In Compliance: The Compliance Information Resource for Electrical Engineers logo
Toward Standardization of
Low Impedance Contact CDM
PLUS
Static Control Flooring in High Reliability Environments

System-Level Grounding

Caster Contact:
The Achilles Heel of ESD Floors

PLUS
Static Control Flooring in High Reliability Environments

System-Level Grounding

Caster Contact:
The Achilles Heel of ESD Floors

September 2021
September 2021
Volume 13 l Number 9
Contents
By Nathan Jack, Brett Carn, and Josh Morris
The 16.6 ohm implementation of contact CDM (LICCDM) recently published in ANSI-ESD Standard Practice 5.3.3 is shown to produce waveforms of similar shape, Ifail, and Ipeak vs. Ceff dependency as JS-002. The non-monotonicity of JS-002 at low voltages is overcome using LICCDM. A path to joint standardization with air discharge testing is proposed.
By Tom Ricciardelli
High reliability organizations (HROs) typically implement stringent static control programs to mitigate the risks of catastrophic and/or life-threatening failures. This article describes some of the considerations to consider for static control flooring in these more demanding environments.
By Vladimir Kraz
Grounding is often viewed from separate points of view – safety, ESD, or EMI.  This article combines all these aspects together so that practitioners can address grounding at the factories and in the laboratories in a comprehensive way.
By David Long
A fully functional ESD floor prevents static generation and provides an effective path to ground for personnel and equipment. Many conductive and dissipative floors meet STM 7.1 resistance parameters in ANSI/ESD S20.20 but fail to provide adequate electrical contact for grounding equipment with conductive casters and drag chains.
someone holding a phone with electricity coming out
person walking in a protection suit in a lab
ESD and EMI
the legs and wheels of a rolling chair
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A Preview of the Symposium taking place in Tucson, Arizona September 26 – 30, 2021
Tucson, Arizona
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In Compliance Magazine
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Daryl Gerke
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columns contributors
EMC Concepts Explained
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Hot Topics in ESD
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compliance news
FCC to Require Electronic Filing of International Applications, Reports
The U.S. Federal Communications Commission (FCC) has extended its requirements for the electronic filing of applications and reports submitted to the agency for review.

The Commission will require that all reports and applications administered by its International Bureau be filed electronically through its International Bureau Filing System (IBFS). The expanded requirements will apply to Section 325(c)…

Report Addresses Fires Attributable to Lithium Batteries
As part of an effort to reduce the risk of fires caused by lithium batteries in waste electrical and electronic equipment (WEEE), a consortium of industry groups has just issued a report that compiles a number of “good practices” applicable to all phases of the product development process.

The report, “Recommendations for Tackling Fires Caused by Lithium Batteries in WEEE,” compiles the findings…

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DILBERT © 2021 Scott Adams. Used By permission of ANDREWS MCMEEL SYNDICATION. All rights reserved.
Feature Article
Toward Standardization of Low Impedance Contact CDM
By Nathan Jack, Brett Carn, and Josh Morris
man with cell phone in hands with electricity coming out of it
Editor’s Note:  The paper on which this article is based was originally presented at the 41 st Annual EOS/ESD Symposium, where it was awarded the Symposium Outstanding Paper in 2020. It is reprinted here with the gracious permission of the EOS/ESD Association, Inc.
Introduction
The field-induced Charged Device Model (CDM) test method standardized in ANSI/ESDA/JEDEC JS-002 [1] is widely used for CDM qualification of integrated circuits. Because it relies on an air spark to initiate the stress, the pulse amplitude varies from zap to zap [2]. This discharge variation is increasingly significant as pre-charge voltage Vpre decreases [3].

Relay-based alternatives have been proposed to eliminate the variable air spark [2], [4]. Such “contact CDM” (CCDM) systems rely on transmission line pulsing and utilize 50 Ω coaxial cables and relays. It has been shown that 50 Ω systems generate pulses much wider than those of JS-002, but a better match can be obtained using lower system impedances. In [3], CCDM systems of 50 Ω, 25 Ω, and 11 Ω impedances were demonstrated. It was theorized that a 16.6 Ω CCDM system would provide the closest match to JS-002 in terms of waveform shape and the failure current (Ifail) thresholds generated.

Is your ESD floor
caster compliant?
ESD floors ground more than people. Your floor must also keep carts, chairs and shelves at the same potential.

ESD chip floors, while they may pass a simple test like ANSI S7.1, solve only 50% of the problem. With a surface area the size of a dime, wheels and casters can slip into gaps between the chips.

StaticWorx ESD tiles provide 100% protection and are always caster-compliant.

staticworx logo and website
Dimes on marble counter with heads facing up
Is your ESD floor caster compliant?
ESD floors ground more than people. Your floor must also keep carts, chairs and shelves at the same potential.

ESD chip floors, while they may pass a simple test like ANSI S7.1, solve only 50% of the problem. With a surface area the size of a dime, wheels and casters can slip into gaps between the chips.

StaticWorx ESD tiles provide 100% protection and are always caster-compliant.

staticworx logo
617-923-2000
EOS/ESD Symposium Preview
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Tucson, Arizona
September 26 - 30, 2021
Wolfgang Stadler headshot
Wolfgang Stadler
General Chair
Dear colleagues, friends, and ESD enthusiasts,
On behalf of EOS/ESD Association, Inc. and the 2021 Symposium Steering Committee, it is my honor to welcome you to the proceedings of the 43rd Annual EOS/ESD Symposium and Exhibits at The Westin La Paloma Resort & Spa in Tucson, Arizona. The EOS/ESD Symposium represents the world’s leading forum on Electrostatic Discharge and Overstress. Although COVID-19 is still impacting our business and operations significantly, the Steering Committee and the Technical Program Committee, with all our great volunteers, spared no effort to ensure that the 43rd Symposium is a great experience for all attendees, on-site or virtually online.

In the 43rd EOS/ESD Symposium, the Steering Committee and the Symposium Strategy Team have structured the program in five focus areas, each with a program of 1-1.5 days. The focus areas are Advanced Technologies and Device Testing, Automotive, Communications, Mixed Voltage Applications, and, as in the last years, EMC. Each focus area comprises one or several sessions with technical papers, invited talks, tutorials, seminars, and workshops. For the first time, the Symposium started on Monday and was, therefore, one day longer than in the past, allowing more time for program and discussion. In parallel, for the fifth time, the “Manufacturing Track” offers full 3.5 days of technical sessions, hands-on sessions, workshops, discussion groups, and technology showcases in the field of EOS/ESD in manufacturing – control materials, technologies, and techniques.

Special Industry Update
clipart of a lightning bolt
Industry Council Survey on Latch-up: A Brief Status Update
By Theo Smedes (NXP Semiconductors) for the Industry Council on ESD Target Levels
In July 2020, the Industry Council on ESD Target levels, in collaboration with the JEDEC JESD78 working group, launched a survey on Latch-up testing. An earlier article1 in this magazine described the reasons for launching the survey and invited representatives from the industry to participate in order to collect data and opinions. The survey is now closed, but a full pdf version of the survey2 is still available online. This article will give a short update on the results of the response analysis that is ongoing.

The Industry Council received 70 individual responses, from at least 35 companies from more than 16 countries. Multiple responses per company were encouraged because of the wide diversity of products, customers, and requirements. Although the survey was oriented at Revision E of the JESD78 standard, it is, of course, relevant to know which standards are actually used. The responses show that although other test standards and older JESD78 revisions are also used, the most prevalent standard in use is JESD78E. This gives good confidence in the relevance of the responses with respect to the survey’s goals.

Feature Article
Static Control Flooring in High Reliability Environments
Special Considerations for Static Control Flooring for Added Risk Reduction
By Tom Ricciardelli
worker wearing static suit walking over floor signage reading "ESD Protected Area"
S

tatic control flooring is widely used throughout the electronics industry to provide a means to ground personnel and mobile equipment to control static charge generation and build-up. While I’d argue that it is always important to control static in an electronics manufacturing environment, there are some organizations where the risk of a device failure could have more serious consequences. This raises the bar in terms of managing the risk of failure and there are some things you should keep in mind when choosing static protective flooring to help with that.

What is High Reliability?
A group of researchers at the University of California, Berkeley, in their research to understand causes of major failures, identified certain organizations that were better at handling and avoiding these failures. 1,2  In their work, they defined a high reliability organization (HRO) as “an organization that has succeeded in avoiding catastrophes in an environment where normal accidents can be expected due to risk factors and complexity.” They further defined the five principles that HROs have in common:
Feature Article
System-Level Grounding
Is Your System Well Grounded? Consider These Points in Effective Grounding
By Vladimir Kraz
Illustrations
G

rounding is the most fundamental property of all types of electrical equipment. There are plenty of quality articles on specific subjects in In Compliance Magazine and in other publications, largely on grounding on a printed circuit board (PCB) level. This article focuses on a path less traveled, grounding on a system level, that is grounding of the equipment in actual use at the factories.

There are several key aspects of grounding, including safety, ESD, EMI, and signal integrity. While this and other magazines have published detailed articles on one or more of these subjects, this article combines them all to assist equipment users and tool makers in understanding what is important and how to achieve optimal ground performance. This article does not cover PCB grounding (there are plenty of excellent articles on this subject) and portable tools with double insulation that do not have grounding.

Feature Article
Caster Contact:
The Achilles Heel of ESD Floors
Standard ESD Resistance Tests Do Not Fully Evaluate a Floor’s Suitability for Grounding Carts, Chairs, and Mobile Workstations
By David Long
chair with caster wheels
W

hat’s the purpose of installing an ESD floor? The most common answer to this question is “we need ESD flooring to prevent static charges on mobile personnel when they handle static sensitive parts and systems.” In other words, we need the effectiveness of a wrist strap, but we don’t want to deal with the restrictions of wires and cords.

While this answer highlights a key attribute of a properly functioning ESD floor, it sets the bar very low. It also short sells the many advantages an ESD floor actually offers. Like every other static mitigation component, ESD flooring is only one piece of a larger comprehensive system that keeps all parts, machines, tools, packaging, work surfaces, and personnel at the same potential.

When floors are evaluated, specifiers focus on two main performance parameters: 1) the flooring system’s electrical resistance; and 2) how much charge a person can develop when walking on the floor wearing specific footwear. But what about the parts themselves? How do we protect them? When we move parts from one operation to another, we don’t cradle them in the palm of our hands. We move parts and systems in zip lock bags, on wheeled carts with trays, and possibly with automatically guided vehicles. In agile manufacturing operations, the ESD floor might even be used as the primary ground for workbenches on wheels.

Upcoming Events
September 14-16
The Battery Show

September 20-24
IEEE International Symposium on Product Compliance Engineering (ISPCE)

September 26- September 30
43rd Annual EOS/ESD Symposium and Exhibits

September 27-30
2021 Asia-Pacific International Symposium on Electromagnetic Compatibility (APEMC)

September 28
IEEE EMC Chicago Mini Symposium

September 30
EMC Fest 2021

October 7
EMC Mini

October 13
5G Antenna Systems

October 18-21
MIL-STD 810 Testing

October 24-29
AMTA 2021

Due to COVID-19 concerns, events may be postponed. Please check the event website for current information.
Design for EMC
Live virtual Training Course
November 9 – 11, 2021
Learn Practical Tools, Tips, and Techniques for Bulletproof Designs
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This expert-led, live, multi-day virtual training focuses on common interference and signal problems faced by the designers of today’s high speed digital and mixed digital/analog circuits and systems and will teach participants how to identify, prevent, and fix common EMC design problems.
  • Learn to address Key EMI threats: Emissions, ESD, RFI, Power Disturbances & More
  • Focus on what is inside the box: Components, Printed Circuit Boards, Power Electronics, Grounding, and Shielding.
  • Includes over 35 Practical Design EMC Fixes!
  • Participate in interactive discussions and learn from realistic scenarios
  • Increase your skillset from the comfort of your home or office
  • Become more confident and efficient in your product design
  • Learn to address Key EMI threats: Emissions, ESD, RFI, Power Disturbances & More
  • Focus on what is inside the box: Components, Printed Circuit Boards, Power Electronics, Grounding, and Shielding.
  • Includes over 35 Practical Design EMC Fixes!
  • Participate in interactive discussions and learn from realistic scenarios
  • Increase your skillset from the comfort of your home or office
  • Become more confident and efficient in your product design
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TAUGHT BY A RECOGNIZED AUTHORITY AND SPECIALIST IN THE FIELD.
Learn tools, tips and techniques from full time practitioner Daryl Gerke. PE, whose only business is solving and preventing EMC and related signal integrity problems. He has prevented or solved hundreds of EMI problems for clients in a wide range of industries. He has co-authored three books on EMC and over 200 technical articles.
Presented by EMI Guru
in partnership with
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Thanks for reading our September 2021 issue!