Converter concepts to increase the integration level

In the previous work, a way to improve packaging of power electronic converters by increasing integration level and using multifunctional construction parts is presented. The quantities intended to evaluate integration level and volumetric utilization in power converters are introduced. Based on these values, a number of methods to increase the integration level are presented. A design process in the form of a flow chart that implements these methods in concrete design problems is presented. In this paper, the design process is applied to a dc/dc 42/14-V converter for automotive applications. Utilizing commercially available technologies that lend themselves to mass production this design process results in three packaging concepts, namely lead frame converter, printed circuit board embedded converter, and heat conductor converter. These concepts are then compared to a benchmark converter implemented in the conventional, discrete packaging technology. It is shown that by smart use of parts in the converter construction, the high values of integration level and high power densities can be achieved.     

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.     

Three-Dimensional Packaging for Power Semiconductor Devices and Modules

Demands for increasing power density and levels of functional integration in switch-mode power converters require power electronics manufacturers to develop innovative packaging solutions for power semiconductor devices and modules. Three-dimensional (3-D) packaging techniques offer the potential of lower resistance, higher current handling capability, smaller volume, better thermal management capability, and high reliability. In this paper, we present the constructions and some electrical and thermomechanical analyses of four 3-D packaging approaches that have been developed within the Center for Power Electronics Systems—an NSF Engineering Research Center.     

Power electronic interconnects: skin- and Proximity-Effect-based frequency Selective-Multipath propagation

Structural electromagnetic effects, attributed to the packaging and construction of power electronic converters, are often seen as detrimental and it is attempted to eliminate these "parasitics." This paper explores the utilization of some of these structural electromagnetic effects to achieve higher levels of functional integration in modules by obtaining low-pass filtering for various applications by controlling the material and geometry of selected interconnecting structures. Multipath propagation with frequency selective attenuation is one of the promising new technologies presented. Modeling and experimental results are given for a number of different cases showing promise for future integration into power electronic products as currently discussed in the literature. The conclusion reached from the research is that phenomena like the skin and proximity effect that are often considered as detrimental and to be avoided or minimized, can indeed be controlled and used to enhance the operation of power electronic systems.     

Power electronic converter and system control

This paper deals with modern control systems technology that is frequently applied to power conversion systems. The discussion goes far beyond the basic level of switch control in switching regulators. System-level control issues are important in expanding the market base of power electronics. Improvement in system performance involves not only the use of advanced control techniques, but also the integration of several converters or converter systems into a larger system. A fully controlled rectifier and an induction motor drive system are presented as typical applications to illustrate the use of many techniques for controlling power converters. The paper then points out how a wide variety of control techniques can be applied to enhance the controller performance and bandwidth in power electronics. These techniques include observers and adaptive control, nonlinear control, sliding and dead-beat control, and intelligent control. Finally, the paper points out how power electronic system performance can be enhanced through the use of condition monitoring and diagnostics     

绿色电子制造及绿色电子封装材料

阐述了绿色电子制造(包括电子封装)概念起源、定义以及基本内涵和范畴,并从电子封装用互连材料、被连接材料和封装后清洗过程这三个方面全面阐述了绿色电子封装的主要内容,重点评述了目前绿色电子封装材料(包括无铅钎料、钎剂、焊膏和导电胶等)的研究现状和面临的问题.最后,展望了绿色电子制造及绿色电子封装材料的未来发展趋势.     

Table of contents

The following topics are dealt with: electronic ballasts; uninterruptible power supply systems; power converters; power inverters; power electronics control; power quality; renewable energy; EMI-EMC; and power electronic drives.     

面向电子制造业的集成MES应用技术的研究

随着电子制造业的快速发展,智能信息化技术在电子制造业中也得到了普遍的应用.电子制造业不仅要提高产品的质量,而且还要在生产过程中对客户需要的相关的数据进行收集,数据报告是客户对电子制造商产品制造情况进行考核的一个重要的条件.本文对电子制造业中电子产品制造服务的业务需求进行了分析,构建了多种技术相融合的面向电子产品制造业的集成MES应用模型,对MES系统的具体功能进行了分析,对面向电子制造业的集成MES的应用技术进行了分析和研究.     

A three-phase to three-phase series-resonant power converter withoptimal input current waveforms. I. Control strategy

A control strategy for multiphase-input multiphase-output AC to AC series-resonant (SR) power converters is presented. After reviewing some basics in SR power converters, a hierarchy of control mechanisms is presented, together with their respective theoretical backgrounds and practical limitations. The respective controllers are then presented in a simulation context. The control scheme fully exploits the capabilities of high-frequency power converters and facilitates the extraction of currents at a unity power factor from the supply side, even under transient conditions. The control scheme takes into account losses and inaccuracies in the control electronics without deteriorating the intended waveforms. Through computer simulation, it has been shown that, in particular, the input current wave-shapes are greatly improved compared to the best-available operating data     

LTCC package for high temperature applications

There is a growing demand for sensors and electronics that can work in harsh environments and at high temperature. Applications include sensors and actuators for control in petroleum and geothermal industry, process monitoring and distributed control systems in the automotive and aerospace fields. Process development and packaging materials for electronic devices are closely connected to such packaging issues. In many cases the package is as important as the device itself in meeting the applications needs.Low temperature co-fired ceramics (LTCC) and thick-film technologies have the potential to incorporate multilayer structures, enabling fabrication of specialized packaging systems. LTCC technology enables easy electrical or optical connections within and between layers in addition to enabling use of integrated passive components, heaters, sensors, converters etc.This paper presents attempts to develop a reliable packaging technology for silicon carbide (SiC) based hydrogen sensors operating at temperatures up to 300 °C. Some simulations of thermal properties were carried out and package structures were made and investigated. The package protects the sensor against mechanical damage and makes possible easy electrical connections. Moreover, the heater and temperature sensors allow for proper temperature regulation of the element. The manufacturing process, basic electrical parameters of the integrated heater as well as real temperature distribution are presented.     

Design of integrated magnetic elements using thick-film technology

One of the most important aims in the electronic industry is the integration of magnetic elements, since it allows the reduction of the size of power electronics equipment. This paper presents a method of designing integrated magnetic elements using thick-film technology. A DC-to-DC converter has been built and tested to validate this technology. Experimental results obtained and conclusions are also presented     

Packaging and integration technologies for future high-frequency power supplies

This paper reviews data from the International Technology Roadmap for Semiconductors to establish where dc-dc converters are headed in the first decade of the new millennium. It focuses on the high performance computing (high current, fast response, high power density) and portable/handheld (low profile) sectors. Magnetics and power device packaging technologies needed to allow power supplies to move to operating frequencies in the 1-10 MHz region are discussed. It introduces the concept of magnetic components fully embedded (windings and core) in PCB and silicon offering low profile and low losses at high frequency. It also reviews developments in wirebond-free power packaging such as flip-chip assembly that offer low profile, reduced parasitics and increased thermal performance. Finally, consideration is given to the changes in the power electronics industry that may need to be addressed to enable these new technologies to play a strategic role.     

Power electronics' polluting effects

In use far and wide for improved delivery and control of the electricity supply, power electronics systems are both the cause and remedy of the power system harmonic pollution problem. Here, the authors describe how an insidious side-effect of any solution involving power electronics converters is their generation of high-frequency pollution-namely, conducted and radiated noise in the 100 kHz to 100 MHz range-which can have an adverse effect on the operation of surrounding electronic equipment. Solutions to this problem are also offered in this paper     

电力电子系统集成的关键技术

本文综述电力电子系统集成的三项关键技术：改进的功率集成电路、功率变换器的高频数字控制和地磁芯变压器，包括设计考虑和特性。     

Device reliability and robust power converter development

This paper describes a top-down approach to reliability investigation of power electronic systems used in terrestrial and space applications. Results obtained from several case studies are presented that describe in detail both short-term and field failures of high-power DC−DC and AC−DC converters and the causes there-in. A systematic approach is presented that can be used to correlate field failures of power converters to residual defects and contaminants left in the semiconductor power switch, packaging and thermal management. Techniques and strategies that need to be applied in developing robust power converters for the next millennium are also outlined.     

An innovative technique for packaging power electronic buildingblocks using metal posts interconnected parallel plate structures

Power electronics building blocks (PEBBs) are envisioned as integrated power modules consisting of power semiconductor devices, power integrated circuits, sensors, and protection circuits for a wide range of power electronics applications, such as inverters for motor drives and converters for power processing equipment. At the Center for Power Electronics Systems, we developed a topology for a basic building block-a two-switch two-diode half-bridge converter in totem-pole configuration with built-in gate-driver and protection circuitry, fiber-optic receiver/transmitter interface, and soft-switching capability. Based on the topology, a series of prototype modules, with 600 V, 3.3 kW rating, were fabricated using an innovative packaging technique developed for the program-metal posts interconnected parallel plate structure (MPIPPS). This new packaging technique uses direct attachment of bulk copper, not wire-bonding of fine aluminum wires, for interconnecting power devices. Electrical performance data of the packaged devices show that an air-cooled 15 kW inverter, operating from 400 V dc bus with 20 kHz switching frequency can be constructed by integrating three prototype modules, which is almost double what could be achieved with commercially packaged devices of the same rating     

一种新型的封装发展趋势——圆片级封装

在军用电子元器件和民用消费类电路中,电子封装均起着举足轻重的地位。当今社会,电子技术日新月异,集成电路正向着超大规模、超高速、高密度、大功率、高精度、多功能的方向迅速发展,对集成电路的封装技术提出了愈来愈高的要求,使得新的封装形式不断涌现,新的封装技术层出不穷。文中介绍了一种新型的封装发展趋势——圆片级封装技术,主要详述了圆片级封装的概念、技术驱动力,列举了主要厂家圆片级封装技术的应用情况。     

Thermal management of power electronics modules packaged by a stacked-plate technique

The research presented in this paper is part of a multidisciplinary research program of the Center for Power Electronics Systems at Virginia Tech. The program supported by the Office of Naval Research focuses on the development of innovative technologies for packaging power electronics building blocks. The primary objective of this research is to improve package performance and reliability through thermal management, i.e., reducing device temperatures for a given power level. The task of thermal management involves considering trade-offs in the electrical design, package layout and geometry, materials selection and processing, manufacturing feasibility, and production cost. Based on the electrical design of a simple building block, samples of packaged modules, rated at 600 V and 3.3 kW, were fabricated using a stacked-plate technique, termed metal posts interconnected parallel plate structure (MPIPPS). The MPIPPS technique allows the power devices to be interconnected between two direct-bond copper substrates via the use of metal posts. Thermal modeling results on the MPIPPS packaged modules indicate that the new packaging technique offers a superior thermal management means for packaging power electronics modules.     

Capacitor loss analysis method for power electronics converters

A capacitor is a major component that contributes to reducing the reliability of high-power density power electronics converters. The lifetime and reliability of capacitors are strongly influenced by temperature. An accurate loss measurement method is necessary to estimate temperature rise. However, practical capacitor loss measurement systems used in power electronics converters have not yet been developed because capacitor loss data provided by the manufacturer is usually measured under sinusoidal excitation, which is different from actual excitations of electronics converters. In this study, a capacitor loss measurement system for power electronics converters is proposed. The proposed measurement system can be used for fast capacitor loss measurement with high accuracy in a real circuit and capacitor loss analysis for each switching period of power electronics converters. To verify the accuracy of the loss measurement, the measured loss value of a filter capacitor used in a pulse width modulated inverter is compared with the calculated value. The experimental results show good agreement with the calculated capacitor loss.     

Meniscus coating: a low-cost polymer deposition method for system-on-package (SOP) substrates

Meniscus coating is a low-cost deposition method that can be used to apply polymers in solution as thin films to the surface of electronics packaging substrates or flat panel displays. Most Roadmaps in electronics packaging project 6 to 8 /spl mu/m lines and spaces for next generation high density printed wiring board (PWB) substrates in the year 2006, which would require coating thickness of similar magnitudes for manufacturing fine lines with higher yield. Meniscus coating can be an enabling deposition method that can provide finer yet uniform coating on large area substrates which would translate to patterning finer copper traces, thereby increasing the wiring density. This paper reports preliminary results on coating thickness that can be achieved with photoresists, dielectrics, and solder masks which are the integral parts of the sequential build up multi-layer process for the system-on-package substrates.