Adam Morgan

Decomposition and electro-physical model creation of the CREE 1200V, 50A 3-Ph SiC module

The CREE 1200V/50A, 25mΩ 6-Pack SiC MOSFET module (CCS050M12CM2) is decomposed into a full 3D CAD model, and materials identified, for use in electrical circuit and multi-physics simulations. A reverse engineering technique is first developed, outlined, and then demonstrated on the CREE module. The ANSYS Q3D Extractor is applied to the 3D CAD model where electrical, lumped parameter, parasitic circuit elements are determined. The model is also analyzed with a multi-physics simulator to provide in-situ thermal maps of the baseplate surface for application scenarios, e.g. with a thermal interface material and pin fin heat sink to capture the thermal spreading from junction to case. The complete model is made open source and freely distributed for use by the reader.

Design methodology for a planarized high power density EV/HEV traction drive using SiC power modules

This paper provides a methodology for overall system level design of a high-power density inverter to be used for EV/HEV traction drive applications. The system design is guided to accommodate off-the-shelf SiC power modules in a planar architecture that ensures proper electrical, thermal, and mechanical performances. Bi-directional interleaved DC-DC boost structure and a three-phase voltage source inverter (VSI) have been utilized with the primary focus on the size, weight and loss reduction of passive components. A stacked layer approach has been used for a unique PCB-based busbar, ultra-low profile gate driver, and controller board. This holistic design approach results in a highly compact traction drive inverter with power density of 12.1 kW/L that has lower volume and weight compared to the commercially available state-of-the-art power converter systems.

Design Considerations of Packaging a High Voltage Current Switch

In this paper an attempt has been made to demonstrate various package design considerations to accommodate series connection of high voltage Si-IGBT (6500V/25A die) and SiC-Diode (6500V/25A die). The effects of connecting the cathode of the series diode to the collector of the IGBT versus connecting the emitter of the IGBT to the anode of the series diode has been analyzed in regards to gate terminal operation and the parasitic line inductance of the structure. ANSYS Q3D/MAXWELL software have been used to analyze and extract parasitic inductance and capacitances in the package along with electromagnetic fields, electric potentials, and current density distributions throughout the package for variable parameters. SIMPLIS-SIMETRIX is used to simulate typical switch behavior for different parasitic parameters under hard switched conditions. Various simulation results have then been used to redesign and justify the optimized package structure for the final current switch design. The thermal behavior of such a package is also conducted in COMSOL in order to ensure that the thermal ratings of the power devices is not exceeded, and to understand where potentially harmful hotspots could arise and estimate the maximum attainable frequency of operation. The main motivation of this work is to enumerate detailed design considerations for packing a high voltage current switch package.Copyright

Design, Package, and Hardware Verification of a High-Voltage Current Switch

In this paper, an attempt has been made to demonstrate various package design considerations to accommodate series connection of high voltage Si-IGBT (6500V/25A die) and SiC-Diode (6500V/25A die). The effects of connecting the cathode of the series diode to the collector of the IGBT versus connecting the emitter of the IGBT to the anode of the series diode have been analyzed in regards to parasitic line inductance of the structure. Various simulation results have then been used to redesign and justify the optimized package structure for the final current switch design. The package is fabricated using the optimized parameters. A double pulse test-circuit has been assembled. Initial hardware results have been shown to verify functioning. The main motivation of this work is to enumerate detailed design considerations for packing a high voltage current switch package.

Design, package, and hardware verification of a high voltage current switch

This paper demonstrates various electrical and package design considerations in series connecting a high-voltage (HV) silicon (Si)-IGBT (6500-V/25-A die) and a silicon carbide-junction barrier Schottky diode (6500-V/25-A die) to form an HV current switch. The effects of connecting the cathode of the series diode to an IGBT collector, versus connecting the IGBT emitter to the anode of the series diode, are analyzed in regards to minimizing the parasitic inductance. An optimized package structure is discussed and an HV current switch module is custom fabricated in the laboratory. An HV double pulse test circuit is used to verify the switching performance of the current switch module. Low-voltage and HV converter prototypes are developed and tested to ensure thermal stability of the same. The main motivation of this paper is to enumerate detailed design considerations for packaging an HV current switch.

A High Performance Power Module with >10kV capability to Characterize and Test In Situ SiC Devices at >200°C Ambient

Abstract This paper presents design, fabrication and characterization details of a 10kV power module package for >200°C ambient temperature applications. Electrical simulations were performed to confirm the module design, and that the electric field distribution throughout the module did not exceed dielectric capabilities of components and materials. A suitable copper etching process was demonstrated for DBC layout, and a high melting point Sn/Pb/Ag solder reflow process was developed for device and component attachment. To monitor the operational temperature of the module, a thermistor was integrated onto the substrate. A new silicone gel, having a working temperature up to 210°C, was evaluated and selected for encapsulation and, of great importance, for passivation of high voltage (10kV) SiC dies. An additive manufacturing ‘Design Process’ was developed and applied to printing the housings, molds, and test fixtures. Also, cleaning processes were evaluated for every step in the fabrication process. To ve...