ESD

May 31, 2018 | Author: Cruise_Ice | Category: Electrostatic Discharge, Electrostatics, Mosfet, Electrical Breakdown, Electrical Resistivity And Conductivity
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ESD CourseDr. 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 Movement and discharge time.ESD Course Outline of the Course Materials and Environment Material properties. Lim Soo King 4 . Temperature and relative humidity. Dr. Gas discharge. Chargeability. Induction. Lim Soo King 5 . Factors influencing static charge generation.ESD Course Outline of the Course Mechanism of ESD Electrification. Dr. Triboelectric series. Causes of ESD . Dr.ESD Course Outline of the Course ESD Failure Mechanism How does static electricity damage a circuit? Effects of ESD damage. Lim Soo King 6 . Models of ESD reliability test.ESD Course Outline of the Course ESD Reliability Test Classification of ESD susceptibility. Lim Soo King 7 . Dr. ESD Course Outline of the Course Prevention and Protection Principles of Static Control. Setting up ESD requirement production line. Good practice in ESD work area. Lim Soo King 8 . Electrostatic protected area. Dr. Handling and storage of ESD sensitive parts. Audit. ESD Course Outline of the Course ESD Materials Identification and Selection Material structures and properties. Material design physics. Lim Soo King 9 . Dr. Criteria of selection. ESD Course Outline of the Course ESD Materials Monitoring/Measurement Tools and Awareness Label ESD materials. Prevention materials. Monitoring tools. Protection materials. Lim Soo King 10 . Dr. Dr. Methods employed for design protection and prevention.ESD Course Outline of the Course Circuit Design Protection Approach. Lim Soo King 11 . Lim Soo King 12 . Discussion Dr. Assessment Twenty questions.ESD Course Outline of the Course Case Study Self audit. ESD Course Introduction and Overviews History. Field Return Rate. Evolution ad Interpretation. World Semiconductor Production. ESD Failure Rate. Lim Soo King 13 . What is ESD? Dr. National Technology Roadmap for Semiconductor Picture illustrating ESD Failure. Dr. paper industry.ESD Course History In 1400’s ESD procedure was installed to prevent electrostatic discharge ignition of black gun power in Europe and Caribbean. it was used to prevent fire and during drying process in paper mill. microelectronics industry. In1860. and others. Lim Soo King 14 . ESD control is employed in many areas such as ship yard. assembly plant. In modern world. ESD Course ESD Failure Rate Descriptions Component Manufacturer Subcontractor Contractors User Min.14 % 27 – 33 % Dr. Loss 4% 3% 2% 5% Max. Lim Soo King 15 . Loss 16 – 22 % 9 – 15 % 8. Loss 97 % 70 % 35 % 70 % Est. Avg. 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 . Lim Soo King 17 .ESD Course Field Return Failure Mode Dr. Lim Soo King 18 .035 0.6 664 M 0.13) (0.5 44 M 0. 99 0.18) 1.9 2.2 109 M 0.5 0.050 (0.6 M 02 05 08 11 14 0.10 0.065) (0.9 18 M 1.8 269 M Dr.6 0.13 0.5 6.8 1.0 1.18 (0.07 0.ESD Course National Technology Roadmap for Semiconductor Year Channel length (µm) Equivalent oxide thickness (µm) Transistor density (cm2) Red is actual channel.045) 1.5 1. ESD Course Pictures of ESD Failure Dr. Lim Soo King 19 ESD Course Picture of ESD Failure Junction spiking Dr. Lim Soo King Dielectric Breakdown 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 . Lim Soo King 23 .ESD Course Picture of ESD Failure Base-emitter region Dr. Lim Soo King Metallization Burn 24 .ESD Course Picture of ESD Failure Secondary breakdown Dr. Lim Soo King 25 .ESD Course Evolution and Interpretation Intentionally left blank Dr. Dr. Lim Soo King 26 .ESD Course What is ESD? ESD is defined as electrostatic discharge. It is a process of electron transfer between materials. Lim Soo King 27 . It is a material that conducts very small amount of electricity. Material loses electron has net positive charge. the electron equilibrium state remains for a long time.ESD Course What is ESD? Insulator is the main contributor of ESD. The most common way of generating static electricity is friction (contact and separate). Material acquires electron has net negative charge. Dr. Once the material loses or acquires electron. ESD Course What is ESD? Induction by EM interference causing polarization of charge to other material at the polarized end. Dr. When the charge material comes in contact with another material. When two materials come in contact and separate. static electricity will be generated. Example of such source is high tension terminal. Lim Soo King 28 . transfer of electron would occur resulting damage to the material. ESD Course Balance of Charge Dr. Lim Soo King 29 . Lim Soo King 30 .ESD Course Transfer of Charge After Separation Intentionally left blank Dr. Lim Soo King 31 .ESD Course Transfer of Charge After Separation Dr. ESD Course Generation of Static Charge by Separation Intentionally left blank Dr. Lim Soo King 32 . Lim Soo King 33 .ESD Course Generation of Static Charge by Separation Dr. Temperature and relative humidity. Lim Soo King 34 . Dr. Movement and discharge time.ESD Course Materials and Environment Material properties. No band-gap. Lim Soo King 35 . Semiconductor Conduct small amount of electricity.ESD Course Material Properties Conductor Conduct good electricity. Dr. Low resistance. High resistance Large band-gap Dr.ESD Course Material Properties Moderate resistance. Narrow band-gap. Lim Soo King 36 . Insulator Conduct very small amount or no electricity. ESD Course Band-gap of Insulator Dr. Lim Soo King 37 . Lim Soo King 38 .ESD Course Band-gap of Conductor Intentionally left blank Dr. 0 µs 1010 Ω 106 Ω 920 µs 1011 Ω 92 s 107 Ω 9. Lim Soo King 39 .5 hrs 92 ms 920 ms Dr.6 ms 1013 Ω 2.ESD Course Discharge Time Using Human Body Model Resistance Time (ms) Resistance Time (ms) 102 Ω 92 ns 109 Ω 103 Ω 2.2 ms 1012 Ω 920 s 108 Ω 76. ESD Course Movement time of Typical Operation Intentionally left blank Dr. Lim Soo King 40 . ESD Course Temperature and Relative Humidity High temperature. Dr. Lim Soo King 41 . Increase surface conductivity. High relative humidity. more dissociation of water molecule. Reduce surface resistivity. less charge generation. high thermionic emission. Lim Soo King 35.000 20.000 7.500 42 .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.000 6.200 1.000 1.ESD Course Typical Electrostatic Voltage at Different RH Means of Static Generation 10 .000 12.000 18.500 250 100 600 1. ESD Course Surface Resistivity versus RH at 25C Intentionally left blank Dr. Lim Soo King 43 . Chargeability. Causes of ESD . Factors influencing static charge generation. Dr. Gas discharge. Triboelectric series. Induction. Lim Soo King 44 .ESD Course Mechanism of ESD Electrification. Lim Soo King 45 .ESD Course Electrification Materials in Contact + A + + + + + B Helmholtz Interface (10 nm) Dr. ESD Course Intentionally left blank Dr. Lim Soo King 46 . ESD Course Materials Separation + A + + + + Point of Neutralization + B Dr. Lim Soo King 47 . temperature and humidity. Neutralization tends to happen due to gas discharge. surface resistivity of material. Capacitance decreased many folds.ESD Course The interface gap increased many folds. Neutralization depends on rate of separation. Gas discharge if electric field is greater than 3 MV/m. Electric field is extremely high. Dr. Lim Soo King 48 . Potential difference between positively and negatively charged layers increased tremendously. 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. Lim Soo King 53 . redistribution of positive charge Dr. Lim Soo King 54 .ESD Course Electrostatic Induction Positive charge remains on conductor Dr. ESD Course Electrostatic Discharge Intentionally left blank Dr. Lim Soo King 55 . Small surface high electric field. Lim Soo King 56 .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. 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. Dr.ESD Course Type of Electrostatic Discharge Corona discharge. Flash lightning. Spark discharge. Lim Soo King 57 . Lim Soo King 58 .ESD Course Corona Discharge Charged object Electric field Corona needle point A Dr. Positive and negative ions generated. the electric field builds up. As the pointed needle is closed to charged conductor. This principle is used to eliminate static charge.ESD Course Corona Discharge Presence of electric field. Micro-ammeter will register current. Dr. Lim Soo King 59 . Color visual light can be observed. Corona discharge can be occurred with applied high potential to pointed needle. Ionization (corona) occurs when reaches critical field (3 MV/m). Lim Soo King 60 .ESD Course Demonstration of Corona Discharge Corona discharge Dr. ESD Course Spark Discharge Discharge between flat metallic electrodes. Capacitor Metallic plate Dr. Lim Soo King 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 Lim Soo King 64 .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 65 .ESD Course Trioelectric Series continues Wood Hard rubber Brass Silver Sealing wax Polyester Polyethylene PVC Silicon Negative (acceptor) .Teflon Dr. ESD Course Trioelectric Series Material with high relative permittivity tends to lose electron easier than material with low relative permittivity. Dr. Lim Soo King 66 . High surface conductivity. less charge. ESD Course Triboelectric -Relative Permittivity Intentionally left blank Dr. Lim Soo King 67 . brushes. Plastic. ungrounded solder iron. heat gun. painted or varnished surface. and etc. Dr. Lim Soo King 68 . wraps. envelope. sand blasting. temperature chamber.ESD Course Typical Source of Static Generator in MFG Area Work surface Floor Clothes Chair Packaging and handling Assembly Cleaning Test Repair Waxed. Common vinyl or plastic. bubble pack. bag. Spray cleaner. Synthetic personal garments. trays. Sealed concrete or sheeting. boxes. Fiber glass. Finished wood. no steering committee to handle ESD issue.ESD Course Causes of ESD Inadequate protection. Lack of focus. Lim Soo King 69 . Too many static generators in work area. prevention. i.e. Lack of proper training. Dr. and verification. Humidity and temperature.ESD Course Causes of ESD Rapid flow of charge between two objects in contact. Insufficient knowledge and poor work procedure. Lim Soo King 70 . Surface resistivity. Dr. Work function of materials. Point of contact. Lim Soo King 71 Integration Scale of IC’s . Insulator – surface resistivity > 1012/ . 90 nm device by Intel has five layers of SiO2 gate only. Too rapid discharge. Dr. Today is sub-micron. Too long discharge. Moderate discharge. Dissipative – surface resisitivity 106/ and 1012/ .ESD Course Factors Influencing ESD Generation Material Type Conductor .surface resistivity < 105/ . 30 years ago 10-20 µm. Oxide thickness from 1000th Armstrong to less than 100 Armstrong. High water content means higher H+ and OH. Increase the surface conductivity. Dr. Less water content easier to lose or acquire electron. Relative Humidity (RH) High RH means more water.ions. Lim Soo King 72 . Lesser tendency to lose or acquire electron.ESD Course Factors Influencing ESD Generation Less electric field is required to damage oxide and active part. ESD Course Factors Influencing ESD Generation Intentionally left blank Dr. Lim Soo King 73 . Lim Soo King 74 .ESD Course ESD Failure Mechanism How does static electricity damage a circuit? Effects of ESD damage. Dr. Dr. I/O and functional failure. Joule Heating. Latent and catastrophic failure. S-specific heat.ESD Course ESD Failure Mechanism Thermal secondary breakdown Dielectric breakdown Gaseous arc discharge/junction spiking. Electrical overstress (EOS). ESD upset – resulting soft bit. D-thermal diffusivitiy. Bulk breakdown. T = ASρE πDt . Lim Soo King 75 . Before burn-in.ESD Course Identifying of ESD Failure Mechanism Initial test result – high leakage failure. High power optical inspection. After burn-in. Pattern test failure. Scanning electron microscope analysis. Failure analysis to trace the failure site. high leakage failure at final test results. LCD static analysis for hot spot. Dr. Lim Soo King 76 . Deviation of curve tracer results. Functional test failure. Lim Soo King 77 . source of p-MOS or drain of n-MOS transistors. Most problem found at the gate. Negative current means possible transistor M1 and M2 have problem. Dr.ESD Course A Typical Set-Up to Measure Output High Leakage Current IOH Positive current means possible transistor M3 and M4 have problem. ESD Course Layout of a Two-input NOR Gate Source Drain Dr. Lim Soo King 78 . Lim Soo King 79 .ESD Course A Typical Set-Up to Measure Output Low Leakage Current IOL Intentionally left blank Dr. ESD Course Layout of a Two-input AND Gate Source Drain Dr. Lim Soo King 80 . 7 -3 . 5 -3 . Lim Soo King 2 3 81 .5 2. 5 Bad Good -10 -20 -30 0 1 -3 -2 -1 Dr.ESD Course Curve Tracer Analysis 50 40 30 20 10 0 0. 5 1. Dr.ESD Course Drain of n-MOSFET damaged by ESD causing leakage to p-substrate region. Lim Soo King 82 . Lim Soo King Re-flowed/melted 83 .ESD Course Metal 1 fused open and re-flowed/melted Fused open Dr. ESD Course SEM picture showing oxide damage Dr. Lim Soo King 84 . Lim Soo King 85 .ESD Course SEM picture showing drain/gate damage Dr. Lim Soo King 86 .ESD Course SEM picture showing silicon melt Dr. Lim Soo King 87 .ESD Course Effects of ESD Damage Intentionally left blank Dr. Charge from operator transfer to IC’s device.ESD Course How does IC’s damaged by static electricity? Primary factor is transfer of charge between IC’s. Lim Soo King 88 . Reduction in capacitance by lifting resulting damage due to increase of voltage. which termed as discharge process. Dr. 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. the reduction in capacitance resulting in increase of static voltage to several thousand voltage can instantly damage the device Dr. Lim Soo King 90 . 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. Models of ESD reliability test. Lim Soo King 91 . Dr.ESD Course ESD Reliability Test Classification of ESD susceptibility. GaAsFET. TFT. Resistor chip. Dr. Schottky diode. and others. Lim Soo King 92 . Op-Amp. The most susceptible class of product is MOSFET. SiC devices are least susceptible. and MOS devices are moderate class. low power transistor.ESD Course Classification of ESD Susceptibility It depends on the ESD failure model use. 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 to < 4. Lim Soo King 93 .000 V 1.000 to < 8.000 V Dr.000 V 2.000 to < 2.000 V 4.000 V ≥ 8. ESD Course MM Classification of Product Susceptibility Class M1 M2 M3 M4 Voltage Range < 100 V 100 to < 200 V 200 < 400 V > or = 400 V Dr. Lim Soo King 94 . 500 V to ≤ 2.000 V 1. Lim Soo King 95 .500 V 1.000 V to ≤ 1.000 V Dr.000 V > 2.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. Lim Soo King 96 .ESD Course ESD Failure Model Intentionally left blank Dr. One is the ground pins.ESD Course Human Body Model Involve at least two 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 . Dr. Charged Board Model Charged board damage is more severe than HBM or CDM due finger inductance and board capacitance. Lim Soo King 100 .ESD Course Field Induced Model Presence of electric field damaging unprotected circuit without discharging. Floating Induced Model Presence of electric field damaging floating gate. Lim Soo King 101 . MM and CDM ESD Capacitance Resistance Inductance Voltage Model C R I V HBM MM CDM 100 pF 200 pF 10 pF 1.ESD Course Ideal RLC Parameters of HBM.5 kΩ 20 Ω 20 Ω 7500 nH 750 nH 5 nH 5 kV 500 V 500 V Dr. ESD Course Prevention and Protection Intentionally left blank Dr. Lim Soo King 102 . Dissipate and neutralize. Lim Soo King 103 . Prevent and protect from ESD.ESD Course Principles of Static Control Design in immunity. Eliminate and reduce generation of static electricity. Dr. 7 specifications as the guides.20. and 883 method 3015. Generate audit check sheets and records.ESD Course Setting-up an ESD Requirement Production Line Using ESDA S20. Set-up a ESD Steering Committee A cross functional team ideally headed by QRA. Mil-std-1686A. JESD625-A. Determine the policy and provide recommendation. Lim Soo King 104 . Convert the requirements into own internal specifications. Dr. DOD-HBK-263B. Lim Soo King 105 .ESD Course Setting-up an ESD Requirement Production Line Intentionally left blank Dr. Lim Soo King 106 .ESD Course ESD Safe Workstation Grounding either hard ground and soft ground. Dr. Conductive flooring/dissipative flooring. Continuous grounding monitoring system. attire. and shoes. Localized ionization. Dissipative table mat and non-static generating materials. Ground strap. ESD garment such as finger cot. ESD Course Device/PCB Protection Intentionally left blank Dr. Lim Soo King 107 . Dr. Personnel Protection Always wear a ground strap or ESD footwear before handling device/PCB. Lim Soo King 108 .ESD Course Protect the edge connector of the PCB with conductive shunting bar. Transport the device/PCB in shielded bag/Faraday cage. Dr. Warning and Awareness ESD warning signage at the entrance to ESD work area.ESD Course Always wear ESD protective smock. Training Involve all levels of personnel. Lim Soo King 109 . Audit Ensure periodic audit.ESD Course Awareness and re-training. Certification and re-certification of personnel for ESD awareness and knowledge. Daily check the functionality of ground strap. Lim Soo King 110 . Constant update of ESD knowledge. Dr. Dr. Assembly. Stores and warehouse. Lim Soo King 111 . Inspection. Test and inspection.ESD Course Typical Facility Areas Requiring ESD Protection Receiving. Lim Soo King 112 .ESD Course Typical Facility Areas Requiring ESD Protection Intentionally left blank Dr. Lim Soo King 113 .ESD Course A Typical ESD Safe Workstation Dr. Keep away ESD generator from the device/PCB. Lim Soo King 114 . Always use ESD workstation and wearing ESD attire. e. plastic.ESD Course Good Practices in ESD Work Area Always ground yourself by wearing a ground strap. Use shielded box or “low charge generation” tube to store or transport device/PCB. and etc. Dr. paper. high tension terminal.g. ESD Course Good Practices in ESD Work Area Intentionally left blank Dr. Lim Soo King 115 . Criteria of selection. Dr.ESD Course ESD Materials Identification and Selection Material structures and properties. Material design physics. Lim Soo King 116 . ESD Course Material Properties and Structures Insulator. Lim Soo King 117 . High surface resistivity. Conduct little electricity. Dr. 0x103 1.0x106 1.0x1012 Surface Resistivity (Ω/□) ASTM D257 Conductive Static Dissipative Insulative Insulative 118 Dr.0x105 1.1993 Conductive Static Dissipative Value 1.ESD Course Resistance and Resistivity of Materials Surface Resistance (ohm) S11.0x1011 1.0x109 1.0x104 1.0x108 1.0x1010 1. Lim Soo King .0x107 1.11. People tend to measure SR using a normal resistance meter and probe. which is wrong. It is the same irrespective of the square area. Lim Soo King 119 .ESD Course How to Interpret Surface Resistivity? Surface resistivity (SR) is measured in Ω/□.11. SR should be measured using mega-ohm meter and square contact as provided in ASTM D257 and S11. Dr. ESD Course How to Interpret Surface Resistivity? If a 10 Ω resistance has a square surface. If two similar resistors are connected in series then the resistance is 20 Ω and the SR is not 20 Ω/□. We say the resistance is 10 Ω and SR is 10 Ω/□. Dr. This example illustrates that SR is same irrespective of the size of the square. Lim Soo King 120 . If two of these two resistors are connected in parallel then the effective resistance is 10 Ω and SR is 10 Ω/□. Lim Soo King 121 .ESD Course Criteria for Selection of ESD Materials Intentionally left blank Dr. Dr.ESD Course Material Design Physics Turning insulator into having antistatic properties. and etc mixed with polymer. Lim Soo King 122 . carbon fiber. Conductive filler such as carbon black. Inherently Dissipative polymer alloys IDP. Antistatic surfactant such as ethoxylated amines or ethoxylated ester mixed with polymer. stainless-steel fiber. Commonly known as pink poly. Lim Soo King 123 .ESD Course Material Design Physics Antistatic surfactant Carbon-filled polymer Coating of carbon black Inherently Dissipative poly alloy Dr. Lim Soo King 124 .ESD Course Material Design Physics Intentionally left blank Surface resistivity comparison for various techniques Dr. Monitoring/Measurement Tools and Awareness Label ESD materials. Prevention materials. Protection materials. Lim Soo King 125 . Dr. Monitoring tools.ESD Course ESD Materials. Dr. Dissipative table mat.ESD Course Common ESD Control Materials in ESD Work Area Personal grounding. Antistatic flooring. Conductive box/bag. ESD chair. Antistatic tube. Protective clothing/smock/shoes. Lim Soo King 126 . Conductive foam. Lim Soo King 127 .ESD Course Common ESD Control/Monitoring Materials in ESD Work Area Intentionally left blank Dr. 2.0 kV ESD voltage generates 2. Dr. Discharge time – 150 µs without ground strap.3 A current without ground strap.0 mA current with ground strap. Discharge time – 100 ms with ground strap.ESD Course Ground Strap Physical Appearance Internal construction with Human body model 2.0 kV ESD voltage generates 1. Lim Soo King 128 . Lim Soo King 129 .ESD Course ESD Smock Cotton type is ideal because it is relatively neutral Dr. Metal in has high resistance and metal out has lower resistance.ESD Course Static Dissipative Bag Low static generator (antistatic) “pink poly” polyethylene type. Dr. Moisture Vapor Barrier shielding bag has 10X thickness of normal bag. Lim Soo King 130 . Static shielding bag (Faraday shield) has a aluminum coating deposited on polyester film outer layer and inner polyethylene layer. Carbonate non-transparent conductive bag. which is low-end ESD bag. Lim Soo King 131 .ESD Course Static Dissipative Bag – A Typical Construction Intentionally left blank Dr. ESD Course Conductive Bag Dr. Lim Soo King 132 . ESD Course Conductive Foam and Antistatic Tube Dr. Lim Soo King 133 . Lim Soo King 134 .ESD Course Conductive Box – Carbon filled polymer Dr. Lim Soo King 135 .ESD Course Antistatic Flooring Dr. Costly. Cheap. Ideal for service not for production. Difficult to ground. Easy ground. Dr.ESD Course Static Dissipative Mat Volumetric type-Homogeneous Non constant discharge time. Ideal for production. Conductive type – Non-Homogeneous Constant discharge time. Lim Soo King 136 . ESD Course Antistatic Mat Dr. Lim Soo King 137 . Lim Soo King 138 .ESD Course ESD Symbols Ground Point Symbol ESD Susceptibility Symbol ESD Protective Symbol Dr. Dr. hooded static-free casters. comfort ergonomic. Lim Soo King 139 . static-free fabric material.ESD Course ESD Chair The ESD Chair is designed conductive materials. Lim Soo King 140 .ESD Course Ionizer Intentionally left blank Dr. ESD Course Ionizer – An ac Type Dr. Lim Soo King 141 . Dr. 500 µm radius – 4 kV and 1000 µm radius – 6 kV. Lim Soo King 142 .ESD Course Ionizer – A dc Type Corona discharge depends on curvature of the electrode. 100 µm radius – 2 kV. ESD Course Shoes/Shoes Strap Use human sweat as the conducting medium. Dr. Lim Soo King 143 . Lim Soo King Megaohm meter 144 .ESD Course ESD Monitor Equipment Static Field Meter Dr. ESD Course ESD Monitor Equipment – Charge Plate Discharge time measurement. Lim Soo King 145 . Dr. Ion balance check. Lim Soo King 146 .ESD Course ESD Monitor Equipment – Faraday Cup Measurement of charge Dr. Lim Soo King 147 . Methods employed for design protection and prevention. Dr.ESD Course Circuit Design Protection Approach. ESD Course Approach Intentionally left blank Dr. Lim Soo King 148 . Junction breakdown for JFET and MOSFET is typically 20 V. The typical diode avalanche voltage is 5 V to 20 volts. A device of oxide thickness 500 Armstrong. Dr. Lim Soo King 149 .ESD Course Electrical Strength of Semiconductor Material Field strength of silicon dioxide is 109 volts/meter. it needs only 50 volts to destroy the oxide. Dr. Lim Soo King 150 . Diode Low resistance large current handling capability to bypass charge. Thickness field oxide device (TFO).ESD Course Circuit Design Protection Resistor Limiting current and provide voltage drop. ESD Course Circuit Design Protection Intentionally left blank Dr. Lim Soo King 151 . Dr.ESD Course Resistor .Diode Circuit Resistor R – 1. Lim Soo King 152 .5 Ω shall cause voltage drop. Negative ESD bypassed through diode D2. Positive ESD bypassed through diode D1. Diode Circuit Dr. Lim Soo King 153 .ESD Course Resistor . ESD Course n-Type Diffusion Resistor Dr. Lim Soo King 154 . The drain space determines the maximum current carrying capacity.ESD Course Thickness Field Oxide Device Operate like a lateral npn transistor. Lim Soo King 155 . Dr. Lim Soo King 156 .ESD Course n-MOS Pull Down Model It may cause secondary breakdown Dr. ESD Course p-MOSFET Pull-Up Model Intentionally left blank Dr. Lim Soo King 157 . Point 2. Lim Soo King 158 .ESD Course Triggering Graph of Lateral npn Transistor Point 1. heating up of drainsubstrate causes secondary breakdown exceed junction temperature. Point 3. Dr. avalanche begins. snapback occurs. The lateral npn transistor is selfBiased mode. Lim Soo King 159 .ESD Course Silicon Control Rectifier.Low Voltage Triggered Type Dr. Lim Soo King 160 .ESD Course Model of Silicon Control Rectifier Dr. 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 susceptibility. covers many areas of control.ESD Course ESD Compliance Specifications DOD-HBK-263 B. ESDA S20. Dr.20 is sufficient to industrial standard. The spec. JESD625-A. and 883 E method 3015. Lim Soo King 164 . and classification.7 are sufficient. Design immunity. Mil-std1686A. Dr. Auditing. Testing circuit including ESD classification tests. Quality system.ESD Course ESD Compliance Specifications Control and prevention. Lim Soo King 165 . Qualification and acceptance of new equipment and materials. Training. ESD Course Assessment Test Dr. Lim Soo King 166 . Lim Soo King 167 .ESD Course Discussion Dr. ESD Course Thank You Dr. Lim Soo King 168 .


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