• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.3
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• pp.356-364
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• 2015

The transmission performance of TSV considering the effect of electronic-thermal coupling is an new challenge in three dimension integrated circuit. This paper presents the thermal equivalent circuit (TEC) model of the TSV, and discussed the thermal equivalent parameters for TSV. Si layer is equivalent to transmission line according to its thermal characteristic. Thermal transient response (TTR) of TSV considering electronic-thermal coupling effects are proposed, iteration flow electronic-thermal coupling for TSV is analyzed. Furthermore, the influences of TTR are investigated with the non-coupling and considering coupling for TSV. Finally, the relationship among temperature, thickness of $SiO_2$, radius of via and frequency of excitation source are addressed, which are verified by the simulation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.1
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• pp.27-32
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• 2014

In this paper, PZT piezoelectric ceramic specimens with 4 compositions (Zr/Ti=50/50, 53/47, 56/44, 58/42) in $Pb(Zr,Ti)O_3$ system were fabricated. We studied effects of poling strength and thermal aging on the temperature characteristics of eletromechanical coupling factor k31 of the specimens, which were poled with the DC electric fields, 1.5, 2.5 and 3.5 kV/mm respectively and thermally aged for an hour at $200^{\circ}C$. The eletromechanical coupling factor k31 of the specimen with the composition Zr/Ti= 53/47, nearest to the morphotropic phase boundary decreased the most greatly, irrelevant to the intensity of poling field, due to 1st thermal aging. And the temperature coefficient of eletromechanical coupling factor k31 was (-) in the tetragonal phase composition and (+) in the rhombohedral phase composition, which is reverse in the temperature coefficient of resonance frequency. It is interesting that eletromechanical coupling factor k31 of PZT ceramics is shown to be able to increase as temperature increase in the interval $-20{\sim}80^{\circ}C$.

• Journal of Electrical Engineering and Technology
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• v.4 no.2
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• pp.249-254
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• 2009

This article deals with the analysis of a coupling between stationary Maxwell's equations, the transient state Navier-Stokes and thermal equations. The resolution of these equations is obtained by introducing the magnetic vector potential A, the vorticity ${\xi}$, the stream function ${\psi}$ and the temperature T. The flux density, the electromagnetic thrust, the electric power density, the velocity, the pressure and the temperature are graphically visualized. Also, the influence of the frequency is presented.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.10
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• pp.779-785
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• 2012

The epoxy/micro-and nano-mixed silica composites(EMNC) systems were prepared and the AC insulation breakdown strength was evaluated. Glass transition temperature (Tg) and crosslink density were also measured by dynamic mechanical analyzer(DMA) in order to correlate them with the electrical and mechanical properties, and the effect of silane coupling agent on the electrical properties was also studied. Electrical properties and crosslink density of epoxy/micro-silica composite were noticeably improved by addition of nano-silica and silane coupling agent, and the highest breakdown strength was obtained by addition of 0.5~5 phr of nano-silica and 2.5 phr of silane coupling agent, and the highest tensile and flexural strength were obtained by addition of 2.5 phr of nano-silica.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.1002-1006
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• 2015

In this paper, design and analysis of permanent magnet synchronous generator for ocean thermal energy conversion (OTEC) considering magnetically coupled turbine-rotor system is discussed. In particular, the rotor dynamics considering bearing span and journal shaft diameter is highlighted. The two topologies of permanent magnet synchronous generator with magnetic coupling are employed for comparison of computed rotor dynamics and generating characteristics. The analysis results show that the critical speed of the turbine-rotor system is higher when the rotor is coupled by magnetically coupling. Finally, the experimental results confirmed the validity of the proposed design and analysis scheme and successful development.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.7 s.166
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• pp.1085-1093
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• 1999

Thickness effects of coupling agent on residual bending stress were investigated in $Polyimide/SiO_2$ joints during thermal cycling. Thickness and peel strength of $\gamma$-APS coupling agent were measured and correlated with solution concentration and residual bending stress. The variation of residual bending stress with temperature was also measured for various thicknesses of the coupling agent. Finite element results were compared with experimental data for residual bending stress in $Polyimide/SiO_2$ joints.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.176.1-176.1
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• 2014

Graphene has attracted an increasing attention due to its extraordinary electronic, mechanical, and thermal properties. Especially, the two dimensional (2D) sheet of graphene with an extremely high surface to volume ratio has a great potential in the preparation of multifunctional nanomaterials, as 2D supports to host metal nanoparticles (NPs). Copper oxide is widely used in various areas as antifouling paint, p-type semiconductor, dry cell batteries, and catalysts. Although the copper oxide(II) has been well known for efficient catalyst in C-N cross-coupling reaction, copper oxide(I) has not been highlighted. In this research, CuO and Cu2O nanoparticles (NPs) dispersed on the surface of grapehene oxide (GO) have been synthesized by impregnation method and their morphological and electronic structures have been systemically investigated using TEM, XRD, and XAFS. We demonstrate that both CuO and Cu2O on graphene presents efficient catalytic performance toward C-N cross coupling reaction. The detailed structural difference between CuO and Cu2O NPs and their effect on catalytic performance are discussed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.12
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• pp.1077-1081
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• 2007

Thermal expanded core (TEC) fiber can reduce, being advantaged from thermal diffusion technology, connection loss by expanding the tolerance in relation to axial offset and gap when making optical connection having mode field diameter (MFD) of optical fiber expanded locally. In this paper, TEC fiber fabrication system based on the frame brushing techniques using twin-torch tip was designed and developed in order to maintain a stable thermal diffusion and single-mode when manufacturing TEC fiber. We were able to obtain that varied kinds of TEC fibers of which MFD could have been extended between $20\;{\mu}m$ and $40\;{\mu}m$ by TEC fiber fabrication system. In addition, the characteristic of connection loss was measured by alignment two TEC fibers of which MFD was $30\;{\mu}m$.

• Journal of Sensor Science and Technology
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• v.26 no.5
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• pp.338-341
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• 2017

We have investigated a temperature sensor on a thermal expansion effect of a fused optical fiber coupler. Both side of the fused tapered region of the coupler were fixed on a metal support to induce the high thermal expansion effect. The sensor showed that the peak coupling wavelengths were shifted to shorted wavelength region with increased of environmental temperature. The sensitivity of the sensor was $0.12nm/^{\circ}C$.

• Journal of Power Electronics
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• v.14 no.6
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• pp.1345-1356
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• 2014

The thermal behavior of power modules is an important criterion for the design of cooling systems and optimum thermal structure of these modules. An important consideration for high power and high frequency design is the spacing between semiconductor devices, substrate structure and influence of the boundary condition in the case. This study focuses on the thermal behavior of hybrid power modules to establish a simplified method that allows temperature estimation in different module components without decapsulation. This study resulted in a correction of the junction temperature values estimated from the transient thermal impedance of each component operating alone. The corrections depend on mutual thermal coupling between different chips of the hybrid structure. A new experimental technique for thermal mutual evaluation is presented. Notably, the classic analysis of thermal phenomena in these structures, which was independent of dissipated power magnitude and boundary conditions in the case, is incorrect.