Stephan Guttowski

High-Frequency Modeling of TSVs for 3-D Chip Integration and Silicon Interposers Considering Skin-Effect, Dielectric Quasi-TEM and Slow-Wave Modes

Through-silicon vias (TSVs) in low, medium and high resistivity silicon for 3-D chip integration and interposers are modeled and thoroughly characterized from 100 MHz to 130 GHz, considering the slow-wave, dielectric quasi-TEM and skin-effect modes. The frequency ranges of these modes and their transitions are predicted using resistivity-frequency domain charts. The impact of the modes on signal integrity is quantified, and three coaxial TSV configurations are proposed to minimize this impact. Finally, conventional expressions for calculating the per-unit-length circuit parameters of transmission lines are extended and used to analytically capture the frequency dependent behavior of TSVs, considering the impact of the mixed dielectric (silicon dioxide-silicon-silicon dioxide) around the TSVs. Excellent correlation is obtained between the analytical calculations using the extended expressions and electromagnetic field simulations up to 130 GHz. These extended expressions can be implemented directly in electronic design automation tools to facilitate performance evaluation of TSVs, prior to system design.

Efficient HF modeling and model parameterization of induction machines for time and frequency domain simulations

In this paper, a simple but highly accurate high frequency model of induction machines for time and frequency domain simulation is presented. The proposed model enables exact simulation of both, differential and common mode behavior in the EMI-frequency range up to 30MHz. All parameters are easily obtained by differential and common mode impedance measurements and proposed calculation methodology. The model is verified for several induction machines in the power range of 370W up to 45kW. Comparison of simulation and measurement results confirm the good compromise between simulation time and accuracy even in complex simulation problems

Analytical, Numerical-, and Measurement–Based Methods for Extracting the Electrical Parameters of Through Silicon Vias (TSVs)

In this paper, analytical, numerical-, and measurement-based methods for extracting the resistance, inductance, capacitance, and conductance of through silicon vias (TSVs) are classified, quantified, and compared from 100 MHz to 100 GHz. An in-depth analysis of the assumptions behind these methods is made, from which their limits of accuracy/validity are defined. Based on this, the most reliable methods within the studied frequency range are proposed. The TSVs are designed, fabricated, and measured. Very good correlation is obtained between electrical parameters of the TSVs extracted from the measurements and electromagnetic field simulations.

EMC issues in cars with electric drives

From the EMC point of view, the integration of electric drive systems into todays cars represents a substantial challenge. The electric drive system is a new component consisting of a high-voltage power source, a frequency converter, an electric motor and shielded or unshielded high-power cables. Treating this new electric drive system or its components as a conventional automotive component in terms of EMI test procedures and emission limits would lead to substantial incompatibility problems. In this paper, the EMC issues related to the integration of an electric drive system into a conventional passenger car are investigated. The components of the drive system have been analyzed being either noise sources or part of the coupling path within the new electrical system of the car. The obtained results can also be used to determine the acceptable noise levels on a high voltage bus of an electric drive system.

Simulating Electromagnetic Interactions in High Power Density Inverters

In high power density inverters with integrated functions like filters and control electronics electromagnetic interaction between components becomes an important issue. Especially filters for electromagnetic interference are very sensitive to electromagnetic fields and therefore critical to design. Nevertheless only few guidelines for optimizing placement of filter components were published up to now. This paper introduces a simulation method for predicting stray fields of components and conducting structures, which is verified experimentally for different passive components and setups. The examples demonstrate a possibility of handling interaction problems

Modeling, Quantification, and Reduction of the Impact of Uncontrolled Return Currents of Vias Transiting Multilayered Packages and Boards

The returning displacement currents of vias transiting multilayered stack-ups in electronic packages and boards excite parasitic transverse electromagnetic modes in power-ground plane pairs, causing them to behave as parallel-plate waveguides. These waves may cause significant coupling in the power-ground cavity, leading to electromagnetic reliability (EMR) issues such as simultaneous switching noise coupling, high insertion loss degradation of signal vias, and stray radiation from the periphery/edges of the package/board. In this contribution, we model and quantify EMR problems caused by uncontrolled return currents of signal vias in conventional multilayer stack-ups. Traditional methods used to minimize these problems, and their limitations are discussed. We propose a low-cost layer stack-up, which overcomes most of the limitations of conventional stack-ups by providing well-defined return-current paths for microstrip-to-microstrip via transitions. Test samples of the proposed configuration are designed, fabricated, and measured. Very good correlation is obtained between measurement and simulation. Finally, a circuit model for the microstrip-to-microstrip via transition, considering the return-current paths, is developed and the circuit parameters are analytically calculated. Conventional closed-form expressions used for the extraction of these parameters, particularly the via capacitance, are extended and modified.

A Methodology for Combined Modeling of Skin, Proximity, Edge, and Surface Roughness Effects

A methodology is introduced for modeling resistive losses in planar transmission lines that support the transverse electromagnetic mode. The methodology aims to accurately and systematically account for these losses by modeling the skin, proximity, edge, and surface roughness effects in a combined way. The results show a correlation with three measurements within 5%, and offer insight into the different sources of resistive losses at high frequencies. Considering a printed coplanar line as an example, approximately 8% of the resistive loss come from surface roughness, and 30% from the edge effects at 60 GHz. However, for a line with a higher conductivity metallization, this increases to 38% and 30%, respectively, from surface roughness and edge effects at only 20 GHz.

Rf-properties of automotive traction batteries

The application of electric motors and inverters for automotive traction leads to a significant increase in electromagnetic compatibility (EMC) problems. Especially the influence of traction batteries as part of the path for electromagnetic interference is not sufficiently investigated up to now. In this paper, models for battery behavior are derived from the structure of cylindrical and prismatic batteries. Therefore, material parameters are defined which describe the characteristics of the material used in the battery and allow the prediction of current distribution in the battery. The models are parameterized and verified by impedance measurements on Lithium ion (Li-ion) and nickel metal hydride (NiMH) batteries. The results allow the calculation of high frequency losses, the simulation of batteries as interference path and the prediction of external fields

Prediction of EMI behaviour in terms of passive component placement

The performance of EMI filters is severely influenced by the placement of passive components. This paper introduces a method to predict these effects and demonstrates its potential on a DC/DC-Converter for automotive applications. Design rules are derived for favourable placement of several types of passive components.

Miniaturization platform for wireless sensor nodes based on 3D-packaging technologies

Miniaturized wireless sensors are mostly easier to integrate into everyday objects and show very high mechanical robustness. The development of these embedded micro systems has to consider the interdependence of design decisions regarding network communication, wireless sensor hardware and fabrication technology. An event driven simulator in combination with a 3D placement tool was used to predict the total system volume. The potential miniaturization degree is derived according to different 3D packaging technologies. The results are verified by prototype implementations