集成电力电子模块封装的关键技术

封装技术直接影响到集成电力电子模块(Integrated Power Electronics Module,IPEM)的电气性能、EMI特性和热性能等,被公认为未来电力电子技术发展的核心推动力。介绍了IPEM封装的结构与互连和基板技术等关键技术及研究现状,分析了已存在的薄膜覆盖封装技术等三维IPEM封装技术,讨论了IPEM封装的发展趋势,最后指出我国IPEM封装技术研究的限制因素与对策。     

Flip-chip on flex integrated power electronics modules for high-density power integration

Three-dimensional flip-chip on flex (FCOF) integrated power electronics modules (IPEMs) have been fabricated for high-density power applications. In this FCOF-IPEM structure, solder-bumped devices were flip-soldered to a flexible substrate with electrical circuits etched on both sides. One side of the flex provides interconnection to power devices while the other is used to construct a simple gate-drive circuit; via holes through the flex integrate the power stage and gate-drive together. Solder-bumped MOSFET devices were obtained by a metallization processing and were used in the FCOF power module construction to improve thermal performance, power density, and integration. With this packaging approach, the multiple solder bumps, instead of the thin, long bonding wires were utilized to connect the power devices to the flex substrate and to improve heat dissipation, lower parasitic oscillations, and reduce package size. Reliability of solder joints has been dealt with through selection of materials, such as use of flexible substrates and underfill encapsulation, and design of joint shape for lower thermomechanical stresses. A comparative study of continuous switching test results have shown that the FCOF-IPEMs have better electrical performance than commercial wire bonded power modules.     

An overview to integrated power module design for high power electronics packaging

In recent years, there has been an explosion in demand for smaller and lighter, more efficient, and less expensive power electronic supplies and converters. There are a number of reasons for this recent necessity, ranging from the need for smaller and cheaper power converters for consumer electronics (such as laptop computers and cellular phones) to the need for highly reliable power electronics for such items as satellite and military craft power systems, which are required to be highly efficient, light in weight, smaller in volume, and low cost. This paper discusses the concept of Integrated Power Modules (IPMs), in which the electronic control circuitry and the high power electronics of the converter are integrated into a single compact standardized module. The advantages and disadvantages of such an approach will be discussed in reference to the current industry standard for power electronics design and packaging. The researchers will then take the readers through the IPM design, including basic circuit topology layout, module fabrication processes, and finally thermal considerations.     

Lifetime of power electronics interconnections in accelerated test conditions: High temperature storage and thermal cycling

We investigate the effect of three testing conditions (thermal shock, Rapid Temperature Change – RTC – and high temperature storage) on the interconnects of a power electronic module. In particular, the mechanical strength of thick aluminium wirebonds is investigated and shows that while it is not affected by storage at 230 °C, it is much more sensitive to thermal cycling. Shock tests are found to be especially severe, despite having a smaller temperature swing than RTC. Regarding the die attach, no noticeable reduction in mechanical strength is found, regardless of the ageing conditions, and despite clear micro-structural evolutions.     

Ultrasonics in integrated electronics

The capabilities of present integrated circuits are limited since only electrical interactions in solids are being utilized. The point of view is presented that additional degrees of freedom will be obtained in the future through the use of "Functional" electronic devices which also utilize mechanical, thermal, radiation, and/or magnetic phenomena. Development of these functional devices will come in response to pressure to overcome specific limitations imposed by present technology. In particular, no satisfactory substitute for an inductor is presently available in integrated electronics technology. The most serious limitation which results is the inability to achieve a narrow band-pass frequency response, a limitation which hinders the full exploitation of present capabilities in a wide variety of systems. Electromechanical resonators offer an extremely promising solution to this "tuning problem" because of their inherent compatibility of size and stability of Q and resonant frequency. Progress to date on integratable mechanically resonant devices covering the frequency range from less than 1 kc/s to more than 100 Mc/s is reviewed. These devices stimulate the imagination to conceive a variety of other new electromechanical devices. Therefore, it is predicted that the marriage of the ultrasonics and integrated electronics technologies will give birth to an exciting and fruitful new field of investigation.     

倒装芯片集成电力电子模块寄生参数的建模

采用球栅阵列芯片尺寸封装技术和倒装芯片(Flip Chip,FC)技术构建了半桥集成电力电子模块(Integrated Power Electronics Module,IPEM),半桥FC-IPEM实现三维封装结构。采用阻抗测量法提取模块寄生电感和寄生电容,建立模块的寄生参数模型,对模块进行电气性能测试。结果表明:半桥FC-IPEM构成的同步整流Buck变换器输出滤波电感中的电流波动幅度小于0.6A。     

Strategy and tactics for integrated electronics

The rate of technological innovation has been increasing dramatically in recent years, and so has the risk that a given technology may become obsolete before innovation is complete. Thus, tactical choices must be made on the basis of long-term goals. Probably nowhere is this problem more complex than in the move toward integrated electronics. By way of example, this article describes how the ``adaptive strategy' approach has been employed on a company-wide scale as a means for guiding the Bell System's choice of materials and processes for integration.     

A perspective on integrated electronics

Integrated-circuit technology may be expected to bring the price of complex electronic equipment within the sphere of industrial and consumer markets and, at the same time, make possible the development and use of significantly more powerful equipment, such as large computers, for military, government, and industrial applications. However, it is important to recognize that the basic ground rules of design are being drastically changed as is the internal structure of the ``classical' businesses.     

Making integrated electronics technology work

The keynote speaker at the recent International Solid State Circuits Conference implements the basic theme of the conference by presenting an overview of the success achieved in the field of integrated electronics ?and the problems remaining to be solved. He concentrates on three areas?digital, microwave, and consumer applications?because these best illustrate the successful implementation of the technology in the first case, and its possibilities, and problems, in the others.     

Switched-capacitor power electronics circuits

One of the main orientations in power electronics in the last decade has been the development of switching-mode converters without inductors and transformers. Light weight, small size and high power density are the result of using only switches and capacitors in the power stage of these converters. Thus, they serve as ideal power supplies for mobile electronic systems (e.g. cellular phones, personal digital assistants, and so forth). Switched-capacitor (SC) converters, with their large voltage conversion ratio, promise to be a response to such challenges of the 21st century as high-efficiency converters with low EMI emissions and the ability to realize steep step-down of the voltage (to 3 V or even a smaller supply voltage for integrated circuits) or steep step-up of the voltage for automotive industry or Internet services in the telecom industry. This paper is a tutorial of the main results in SC-converter research and design     

Automotive electronics power up

People are spending increasing amounts of time in their cars. As a result, automakers are equipping vehicles with more and more power-draining creature comforts as selling points. Cup holders have given way to navigational systems, separate driver and passenger climate controls, and surround sound and compact disk players. But performance and handling improvements under the hood, such as dynamic stability controls, electronic suspensions, and precision-controlled fuel injection, also need power from the 14-V system featured in today's cars. To handle the situation, automotive manufacturers and suppliers are embracing a 42-V standard for system voltage as they design new products. The challenge for designers, however, is that the cost of the new electronics cannot prohibit the economic production of automobiles. This hurdle must be cleared before cars with 42-V systems will become available to consumers. The paper discusses why 42 Volts was chosen, how many batteries will be needed, control systems, start/stop operation, and the influence of silicon devices on cost     

The evolution of power electronics

Distinctive attributes of power electronics equipment are high power capability, controllability and static switching to meet the goals of high efficiency and high dependability. Aspects of the early history of power electronics are traced from magnetic amplifiers, thyratrons, and ignitrons to power semiconductors     

Lifetime management of power transformers

Power transformers belong to the most important and most cost-intensive equipment of electrical power transmission and distribution. If an error in a transformer occurs, this causes not only an interruption of the electrical power supply of far areas but also large economic losses beyond that. Thus, the operation of transformers must guarantee a continuous and error free power supply over decades. Occurring errors and thus self-announcing possible failures of transformers should be detected in time, in order to initiate suitable measures for error correction. A continuous entry of the isolation status can prevent large errors, extend service life of the system and optimize maintenance. Thus, apart from higher system availability an avoidance of unplanned disconnections and expensive repairs are achieved. The emphasis of this contribution is to present methods which permit a substantially more exact and more reliable predicate about the current status of the isolation system of liquid-isolated power transformers.     

无电池电子设备的驱动方法

双层电容器技术的最新发展已使它能够代替特定二次电力存储应用中的再充电电池(参考文献1)。电容器提供了相对于再充电电池的明显优势,其中包括实际无限次数的充电/放电周期、短路情况下的生存能力、只需要过压保护的简单充电     

Recent advances in power electronics

Recent advances in several key areas of power electronics technology, such as power semiconductor devices, power converter circuits, and control of power electronics, are discussed. The structure and characteristics of IGBT, SIT, SITH, and MCT devices are reviewed. The principal converter types and their recent trends are described. A brief review of power integrated circuits is included. The features of microcomputer and VLSI control are described, and recent advances in microcomputers are highlighted. The principles of expert systems, fuzzy control, and neural networks are presented     

A project-oriented power electronics laboratory

This paper presents a power electronics educational laboratory suitable for undergraduate and graduate students. The pedagogical approach taken is one where the students revisit previously studied material placed in a practical context. This approach supports the prerequisite lecture material and allows study of some practical issues which are best handled in a laboratory setting. The course format makes the students gradually more responsible for the design of control circuitry which permits nominal operation of generic power converters. The laboratory experience culminates in a project where the student analyzes, designs, simulates and demonstrates a power electronics related topic     

Capacitive components for power electronics

As the consumer and industrial requirements for compact, high-power density electrical power systems grow substantially over the next decade, development of high power/energy density capacitor technology is a major enabling technology component element. For microsecond to fractional-second electrical energy storage, discharge, filtering, and power conditioning, capacitor technology is unequalled in flexibility and adaptability to meet a broad range of requirements in the future