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Environment Friendly Engineering: An Ethical
Responsibility of an Engineer
For
EEL 5344: Digital CMOS VLSI Design
Engineering Ethics
• Engineering ethics
• application of moral principles and professional standards to
situations encountered by professionals in the practice of engineering.
Engineers’ Responsibilities
Public
Client
Employer
Environment
Profession
Engineering Ethics (contd.)
• Code
of Ethics
• Institute
of Electrical and Electronics Engineers (IEEE)
We, the members of the IEEE, in recognition of the importance of our technologies in affecting the quality of life
throughout the world, and in accepting a personal obligation to our profession, its members and the communities
we serve, do hereby commit ourselves to the highest ethical and professional conduct and agree:
to accept responsibility in making decisions consistent with the safety, health and welfare of the public, and to
disclose promptly factors that might endanger the public or the environment;
to avoid real or perceived conflicts of interest whenever possible, and to disclose them to affected parties when
they do exist;
to be honest and realistic in stating claims or estimates based on available data;
to reject bribery in all its forms;
to improve the understanding of technology, its appropriate application, and potential consequences;
to maintain and improve our technical competence and to undertake technological tasks for others only if
qualified by training or experience, or after full disclosure of pertinent limitations;
to seek, accept, and offer honest criticism of technical work, to acknowledge and correct errors, and to credit
properly the contributions of others;
to treat fairly all persons regardless of such factors as race, religion, gender, disability, age, or national origin;
to avoid injuring others, their property, reputation, or employment by false or malicious action;
to assist colleagues and co-workers in their professional development and to support them in following this code
of ethics.
Environmental Hazards due to Electronics
Electronics
E-Waste
E-Waste
• Formed by discarded electronic equipments like
monitors, CPUs, cell phones.
• Contains the following toxic heavy metals and
chemicals,
• Lead
• Cadmium
• Mercury
• Beryllium
• Hexavalent Chromium
• Polyvinyl Chloride (PVC) plastics
• Brominated flame retardants
E-Waste (contd.)
• Lead
Usage: soldering of electronic components like PCBs, capacitors, interconnects.
Hazard: damages the nervous system and kidneys, impairs brain development in
children.
• Cadmium
Usage: as a semiconductor, batteries, stabilizers, switches.
Hazard: damage of kidneys and bones, heart disease, affects respiratory system.
• Mercury
Usage: relays, switches, lamps, thermostats, batteries.
Hazard: affects central nervous system, hinders brain development,
cardiovascular diseases.
E-Waste (contd.)
• Beryllium
Usage: motherboards for external connections.
Hazard: chronic beryllium disease (CBD), affects lungs.
• Hexavalent Chromium
Usage: to prevent corrosion of steel and metal surfaces.
Hazard: carcinogenic, causes cancer
• Polyvinyl Chloride (PVC) plastics
Usage: insulation of wires and cables.
Hazard: affects respiratory system.
• Brominated flame retardants
Usage: to prevent combustion and spreading of flame.
Hazard: affects neurobehavioral development through mother’s milk.
Design for Environment DfE
Production
Cost
Product Design
Performance
Environment
Hazardous
materials
Design for Environment DfE (contd.)
Material properties
Replacing the hazardous
materials
Toxicology
Selection of proper
replacement
Manufacturing Process
Reliability
Design Adjustment
Economics &
Availability
Lead-free Electronics
• Lead (Pb) is present as Tin Lead (SnPb) alloy for
soldering purposes at printed circuit boards (PCBs)
• Possible replacement – Tin Silver Copper (SAC) alloy
• Melting temperature
• SnPb – 187 oC
• SAC – 217-218 oC
• High process temperature affects PCB design.
Lead-free Electronics (contd.)
• PCB design factors for Lead-free assembly
• change in the physical footprint.
• change in surface mounted devices (SMDs) that
do not comply with the high process temperature
requirement.
• change in placement and routing.
• change in differential impedance calculation.
Legislations for the Environment
• RoHS directive along with WEEE directive
• RoHS stands for ”the restriction of the use of certain hazardous substances in
electrical and electronic equipment” or simply Restriction of Hazardous
Substances.
• WEEE stands for Waste Electrical and Electronic Equipment
• created by the European Union.
• took effect on July 1, 2006.
• restricts 6 toxic materials used in electronics
• lead
• cadmium
• mercury
• hexavalent chromium
• polybrominated biphenyl (PBB) flame retardant
• polybrominated diphenyl ether (PBDE) flame retardant
Environmental Hazards due to Electronics
Electronics
E-Waste
Global Warming
Global Warming due to Electronics
Global warming
Emission of
greenhouse
gases
Fossil fuel
combustion
Design energy efficient
electronic products
Electric power
Generation
Energy Efficient Electronic Devices
What are the factors of energy efficient electronic devices
power consumption is less
power dissipation is less
does not get heated up
less damage to electronic parts
What are the advantages of energy efficient electronic devices
higher performance efficiency
lower maintenance cost
The main idea is to reduce power consumption and dissipation
Low Power Design
Low Power Design
• Device level low power design
• Electronic Devices use CMOS technology
• Power dissipation in CMOS technology
• Static power dissipation
• when the device is OFF
• leakage current
• Dynamic power dissipation
• when the device is ON
• switching
• Short-circuit power dissipation
• when Vdd and Gnd are shorted
Low Power Design (contd.)
• Static power dissipation
• Leakage current
• subthreshold leakage
• gate leakage
• gate induced drain leakage
• reverse bias leakage
• punchthrough
• Design parameters
• threshold voltage
• channel length
• gate oxide thickness
• temperature
Low Power Design (contd.)
• Dynamic power dissipation
• Design parameters
• switching activity (a)
• supply voltage (Vdd)
• clock frequency (Fclk)
• load capacitance (CL)
Data Centers
• Data center
• facility for computing systems
• servers
• communication systems
• storage systems
• Functions
• to store data
• to perform efficient computation
• Usage
• World Wide Web providers
• Software industries
• Electronic design industries
Data Centers (contd.)
• Microsoft’s data center in Quincy, Washington
• Size
• 450,000 square feet.
• computers are racked in five 12,000 foot
clusters.
• 1.5 tons of batteries.
• 600 miles of electrical wire.
• Power consumption
• consumes 48 megawatts of power.
• enough to power approximately 40,000
homes.
Data Centers (contd.)
• Energy efficient data center design
• reduction of hardware.
• designing compact multifunctional
circuits to minimize the size of
servers.
• minimize the area.
• efficient arrangement of devices.
• streamlining power supplies.
• streamlining communication cables.
• designing efficient cooling systems.
Data Centers (contd.)
• Blade servers
• Design
• designed by having only the essential parts
• memory
• processor
• storage just enough to perform
efficient computing
• discards other parts like power
supply, I/O interface, hard drive etc.
• Makers
• Sun, IBM, Intel
• Advantages
• compact, consumes less power, simplifies
expansion, low maintenance
Data Centers (contd.)
• Green Grid
• global consortium dedicated to advancing energy
efficiency in data centers and business computing
ecosystems.
• Members
• AMD, APC, Dell, HP, IBM, Intel, Microsoft,
Rackable Systems, SprayCool, Sun Microsystems
and VMware.
• Actions
• defining meaningful, user-centric models and metrics
• developing standards, measurement methods,
processes and new technologies to improve data center
performance against the defined metrics
• promoting the adoption of energy efficient standards,
processes, measurements and technologies.
Summary
• Important ethical responsibility of an engineer
 towards environment
• E-Waste
• Lead-free electronics
• RoHS and WEEE directives
• Global Warming due to energy consumption
• Low power electronic design
• Data centers