March, 2008David E. SwensonESD Association

ESD Association Introduction, Advancements and Educational Opportunities

Presented by:David E. SwensonESD Association President 2008

Why is ESD Still Important?

• Devices with increased ESD sensitivity are arriving at Electronics manufacturing companies now

• Automated processing replacing people – shift from Human Body Model to Charged Device Model and Machine Model concerns

• Manufacturing process capability needs to keep pace with changes in device susceptibility to ESD

• The disk drive industry has had to deal with increased ESD susceptibility for years – need to keep pace with technology advances and reduction in overall cost

Changes in Device Performance

• To achieve the performance and density specifications required by industry, many types of electronic devices are becoming more sensitive to ESD

• The current trend, which is expected to continue, is to increase circuit performance at the expense of ESD protection• This is especially the case for RF circuit applications

• And, already well known in the disk drive industry

ESD Technology Road Map

• Prediction in device sensitivity by senior device designers at IBM, Texas Instruments and Intel Corporations

• Increases in device sensitivity are here now, particularly for RF components

• Road Map already assumes the increase in magneto-resistive head ESD sensitivity

Device Sensitivity RoadmapCMOS HBM (Min and Max Levels)

0

2000

4000

6000

8000

10000

1980 1985 1990 1995 2000 2005 2010

Year

HB

M V

olts

2005 level – 300 volts

2010 level – 100 volts

Copyright 2005 ESD Association

Device Sensitivity Roadmap

2005 level – 100 volts

2010 level – 50 volts

Copyright 2005 ESD Association

Device Sensitivity Roadmap

2005 level – 30 volts

2010 level – 10 voltsCopyright 2005 ESD Association

ESD Damage!

ESD damage to the IC’s can occur in different failure modes from slight to severe

ESD Latch-up ESD

ESD ESDEOS

EOS & ESD Damage

Factory Issues

• Determine the process capability• What level of device ESD sensitivity can the process

handle?• What process areas are suspect?• Can you determine fall-out from ESD?

• Is it possible to verify that the ESD controls are functioning correctly?• What are the appropriate measurement tools?

Factory Considerations - Personnel

• Relatively simple and proven methodology to establish the minimum requirements for personnel • ANSI/ESD S20.20, JESD 625A and IEC61340-5-1 all call for

<35 MΩ for personnel (100 V HBM) • IDEMA <10 MΩ (10 volts HBM)• Fairly easy to monitor these requirements• Daily (minimum) wrist strap and footwear checks

• Constant monitoring in sensitive applications• Regular floor maintenance

Wrist Strap System Resistance Test

Ground Lead

Positive Lead

Wrist Strap #304 Stainless Steel Electrode

Testing Shoe Grounder while worn

ESD Association ESD STM97.1-1999Floor Materials and Footwear –

Resistance Measurement in Combination with a Person

Stainless steel, brass or copper electrode.

ESD Association ESD STM97.2-1999Floor Materials and Footwear –

Voltage Measurement in Combination with a Person

Stainless steel, brass or copper electrode.(or wrist strap can be used.

312.6 - 1.24CHARGE PLATE MONITOR

+ -Voltage Adjust

Plate Controls

Charge Plate Monitor

8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8

Recording Device

Voltage Vs. RTG (Wrist Strap)

IDEMA Level

General factory level

Person Walking across various surfaces

Person Walking – good example

Factory Automation adds issues

• A need exists to measure charge generation, charge accumulation and ESD inside equipment -• What is happening inside the tool – fixture – assembly

line? • Goal is to qualify equipment in a similar way as

has been done for personnel in manual operations -• Quantify the electrostatic levels inside the equipment

to help establish process capability

Machine Model Concerns

• Make sure that all the metal surfaces that can come into contact with ESD sensitive devices are grounded, all the time !!!

• Need to make resistance measurements with metal parts in motion – conveyors, belts, slides – to verify that all metal parts are electrically bonded and ultimately attached to ground

Field Induced Charged Device Model

• Reduce electrical fields from the process essential insulators

• ESD sensitive devices grounded in the presence of an electrical field will charge and discharge – perhaps multiple times

Workstation Monitoring

E-Field measurements of a manual workstation installing heat-sinks on a PC Board. Large pulses when empty plastic tray removed, 1 meter away from work area

Workstation E-field

Plastic tray E-field increases as Heat Sinks are removed from tray pockets

Plastic Tray Removal

New Sensors are in development with extreme sensitivity

Induced Voltage (Experimental Data)

S20.20 Recommendation

2

0

0

0

V

O

L

T

S

Electrical Field Considerations in Disk Drive Industry

• Maximum E-field within 30 cm of any sensitive process:

500 Volts

• Not a simple requirement• Requires great care to eliminate non-essential

insulators• Use of properly applied ionization

Impact of E-Field of 500 Volts at 1 inch at various distance and sizes

Various Size Plates Charged from 500 V Power Supply at Various Distances

0

100

200

300

400

500

600

1 3 6

Distance

Fiel

d St

reng

th

Volts

@in

ch 61.50.75

Plates in Inches

Field Mill Measurement

20,000 V/m

12,000 V/m

4,000 V/m

Measuring Induction Inside Process Equipment

• Industry is developing tools and equipment for process verification• Monitor induced voltage levels inside process

equipment (Field Induced CDM)• Locate areas within equipment where discharges

occur• Help spot MM issues

49 Volts

J. Kinnear, IBMBeta Test SeriesCDM/FIM Handlers

DevicePlacement

PCB Momentarily Stopped

Courtesy of SH&A/Prostat

Process Monitoring

Electrical field measurement – Volts/meter

Circuit Board assembly

Process Monitoring

Circuit Board assembly – expanded view

Electrical Field – Volts/Meter

Process Monitoring

Circuit Board Assembly – Part Placement

Electrical Field – Volts/cm

Transition to the Next Level

• Device Design and Factory personnel must prepare to handle the increased ESD sensitivity coming soon

• Having a better understanding of ESD control techniques will be required in the factory

• Knowing how to make all the required measurements will be an essential skill in the (near) future for those that must maintain an Electrostatic Protected Area

This leads to a need for increased education

ESD Association - Professional Education

• ESD Program Manager Certification• 10 Tutorials in the education curriculum • Comprehensive 8 hour exam

• ESD Device Design Professional• 12 Tutorials in the education curriculum• Comprehensive 8 hour exam

iNarte

• The ESD Association has a renewed agreement with iNARTE to assist with their certification programs

• ESD Association tutorials are the main training materials for the ESD Technician and ESD Engineer Certifications offered by iNARTE

Certified Program Manager Tutorial Curriculum

• ESD Basics (full day)• How To’s of In-Plant ESD

Auditing and Evaluation Measurements (full day)

• ESD Program Development and Assessment (2-days)

• Device Technology and Failure Analysis Overview

• Electrostatic Calculations for the ESD Engineer

• Cleanroom considerations for the Program Manager

• System Level ESD/EMI: Testing to IEC and other Standards

• Air Ionization: Issues and Answers

• ESD Standards Overview for the Program Manager

• Packaging Principles for the Program Manager

Additional Class Relevant to the Disk Drive Industry

ESD Control for Extremely Sensitive Class “0”Devices

Certified Program Manager

• Comprehensive 8 hour exam covering all aspects/subjects taught in Tutorial program

• Essay questions – ~40% of score• Graded by two independent Program Manager

Council Members• Must pass each section with a minimum grade of

50%. Must have an overall average of >70%

Certified Program Manager

• Current iNARTE Engineers may take test without taking Tutorials• Comments received:

• Difficult test • Good test of ESD Control knowledge• Much harder than the iNARTE test• Command of English (reading and writing) a must

for essay questions

ESD Device Design Professional – Tutorial Curriculum

• ESD On-chip Protection in Advanced Technologies

• System Level ESD/EMI: Testing to IEC and other Standards

• On-Chip ESD Protection for RF Technologies

• Spice-Based ESD Protection Design Utilizing Diodes and Active MOSFER Rail Clamp Circuits

• EOS/ESD Failure Models and Mechanisms

• Circuit Modeling and Simulation for On-Chip Protection

• Latch-up Physics and Design• Device Testing-Component Level –

HBM,CDM,MM,& TLP• Impact of CMOS Technology Scaling

for ESD• CDM Design and Characterization• Troubleshooting On-Chip ESD

Failures• Transmission Line Pulse

Measurements: Parametric Analyzer for ESD On-Chip Protection

ESD Device Design Professional

• The first examination for DD Certification was offered at the 2007 (EOS/ESD Symposium)

Tutorial Offering - 2008

• The full slate of Tutorials are offered each year at the EOS/ESD Symposium • September 7-12, 2008, Westin La Paloma Resort and

Convention Center, Tucson, AZ• Selected Tutorials offered throughout the year at

ESD Association Standards/Planning meetings and co-sponsored by Local Chapters

See 2008 schedule at www.esda.org

International Tutorials

• The ESD Association is developing plans to offer Tutorials throughout the world• High interest in Asia and Europe• Working on logistics

Wrap-up

• ESD Sensitivity will increase dramatically over the next couple years for all electronic parts

• In-plant processes must improve to avoid costly losses• Education of employees involved in the ESD Control

Program is gaining in importance (again)• The Device Design community offers a new educational

package

Thank you for allowing me to deliver this message today