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Now is the Time for ESD Control Programs to be Improved

Originally Published by InCompliance Magazine- September 2012
“By Fred Tenzer and Gene Felder”

ElectroStatic Discharge (ESD) is the hidden enemy within your factory. You cannot feel or see most ESD events but they can cause electronic components to fail or cause mysterious and annoying problems. There are two types of ESD damage: 1) Catastrophic failures, and 2) Latent defects. By definition, normal quality control inspections are able to identify catastrophic failures, but are not able to detect latent defects.

In general, the ESD susceptibility of modern electronics are more sensitive to ElectroStatic Discharge; that is the withstand voltages are lower. This is due to the drive for miniaturization particularly with electronic devices operating faster. Thus the semiconductor circuitry is getting smaller. For example Intel began selling its 32 nm processors in 2010 that would be 0.032 micrometer equal to 0.000032 millimeter or 0.00000128 inch.

For more information on ESD and the direction of electronics manufacturing, see the articles listed below.

Evaluation Engineering Magazine November 2001 article “ESD Control Program Development” “As the drive for miniaturization has reduced the width of electronic device structures to as small as 0.10 micrometer (equal to 0.0001 millimeter or 0.000004 inch), electronic components are being manufactured with increased ElectroStatic Discharge (ESD) susceptibility.”

www.ESDA.org, the ESD Association’s latest White Paper “Electrostatic Discharge (ESD) Technology Roadmap – Revised April 2010” forecasts increased ESD sensitivities continuing the recent “trend, the ICs became even more sensitive to ESD events in the years between 2005 and 2009. Therefore, the prevailing trend is circuit performance at the expense of ESD protection levels.” The White Paper’s conclusions are:

“With devices becoming more sensitive through 2010-2015 and beyond, it is imperative that companies begin to scrutinize the ESD capabilities of their handling processes. Factory ESD control is expected to play an ever-increasing critical role as the industry is flooded with even more HBM and CDM sensitive designs. For people handling ESD sensitive devices, personnel grounding systems must be designed to limit body voltages to less than 100 volts.

To protect against metal-to-device discharges, all conductive elements that contact ESD sensitive devices must be grounded.

To limit the possibilities of a field induced CDM ESD event, users of ESD sensitive devices should ensure that the maximum voltage induced on their devices is kept below 50 volts.

To limit CDM ESD events, device pins should be contacted with static-dissipative material instead of metal wherever possible.”

InCompliance Magazine May 2010 article by Dr. Terry L. Welsher The “Real” Cost of ESD Damage which includes “Recent data and experience reported by several companies and laboratories now suggest that many failures previously classified as EOS may instead be the result of ESD failures due to Charged Board Events (CBE). … Some companies have estimated that about 50% of failures originally designated as EOS were actually CBE or CDE.”

Charleswater

For additonal technical information Click Here

To read the rest of the article go to Now is the Time for ESD Control Programs to be Improved

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What is a Faraday Cage?

by Gene Felder


A Faraday cage or Faraday shield is an enclosure formed by conducting material or by a mesh of such material. Such an enclosure blocks external static and non-static electric fields. Faraday cages are named after the English scientist Michael Faraday, who invented them in 1836. An impressive demonstration of the Faraday cage effect is that of an aircraft being struck by lightning. This happens frequently, but does not harm the plane or passengers. The metal body of the aircraft protects the interior. For the same reason, a car may be a safe place to be in a thunderstorm.


ESD control products that provide a Faraday Cage or shielding include Charleswater Statshield® Metal-In Bags, and Statshield® Metal-Out Bags, Protektive Pak™ impregnated corrugated with shielding layer when using a lid, and Conductive Totes. Charleswater ESD Lab Coats create a Faraday Cage effect around the torso and arms of the operator and shields charges from the operator’s clothing from damaging ESD sensitive devices. (Technically, suppressing the electrical field from clothing worn underneath).


There are standard tests measuring the energy penetration of electrostatic discharges to the interior. The Shielding test method per EN 61340-5-1 Packaging table 4 is ANSI/ESD STM11.31 and the required limit is less than 50 nanoJoules of energy.


The EN 61340-5-1 Edition 1.0 2007-08 Introduction includes “ESD protection can be achieved by enclosing ESD sensitive products in static protective materials, although the type of material depends on the situation and destination. Inside an EPA, low charging and static dissipative materials may provide adequate protection. Outside an EPA, low charging and static discharge shielding materials are recommended.” []

Definitions:
Faraday cage
“A conductive enclosure that attenuates a stationary electrostatic field.”

Electrostatic discharge (ESD) shield
“A barrier or enclosure that limits the passage of current and attenuates an electromagnetic field resulting from an electrostatic discharge.”

Electrostatic shield
“A barrier or enclosure that limits the penetration of an electrostatic field.”

Note: EN 61340-5-1 Edition 1.0 2007-08 can be purchased from the IEC website.

Developing an ESD control program plan per CLC/TR 61340-5-2:2008

From ESD User guide CLC/TR 61340-5-2:2008 clause 4.1:

This clause outlines a step-by-step approach that can be used to establish an ESD control program.

4.1 Developing an ESD control program plan

4.1.1 Assignment of an ESD coordinator

In order to have a well thought out and implemented ESD program an ESD coordinator must be assigned. The ESD coordinator is responsible for all aspects of ESD in the facility. In order to be effective the ESD coordinator needs:

  1. the full support of management
  2. a good understanding of electrostatics and how ESD sensitive devices can be damaged. The ESD coordinator will often need to attend educational classes or seminars related to ESD in order to maintain or update their knowledge
  3. a thorough understanding of IEC 61340-5-1 and all of the organization’s processes related to the handling of ESD sensitive devices
  4. access to measuring equipment for the purposes of performing compliance verification audits as well as testing new ESD products and materials for use in the ESD program
  5. depending on the size of the facility, the ESD coordinator might also need to have auditors assigned to conduct the ESD audits

Finally, management must provide the ESD coordinator with the authority and funding necessary to ensure that the ESD control program is maintained and enforced.

4.1.2 Determination of part ESD sensitivity

The next step in developing an ESD control program plan is to determine the part, assembly or equipment sensitivity level under which the plan is to be developed. Although the requirements outlined in IEC 61340-5-1 are effective for handling parts sensitive to 100 V HBM or higher, the organization may choose to develop an ESD program based on ESD sensitivities that are greater or less than 100 V HBM. In this situation, the organization must develop an ESD control program plan that clearly states the ESD sensitivity that the program is based on. The organization can use various methods to determine the ESD sensitivity of the products that are to be handled. Some of the methods include: assumption that all ESD products have an HBM sensitivity of 100 V; actual testing of ESD sensitive devices to establish the ESD sensitivity thresholds using IEC 60749-26; referencing ESD sensitivity data in published documents such as manufacturer’s published data sheets.

4.1.3 Initial process and organizational assessment

Before the ESD control program plan can be developed, an initial assessment of the processes and organizations impacted by an ESD control program should be conducted. Organizations and processes that might be affected include:

  • purchasing
  • design engineering
  • receiving inspection
  • quality assurance
  • manufacturing
  • testing
  • maintenance
  • packaging and shipping
  • field service
  • failure analysis
  • repair services
  • spare parts storage
  • material handling and parts conveyance
  • receiving

An assessment of each area where ESDS parts are handled should be conducted in order to determine ESD hazards and possible ESD process procedures. The information accumulated throughout these steps forms the basis for developing the ESD control program plan.

4.1.4 Documentation of ESD control program plan

After gathering the above information, the organization is in a position to begin documenting the program plan. The plan should state the scope of the program which includes the tasks, activities and procedures necessary to protect the ESD sensitive items at or above the ESD sensitivity level chosen for the plan. Although the primary focus of the plan is to outline strategies for meeting the administrative and technical elements of IEC 61340-5-1, other items may be beneficial to incorporate as well. These additional items might include:

  • organizational responsibilities
  • defined roles and responsibilities between the organization and subcontractors and suppliers
  • strategies for monitoring product yields and processes that might be important in determining the effectiveness of ESD control measures currently in place or in assessing whether additional measures should be taken
  • approaches for ensuring continual improvement of the ESD program
  • a list of approved ESD control products and materials.

The administrative and technical elements of IEC 61340-5-1 that need to be addressed in the plan (unless tailored) include:

  • training plan
  • compliance verification plan
  • technical requirements
  • grounding bonding systems
  • personnel grounding
  • protected areas
  • packaging
  • marking

Charleswater – your ESD Control Experts. Contact Customer Service for help with your ESD Control Programme.

ESD Control Programs Should be Improved

ElectroStatic Discharge (ESD) is the hidden enemy within your factory. You cannot feel or see most ESD events but they can cause electronic components to fail or cause mysterious and annoying problems. There are two types of ESD damage: 1) Catastrophic failures, and 2) Latent defects. By definition, normal quality control inspections are able to identify catastrophic failures, but are not able to detect latent defects.

In general, the ESD susceptibility of modern electronics are more sensitive to ElectroStatic Discharge; that is the withstand voltages are lower. This is due to the drive for miniaturization particularly with electronic devices operating faster. Thus the semiconductor circuitry is getting smaller.

See November 2001 Evaluation Engineering Magazine article “ESD Control Program Development” “As the drive for miniaturization has reduced the width of electronic device structures to as small as 0.10 micrometer (equal to 0.0001 millimeter or 0.000004 inch), electronic components are being manufactured with increased ElectroStatic Discharge (ESD) susceptibility.”

What’s happening currently? Intel began selling its 32 nm processors in 2010 that would be 0.032 micrometer equal to 0.000032 millimeter or 0.00000128 inch.

See www.ESDA.org, the ESD Association’s latest White Paper “Electrostatic Discharge (ESD) Technology Roadmap – Revised April 2010” forecasts increased ESD sensitivities continuing the recent “trend, the ICs became even more sensitive to ESD events in the years between 2005 and 2009. Therefore, the prevailing trend is circuit performance at the expense of ESD protection levels.” The White Paper’s conclusions are:

“With devices becoming more sensitive through 2010-2015 and beyond, it is imperative that companies begin to scrutinize the ESD capabilities of their handling processes. Factory ESD control is expected to play an ever-increasing critical role as the industry is flooded with even more HBM and CDM sensitive designs. For people handling ESD sensitive devices, personnel grounding systems must be designed to limit body voltages to less than 100 volts.

To protect against metal-to-device discharges, all conductive elements that contact ESD sensitive devices must be grounded.

To limit the possibilities of a field induced CDM ESD event, users of ESD sensitive devices should ensure that the maximum voltage induced on their devices is kept below 50 volts.

To limit CDM ESD events, device pins should be contacted with static-dissipative material instead of metal wherever possible.”

See InCompliance Magazine May 2010 article by Dr. Terry L. Welsher The “Real” Cost of ESD Damage which includes “Recent data and experience reported by several companies and laboratories now suggest that many failures previously classified as EOS may instead be the result of ESD failures due to Charged Board Events (CBE). … Some companies have estimated that about 50% of failures originally designated as EOS were actually CBE or CDE.”

Charleswater

For additonal ESD information Click Here

ESD Control, Return on Investment

Ryne C. Allen

Desco Industries Inc. (DII), Employee Owned

November 1999

Reproduced with Permission, EE-Evaluation Engineering, November, 1999

INTRODUCTION

I. Introduction to ESD Control Programs

ESD Control programs are an essential part of a quality process and are always needed when handling ESD sensitive electronic/semiconductor devices. The extent of the ESD Control program is determined by the ESD Sensitive (ESDS) devices themselves and how they are handled. Refer to article “How to Set Up an ESD Control Program” [1] for additional information.

One of the main reasons that companies deploy ESD Control programs is to save money. Increased throughput and decreased scrap can yield a Return On Investment (ROI ) of up to 1,000% per [2]. A secondary reason is to comply with their customers’ and ISO 9000 type programs’ requirements. Whatever reason, setting up and implementing an ESD Control program will almost always produce favorable financial results.

II. Cost Reduction via ESD Control Programs

Having ESD awareness and following through with an ESD Control program is essential in reducing quality failures due to ESD. ESD can affect product reliability with catastrophic damage which is readily apparent to latent degradation. Latent degradation is particularly expensive requiring costly inspection and rework cycles in-house or product failure in the field. Maintaining good ESD controls will improve product throughput or yield, increasing reliability in the field which improves customer satisfaction leading to increased future business.

One test equipment manufacturer noted that GMR heads were being damaged during or after testing. These heads are extremely sensitive to ESD, and require additional handling precautions.

It is very important when designing and implementing an ESD Control program to know the ESD susceptibility of the ESD Sensitive (ESDS) devices you are trying to protect. Classification of these devices should include all simulation models human body model (HBM), Machine Mode (MM), and Charged-device Model (CDM) that will properly characterize the devices’ sensitivity when handled at various locations within the facility [6]. This will allow for the most economical program design.

Gene Chase, an ESD Consultant with ETS Inc., is quoted as saying “Millions of dollars are lost every year due to ESD [4]. Many of these incidents occur within the computer and communications industry.” Examples of losses from ESD may be any of the following:

  • Lost Time
  • Loss of Connection
  • Loss of Data
  • Shocks to Personnel
  • Upset to A System Requiring A Re-Boot
  • Damage to Equipment
  • Equipment Hardware Failure

To properly determine the return on investment (ROI) from your ESD Control program, you must collect return, repair and scrap cost data before and after implementation.

To continue reading ESD Control, Return on Investment Click Here.