march, 2008 david e. swenson esd association · david e. swenson esd association president 2008....
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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