EPE Association: EPE 2017 - DS3a: Power System Integration, Packaging & Thermal Management

EPE 2017 - DS3a: Power System Integration, Packaging & Thermal Management
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2017 ECCE Europe - Conference > EPE 2017 - Topic 01: Devices, Packaging and System Integration > EPE 2017 - DS3a: Power System Integration, Packaging & Thermal Management

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   3.3 kV SiC JBS Diode Configurable Rectifier Module
By Bassem MOUAWAD [View]
[Download]

Abstract: This paper presents the use of innovative high-voltage SiC diode technology in the development of a user configurable full-wave or half-wave rectifier bridge. The devices are of merged Junc- tion-Barrier-Schottky (JBS) type to enable for optimum performance even in the presence of current surges, as demanded by the application. To contain the cost of the proposed solution, their packaging relies on Insulated Metal Substrates (IMS), as opposed to conventional ceramic type substrates. The layout and module pin terminations are chosen to yield optimum electro- thermal and electro-magnetic performance in compatibility with a standard solder and wire- bond assembly process. Preliminary functional static characterization tests at different temper- atures are also presented.

   A Genetic Algorithm High Power Density Converter System Packing Method
By Lei LI [View]
[Download]

Abstract: Applications of power converters in electric cars and trains are demanding highly integrated systemswith reduced size and high reliability. To increase the power density, many advanced power convertersystems were developed utilizing the new wide-bandgap semiconductors or implementing highswitching frequency. However, literatures rarely demonstrate any method to optimize the layout of thepower converter system. In this paper, a genetic algorithm based method is proposed to design theconverter system packing. Detailed procedures are introduced. The method has been examined at athree-phase inverter, which verifies its feasibility and efficiency. It could be a major step to improvethe overall performance of the converter systems.

   A Low-Cost and High-Performance Thermal Interface Assembly between Printed Circuit Board and Heat-sink
By Nicolas DEGRENNE [View]
[Download]

Abstract: This paper presents a new and low-cost thermal interface assembly between a printed circuit board and a heat-sink that provides electric isolation on the whole surface, and thermal conduction where needed. The assembly relies on the association of an isolation and a spacer layer and a thermo-conductive gel. The bill of material is 8 times lower than a best in class thermal pad, and equivalent thermal resistance is 30\% lower.

   Evaluation of multi-void and drain metallization thickness effects on the electro thermal behavior of Si MOSFET under forward bias conditions
By Son Ha TRAN [View]
[Download]

Abstract: Single and multi-voids position effects will be highlighted from an electrothermal viewpoint. Complementary numerical investigations will show that these effects are strongly dependent on the properties of the backside metallization of the MOSFET chip. The methodology based on a coupled analysis of electrothermal modeling and experiments that led to these conclusions will be detailed.

   Experimental and Simulative Investigations on Stray Capacitances and Stray Inductances of Power Modules
By Georges ENGELMANN [View]
[Download]

Abstract: This paper presents different experimental methods for measuring parasitic capacitances and inductancesof direct copper bond (DBC) based power semiconductor modules. The found parasitics are comparedwith finite element simulations to evaluate their accuracy. A very good match of the simulated andmeasured stray capacitances is found.The parasitics, which are found via simulations and experiments, are integrated into a full equivalent circuitof the power module that can be used in SPICE simulations. The model is evaluated by a comparisonwith double pulse measurements for three examplary operating points. Satisfying simulation results ofthe developed model can be shown for the given operating points.

   High Power Compact Automotive IGBT Module with Planar Technology
By Yangang WANG [View]
[Download]

Abstract: Power IGBT module is one of the crucial factors limiting overall performance, reliability and cost of Hybrid and Electric Vehicles (HEV/EV). A clear booming market of automotive power module has been seen with the accelerated development of HEV/EV. Although a series of standard and custom automotive modules meeting most of customer requirements had been proposed recently, the continuous development is essential to keep up with the innovation steps of HEV/EV. In this work, a high power, high performance, compact automotive IGBT module with planar packaging technology is developed. The optimized design and process, as well as the electrical test are reported. The planar packaging leads to the double side cooling (DSC) capability which improves significantly the thermal, electrical performance and reliability. We are at the stage of qualifying the module by automotive standard and the releasing the product in a short period of time.

   Line reactor for parallel-interleaved high power inverters
By Ionut TRINTIS [View]
[Download]

Abstract: In this paper the line reactor design for parallel connection of high power inverters with interleavedcarriers is presented. Based on state of the art interleaving reactors configurations and based on highpower requirements, design iterations are performed to detect the implementation issues. The parasiticeffects are highlighted in finite element models and a new reluctance model is introduced. Experimentalresults are presented to support the findings from the simulations. Guidelines for future designs arehighlighted with focus on parameter stability and efficiency.

   Parallel and interleaved structures for diamond Schottky diodes.
By Gaëtan PEREZ [View]
[Download]

Abstract: In the recent years, diamond Schottky diodes with high Figures of Merit have been demonstrated. Static and dynamic characteristics of diamond Schottky diodes are presented in this paper. The diamond substrate is associated with silicon MOSFETs in a power switching cell, showing promising switching characteristics. However, even if these diodes show a high current density, the effective total current is limited by the small size of diamond diodes and substrate. To overcome this problem, one has to consider an association of such semiconductors to design power converters with high current ratings. Two converters integrating diamond Schottky diodes and silicon MOSFETs are presented here to understand the interactions of diodes inside the diamond substrate. This work can be used to determine the solutions to take advantage of this diamond semiconductor and to design full diamond converters in a coming future.

   Performance analysis of commercial MOSFET package in Class E converter operating at 2.56 MHz
By Unnikrishnan RAVEENDRAN NAIR [View]
[Download]

Abstract: Wide bandgap (WBG) power electronic devices realized using silicon carbide (SiC) and gallium nitride (GaN) are increasingly replacing their silicon (Si) counterparts in power electronics applications. The obvious advantages of these devices with their higher switching speeds, lower on state resistance and high temperature operation over Si devices have aided in the paradigm shift towards wide bandgap devices. The low gate charge requirements of SiC MOSFETs enables use of these devices in radio frequency (RF) converters using resonant topologies operating at MHz frequency range. The RF converters employed in various industrial applications are currently realized with vacuum tubes. Replacing vacuum tubes with solid state devices provides greater reliability. This requires power switches transferring high power at high switching speeds. Wide bandgap devices operating at these specifications are not commercially available and power modules have to be custom designed for these applications. This work demonstrates performance of various commercial MOSFET packages at frequency of 2.56 MHz. Commercial SiC MOSFETs in TO-247 and D2Pak packs are tested in Class E resonant converter operating at 2.56 MHz and compared with DE-275 Radio Frequency (RF) package performance under same operating conditions. Design considerations deduced from results can then be used in design of custom low voltage SiC RF modules and eventually can be used in the design of high voltage modules.

   Reliability Evaluation of Small-Sized Power Device with Low Thermal Resistance Structure
By Hiroaki ITO [View]
[Download]

Abstract: In this paper, we proposed a new small-sized power device. In the structure of the proposed device, the semiconductor chips are mounted vertically and both top and bottom surfaces of the device are cooled. By applying such a structure, it was shown that miniaturization can be realized without spoiling thermal characteristics.Furthermore, the thermal response characteristics of the proposed device under motor driving condition were evaluated. As the results, we confirmed that the proposed device has sufficient long term reliability.

   Substrate Choice and Thermal Optimization of a Half-bridge Power Module based on Chip Scale GaN HEMTs
By Javier ACUNA [View]
[Download]

Abstract: Packages of commercial Gallium-Nitride power semiconductors present increasingly small dimensionsto enable low parasitic inductance, increasing the heat flux density of the package and the challengesassociated with their thermal management. This paper compares between Printed Circuit Boards andDirect Copper Bonded as substrates for a Gallium Nitride based half-bridge from a thermal and reliabilitypoint of view. The layout for both substrates was numerically optimized and a compact thermal modelis proposed to compare both substrates. Measurement results confirm the modelling approach. Bothsubstrates were also analysed regarding their maximum operating temperature and expected thermalcycling capability.

   Switching Cell Design Optimization of SiC-based Power Modules for Current Source Inverter Applications
By Luis Gabriel ALVES RODRIGUES [View]
[Download]

Abstract: In this paper, a novel full-SiC power module suitable for three-phase Current Source Inverter (CSI) applications is presented. Based on state-of-the-art CSI modules, the problems associated with layout asymmetry are analyzed through electromagnetic (Finite Element Analysis software) and electrical simulations (Spice environment). Prototypes of the power module layouts are fabricated and parasitic measurements are carried out using a precision impedance analyzer.

   Switching current imbalance mitigation in power modules with parallel connected SiC MOSFETs
By Szymon BECZKOWSKI [View]
[Download]

Abstract: Multichip power modules use parallel connected chips to achieve high current rating. Due to a finite flexibility in a DBC layout, some electrical asymmetries will occur in the module. Parallel connected transistors will exhibit uneven static and dynamic current sharing due to these asymmetries. Especially important are the couplings between gate and power loops of individual transistors.Fast changing source currents cause gate voltage imbalances yielding uneven switching currents. Equalizing gate voltages seen by paralleled transistors, done by adjusting source bond wires,is proposed in this paper. Analysis is performed on an industry standard DBC layout using numerically extracted module parasitics. The method of tuning individual source inductances shows clear improvement in dynamic current balancing and prevents excessive current overshoot during transistors turn-on.

   Ultra-low inductive power module design with integrated common mode noise shielding
By Thomas HUBER [View]
[Download]

Abstract: A new ultra-low inductive 600 V / 200 A half-bridge power module, called LinkPack module, with integrated DC-link capacitors and common mode EMI shielding was realised. LinkPack module contains intentionally SiC-Mosfets, however it is also possible to equip Si-IGBTs and Si-diodes respectively SiC-diodes. This allows the realisation of full SiC-Mosfets modules, hybrid SiC modules and Si-IGBT / Si-diodes modules. The goal of this research was a significantly improved switching performance by reducing the power loop inductance in order to reduce switching losses and increasing efficiency. Integration of a common mode EMI shielding is a another very important aspect of the module design, which will be topic of this paper. LinkPack modules are intended to be driven at high switching frequencies of 20 kHz and more. Raising the switching frequency causes an increase of common mode noise spectrum level. So an effective EMI shielding is mandatory to avoid additional, large sized common mode filter devices. Measurements revealed an improved switching performance and less switching process oscillations. Turn-off speed is increased by factor 1.6, and simultaneously the common mode noise level can be significantly reduced up to 25 dBµV in a wide frequency range compared to corresponding conventional reference module design.

   Water-cooled On-Board Charger With Optimized Cooling Channel
By Sven BOLTE [View]
[Download]

Abstract: This contribution deals with the design of a water-cooled on-board charger for electric vehicles. The charger consists of two power stages: a bridgeless power factor correction boost rectifier and an isolating resonant converter. Though wide bandgap semiconductors with excellent reverse recovery behavior exist, the comparably high cost still advices the use of traditional silicon semiconductors. However, employing fast IGBTs in the PFC rectifier and trench MOSFETs in the resonant converter facilitate a reasonable maximum efficiency of about 96.5 \%. Besides efficiency, also high power density is obligatory. Therefore, water cooling is used for maximized heat transfer. In order to achieve low pressure loss, the profile of the cooling channel is optimized by means of computational fluid dynamics. The cooling concept enables a size reduction of the charger, where 1.4 kW/l power density was achieved.

EPE 2017 - DS3a: Power System Integration, Packaging & Thermal Management
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2017 ECCE Europe - Conference > EPE 2017 - Topic 01: Devices, Packaging and System Integration > EPE 2017 - DS3a: Power System Integration, Packaging & Thermal Management
	[return to parent folder]

	3.3 kV SiC JBS Diode Configurable Rectifier Module By Bassem MOUAWAD	[View] [Download]
Abstract: This paper presents the use of innovative high-voltage SiC diode technology in the development of a user configurable full-wave or half-wave rectifier bridge. The devices are of merged Junc- tion-Barrier-Schottky (JBS) type to enable for optimum performance even in the presence of current surges, as demanded by the application. To contain the cost of the proposed solution, their packaging relies on Insulated Metal Substrates (IMS), as opposed to conventional ceramic type substrates. The layout and module pin terminations are chosen to yield optimum electro- thermal and electro-magnetic performance in compatibility with a standard solder and wire- bond assembly process. Preliminary functional static characterization tests at different temper- atures are also presented.

	A Genetic Algorithm High Power Density Converter System Packing Method By Lei LI	[View] [Download]
Abstract: Applications of power converters in electric cars and trains are demanding highly integrated systemswith reduced size and high reliability. To increase the power density, many advanced power convertersystems were developed utilizing the new wide-bandgap semiconductors or implementing highswitching frequency. However, literatures rarely demonstrate any method to optimize the layout of thepower converter system. In this paper, a genetic algorithm based method is proposed to design theconverter system packing. Detailed procedures are introduced. The method has been examined at athree-phase inverter, which verifies its feasibility and efficiency. It could be a major step to improvethe overall performance of the converter systems.

	A Low-Cost and High-Performance Thermal Interface Assembly between Printed Circuit Board and Heat-sink By Nicolas DEGRENNE	[View] [Download]
Abstract: This paper presents a new and low-cost thermal interface assembly between a printed circuit board and a heat-sink that provides electric isolation on the whole surface, and thermal conduction where needed. The assembly relies on the association of an isolation and a spacer layer and a thermo-conductive gel. The bill of material is 8 times lower than a best in class thermal pad, and equivalent thermal resistance is 30\% lower.

	Evaluation of multi-void and drain metallization thickness effects on the electro thermal behavior of Si MOSFET under forward bias conditions By Son Ha TRAN	[View] [Download]
Abstract: Single and multi-voids position effects will be highlighted from an electrothermal viewpoint. Complementary numerical investigations will show that these effects are strongly dependent on the properties of the backside metallization of the MOSFET chip. The methodology based on a coupled analysis of electrothermal modeling and experiments that led to these conclusions will be detailed.

	Experimental and Simulative Investigations on Stray Capacitances and Stray Inductances of Power Modules By Georges ENGELMANN	[View] [Download]
Abstract: This paper presents different experimental methods for measuring parasitic capacitances and inductancesof direct copper bond (DBC) based power semiconductor modules. The found parasitics are comparedwith finite element simulations to evaluate their accuracy. A very good match of the simulated andmeasured stray capacitances is found.The parasitics, which are found via simulations and experiments, are integrated into a full equivalent circuitof the power module that can be used in SPICE simulations. The model is evaluated by a comparisonwith double pulse measurements for three examplary operating points. Satisfying simulation results ofthe developed model can be shown for the given operating points.

	High Power Compact Automotive IGBT Module with Planar Technology By Yangang WANG	[View] [Download]
Abstract: Power IGBT module is one of the crucial factors limiting overall performance, reliability and cost of Hybrid and Electric Vehicles (HEV/EV). A clear booming market of automotive power module has been seen with the accelerated development of HEV/EV. Although a series of standard and custom automotive modules meeting most of customer requirements had been proposed recently, the continuous development is essential to keep up with the innovation steps of HEV/EV. In this work, a high power, high performance, compact automotive IGBT module with planar packaging technology is developed. The optimized design and process, as well as the electrical test are reported. The planar packaging leads to the double side cooling (DSC) capability which improves significantly the thermal, electrical performance and reliability. We are at the stage of qualifying the module by automotive standard and the releasing the product in a short period of time.

	Line reactor for parallel-interleaved high power inverters By Ionut TRINTIS	[View] [Download]
Abstract: In this paper the line reactor design for parallel connection of high power inverters with interleavedcarriers is presented. Based on state of the art interleaving reactors configurations and based on highpower requirements, design iterations are performed to detect the implementation issues. The parasiticeffects are highlighted in finite element models and a new reluctance model is introduced. Experimentalresults are presented to support the findings from the simulations. Guidelines for future designs arehighlighted with focus on parameter stability and efficiency.

	Parallel and interleaved structures for diamond Schottky diodes. By Gaëtan PEREZ	[View] [Download]
Abstract: In the recent years, diamond Schottky diodes with high Figures of Merit have been demonstrated. Static and dynamic characteristics of diamond Schottky diodes are presented in this paper. The diamond substrate is associated with silicon MOSFETs in a power switching cell, showing promising switching characteristics. However, even if these diodes show a high current density, the effective total current is limited by the small size of diamond diodes and substrate. To overcome this problem, one has to consider an association of such semiconductors to design power converters with high current ratings. Two converters integrating diamond Schottky diodes and silicon MOSFETs are presented here to understand the interactions of diodes inside the diamond substrate. This work can be used to determine the solutions to take advantage of this diamond semiconductor and to design full diamond converters in a coming future.

	Performance analysis of commercial MOSFET package in Class E converter operating at 2.56 MHz By Unnikrishnan RAVEENDRAN NAIR	[View] [Download]
Abstract: Wide bandgap (WBG) power electronic devices realized using silicon carbide (SiC) and gallium nitride (GaN) are increasingly replacing their silicon (Si) counterparts in power electronics applications. The obvious advantages of these devices with their higher switching speeds, lower on state resistance and high temperature operation over Si devices have aided in the paradigm shift towards wide bandgap devices. The low gate charge requirements of SiC MOSFETs enables use of these devices in radio frequency (RF) converters using resonant topologies operating at MHz frequency range. The RF converters employed in various industrial applications are currently realized with vacuum tubes. Replacing vacuum tubes with solid state devices provides greater reliability. This requires power switches transferring high power at high switching speeds. Wide bandgap devices operating at these specifications are not commercially available and power modules have to be custom designed for these applications. This work demonstrates performance of various commercial MOSFET packages at frequency of 2.56 MHz. Commercial SiC MOSFETs in TO-247 and D2Pak packs are tested in Class E resonant converter operating at 2.56 MHz and compared with DE-275 Radio Frequency (RF) package performance under same operating conditions. Design considerations deduced from results can then be used in design of custom low voltage SiC RF modules and eventually can be used in the design of high voltage modules.

	Reliability Evaluation of Small-Sized Power Device with Low Thermal Resistance Structure By Hiroaki ITO	[View] [Download]
Abstract: In this paper, we proposed a new small-sized power device. In the structure of the proposed device, the semiconductor chips are mounted vertically and both top and bottom surfaces of the device are cooled. By applying such a structure, it was shown that miniaturization can be realized without spoiling thermal characteristics.Furthermore, the thermal response characteristics of the proposed device under motor driving condition were evaluated. As the results, we confirmed that the proposed device has sufficient long term reliability.

	Substrate Choice and Thermal Optimization of a Half-bridge Power Module based on Chip Scale GaN HEMTs By Javier ACUNA	[View] [Download]
Abstract: Packages of commercial Gallium-Nitride power semiconductors present increasingly small dimensionsto enable low parasitic inductance, increasing the heat flux density of the package and the challengesassociated with their thermal management. This paper compares between Printed Circuit Boards andDirect Copper Bonded as substrates for a Gallium Nitride based half-bridge from a thermal and reliabilitypoint of view. The layout for both substrates was numerically optimized and a compact thermal modelis proposed to compare both substrates. Measurement results confirm the modelling approach. Bothsubstrates were also analysed regarding their maximum operating temperature and expected thermalcycling capability.

	Switching Cell Design Optimization of SiC-based Power Modules for Current Source Inverter Applications By Luis Gabriel ALVES RODRIGUES	[View] [Download]
Abstract: In this paper, a novel full-SiC power module suitable for three-phase Current Source Inverter (CSI) applications is presented. Based on state-of-the-art CSI modules, the problems associated with layout asymmetry are analyzed through electromagnetic (Finite Element Analysis software) and electrical simulations (Spice environment). Prototypes of the power module layouts are fabricated and parasitic measurements are carried out using a precision impedance analyzer.

	Switching current imbalance mitigation in power modules with parallel connected SiC MOSFETs By Szymon BECZKOWSKI	[View] [Download]
Abstract: Multichip power modules use parallel connected chips to achieve high current rating. Due to a finite flexibility in a DBC layout, some electrical asymmetries will occur in the module. Parallel connected transistors will exhibit uneven static and dynamic current sharing due to these asymmetries. Especially important are the couplings between gate and power loops of individual transistors.Fast changing source currents cause gate voltage imbalances yielding uneven switching currents. Equalizing gate voltages seen by paralleled transistors, done by adjusting source bond wires,is proposed in this paper. Analysis is performed on an industry standard DBC layout using numerically extracted module parasitics. The method of tuning individual source inductances shows clear improvement in dynamic current balancing and prevents excessive current overshoot during transistors turn-on.

	Ultra-low inductive power module design with integrated common mode noise shielding By Thomas HUBER	[View] [Download]
Abstract: A new ultra-low inductive 600 V / 200 A half-bridge power module, called LinkPack module, with integrated DC-link capacitors and common mode EMI shielding was realised. LinkPack module contains intentionally SiC-Mosfets, however it is also possible to equip Si-IGBTs and Si-diodes respectively SiC-diodes. This allows the realisation of full SiC-Mosfets modules, hybrid SiC modules and Si-IGBT / Si-diodes modules. The goal of this research was a significantly improved switching performance by reducing the power loop inductance in order to reduce switching losses and increasing efficiency. Integration of a common mode EMI shielding is a another very important aspect of the module design, which will be topic of this paper. LinkPack modules are intended to be driven at high switching frequencies of 20 kHz and more. Raising the switching frequency causes an increase of common mode noise spectrum level. So an effective EMI shielding is mandatory to avoid additional, large sized common mode filter devices. Measurements revealed an improved switching performance and less switching process oscillations. Turn-off speed is increased by factor 1.6, and simultaneously the common mode noise level can be significantly reduced up to 25 dBµV in a wide frequency range compared to corresponding conventional reference module design.

	Water-cooled On-Board Charger With Optimized Cooling Channel By Sven BOLTE	[View] [Download]
Abstract: This contribution deals with the design of a water-cooled on-board charger for electric vehicles. The charger consists of two power stages: a bridgeless power factor correction boost rectifier and an isolating resonant converter. Though wide bandgap semiconductors with excellent reverse recovery behavior exist, the comparably high cost still advices the use of traditional silicon semiconductors. However, employing fast IGBTs in the PFC rectifier and trench MOSFETs in the resonant converter facilitate a reasonable maximum efficiency of about 96.5 \%. Besides efficiency, also high power density is obligatory. Therefore, water cooling is used for maximized heat transfer. In order to achieve low pressure loss, the profile of the cooling channel is optimized by means of computational fluid dynamics. The cooling concept enables a size reduction of the charger, where 1.4 kW/l power density was achieved.