Lifetime Model for the Fatigue Fracture in Cu/Al2O3/Cu Composites: Experimental Validation of a Substantial Lifetime Enhancement by Cu Step Etching

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Patrick Gaiser ◽  
Markus Klingler ◽  
Jürgen Wilde

Abstract Direct bonded copper (DBC) alumina (Al2O3) substrates are used in power electronic devices in order to transfer the heat from semiconductor devices to the heat sink and to carry high electric currents. Fatigue-induced cracks in the ceramic result in a diminished heat dissipation, leading to failure of a power device. Hence, a lifetime model concerning this failure mode is necessary. In this paper, a new lifetime model including crack initiation as well as crack propagation for the fatigue fracture of Al2O3-based DBC substrates is presented. It is based on experimental crack detection techniques and finite element method (FEM) simulations including fracture mechanics. For the validation of the lifetime model, experiments are presented which show that by appropriate design of the copper edge, the lifetime of the substrates is increased substantially.

Author(s):  
Patrick W. Wilkerson ◽  
Andrzej J. Przekwas ◽  
Chung-Lung Chen

Multiscale multiphysics simulations were performed to analyze wirebonds for power electronic devices. Modern power-electronic devices can be subjected to extreme electrical and thermal conditions. Fully coupled electro-thermo-mechanical simulations were performed utilizing CFDRC’s CFD-ACE+ multiphysics simulation software and scripting capabilities. Use of such integrated multiscale multiphysics simulation and design tools in the design process can cut cost, shorten product development cycle time, and result in optimal designs. The parametrically designed multiscale multiphysics simulations performed allowed for a streamlined parametric analysis of the electrical, thermal, and mechanical effects on the wirebond geometry, bonding sites and power electronic device geometry. Multiscale analysis allowed for full device thermo-mechanical analysis as well as detailed analysis of wirebond structures. The multiscale simulations were parametrically scripted allowing for parametric simulations of the device and wirebond geometry as well as all other simulation variables. Analysis of heat dissipation from heat generated in the power-electronic device and through Joule heating were analyzed. The multiphysics analysis allowed for investigation of the location and magnitude of stress concentrations in the wirebond and device. These stress concentrations are not only investigated for the deformed wirebond itself, but additionally at the wirebond bonding sites and contacts. Changes in the wirebond geometry and bonding geometry, easily changed through the parametrically designed simulation scripts, allows for investigation of various wirebond geometries and operating conditions.


Author(s):  
Jing Li ◽  
Shuanshi Fan ◽  
Zemin Yao ◽  
Jing Li ◽  
Xinli Wei

In this paper, in order to solve the problem of intensified heat dissipation in high power electronic devices, a fast transient and intensified heat dissipation technology was put forward by comparing many heat transfer modes based on the analytical study on the existing technologies about heat dissipation at high heat flux density and about fast heat transport. This technology combined spray cooling technology with fast endothermic chemical reaction processes; we summarized the characteristics of media applicable to an environment with transient high heat flux density by comparing various parameters of many sprayed media in the spray cooling process. According to the energy balance of endothermic chemical reactions of relevant media, we determined the media (mainly carbon dioxide hydrate) applicable to the fast transient and intensified heat dissipation technology and presented the conditions for the chemical reactions. We analyzed the methods controlling the instantaneous chemical reaction rate and proposed the structural characteristics of the chemical reactor so as to ensure that the time for heat removal will be control to around 0.01 second. Thus, the problem of fast transient heat dissipation in high power electronic devices, etc. would be radically solved.


2013 ◽  
Vol 804 ◽  
pp. 378-382
Author(s):  
Bing Qi ◽  
Hong Wei Xie ◽  
Li Kun Zhang ◽  
Li Li Wang ◽  
Song Song Chen

Power electronic devices always consume a lot of energy, and this energy is then converted into heat, so that the device temperature rises. It will not only affect the device performance in full cycling, but also may result in damage, if the problem of heat dissipation can not be solved. In this paper, we propose an energy cycle approach that can provide a full utilization of the reused energy from the expansion tank to distributed pump. The Power distribution analysis of the controlling cabinet is presented together with the component in power cabinet. With the capacity of power electronic devices and power levels increasing rapidly, the thermal performance of the cooling system can be improved and higher requirements can be obtained.


Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4176 ◽  
Author(s):  
Chaoqun Jiao ◽  
Juan Zhang ◽  
Zhibin Zhao ◽  
Zuoming Zhang ◽  
Yuanliang Fan

With the development of China’s electric power, power electronics devices such as insulated-gate bipolar transistors (IGBTs) have been widely used in the field of high voltages and large currents. However, the currents in these power electronic devices are transient. For example, the uneven currents and internal chip currents overshoot, which may occur when turning on and off, and could have a great impact on the device. In order to study the reliability of these power electronics devices, this paper proposes a miniature printed circuit board (PCB) Rogowski coil that measures the current of these power electronics devices without changing their internal structures, which provides a reference for the subsequent reliability of their designs.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4654
Author(s):  
Andrzej Wetula ◽  
Andrzej Bień ◽  
Mrunal Parekh

Measurements of medium and high voltages in a power grid are normally performed with large and bulky voltage transformers or capacitive dividers. Besides installation problems, these devices operate in a relatively narrow frequency band, which limits their usability in modern systems that are saturated with power electronic devices. A sensor that can be installed directly on a wire and can operate without a galvanic connection to the ground may be used as an alternative voltage measurement device. This type of voltage sensor can complement current sensors installed on a wire, forming a complete power acquisition system. This paper presents such a sensor. Our sensor is built using two dielectric elements with different permeability coefficients. A finite element method simulation is used to estimate the parameters of a constructed sensor. Besides simulations, a laboratory model of a sensor was built and tested in a medium-voltage substation. Our results provide a proof of concept for the presented sensor. Some errors in voltage reconstruction have been traced to an oversimplified data acquisition and transmission system, which has to be improved during the further development of the sensor.


Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1717
Author(s):  
Camilo Andrés Ordóñez ◽  
Antonio Gómez-Expósito ◽  
José María Maza-Ortega

This paper reviews the basics of series compensation in transmission systems through a literature survey. The benefits that this technology brings to enhance the steady state and dynamic operation of power systems are analyzed. The review outlines the evolution of the series compensation technologies, from mechanically operated switches to line- and self-commutated power electronic devices, covering control issues, different applications, practical realizations, and case studies. Finally, the paper closes with the major challenges that this technology will face in the near future to achieve a fully decarbonized power system.


Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1581
Author(s):  
Xiaolong Chen ◽  
Jian Li ◽  
Shuowen Huang ◽  
Hao Cui ◽  
Peirong Liu ◽  
...  

Cracks are one of the main distresses that occur on concrete surfaces. Traditional methods for detecting cracks based on two-dimensional (2D) images can be hampered by stains, shadows, and other artifacts, while various three-dimensional (3D) crack-detection techniques, using point clouds, are less affected in this regard but are limited by the measurement accuracy of the 3D laser scanner. In this study, we propose an automatic crack-detection method that fuses 3D point clouds and 2D images based on an improved Otsu algorithm, which consists of the following four major procedures. First, a high-precision registration of a depth image projected from 3D point clouds and 2D images is performed. Second, pixel-level image fusion is performed, which fuses the depth and gray information. Third, a rough crack image is obtained from the fusion image using the improved Otsu method. Finally, the connected domain labeling and morphological methods are used to finely extract the cracks. Experimentally, the proposed method was tested at multiple scales and with various types of concrete crack. The results demonstrate that the proposed method can achieve an average precision of 89.0%, recall of 84.8%, and F1 score of 86.7%, performing significantly better than the single image (average F1 score of 67.6%) and single point cloud (average F1 score of 76.0%) methods. Accordingly, the proposed method has high detection accuracy and universality, indicating its wide potential application as an automatic method for concrete-crack detection.


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