MuSiCA will design and supply a power electronic module and gate driver using silicon carbide devices for a relatively high frequency 100kW aircraft motor drive application. The power converter topology has been chosen and is provided as an input to the project. The main objective is to package silicon carbide devices in a manufacture-able and reliable power module package to enable silicon carbide technology to meet its full potential in terms of competitiveness against current solutions. The power module package will be integrated with the gate driver developed in the project. The hardware will be produced during the project and tested on an existing Clean Sky 2 funded motor drive test bed. The output of the project will be a demonstration of the manufactured hardware and evidence of its manufacturability, reliability and low weight and volume, and potential to reduce CO2, NOx and Noise emissions. The target application is European Aerospace but the solutions developed will be applicable to other applications such as automotive, rail and renewable energy, where high reliability and manufacturability is desirable. The key objectives of MuSiCA are to: Increase manufacturability, Increase long term in-service reliability, Increase modularity and scalability, Integration with Clean Sky test bed, Maximise the performance of silicon carbide power semiconductor devices, Enable the demonstration of the complete power converter. The power electronics module developed in MuSiCA will support the Clean Sky ambitions. It is expected that MuSiCA will directly address the ITD Systems and in particular will feed into the WP5 and WP 100.1: “Power Electronics and Electrical Drives” The CfP supports the activities within the Systems Integrated Technology Demonstrators by delivering an innovative multi-level power electronics module which can be used as a functional building block for the construction of converters for a variety of uses in on-board energy conversion systems.

Many industrial applications make use of high voltage power electronic devices. Examples include traction, marine power and power system based power electronics. Further developments are currently taking place within the aerospace sector that will mean the market for such devices will continue to grow. Most of the applications that power electronic devices are used in demand reliable operation. In turn this means that care must be taken in the design of the insulation system. Modules that operate at voltages over 5kV are currently available and there will always be a drive to improve the power density of the module by raising voltages or by miniaturisation. To do this, weak points in the dielectric system must be progressively improved. A power electronic module is typically composed of a metallized substrate soldered onto a baseplate. Different techniques are used to achieve this such as directly bonded copper or active metal brazing. The high voltage silicon IGBTs / diodes are typically soldered this substrate that is itself made from aluminum nitride (AlN), a ceramic with a good insulation strength. Wire bonds are then used to make connections between the individual IGBT / diode terminals and external connections for gate drives / busbars. The whole assembly is immersed in a soft dielectric, typically silicone gel, in order to provide the dielectric strength along the surfaces of the substrate, between the busbars and any other parts of the module subject to high electric fields. An epoxy layer may then be placed over the top of the entire dielectric system. The critical area in which the insulation system of a power module is extremely weak is at the edge of the metallisation of the substrate. The performance of the silicon gel is particularly critical in this location not just in terms of preventing discharge within the gel itself but also in terms of preventing discharge at the gel-substrate interface in close proximity to the metallisation.The invention being developed by the University of Manchester relates to the modification of the dielectric system of a module thus reducing the probability of electric discharge at this interface. The use of the technology being developedwould help to reduce the high levels of failure rates that can currently occur on low volume production runs of high value power electronic modules. It would also significantly improve the reliability of power electronic modules as insulation defects that did not show up in initial testing but which exist and have the ability to cause cumulative damage would be reduced in severity by the technology.The funding of this project through the follow on fund mechanism will allow the technical case for the technology to be enhances through a more thorough understanding of the ability of technology to enhance the dielectric system and through the understanding of the relationship between the manufacturing process and the electrical performance. In parallel, the commercial activities that are discussed will allow the commercial case for the technology to be strengthened through the completion of a cost benefit analysis, the appraisal of the technology to be used in the next generation of power electronic modules and the identification of prospective partners.The close association with the University of Manchester Intellectual Property team will also allow the mechanism for long term promotion and development of this technology to be identified as well as understanding the ways in which the technology can be used in other technical areas.

Power electronic modules (PEMs) and higher-level systems play an increasingly important role in adjustable-speed drives, unified power quality correction, utility interfaces with renewable energy resources, energy storage systems, electric or hybrid electric vehicles and more electric ship/aircraft. The power electronic technologies provide compact and high-efficient solutions to power conversion but deployment of power electronic modules in such applications comes with challenges for their reliable and safe operation. This project aims to address four key challenges which the power electronics manufactures, and PEM end-users continue to face: Challenge 1: No in-line and non-destructive inspection methods for PEM package quality and internal integrity assessment (wire bonds, die attachment and encapsulant) embedded within the production line. Challenge 2: No comprehensive PEM data on design-quality-reliability characteristics, no processes for chartreisation and test data integration and management, and for data modelling and analysis. Challenge 3: No advanced capabilities for accurate assessment of PEM deployment risks and for lifetime management. Challenge 4: No or limited data is fed back from end-users to PEM designers/manufacturers, no application-informed design and manufacturing quality. The project seeks to develop a digitalised Data Analytics and Analysis Platform (DAAP) for PEMs. The following novel and beyond current state-of-art developments in the project address the above stated challenges: 1) Non-Destructive Testing (NDT) with real-time data acquisition capability. A novel technique for NDT using LF-OCT imaging will be enhanced and optimised to provide quality data for individual PEMs. The proposed NDT method can quantitatively measure the mechanical deformation of gel-encapsulated bonding wires down to nanometer level. It can capture an entire cross-sectional image without any mechanical scanning, providing novel capability of running in-line with the packaging process. 2) Quality Predictions using AI and Machine Learning (ML): Research on integration and use of multiple data formats and sources, including standard datasets of electrical parameter test measurements, image data from in-line LF-OCT, and off-line X-ray and other imaging techniques, will be undertaken. The integrated data will underpin the accurate and automated quality evaluation of each individual PEM by enabling the development of ML and Deep Learning models. The modelling capability will enable packaging quality evaluations based on comprehensive sets of design and packaging process attributes. 3) Reliability Predictions. Current state-of-art in design-reliability and in-service degradation modelling for PEMs will be advanced through the proposed inclusion of manufacturing quality characteristics and design attributes in the reliability predictions. This will result in enhanced knowledge and more accurate, quality-informed reliability modelling and insights into the relations between design, quality and reliability by analytics of manufacturing and end-user data. 4) Data-Modelling-Optimisation Capabilities' Integration. The proposed integration (DAAP) of data, information exchange, and different modelling capabilities with multi-objective optimisation methods will be a novel development. The proposed optimisation routines will provide new capabilities for power semiconductor packaging design (e.g. module architecture, materials, interconnect solutions, application-specific reliability performance, etc.) and optimal process control on the manufacturing line.