The Experts below are selected from a list of 13488 Experts worldwide ranked by ideXlab platform
Sherief Reda - One of the best experts on this subject based on the ideXlab platform.
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spectral techniques for high resolution Thermal Characterization with limited sensor data
Design Automation Conference, 2009Co-Authors: Ryan Cochran, Sherief RedaAbstract:Elevated chip temperatures are true limiters to the scalability of computing systems. Excessive runtime Thermal variations compromise the performance and reliability of integrated circuits. To address these Thermal issues, state-of-the-art chips have integrated Thermal sensors that monitor temperatures at a few selected die locations. These temperature measurements are then used by Thermal management techniques to appropriately manage chip performance. Thermal sensors and their support circuitry incur design overheads, die area, and manufacturing costs. In this paper, we propose a new direction for full Thermal Characterization of integrated circuits based on spectral Fourier analysis techniques. Application of these techniques to temperature sensing is based on the observation that die temperature is simply a space-varying signal, and that space-varying signals are treated identically to time-varying signals in signal analysis. We utilize Nyquist-Shannon sampling theory to devise methods that can almost fully reconstruct the Thermal status of an integrated circuit during runtime using a minimal number of Thermal sensors. We propose methods that can handle uniform and non-uniform Thermal sensor placements. We develop an extensive experimental setup and demonstrate the effectiveness of our methods by Thermally characterizing a 16-core processor. Our method produces full Thermal Characterization with an average absolute error of 0.6% using a limited number of sensors.
Ali Shakouri - One of the best experts on this subject based on the ideXlab platform.
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High Resolution Non-Contact Thermal Characterization Semiconductor Devices
2020Co-Authors: James Christofferson, Ali Shakouri, Daryoosh Vashaee, Philip Melese, Jack BaskinAbstract:Abstract : Non-contact optical methods can be used for sub micron surface Thermal Characterization of active semiconductor devices. Point measurements were first made, and then real time Thermal images were acquired with a specialized PINarray detector. This method of Thermal imaging can have spatial resolution better than the diffraction limit of an infrared camera and can work in a wide range of ambient temperatures. The experimentally obtained Thermal resolution is on the order of 50mK.
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High resolution Thermal Characterization of a GaAs MMIC
2015 IEEE Radio Frequency Integrated Circuits Symposium (RFIC), 2015Co-Authors: Dustin Kendig, Kazuaki Yazawa, Ali ShakouriAbstract:We present the high resolution Thermal Characterization of a GaAs MMIC. The Thermal imaging technique provides sub-microsecond temporal and sub-micron spatial resolutions. The results show that the gate area heats up in less than 3 us, much faster than the other area of the transistor. Also, the Thermal cross talk between transistor arrays takes place in 100s us. This imaging method revealed unique Thermal characteristics, not previously observed with traditional Thermal measurement techniques.
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Thermal Characterization of high power transistor arrays
2009 25th Annual IEEE Semiconductor Thermal Measurement and Management Symposium, 2009Co-Authors: Kerry Maize, Xi Wang, Dustin Kendig, Ali Shakouri, William French, Barry O'connell, Philip Lindorfer, Peter J. HopperAbstract:Thermal performance is an important factor in the design of power devices. Previous studies have shown that nonuniform temperature distributions occur in both small transistors [1,2,3] and in large area power transistor devices [4,5,6]. We present extensive Thermal Characterization of large scale transistor arrays that are typical in power applications. Thermal images using the thermoreflectance technique as well as thermocouple data are presented for the device under both low and high current conditions. Thermal Characterization is obtained for load currents up to 4 amperes and current densities up to 45A/mm2 in the power arrays. Temperature nonuniformity in the arrays is studied as a function of array size, bias level, and ambient temperature. Increased heating is shown to develop near the source contact region in the arrays.
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High-resolution noncontact Thermal Characterization of semiconductor devices
Metrology-based Control for Micro-Manufacturing, 2001Co-Authors: James Christofferson, Ali Shakouri, Daryoosh Vashaee, Philip MeleseAbstract:Non-contact optical methods can be used for sub micron surface Thermal Characterization of active semiconductor devices. Point measurements were first made, and then real time Thermal images were acquired with a specialized PIN- array detector. This method of Thermal imaging can have spatial resolution better than the diffraction limit of an infrared camera and can work in a wide range of ambient temperatures. The experimentally obtained Thermal resolution is on the order of 50 mK.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Bernard Courtois - One of the best experts on this subject based on the ideXlab platform.
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Thermal Characterization and Modeling of Stacked Die Packages
Advances in Electronic Packaging Parts A B and C, 2005Co-Authors: Péter G. Szabó, Andras Poppe, Marta Rencz, Vladimir Szekely, G. Farkas, Bernard CourtoisAbstract:The main issues in the Thermal Characterization and modeling of stacked die packages are the appropriate model generation, and the qualification of the die attach quality between the different layers of the stacked die structures. The first part of the paper gives a short introduction of stacked die packages. The next chapter describes the main issues of steady state and transient compact model generation for the Thermal behavior of stacked die packages. The third large part of the paper gives an overview of the different methodologies applied today for the quality Characterization of the different die attach layers, as a major indicator of the reliability of the package.Copyright © 2005 by ASME
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A step forward in the transient Thermal Characterization of packages
1997Co-Authors: Vladimir Szekely, Marta Rencz, Bernard CourtoisAbstract:Generating compact dynamic Thermal models is a key issue in the Thermal Characterization of packages. A further but related problem is the modeling of the Thermal coupling between chip locations, for the use in electro-Thermal circuit simulators. The paper presents a measurement based method which provides a way to solve both problems. A Thermal benchmark chip has been designed and realized, to facilitate Thermal transient measurements. The developed evaluation method provides the compact Thermal multiport model of the IC chip including package effects, for the accurate electro-Thermal simulation of the ICs. The evaluation method is also suitable to generate the global compact Thermal model of the package.
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A step forward in the transient Thermal Characterization of packages
1997Co-Authors: V. Szekely, Marta Rencz, Bernard CourtoisAbstract:Generating compact dynamic Thermal models is a key issue in the Thermal Characterization of packages. A further but related problem is the modeling of the Thermal coupling between chip locations, for use in electro-Thermal circuit simulators. The paper presents a measurement based method which provides a way to solve both problems. A Thermal benchmark chip has been designed and realized, to facilitate Thermal transient measurements. The developed evaluation method provides a compact Thermal multiport model of the IC chip including package effects, for accurate IC electro-Thermal simulation. The evaluation method is also suitable for generation of a global compact Thermal model of the package.
Ryan Cochran - One of the best experts on this subject based on the ideXlab platform.
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spectral techniques for high resolution Thermal Characterization with limited sensor data
Design Automation Conference, 2009Co-Authors: Ryan Cochran, Sherief RedaAbstract:Elevated chip temperatures are true limiters to the scalability of computing systems. Excessive runtime Thermal variations compromise the performance and reliability of integrated circuits. To address these Thermal issues, state-of-the-art chips have integrated Thermal sensors that monitor temperatures at a few selected die locations. These temperature measurements are then used by Thermal management techniques to appropriately manage chip performance. Thermal sensors and their support circuitry incur design overheads, die area, and manufacturing costs. In this paper, we propose a new direction for full Thermal Characterization of integrated circuits based on spectral Fourier analysis techniques. Application of these techniques to temperature sensing is based on the observation that die temperature is simply a space-varying signal, and that space-varying signals are treated identically to time-varying signals in signal analysis. We utilize Nyquist-Shannon sampling theory to devise methods that can almost fully reconstruct the Thermal status of an integrated circuit during runtime using a minimal number of Thermal sensors. We propose methods that can handle uniform and non-uniform Thermal sensor placements. We develop an extensive experimental setup and demonstrate the effectiveness of our methods by Thermally characterizing a 16-core processor. Our method produces full Thermal Characterization with an average absolute error of 0.6% using a limited number of sensors.
A. Wixforth - One of the best experts on this subject based on the ideXlab platform.
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Thermal Characterization of Surface Acoustic Wave devices
2013 IEEE International Ultrasonics Symposium (IUS), 2013Co-Authors: C. Huck, H. P. Zidek, T. Ebner, K. C. Wagner, A. WixforthAbstract:Reliability of micro-electronic devices is one of the most important issues in mobile communication systems and is significantly influenced by the Thermal behavior of the components. This study presents different schemes for Thermal Characterization of a half-section ladder-type Surface Acoustic Wave (SAW) filter which is acoustically passivated with a thick SiO2 layer. Unitarity violation quantifies the entire power loss in the device but is unfeasible regarding correlation to each resonator. The Temperature Coefficient of Frequency (TCF) characterizes Thermally induced frequency shifts and has the potential to investigate the resonators' temperatures separately in first order. However, uncertainties arise using this indirect approach as soon as other effects causing a frequency shift play a role. Thermographic techniques such as Infrared Thermography (IRT) and Liquid Crystal Thermography (LCT) serve as direct measurement schemes eliminating inaccuracies inherent to TCF based evaluations and show good agreement with simulation results. Moreover, LCT and IRT provide spatially resolved temperature measurements of the component.
