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Design and Experimental Validation of a Wire-Bond-Less 10-kV SiC MOSFET Power Module (2019)
Journal Article
DiMarino, C., Mouawad, B., Johnson, C. M., Wang, M., Tan, Y., Lu, G., …Burgos, R. (2020). Design and Experimental Validation of a Wire-Bond-Less 10-kV SiC MOSFET Power Module. IEEE Journal of Emerging and Selected Topics in Power Electronics, 8(1), 381-394. https://doi.org/10.1109/jestpe.2019.2944138

Wide bandgap (WBG) power devices with voltage ratings exceeding 10 kV have the potential to revolutionize medium-and high-voltage systems due to their high-speed switching and lower ON-state losses. However, the present power module packages are limi... Read More about Design and Experimental Validation of a Wire-Bond-Less 10-kV SiC MOSFET Power Module.

Three‐dimensional damage morphologies of thermomechanically deformed sintered nanosilver die attachments for power electronics modules (2019)
Journal Article
Agyakwa, P., Dai, J., Li, J., Mouawad, B., Yang, L., Corfield, M., & Johnson, C. (2019). Three‐dimensional damage morphologies of thermomechanically deformed sintered nanosilver die attachments for power electronics modules. Journal of Microscopy, 277(3), 140-153. https://doi.org/10.1111/jmi.12803

© 2019 The Authors. Journal of Microscopy published by John Wiley & Sons Ltd on behalf of Royal Microscopical Society. A time-lapse study of thermomechanical fatigue damage has been undertaken using three-dimensional X-ray computer tomography. Morp... Read More about Three‐dimensional damage morphologies of thermomechanically deformed sintered nanosilver die attachments for power electronics modules.

Packaging technology for a highly integrated 10kV SiC MOSFET module (2018)
Presentation / Conference
Mouawad, B., Di Marino, C., Li, J., Skuriat, R., & Johnson, M. (2018, August). Packaging technology for a highly integrated 10kV SiC MOSFET module. Paper presented at 14th International Seminar on Power Semiconductors (ISPS 2018), Prague, Czech Republic

High-voltage SiC devices offer an attractive combination of fast switching and low losses, giving application users unprecedented levels of flexibility in choice of topology and control strategy for medium- and high-voltage power conversion. However,... Read More about Packaging technology for a highly integrated 10kV SiC MOSFET module.

Development of a highly integrated 10 kV SiC MOSFET power module with a direct jet impingement cooling system (2018)
Conference Proceeding
Mouawad, B., Skuriat, R., Li, J., Johnson, C. M., & DiMarino, C. (2018). Development of a highly integrated 10 kV SiC MOSFET power module with a direct jet impingement cooling system. In 2018 IEEE 30th International Symposium on Power Semiconductor Devices and ICs (ISPSD). https://doi.org/10.1109/ispsd.2018.8393651

This paper presents a novel, highly integrated packaging design for Wolfspeed’s 10 kV SiC MOSFETs. These devices offer faster switching performance and lower losses than silicon devices. However, it has been shown that the package can have profound i... Read More about Development of a highly integrated 10 kV SiC MOSFET power module with a direct jet impingement cooling system.

Cost effective direct-substrate jet impingement cooling concept for power application (2018)
Conference Proceeding
Mouawad, B., Abebe, R., Skuriat, R., Li, J., De Lillo, L., Empringham, L., …Haynes, G. (2018). Cost effective direct-substrate jet impingement cooling concept for power application. In PCIM Europe 2018; International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management

Direct substrate jet impingement cooling can eliminate the use of the baseplate and significantly reduce the weight and volume of conventional thermal management solutions. This work demonstrates a cost-effective manufacturing approach based on print... Read More about Cost effective direct-substrate jet impingement cooling concept for power application.

A wire-bond-less 10 KV SiC MOSFET power module with reduced common-mode noise and electric field (2018)
Conference Proceeding
DiMarino, C., Mouawad, B., Skuriat, R., Li, K., Xu, Y., Johnson, C., …Burgos, R. (2018). A wire-bond-less 10 KV SiC MOSFET power module with reduced common-mode noise and electric field. In PCIM Europe 2018; International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management

While wide-bandgap devices offer many benefits, they also bring new challenges for designers. In particular, the new 10 kV silicon carbide (SiC) MOSFETs can switch higher voltages faster and with lower losses than silicon devices while also being sma... Read More about A wire-bond-less 10 KV SiC MOSFET power module with reduced common-mode noise and electric field.

Novel silicon carbide integrated power module for EV application (2018)
Conference Proceeding
Mouawad, B., Espina, J., Li, J., Empringham, L., & Johnson, C. M. (2018). Novel silicon carbide integrated power module for EV application. In IEEE Workshop on Wide Bandgap Power Devices and Applications in Asia (WiPDA Asia 2018), At Xi'an, Shaanxi

The successful penetration of Electric Vehicles (EVs) into the global automotive markets requires the developments of cost effective, high performance and high integration power electronic systems. The present work is concerned with the structural in... Read More about Novel silicon carbide integrated power module for EV application.

Next generation integrated drive: a novel thermal and electrical integration technique for high power density converters used in automotive drive systems (2018)
Conference Proceeding
Ahmadi, B., Espina, J., De Lillo, L., Abebe, R., Empringham, L., & Johnson, C. M. (2018). Next generation integrated drive: a novel thermal and electrical integration technique for high power density converters used in automotive drive systems.

In this paper, an innovative method of electro-thermal integration of a drive system is presented. Important challenges of this integration consist of, firstly coupled thermal design of switching power modules and PM electric motor and secondly integ... Read More about Next generation integrated drive: a novel thermal and electrical integration technique for high power density converters used in automotive drive systems.

Comparative Thermal and Structural Characterization of Sintered Nano-Silver and High-Lead Solder Die Attachments During Power Cycling (2018)
Journal Article
Dai, J., Li, J., Agyakwa, P., Corfield, M., & Johnson, C. M. (2018). Comparative Thermal and Structural Characterization of Sintered Nano-Silver and High-Lead Solder Die Attachments During Power Cycling. IEEE Transactions on Device and Materials Reliability, 18(2), 256-265. https://doi.org/10.1109/TDMR.2018.2825386

13.5 mm × 13.5 mm sintered nano-silver attachments for power devices onto AlN substrates were prepared at 250 ºC and a pressure of 10MPa for 5 minutes and compared with Pb5Sn solder joint die attachments under constant current power cycling with an i... Read More about Comparative Thermal and Structural Characterization of Sintered Nano-Silver and High-Lead Solder Die Attachments During Power Cycling.

Comparison of thermal and reliability performance between a SiC MOSFET module with embedded decoupling capacitors and commercial Si IGBT power modules (2018)
Conference Proceeding
Yang, L., Agyakwa, P., Corfield, M., Johnson, M., Harris, A., Packwood, M., & Paciura, K. (2018). Comparison of thermal and reliability performance between a SiC MOSFET module with embedded decoupling capacitors and commercial Si IGBT power modules.

This paper characterizes thermal and reliability performance of a SiC MOSFET power module with embedded decoupling capacitors and without anti-parallel diodes. Active and passive temperature cycling, supported by transient thermal impedance character... Read More about Comparison of thermal and reliability performance between a SiC MOSFET module with embedded decoupling capacitors and commercial Si IGBT power modules.

Comparison of power cycling reliability of flexible PCB interconnect smaller/thinner and larger/thicker power devices with topside Sn-3.5Ag solder joints (2018)
Journal Article
Li, J., Dai, J., & Johnson, C. M. (2018). Comparison of power cycling reliability of flexible PCB interconnect smaller/thinner and larger/thicker power devices with topside Sn-3.5Ag solder joints. Microelectronics Reliability, 84, 55-65. https://doi.org/10.1016/j.microrel.2018.03.013

The power cycling reliability of flexible printed circuit board (PCB) interconnect smaller/thinner (ST) 9.5 mm × 5.5 mm × 0.07 mm and larger/thicker (LT) 13.5 mm × 13.5 mm × 0.5 mm single Si diode samples have been studied. With the assumption of cre... Read More about Comparison of power cycling reliability of flexible PCB interconnect smaller/thinner and larger/thicker power devices with topside Sn-3.5Ag solder joints.

Electrical Performance and Reliability Characterization of a SiC MOSFET Power Module With Embedded Decoupling Capacitors (2018)
Journal Article
O Brien, J., Yang, L., Li, K., Dai, J., Corfield, M., Harris, A., …Johnson, C. M. (2018). Electrical Performance and Reliability Characterization of a SiC MOSFET Power Module With Embedded Decoupling Capacitors. IEEE Transactions on Power Electronics, 33(12), 10594-10601. https://doi.org/10.1109/TPEL.2018.2809923

Integration of decoupling capacitors in SiC MOSFET modules is an advanced solution to mitigate the effect of parasitic inductance induced by module assembly interconnects. In this paper, the switching transient behavior is reported for a 1.2kV SiC MO... Read More about Electrical Performance and Reliability Characterization of a SiC MOSFET Power Module With Embedded Decoupling Capacitors.

Improved Reliability of Planar Power Interconnect With Ceramic-Based Structure (2017)
Journal Article
Zhang, H., Li, J., Dai, J., Corfield, M., Liu, X., Liu, Y., …Johnson, C. M. (2018). Improved Reliability of Planar Power Interconnect With Ceramic-Based Structure. IEEE Journal of Emerging and Selected Topics in Power Electronics, 6(1), 175-187. https://doi.org/10.1109/jestpe.2017.2758901

This paper proposes an advanced Si3N4 ceramic-based structure with through vias designed and filled with brazing alloy as a reliable interconnect solution in planar power modules. Finite element (FE) modeling and simulation were first used to predict... Read More about Improved Reliability of Planar Power Interconnect With Ceramic-Based Structure.

A study on probability of distribution loads based on expectation maximization algorithm (2017)
Conference Proceeding
Ganjavi, A., Christopher, E., Johnson, C. M., & Clare, J. (2017). A study on probability of distribution loads based on expectation maximization algorithm. In IEEE Power and Energy Society Innovative Smart Grid Technologies Conference, ISGT 2017 (1-5). https://doi.org/10.1109/ISGT.2017.8086037

In a distribution power network, the load model has no certain pattern or predicted behaviour due to large range of data and changes in energy consumption for end-user consumers. Thus, a powerful analysis based on probabilistic structure is required.... Read More about A study on probability of distribution loads based on expectation maximization algorithm.

Time-Efficient Sintering Processes to Attach Power Devices Using Nanosilver Dry Film (2017)
Journal Article
Dai, J., Li, J., Agyakwa, P., & Johnson, C. M. (2017). Time-Efficient Sintering Processes to Attach Power Devices Using Nanosilver Dry Film. Journal of Microelectronics and Electronic Packaging, 14(4), 140-149. https://doi.org/10.4071/imaps.521776

Pressure-assisted sintering processes to attach power devices using wet nanosilver pastes with time scales of minutes to a few hours have been widely reported. This paper presents our work on time-efficient sintering, using nanosilver dry film and an... Read More about Time-Efficient Sintering Processes to Attach Power Devices Using Nanosilver Dry Film.

Characterisation and modelling of gallium nitride power semiconductor devices dynamic on-state resistance (2017)
Journal Article
Li, K., Evans, P., & Johnson, M. (2018). Characterisation and modelling of gallium nitride power semiconductor devices dynamic on-state resistance. IEEE Transactions on Power Electronics, 33(6), 5262 - 5273. https://doi.org/10.1109/TPEL.2017.2730260

GaN-HEMTs suffer from trapping effects which increases device ON-state resistance (RDS(on)) above its theoretical value. This increase is a function of the applied DC bias when the device is in its OFF state, and the time which the device is biased f... Read More about Characterisation and modelling of gallium nitride power semiconductor devices dynamic on-state resistance.

A new analysis for finding the optimum power rating of low voltage distribution power electronics based on statistics and probabilities (2017)
Conference Proceeding
Ganjavi, A., Christopher, E., Johnson, C. M., & Clare, J. C. (2017). A new analysis for finding the optimum power rating of low voltage distribution power electronics based on statistics and probabilities.

The continuing trend toward heavier load and high penetration of Distribution Generation (DG) units in low voltage rural distribution feeders requires power electronic-based solution alternatives for voltage regulation purposes. The design of power e... Read More about A new analysis for finding the optimum power rating of low voltage distribution power electronics based on statistics and probabilities.

Design and development of a high-density, high-speed 10 kV SiC MOSFET module (2017)
Conference Proceeding
Di Marino, C., Boroyevich, D., Burgos, R., Johnson, C. M., & Lu, G. (2017). Design and development of a high-density, high-speed 10 kV SiC MOSFET module.

High-density packaging of fast-switching power semiconductors typically requires low parasitic inductance, high heat extraction, and high thermo-mechanical reliability. High-density packaging of high-voltage power semiconductors, such as 10 kV SiC MO... Read More about Design and development of a high-density, high-speed 10 kV SiC MOSFET module.

SiC/GaN power semiconductor devices: a theoretical comparison and experimental evaluation under different switching conditions (2017)
Journal Article
Li, K., Evans, P., & Johnson, M. (in press). SiC/GaN power semiconductor devices: a theoretical comparison and experimental evaluation under different switching conditions. IET Electrical Systems in Transportation, https://doi.org/10.1049/iet-est.2017.0022

The conduction and switching losses of SiC and GaN power transistors are compared in this paper. Voltage rating of commercial GaN power transistors is less than 650V while that of SiC power transistors is less than 1200V. The paper begins with a theo... Read More about SiC/GaN power semiconductor devices: a theoretical comparison and experimental evaluation under different switching conditions.

Using multi time-scale electro-thermal simulation approach to evaluate SiC-MOSFET power C=converter in virtual prototyping design tool (2017)
Conference Proceeding
Li, K., Evans, P., & Johnson, C. M. (in press). Using multi time-scale electro-thermal simulation approach to evaluate SiC-MOSFET power C=converter in virtual prototyping design tool.

Using virtual prototyping (VP) design tool to eval¬uate power converter electro-thermal performance can help designers to validate prototype in a quick way. However, different system time-scale requires efficient electro-thermal simulation techniques... Read More about Using multi time-scale electro-thermal simulation approach to evaluate SiC-MOSFET power C=converter in virtual prototyping design tool.

Highly-integrated power cell for high-power wide band-gap power converters (2017)
Conference Proceeding
Espina, J., Ahmadi, B., Empringham, L., De Lillo, L., & Johnson, C. M. (2017). Highly-integrated power cell for high-power wide band-gap power converters.

The fast switching speeds and low specific conduction losses of wide band-gap semiconductors allow the realisation of high-frequency, high power-density switching converters with dramatically reduced passive component requirements compared to Silicon... Read More about Highly-integrated power cell for high-power wide band-gap power converters.

Design and construction of a co-planar power bus interconnect for low inductance switching (2017)
Conference Proceeding
Lin, X., Li, J., & Johnson, M. (2017). Design and construction of a co-planar power bus interconnect for low inductance switching. In 2017 IEEE International Workshop On Integrated Power Packaging (IWIPP) (1-4). https://doi.org/10.1109/IWIPP.2017.7936755

A co-planar tab-slot type of interconnect demonstrator for connecting power switching devices and DC bus capacitors has been designed and constructed, aimed at low inductance switching. The demonstrator is composed of a double-sided tab connector and... Read More about Design and construction of a co-planar power bus interconnect for low inductance switching.

A Physical RC Network Model for Electrothermal Analysis of a Multichip SiC Power Module (2017)
Journal Article
Li, J., Castellazzi, A., Eleffendi, M. A., Gurpinar, E., Johnson, C. M., & Mills, L. (2018). A Physical RC Network Model for Electrothermal Analysis of a Multichip SiC Power Module. IEEE Transactions on Power Electronics, 33(3), 2494-2508. https://doi.org/10.1109/TPEL.2017.2697959

© 2017 IEEE. This paper is concerned with the thermal models which can physically reflect the heat-flow paths in a lightweight three-phase half-bridge two-level SiC power module with six MOSFETs and can be used for coupled electrothermal simulation.... Read More about A Physical RC Network Model for Electrothermal Analysis of a Multichip SiC Power Module.

Interconnect materials enabling IGBT modules to achieve stable short circuit failure behavior (2017)
Journal Article
Li, J., Yaqub, I., Corfield, M., & Johnson, C. M. (2017). Interconnect materials enabling IGBT modules to achieve stable short circuit failure behavior. IEEE Transactions on Components, Packaging, and Manufacturing Technology, 7(5), 734-744. https://doi.org/10.1109/TCPMT.2017.2683202

Insulated gate bipolar transistor (IGBT) modules, which can fail to stable short-circuit mode, have major applications in electricity network-related fields. Sn-3.5Ag solder joints and sintered Ag joints for the die attachment and Mo, Cu, Sn-3.5Ag, A... Read More about Interconnect materials enabling IGBT modules to achieve stable short circuit failure behavior.

Suppression of electromagnetic interference using screening and shielding techniques within switching cells (2017)
Conference Proceeding
Zhang, Z., & Johnson, C. M. (2017). Suppression of electromagnetic interference using screening and shielding techniques within switching cells.

in this paper we introduce the use of combination of screening and shielding to suppress electromagnetic interference (EMI) generated by a switching cell. We investigate the screening of common mode (CM) currents and the shielding of magnetic fields... Read More about Suppression of electromagnetic interference using screening and shielding techniques within switching cells.

In-Service Diagnostics for Wire-Bond Lift-off and Solder Fatigue of Power Semiconductor Packages (2017)
Journal Article
Eleffendi, M. A., & Johnson, C. M. (2017). In-Service Diagnostics for Wire-Bond Lift-off and Solder Fatigue of Power Semiconductor Packages. IEEE Transactions on Power Electronics, 32(9), 7187-7198. https://doi.org/10.1109/TPEL.2016.2628705

Wire-bond lift-off and Solder fatigue are degradation mechanisms that dominate the lifetime of power semiconductor packages. Although their lifetime is commonly estimated at the design stage, based on mission profiles and Physics-of-Failure models, t... Read More about In-Service Diagnostics for Wire-Bond Lift-off and Solder Fatigue of Power Semiconductor Packages.

SiC and GaN power transistors switching energy evaluation in hard and soft switching conditions (2016)
Conference Proceeding
Li, K., Evans, P., & Johnson, C. M. (2016). SiC and GaN power transistors switching energy evaluation in hard and soft switching conditions.

SiC and GaN power transistors switching energy are compared in this paper. In order to compare switching energy Esw of the same power rating device, a theoretical analysis is given to compare SiC device conduction loss and switching losses change whe... Read More about SiC and GaN power transistors switching energy evaluation in hard and soft switching conditions.

A novel full soft-switching resonant power converter for mid-feeder voltage regulation of low voltage distribution network (2016)
Conference Proceeding
Ji, C., Watson, A. J., Clare, J. C., & Johnson, C. M. (2016). A novel full soft-switching resonant power converter for mid-feeder voltage regulation of low voltage distribution network. In 2016 18th European Conference on Power Electronics and Applications (EPE'16 ECCE Europe) (1-6). https://doi.org/10.1109/EPE.2016.7695398

This paper presents a novel resonant based, high power density power electronics converter solution for mid-feeder voltage regulation of a low voltage (LV) distribution network. Owing to the use of high switching frequency operation and a full soft-s... Read More about A novel full soft-switching resonant power converter for mid-feeder voltage regulation of low voltage distribution network.

SiC/GaN power semiconductor devices theoretical comparison and experimental evaluation (2016)
Conference Proceeding
Li, K., Evans, P., & Johnson, C. M. (2016). SiC/GaN power semiconductor devices theoretical comparison and experimental evaluation.

SiC and GaN power transistors conduction loss and switching losses are compared in this paper. In order to compare performance of the same power rating device, a theoretical analysis is given to compare SiC device conduction loss and switching losses... Read More about SiC/GaN power semiconductor devices theoretical comparison and experimental evaluation.

Developing power semiconductor device model for virtual prototyping of power electronics systems (2016)
Conference Proceeding
Li, K., Evans, P., & Johnson, C. M. (2016). Developing power semiconductor device model for virtual prototyping of power electronics systems.

Virtual prototyping (VP) is very important for power electronics systems design. A virtual prototyping design tool based on different modelling technology and model order reduction is proposed in the paper. In order to combine circuit electromagnetic... Read More about Developing power semiconductor device model for virtual prototyping of power electronics systems.

GaN-HEMT dynamic ON-state resistance characterisation and modelling (2016)
Conference Proceeding
Li, K., Evans, P., & Johnson, C. M. (2016). GaN-HEMT dynamic ON-state resistance characterisation and modelling.

GaN-HEMTs suffer from trapping effects which might increase device ON-state resistance (RDS(on)) values. Thus, dynamic RDS(on) of a commercial GaN-HEMT is characterized at different bias voltages in the paper by a proposed measurement circuit. Based... Read More about GaN-HEMT dynamic ON-state resistance characterisation and modelling.

Damage Evolution in Al Wire Bonds Subjected to a Junction Temperature Fluctuation of 30K (2016)
Journal Article
Agyakwa, P., Yang, L., Arjmand, E., Evans, P., Corfield, M., & Johnson, C. M. (2016). Damage Evolution in Al Wire Bonds Subjected to a Junction Temperature Fluctuation of 30K. Journal of Electronic Materials, 45, 3659-3672. https://doi.org/10.1007/s11664-016-4519-0

© 2016, The Author(s). Ultrasonically bonded heavy Al wires subjected to a small junction temperature fluctuation under power cycling from 40°C to 70°C were investigated using a non-destructive three-dimensional (3-D) x-ray tomography evaluation appr... Read More about Damage Evolution in Al Wire Bonds Subjected to a Junction Temperature Fluctuation of 30K.

Predicting Lifetime of Thick Al Wire Bonds Using Signals Obtained From Ultrasonic Generator (2016)
Journal Article
Arjmand, E., Agyakwa, P., Corfield, M., Li, J., & Johnson, C. M. (2016). Predicting Lifetime of Thick Al Wire Bonds Using Signals Obtained From Ultrasonic Generator. IEEE Transactions on Components, Packaging, and Manufacturing Technology, 6(5), 814-821. https://doi.org/10.1109/TCPMT.2016.2543001

Routine monitoring of the wire bonding process requires real-time evaluation and control of wire bond quality. In this paper, we present a nondestructive technique for detecting bond quality by the application of a semisupervised classification algor... Read More about Predicting Lifetime of Thick Al Wire Bonds Using Signals Obtained From Ultrasonic Generator.

Integrated motor drives: state of the art and future trends (2016)
Journal Article
Abebe, R., Vakil, G., Lo Calzo, G., Cox, T., Lambert, S., Johnson, C. M., …Mecrow, B. (2016). Integrated motor drives: state of the art and future trends. IET Electric Power Applications, 10(8), 757-771. https://doi.org/10.1049/iet-epa.2015.0506

With increased need for high power density, high efficiency and high temperature capabilities in aerospace and automotive applications, integrated motor drives (IMD) offers a potential solution. However, close physical integration of the converter an... Read More about Integrated motor drives: state of the art and future trends.

Hybrid HVDC circuit breaker with self-powered gate drives (2016)
Journal Article
Effah, F. B., Watson, A. J., Ji, C., Amankwah, E. K., Johnson, C. M., Davidson, C., & Clare, J. C. (2016). Hybrid HVDC circuit breaker with self-powered gate drives. IET Power Electronics, 9(2), 228-236. https://doi.org/10.1049/iet-pel.2015.0531

The ever increasing electric power demand and the advent of renewable energy sources have revived the interest in high-voltage direct current (HVDC) multi-terminal networks. However, the absence of a suitable circuit breaker or fault tolerant VSC st... Read More about Hybrid HVDC circuit breaker with self-powered gate drives.

Low inductance 2.5kV packaging technology for SiC switches (2016)
Conference Proceeding
Mouawad, B., Li, J., Castellazzi, A., Johnson, C. M., Erlbacher, T., & Friedriches, P. (2016). Low inductance 2.5kV packaging technology for SiC switches.

The switching speed of power semiconductors has reached levels where conventional semiconductors packages limit the achievable performance due to relatively high parasitic inductance and capacitance. This paper presents a novel packaging structure wh... Read More about Low inductance 2.5kV packaging technology for SiC switches.

Real-time deterministic power flow control through dispatch of distributed energy resources (2015)
Journal Article
Fazeli, A., Sumner, M., Johnson, C. M., & Christopher, E. (2015). Real-time deterministic power flow control through dispatch of distributed energy resources. IET Generation, Transmission and Distribution, 9(16), https://doi.org/10.1049/iet-gtd.2015.0182

Integration of intermittent renewable resources and mass electrification of heat and transport into the existing electricity network, with limited network asset reinforcement requires incorporation of intelligence in form of active management of flex... Read More about Real-time deterministic power flow control through dispatch of distributed energy resources.

Dependence of overcurrent failure modes of IGBT modules on interconnect technologies (2015)
Journal Article
Yaqub, I., Li, J., & Johnson, C. M. (2015). Dependence of overcurrent failure modes of IGBT modules on interconnect technologies. Microelectronics Reliability, 55(12), 2596-2605. https://doi.org/10.1016/j.microrel.2015.09.020

Insulated gate bipolar transistor (IGBT) modules which can fail to short circuit mode have great of applications in electricity network related fields. Single IGBT samples have been constructed with the standard Al wire bonding, flexible printed circ... Read More about Dependence of overcurrent failure modes of IGBT modules on interconnect technologies.

Application of Kalman Filter to Estimate Junction Temperature in IGBT Power Modules (2015)
Journal Article
Eleffendi, M. A., & Johnson, C. M. (2016). Application of Kalman Filter to Estimate Junction Temperature in IGBT Power Modules. IEEE Transactions on Power Electronics, 31(2), 1576-1587. https://doi.org/10.1109/TPEL.2015.2418711

Knowledge of instantaneous junction temperature is essential for effective health management of power converters, enabling safe operation of the power semiconductors under all operating conditions. Methods based on fixed thermal models are typically... Read More about Application of Kalman Filter to Estimate Junction Temperature in IGBT Power Modules.

A novel stochastic modelling approach for electric vehicle charging power and energy requirements (2015)
Conference Proceeding
Fazeli, A., Johnson, C. M., Sumner, M., & Christopher, E. (2015). A novel stochastic modelling approach for electric vehicle charging power and energy requirements.

Electrification of heat and transport in addition to integration of intermittent renewable resources into the existing electricity network is expected to occur in near future. Such a transformation is expected to force the operation of the electricit... Read More about A novel stochastic modelling approach for electric vehicle charging power and energy requirements.

Investigating the impact of varying the number of distributed energy resources on controlling the power flow within a microgrid (2015)
Conference Proceeding
Fazeli, A., Sumner, M., Johnson, C. M., & Christopher, E. (2015). Investigating the impact of varying the number of distributed energy resources on controlling the power flow within a microgrid.

The electrification of heat and transport in addition to integration of intermittent renewable resources into the existing electricity network is expected to occur in near future. Such a transformation is expected to force the operation of the electr... Read More about Investigating the impact of varying the number of distributed energy resources on controlling the power flow within a microgrid.

Power flow control for power and voltage management in future smart energy communities (2014)
Conference Proceeding
Fazeli, A., Sumner, M., Christopher, E., & Johnson, C. M. (2014). Power flow control for power and voltage management in future smart energy communities.

The Community Power Flow Control (CPFC) Algorithm has been proposed as a technique for managing electrical power and energy within small communities. The CPFC manages the resources in the community (DSM, energy storage, RES) in order to control the c... Read More about Power flow control for power and voltage management in future smart energy communities.

Mission Profile-Based Reliability Design and Real-Time Life Consumption Estimation in Power Electronics (2014)
Journal Article
Mussallam, M., Yin, C., Bailey, C., & Johnson, C. M. (2015). Mission Profile-Based Reliability Design and Real-Time Life Consumption Estimation in Power Electronics. IEEE Transactions on Power Electronics, 30(5), 2601-2613. https://doi.org/10.1109/TPEL.2014.2358555

Power electronics are efficient for conversion and conditioning of the electrical energy through a wide range of applications. Proper life consumption estimation methods applied for power electronics that can operate in real time under in-service mis... Read More about Mission Profile-Based Reliability Design and Real-Time Life Consumption Estimation in Power Electronics.

Built-in reliability design of highly integrated solid-state power switches with metal bump interconnects (2014)
Journal Article
Li, J., Castellazzi, A., Dai, T., Corfield, M., Solomon, A. K., & Johnson, C. M. (2015). Built-in reliability design of highly integrated solid-state power switches with metal bump interconnects. IEEE Transactions on Power Electronics, 30(5), https://doi.org/10.1109/TPEL.2014.2357334

A stacked substrate–chip–bump–chip–substrate assembly has been demonstrated in the construction of power switch modules with high power density and good electrical performance. In this paper, special effort has been devoted to material selection and... Read More about Built-in reliability design of highly integrated solid-state power switches with metal bump interconnects.

Reliability of thick Al wire: a study of the effects of wire bonding parameters on thermal cycling degradation rate using non-destructive methods (2014)
Journal Article
Arjmand, E., Agyakwa, P. A., & Johnson, C. M. (2014). Reliability of thick Al wire: a study of the effects of wire bonding parameters on thermal cycling degradation rate using non-destructive methods. Microelectronics Reliability, 54(9-10), https://doi.org/10.1016/j.microrel.2014.07.119

The effect of bonding parameters on the reliability of thick Al wire bond is investigated. Samples were prepared with 25 different designs with 5 different bonding parameters such as time, ultrasonic power, begin- force, end-force and touch-down step... Read More about Reliability of thick Al wire: a study of the effects of wire bonding parameters on thermal cycling degradation rate using non-destructive methods.

Bonding strength of multiple SiC die attachment prepared by sintering of Ag nanoparticles (2014)
Journal Article
Li, J., Johnson, C. M., Buttay, C., Sabbah, W., & Azzopardi, S. (2015). Bonding strength of multiple SiC die attachment prepared by sintering of Ag nanoparticles. Journal of Materials Processing Technology, 215, 299-308. https://doi.org/10.1016/j.jmatprotec.2014.08.002

3 mm × 3 mm dummy SiC dies with 100\200\200 nm thick Ti\W\Au metallization have simultaneously been attached using sintering of Ag nanoparticle paste on AlN-based direct bonded copper substrates with 5\0.1 μm thick NiP\Au finish. The effect of prepar... Read More about Bonding strength of multiple SiC die attachment prepared by sintering of Ag nanoparticles.

Integrated Half-Bridge Switch Using 70- ?m-Thin Devices and Hollow Interconnects (2014)
Journal Article
Solomon, A. K., Li, J., Castellazzi, A., & Johnson, C. M. (2015). Integrated Half-Bridge Switch Using 70- ?m-Thin Devices and Hollow Interconnects. IEEE Transactions on Industry Applications, 51(1), 556-566. https://doi.org/10.1109/TIA.2014.2334734

An application-oriented integration concept for a half-bridge switch assembly has been developed based on the latest generation 70- ?m-thin insulated gate bipolar transistors and diodes, which are rated at 600 V/200 A. This paper addresses the design... Read More about Integrated Half-Bridge Switch Using 70- ?m-Thin Devices and Hollow Interconnects.

Interdiffusion coefficients of binary multiphase systems with consideration of variation in Molar volumes (2014)
Journal Article
Li, J., Agyakwa, P., & Johnson, C. M. (2014). Interdiffusion coefficients of binary multiphase systems with consideration of variation in Molar volumes

This communication introduces a modification to the Wagner method to reveal and correct considerable systematic errors existing in the previously established analytical methods used to calculate the interdiffusion coefficients of binary multiphase sy... Read More about Interdiffusion coefficients of binary multiphase systems with consideration of variation in Molar volumes.

A non-destructive study of crack development during thermal cycling of Al wire bonds using x-ray computed tomography (2014)
Conference Proceeding
Agyakwa, P., Yang, L., Corfield, M., & Johnson, C. M. (2014). A non-destructive study of crack development during thermal cycling of Al wire bonds using x-ray computed tomography.

This paper concerns the non-destructive visualisation of the evolution of damage within ultrasonically bonded alumini-um wires using three dimensional x-ray computed tomography. We demonstrate the potential to observe the progressive accumulation of... Read More about A non-destructive study of crack development during thermal cycling of Al wire bonds using x-ray computed tomography.

Suitable Thicknesses of Base Metal and Interlayer, and Evolution of Phases for Ag/Sn/Ag Transient liquid-phase Joints Used for Power Die Attachment (2014)
Journal Article
Li, J., Agyakwa, P., & Johnson, C. (2014). Suitable Thicknesses of Base Metal and Interlayer, and Evolution of Phases for Ag/Sn/Ag Transient liquid-phase Joints Used for Power Die Attachment. Journal of Electronic Materials, 43(4), 983-995. https://doi.org/10.1007/s11664-013-2971-7

Real Si insulated gate bipolar transistors with conventional Ni/Ag metallization and dummy Si chips with thickened Ni/Ag metallization have both been bonded, at 250°C for 0 min, 40 min, and 640 min, to Ag foil electroplated with 2.7 μm and 6.8 μm thi... Read More about Suitable Thicknesses of Base Metal and Interlayer, and Evolution of Phases for Ag/Sn/Ag Transient liquid-phase Joints Used for Power Die Attachment.

Design Optimization of Quasi-Active Gate Control for Series-Connected Power Devices (2013)
Journal Article
Teerakawanich, N., & Johnson, C. M. (2014). Design Optimization of Quasi-Active Gate Control for Series-Connected Power Devices. IEEE Transactions on Power Electronics, 29(6), 2705-2714. https://doi.org/10.1109/TPEL.2013.2274158

This paper presents a new gate drive circuit for driving a series string of insulated-gate bipolar transistors (IGBTs). The proposed quasi-active gate control (QAGC) circuit is simple to implement as it consists of only a few passive components in ad... Read More about Design Optimization of Quasi-Active Gate Control for Series-Connected Power Devices.

Hybrid half-bridge package for high voltage application
Conference Proceeding
Mouawad, B., Li, J., Castellazzi, A., & Johnson, C. M. (in press). Hybrid half-bridge package for high voltage application.

3D power module structures allow for better cooling and lower parasitic inductances compared with the classical planar technology. In this paper, we present a hybrid half-bridge in a 3D packaging configuration, dedicated for high voltage application.... Read More about Hybrid half-bridge package for high voltage application.

Low parasitic inductance multi-chip SiC devices packaging technology
Conference Proceeding
Li, J., Mouawad, B., Castellazzi, A., Friedrichs, P., & Johnson, C. M. (in press). Low parasitic inductance multi-chip SiC devices packaging technology.

This paper presents a novel packaging structure which employs stacked substrate and flexible printed circuit board (PCB) to obtain very low parasitic inductance and hence feature high switching speed SiC power devices. A half-bridge module aimed at b... Read More about Low parasitic inductance multi-chip SiC devices packaging technology.

Selection of materials for IGBT modules to achieve stable short circuit failure behaviour
Conference Proceeding
Li, J., Yaqub, I., & Johnson, C. M. (in press). Selection of materials for IGBT modules to achieve stable short circuit failure behaviour.

IGBT modules which can fail to stable short circuit mode have great allocations in electricity network related fields. Sn3.5Ag solder joint and sintered Ag joint for the die attachment and Mo, Cu, Sn3.5Ag, Al and Ag foils for the top side insert mate... Read More about Selection of materials for IGBT modules to achieve stable short circuit failure behaviour.

Reliable integration of a high performance multi-chip half-bridge SiC power module
Conference Proceeding
Mouawad, B., Li, J., Castellazzi, A., & Johnson, C. M. (in press). Reliable integration of a high performance multi-chip half-bridge SiC power module.

Silicon carbide (SiC) devices have been adopted to push the boundaries further in terms of power density, conversion efficiency, switching speed or thermal capability. To have the benefit of such semiconductors, new packaging should be developed to m... Read More about Reliable integration of a high performance multi-chip half-bridge SiC power module.

Packaging/assembling technologies for a high performance SiC-based planar power module
Conference Proceeding
Li, J., Agyakwa, P., Evans, P., Johnson, C. M., Zhao, Y., Wu, Y., & Evans, K. (in press). Packaging/assembling technologies for a high performance SiC-based planar power module.

This work is to investigate the relevant packaging / assembling technologies for developing a SiC-based planar power module which is aimed to meet the requirements such as operating temperature of -60 °C to 200 °C, SiC devices connected to 540 V DC b... Read More about Packaging/assembling technologies for a high performance SiC-based planar power module.