Electrostatic Discharge Generator Research Articles

Electromagnetic Fields Radiated by Electrostatic Discharges: A Review of the Available Approaches

Electrostatic discharge (ESD) is a physical phenomenon that may destroy electronic components due to its high discharge current that may reach a few amperes in just a few ns. However, another major aspect of ESD is the related high-frequency electromagnetic (E/M) fields radiated by the ESD event. The electronic equipment that is affected by the ESD phenomenon is additionally affected by the induced voltages caused by these E/M fields. This is the reason that the current version of the IEC 61000-4-2 on ESD has a special reference to these fields and the measurement setup. Starting with the classical formulation of these fields, this paper reviews the most popular techniques for calculating the ESD electromagnetic fields while also emphasizing the best methods for minimizing computational effort. There is also a separate section for the measurement techniques that have been applied in research works, whose outcomes could be implemented in the next revision of the IEC 61000-4-2. It is extremely important for the next revision to include these measurement setups and the E/M field sensors because the ESD generators should comply with certain values related to the E/M fields they produce.

Human Metal ESD: Design of a Full-Wave Model and an Improved Compact Generator

A full-size, full-wave human body model has been designed. Compared with a real human-metal electrostatic discharge (ESD), similar fields and currents are obtained from the numerical model. A resistive surface sheet is used in microwave studio to control the currents on the air-filled body. Its performance is verified by comparing it to the currents and fields from the real human ESD. A subcircuit models the time-dependent resistance of the spark using the well-known Rompe–Weizel spark resistance model. Real human metal ESD does not reveal the double hump shape as shown in the IEC standard. To create a generator that reproduces the real human metal ESD current waveform, a compact ESD generator was designed, which is based on matching the impedance of real human metal mode ESD with the impedance of the compact ESD generator. Furthermore, a circuit-based simulator is presented. It is based on a PCB implementation of the equivalent circuit of the human metal ESD.

Accurate and Efficient Computation of System-Level ESD Noise Waveforms in ISO 10605 Standard Using Decomposition Method and Split-Domain Approach

In this article, an accurate and efficient computational method of system-level electrostatic discharge (ESD) noise waveforms in a field-coupled ESD test of the ISO 10605 standard using a 3-D full-wave solver is proposed. To apply efficient computational methods to the ESD test simulation, the split-domain approach and decomposition method are first individually validated with a simple structure. Next, a method simultaneously using the decomposition method and split-domain approach is proposed and validated with the separately given field source data. Using the proposed method with the measured electromagnetic fields radiated from an ESD generator, the ESD noise waveforms in the ISO 10605 field-coupled ESD test are accurately and efficiently computed by considering not only the ESD current coupling but also the radiated coupling from the ESD generator.

Modular Measurement System for System-Efficient ESD Design on System and Component Level

For the electrostatic discharge (ESD) characterization of components or systems, complex measurements of voltages and currents are required. The measurements are then used to characterize, model, and verify simulations. Both physical damage and upset are expected; however, performing these experiments on evaluation boards is often not suitable since the required current and voltage ports are not integrated. Furthermore, repeatedly reworking the integrated circuit (IC) will quickly destroy the evaluation board. A new modular experimental platform was therefore developed to flexibly perform such complex measurements. The modularity greatly simplifies measurements and allows for replacement of damaged components. The system consists of injection modules, such as universal serial bus (USB) and sub miniature version A (SMA) connections, excitation modules, such as a transmission line pulse and an ESD generator, modules for voltage and current measurements for characterization of transient voltage suppressor diodes and ICs, modules carrying passive channels, and active modules for the ICs being characterized. As active parts, which serve as device under tests, a set of USB 3.1 repeaters, controller area network (CAN) bus, and radio frequency (RF) front-end ICs are added to individual modules. The modules themselves, their characterization, and usage are explained in this article.

ESD-Event Detector for ESD Control Applications in Semiconductor Manufacturing Factories

An electrostatic discharge (ESD)-event detector has been designed and fabricated in a single chip to detect and alarm the ESD events in semiconductor or integrated circuit (IC) manufacturing environments. The experiment measured results showed that the peak-to-peak voltage of the detected signal during an ESD event has a strong correlation with its ESD-stress voltage level. <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">The proposed ESD-event detector can determine a</b> detected <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">signal to be an ESD pulse if its signal amplitude is higher than the settable threshold and its duration time is under 500 ns.</b> The ESD-event detector circuit, including a <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">450 MHz</b> logarithmic amplifier, a comparator, and a time discriminator, has been implemented in a single chip with a total silicon area of only 693 × 563 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ</i> <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\mathbf{m}}^2$</tex-math></inline-formula> and fabricated by 0.18- <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ</i> m CMOS process. <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">The detector can detect high-frequency transient signals up to 450 MHz, which has been successfully verified in the field tests by detecting the signals generated from the ESD generators, the human-body model tester, and the field-induced charged-device model tester.</b> The proposed ESD-event detector can efficiently perform the real-time ESD monitoring applications in the IC and semiconductor manufacturing factories.

Circuit-Aided Dummy Design for Human Body-Worn ESD Application

Electrostatic discharge (ESD) is considered for different postures of the body and for different positions of a device under test (DUT). These scenarios lead to large variations in peak discharge currents, and a traditional commercial ESD generator cannot test these satisfactorily. Instead of using actual humans, a full-size dummy has been designed for different body-worn ESD test scenarios, its discharge currents and fields are verified by comparing the measurement results with those taken from volunteers. A wearable DUT on the wrist, elbow, and waist is taken into consideration to compare the characteristics of the dummy to those of the real human body. Furthermore, a circuit model is proposed to aid in understanding the dummy design and the different body-worn scenarios. Finally, the effect of an external connection with different waist positions is analyzed and discussed in a more complex application scenario.

Effects of nematic liquid crystal doped with multi-walled carbon nanotube on electro-optic properties and electrostatic discharge immunity of liquid crystal display device

ABSTRACT Electrostatic discharge is a vexing problem in liquid crystal display device, which can cause abnormal display. Conventional solutions for liquid crystal doped with antistatic agent usually introduce additional impurity ions and increases the power consumption of liquid crystal display device. In this study, multi-walled carbon nanotube doped liquid crystal cells without obvious clusters are successfully fabricated. Comparing the electro-optic properties of undoped and doped cells, it is verified that doping does not negatively affect the liquid crystal cells with E7 host by measuring basic parameters such as relative permittivity, threshold voltage and response time. The liquid crystal cells are then tested using an electrostatic discharge generator to simulate the human-machine air discharge that occurs during actual operation. The immunity of the doped versus undoped cells is quantitatively compared in terms of the duration of so-called image sticking, it is found that the electrostatic discharge immunity of cell has a significant relationship with electrical conductivity. In addition, the relationship between the conductivity and relaxation time of image sticking is obtained by theory. It is determined that doping carbon nanotubes into E7 can effectively improve the electrostatic discharge immunity of liquid crystal display device without negatively affecting practical application.

Circuit Modeling and Simulation of the ESD Generator for Various Tested Equipment According to the IEC 61000-4-2

The existing IEC Standard for Electrostatic Discharge (ESD) contains a general and simplified circuit for the generator that produces ESD discharges, without entering into details. The present work tries to fill this gap and proposes a circuit which will generate the ESD current in the limits that the current Standard defines. Two circuit models are examined through simulations with SPICE software, with the one to be the most suitable. This circuit model is also examined for various loads that simulate the Equipment under Test (EUT) and useful conclusions derive up to what type and size of equipment can be safely tested by ESD generators so that the test results are reliable.

Machine Learning Techniques for the Prediction of the Magnetic and Electric Field of Electrostatic Discharges

The magnetic and electric fields of electrostatic discharges are assessed using the Naïve Bayes algorithm, a machine learning technique. Laboratory data from electrostatic discharge generators were used for the implementation of this algorithm. The applied machine learning algorithm can be used to predict the radiated field knowing the discharge current. The results of the Naïve Bayes algorithm are compared to a previous software tool derived by Artificial Neural Networks, proving its better outcome. The Naïve Bayes algorithm has excellent performance on most classification tasks, despite its simplicity, and usually is more accurate than many sophisticated methods. The proposed algorithm can be used by laboratories that conduct electrostatic discharge tests on electronic equipment. It will be a useful software tool, since they will be able to predict the radiating electromagnetic field by simply measuring the discharge current from the electrostatic discharge generators.

Investigations Into Unintended ESD Generator Artifacts: Prepulse and Postpulse

An electrostatic discharge (ESD) generator may create pre- and postpulses in addition to the main pulse. These artifacts can cause additional device under test (DUT) failures. The origin and magnitude of these pulses were investigated in four commercial generators using measurements and simulation. Two types of unwanted pulses were identified. One is caused by the reignition of the spark, and the other relates to the relay contacting for charging the main capacitor. These pulses cause strong high-frequency signals, partially surpassing the radio frequency content of the main pulse. The spectrum of the pre- and postpulses varies greatly between different generators. These differences and the fact that some DUTs may react to the pre- or postpulse instead of the main pulse lead to repeatability problems between test sites. The other artifact that has been investigated is the leakage current in contact discharge mode. The charge accumulated on the gun tip by the leakage current can contribute to a short (few nanoseconds) fast-rising pulse (<500 ps) that occurs the moment the tip is contacted, thus, before the main pulse in contact mode.

Analysis of the ESD Reconstruction Methodology Based on Current Probe Measurements and Frequency Response Compensation for Different ESD Generators and Severity Test Levels

System-level electrostatic discharge testing according to IEC 61000-4-2 has been the main standardized electrostatic discharge immunity testing procedure for the last few decades. The correlation between a failed test result and the injected electrostatic discharge current waveform characteristics, as well as the reduced reproducibility of the standard methodology, have always concerned product manufacturers and test engineers. In an effort to accurately reconstruct the electrostatic discharge current during immunity testing, researchers are focusing more and more on the usability of current probes in capturing the injected current in “real time”. In this article, the results of a proposed methodology, based on current probe measurements and a frequency response compensation method, published in recent bibliography, for different test levels and electrostatic discharge generators are presented, aiming to highlight the advantages and disadvantages of the method, investigate its universal applicability, and introduce points of future work toward the current reconstruction during system-level electrostatic discharge testing effort.

Field source extraction of an ESD generator and its application to system-level ESD analysis in a solid-state storage system

System-level electrostatic discharge (ESD) noise due to electromagnetic fields radiating from an ESD generator were measured and analyzed in a solid-state drive (SSD) storage system. The field sources of an ESD generator were efficiently modeled from the measured tangential magnetic fields in front of a ESD generator. The extracted field sources were incorporated into a full-wave solver, and the fields inside the disk-array enclosure (DAE) were simulated and validated by comparing to measured fields. The field source models of the ESD generator were then also utilized to predict transient ESD-induced noise voltages in a simplified SSD. Finally, the coupling mechanism and the effects of the DAE geometry were investigated.

Field-Circuit Co-Simulation Method for Electrostatic Discharge Investigation in Electronic Products

Electrostatic discharge (ESD) plays an important role in the hard or soft failure of electronic products due to its high voltage, strong electric field, instantaneous high current, and a wide spectrum electromagnetic radiation. A field-circuit co-simulation method combining circuit elements and full-wave 3D model is applied to investigate ESD effects on a system including ESD generator, electronic device and IC chips on PCB, which can obtain both the electromagnetic field and the voltage/current information. The signal transmitting can be monitored under ESD-event when different discharge voltage polarity and protective enclosures are applied. Moreover, transient voltage suppressors can be appended to the field-circuit co-simulation model and their effects to ESD protection are investigated. The research on the field-circuit co-simulation of electronic products puts forward a more practical simulation method for electrostatic discharge.

A Specific Relationship between Spark Lengths and Discharge Current Peaks via Ambient Temperature and Absolute Humidity for Air Discharges from Electrostatic Discharge Generator

A Specific Relationship between Spark Lengths and Discharge Current Peaks via Ambient Temperature and Absolute Humidity for Air Discharges from Electrostatic Discharge Generator

Design of an Artificial Dummy for Human Metal Model ESD

Electrostatic discharge (ESD) generators do not match each other, nor do the currents and fields from the discharge of a human via a piece of metal match those from ESD generators. A more realistic characterization of the field performance of a device under test (DUT) can be achieved using human subjects. To avoid using actual humans, while still achieving similar results, a full-size dummy has been designed. Its performance is verified by comparing it to currents and fields from human ESD and ESD generators.

Influence of Absolute Humidity and Saturation Deficit on Air Discharge Currents from Electrostatic Discharge Generator with Three Different Approach Speeds

Influence of Absolute Humidity and Saturation Deficit on Air Discharge Currents from Electrostatic Discharge Generator with Three Different Approach Speeds

Characterization of ESD shielding materials with novel test methods

Electrostatic discharge (ESD) shielding effectiveness of materials used to protect ESD sensitive devices was evaluated with a coaxial electrode and ESD generator. Attenuation of a continuous low power signal and a high power transient was measured. Electromagnetic far field shielding does not necessarily address ESD protection performance. High impedance on a discharge path reduces energy coupling efficiently. Therefore the prevention of conductive and capacitive coupling is the key factor for designing protective packaging for transportation of ESD sensitive devices. Due to the effect of breakdown field strength, low power signals shall not be used alone to assess ESD shielding characteristics. A coaxial electrode and an ESD generator was found a useful combination for the evaluation of ESD shielding effectiveness. As a final outcome, adequate ESD protection can be achieved even without the far field shielding, depending on application.

Full-Wave Simulation of System-Level Disruption During Secondary ESD Events in a Smartphone

To demonstrate the electromagnetic full-wave simulation of a secondary electrostatic discharge (ESD), an ESD generator is modeled in three dimensions (3D) and in contact mode discharging to a non-grounded, metallic ear-mesh of a smartphone. The nonlinear Rompe–Weizel SPICE model computes the arc resistance of the secondary discharge between ungrounded metal and a grounded enclosure. The SPICE model is solved using a circuit simulator, and the 3-D model is solved using the transmission-line matrix time-domain numerical method. Transient cosimulation is a new technique that is used to solve both circuit and 3-D models at the same time. The simulation predicts the coupling from ESD to a victim trace in the smartphone. Measurements performed at several stages validate the simulation results. Using this novel methodology, the user can simulate the secondary discharge in products to predict ESD damage and disruption on a system level.

Effect of Different Load Impedances on ESD Generators and ESD Generator SPICE Models

The electrostatic discharge (ESD) generator calibration described in IEC 61000-4-2 (2008) only specifies contact mode discharge waveforms for the discharge-into-ground scenario. However, the actual device under test input impedance often differs from a short. To study the effect of different load impedances, a test method for ESD generator discharge under different load impedances is proposed. The method only slightly modifies the present calibration setup. The data show that the peak current variation between different brands of ESD generators for nonshorted load impedances is within the tolerance range given by the standard for the peak current. On the other hand, when performing system-efficient ESD design simulations, the load impedance seen by the ESD generator models is also different than a short. Therefore, the discharge current of a variety of ESD generator models is simulated with different load impedances and compared with ESD generator measurement results, which allows the selection of a suitable ESD generator model.

Step-Response-Based Calibration Method for ESD Generators in the Air-Discharge Mode

The current IEC 61000-4-2 (2008) standard does not provide calibration specifications for electrostatic discharge (ESD) generators in the air-discharge mode. This is largely due to the well-known fact of poor repeatability in air-discharge measurements. This complicates identifying an acceptable tolerance range of a reference waveform for air discharge. The variability of the discharge waveforms is caused by variations in the spark length. A novel air-discharge calibration method is proposed, which avoids sparking. The method is based on measuring the step response of an ESD generator in the air-discharge mode using a mercury-wetted relay. Possible nonlinear effects are identified during the contact-mode ESD simulator calibration at higher voltages; thus, in combination, an air-discharge calibration method is provided. This letter explains the method and shows excellent repeatability.