BEM calculation of the complex thermal impedance of microelectronic devices

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IGBT package design for high power aircraft electronic systems

This paper will discuss the design of semiconductor packages having integrated air cooled heatsinks for use in high power electronic systems. It will demonstrate how simple models of the heat transfer from the heatsink fins, which are based on empirical correlations, may be utilised in combination with either simple analytical models or two dimensional finite difference (FD) models of the heat conduction from the semiconductor die through the multilayer package structure to the base of the fins. These models allow the rapid evaluation of performance under both steady state and transient overload conditions, and can be used to rapidly explore a wide range of design options before selecting candidate layouts for more detailed evaluation using, for example, 3D FD analysis. Wind tunnel experiments, which will also be reported, have been carried out to verify the modelling results for different semiconductor device layouts. These trials demonstrate excellent agreement between the models and experimental results

Modeling Solder Ball Array Interconnects for Power Module Optimization

PowerSynth is a software platform that can co-optimize power modules utilizing a 2D topology and wire bond interconnects. The novel 3D architectures being proposed at the University of Arkansas utilize solder ball interconnects instead of wire bonds. Therefore, they currently cannot be optimized using PowerSynth. This paper examines methods to accurately model the parasitic inductance of solder balls and ball grid arrays so they may be implemented into software for optimization. Proposed mathematical models are validated against ANSYS Electromagnetics Suite simulations. A comparison of the simulated data shows that mathematical models are well suited for implementation into optimization software platforms. Experimental measurements proved to be inconclusive and necessitate future work

Coupled Simulation of Transient Heat Flow and Electric Currents in Thin Wires: Application to Bond Wires in Microelectronic Chip Packaging

This work addresses the simulation of heat flow and electric currents in thin wires. An important application is the use of bond wires in microelectronic chip packaging. The heat distribution is modeled by an electrothermal coupled problem, which poses numerical challenges due to the presence of different geometric scales. The necessity of very fine grids is relaxed by solving and embedding a 1D sub-problem along the wire into the surrounding 3D geometry. The arising singularities are described using de Rham currents. It is shown that the problem is related to fluid flow in porous 3D media with 1D fractures [C. D'Angelo, SIAM Journal on Numerical Analysis 50.1, pp. 194-215, 2012]. A careful formulation of the 1D-3D coupling condition is essential to obtain a stable scheme that yields a physical solution. Elliptic model problems are used to investigate the numerical errors and the corresponding convergence rates. Additionally, the transient electrothermal simulation of a simplified microelectronic chip package as used in industrial applications is presented.Comment: all numerical results can be reproduced by the Matlab code openly available at https://github.com/tc88/ETwireSi

Advancing automation and robotics technology for the space station and for the US economy: Submitted to the United States Congress October 1, 1987

In April 1985, as required by Public Law 98-371, the NASA Advanced Technology Advisory Committee (ATAC) reported to Congress the results of its studies on advanced automation and robotics technology for use on the space station. This material was documented in the initial report (NASA Technical Memorandum 87566). A further requirement of the Law was that ATAC follow NASA's progress in this area and report to Congress semiannually. This report is the fifth in a series of progress updates and covers the period between 16 May 1987 and 30 September 1987. NASA has accepted the basic recommendations of ATAC for its space station efforts. ATAC and NASA agree that the mandate of Congress is that an advanced automation and robotics technology be built to support an evolutionary space station program and serve as a highly visible stimulator affecting the long-term U.S. economy

Systems design analysis applied to launch vehicle configuration

As emphasis shifts from optimum-performance aerospace systems to least lift-cycle costs, systems designs must seek, adapt, and innovate cost improvement techniques in design through operations. The systems design process of concept, definition, and design was assessed for the types and flow of total quality management techniques that may be applicable in a launch vehicle systems design analysis. Techniques discussed are task ordering, quality leverage, concurrent engineering, Pareto's principle, robustness, quality function deployment, criteria, and others. These cost oriented techniques are as applicable to aerospace systems design analysis as to any large commercial system

Thermal design of high power semiconductor packages for aircraft electronic systems

The More Electric Aircraft is likely to require more extensive use of power electronics, for which thermal management will be a key issue. This paper presents an approach to designing integrated air cooled heatsinks which is being developed by Loughborough University as part of the CARAD funded Variable Frequency to Constant Frequency (VFCF) Converter project in collaboration with project partners TRW Aeronautical Systems, Mitel Semiconductor, AEA Technology and BAe Airbus. The paper shows how simple models of the heat transfer from heatsink fins, which are based on well established empirical correlations, may be utilised in combination with either simple analytical models or two dimensional finite element models of the heat conduction from the semiconductor die through the multilayer package structure to the base of the fins. These models allow the generation of design curves which may be used to rapidly explore a wide range of design options before selecting potential designs for more detailed evaluation using 3D FE analysis. In systems such as a VFCF convertor the semiconductor devices are switched at high frequency to ensure good input and output current waveforms. The power dissipated in the semiconductors, and therefore the heatsink weight, will however increase with the switching frequency, whereas the associated filtering components will be smaller and lighter at higher frequencies. The optimisation of the overall system weight therefore involves a tradeoff between the heatsinking and filtering requirements rather than just determining the optimum heatsink design for a specific power dissipatio