Esd

Transcript

ESD Course Dr. Lim Soo King BSc (Hons)(Lond); Dip. Mgt (Dist)(MIM); MSc (Mal); PhD (Mal); MIPM Associate Professor Universiti Tunku Abdul Rahman Dr. Lim Soo King 1 ESD Course Objectives of the Course
Understand the phenomena of ESD.
Mechanism of ESD Process.
Identify ESD materials.
Ability to set-up the prevention and protection scheme for ESD occurrence.
Understand the ESD protection design for circuit.
Continuous improving process in ESD monitoring.
Be a trainer. Dr. Lim Soo King 2 ESD Course Outline of the Course Introduction and Overviews
History.
ESD Failure Rate.
World Semiconductor Production.
Field Return Rate.
National Technology Roadmap for Semiconductor.
Picture Illustrating ESD Failure.
Evolution and Interpretation.
What is ESD? Dr. Lim Soo King 3 ESD Course Outline of the Course Materials and Environment
Material properties.
Movement and discharge time.
Temperature and relative humidity. Dr. Lim Soo King 4 ESD Course Outline of the Course Mechanism of ESD
Electrification.
Induction.
Gas discharge.
Chargeability.
Triboelectric series.
Causes of ESD .
Factors influencing static charge generation. Dr. Lim Soo King 5 ESD Course Outline of the Course ESD Failure Mechanism
How does static electricity damage a circuit?
Effects of ESD damage. Dr. Lim Soo King 6 ESD Course Outline of the Course ESD Reliability Test
Classification of ESD susceptibility.
Models of ESD reliability test. Dr. Lim Soo King 7 ESD Course Outline of the Course Prevention and Protection
Principles of Static Control.
Setting up ESD requirement production line.
Handling and storage of ESD sensitive parts.
Electrostatic protected area.
Good practice in ESD work area.
Audit. Dr. Lim Soo King 8 ESD Course Outline of the Course ESD Materials Identification and Selection
Material structures and properties.
Criteria of selection.
Material design physics. Dr. Lim Soo King 9 ESD Course Outline of the Course ESD Materials Monitoring/Measurement Tools and Awareness Label
ESD materials.
Monitoring tools.
Prevention materials.
Protection materials. Dr. Lim Soo King 10 ESD Course Outline of the Course Circuit Design Protection
Approach.
Methods employed for design protection and prevention. Dr. Lim Soo King 11 ESD Course Outline of the Course Case Study
Self audit. Assessment
Twenty questions. Discussion Dr. Lim Soo King 12 ESD Course Introduction and Overviews
History.
ESD Failure Rate.
World Semiconductor Production.
Field Return Rate.
National Technology Roadmap for Semiconductor
Picture illustrating ESD Failure.
Evolution ad Interpretation.
What is ESD? Dr. Lim Soo King 13 ESD Course History
In 1400’s ESD procedure was installed to prevent electrostatic discharge ignition of black gun power in Europe and Caribbean.
In1860, it was used to prevent fire and during drying process in paper mill.
In modern world, ESD control is employed in many areas such as ship yard, paper industry, assembly plant, microelectronics industry, and others. Dr. Lim Soo King 14 ESD Course ESD Failure Rate Descriptions Min. Loss 4% Max. Loss 97 % Est. Avg. Loss 16 – 22 % Subcontractor 3% 70 % 9 – 15 % Contractors 2% 35 % 8- 14 % User 5% 70 % 27 – 33 % Component Manufacturer Dr. Lim Soo King 15 ESD Course World Production of Semiconductor 250 Bil $ 200 150 100 50 0 '86 '90 '92 '94 '96 '98 '00 '02 '05 '06 Dr. Lim Soo King 16 ESD Course Field Return Failure Mode Dr. Lim Soo King 17 ESD Course National Technology Roadmap for Semiconductor Year Channel length (µ µm) 99 0.18 (0.18) 02 05 08 11 0.13 0.10 0.07 0.050 (0.13) (0.065) (0.045) - 14 0.035 - Equivalent oxide thickness (µ µm) 1.9 2.5 1.5 1.9 1.0 1.5 0.8 1.2 0.6 0.8 0.5 0.6 Transistor density (cm2) 6.6 M 18 M 44 M 109 M 269 M 664 M Red is actual channel. Dr. Lim Soo King 18 ESD Course Pictures of ESD Failure Dr. Lim Soo King 19 ESD Course Picture of ESD Failure Junction spiking Dielectric Breakdown Dr. Lim Soo King 20 ESD Course Picture of ESD Failure Diffusion damage Dr. Lim Soo King 21 ESD Course Picture of ESD Failure Dr. Lim Soo King 22 ESD Course Picture of ESD Failure Base-emitter region Dr. Lim Soo King 23 ESD Course Picture of ESD Failure Secondary breakdown Metallization Burn Dr. Lim Soo King 24 ESD Course Evolution and Interpretation Intentionally left blank Dr. Lim Soo King 25 ESD Course What is ESD?
ESD is defined as electrostatic discharge.
It is a process of electron transfer between materials. Dr. Lim Soo King 26 ESD Course What is ESD?





Insulator is the main contributor of ESD. It is a material that conducts very small amount of electricity. Once the material loses or acquires electron, the electron equilibrium state remains for a long time. Material loses electron has net positive charge. Material acquires electron has net negative charge. The most common way of generating static electricity is friction (contact and separate). Dr. Lim Soo King 27 ESD Course What is ESD?
Induction by EM interference causing polarization of charge to other material at the polarized end. Example of such source is high tension terminal.
When two materials come in contact and separate, static electricity will be generated.
When the charge material comes in contact with another material, transfer of electron would occur resulting damage to the material. Dr. Lim Soo King 28 ESD Course Balance of Charge Dr. Lim Soo King 29 ESD Course Transfer of Charge After Separation Intentionally left blank Dr. Lim Soo King 30 ESD Course Transfer of Charge After Separation Dr. Lim Soo King 31 ESD Course Generation of Static Charge by Separation Intentionally left blank Dr. Lim Soo King 32 ESD Course Generation of Static Charge by Separation Dr. Lim Soo King 33 ESD Course Materials and Environment
Material properties.
Movement and discharge time.
Temperature and relative humidity. Dr. Lim Soo King 34 ESD Course Material Properties
Conductor Conduct good electricity. Low resistance. No band-gap.
Semiconductor Conduct small amount of electricity. Dr. Lim Soo King 35 ESD Course Material Properties Moderate resistance. Narrow band-gap.
Insulator Conduct very small amount or no electricity. High resistance Large band-gap Dr. Lim Soo King 36 ESD Course Band-gap of Insulator Dr. Lim Soo King 37 ESD Course Band-gap of Conductor Intentionally left blank Dr. Lim Soo King 38 ESD Course Discharge Time Using Human Body Model Resistance Time (ms) 102 Ω 92 ns 103 Ω 2.0 µs 106 Ω 920 µs 107 Ω 9.2 ms 108 Ω 76.6 ms Resistance 109 Ω 1010 Ω 1011 Ω 1012 Ω 1013 Ω Time (ms) 92 ms 920 ms 92 s 920 s 2.5 hrs Dr. Lim Soo King 39 ESD Course Movement time of Typical Operation Intentionally left blank Dr. Lim Soo King 40 ESD Course Temperature and Relative Humidity
High temperature, high thermionic emission.
High relative humidity, more dissociation of water molecule, less charge generation.
Reduce surface resistivity.
Increase surface conductivity. Dr. Lim Soo King 41 ESD Course Typical Electrostatic Voltage at Different RH Means of Static Generation 10 - 20% 65 – 90 % at Room Temperature Walking across carpet Walking over vinyl floor Worker at bench Vinyl envelope Poly bag Chair padded with poly ethane foam. Dr. Lim Soo King 35,000 12,000 6,000 7,000 20,000 18,000 1,500 250 100 600 1,200 1,500 42 ESD Course Surface Resistivity versus RH at 25C Intentionally left blank Dr. Lim Soo King 43 ESD Course Mechanism of ESD
Electrification.
Induction.
Gas discharge.
Chargeability.
Triboelectric series.
Causes of ESD .
Factors influencing static charge generation. Dr. Lim Soo King 44 ESD Course Electrification Materials in Contact A + - + - + - + - + - + - B Helmholtz Interface (10 nm) Dr. Lim Soo King 45 ESD Course Intentionally left blank Dr. Lim Soo King 46 ESD Course Materials Separation A Point of Neutralization + - + - + - + - + - + - Dr. Lim Soo King B 47 ESD Course
The interface gap increased many folds.
Capacitance decreased many folds.
Potential difference between positively and negatively charged layers increased tremendously.
Electric field is extremely high.
Neutralization tends to happen due to gas discharge.
Gas discharge if electric field is greater than 3 MV/m.
Neutralization depends on rate of separation, surface resistivity of material, temperature and humidity. Dr. Lim Soo King 48 ESD Course Materials After Separation Intentionally left blank Dr. Lim Soo King 49 ESD Course Electrostatic Induction Position of Neutral Objects Dr. Lim Soo King 50 ESD Course Electrostatic Induction Positive charge induced on conductor Dr. Lim Soo King 51 ESD Course Electrostatic Induction Grounding conductor to remove negative charge Dr. Lim Soo King 52 ESD Course Electrostatic Induction Moving away charged sphere, redistribution of positive charge Dr. Lim Soo King 53 ESD Course Electrostatic Induction Positive charge remains on conductor Dr. Lim Soo King 54 ESD Course Electrostatic Discharge Intentionally left blank Dr. Lim Soo King 55 ESD Course Electrostatic Discharge
Inhomogeneous field gas discharges occur first at the strongest part of the field when it is sufficient to cause an avalanche.
Small surface high electric field.
Breakdown of air closed to pointed electrode.
Glow is usually observed in dark caused by relaxation of atom from excited state with emission of photons.
Violet color is nitrogen and red color is oxygen. Dr. Lim Soo King 56 ESD Course Type of Electrostatic Discharge
Corona discharge.
Spark discharge.
Flash lightning. Dr. Lim Soo King 57 ESD Course Corona Discharge Charged object Electric field Corona needle point - A Dr. Lim Soo King 58 ESD Course Corona Discharge
Presence of electric field.
As the pointed needle is closed to charged conductor, the electric field builds up.
Ionization (corona) occurs when reaches critical field (3 MV/m).
Positive and negative ions generated.
Color visual light can be observed.
Micro-ammeter will register current.
Corona discharge can be occurred with applied high potential to pointed needle.
This principle is used to eliminate static charge. Dr. Lim Soo King 59 ESD Course Demonstration of Corona Discharge Corona discharge Dr. Lim Soo King 60 ESD Course Spark Discharge
Discharge between flat metallic electrodes. Capacitor Dr. Lim Soo King Metallic plate 61 ESD Course Chargeability Versus Surface Resistivity Intentionally left blank Dr. Lim Soo King 62 ESD Course Trioelectric Series
It determines how different materials compare with their tendency to lose or acquire electron when one in contact and separation with another.
It is a table showing the order of charge type acquired by the common insulating materials.
It is a prediction of the charge polarity.
If wool comes in contact with PVC and separate, wool would lose electron and PVC would gain electron. Dr. Lim Soo King 63 ESD Course Trioelectric Series Positive (donor) + Human hands Rabbit fur Glass Polyamide Nylon Wool Silk Aluminum Paper Steel Neutral 0 Cotton Dr. Lim Soo King 64 ESD Course Trioelectric Series continues Wood Hard rubber Brass Silver Sealing wax Polyester Polyethylene PVC Silicon Negative (acceptor) - Teflon Dr. Lim Soo King 65 ESD Course Trioelectric Series
Material with high relative permittivity tends to lose electron easier than material with low relative permittivity.
High surface conductivity, less charge. Dr. Lim Soo King 66 ESD Course Triboelectric -Relative Permittivity Intentionally left blank Dr. Lim Soo King 67 ESD Course Typical Source of Static Generator in MFG Area Work surface Floor Clothes Chair Packaging and handling Assembly Cleaning Test Repair Waxed, painted or varnished surface. Common vinyl or plastic. Sealed concrete or sheeting. Synthetic personal garments. Finished wood. Fiber glass. Plastic, bag, wraps, envelope, boxes, trays, bubble pack. Spray cleaner, ungrounded solder iron, brushes, sand blasting, heat gun, temperature chamber, and etc. Dr. Lim Soo King 68 ESD Course Causes of ESD
Inadequate protection, prevention, and verification.
Too many static generators in work area.
Lack of proper training.
Lack of focus. i.e. no steering committee to handle ESD issue. Dr. Lim Soo King 69 ESD Course Causes of ESD
Rapid flow of charge between two objects in contact.
Point of contact.
Surface resistivity.
Work function of materials.
Humidity and temperature.
Insufficient knowledge and poor work procedure. Dr. Lim Soo King 70 ESD Course Factors Influencing ESD Generation
Material Type Conductor - surface resistivity < 105/ . Too rapid discharge. Dissipative – surface resisitivity 106/ and 1012/ . Moderate discharge. Insulator – surface resistivity > 1012/ . Too long discharge.
Integration Scale of IC’s 30 years ago 10-20 µm. Today is sub-micron. Oxide thickness from 1000th Armstrong to less than 100 Armstrong. 90 nm device by Intel has five layers of SiO2 gate only. Dr. Lim Soo King 71 ESD Course Factors Influencing ESD Generation Less electric field is required to damage oxide and active part.
Relative Humidity (RH) High RH means more water. High water content means higher H+ and OH- ions. Increase the surface conductivity. Lesser tendency to lose or acquire electron. Less water content easier to lose or acquire electron. Dr. Lim Soo King 72 ESD Course Factors Influencing ESD Generation Intentionally left blank Dr. Lim Soo King 73 ESD Course ESD Failure Mechanism
How does static electricity damage a circuit?
Effects of ESD damage. Dr. Lim Soo King 74 ESD Course ESD Failure Mechanism
Thermal secondary breakdown
Dielectric breakdown
Gaseous arc discharge/junction spiking.
Bulk breakdown.
Latent and catastrophic failure.
ESD upset – resulting soft bit.
I/O and functional failure.
Joule Heating. T = ASρE πDt . D-thermal diffusivitiy, S-specific heat.
Electrical overstress (EOS). Dr. Lim Soo King 75 ESD Course Identifying of ESD Failure Mechanism
Initial test result – high leakage failure.
Functional test failure.
Pattern test failure.
Deviation of curve tracer results.
Before burn-in, LCD static analysis for hot spot.
After burn-in, high leakage failure at final test results.
Failure analysis to trace the failure site.
High power optical inspection.
Scanning electron microscope analysis. Dr. Lim Soo King 76 ESD Course A Typical Set-Up to Measure Output High Leakage Current IOH
Positive current means possible transistor M3 and M4 have problem.
Negative current means possible transistor M1 and M2 have problem.
Most problem found at the gate, source of p-MOS or drain of n-MOS transistors. Dr. Lim Soo King 77 ESD Course Layout of a Two-input NOR Gate Source Drain Dr. Lim Soo King 78 ESD Course A Typical Set-Up to Measure Output Low Leakage Current IOL Intentionally left blank Dr. Lim Soo King 79 ESD Course Layout of a Two-input AND Gate Drain Source Dr. Lim Soo King 80 ESD Course Curve Tracer Analysis Good 50 40 30 20 10 0 3 2. 5 2 1. 5 1 0. 5 0 -1 -2 -3 -3 .7 -3 .5 -10 Bad -20 -30 Dr. Lim Soo King 81 ESD Course Drain of n-MOSFET damaged by ESD causing leakage to p-substrate region. Dr. Lim Soo King 82 ESD Course Metal 1 fused open and re-flowed/melted Fused open Re-flowed/melted Dr. Lim Soo King 83 ESD Course SEM picture showing oxide damage Dr. Lim Soo King 84 ESD Course SEM picture showing drain/gate damage Dr. Lim Soo King 85 ESD Course SEM picture showing silicon melt Dr. Lim Soo King 86 ESD Course Effects of ESD Damage Intentionally left blank Dr. Lim Soo King 87 ESD Course How does IC’s damaged by static electricity?
Primary factor is transfer of charge between IC’s, which termed as discharge process.
Reduction in capacitance by lifting resulting damage due to increase of voltage.
Charge from operator transfer to IC’s device. Dr. Lim Soo King 88 ESD Course Failure Mechanism due to Transfer of Charge Intentionally left blank Dr. Lim Soo King 89 ESD Course Failure Mechanism due to Lifting
Capacitance is inverse proportional to separation of the capacitor.
If a device on the bench having a few hundred of volt of static charge and is not sufficient to damage the circuit lifting by operator, the reduction in capacitance resulting in increase of static voltage to several thousand voltage can instantly damage the device Dr. Lim Soo King 90 ESD Course ESD Reliability Test
Classification of ESD susceptibility.
Models of ESD reliability test. Dr. Lim Soo King 91 ESD Course Classification of ESD Susceptibility
It depends on the ESD failure model use.
The most susceptible class of product is MOSFET, TFT, GaAsFET, and others.
Schottky diode, Op-Amp, and MOS devices are moderate class.
Resistor chip, low power transistor, SiC devices are least susceptible. Dr. Lim Soo King 92 ESD Course HBM Classification of ESD Susceptibility Class 0 1A 1B 1C 2 3A 3B Voltage Range < 250 V 250 to < 500 V 500 to < 1,000 V 1,000 to < 2,000 V 2,000 to < 4,000 V 4,000 to < 8,000 V ≥ 8,000 V Dr. Lim Soo King 93 ESD Course MM Classification of Product Susceptibility Class Voltage Range M1 < 100 V M2 100 to < 200 V M3 200 < 400 V M4 > or = 400 V Dr. Lim Soo King 94 ESD Course CDM Classification of Product Susceptibility Class C1 C2 C3 C4 C5 C6 C7 Voltage Range < 125 V 125 V to ≤ 250 V 250 V to ≤ 500 V 500 V to ≤ 1,000 V 1,000 V to ≤ 1,500 V 1,500 V to ≤ 2,000 V > 2,000 V Dr. Lim Soo King 95 ESD Course ESD Failure Model Intentionally left blank Dr. Lim Soo King 96 ESD Course Human Body Model
Involve at least two pins.
One is the ground pins. Dr. Lim Soo King 97 ESD Course Machine Model
Involve at least two pins.
One is the ground pins. Dr. Lim Soo King 98 ESD Course Charged Device Model Intentionally left blank Dr. Lim Soo King 99 ESD Course Field Induced Model
Presence of electric field damaging unprotected circuit without discharging. Floating Induced Model
Presence of electric field damaging floating gate. Charged Board Model
Charged board damage is more severe than HBM or CDM due finger inductance and board capacitance. Dr. Lim Soo King 100 ESD Course Ideal RLC Parameters of HBM, MM and CDM ESD Capacitance Resistance Inductance Voltage Model C R I V HBM 100 pF 1.5 kΩ 7500 nH 5 kV MM 200 pF 20 Ω 750 nH 500 V CDM 10 pF 20 Ω 5 nH 500 V Dr. Lim Soo King 101 ESD Course Prevention and Protection Intentionally left blank Dr. Lim Soo King 102 ESD Course Principles of Static Control
Design in immunity.
Eliminate and reduce generation of static electricity.
Dissipate and neutralize.
Prevent and protect from ESD. Dr. Lim Soo King 103 ESD Course Setting-up an ESD Requirement Production Line
Using ESDA S20.20, DOD-HBK-263B, JESD625-A, Mil-std-1686A, and 883 method 3015.7 specifications as the guides.
Convert the requirements into own internal specifications.
Generate audit check sheets and records.
Set-up a ESD Steering Committee
A cross functional team ideally headed by QRA.
Determine the policy and provide recommendation. Dr. Lim Soo King 104 ESD Course Setting-up an ESD Requirement Production Line Intentionally left blank Dr. Lim Soo King 105 ESD Course ESD Safe Workstation
Grounding either hard ground and soft ground.
Conductive flooring/dissipative flooring.
Ground strap.
ESD garment such as finger cot, attire, and shoes.
Dissipative table mat and non-static generating materials.
Localized ionization.
Continuous grounding monitoring system. Dr. Lim Soo King 106 ESD Course Device/PCB Protection Intentionally left blank Dr. Lim Soo King 107 ESD Course
Protect the edge connector of the PCB with conductive shunting bar.
Transport the device/PCB in shielded bag/Faraday cage. Personnel Protection
Always wear a ground strap or ESD footwear before handling device/PCB. Dr. Lim Soo King 108 ESD Course
Always wear ESD protective smock. Warning and Awareness
ESD warning signage at the entrance to ESD work area. Training
Involve all levels of personnel. Dr. Lim Soo King 109 ESD Course
Awareness and re-training.
Constant update of ESD knowledge. Audit
Ensure periodic audit.
Daily check the functionality of ground strap.
Certification and re-certification of personnel for ESD awareness and knowledge. Dr. Lim Soo King 110 ESD Course Typical Facility Areas Requiring ESD Protection
Receiving.
Inspection.
Stores and warehouse.
Assembly.
Test and inspection. Dr. Lim Soo King 111 ESD Course Typical Facility Areas Requiring ESD Protection Intentionally left blank Dr. Lim Soo King 112 ESD Course A Typical ESD Safe Workstation Dr. Lim Soo King 113 ESD Course Good Practices in ESD Work Area
Always ground yourself by wearing a ground strap.
Keep away ESD generator from the device/PCB. e.g. paper, high tension terminal, plastic, and etc.
Always use ESD workstation and wearing ESD attire.
Use shielded box or “low charge generation” tube to store or transport device/PCB. Dr. Lim Soo King 114 ESD Course Good Practices in ESD Work Area Intentionally left blank Dr. Lim Soo King 115 ESD Course ESD Materials Identification and Selection
Material structures and properties.
Criteria of selection.
Material design physics. Dr. Lim Soo King 116 ESD Course Material Properties and Structures
Insulator.
Conduct little electricity.
High surface resistivity. Dr. Lim Soo King 117 ESD Course Resistance and Resistivity of Materials Surface Resistance (ohm) S11.11.1993 Conductive Static Dissipative Insulative Surface Resistivity (Ω Ω/□) ASTM D257 Value 1.0x103 1.0x104 1.0x105 Conductive 1.0x106 1.0x107 1.0x108 1.0x109 1.0x1010 1.0x1011 Static Dissipative 1.0x1012 Insulative Dr. Lim Soo King 118 ESD Course How to Interpret Surface Resistivity?
Surface resistivity (SR) is measured in Ω/□. It is the same irrespective of the square area.
People tend to measure SR using a normal resistance meter and probe, which is wrong.
SR should be measured using mega-ohm meter and square contact as provided in ASTM D257 and S11.11. Dr. Lim Soo King 119 ESD Course How to Interpret Surface Resistivity?
If a 10 Ω resistance has a square surface. We say the resistance is 10 Ω and SR is 10 Ω/□.
If two similar resistors are connected in series then the resistance is 20 Ω and the SR is not 20 Ω/□.
If two of these two resistors are connected in parallel then the effective resistance is 10 Ω and SR is 10 Ω/□.
This example illustrates that SR is same irrespective of the size of the square. Dr. Lim Soo King 120 ESD Course Criteria for Selection of ESD Materials Intentionally left blank Dr. Lim Soo King 121 ESD Course Material Design Physics
Turning insulator into having antistatic properties.
Antistatic surfactant such as ethoxylated amines or ethoxylated ester mixed with polymer. Commonly known as pink poly.
Conductive filler such as carbon black, carbon fiber, stainless-steel fiber, and etc mixed with polymer.
Inherently Dissipative polymer alloys IDP. Dr. Lim Soo King 122 ESD Course Material Design Physics Antistatic surfactant Carbon-filled polymer Coating of carbon black Inherently Dissipative poly alloy Dr. Lim Soo King 123 ESD Course Material Design Physics Intentionally left blank Surface resistivity comparison for various techniques Dr. Lim Soo King 124 ESD Course ESD Materials, Monitoring/Measurement Tools and Awareness Label
ESD materials.
Monitoring tools.
Prevention materials.
Protection materials. Dr. Lim Soo King 125 ESD Course Common ESD Control Materials in ESD Work Area
Personal grounding.
Protective clothing/smock/shoes.
Dissipative table mat.
ESD chair.
Conductive box/bag.
Conductive foam.
Antistatic tube.
Antistatic flooring. Dr. Lim Soo King 126 ESD Course Common ESD Control/Monitoring Materials in ESD Work Area Intentionally left blank Dr. Lim Soo King 127 ESD Course Ground Strap Physical Appearance Internal construction with Human body model 2.0 kV ESD voltage generates 1.3 A current without ground strap. 2.0 kV ESD voltage generates 2.0 mA current with ground strap. Discharge time – 150 µs without ground strap. Discharge time – 100 ms with ground strap. Dr. Lim Soo King 128 ESD Course ESD Smock Cotton type is ideal because it is relatively neutral Dr. Lim Soo King 129 ESD Course Static Dissipative Bag
Low static generator (antistatic) “pink poly” polyethylene type, which is low-end ESD bag.
Carbonate non-transparent conductive bag.
Static shielding bag (Faraday shield) has a aluminum coating deposited on polyester film outer layer and inner polyethylene layer.
Metal in has high resistance and metal out has lower resistance.
Moisture Vapor Barrier shielding bag has 10X thickness of normal bag. Dr. Lim Soo King 130 ESD Course Static Dissipative Bag – A Typical Construction Intentionally left blank Dr. Lim Soo King 131 ESD Course Conductive Bag Dr. Lim Soo King 132 ESD Course Conductive Foam and Antistatic Tube Dr. Lim Soo King 133 ESD Course Conductive Box – Carbon filled polymer Dr. Lim Soo King 134 ESD Course Antistatic Flooring Dr. Lim Soo King 135 ESD Course Static Dissipative Mat
Volumetric type-Homogeneous Non constant discharge time. Difficult to ground. Cheap. Ideal for service not for production.
Conductive type – Non-Homogeneous Constant discharge time. Easy ground. Costly. Ideal for production. Dr. Lim Soo King 136 ESD Course Antistatic Mat Dr. Lim Soo King 137 ESD Course ESD Symbols Ground Point Symbol ESD Susceptibility Symbol Dr. Lim Soo King ESD Protective Symbol 138 ESD Course ESD Chair The ESD Chair is designed
conductive materials.
hooded static-free casters.
static-free fabric material.
comfort
ergonomic. Dr. Lim Soo King 139 ESD Course Ionizer Intentionally left blank Dr. Lim Soo King 140 ESD Course Ionizer – An ac Type Dr. Lim Soo King 141 ESD Course Ionizer – A dc Type Corona discharge depends on curvature of the electrode. 100 µm radius – 2 kV, 500 µm radius – 4 kV and 1000 µm radius – 6 kV. Dr. Lim Soo King 142 ESD Course Shoes/Shoes Strap
Use human sweat as the conducting medium. Dr. Lim Soo King 143 ESD Course ESD Monitor Equipment Static Field Meter Megaohm meter Dr. Lim Soo King 144 ESD Course ESD Monitor Equipment – Charge Plate
Discharge time measurement.
Ion balance check. Dr. Lim Soo King 145 ESD Course ESD Monitor Equipment – Faraday Cup Measurement of charge Dr. Lim Soo King 146 ESD Course Circuit Design Protection
Approach.
Methods employed for design protection and prevention. Dr. Lim Soo King 147 ESD Course Approach Intentionally left blank Dr. Lim Soo King 148 ESD Course Electrical Strength of Semiconductor Material
Field strength of silicon dioxide is 109 volts/meter. A device of oxide thickness 500 Armstrong, it needs only 50 volts to destroy the oxide.
The typical diode avalanche voltage is 5 V to 20 volts.
Junction breakdown for JFET and MOSFET is typically 20 V. Dr. Lim Soo King 149 ESD Course Circuit Design Protection
Resistor Limiting current and provide voltage drop.
Diode Low resistance large current handling capability to bypass charge.
Thickness field oxide device (TFO). Dr. Lim Soo King 150 ESD Course Circuit Design Protection Intentionally left blank Dr. Lim Soo King 151 ESD Course Resistor - Diode Circuit
Resistor R – 1.5 Ω shall cause voltage drop.
Positive ESD bypassed through diode D1.
Negative ESD bypassed through diode D2. Dr. Lim Soo King 152 ESD Course Resistor - Diode Circuit Dr. Lim Soo King 153 ESD Course n-Type Diffusion Resistor Dr. Lim Soo King 154 ESD Course Thickness Field Oxide Device

Operate like a lateral npn transistor. The drain space determines the maximum current carrying capacity. Dr. Lim Soo King 155 ESD Course n-MOS Pull Down Model It may cause secondary breakdown Dr. Lim Soo King 156 ESD Course p-MOSFET Pull-Up Model Intentionally left blank Dr. Lim Soo King 157 ESD Course Triggering Graph of Lateral npn Transistor
Point 1, avalanche begins.
Point 2, snapback occurs. The lateral npn transistor is selfBiased mode.
Point 3, heating up of drainsubstrate causes secondary breakdown exceed junction temperature. Dr. Lim Soo King 158 ESD Course Silicon Control Rectifier- Low Voltage Triggered Type Dr. Lim Soo King 159 ESD Course Model of Silicon Control Rectifier Dr. Lim Soo King 160 ESD Course Triggering Graph of Silicon Control Rectifier Intentionally left blank Dr. Lim Soo King 161 ESD Course Generic Protection Circuit - NMOS Clamp Dr. Lim Soo King 162 ESD Course Specifications and Standards
ESD/EOS standard.
Compliance.
Own specifications. Dr. Lim Soo King 163 ESD Course ESD Compliance Specifications
DOD-HBK-263 B, JESD625-A, Mil-std1686A, and 883 E method 3015.7 are sufficient.
ESDA S20.20 is sufficient to industrial standard. The spec. covers many areas of control.
Design immunity, ESD susceptibility, and classification. Dr. Lim Soo King 164 ESD Course ESD Compliance Specifications
Control and prevention.
Qualification and acceptance of new equipment and materials.
Testing circuit including ESD classification tests.
Auditing.
Training.
Quality system. Dr. Lim Soo King 165 ESD Course Assessment Test Dr. Lim Soo King 166 ESD Course Discussion Dr. Lim Soo King 167 ESD Course Thank You Dr. Lim Soo King 168