Status and Trend of Power Semiconductor Module Packaging for Electric Vehicles

Power semiconductor modules are the core components in power-train system of hybrid and electric vehicles (HEV/EV). With the global interests and efforts to popularize HEV/EV, automotive module has become one of the fast growing sectors of power semiconductor industry. However, the comprehensive requirements in power, frequency, efficiency, robustness, reliability, weight, volume, and cost of automotive module are stringent than industrial products due to extremely high standards of vehicle safety and harsh environment. The development of automotive power module is facing comprehensive challenges in designing of structure, material, and assembly technology. In this chapter, the status and trend of power semiconductor module packaging for HEV/EV are investigated. Firstly, the functionality of power electronics and module in HEV/EV power-train system, as well as the performance requirements by automotive industry, is addressed. A general overview of HEV/EV module design and manufacturing is discussed. Then, the typical state-of-the-art commercial and custom HEV/EV power modules are reviewed and evaluated. Lastly, the packaging trends of automotive module are investigated. The advanced assembly concept and technology are beneficial to thermal management, minimized parasitic parameters, enhancement of thermal and mechanical reliability, and the reduction of weight, volume, and cost

Next generation electric drives for HEV/EV propulsion systems: Technology, trends and challenges

In recent decades, several factors such as environmental protection, fossil fuel scarcity, climate change and pollution have driven the research and development of a more clean and sustainable transport. In this context, several agencies and associations, such as the European Union H2020, the United States Council for Automotive Research (USCAR) and the United Nations Economic and Social Commission for Asia (UN ESCAP) have defined a set of quantitative and qualitative goals in terms of efficiency, reliability, power losses, power density and economical costs to be met by next generation hybrid and full electric vehicle (HEV/EV) drive systems. As a consequence, the automotive electric drives (which consists of the electric machine, power converter and their cooling systems) of future vehicles have to overcome a number of technological challenges in order to comply with the aforementioned technical objectives. In this context, this paper presents, for each component of the electric drive, a comprehensive review of the state of the art, current technologies, future trends and enabling technologies that will make possible next generation HEV/EVs.This work has been partially supported by the Department of Education, Linguistic Policy and Culture of the Basque Government within the fund for research groups of the Basque university system IT978-16, by the Ministerio de Economía y Competitividad of Spain within the project DPI2014-53685-C2-2-R and FEDER funds and by the Government of the Basque Country within the research program ELKARTEK as the project KT4TRANS (KK-2015/00047 and KK-2016/00061), as well as by the program to support the specialization of Ph.D researchers at UPV/EHU ESPDOC16/25

The role of power device technology in the electric vehicle powertrain

In the automotive industry, the design and implementation of power converters and especially inverters, are at a turning point. Silicon (Si) IGBTs are at present the most widely used power semiconductors in most commercial vehicles. However, this trend is beginning to change with the appearance of wide-bandgap (WBG) devices, particularly silicon carbide (SiC) and gallium nitride (GaN). It is therefore advisable to review their main features and advantages, to update the degree of their market penetration, and to identify the most commonly used alternatives in automotive inverters. In this paper, the aim is therefore to summarize the most relevant characteristics of power inverters, reviewing and providing a global overview of the most outstanding aspects (packages, semiconductor internal structure, stack-ups, thermal considerations, etc.) of Si, SiC, and GaN power semiconductor technologies, and the degree of their use in electric vehicle powertrains. In addition, the paper also points out the trends that semiconductor technology and next-generation inverters will be likely to follow, especially when future prospects point to the use of “800 V" battery systems and increased switching frequencies. The internal structure and the characteristics of the power modules are disaggregated, highlighting their thermal and electrical characteristics. In addition, aspects relating to reliability are considered, at both the discrete device and power module level, as well as more general issues that involve the entire propulsion system, such as common-mode voltage.This work has been supported in part by the Government of the Basque Country through the fund for research groups of the Basque University System IT1440-22 and the Ministerio de Ciencia e Innovación of Spain as part of project PID2020-115126RB-I00 and FEDER funds. Finally, the collaboration of Yole Développement (Yole) is appreciated for providing updated data on its resources

Stepwise Design Methodology and Heterogeneous Integration Routine of Air-Cooled SiC Inverter for Electric Vehicle

Carrying on SiC devices, the air-cooled inverter of the electric vehicle (EV) can eliminate the traditional complicated liquid-cooling system in order to obtain a light and compact performance of the powertrain, which is considered as the trend of next-generation EV. However, the air-cooled SiC inverter lacks strategic design methodology and heterogeneous integration routine for critical components. In this article, a stepwise design methodology is proposed for the air-cooled SiC inverter in the power module, dc-link capacitor, and heat sink levels. In the power module level, an electrical-thermal-mechanical multiphysics model is proposed. The multidimension stress distribution principles in a six-in-one SiC power module are demonstrated. An improved power module is presented and confirmed by using the observed multiphysics design principles. In the dc-link capacitor level, ripple modeling of the inverter and capacitor are created. Considering the tradeoffs among ripple voltage, ripple current, and cost, optimal strategies to determine the material and minimize the capacitance of the dc-link capacitor are proposed. In the heat sink level, thermal resistance of air-cooled heat sink is modeled. Structure and material properties of the heat sink are optimally designed by using a comprehensive electro-thermal analysis. Based on the optimal design results, the prototypes of the customized SiC power module and heterogeneously integrated air-cooled inverter are fabricated. Experimental results are presented to demonstrate the feasibility of the designed and manufactured air-cooled SiC inverter.Ministry of Education (MOE)Nanyang Technological UniversityThis work was supported in part by the National Natural Science Foundation of China under Grant 51607016, in part by the National Key Research and Development Program of China under Grant 2017YFB0102303, and in part by the Singapore ACRF Tier 1 Grant RG 85/18. The work of X. Zhang was supported by the NTU Startup Grant (SCOPES)

Thermal design and characterization of a modular integrated liquid cooled 1200 V-35 A SiC MOSFET bi-directional switch

The aim of this work is the thermal design of a modular direct liquid cooled package for 1200 V–35 A SiC power MOSFETs, in order to take full advantage of the high power density and high frequency performance of these devices, in the development of a modular integrated solution for power converters. An accurate electro-thermal fluid dynamic model is set up and validated by thermal characterization on a prototype; numerical models have been used to study the internal temperature distribution and to propose further optimization

An analysis of the thermal interaction between components in power converter applications

Accurately predicting the temperature of semiconductor devices is very important in the initial design of power electronics converter. RC thermal models derived from well-known methods have some ability to predict the temperature. However, the accuracy is boundary condition specific, hence, these methods cannot be used in the reliability analysis. To make the thermal model more accurate and robust the factors contributing to discrepancies need to be analyzed carefully. These are power-module-materials’ non-linear properties, thermal grease layer and the cooling system (i.e., liquid-cooled cold plate). In this work, estimation of accurate RC parameters from FEA thermal model is demonstrated in COMSOL. The electrical model having temperature dependent power loss model is coupled to refined thermal model and solved in a circuit simulator, PLECS. The proposed method is applied in two applications: assessing thermal interaction between IGBTs and anti-parallel diodes in a half-bridge power module, and assessing thermal interaction among the discrete switches in an interleaved bidirectional DC-DC converter. Results show that the impact of material non-linearity, thermal grease layer and cooling boundary conditions are significant for accurate prediction of IGBT and diode temperatures. The proposed model is consistent to FEA results and differs by 2-6.5% comparing to the experimental results

Integrated motor drives: state of the art and future trends

With increased need for high power density, high efficiency and high temperature capabilities in Aerospace and Automotive applications, Integrated Motor Drives (IMD) offers a potential solution. However, close physical integration of the converter and the machine may also lead to an increase in components temperature. This requires careful mechanical, structural and thermal analysis; and design of the IMD system. This paper reviews existing IMD technologies and their thermal effects on the IMD system. The effects of the power electronics (PE) position on the IMD system and its respective thermal management concepts are also investigated. The challenges faced in designing and manufacturing of an IMD along with the mechanical and structural impacts of close physical integration is also discussed and potential solutions are provided. Potential converter topologies for an IMD like the Matrix converter, 2-level Bridge, 3-level NPC and Multiphase full bridge converters are also reviewed. Wide band gap devices like SiC and GaN and their packaging in power modules for IMDs are also discussed. Power modules components and packaging technologies are also presented

Thermal Management of Electrified Propulsion System for Low-Carbon Vehicles

An overview of current thermal challenges in transport electrification is introduced in order to underpin the research developments and trends of recent thermal management techniques. Currently, explorations of intelligent thermal management and control strategies prevail among car manufacturers in the context of climate change and global warming impacts. Therefore, major cutting-edge systematic approaches in electrified powertrain are summarized in the first place. In particular, the important role of heating, ventilation and air-condition system (HVAC) is emphasised. The trends in developing efficient HVAC system for future electrified powertrain are analysed. Then electric machine efficiency is under spotlight which could be improved by introducing new thermal management techniques and strengthening the efforts of driveline integrations. The demanded integration efforts are expected to provide better value per volume, or more power output/torque per unit with smaller form factor. Driven by demands, major thermal issues of high-power density machines are raised including the comprehensive understanding of thermal path, and multiphysics challenges are addressed whilst embedding power electronic semiconductors, non-isotropic electromagnetic materials and thermal insulation materials. Last but not least, the present review has listed several typical cooling techniques such as liquid cooling jacket, impingement/spray cooling and immersion cooling that could be applied to facilitate the development of integrated electric machine, and a mechanic-electric-thermal holistic approach is suggested at early design phase. Conclusively, a brief summary of the emerging new cooling techniques is presented and the keys to a successful integration are concluded