conditions. These conditions include 150°C operating temperatures with test cycles in the range of -40°C – 150°C with severe vibration and shock requirements. Automobile manufacturers are turning to RoHS solutions now as electronics move into the engine bay.
Flow properties and assembly One of the major differences between lead-containing and lead-free solder pastes is the “flow” of the solder in its liquid state. Lead-containing solder has higher surface tension, and tends to move slightly to attach itself to exposed metal surfaces that touch any part of the liquid solder. Lead-free solder conversely tends to stay in place where it is in its liquid state, and attaches itself to exposed metal surfaces only where the liquid solder touches it.
This lack of “flow” — while typically seen as a disadvantage because it can lead to lesser quality electrical contacts — can be used to place components tighter than they normally could be placed due to the properties of lead-containing solders. For example, Motorola reports that their new RoHS wireless device assembly techniques are “…enabling a smaller, thinner, lighter unit.” Their Motorola Q phone would not have been possible without the new solder. The lead-free solder allows for tighter pad spacing
Some exempt products achieve compliance Research into new alloys and technologies is allowing companies to release RoHS products that are currently exempt from compliance, e.g. computer servers.[ IBM has announced a RoHS solution for high lead solder joints once thought to remain a permanent exemption. The lead-free packaging technology "...offers economical advantages in relation to traditional bumping processes, such as solder waste reduction, use of bulk alloys, quicker time-to-market for products and a much lower chemical usage rate." Test and measurement vendors, such as National Instruments, have also started to produce RoHS-compliant products, despite devices in this category being exempt from the RoHS directive. Source:
http://www.wikipedia.com/
Health benefits RoHS helps reduce damage to people and the environment in third-world countries where much of today's "high-tech trash" ends up. The use of lead-free solders and components has provided immediate health benefits to electronics industry workers in prototype and manufacturing operations.
Contact with solder paste no longer represents the same health-hazard it did before. Source: http://www.wikipedia.com/
Criticism:
Criticism Adverse effects on product quality and reliability, plus high cost of compliance (especially to small business) are cited as criticisms of the directive, as well as research indicating that the life cycle effect of lead-free solder is more significant than that of traditional solder materials.[citation needed]One criticism of RoHS is that the restriction of lead and cadmium does not address some of their most prolific applications, while being costly for the electronics industry to comply with. Specifically, the total lead used in electronics makes up only 2% of world lead consumption, while 90% of lead is used for batteries (covered by the battery directive, as mentioned above, which requires recycling and limits the use of mercury and cadmium, but does not restrict lead). Another criticism is that less than 4% of lead in landfills is due to electronic components or circuit boards, while approximately 36% is due to leaded glass in monitors and televisions, which can contain up to 2kg per screen. Restricting lead content in solder for electronics requires expensive retooling of assembly lines and different coatings for the leads of the electronic parts. Lead-free solders have a higher melting point requiring higher process temperatures (e.g., a 30°C typical difference for tin-silver-copper alloys), driving changes to materials for chip packages, for some printed circuit boards and components containing plastics. The higher temperature also precludes the use of components designed for lower temperatures.
Interestingly, because these lead-free solders are less susceptible to high temperature failures, the automobile industry has used them to their advantage for years now, see the pros section. Lead-free solders are significantly harder, which can increase the likelihood of cracks instead of plastic deformation, which is typical for lead-containing solders. Such cracks occur due to thermal or mechanical forces acting on components or the circuit board, the former being more common during manufacturing and the latter in the field.The editor of Conformity Magazine wonders if the transition to lead-free solder will not affect long-term reliability of electronic devices and systems, especially in applications more mission-critical than in consumer products, citing possible breaches due to other environmental factors like oxidation. This article refers to the Newark InOne “RoHS Legislation and Technical Manual”, which cites these and other “lead-free”
solder issues, such as: Warping or delamination of printed circuit boards; Damage to through-holes, ICs and components on circuit boards; and, Added moisture sensitivity, all of which may compromise quality and reliability.
Effect on reliability Admission of reliability problems is found in Annex, item #7, of the RoHS directive itself, granting servers exemption from regulation until 2010. It should be noted that these issues were raised when the directive was first implemented in 2003 and reliability effects were less known.
Another problem that lead-free solders face is the growth of tin whiskers. These thin strands of tin can grow and make contact with an adjacent trace, developing a short circuit. Research has also identified a particular failure mode for tin whiskers, where in high power components a short circuiting tin whisker is ionized into a plasma that is capable of conducting hundreds of amps of current, massively increasing the damaging effect of the short circuit. Tin whiskers have already been responsible for at least one failure at a nuclear power plant. Other documented failures include satellites in orbit, aircraft in flight, and implanted medical pacemakers. It should be noted that these failures pre-date RoHS and do not involve consumer electronics, and therefore would be exempt. To help mitigate potential problems, lead-free manufacturers are using a variety of approaches such as tin-zinc formulations that produce non-conducting whiskers. Fortunately, experience thus far suggests deployed instances of RoHS products are not failing due to whisker growth. Dr. Ronald Lasky of Dartmouth College
reports: “RoHS has been in force for more than 15 months now, and ~$400B RoHS-compliant products have been produced. With all of these products in the field, no significant numbers of tin whisker-related failures have been reported.” Whisker growth can occur slowly over time, is unpredictable, and not fully understood, so time may be the only true test of these efforts.
Reliability decay of low-lead materials may be economically desirable for some consumer product companies because it provides a mechanism to enforce planned obsolescence and replacement. Ironically, this is the opposite of the claimed intent of RoHS legislation.[citation needed] Some countries have exempted medical and telecommunication infrastructure products from the legislation. However, this may be a moot point, as electronic component manufacturers convert their production lines to producing only lead-free parts, conventional parts with eutectic tin-lead solder will simply not be available, even for military, aerospace and industrial users. To the extent that only solder is involved, this is at least partially mitigated by many lead-free components’ compatibility with lead-containing solder processes. Leadframe based components, such as QFPs, SOICs, and SOPs with gull wing leads, are generally compatible since the finish on the part leads contributes a small amount of material to the finished joint. However, components such as BGAs which come with lead-free solder balls and leadless parts are often not compatible with lead-containing processes.
Economic effect There are no de minimus exemptions, e.g., for micro-businesses, meaning that some small businesses have closed down, citing the cost of compliance. This economic effect was anticipated and at least some attempts at mitigating the effect were made. Another form of economic effect is the cost of product failures attributed to RoHS compliance. For example, tin whiskers were responsible for a 5% failure rate in certain components of Swiss Swatch watches in 2006, reportedly triggering a $1 Billion recall. Swatch responded to this by applying for exemptions to RoHS compliance for two components.
One of these exemptions was effectively approved, with the other still pending after an initial denial. For the denied part Swatch has stated to be using a replacement solder that is almost pure lead, and its application was for permission to switch to a solder with a lower lead content.
Tin phase transformation In an article published in Advanced Packaging, November/December 2006, Glenn A. Rinne of Unitive Electronics, Inc. (an Amkor Company) describes the allotropic phase transformation of tin, also known as tin pest, which begins at temperatures below 13°C (about 55°F). Tin pest causes solder joints affected by it to crumble. The effect is difficult to predict and control, because the transformation is slow.
Interestingly, the effect was already known more than 100 years ago, as it has at various times been cited as a factor in the failure of Napoleon’s Russian campaign, and Robert Scott’s South Pole expedition.
About the author:
A tech-savy person, exploited nature at first But now, He had made it a point to save mother earth. Sharing his green mind worldwide is his pleasure.
