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ESD Control Experts
Electrical Overstress (EOS) and
Electrostatic Discharge (ESD) Event
© 2015 Desco Industries Inc.
StaticControl.com
Agenda
• EOS/ESD Basics
• EOS/ESD Instrumentation
• Applications
EOS/ESD Basics
EOS
Fig 2: Transistor failure caused by
electrical overstress damage across the
die
ESD
Fig 3: ESD damage/short between
Emitter/Collector regions on a device.
Electrical Overstress (EOS)
EOS
Note – EOS
will be
influenced by
all signals
EMI
ESD
Static
Field
RFI
EField
RFT
Induced
Voltage
Surge
© 3M 2014. All Rights Reserved.
EMF
HField
Important Terms
• EOS: Electrical Overstress
• Static Field: Electrostatic Field
• Induced Voltage: Voltage induced into the board or
component by contact
• ESD: Electrostatic Discharge
• EMI: Electromagnetic Interference
• EMF: Electromagnetic Field
• E-Field: Electric Field
• RFI: Radio Frequency Interference
• EFT: Electronics Fast Transients
• H-Field: Magnetic Field
• Surge: A sudden, sharp increase of electric current or
voltage in a circuit
What is Electrical Overstress (EOS)?
• EOS (Electrical
Overstress) is the
exposure of a
component or PCB
board to a current
or voltage beyond
its maximum
ratings. This
exposure may or
may not result in a
catastrophic failure.
Fig 4: EOS on a damaged RS232C transceiver
How is Static Generated?
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-
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Contact and Separation of
Materials
© 3M 2014. All Rights Reserved.
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What is Induced Voltage?
• Refers to voltage
being induced into
the board or
component by
contact, resulting in
current transfer
through the
component or
board.
Fig 5: Current flow resulting from Induced
Voltage
What is Electrostatic Discharge (ESD)?
• ESD is a rapid, spontaneous
transfer of electrostatic charge
induced by a high electrostatic
field through a spark between
two bodies at different
electrostatic potentials as they
approach or are separated
from one another.
• There are three different ESD
models identified by the
standards presently:
− Charge Device Model (CDM)
− Machine Model (MM)
− Human Body Model (HBM)
Fig 6: ESD damage to a bi-polar
transistor
What is Electromagnetic Interference (EMI)?
• Electromagnetic
Interference is a
disturbance that
affects an electrical
circuit, due to either
electromagnetic
induction or
electromagnetic
radiation emitted from
an external source.
Fig 7: Electromagnetic Interference
What is Electromagnetic Field (EMF)?
• Electromagnetic Field is
a physical field produced
by electrically charged
objects. It affects the
behavior of charged
objects in the vicinity of
the field. The
electromagnetic field
extends indefinitely
throughout space.
Fig 8: Electromagnetic Field
from a Cell Phone
What is Electric Field (E-Field)?
• Electric field
surrounds electrically
charged
particles. Electric
field exerts a force on
other electrically
charged objects.
Fig 9: Electric Field from
positive and negative charge
What is Radio Frequency Interference (RFI)?
• Radio Frequency
Interference (RFI) refers
to the noise caused by
other Radio Frequency
that interferes with
information being
transmitted.
Fig 10: TDMA mobile phone caused false readings
in sensor of magnetic head tester and finally caused
error message after failing several good GMR
heads
What is Electrical Fast Transient (EFT)?
• An Electrical Fast
Transient event is a
short-lived burst of
energy in a system
caused by a sudden
change of state. The
source of the transient
energy may be an
internal event or a nearby
event.
Fig11: Single and bursts of EFT
What is a Magnetic Field (H-Field)?
• A magnetic field is a field
of force produced by
moving electric
charges. Electric and
magnetic fields are two
interrelated aspects of a
single object, called
the electromagnetic field.
Fig12: Magnetic Field penetrating a
superconductor
What is a Power Surge?
• A Power Surge is an
unexpected, temporary,
uncontrolled increase in
current or voltage in an
electrical circuit. Heavy
electrical equipment
being cycled on/off is
the most common cause
of power surge.
Fig 13: Power Surge and its effect
SCS Products Used for Each Parameter
• EOS: SCS Iron Man Plus Workstation Monitor
• Static Field: SCS Air Ionizer Tester/Field Meter and Charger 718 or
SCS EM Aware TNG ESD Event Monitor
• Induced Voltage: (from ground) SCS Ground Pro Ground Integrity
Meter, SCS Ground Master, and (by contact) SCS Charge
Analyzer/Charge Monitor 711
• ESD: EM Aware TNG ESD Event Monitor, SCS EM Eye Meter,
SCS ESD Pro Event Indicator
• EMI: EM Eye Meter
• EMF: EM Eye Meter
• E-Field: EM Eye, ScanEM-C
• RFI: EM Eye Meter
• EFT: EM Aware TNG ESD Event Monitor, EM Eye Meter
• H-Field: ScanEM-C
What Constitutes a Safe EOS/ESD Environment?
• The ultimate goal of an EOS/ESD program is to minimize EOS/ESD
exposure to components and its influence on the process.
• Without closed-loop control, the success of an EOS/ESD program is
always uncertain.
• Most current ESD controls are centered on performance of
individual components of ESD protection, such as grounding,
ionizers, materials, etc.
• If EOS/ESD occurred in your environment, performance of
individual protection components is lacking.
AN EOS/ESD Program is Only As Strong as its Weakest Link...
It Is Imperative to Address All Potential Areas of Damage
What Constitutes a Safe EOS/ESD Environment?
• The Most Ionizers
+
• The Best Ground
+
• Everyone Wearing Wrist Straps
+
• Compliance with ESD Standards
A Safe EOS/ESD
Environment is One
Where There is No
EOS/ESD Exposure
to Sensitive
Environments. This
Requires a Holistic
Approach.
It is Important to Address Each Component of EOS/ESD Control…
It is Equally Important to Monitor Your EOS/ESD Environment
EOS/ESD Instrumentation:
Managing Your EOS/ESD
Environment by Results
Detecting EOS/ESD Events in Your Production
• Identify and measure EOS and ESD
• Instrumentation helps ensures compliance
• Products used:
− SCS Iron Man Plus Workstation Monitor
− SCS EM Aware TNG ESD Event Monitor
Starter Kit
− SCS EM Eye Meter
− SCS ESD Pro Event Indicator
SCS Iron Man™ Plus Workstation Monitor
• Monitors:
− Electrical Overstress on the
grounded board
− Dissipative Ground (bench mat)
− Operator Resistance and Body
Voltage
• Advantages:
− Ensures compliance with EOS
levels
− Operator Body Voltage
measurement
− 10^9 Mat resistance
measurement
− Small and easy to use
Set
GNDIron Mat
U.S. Pat. 6,930,612
SCS EM Aware TNG ESD Event Monitor
• Monitors:
− Electrostatic Discharge (ESD)
− Static Field or Ionization Balance
− Ionization Decay
• Advantages:
−
−
−
−
−
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−
Measures all parameters through one antenna
Rejects non-ESD EMI events
LCD display for easy local viewing
MODBUS or 4-20mA output to FMS
Software available for characterization of ESD Events
Small footprint and Joystick for ease of use
Used for continuous monitoring of ESD, Static Field
and Ionization Decay of production environment
3M™ EM Aware TNG ESD Event Monitor Starter Kit
• Diagnostic/Audit Tool:
− ESD
− Static Field or
Ionization Balance
− Ionization Decay
• Advantages:
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−
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Measures multiple points (up to 6 units)
Complete with data acquisition and software for recording
Used as ESD diagnostic tool for different applications
Supplies factual data during Diagnostic and ESD Audit
ESD Audit: Going by the Facts
ESD Audit Report
• Assumptions
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Wrist straps 
Ground 
Ionizers 
Dissipative floors 
Dissipative garments 
Static voltage levels 
Gloves 
Tweezers 
Packaging 
Shelving 
ESD Audit Report
• Facts
−
12 ESD Events stronger
than 200V CDM observed
at tool # 5 during 8 hrs.
shift
−
Maximum strength of ESD
Event was 550V CDM
−
ESD Events were
correlated with new
materials arrival and
handling
−
Correction and verification
to follow immediately
SCS EM Eye Meter
• Measuring Instrument:
− Electrostatic Discharge (ESD) – CDM, HBM, MM
− Electromagnetic Field (EMF)
− RF Signal
• Advantages:
− Portable, light weight, touch screen
− Open platform – use specific sensor for
specific parameter.
− Used as ESD diagnostic instrument
− Rejects non-ESD EMI events
− Supplies factual data during ESD Audit
− Uses directional antenna or remote antenna
− Supplied with Calibration Certificate
SCS ESD Pro ESD Event Indicator
• Diagnostic Tool:
− Electrostatic Discharge (ESD)
• Advantages:
− ESD Indicator
− Displays strength of ESD Event
− Used as ESD diagnostic tool for different
application
− Supplies factual data during ESD Audit
− Portable and easy to use
− Rejects non-ESD EMI events
Identifying Root Causes
At the Application Level
Finding the Root Causes of EOS/ESD
• Identify the Application Where EOS/ESD Events
are Being Created
• For Example…
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−
−
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SMT Line
Soldering
Printer
Repair
Functional Test (Manual or Automatic Testing)
Manual Applications
Must Know Where to Look…
3M Expertise and Technology Can Help
EMI influence on EOS
•
Common Mode and Differential mode signals
•
Powerful Linear Servo-Motors used to move feeders or
robotic arms on an Automated tool
No filter
I=1.562
A
Servo
Filter
I=0.0069A
IC Handlers
• Discharges Happen When:
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−
−
−
−
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IC is picked up from the input tray
IC is placed in the input shuttle
IC is placed in the test socket
IC is lifted from the test socket
IC is placed in the exit shuttle
IC is placed in the output tray
Pick and Place
• Discharges Happen When:
− IC is picked up from the tape and reel
− IC is picked up from the tray
− IC is placed on the board
Mechanism of EOS/ESD Damage in Handlers
or Pick & Place
Ionizer
This Scenario Covers the
Discharge Resulting from
the Tribocharging of
Encapsulation of the IC
Ionizer
attempts to
dissipate
charge on the
IC
IC is being
moved
Tribocharge is
created on the IC
when IC is lifted
IC retains
significant
charge
Discharge when IC
touches the surface
Soldering and Soldering Extract
• CDM or CBE Discharges Happen When:
− Board travels and touches a grounded
soldering wave
− Soldering tip touches the component or the
board
− Solder touches the board
− Component separation from board during
extract application
Data Received from Wire Bonding
Wire Bonder ESD
pattern with the same
spacing during
production.
Dual ESD Event other then
Wire Bonder pattern during
production.
Data Received from Multitester
• ESD Events Detected At:
− Multitest #6
Dispenser
− Multitest #6 Q-Test
• The lowest ESD Event
detected on channel 1
was 38V CDM and the
highest ESD Event
detected on channel 1
was >500VCDM
• The lowest ESD Event
detected on channel 3
was 19V CDM and the
highest ESD Event
detected on channel 3
was 240VCDM
• Static Voltage is higher at
the Q-Test area
When operator is not testing the chips
no ESD Events are detected in the area
• Static Voltage at the
dispenser area is
normally low with the
exception when parts are
put in the dispenser
Safe EOS/ESD Environment Based on Results
• All EOS/ESD Protective Measures are
Designed to Prevent EOS/ESD Events
• By Managing EOS/ESD by Protective
Measures, You ASSUME that Your
EOS/ESD Problems are Solved
• By Monitoring Your Environment and
Managing EOS/ESD by End Results, You
KNOW that EOS/ESD Problems are Solved
SCS Products & Services: Putting it All Together
• Products
− Instrumentation for monitoring and detection of ESD/EOS events
− Workstation Products for prevention of ESD/EOS events during mfg
− Bags for prevention of ESD/EOS events during transit
• Services
− Step 1: Audit/Assessment of facilities by certified SCS ESD/EOS
expert
− Step 2: Detailed in-person training for your ESD managers and
coordinators
− Step 3: High-level training for operators and managers
− Step 4: Continuous monitoring and support by SCS ESD/EOS
experts
SCS is Not Just a Supplier, but a Collaborator…
…And Your Competitive Advantage