Conformity Magazine

See this article in our Digital Edition
Download a pdf of this article (right click to save the pdf)

With the economy steadily improving, many companies are looking for ways to increase profits and overall performance within their particular industry. The electronics industry is no exception. Many electronics companies are working towards improved quality and reliability at the same rate as improving the performance of the products they manufacture. In the latter part of 2005, the ESD Association released an “ESD Technology Road Map” in an effort to create awareness within the global electronics industry of some remarkable changes that were right around the corner.

The “Road Map” pointed out, in dramatic fashion, that numerous mainstream electronic parts and components would reach assembly factories without the same level of ESD protection installed just a few years ago. This prediction has indeed come true. The manufacturing industry may have become a bit complacent in the past few years since many design schemes offered very good levels of ESD protection. However, the ever increasing demands for enhanced performance, speed, storage capacity, and bandwidth, along with a reduction in physical size, has led to the necessary removal of on-chip protection. Nowhere is this more evident than in the world of wireless communication devices and other portable electronic equipment. The features crammed into a pocket-sized cell phone are truly amazing and many more are on the way. As consumers demand and are granted more features, manufacturers must adapt to handling increased ESD susceptibility in their parts.

The ESD Association Standards Committee is “charged” with keeping pace with the industry demands for increased performance. The existing Standards, Standard Test Methods, Standard Practices and Technical Reports assist in the design and monitoring of the Electrostatic Protected Area (EPA), and also assist in the testing of ESD sensitive electronic components. Many of the existing documents relate to controlling electrostatic charge on personnel and stationary work areas. However, with the ever increasing shift to automated handling, the need to evaluate and monitor what is going on inside of process equipment is growing daily. A shift is being made from Human Body Model device susceptibility as the major concern, to Charge Device Model considerations in the typical factory.

There is absolutely no question that the existing ESD Association Standards such as ANSI/ESD S20.20 (Program Development) and ANSI/ESD S541 (Packaging for Shipment) are important to industry. These documents are downloaded from www.esda.org in excess of 2,500 times per month on average. The new ESD Technology Road Map had over 6,000 downloads during 2006. The industry is paying attention. The factory Certification Registrars report strong interest in Certification to S20.20, and the world of consultants in this area report that inquiries for assistance remain at an unprecedented level. Individual education also seems of interest once again as thirteen professionals have obtained Certified ESD Program Manager status and many more are attempting to qualify as Certified ESD Control Program Managers.

A recently introduced educational opportunity is the ESD Device Design Professional Certification program. Similar to the ESD Program Manager Certification in concept, candidates take a required number of tutorials related to electronic device and testing technologies, and successfully complete an exam (scheduled for the fall 2007 EOS/ESD Symposium). For details on this and the Program Manager Certification program, see the ESD Association web site, www.esda.org.

A large percentage of the certification program requirements are based on standards and the other related documents produced by the ESD Association Standards Committee.

Recently released documents include:

TR53-01-06, Compliance Verification of ESD Protective Equipment and Materials;
ANSI/ESD SP5.1.1, Standard Practice for Human Body Model (HBM) and Machine Model (MM) Alternative Test Method: Supply Pin Ganging – Component Level;
ANSI/ESD SP5.1.2, Standard Practice for Human Body Model (HBM) and Machine Model (MM) Alternative Test Method: Split Signal Pin-Component Level.

Standard ANSI/ESD S20.20, Protection of Electrical and Electronic Parts, Assemblies and Equipment (Excluding Electrically Initiated Explosive Devices) was recently revised, and the following documents were recently re-released:

ANSI/ESD S1.1 Wrist Straps;
ANSI/ESD STM3.1 Ionization;
ANSI/ESD S4.1 Worksurface – Resistance Measurements;
ANSI/ESD STM4.2 ESD Protective Worksurfaces – Charge Dissipation; Characteristics ANSI/ESD STM9.1 Footwear – Resistive Characterization;
ANSI/ESD STM12.1 Seating – Resistive Measurement;
ANSI/ESD STM97.1 Floor Materials and Footwear – Resistance Measurement in Combination with a Person;
ANSI/ESD STM97.2 Floor Materials and Footwear – Voltage Measurement in combination with a Person.

Added to this group are:

ANSI/ESD STM11.11, Surface Resistance Measurements of Static Dissipative Planar Materials;
ANSI/ESD STM11.31, Evaluating the Performance of Electrostatic Discharge Shielding Materials – Bags;
ANSI/ESD SP3.3, Periodic Verification of Air Ionizers.

Recent guidance and informational Technical Reports are also available covering the many subjects.

Who Uses Standards and Why?
Who uses ESD standards? The list is quite broad, and includes manufacturers, purchasers, and users of ESD sensitive devices and products, manufacturers and distributors of ESD control products, certification registrars, and third party testers of ESD control products.

Why use ESD standards? The reasons are numerous:

They help assure consistency of the reported susceptibility of ESD sensitive products.
They help assure consistency of ESD control products and services.
They provide a means of objective evaluation and comparison among competitive ESD control products.
They help reduce conflicts between users and suppliers of ESD control products.
They help in developing, implementing, auditing, and certifying ESD control programs.
They help reduce confusion in the marketplace.

In the United States, the use of ESD standards continues to be voluntary. However, their use can be written into contracts or purchasing agreements between buyer and seller. In much of the rest of the world, the use of standards, where they exist, is compulsory.

General Types of Standards
As recently as 1990, there were relatively few reliable ESD standards and many of them were developed for applications other than electronics. In this new century, the landscape has changed significantly with an increasing number of ESD standards developed specifically for the electronics industry.

ESD Association standards can be categorized into four main groups. First, there are those that provide ESD program guidance or requirements, such as ANSI/ESD S20.20-2007 Protection of Electrical and Electronic Parts, Assemblies and Equipment (Excluding Electrically Initiated Explosive Devices); ANSI/ESD S6.1-2005 Grounding—Recommended Practice; and ANSI/ESD S1.1-2006 Wrist Straps. These documents are classified as standards as they all have specific requirements that must be met.

The second type of document is called a standard test method. These documents contain procedures that can be used to evaluate device sensitivity or ESD control products, materials, or processes. The procedures called out in a standard test method should provide reproducible test results when tested by two separate labs. Standard test methods include documents such as ANSI/ESD STM5.1-2001 Device Testing—Human Body Model (HBM) Component Level and ANSI/ESD STM11.13-2004 Two Point Resistance Measurement.

The third type of document is called a standard practice. A standard practice contains content similar to those found in a standard test method with one difference. The procedure is not sufficiently developed to ensure that two labs will get the same result when the procedure is followed. In many cases, a document is released as a Standard Practice so that the industry can start to use it. The working group that issued the standard practice continues their efforts to make the test method repeatable and reproducible with the goal of eventually elevating the document to a standard test method.

Finally, the last category of standards documents includes advisories and technical reports. These types of documents are used to provide educational information to potential users. A good example is the ESD Handbook, TR20.20. This document is a companion publication to ANSI/ESD S20.20 and provides detailed background information on the requirements of the standard as well as a wealth of information on ESD control issues.

Who Are the Primary Standards Developers?
Although there are a number of organizations such as IEST, IDEMA and JEDEC involved in ESD standards development, the ESD Association has become the focal point for the development of ESD standards in recent years. As an ANSI-accredited standards development organization, the Association is charged with the development of ESD standards and test methods. The Association also represents the United States on the International Electrotechnical Commission’s Technical Committee 101-Electrostatics. The ESD Association has published 32 standards documents and 19 technical reports covering material and program requirements, electrostatic device sensitivity, and test methodology for evaluating ESD control materials and products.

Traditionally, the U.S. military spearheaded the development of specific standards and specifications with regard to ESD control in the United States. Today, however, U.S. military agencies are taking a less proactive approach, relying on commercially developed standards rather than developing standards themselves. The international community, led by the International Electrotechnical Commission (IEC), has also taken an active role in standards development. Europe’s CENELEC has issued a European electrostatic standard, EN 61340-5-1 Protection of Electronic Devices from Electrostatic Phenomena—General Requirements that was adopted as a European Norm.

Summary
The ever changing and dynamic electronics world will face additional challenges as discussed in the “ESD Technology Road Map.” The technical and manufacturing communities will need to monitor processes to make sure they are capable of handling parts with greater ESD sensitivity than they have had to deal with in recent years. Keeping up with the changes in the electronics industry is a task that the ESD Association Standards Committee must face on nearly a daily basis - a daunting task for a volunteer organization. n

The ESD Association is the largest industry group dedicated to advancing the theory and the practice of ESD avoidance, with more than 1500 members worldwide. Readers can learn more about the association and its work at
www.esda.org. Special thanks to Carl Newberg for his assistance in preparing this article.

ESD standards are available from the following sources:

ESD Association, 7900 Turin Road, Building 3, Rome, NY 13440. Phone: 315-339-6937; fax: 315-339-6793; email: info@esdsa.org; website: www.esda.org.
International Electrotechnical Commission, 3, rue de Varembe, Case postale 131, 1211 Geneva 20, Switzerland. Fax: 41-22-919-0300; website: www.iec.ch.
Military Standards, Naval Publications and Forms Center, 5801 Tabor Avenue, Philadelphia, PA 19120.

References

“ESD Control: A Profitable Opportunity in Tight Economic Times,” Stephen A. Halperin, Threshold, January/February 2003 (Rome, NY: ESD Association) 8-9.
“ESD Standards: An Annual Progress Report,” Dave Swenson, Conformity, May 2006.

The ESD Association issues four distinct types of standards documents:

Standard (S): A precise statement of a set of requirements to be satisfied by a material, product, system or process that also specifies the procedures for determining whether each of the requirements is satisfied.

Standard test method (STM): A definitive procedure for the identification, measurement, and evaluation of one or more qualities, characteristics, or properties of a material, product, system or process that yields a reproducible test result.

Standard practice (SP): A procedure for performing one or more operations or functions that may or may not yield a test result. Note: if a test result is obtained, it may not be reproducible between labs.

Technical Report (TR): A collection of technical data or test results published as an informational reference on a specific material, product, system, or process.

Table 1: Types of ESD Association Documents

ANSI/ESD S1.1-2006 Wrist Straps
This document establishes test methods for evaluating the electrical and mechanical characteristics of wrist straps. It includes improved test methods and performance limits for evaluation, acceptance, and functional testing of wrist straps.

ANSI/ESD STM2.1-1997 Garments
This standard test method provides test methods for measuring the electrical resistance of garments used to control electrostatic discharge. It covers procedures for measuring sleeve-to sleeve and point-to-point resistance.

ANSI/ESD STM3.1-2006 Ionization
Test methods and procedures for evaluating and selecting air ionization equipment and systems are covered in this standard test method. The document establishes measurement techniques to determine ion balance and charge neutralization time for ionizers.

ANSI/ESD SP3.3-2006 Periodic Verification of Air Ionizers
This standard practice provides test methods and procedures for periodic verification of the performance of air ionization equipment and systems (ionizers).

ANSI/ESD S4.1-2006 Worksurfaces—Resistance Measurements
This standard establishes test methods for measuring the electrical resistance of worksurface materials used at workstations for protection of ESD susceptible items. It includes methods for evaluating and selecting materials.

ANSI/ESD STM4.2-2006 ESD Protective Worksurfaces—Charge Dissipation Characteristics
This standard test method provides a test method to measure the electrostatic charge dissipation characteristics of worksurfaces used for ESD control.

ANSI/ESD STM5.1-2001 Electrostatic Discharge Sensitivity Testing—Human Body Model (HBM) Component Level
This standard test method updates and revises an existing standard. It establishes a procedure for testing, evaluating and classifying the ESD sensitivity of components to the defined Human Body Model (HBM).

ANSI/ESD SP5.1.1-2006 Human Body Model (HBM) and Machine Model (MM) Alternative Test Method: Supply Pin Ganging – Component Level
This standard practice (SP) document establishes an alternative test method (Supply Pin Ganging) to perform Human Body Model (HBM) or Machine Model (MM) component level ESD tests when the component or device pin count exceeds the ESD Simulator tester channels. This alternative test method is limited to components with greater than 512-pins or balls. If an ESD simulator above 512 pins is not available, then this SP can be used as a guide to ESD stress components with greater than 512 pins or balls using a lower pin count ESD simulator. For those components (e.g., ball grid array) that interconnect different power leads through common, low-resistance power and ground planes in the package, the number of power and ground leads can be reduced by ganging or grouping supply pins together on a custom test fixture board.

ANSI/ESD SP5.1.2-2006 Human Body Model (HBM) and Machine Model (MM) Alternative Test Method: Split Signal Pin – Component Level
This standard practice (SP) document establishes an alternative test method (Split Signal Pin) to perform Human Body Model (HBM) or Machine Model (MM) component level ESD tests when the component or device pin count exceeds the ESD Simulator tester channels. This alternative test method is limited to components with greater than 512-pins or balls. If an ESD simulator above 512 pins is not available, then this SP can be used as a guide to ESD stress components with greater than 512 pins or balls using a lower pin count ESD simulator. For high pin count components (e.g., ball grid array) with a large number of signal pins, the total number of pins can be reduced by splitting the signal pins into two or more equal sets or subgroups.

ANSI/ESD STM5.2-1999 Electrostatic Discharge Sensitivity Testing— Machine Model (MM) Component Level
This standard test method establishes a test procedure for evaluating the ESD sensitivity of components to a defined machine model (MM). It also provides a system of classifying the sensitivity of these components.

ANSI/ESD STM5.3.1-1999 Charged Device Model (CDM)—Component Level
This standard test method establishes the procedures for testing, evaluating, and classifying the ESD sensitivity components to a defined charged device model.

ANSI/ESD SP5.3.2-2004 Sensitivity Testing Socketed Device (SDM) Component Level
This standard practice provides a test method for generating a “Socketed Device Model” (SDM) test on a component integrated circuit (IC) device.

ANSI/ESD SP5.4-2004 Transient Latch-up Testing—Component Level Supply Transient Stimulation
This standard practice was developed to instruct the reader on the methods and materials needed to perform transient latch-up testing.

ANSI/ESD SP5.5.1-2004 Electrostatic Discharge Sensitivity Testing Transmission Line Pulse (TLP) Component Level
This standard practice defines a method for pulse testing to evaluate the voltage current response of the component under test.

ANSI/ESD S6.1-2005 Grounding
This standard specifies the parameters, materials, equipment and test procedures necessary to choose, establish, vary and maintain an Electrostatic Discharge Control grounding system for use within an ESD Protected area for protection of ESD susceptible items, and specifies the criteria for establishing ESD Bonding.

ANSI/ESD S7.1-2005 Resistive Characterization of Materials—Floor Materials
Measurement of the electrical resistance of various floor materials such as floor coverings, mats, and floor finishes is covered in this document.

ANSI/ESD S8.1-2001 Symbols—ESD Awareness
Three types of ESD awareness symbols are established by this document. The first one is to be used on a device or assembly to indicate that it is susceptible to electrostatic charge. The second is to be used on items and materials intended to provide electrostatic protection. The third symbol indicates the common point ground.

ANSI/ESD STM 9.1-2006 Footwear—Resistive Characterization
This standard defines a test method for measuring the electrical resistance of shoes used for ESD control in the electronics environment. A companion document covering foot grounders is in the draft stage.

ESD SP9.2-2003 Footwear—Foot Grounders Resistive Characterization (not to include static control shoes)
This standard practice was developed to provide test methods for evaluating foot grounders and foot grounder systems used to electrically bond or ground personnel as part of an ESD Control Program. Static control shoes are tested using ANSI/ESD STM9.1.

ESD SP10.1-2000 Automated Handling Equipment (AHE)
This standard practice provides procedures for evaluating the electrostatic environment associated with automated handling equipment.

ANSI/ESD STM 11.11-2006 Surface Resistance Measurement of Static Dissipative Planar Materials
This standard defines a direct current test method for measuring electrical resistance of static dissipative planar materials used in packaging of ESD sensitive devices and components.

ANSI/ESD STM11.12-2000 Volume Resistance Measurement of Static Dissipative Planar Materials
This standard test method provides test methods for measuring the volume resistance of static dissipative planar materials used in the packaging of ESD sensitive devices and components.

ANSI/ESD STM11.13-2004 Two Point Resistance Measurement
This standard test method measures the resistance between two points on a material’s surface without consideration of the material’s means of achieving conductivity. This test method was established for measuring resistance where the concentric ring electrodes of ESD Standard Test Method 11.11 cannot be used.

ANSI/ESD STM11.31-2006 Bags
This standard provides a method for testing and determining the shielding capabilities of electrostatic shielding bags.

ANSI/ESD STM12.1-2006 Seating—Resistive Measurement
This standard provides test methods for measuring the electrical resistance of seating used to control ESD.

ESD STM13.1-2000 Electrical Soldering/Desoldering Hand Tools
This standard test method provides electric soldering/desoldering hand tool test methods for measuring the electrical leakage and tip to ground reference point resistance and provides parameters for EOS safe soldering operation.

ANSI/ESD SP14.1-2004 System Level Electrostatic Discharge (ESD) Simulator Verification
This standard practice was developed to provide guidance to designers, manufacturers, and calibration facilities for verification and specification of the systems and fixtures used to measure simulator discharge currents.

ANSI/ESD SP15.1-2005 In-Use Resistance Testing of Gloves and Finger Cots
This standard practice provides test procedures for measuring the intrinsic electrical resistance of gloves and finger cots.

ANSI/ESD S20.20-2007 Protection of Electrical and Electronic Parts, Assemblies and Equipment (Excluding Electrically Initiated Explosive Devices)
This standard provides administrative, technical requirements and guidance for establishing, implementing and maintaining an ESD Control Program.

ANSI/ESD STM97.1-2006 Floor Materials and Footwear—Resistance Measurement in Combination with a Person
This standard test method provides for measuring the electrical resistance of floor materials, footwear and personnel together, as a system.

ANSI/ESD STM97.2-2006: Floor Materials and Footwear—Voltage Measurement in Combination with a Person
This standard test method provides for measuring the electrostatic voltage on a person in combination with floor materials and footwear, as a system.

ANSI/ESD S541-2003 Packaging Materials for ESD Sensitive Items
This standard defines the packaging properties needed to protect electrostatic discharge sensitive (ESDS) electronic items through all phases of production, transport and storage. The document discusses application requirements and references the testing methods for evaluating packaging and packaging materials for those properties.

Table 2: ESD Association Standards Documents

ESD Association Advisory documents are not standards, but provide general information for the industry or additional information to aid in better understanding of association standards.

ESD ADV1.0-2004 Glossary of Terms
Definitions and explanations of various terms used in Association Standards and documents are covered in this Advisory. It also includes other terms commonly used in the electronics industry.

ESD ADV11.2-1995 Triboelectric Charge Accumulation Testing
The complex phenomenon of triboelectric charging is discussed in this Advisory. It covers the theory and effects of tribocharging. It reviews procedures and problems associated with various test methods that are often used to evaluate triboelectrification characteristics.

ESD ADV53.1-1995 ESD Protective Workstations
This advisory document defines the minimum requirements for a basic ESD protective workstation used in ESD sensitive areas. It provides a test method for evaluating and monitoring workstations.

Table 3: ESD Association Advisory Documents

ESD TR 20.20-2000 ESD Handbook
Provides guidance that can be used for developing, implementing, and monitoring an electrostatic discharge control program in accordance with ANSI/ESD S20.20. It also includes Glossary of Terms (ESD ADV1.0-2003). This document was formerly ESD ADV2.0.

ESD TR50.0-01-99 Can Static Electricity be Measured? Author: Niels Jonassen, Technical University of Denmark, 36 Pages

ESD TR50.0-02-99 High Resistance Ohmmeters – Voltage Measurements
Authors: Steve Gerken, USAF; Ron Gibson, Celestica International; John Kinnear, IBM,
3 Pages

ESD TR15.0-01-99 ESD Glove and Finger Cots
Author: E.W. Chase, ETS, Inc, 10 Pages

ESD TR13.0-01-99 EOS Safe Soldering Iron Requirements Authors: G. Baumgartner, Lockheed Martin Missiles & Space – Retired, ESD West Consulting; Jack S. Smith, Lockheed Martin Advanced Technology Center, 19 Pages

ESD TR2.0-01-00 Consideration for Developing ESD Garment Specifications Author: G. Baumgartner, ESD West Consulting,
30 Pages

ESD TR2.0-02-00 Static Electricity Hazards of Triboelectrically Charged Garments
Author: M. Manders, United States Air Force
8 Pages

ESD TR14.0-01-00 Calculation of Uncertainty Associated with Measurement of Electrostatic Discharge (ESD) Current Authors: Working Group 14, Simulators; ESD Association,
18 Pages

ESD TR5.3.2-01-00 Socket Device Model (SDM) Tester Authors: Working Group 5.3.2, Socket Device Model; ESD Association,
22 Pages

ESD TR5.4-01-00 Transient Induced Latch-Up (TLU) Authors: Working Group 5.4, Transient Latch-Up; ESD Association, 27 Pages

ESD TR5.2-01-01 Machine Model (MM) Electrostatic Discharge (ESD) Investigation – Reduction in Pulse Number and Delay Time
Authors: M. Kelly, Delphi Delco Electronics; J. Mick, Intel Corporation; M. Chaine, Micron Technology; B. Carey, Agere Systems
27 Pages

ESD TR55.0-01-04 Electrostatic Guidelines and Considerations for Cleanrooms and Clean Manufacturing, Authors: T. Albano, Eastman Kodak; B. Baumgartner; ESD West; D. Bellmore, Universal Instrument; R. Benson, Clarient Technologies; D. Boehm, Novx; E. Davis, Vidaro Corporation; V. Gross, IBM; J. Hamlin, Qualcom; K. Kim, BF Goodrich SCP; W. Metz, Hewlett Packard; C. Newberg, River’s Edge Technical Service; J. Salisbury, Semtronics Corporation; A. Steinman, Ion Systems; G. Williams, Semtronics Corporation
26 Pages

ESD TR1.0-01-01 Survey of Constant (Continuous) Monitors for Wrist Straps
Authors: B. Beamer, Static Control Components; D. Boehm, Novx Corporation;
J. Brodbeck, USAF; L. Burich, Lockheed Martin; C. Checketts, Motorola; S. Koehn, 3M; J. Mann, Protective Solutions; J. Salisbury, Semtronics
11 Pages

ESD TR3.0-01-02 Alternate Techniques for Measuring Ionizer Offset Voltage and Discharge Time Authors: Richard Rodrigo, Simco; Arnold Steinman, Ion Systems; Merle Weight, Unisys; Donn Bellmore, Universal Instruments; Tim Jarrett, Guidant (CPI); Carl Newberg, River’s Edge; Dale Parkin, IBM; Donn Pritchard, Trek; Jeff Salisbury, Semtronics; Julius Turangan; Western Digital, 11 Pages

ESD TR10.0-01-02 Measurement and ESD Control Issues for Automated Equipment Handling of ESD Sensitive Devices Below 100 Volts Authors: Joe Bernier, Intersil; Tom Albano, Eastman Kodak; Don Boehm, Dou Yee Enterprises; John Kinnear, IBM; Donn Pritchard, Trek, Inc.; Craig Zander, Restronics ; Donn Bellmore, Universal Instruments; Brent Howard, Shuttleworth; Charles Perry, Monroe Electronics; Arnold Steinman, ION Systems
11 Pages

ESD TR4.0-01-02 Survey of Worksurfaces and Grounding Mechanisms
Authors: Dale Parkin, IBM; Ryne Allen, Desco; Brent Beamer, Static Control Components; Julius Brodbeck, USAF; Larry Burich, Lockheed Martin; Tim Jarrett, Guidant Corp.; Steve Koehn, 3M; Mike Manders, USAF; Dennis Rivers, Denclare Technologies; Bill Ricker, Kewaunee Scientific, 16 pages

ESD TR50.0-03-03 Voltage and Energy Susceptible Device Concepts, Including Latency Considerations Author: Ben Baumgartner, ESD West Consulting, 26 Pages

ESD TR3.0-02-05 Selection and Acceptance of Air Ionizers
Authors: Rick Rodrigo, Simco; Donn Bellmore, Universal Instruments Corp.; Timothy Jarrett, Guidant Corporation, Niels Jonassen, Technical University of Denmark; Carl Newberg, MicroStat Laboratories; Maciej Noras, Trek, Inc.; Dale Parkin, IBM; Jeff Salisbry, Seagate Technology; Arnold Steinman, Ion Systems, Inc; Julius Tureangan, Western Digital
17 pages

Table 4: ESD Association Technical Reports