Standards organizations come in a variety of sizes. No matter the size, these groups share an analogous trait: they are the cohesive force steering the membership through a mine field of differing opinions.
The ESD Association is just such an organization, supplying manufacturers and users with procedural ground rules and a platform for ideas. It has progressed from a small group to a nearly 2,000-member organization that is respected and consulted for ESD-control and testing guidance by the electronics industry.
The association continues to gain stature on its road to world-class recognition. It has forged relationships with national and worldwide groups including the American National Standards Institute (ANSI) and the International Electrotechnical Commission (IEC).
ANSI is an internationally recognized private organization that coordinates the U.S. voluntary consensus standards system. The IEC sets standards for electronic components which are adopted by the safety standards agencies of many countries.
In 1992, the ESD Association became an ANSI-accredited Standards Development Organization. The connection means the association follows ANSI procedures, reviews and approvals, and can put the ANSI designation on documents that meet its requirements.
The involvement with ANSI and its established authority parlays into greater acceptance of the ESD Association. With the quality procedures required by ANSI,
all standards must go through an industry-wide review process. The result is a better document with wider industry usage.
ANSI accreditation makes the ESD Association’s standards more accessible to the industry. The review process now reaches a larger segment of the industry than the association reached previously. The ANSI accredited standards also receive wider exposure through ANSI marketing efforts.
International exposure is another facet of the relationship with ANSI. Through the U.S. National Committee, ANSI is the representative to the IEC which makes the ESD Association the official U.S. representative to the IEC for electrostatics. This alliance allows the association to have formal input into the development of international standards via the U.S. representative, Dave Swenson, Technical Committee chairman, and the Canadian representative, Ron Gibson, President of the Board of Directors.
Since 1992, the ESD Association, under the auspices of ANSI, has published more than a dozen documents, including standards, draft standards and advisories. Nine standards have been approved with an ANSI designation.
Recently, the ESD Association accepted the task of developing MIL-STD-1686 Electrostatic Discharge Control Program for Protection of Electrical and Electronic Parts, Assemblies and Equipment as a commercial document. The military selected
the association partially because of its ANSI accreditation.
The ESD Association also has established a link to the National Association of Radio and Telecommunications Engineers (NARTE). It is a nonprofit corporation that certifies engineers and technicians in the telecommunications, EMI and ESD fields. NARTE provides a focal point and venue for addressing issues affecting these professionals and represents them at the federal and state levels.
The NARTE connection supplies professional credentials of achievement to a recognized industry standard and assures that members meet a measurable level of expertise. To attain the NARTE ESD engineer grade, you must pass a test, supply letters of recommendation and have a minimum of nine years experience and schooling in ESD. The first NARTE exam for ESD engineers and technicians is slated to be ready this month.
The Route to a Full Standard
Before a document is elevated to the level of a standard, it usually goes through a several-step process. The first step is a work in process. This designation applies to an unapproved document, one that is in discussion by a working group. Here, the groundwork is laid and the potential standard is sculpted into shape.
Initial testing works out the kinks in new procedures to derive consistent test results. It then proceeds to a draft standard.
Draft Standard
The draft standard is developed using material prepared by the working group and received by the association’s Standards Committee and Board of Directors. Then it is distributed for comment and review by the industry. The draft standard may be revised before it becomes a full standard. The current draft standards are:
· ESD DS1.1-1996 Evaluation, Acceptance and Functional Testing of Wrist Straps. This is a successor to the 1987 EOS/ESD S1.0. It establishes test methods for evaluating the electrical and mechanical characteristics of wrist straps. It includes improved test methods and performance limits.
· ESD DS2.1-1995 Resistance Test Method for Electrostatic Discharge Protective Garments. It provides test methods for measuring the electrical resistance of garments used to control electrostatic discharge, and covers procedures for measuring sleeve-to-sleeve and point-to-point resistance.
· ESD DS4.1-1995 (Revised) Worksurfaces—Resistive Characterization. It updates ANSI EOS/ESD S4.1-1990.
· ESD DS4.2-1996 Worksurfaces—Charge Dissipation Characteristics. It provides a test method that helps determine the capability of ESD protective worksurfaces to dissipate a charge from a test object placed on the surface.
· ESD DS5.2-1996 Electrostatic Discharge Sensitivity Testing—Machine Model. It defines a test method that simulates an ESD event occurring from a low-resistance source. The component damage caused by the machine model is often similar to that caused by the human body model, but occurs at a significantly lower voltage. This document contains technical changes to the ANSI ESD S5.2-1994 standard that modifies the test procedures and makes them more user friendly.
· ESD DS5.3-1996 Electrostatic Discharge Sensitivity Testing—Charged Device Model. It establishes a test method for evaluating the ESD sensitivity of components to a defined charged device model using the non-socketed test method. The draft standard also provides a system of classifying the sensitivity of components.
· ESD DS11.2-1996 Volume Resistance Measurement of Static Dissipative Planar Materials. It offers test methods for measuring the volume resistance of static-dissipative planar materials.
· ESD DS12.1-1995 Seating—Resistive Characterization. It supplies test methods for measuring the electrical resistance of seating used to control ESD. The test methods are used for qualifying as well as for evaluating and monitoring seating after installation. It covers all types of seating, including chairs and stools.
Full Standard
A full standard has completed the industry comment and review process. It is also approved by the Standards Committee and Board of Directors of the ESD Association. Current full standards are:
· EOS/ESD S1.0-1987 Wrist Straps. It establishes requirements for personnel grounding wrist straps. The standard covers mechanical and electrical requirements and supplies specifications for qualification and periodic monitoring of wrist straps.
· ANSI EOS/ESD S3.1-1991 Ionization. It provides test methods and procedures for evaluating and selecting air ionization equipment and systems. The standard institutes measurement techniques to determine ion balance and charge-neutralization time for ionizers.
· ANSI EOS/ESD S4.1-1990 Worksurfaces—Resistive Characterization. It establishes test methods for measuring the electrical resistance of worksurface materials used at workstations for protecting ESD-susceptible items. The standard includes methods for evaluating and selecting materials, and testing new worksurface installations and previously installed worksurfaces.
· ANSI EOS/ESD S5.1-1993 Revised, Electrostatic Discharge Sensitivity Testing—Human Body Model. It assigns a procedure for evaluating the ESD sensitivity of components to a defined human body model. The standard covers test procedures and classifies component sensitivity.
· ANSI ESD S5.2-1994 Electrostatic Discharge Sensitivity Testing—Machine Model. It establishes a test procedure for evaluating the ESD sensitivity of components to a defined machine model. The standard also provides a system of classifying the sensitivity of these components.
· ANSI EOS/ESD S6.1-1991 Grounding—Recommended Practice. It recommends the parameters, procedures and types of materials needed to establish an ESD grounding system for the protection of electronic hardware from ESD damage. The standard is used on personnel grounding devices, worksurfaces, chairs, carts, floors and related equipment.
· ANSI ESD S7.1-1994 Floor Materials—Resistive Characterization of Materials. It covers measurement of the electrical resistance of various floor materials such as floor coverings, mats and floor finishes. The standard provides test methods for qualifying floor materials before installation or application and for evaluating and monitoring materials after installation or application.
· ANSI ESD S8.1-1993 ESD Awareness Symbols. It establishes three types of ESD awareness symbols. The first symbol is used on a device or assembly to indicate that it is susceptible to electrostatic charge. The second is used on items and materials intended to provide electrostatic protection. The third indicates the common point ground.
· ESD S9.1-1995 Resistive Characterization of Footwear. It provides a test method for measuring the electrical resistance of shoes used for ESD control in the electronics environment.
· ANSI ESD S11.11-1993 Surface Resistance Measurement of Static Dissipative Planar Materials. It defines a direct current test method for measuring electrical resistance. The standard replaces ASTM D257-78 for testing static dissipative planar materials used in packaging of ESD-sensitive devices and components.
· ANSI ESD S11.31-1994 Evaluating the Performance of Electrostatic Discharge Shielding Bags. It provides a method for determining and testing the shielding capabilities of electrostatic shielding bags.
Further Assistance
The ESD Association also offers information in the form of advisory documents. They provide general information to better understand the association’s standards. The documents are:
· ESD ADV1.0-1994 Glossary of Terms. It defines and explains various terms used in association standards and documents. The document also covers terms commonly used in the ESD industry.
· ESD ADV2.0-1994 ESD Handbook. It is a complete guide to static control in the work place. Nineteen chapters cover ESD basics, control procedures, auditing, symbols, device testing and standards.
· ESD ADV3.2-1995 Selection and Acceptance of Air Ionizers. It supplies guidelines for creating a performance specification for selecting air ionization systems. The document reviews four types of air ionizers and discusses applications, test method references and general design, performance and safety requirements.
· ESD ADV11.2-1995 Triboelectric Charge Accumulation Testing. It provides information to help explain the phenomenon of triboelectric charging. The document covers the theory and effects of tribocharging. It reviews procedures and problems associated with various test methods used to evaluate triboelectrification characteristics. The test methods indicate only gross levels of charge and polarity.
· ESD ADV53.1-1995 ESD Protective Workstations. It establishes the minimum requirements for a basic ESD protective workstation used in ESD-sensitive areas. The document provides a test method for evaluating and monitoring workstations. It defines workstations as having a support structure, a static-dissipative worksurface and a
way to ground personnel and attach shelving or drawers.
Acknowledgment
Material for the article was supplied by Michael Brandt, President of Marketing Resources. He is a long-time member of the ESD Association, serves on the Standards Committee, chairs the Glossary/Handbook Work Group, and is a member of the Flooring Standards Work Group.
Copyright 1996 Nelson Publishing Inc.
December 1996