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关键词： Insulated gate bipolar transistors   Wires   Mathematical models   Stress   Couplings   Thermal expansion   Thermal stresses   Bond wire failure   electro-thermal-mechanical   insulated gate bipolar transistor (IGBT)   multiphysics coupling model  

摘要： Due to the coefficients of thermal expansion (CTE) mismatch between various materials, the bond wire of insulated gate bipolar transistor (IGBT) module is prone to heel-cracking or lift-off failure under power cycling, which will affect the performance of the module. In this article, an electro-thermal-mechanical multiphysics coupling model was constructed for IGBT module, and the accuracy of the model was validated by steady-state conduction experiment. Based on the simulation model, the characteristics of IGBT module were further simulated under the normal state conduction operation, and the results showed that the stress of the middle bond position on a single bond wire is higher. Then, the research on the influence of heel-cracking and lift-off failure of the bond wire was carried out. The simulation results showed that the heel-cracking failure of the bond wire will cause obvious effect, in which the increase stress can be as high as 77.4 MPa. When the bond wires are detached one by one until five bond wires were lifted off, the temperature in the remaining bond wires increases by 48.7 C-degrees, which has a significant impact on the module. The research in this article can provide the basis for improving the reliability of IGBT module and the optimization of module package design.

关键词： Insulated gate bipolar transistors   Aging   Wires   Bonding   Magnetic flux density   Resistance   Voltage measurement   Bonding wire lift-off   condition monitoring   magnetic flux density   multi-chips parallel IGBT (insulated gate bipolar transistor)   solder fatigue  

摘要： IGBT modules are widely used in various fields of power electronics, and their reliability is important for power systems. Multi-chips parallel IGBT modules face more challenges in condition monitoring and health assessment due to their complex spatial structure, uneven current distribution, and uneven temperature distribution, resulting in uneven aging. Focusing on this problem, based on the multi-physics field finite element simulation technology, the degradation law of the electrothermal and magnetic characteristic parameters during the aging failure process of the multi-chips parallel IGBT module is studied, and the magnetic flux density is used as the aging status monitoring parameter. A health status evaluation model is established for the bonding wire lift-off and solder layer aging failure modes, which is used to realize multi-chips parallel IGBT module failure type identification and quantitatively evaluate for the health status and aging chip positioning. Then, the accuracy of the health assessment model is verified by experiments, and the condition monitoring method does not require changing or touching the internal circuits of the modules. Finally, an aging failure mode based on the change of the sum of the magnetic flux density is proposed to realize the judgment of the aging failure mode and the quantitative evaluation of the health status.

关键词： Silicon carbide   Stacking fault   Bipolar degradation   IGBT   Power device  

摘要： Silicon carbide (SiC) power devices are heading towards high power and high voltage, where 4H-SiC bipolar devices play a key role due to low on -resistance and ultra -high blocking voltage. However, stacking faults (SFs) can result in forward voltage drifts and increased reverse leakage currents in bipolar devices. Moreover, SFs expand easily from basal plane dislocation (BPD) under current stress, severely damaging the device reliability. In this review, the properties and characterization methods of SFs are presented. The formation and expansion mechanisms of SFs and the approaches to suppress SFs expansion are addressed. In particular, the challenge of SFs suppression in insulated gate bipolar transistors (IGBTs) is also discussed. Finally, this review proposes some directions for futher SFs research, which could provide insights into controlling SFs in 4H-SiC epilayers and IGBTs.

关键词： Si-IGBT   Radiation effect   Energy deposition  

摘要： Silicon-insulated gate bipolar transistors (Si-IGBTs) are widely used for power control. In this study, we measured the energy deposited inside a commercial device with neutrons irradiation from 252Cf. We irradiated the device from the sealing and heat sink sides to evaluate the directional characteristics. A radiation simulation analysis was performed to understand the measurement results. The experiment and simulation showed that energy deposition in the device occurs through elastic scattering of neutrons and nuclear reactions. In particular, protons were generated by elastic scattering in the sealing material when the device was irradiated from the sealing side. Thus, the effect of neutrons on commercial Si-IGBTs is due to not only reactions inside the device but also secondary particles from the sealing material. When irradiated with high-energy neutrons, the knocked-out protons from sealing possibly cause single-event burnout (SEB). Therefore, the probability of SEB may depend on the direction of neutron incidence.

关键词： Ignition systems   dynamic modeling   free response   frequency response   MOSFET   IGBT  

摘要： This paper envisages studying the features of a conventional inductive ignition system along with its MOSFET and IGBT-based transistorized modifications. The influence of mechanical contact breaker dynamics and ignition coil characteristics on the current and voltage waveforms of the primary and secondary circuits of these studied ignition systems are mathematically and experimentally exposed. The investigation is considered necessary prior to attempting subsequent modeling and diagnostics procedures on the current-voltage performance characteristics of conventional and transistorized ignition systems. The work has demanded the development of an experimental setup based on a basic modifiable ignition system mockup and an instrumentation system to measure and analyze the voltage-current parameters of inductive ignition systems. The paper describes the design details of such instrumentation system, presents mechanical and electrical models for contact breaker and ignition circuits, then simulated to obtain base free-run response waveforms and electrical continuity behavior of the contact. A test of frequency response of the ignition coil provided additional input to the model. An experimental test of continuity of the contact, in agreement with its model, shed light on the actual excitation of the primary coil. The work comments on a sample of the registered current and voltage waveforms in primary and secondary coil windings of the ignition system at atmospheric conditions. Comparisons of waveforms and energy for mechanical contact, MOSFET and IGBT switches are made to establish them as a reference for future tests.

关键词： Current sharing among IGBT cells   dynamic avalanche   press-pack insulated gate bipolar transistor (PP IGBT) chip   pressure distribution  

摘要： Within a press-pack insulated gate bipolar transistor (PP IGBT) submodule, the components are packaged by external clamping force. This external clamping force significantly affects the chip's dynamic avalanche and further degrades its turn-off capability, which needs to be investigated. In this article, it is found for the first time that the pressure distribution is the key factor for the IGBT chip's dynamic avalanche during a single turn-off period. Simulation results indicate that the maximum pressure difference on the chip surface rises by 1.5 times when the clamping force increases from 1 to 2.5 kN. During turn-off, that pressure distribution leads to a 21.21% increase in the maximum current density inside the single chip, which strengthens the dynamic avalanche. To verify this mechanism, the turn-off waveforms of a single chip under different forces are then measured and compared in detail. Meanwhile, these conclusions regarding the pressure distribution effect are applicable to the single chip inside the multichip device in practical applications. Moreover, suggestions for the packaging design and practical operation are put forward to improve the PP IGBT device's turn-off capability effectively.

关键词： aging monitoring   IGBT   solder layer   transfer function   void fraction  

摘要： This paper proposes a method based on transfer function to monitor the solder layer void damage in IGBT modules. Firstly, the thermal resistance of each layer structure of IGBT module and the Cauer model is analyzed. Secondly, the process of obtaining the parameters of Cauer model by transfer function is analyzed. Finally, the thermal resistance of the IGBT module under different void fractions of the solder layer is measured by experiments, which obtains the relationship between the thermal resistance difference and the void fractions. In addition, this method is compared with the monitoring method by IEC standard, which verifies the accuracy and feasibility of this method.

关键词： Insulated gate bipolar transistors   Solid modeling   Observers   Temperature sensors   Monitoring   Finite element analysis   Thermal analysis  

摘要： Dynamic temperature monitoring at critical locations of IGBT modules is a key means to improve the reliability of high-power converters. However, most existing thermal model-based methods suffer from temperature estimation errors due to model parameter variations and loss calculation errors. To address this problem, based on the reduced-order thermal model, an $H_{\infty}$ observer-based robust 3-D thermal monitoring method for IGBT modules is proposed in this paper. Through the optimized design of the observer feedback gain, the thermal model and real-time temperature information are effectively combined, which reduces the temperature estimation error in the worst case. Thus, the proposed method is more robust to model parameter uncertainty and loss error than the conventional temperature observers. Experiment validations of the proposed $H_{\infty}$ observer and conventional observers are provided. The results demonstrate that the proposed observer achieves the highest temperature estimation accuracy under various system uncertainties, making it an effective solution for reliable online thermal monitoring of IGBT modules over the whole life cycle.

摘要： Nowadays, Power Electronics is paying greater attention to the rapid advancement of power semiconductor devices. This paper examines the quantitative analysis of the Direct Matrix Converter using both MOSFET and IGBT for high efficiency converters. As a result, the IGBT has a substantially lower switching loss than the MOSFET. Additionally, switching loss for MOSFETs will significantly increase at high operating temperatures, whereas switching loss for IGBTs hardly varies with temperature. In this paper, by comparing switching power loss, temperature, volume, weight requirements, power quality, efficiency, and static characteristics, the performance of IGBT and MOSFET is assessed. It has been concluded through a comparison of the device parameters that IGBTs outperforms MOSFETs in terms of smaller loss, greater efficiency, and smaller size.