Electronic devices using semiconductors such as insulated-gate bipolar transistors, metal–oxide–semiconductor field-effect transistors, and diodes are extensively used in electrical traction applications such as locomotive, elevators, subways, and cars. The long-term reliability of such power modules is then highly demanded, and their main reliability criterion is their power cycling capability. Thus, a power cycling test is the most important reliability test for power modules. This test consists in periodically applying a current to a device mounted onto a heat sink. This leads to power loss in the entire module and results in a rise in the semiconductor temperature. In this paper, the different kinds of semiconductors and power modules used for traction applications are described. Experimental and simulation methods employed for power cycling tests are presented. Modules' weak points and fatigue processes are pointed out. Then, a detailed statistical review of publications from 1994 to 2015 dealing with power cycling is presented. This review gives a clear overview of all studies dealing with power cycling that were carried out until now. It reveals the principal trends in power electronic devices and highlights the main reliability issues for which an important lack of knowledge remains.

Power Cycling Reliability of Power Module: A Survey

This paper introduces a novel three-level voltage-source converter (VSC) as an alternative to known three-level topologies, including the conventional neutral-point-clamped converter (NPCC), many T-type VSCs, and active NPCC. It is shown that, operating in the low converter dc-link voltage range, this new solution not only can achieve higher efficiency than many typical three-level structures but also can overcome their drawback of asymmetrical semiconductor loss distribution for some operating conditions. Therefore, a remarkable increase of the converter output power capability and/or system reliability can be accomplished. The switching states and commutations of the converter, named here as hybrid NPCC (H-NPCC), are analyzed, and a loss-balancing scheme is introduced. Five- and seven-level H-NPCC topologies with loss-balancing features are also presented. Finally, a semiconductor-area-based comparison is used to further evaluate many three-level VSC systems. Interestingly, the total chip area of the proposed H-NPCC is already the lowest for low switching frequencies.

The New High-Efficiency Hybrid Neutral-Point-Clamped Converter

This paper presents the reliability analysis of a push-pull converter intended for connection to a 125-W photovoltaic (PV) panel. Four prototypes of the converter were built and tested, using transistors with different ratings. Failure rates were calculated using the MIL HDBK 217 and the IEC TR 62380 procedures. In the latter case, the prediction was performed taking into account an annual mission profile obtained from the intended installation site, in an area with desert climate temperatures. Failure rate results obtained with MIL HDBK 217 show small differences among the converters, the best performance obtained from the prototype with the lowest on-resistance. Results obtained with IEC TR 62380 indicate that thermal cycles have a significant effect in reliability performance, and should be considered carefully, because PV systems often see large temperature variations. With both procedures, the failure rate contributions from magnetic devices were higher than expected.

Effect of the Mission Profile on the Reliability of a Power Converter Aimed at Photovoltaic Applications—A Case Study

Thermal–mechanical behavior of the bonding wire for a power module subjected to the power cycling test

A Voltage Source Converter (VSC) (10) with Neutral-Point-Clamped (NPC) topology with one or more phases, comprises an intermediate DC circuit having at least a first and a second capacitance connected in series between a positive terminal and a negative terminal, providing a central tap terminal between both capacitances, and at least one sub-circuit for generating one phase of an alternating voltage, each sub-circuit comprising an AC terminal for supplying a pulsed voltage; a circuit arrangement of the form of a conventional NPC converter, with a first series connection of at least two switches between said AC terminal and said positive terminal, a second series connection of at least two switches between said AC terminal said negative terminal, and switchable connections from said central tap terminal to the centers of both two-switch series connections; and additional first and second auxiliary switches assigned to said two-switch series connections.

Voltage source converter (VSC) with neutral-point-clamped (NPC) topology and method for operating such voltage source converter

For power devices, the reliability of thermal fatigue induced by power cycling has been prioritized as an important concern. Because, the power device like the converter system is the key in vehicle applications. So, high reliability is demanded by reduction in the size and high power capacity. Therefore shortening reliability evaluation is demanded using finite element method (FEM). Since power cycling produces non-uniform temperature distribution in the device, coupled thermal-mechanical analysis is required to evaluate thermal fatigue mechanism. The thermal expansion difference between a package and a substrate causes thermal fatigue. Many studies on thermal fatigue in electronics devices have been reported but temperature is often assumed to be uniform under thermal cycling environment. In this study, thermal fatigue of solder joints on power device was evaluated. Joule heating produces temperature distribution, which affects the behavior of thermal fatigue. The FEM was used to evaluate temperature distribution induced by joule heating. Higher temperature appears below the bonded wire because the electric current flow through the bonding wire. Coupled thermal-mechanical analysis was also performed to evaluate the inelastic strain distribution. The damage of each element can be calculated from equivalent inelastic strain range and crack propagation was simulated by deleting damaged elements step by step. The crack initiates below the bonded wire and propagates concentrically under power cycling. There is the difference from environmental thermal cycling where the crack initiates at the edge of solder. And power cycle switching frequency was compared. It was clarified that power cycle fatigue life depends on power cycle switching frequency. As a result, the failure mechanism of thermal fatigue by joule heating was clarified. Therefore the evaluation method could propose best experimental conditions in power cycle experiment.

Power cycle fatigue reliability evaluation for power device using coupled electrical-thermal-mechanical analysis

This paper presents a simulation method to evaluate the thermal fatigue life of a power module. A coupled electrical-thermal analysis was performed to obtain the nonuniform temperature distribution of electric current. Then, a thermomechanical analysis was carried out based on the temperature distribution from the electrical-thermal analysis. Since crack propagation can change the route of heat transfer, a crack path simulation technique was used to investigate the fracture behavior of the power module. The crack initiates in the solder joint below the Al bonding wire of the insulated gate bipolar transistor module and propagates by increasing the diameter. The effect of the bonding type on power cycling fatigue life is also discussed. The fracture process was found to depend on the type of bonding. Lead frame bonding was found to be more effective than wire bonding.

Reliability Evaluation on Deterioration of Power Device Using Coupled Electrical-Thermal-Mechanical Analysis

For power electronics devices, the reliability of thermal fatigue induced by power cycling has been prioritized as an important concern. Since power cycling produces non-uniform temperature distribution in the device, coupled thermal- structure analysis is required to evaluate thermal fatigue mechanism. The thermal expansion difference between a package and a substrate causes thermal fatigue. Many studies on thermal fatigue in electronics devices have been reported but temperature is often assumed to be uniform under thermal cycling environment. In this study, thermal fatigue of solder joints on power electronics device was evaluated. Joule heating produces temperature distribution, which affects the behavior of thermal fatigue. The finite element method (FEM) was used to evaluate temperature distribution induced by joule heating. Higher temperature appears below the bonded wire because the electric current flow through the bonding wire. Coupled thermal-structure analysis was also performed to evaluate the inelastic strain distribution. The damage of each element can be calculated from equivalent inelastic strain range and crack propagation was simulated by deleting damaged elements step by step. The crack initiates below the bonded wire and propagates concentrically under power cycling. There is the difference from environmental thermal cycling where the crack initiates at the edge of solder.

Reliability Evaluation for Power Electronics Device using Electrical Thermal and Mechanical Analysis

This paper presents a fundamental method to evaluate thermal fatigue life of power module Coupled electrical-thermal analysis was performed to obtain the distribution of temperature due to electric current Then, thermo-mechanical analysis was carried out to calculate inelastic strain range generated in a solder joint Crack path simulation technique was used to evaluate total fatigue life and rise in temperature Fatigue crack initiates under Al bonding wire for the IGBT module Crack propagation induces the change in thermal properties of power devices Total fatigue life changes with configuration of model

Reliability evaluation on deterioration of power device using coupled electrical-thermal-mechanical analysis

To calculate power semiconductor device fatigue with high accuracy, multiphysics analysis comprising electrical, heat, and stress analyses is presented. Power semiconductor devices (e.g., IGBTs) have been widely used in various applications. In particularly, the power semiconductor device (IGBT) becomes important component in vehicle applications. There is a high demand for compact and high-power capacity next-generation vehicles such as electric vehicles and hybrid vehicles. However, it causes the problem such as thermal stress. The reliability of power semiconductor devices has to be investigated by carrying out highly accurate simulations before developing IGBTs. In this paper, the electrical conductivity in silicon (IGBT) is considered as the material parameter. The semiconductor resistance is calculated by voltage distributions in the semiconductor. Comparing the conductivity constant case with the conductivity variation case, we examine the effects of the electrical characteristics of the semiconductor on fatigue.Copyright © 2009 by ASME

Takashi Anzawa

Papers

Power cycle fatigue reliability evaluation for power device using coupled electrical-thermal-mechanical analysis

Reliability Evaluation on Deterioration of Power Device Using Coupled Electrical-Thermal-Mechanical Analysis

Reliability Evaluation for Power Electronics Device using Electrical Thermal and Mechanical Analysis

Reliability evaluation on deterioration of power device using coupled electrical-thermal-mechanical analysis

High-Accuracy Fatigue Evaluation of Power Devices by Multi-Coupled Analysis