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M.A. Zimmermann

Bio: M.A. Zimmermann is an academic researcher from Rockwell Collins. The author has contributed to research in topics: Reliability (semiconductor). The author has an hindex of 1, co-authored 1 publications receiving 9 citations.

Papers
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Proceedings ArticleDOI
27 Sep 2004
TL;DR: In this paper, a high-yield design approach for surface mount power packages utilizing PWB thermal vias, elastomeric material and heatsinks was established to meet cooling and producibility requirements.
Abstract: Establish a high-yield design approach for surface mount power packages utilizing PWB thermal vias, elastomeric material and heatsinks. A feasibility study proved that the thermal via concept could be implemented to meet cooling and producibility requirements. Reliability testing demonstrated negligible thermal path degradation for a 15-year life equivalent in airborne environment.

10 citations


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Journal ArticleDOI
TL;DR: In this article, an axisymmetric thermal resistance model is developed for PCB thermal pads where the heat conduction, convection, and radiation all exist; due to the interdependence between the conductive/radiative heat transfer coefficients and the board temperatures, an algorithm is proposed to fast obtain the board-ambient thermal resistance and to predict the semiconductor junction temperature.
Abstract: Miniature power semiconductor devices mounted on printed circuit boards (PCBs) are normally cooled by means of PCB vias, copper pads, and/or heatsinks. Various reference PCB thermal designs have been provided by semiconductor manufacturers and researchers. However, the recommendations are not optimal, and there are some discrepancies among them, which may confuse electrical engineers. This paper aims to develop analytical thermal resistance models for PCB vias and pads, and further to obtain the optimal design for thermal resistance minimization. First, the PCB via array is thermally modeled in terms of multiple design parameters. A systematic parametric analysis leads to an optimal trajectory for the via diameter at different PCB specifications. Then, an axisymmetric thermal resistance model is developed for PCB thermal pads where the heat conduction, convection, and radiation all exist; due to the interdependence between the conductive/radiative heat transfer coefficients and the board temperatures, an algorithm is proposed to fast obtain the board-ambient thermal resistance and to predict the semiconductor junction temperature. Finally, the proposed thermal models and design optimization algorithms are verified by computational fluid dynamics simulations and experimental measurements.

33 citations

Journal ArticleDOI
TL;DR: This article presents a single-stage interleaved LLC resonant converter of 3.6 kW and shows that phase-shift operation and asymmetrical duty-cycle modulation can be utilized for power balancing for full-bridge and half-bridge configurations, respectively, such that a much smaller output capacitor can be employed.
Abstract: Automotive on-board dc–dc converters are required to operate over a wide input and output voltage range depending on the state of charge of the input and the output battery. Conventionally, the unidirectional power transfer between these batteries is enabled by a two-stage converter concept. A first-stage nonisolated dc–dc converter regulates the input voltage of the galvanically isolated second-stage dc–dc converter such that the second-stage converter operates in its optimum operating point. This article presents a single-stage interleaved LLC resonant converter of 3.6 kW for this purpose. While LLC converters are usually not suitable to cover such a wide voltage range (the input voltage between 240 and 420 V and the output voltage between 8 and 16 V), this LLC converter is operated in a full-bridge mode for large gains and in a half-bridge mode for low gains. For intermediate gains and loads, the LLC employs the phase-shift mode. To operate the interleaved LLC s at equal switching frequencies enabling output current ripple cancellation to reduce the output capacitor, again, the phase-shift mode is utilized to balance the power transfer during the full-bridge mode while the asymmetrical duty-cycle mode is proposed for power balancing during the half-bridge mode. This article analyzes the converter design for these modes of operation and provides a comprehensive design procedure allowing the designer to simultaneously analyze all stress values for various resonant tank designs. A 3.6-kW prototype employing Si superjunction MOSFETs achieves a power density of 2.1 kW/L. The maximum efficiency reaches 96.5%, while for most operating points, it is kept well above 90%. The experimental measurement results validate the analysis and show that phase-shift operation and asymmetrical duty-cycle modulation can be utilized for power balancing for full-bridge and half-bridge configurations, respectively, such that a much smaller output capacitor can be employed.

27 citations

Proceedings ArticleDOI
17 Mar 2013
TL;DR: In this paper, a thorough literature review of the design and analysis of thermal vias in PCBs for thermal management of devices in power electronics converters is presented, based on the conclusions drawn from the available literature and practical manufacturing guidelines, four different via patterns for a single power device are selected and their thermal performances are studied.
Abstract: One important challenge in power electronics design is removing the heat cost effectively from the power devices. A thermal via is a small diameter hole plated with copper and is used to transfer the heat from one side of the printed circuit board (PCB) to the other side. In this paper, a thorough literature review of the design and analysis of thermal vias in PCBs for thermal management of devices in power electronics converters are presented. Key advantages of using PCB's for thermal management are also presented. Based on the conclusions drawn from the available literature and practical manufacturing guidelines, four different via patterns for a single power device are selected and their thermal performances are studied. Each of the four via patterns is laid out multiple times on the same PCB. A power component in a D2PAK is soldered to each of the patterns. The PCB is attached to a liquid cooled cold plate. The devices are powered up and a thermal imaging camera is used to record the temperature of the device. The experimental results presented closely matches with the theoretical prediction and helps in identifying the most efficient thermal via pattern.

19 citations

Proceedings ArticleDOI
28 Oct 2013
TL;DR: In this article, a thorough literature review of the design and analysis of thermal vias in PCBs for thermal management of power electronics devices is presented based on the results from available literature and practical manufacturing guidelines, four different via patterns for single power devices are selected.
Abstract: A daunting challenge in packaging design for power electronics products is removing the heat from the power devices in a cost effective manner In this paper, a thorough literature review of the design and analysis of thermal vias in PCBs for thermal management of power electronics devices are presented Based on the results from the available literature and practical manufacturing guidelines, four different via patterns for single power devices are selected Each of the four via patterns is laid out multiple times with their via holes are filled with a filler material and their performance are compared to non-filled thermal vias One dimensional analysis is performed to characterize the thermal performance of the thermal via patterns The experimental results presented closely matches the theoretical prediction to identify the most efficient thermal via pattern

17 citations

Proceedings ArticleDOI
16 Mar 2014
TL;DR: In this article, a detailed comparison of the properties of various off-the-shelf available TIMs to be specifically used between PCB with thermal vias and heat sink is presented, and experimental results are presented to determine the thermal performance of various TIMs.
Abstract: One important challenge in power electronics design is removing the heat cost effectively from the power devices mounted on thermal vias on a printed circuited board (PCB). Thermal vias is a cluster of small diameter hole plated with copper and is used to transfer the heat from one side of the PCB where the power device is soldered to the other side which is generally mounted on a heat sink using a thermal interface material (TIM). To minimize the contact resistance and provide electrical insulation between the PCB and heat sink, TIMs are used to fill the air gaps and are an essential part of an assembly when solid surfaces are attached together. This paper presents a detailed comparison of the properties of various off-the-shelf available TIMs to be specifically used between PCB with thermal vias and heat sink. Experimental results are presented to determine the thermal performance of various TIMs.

12 citations