Environment Friendly Engineering: An Ethical Responsibility of an Engineer

ForEEL 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 Profession

Environment

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

Performance

Product Design

Production Cost

Environment

Hazardous materials

Design for Environment DfE (contd.)

Replacing the hazardous materials

Design Adjustment

Selection of proper replacement

Toxicology

Manufacturing Process

Reliability

Material properties

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

Electric power Generation

Design energy efficient electronic products

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