ESD
Short Description
VLSI...
Description
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
View more...
Comments
