Two-Wavelength Thermoreflectance and its Application in Temperature Measurement of Micro-Electronic Devices

2018 ◽  
Author(s):  
Hongjie Zhang ◽  
Sy-Bor Wen
Keyword(s):  
Thermal Expansion ◽  
Steady State ◽  
Temperature Measurement ◽  
Imaging Technique ◽  
Electronic Devices ◽  
Target Movement ◽  
Steady State Operation ◽  
Steady State Temperature ◽  
Higher Temperature ◽  
Low Sensitivity

A two-wavelength thermoreflectance (2WTR) imaging technique is developed to conduct steady-state temperature measurement of miniature electronic devices, such as micro-scale gold resistors. Compared with traditional single wavelength thermoreflectance (TR) imaging requiring comparison of TR signals from a target under heated and unheated conditions, 2WTR method obtains temperature information from heated target under operation directly. Therefore, 2WTR is not affected by movement of a heated target due to thermal expansion. Note that thermal expansion of targets between heated and unheated conditions is a main constraint of current TR imaging of miniature targets. In addition to the low sensitivity to the target movement, the new 2WTR can provide even higher temperature resolution than single wavelength TR by appropriately selecting the adopted two wavelength to have different signs of TR coefficients. With this new TR imaging technique, we successfully measure temperature distribution of a microscale gold resistor under steady-state operation, which are challenging to be obtained by traditional single wavelength TR method.

Memory test system for piston steady-state temperature measurement

2017 ◽  
Vol 110 ◽  
pp. 436-441
Author(s):  
Hui Dai ◽  
Ronghua Huang ◽  
Guiquan Li ◽  
Jie Tang ◽  
Sheng Huang
Keyword(s):  
Steady State ◽  
Temperature Measurement ◽  
Test System ◽  
Memory Test ◽  
Steady State Temperature

scholarly journals Physics of ferroelectric differential capacitance based upon free energy, and implications for use in electronic devices

2019 ◽  
Vol 09 (01) ◽  
pp. 1950002
Author(s):  
C. M. Krowne
Keyword(s):  
Free Energy ◽  
Steady State ◽  
Millimeter Wave ◽  
Electronic Devices ◽  
Strain Engineering ◽  
Differential Capacitance ◽  
Stable Steady State ◽  
Stable Operation ◽  
Steady State Operation

In this paper, it is shown that for stable, steady state operation of devices typical of microwave and millimeter wave electronics, no negative differential capacitance is possible with conventional thinking. However, it may be possible, with strain engineering of materials, to obtain some if not all elements of the differential capacitance tensor which are negative. Rigorous derivations are provided based upon analyzing the physics using thermodynamic phenomenological free energy. It should be emphasized that, even with strain engineering, and possible discovery of some negative capacitive elements, stable operation will not be obtained because the thermodynamics precludes it.

The Effect of Non-Steady Temperatures on Experimental Investigations of Flow Instability between Eccentric Rotating Cylinders

1979 ◽  
Vol 21 (3) ◽  
pp. 215-217
Author(s):  
P. H. Markho ◽  
F. R. Mobbs
Keyword(s):  
Steady State ◽  
Temperature Measurement ◽  
Flow Instability ◽  
Quantitative Agreement ◽  
Research Area ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Fluid Temperature ◽  
General Lack ◽  
Steady State Operation

Non-steady-state operation makes it very difficult to measure the actual, ‘controlling’ fluid temperature sufficiently accurately. This effect has been quantified and shown to be significant for discrepancies in temperature measurement greater than 0.5 K. A method for correction has also been suggested and verified. It is tempting to speculate, on the basis of this study, that the general lack of quantitative agreement among experimental results of previous investigators in this research area may have been partly caused by thermal inadequacies in apparatus or procedure.

scholarly journals Series Compensation of Transmission Systems: A Literature Survey

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1717
Author(s):  
Camilo Andrés Ordóñez ◽  
Antonio Gómez-Expósito ◽  
José María Maza-Ortega
Keyword(s):  
Steady State ◽  
Power Systems ◽  
Power System ◽  
Case Studies ◽  
Electronic Devices ◽  
Literature Survey ◽  
Power Electronic ◽  
Transmission Systems ◽  
Series Compensation ◽  
Near Future

This paper reviews the basics of series compensation in transmission systems through a literature survey. The benefits that this technology brings to enhance the steady state and dynamic operation of power systems are analyzed. The review outlines the evolution of the series compensation technologies, from mechanically operated switches to line- and self-commutated power electronic devices, covering control issues, different applications, practical realizations, and case studies. Finally, the paper closes with the major challenges that this technology will face in the near future to achieve a fully decarbonized power system.

scholarly journals Identification of DC Thermal Steady-State Differential Inductance of Ferrite Power Inductors

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3854
Author(s):  
Salvatore Musumeci ◽  
Luigi Solimene ◽  
Carlo Stefano Ragusa
Keyword(s):  
Steady State ◽  
Input Voltage ◽  
Switching Frequency ◽  
Ohmic Losses ◽  
Steady State Temperature ◽  
Wide Range ◽  
Average Current ◽  
Power Inductors ◽  
Saturable Inductor ◽  
Thermal Steady State

In this paper, we propose a method for the identification of the differential inductance of saturable ferrite inductors adopted in DC–DC converters, considering the influence of the operating temperature. The inductor temperature rise is caused mainly by its losses, neglecting the heating contribution by the other components forming the converter layout. When the ohmic losses caused by the average current represent the principal portion of the inductor power losses, the steady-state temperature of the component can be related to the average current value. Under this assumption, usual for saturable inductors in DC–DC converters, the presented experimental setup and characterization method allow identifying a DC thermal steady-state differential inductance profile of a ferrite inductor. The curve is obtained from experimental measurements of the inductor voltage and current waveforms, at different average current values, that lead the component to operate from the linear region of the magnetization curve up to the saturation. The obtained inductance profile can be adopted to simulate the current waveform of a saturable inductor in a DC–DC converter, providing accurate results under a wide range of switching frequency, input voltage, duty cycle, and output current values.

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