EECS
2015+1-1,2,3+all.pdf

# 3 can put electric charges only on insulators 4 can

• Notes
• 146

This preview shows pages 144–146. Sign up to view the full content.

3. Can put electric charges only on insulators. 4. Can cause sparks. The false statements are: A. Only 1 B. 1 and 2 C. 1. 2, and 3 D. 3 and 4 E. All on the list. Answer to this problem is at the end of the Unit. Book Page 144

This preview has intentionally blurred sections. Sign up to view the full version.

EE for 21 st century 1-3 Prevent electrostatic discharge 1-3-1 Hazards of ESD for EE © 2015 Alexander Ganago Page 22 of 23 Last printed 2015-07-24 6:00 PM File: 2015 1-3-1 ESD.docx K EY CONCEPTS , OR S UMMARY OF NEW LEARNING v The elementary positive charge (of a proton) equals 1.602 · 10 -19 C. The elementary negative charge (of an electron) has the exactly same magnitude. v Triboelectric effect or charging occurs when two materials are brought in close contact and then separated. v Triboelectric series is a list of materials sorted according to the sign and magnitude of static electric charges that they accumulate due to rubbing. v The universal principle of the conservation of electric charges maintains that the net charge of a closed system remains unchanged. It means that electric charges can be separated and/or recombined but never created or destroyed. v Conductors and insulators, as well as water, air, and dust particles in the air can bear electrostatic charges. v By simple everyday actions such as walking across carpet, one can easily accumulate static electric charges that generate voltages up 35,000 V. v The voltages generated by static electric charges get lower if the air is humid. v Electrostatic discharge (ESD) is the transfer of charge between bodies at different electric potentials. v Voltages as low as 100 V can cause ESD damage to electronic devices. v ESD damage to electronic devices may be catastrophic or latent. v An electronic device damaged by ESD may cause failure of the product where it is installed. v Two main strategies for ESD prevention are: I. Prevent accumulation of static electric charges at the workplace. II. Remove from the workplace the electric charges, which are already accumulated there. v Conductive materials have low electrical resistance: their electrons can freely flow across the volume or surface of such materials. v Ground is an electric connection to Mother Earth, which has zero electric potential. v Static electric charges can be removed from conductors by grounding. v Static electric charges can be removed from the human body by grounding via wrist straps, heel and toe attachments to shoes, etc. v Insulative materials have high electric resistances because electrons cannot freely move across their volume and surface. v Grounding does not remove static electric charges from insulators. v Air ionizers and humidifiers help to remove static electric charges from insulators. v Electric resistances of static dissipative materials are between those of insulators and conductors. v Static dissipative materials are specially designed for the removal of static electric charges and are manufactured in many forms, including wrist straps, desk mats, and floor tiles.
This is the end of the preview. Sign up to access the rest of the document.
• Fall '07
• Ganago
• Electric charge, Alexander Ganago

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern