Presents a collection of slides covering the following topics: commercial power electronics; power sandwich concept for manufacturability; inductors; capacitors; SMT automated manufacturing; pick and place; soldering; multilayer thermal management concept; temperature distribution analysis; natural convection cooling; and forced convection cooling.@en

This paper presents thermal management considerations for a multilayer stacked converter construction technology Power Sandwich. The multilayer converters are built using novel x-dim components that have uniform height and double-sided SMT terminals. The SMT terminals of the components are soldered to two substrates and together with the substrate metallisation form copper-conductors reinforced multilayer assembly. Such structure has enhanced thermal performance as is shown in the paper. The concept enable more uniform distribution in the systems with non-uniform power loss distribution as proven by CFD simulations and experimental demonstrators, thus simplifying the design procedure of power sandwich converters. Analytical thermal models for forced and natural convection heat transfer from multilayer converters are developed and experimentally validated. The thermal design procedures and models are illustrated on constructed high power density sandwich demonstrators: 150W HID lamp electronic ballast and 2.2kW inverter for motor drive.@en

This paper investigates the switching behaviour of normally-off SiC JFETs in an inverter for a motor drive. The parasitic ringing caused by different parasitic effects is analysed. Two different methods, the use of an RC snubber and the use of a ferrite bead, are proposed for dampening the parasitic oscillations. It is found that applying a ferrite bead not only dampens the parasitic oscillations but also results in significantly lower switching losses. Furthermore, it is shown that the capacitive coupling between SiC devices and heat sinks significantly deteriorates the JFETs' switching performance. The effect of two substrates, an IMS and a PCB, on the capacitive coupling is investigated. A method in which the use of two separate heat sinks minimises the capacitive coupling thus exploiting the full potential of fast SiC JFETs is proposed.@en

This work presents an implementation of a compact and highly efficient 2.2kW industrial drive using the Power Sandwich layered construction, x-dimension (x-dim) passive components and wide-band gap SiC semiconductors (JFETs and diodes). X-dim SMT components that have uniform height and enhanced thermal properties are stacked between planar substrates to achieve high power density and better thermal performance of industrial drive. The use of wide band gap SiC semiconductors results in an industrial drive efficiency increase of around 3% compared to that of Si-based counterpart. It is found that the parasitic coupling between SiC semiconductors and heat sinks significantly deteriorates the JFET's switching performance. The thermal management concept for industrial drive, in which two separate heat sinks minimises the capacitive coupling effect thus exploiting the full potential of fast SiC JFETs is proposed. The layered 3-D construction and lower power loss enabled by SiC semiconductors allows for reduced thermal management effort and consequently increased power density. The 2.2kW SiC-based industrial drive has the power density of 3.8kW/l, system efficiency of 98.4% and operates at the temperatures below 50°C without typical heavy and/or complex heat sinks.@en

This paper proposes a comprehensive EMI common-mode (CM) filter design procedure to suppress conducted EMI in silicon carbide (SiC) JFETs based inverter-fed motor drive systems. The first part of this paper is focusing on analyzing the EMC issue arisen from the newly generated power semiconductor device - SiC JFET, where the switching dynamics of SiC JFET and Si IGBT with the same power flowing level are compared. Then the second part towards EMI suppression for the inverter prototype. A comprehensive EMI CM filter design procedure is proposed. The proposed CM equivalent circuit model is able to evaluate the filter insertion loss gains over the whole conducted EMI frequency range, thereby different filter topologies can be compared and optimally selected. The performed experiments form the guideline that exhibits the process how the generated conducted EMI from the built inverter prototype is successfully suppressed to comply with the IEC61800-3 standard step by step.@en

This paper presents a novel power electronics construction technology for surface mount technology (SMT) automated manufacturing of power converters- Power Sandwich. The Power Sandwich manufacturing method employs new x-dimension components, having the same height (x) and double sided SMT electrical terminations. The components are stacked between planar substrates and can be soldered on both, top and bottom sides using the multilayer Power Sandwich assembly process. The process is compatible with standard SMT assembly line with some alternations. By arranging the components in different stack layers an increase in power density and better heat removal from the systems can be achieved. Power Sandwich is an enabling integration technology for achieving both SMT automated construction and high power densities of power electronics converters.@en

The paper presents the design and construction of new SMT power inductors that allow for high components packaging density and automated manufacturing of power converters. The inductors are double sided SMDs with a uniform profile (14mm), reduced packaging (i.e. no coil former) and enhanced thermal properties. The inductor is implemented with drum and shield magnetic core parts. The thermal behaviour of the inductors is improved by employing heat extractors and filling the air gaps by thermal glue. Several inductor samples for different power levels and applications have been manufactured. The electromagnetic and thermal designs of the inductors are given in details. Because of larger air gaps the inductance value is calculated with the aid of FEM to include fringing field effects. The simulated inductance value match measured inductance value within ±3%. New inductors have reduced size, enable effective heat removal and are necessary building blocks in automated manufacturing of power converters.@en

This paper introduces a new concept for surface mount technology (SMT) automated manufacturing of power converters - PCB power sandwich. The power sandwich manufacturing method employs new x-dimension (x-dim) components, having the same height (x) and double sided SMT electrical terminations. The components are stacked between planar substrates and soldered on both, top and bottom sides using the multilayer power sandwich assembly process. By arranging the components in different stack layers an increase in power density, better heat removal and improved EMI performance of power converters can be achieved. New x-dim components enable fully SMT automated power converters manufacturing with short production time and low assembly cost.@en

The paper introduces new x-dimension (x-dim) components that allow for high components packaging density and automated manufacturing of power converters. The x-dim components are double sided SMT passives, having uniform height (x) and enhanced thermal properties. With stacked converter construction and the x-dim components soldered to two sides, the heat removal from the systems can be significantly improved. This publication presents various methods to manufacture thermally enhanced x-dim components. The thermal behaviour of x-dim components is improved by integrating heat extractors, removing packaging materials and filling the air gaps by potting compounds. In the stacked construction, thermal enhancement of one component improves heat removal from other components, placed in adjacent stack layers. Thermal performance of x-dim components in both standard and stacked converter constructions is evaluated by FEM and analytical simulations. New x-dim components employed in stacked construction play a key role in overcoming current power density limits.@en

Abstract Current passive components construction technologies and power converters manufacturing methods are the main barriers limiting the power density improvement. In this paper a new PCB system integration concept for power converters construction - power sandwich, that allows for a high density packaging, effective thermal management and automated manufacturing is introduced. In the Power sandwich integration concept new passive components, x-dimension components, having the same height (x) and double sided electrical terminations are stacked between planar substrates and soldered on two sides. Depending on the number of stack layers (x-layers) and the components loss density, various arrangements in the power sandwich converter is possible. A power sandwich demonstrator, 70 W flyback converter, is designed and implemented using modified standard components representing the prototype of x-dimension components. The spatial and thermal designs are discussed in detail and the experimental results of the first power sandwich demonstrator are shown.@en