We investigated the thermal performance of a power semiconductor module used in mobile communication systems. The module contained hetero-junction bipolar transistor (HBT) fingers, which were fabricated on the top of a semiconductor substrate. We calculated the thermal resistance between the HBT fingers and the bottom surface of a multi-layer printed circuit board (PCB) using a finite element m...

A transient thermoreflectance technique, using a 200-fs laser pulse, is demonstrated as a nondestructive method for measuring the thermal boundary resistance between a thin metallic film and dielectric substrate. Experimental results are presented for Au deposited on silicon and silicon dioxide substrates taken at room temperature and compared to a thermal model. The relevant thermal properties...

High-temperature thermal contact resistance (TCR) plays an important role in heat-pipe-cooled thermal protection structures due to the existence of contact interface between the embedded heat pipe and the heat resistive structure, and the reduction mechanism of thermal contact resistance is of special interests in the design of such structures. The present paper proposed a finite element model ...

MODELING THE EFFECT OF WATER ACTIVITY ON THERMAL RESISTANCE OF SALMONELLA IN WHEAT FLOUR By Danielle F. Smith Salmonella is able to survive in low-moisture environments, is known to be more heat resistant as product water activity decreases, and recently has been implicated in several outbreaks and/or recalls associated with low-moisture foods. Therefore, the specific objectives were to: (1) Ev...

Three-Phase Fluidized Beds have found an important place in processing technology as Reactors. Gas-Liquid-Solid fluidization is considered in the present paper as operating bed of fluidized solid particles simultaneously with co-current upward flow of a continuous liquid phase and a gaseous phase dispersed in the form of bubbles. In the present study, the experimental work of the author on heat...

Transient thermography employs preheated surface temperature variations caused by delaminations, cracks, voids, corroded regions, etc. Often, it is enough to detect these changes to declare a defect in a workpiece. It is also desirable to obtain additional information about the defect from the thermal response. The planar size, depth, and thermal resistance of the detected defects are the param...

0017-9310/$ see front matter 2009 Elsevier Ltd. A doi:10.1016/j.ijheatmasstransfer.2009.12.007 * Corresponding author. E-mail address: [email protected] (K. Vafai). Analytical models are utilized to investigate the thermal performance of rectangular and disk-shaped heat pipes using nanofluids. The liquid pressure, liquid velocity profile, temperature distribution of the heat pipe wall, tempera...

Abstract—The aim of this paper is to present a parametric study to determine the major factors that influence the calculations of current rating for both air and underground cables. The current carrying capability of the power cables rely largely on the installation conditions and material properties. In this work, the influences on ampacity of conductor size, soil thermal resistivity and ambie...

Silver sintering joints and AuGe soldering are promising technologies for high temperature (>200 C ambient) power electronics packaging. This paper presents the implementation of two silver-sintering processes with the one hand micrometer-scale silver particles, and on the other hand nano-meter-scale particles. Two substrates technologies have been investigated: A12O3 DBC and Si3N4 AMB. After t...