La modernità italiana vista dall’Europa. Un’immagine alla rovescia

Italy, indeed, falls behind in Europe in every statistics concerning with civil liberties, university education, and competitiveness and all this thanks to politicians that were not able to keep the country tight with Europe, with its idea of efficiency and modernism that, with its contradictions, Europe represents

Silicon-germanium heterojunction bipolar transistors for mm-wave systems technology, modeling and circuit applications

The semiconductor industry is a fundamental building block of the new economy, there is no area of modern life untouched by the progress of nanoelectronics. The electronic chip is becoming an ever-increasing portion of system solutions, starting initially from less than 5% in the 1970 microcomputer era, to more than 60% of the final cost of a mobile telephone, 50% of the price of a personal computer (representing nearly 100% of the functionalities) and 30% of the price of a monitor in the early 2000’s. Interest in utilizing the (sub-)mm-wave frequency spectrum for commercial and research applications has also been steadily increasing. Such applications, which constitute a diverse but sizeable future market, span a large variety of areas such as health, material science, mass transit, industrial automation, communications, and space exploration. Silicon-Germanium Heterojunction Bipolar Transistors for mm-Wave Systems Technology, Modeling and Circuit Applications provides an overview of results of the DOTSEVEN EU research project, and as such focusses on key material developments for mm-Wave Device Technology. It starts with the motivation at the beginning of the project and a summary of its major achievements. The subsequent chapters provide a detailed description of the obtained research results in the various areas of process development, device simulation, compact device modeling, experimental characterization, reliability, (sub-)mm-wave circuit design and systems.Note.- EUR 6,000 BPC fee funded by the EC FP7 Post-Grant Open Access Pilo

Advanced thermal simulation of SiGe:C HBTs including back-end-of-line

Advanced 3-D thermal simulations of state-of-the-art SiGe:C HBTs are performed, which ensure improved accuracy with respect to conventional approaches. The whole back-end-of-line architecture is modeled so as to account for the cooling effect due to the upward heat flow. Moreover, a nonuniform power density is considered to describe the heat source, and thermal conductivity degradation effects due to germanium, doping profile, and phonon scattering in narrow layers are implemented. The numerical thermal resistances are compared with those experimentally evaluated by means of a robust technique relying on the temperature dependence of the base-emitter voltage

3-D thermal models calibration by parametric dynamic compact thermal models

Detailed 3-D thermal models of electronic systems require the calibration of unknown parameters to accurately describe the experimental data, which is usually obtained by a least square optimization of the measured transient thermal response to a given set of power inputs. This paper presents an extremely efficient technique to perform the identification of boundary conditions, material thermal properties, and geometrical sizes, which is based on the adoption of the trust region algorithm in combination with parametric dynamic compact thermal models. The calibration of parameters of a Package-on-Package system is performed by a simulated experiment procedure to validate the applicability and accuracy of the proposed approach. It is shown that using parametric compact models allows for a significant reduction in computational effort in comparison to conventional brute-force optimization. The calibration robustness with respect to input degradation is examined by observing the variation in the extracted parameters at different levels of noise

Novel partition-based approach to dynamic compact thermal modeling

A novel partition-based approach for the extraction of Dynamic Compact Thermal Models is presented. With respect to previous approaches, this methodology allows reducing the complexity of the constructed models, from quadratically to linearly dependent on the number of independent heat sources. The proposed methodology is validated through the application to two state-of-the-art electronic systems

Calibration of detailed thermal models by parametric dynamic compact thermal models

In this paper it is shown how parametric dynamic compact thermal models can be exploited for the calibration of detailed thermal models of electronic components and packages. A constrained least square fit of the thermal response of a parametric dynamic compact thermal model, having as parameters the material thermal properties and geometrical details to be calibrated, onto the measured temperature response is performed. Numerical results show that the use of parametric dynamic compact thermal models instead of detailed compact thermal models, in conjunction with an optimization algorithm solving the constrained least square problem, can reduce the computational time for calibration by more than two orders of magnitude

Reviews of A.W. Heringa, MJ

No abstract available

Reviews of A.W. Heringa, MJ 18–3 (2011), p. 221–224

No abstract available

Partition-based approach to parametric dynamic compact thermal modeling

This paper presents three procedures for the extraction of parametric Dynamic Compact Thermal Models (DCTMs) with controlled and user-chosen accuracy, namely, (i) a DCTM with dense matrices obtained by a direct conventional method, (ii) a partition-based approach leading to a sparse DCTM suited for heat conduction problems suffering from a massive number of independent heat sources and/or parameters, for which extracting conventional dense DCTMs may be too resource-demanding or even unviable, and (iii) a novel algorithm that quickly translates a sparse DCTM into a dense one, which allows reducing the simulation time. The proposed methodologies are validated through the application to two state-of-the-art electronics systems