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关键词： Crack propagation model   Power cycling   IGBT   Low temperature gradients   Plastic strain   Lifetime  

摘要： In this paper, a new model for wirebond degradation during power cycling in IGBT power module is proposed. This model is based on experimental crack propagation analyses and on a plastic strain empirical law. For the experiments, two power cycling tests in switching mode under high voltage were carried out respectively with junction temperature swings of ?T-j = 30? and 40? at a minimal temperature of T-j,T-min = 55?. The DUTs and the test conditions were chosen so that only degradations of chip top-side interconnections could occur. The onstate voltage (V-CE) was measured online during the tests as an indicator of wire and metallization degradations, moreover, the samples were removed at different aging stages. The removed samples were cross-sectioned in order to observe the crack propagation evolution with cycling. Concerning the plastic strain law, we used results from literature giving the evolution of the plastic strain variation (?(epl)) with bond-wire contact crack growth. As results, this new lifetime prediction model based on a modified Paris's law for aluminium wire bonds fatigue of IGBTs shows a good fitting of the test results and is it can be used to predict the lifetime under other load conditions. Finally, the lifetime of tested IGBT modules are estimated and used to verify the effectiveness of the proposed model.

关键词： Index Terms-Cryogenic   Discrete wavelet transform   Hybrid dc breaker   IGBT   Machine learning   protection   SMES   SFCL   SVM  

摘要： To reduce emissions from the aviation industry and meet the targets set by different countries, research has been focused on investigating all-electric aircraft. To make this vision practical, superconducting machines are expected to power the propellers, as they are half the size and a third the weight of conventional machines. The main purpose of this paper is to do a higher-level study of a reliable holistic protection system for all-electric aircraft;that can reduce heat leakage and be able to detect faults reliably. Thus, three main protection systems were investigated;1) cryogenic voltage source converter superconducting magnetic energy storage system (VSC-SMES), 2) cryogenic dc breaker integrated with superconducting fault current limiter (SFCL), and 3) machine learning algorithm for fault detection. By immersing the protection system at cryogenic temperature, the paper has shown that passive leakage can be eliminated, and thus more energy can be saved for the fuel cell. The paper has also demonstrated that using machine learning for the SFCL-dc-breaker system can consistently eliminate faults and protect the system.

关键词： Health monitoring   Power cycle degradation   IGBT module  

摘要： The bond wire lift-off is the one of main failures for insulated gate bipolar transistors (IGBT) power modules. The wire lift-off increases parasitic inductance LeE in the module and the gate voltage Vge waveform is modulated by LeE & BULL;dIe/dt. Therefore, the Vge waveform has the potential for an indicator of condition monitoring. The Digital gate control (DGC) can control switching behavior precisely for low-loss and low-noise switching. It is also effective for sensitivity enhancement of Vge waveform changed by the wire lift-off. This paper reports how the DGC 2-step vector control (2-sVC) can improve the wire lift-off failure detection sensitivity by Vge waveform. The experiment results showed that the Vge spike was generated by LeE & BULL;dIe/dt at the turn-off switching and the spike generation timing depended on the wire number. The DGC obtained the larger timing-shift & UDelta;twire and the amplitude & UDelta;Vge-surge than those at the conventional gate control. In addition, the best vector condition improved the trade-off between turn-off loss and collector voltage overshoot compared with the conventional gate control. From these results, the DGC is effective to enhance the sensitivity of bond wire lift-off detection by Vge waveform maintaining the best switching performance.

关键词： IGBT power module   microchannel   cooling plate   micropump  

摘要： In high-integration electronic components, the insulated-gate bipolar transistor (IGBT) power module has a high working temperature, which requires reasonable thermal analysis and a cooling process to improve the reliability of the IGBT module. This paper presents an investigation into the heat dissipation of the integrated microchannel cooling plate in the silicon carbide IGBT power module and reports the impact of the BL series micropump on the efficiency of the cooling plate. The IGBT power module was first simplified as an equivalent-mass block with a mass of 62.64 g, a volume of 15.27 cm(3), a density of 4.10 g/cm(3), and a specific heat capacity of 512.53 J/(kg center dot K), through an equivalent method. Then, the thermal performance of the microchannel cooling plate with a main channel and a secondary channel was analyzed and the design of experiment (DOE) method was used to provide three factors and three levels of orthogonal simulation experiments. The three factors included microchannel width, number of secondary inlets, and inlet diameter. The results show that the microchannel cooling plate significantly reduces the temperature of IGBT chips and, as the microchannel width, number of secondary inlets, and inlet diameter increase, the junction temperature of chips gradually decreases. The optimal structure of the cooling plate is a microchannel width of 0.58 mm, 13 secondary inlets, and an inlet diameter of 3.8 mm, and the chip-junction temperature of this structure is decreased from 677 degrees C to 77.7 degrees C. In addition, the BL series micropump was connected to the inlet of the cooling plate and the thermal performance of the microchannel cooling plate with a micropump was analyzed. The micropump increases the frictional resistance of fluid flow, resulting in an increase in chip-junction temperature to 110 degrees C. This work demonstrates the impact of micropumps on the heat dissipation of cooling plates and provides a foundation for the design o

关键词： IGBT   Technology Computer Aided Design (TCAD)   Numerical model   Parameter extraction   Convolutional neural network (CNN)  

摘要： The electrical behavior of the IGBTs is the key factors to the application of IGBTs. Technology Computer Aided Design (TCAD) is one of the most effective methods for characterizing of electrical behavior of IGBT. However, the great difficulties in extracting the model's parameters hinder its widely applications. In the present work, a high-precision TCAD model for FS-Trench IGBT was established and verified by experiments. Firstly, the parameters necessary for TCAD models were analyzed in theoretical and experimental. The key process parameters need to be determined in a value range table. A Convolutional Neural Network (CNN) was proposed and trained to form a relationship from characteristic curves to key process parameters. Subsequently, the numerical model's parameters were established by combining the trained CNN model with experimental data. Finally, the TCAD model was established and the simulations of IGBTs were carried out and verified by experiments. Results demonstrate that the proposed TCAD model is well consistent with experiments with a Root Mean Square Error (RMSE) of about 3.7 %. This work may provide a feasible method to obtain highly precise numerical models of power semiconductor devices. It may also promote the application of Artificial Intelligence in the device modeling and optimization design.

关键词： Insulated gate bipolar transistors (IGBT)  

摘要： Les transistors de puissance comme les IGBT et les MOSFET sont une source d’interférences électromagnétiques (EMI) pendant les commutations en raison des variations rapides de tension/courant. L’augmentation de la durée des commutations peut réduire la production des EMI mais augmente les pertes. Plusieurs techniques de commande rapprochée pour réduire ces EMI ont été proposées dans la littérature. Dans ce travail, une commande basée sur le contrôle d’un profil de courant de grille, rendu possible par de nouveaux drivers disponibles sur le marché, est proposé. Pour cela, on s’appuie sur la caractéristique du transistor de tension grille-source en fonction de la charge injectée dans la grille. Afin de démontrer la performance de cette méthode, elle est évaluée par simulation SPICE à l’aide d’un facteur de mérite permettant de la comparer quantitativement à une technique de référence dénommée CATS (Commande autour de la Tension de Seuil). Copyright © 2023, The Authors. All rights reserved.

关键词： Design  

摘要： This paper aims to clarify the effect of asymmetric gate inductance Lg and emitter inductance Le inside power modules with two parallel-connected IGBTs on switching characteristics when a three-step digital gate driver is employed. Five types of IGBT modules with different Lg and Le were fabricated to implement double pulse tests by conventional gate driving and digital gate driving with three-step vectors. Under the conventional gate driving, the asymmetric Le introduced an imbalanced current during on-stage, and the asymmetric Lg introduced gate voltage spike Vg_spike and an imbalanced current during the turn-off interval. Large Lg introduced large Vg_spike. From the miller plateau in the turn-off, the current started to concentrate on the IGBT whose Lg is small. In the turn-on interval, the asymmetric Le made current share in two IGBTs become imbalanced, and the occurred large Vg_spike is positively corresponding to the difference of emitter current Ie flowing through two IGBTs. Under digital gate driving, it was found that the tradeoff between switching loss and voltage/current overshoots can be improved. And, the difference of Eoff between two IGBT chips, which results from asymmetric Le mainly, could be decreased more than that in conventional gate driving. In the turn-on interval, the large Vg_spike can be suppressed by a small vector number at the second step, and the difference of turn-on loss Eon could be also decreased. According to the above switching characteristics, the design considerations of power modules with parallel-connected IGBTs were proposed as the digital gate driver is applied. © 2023, The Authors. All rights reserved.

关键词： Insulated gate bipolar transistors (IGBT)  

摘要： In this paper, the floating P-pillar SJ-IGBT with floating P-region and hole path separated by dummy trench is proposed to have extended switching performance with balanced low Eoff compared with conventional floating P-pillar SJ-IGBT and some improved structures. In the on-state, the hole path is depleted by dummy trench with a positive gate potential and the hole path is pinched off in combination with the existing floating P-region to enhance the carrier storage effect and reduce the Von. In the turn-off transient, as the gate potential on the dummy trench is removed, the hole path automatically opens and some of the holes accumulated in the drift region flow to the emitter through this path, enabling the proposed FPHP-SJ-IGBT to turn off quickly. The TCAD simulation results reveal that at the same Von of 1.24V, the Eoff of FPHP SJ-IGBT is 1.21mJ/cm2, which is reduced by 84.7%, 72.6% and 20.9%, respectively, compared with *** P-pillar SJ-IGBT, improved structures SJ-IGBT-A and SJ-IGBT-B. © 2023, The Authors. All rights reserved.

关键词： Insulated gate bipolar transistors (IGBT)  

摘要： Operation mechanisms of the N-type Carrier-storage (N-CS) layer and Super-junction (SJ) pillar in Carrier-storage Super-junction Insulated Gate Bipolar Transistor (CS-SJBT) are clearly investigated in paper. It is pointed out that, under the effect of N-CS layer, Von of CS-SJBT is no more constrained by pillar doping and it is reduced to comparable with conventional Carrier-storage N-drift IGBT (CS-NDBT). Structural evolutions from CS-NDBT to CS-SJBT and their effects are illustrated to reveal mechanism of SJ pillar. It is shown that, the slightly lower Von of CS-SJBT than CS-NDBT is owing to their equivalent current output ability and thinner pillar region, and the substantially reduced switching loss attributes to the different electric field morphology in SJ pillar, which are supported by experimental contrasts. After these, the conventional advantage of SJ in reducing on-state loss of unipolar SJ-MOSFETs is diverted/extended to switching loss reduction ability in bipolar CS-SJBTs. © 2023, The Authors. All rights reserved.

关键词： CFD   electronic cooling   heat sink   IGBT   pumping power   s-CO2  

摘要： High-pressure drops characteristic of microchannel heat sinks (MCHS) is an issue that needs to be addressed to reduce the size of heat-removing devices in compact electronic devices. Supercritical carbon dioxide (s-CO2) is a suitable candidate being proposed as an alternative coolant to enhance the cooling of the microchannel heat sink (MCHS), with high heat flux, due to its favorable thermophysical properties near its critical point. In this study, numerical simulations are conducted to evaluate the thermal and hydraulic performance of a channel for a designed heat sink with s-CO2 (at constant P = 8 MPa) and compare it with conventional liquid coolant (water). The effect of coolants mass flow rate ((m) over dot), channel aspect ratio (AR), and inlet temperatures on the thermal and hydraulic performance of one channel is studied by varying (m) over dot from 0.004 to 0.03 kg/s and AR from 0.33 to 10. The results show that, for the same aspect ratio, same geometry, and constant heat flux, s-CO2 offers a higher overall heat transfer coefficient (32%) with a lower friction factor (pumping power) compared with the water at the same inlet temperature (T = 32 degrees C). The results of pumping power comparison between two coolants reveal that for CO2 in supercritical conditions (P = 8 MPa, T = 32 degrees C), the consumed power varies by change of the aspect ratio, which is 1.85 times lower than water for AR = 0.33 and is 3.6 times higher for AR = 10. However, in the subcooled state, the reverse effect of the aspect ratio is seen.