The robustness of series-connected high power IGBT modules

The behaviour in terms of robustness of series-connected high power IGBT modules is presented, arranged in a topology which ensures voltage balance on IGBT’s and diodes by means of a simple auxiliary circuit applied directly on the high power devices, which are used in hard switching mode. Analyses in terms of IGBT and diode SOA (safe operating area), collector to emitter voltage gradient and short circuit condition are reported as well as an extended experimental characterisation. Both analyses confirm superior switching rating and system reliability, by using two series-connected IGBT in substitution of a single module, same current and double voltage rated. Moreover, thanks the auxiliary circuit presence, the robustness of total system is maintained also in extreme operating conditions.     

Substrate-to-base solder joint reliability in high power IGBT modules

Acoustic microscope imaging proved to be an excellent tool to detect and quantify solder fatigue of the substrate to base interface of high power IGBT modules. This technique was used to establish the dependence of the thermal cycling capability on the temperature swing of the module base for a A1N/Cu system. Results from temperature cycling tests were combined with results from power cycling tests to predict the solder joint reliability over a wide range of temperature excursions.     

Instable mechanisms during unclamped operation of high power IGBT modules

The behaviour in terms of robustness during unclamped operations of power IGBT modules is presented. The experimental characterization is aimed to identify the main instable phenomena during unclamped turn-off in power IGBT modules. Several devices of different generations, current and voltage ratings have been analyzed. Thanks to a non-destructive experimental set-up, it is possible to observe instable phenomena without causing the damage of the device under test. In this paper, it is shown that the destructive conditions during unclamped operations are preceded by precursors on the gate side which indicate instable phenomena taking place inside the device. The dependence of the destructive phenomenon on the driver conditions are widely and exhaustively analyzed.     

Degradation mapping in high power IGBT modules using four-point probing

An electrical four-point probing approach is used to estimate local degradation in high power insulated gate bipolar transistor modules subjected to power cycling. By measuring electrical parameters of selected units and components the possibility of mapping the degradation is demonstrated. The development of failures is put in accordance with physical phenomena and materials fatigue. These results are directly usable for reliability purposes with a focus on geometry optimization and enhanced lifetime prediction methods.     

Double-sided cooling for high power IGBT modules using flip chiptechnology

A new technique for the packaging of IGBT modules has been developed. The components are sandwiched between two direct bond copper (DBC) substrates with aluminum nitride. Wire bonds are replaced with flip chip solder bumps, which allows cooling of components on both sides. Microchannel heat sinks are directly integrated in the package to decrease the thermal resistance of the module. Thus, a very compact module with high thermal performance is obtained. A prototype with two insulated gate bipolar transistors (IGBTs) and four diodes associated in parallel was realized and tested. In this paper, the innovative packaging technique is described, and results of thermal tests are presented     

Thermal characterization of IGBT power modules

In this paper we report on experimental techniques for the thermal characterization of IGBT power modules. Three different systems have been used: the first one performs “in-time” characterization in order to control the most significant device parameters during normal operation or stress tests; the second one is for a complete and dynamic thermal characterization; finally, infrared optical analysis has been performed to validate the results.     

Temperature measurements and thermal modeling of high power IGBT multichip modules for reliability investigations in traction applications

To study the failure mechanisms induced on high power IGBT multichip modules by thermal cycling stress in traction environment, a good knowledge of the temperature distribution and variations on the chips and in the interfaces between the different layers of the packaging is necessary. This paper presents a methodology for contact temperature measurements on chips surface in power cycling conditions and a fast 3D thermal simulation tool for multilayered hybrid or monolithic circuits. The results of static and dynamic thermal simulation of a 1200A–3300V IGBT module are given and compared with the contact temperature measurements results. The investigation has been done within the RAPSDRA (Reliability of Advanced High Power Semiconductor Device for Traction Applications) European project.     

Static and dynamic finite element modelling of thermal fatigue effects in insulated gate bipolar transistor modules

The aim of this paper is to demonstrate the use of finite element techniques for modelling thermal fatigue effects in solder layers of insulated gate bipolar transistor (IGBT) – modules used in traction applications. The three-dimensional models presented predict how progressive solder fatigue, affects the static and dynamic thermal performance of such devices.Specifically, in this paper, the analysis of an 800 A–1800 V IGBT module is performed. In the first part, the static analysis is realised. The parameters assessed are thermal resistance, maximum junction temperature and heat flux distribution through the different layers comprising the module construction. In the second part of the paper, transient analyses are performed in order to study the dynamic thermal behaviour of the module. The constructed thermal impedance curves allow for calculation of the device temperature variations with time. Stress parameters, such as temperature excursion and maximal temperature at chip and solder interfaces, are determined. Calibration of all simulation models is achieved by comparison with alternative theoretical calculations and manufacturers’ measured values provided in the data sheet book.     

Thermal fatigue effects on the temperature distribution inside IGBT modules for zone engine aeronautical applications

This work examines the thermal fatigue effects on the temperature distribution inside IGBT modules for aeronautical applications. Exactly, they are used in a very different application where temperature cycling due to the working environment is the most limiting fact. In this case, it is concluded that solder delamination does not present any restriction to module lifetime at short term (up to 60% of total delaminated area). In addition, it is proposed only determining the delaminated area behind devices, which is the main responsible of the thermal temperature increase.     

大功率IGBT功耗的研究

绝缘栅双极晶体管(IGBT)是复合全控型电压驱动式功率半导体器件.为了改善其功耗性能并进行进一步优化,论文在阐述IGBT特性基础上,通过从器件构成和实际应用角度对影响功率器件功耗的主要因素进行分析,并结合实践对IGBT功率器件的功耗进行深入研究,由此可以更深刻地理解IGBT功耗的产生,这对正确选择和使用IGBT器件及其系统有一定的实用价值.     

Reliability and lifetime evaluation of different wire bonding technologies for high power IGBT modules

IGBT modules for power transmission, industrial and traction applications are operated under severe working conditions and in harsh environments. Therefore, a consequent design, focused on quality, performance and reliability is essential in order to satisfy the high customer requirements. One of the main failure mechanisms encountered in high power IGBT modules subjected to thermal cycles is wire bond lift-off, which is due to the large thermal expansion coefficient mismatch between the aluminum wires and the silicon chips. The paper describes various bonding technologies using different wire materials directly bonded onto chip metallisation as well as the ABB solution where the wire is bonded on a thin molybdenum strain buffer soldered onto the chip. We assess in the present paper the potential of these technologies to enhance module reliability and lifetime through a power cycling test. Failure analysis results are presented and the failure mechanisms related to each technology are explained in detail.     

Analysis on the difference of the characteristic between high power IGBT modules and press pack IGBTs

The insulated gate bipolar transistor (IGBT) has been widely employed in such applications as alternate current motors and inverters for its lower driving power and lower on-state voltage. IGBT modules and press pack IGBTs are the most commonly used packaging for high-voltage and high-power-density applications. The difference in the packaging style and working conditions between IGBT modules and press pack IGBTs creates distinctions in, for instance, the thermal characteristics and reliability. Those distinctions lead to different applications and working conditions. In this paper, the development of IGBT devices has been reviewed, including the distinction of IGBT modules and press pack IGBTs in packaging style. Most importantly, the thermal and reliability characteristics have been compared in detail and the applications that are most suitable for IGBT modules and press pack IGBTs were outlined. The comparison of the thermal characteristics, reliability and applications provides guidance for users to take full advantage of the devices according to their requirements.     

高压IGBT模块局部放电研究现状

IGBT(Insulated Gate Bipolar Transistor)模块一直朝着更高耐压和更大电流密度的方向发展,因模块内部电气绝缘和局部放电引起的问题也越来越明显。在高电压IGBT模块封装中,通常使用硅凝胶和环氧树脂来对模块进行灌注和密封,以满足其高电场承受能力,提升整个模块的绝缘性能和局部放电表现。目前很多国内外学者已经在这方面进行一系列研究,主要目的在于优化IGBT模块内部的电场分布。本文重点介绍目前研究的几种可以改善IGBT内部电场分布状态的方法,并对局部放电可靠性的提升方法进行总结。     

The high frequency behaviour of high voltage and current IGBT modules

Sharp voltage gradients act as a stimulus for high power IGBT modules, which can exhibit a potentially instable high frequency behaviour. In fact, they can act as a radio frequency amplifier and, in particular operating conditions, the interaction between the device and the control or the external circuit can cause self-sustaining oscillations or the enhancement of the unevenness in current distribution inside a power module thus having a significant impact on the reliability of the power converter. Moreover, this RF amplification worsen the generated EMI (Electro Magnetic Interference). This paper presents an extensive experimental investigation about the high frequency behaviour of IGBT high power modules. The measurements were performed by means of an original experimental set-up that was specifically conceived and constructed. The data are analysed with the help of a theoretical small signal model which is able to describe RF behaviour of high power IGBT modules.     

对大功率IGBT模块损耗的研究

大功率IGBT模块损耗的确定是三相PWM变流器设计的一个关键参数。文中对两种类型转换器的功率半导体损耗进行了完整的分析计算。所提出的计算基础是将大功率IGBT的损耗简化为传导损耗和转换损耗。这种近似计算方法有助于预测和进一步研究两种变流器的功率IGBT的损耗性能。仿真计算结果指出了大功率IGBT损耗与变流器类型、工作点和脉冲宽度调制度的相关性,证明了所提出的计算方法的有效性。     

TLM method for thermal investigation of IGBT modules in PWM mode

The insulated gate bipolar transistor (IGBT) is popularly used in high power, high frequency power-electronic applications such as motor control and inverters. These applications require well designed thermal management system to ensure the protection of IGBTs. Choice simulation tools for accurate prediction of device power dissipation and junction temperature become important in achieving optimised designs.In this paper, thermal analysis of a 1200 A, 3.3 kV IGBT module was investigated and analysed using the three-dimensional transmission line matrix (3D-TLM) method. The results show a three-dimensional visualisation of self-heating phenomena in the device. Since the comparison TLM results with the analytical solutions do not exist for this IGBT module, we use the MSC.NASTRAN tool to find the similar range of the temperatures. Results are compared.Typically, IGBT is used in a three-phase inverter leg where the control signals are generated via PWM scheme so, the prediction of the temperature rise is important in the pulse operation conditions for the IGBT device. A view of the dynamic thermal temperature rise is obtained with 100 W-step pulse dissipation applied at IGBT chips. The temperature rises are calculated using TLM method during the PWM load cycles. Simulations give clear indications of the importance of the spreader material and are helpful in selecting the proper one.TLM has been successful in modelling heat diffusion problems and has proven to be efficient in terms of stability and complex geometry. The three-dimensional results show that method has a considerable potential in power devices thermal analysis and design.     

Effects of current density and chip temperature distribution on lifetime of high power IGBT modules in traction working conditions

This paper deals with ageing parameters of high power IGBT modules in traction applications. Using the results of a great number of power cycling tests on 400A modules, it shows that, in addition to the junction temperature excursion, other parameters like the maximal chip temperature and the current density are involved in thermal fatigue failures. Besides, contact temperature measurements achieved on IGBT chip surface in cycling conditions to localise the maximal thermomechanical stress are presented and correlated with modules failure analysis. The role of the current density in the ageing process is finally shown by determining its influence on the temperature gradient on chip surface.     

功率半导体IGBT热击穿失效的可靠性研究

针对变频空调使用缘栅双极型晶体管（IGBT）击穿短路故障进行分析,确认IGBT为过压损坏失效。,空调供电电源出现大的波动影响芯片供电电源质量,电压偏低导致IGBT开通异常,不能及时欠压保护,IGBT长时间处于工作在放大状态,IGBT开通损耗大热击穿失效。本文主要从电路设计,工作环境,模拟验证等方面分析研究,确认IGBT击穿短路失效原因,从设计电路与物料选型优化提升产品工作可靠性。     

高压大功率IGBT元器件开关特性的分析研究

自从IGBT器件出现之后,大量的研究人员对IGBT器件的开关特性进行了大量的研究,以便准确地预测和改善器件的开关瞬态特性.在实际应用中,IGBT器件的开关特性不仅和其物理结构、制作工艺以及工作的原理有着密切的关系,同时和其工作的环境也具有密切的关系.在IGBT器件工作的时候,常常受到驱动电压和电阻以及工作电压、集电极电流等的影响.因此研究工作环境对IGBT器件开关特性的影响,不断地改善其设计来优化其性能,成为研究的重点.论文详尽研究分析了功率器件IGBT的开关特性,对IGBT及其系统的理解、应用具有一定的指导意义.