• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.1092-1095
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• 2001

Steady state thermal analysis has been done by a finite element method in a diode of 12kV blocking voltage. The diode was fabricated by soldering ten pieces of 1200V diodes in series, capping a dummy wafer at the far end of diode series, and finally wire bonded for building anode and cathode terminal. In order to achieve high voltage and reliability, the edge of each diode was beveled and passivated by resin with a thickness of 25${\mu}$m. It was assumed that the generated heat which is mainly by the on-state voltage drop, 9V for 12kV diode, is dissipated by way of the conduction through diodes layers to bonding wire and of the convection at the surface of passivating resin. It was predicted by the thermal analysis that the temperature rise of a pn junction of the 12kV diode can reach at the range of 16∼34$^{\circ}C$ under the given boundary conditions. The thickness and thermal conductivity(0.3∼3W/m-K) of the passivating resin did little effect to lower thermal resistance of the diode. As the length of the bonding wire increased, which means the distance of heat conduction path became longer, the thermal resistance increased considerably. The thermal analysis results imply that the generated heat of the diode is dissipated mainly by the conduction through the route of diode-dummy wafer-bonding wire, which suggests to minimize the length of the wire for the lowest thermal resistance.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.205-208
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• 2001

Steady state and transient thermal analysis has been done by a finite element method in a diode of 12kV blocking voltage for microwave oven. The diode was fabricated by soldering ten pieces of 1200V diodes in series, capping a dummy wafer at the far end of diode series, and finally copper wire bonded for building anode and cathode terminal. In order to achieve high voltage and reliability, the edge of each diode was beveled and passivated by resin and epoxy with a thickness of $25{\mu}m$ and $3700{\mu}m$, respectively. The chip size, thickness and material properties were very important factor for high voltage diode package. And also, thermal stress value was highest in the edge of diode and solder. So, design of edge in silicon was very important to thermal stress.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.205-208
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• 2001

Steady state and transient thermal analysis has been done by a finite element method in a diode of 12kV blocking voltage for microwave oven. The diode was fabricated by soldering ten pieces of 1200V diodes in series, capping a dummy wafer at the far end of diode series, and finally copper wire bonded for building anode and cathode terminal. In order to achieve high voltage and reliability, the edge of each diode was beveled and passivated by resin and epoxy with a thickness of 25$\mu\textrm{m}$ and 3,700$\mu\textrm{m}$, respectively. The chip size, thickness and material properties were very important factor for high voltage diode package. And also, thermal stress value was highest in the edge of diode and solder. So, design of edge in silicon was very important to thermal stress.

• Journal of the Korean Vacuum Society
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• v.21 no.4
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• pp.185-192
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• 2012

p-n junction temperature and thermal resistance of Light Emitting Diode (LED) package are affected by the chip size due to the change of the thermal density and the external quantum efficiency considering the heat dissipation through conduction. In this study, forward voltage was measured for two different size LED chips, 24 mil and 40 mil, which consist constitute 16-chip package. p-n junction temperature and thermal resistance were determined by thermal transient analysis, which were discussed in connection with the electrical characteristics of the LED chip and the structure of the LED package.

• Structural Engineering and Mechanics
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• v.53 no.4
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• pp.645-659
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• 2015

This research investigates the thermoelastic transient behavior of a thermally loaded slab made of a thermal diode-like material which has two directional thermal conductivity values (low and high). Finite difference analysis is used to obtain the elastic response of the slab based on the temperature solutions. It is found that the rate of heat transfer through the thickness of the slab decreases with reducing the ratio between the low and high thermal conductivity values (R). In addition, reducing R makes the slab less responsive to the thermal load when heated from the direction associated with the low thermal conductivity value.

• Current Optics and Photonics
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• v.1 no.2
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• pp.113-117
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• 2017

With the increasing use of high-power laser diode bars (LDBs) and stacked LDBs, the issue of thermal control has become critical, as temperature is related to device efficiency and lifetime, as well as to beam quality. To improve the thermal resistance of an LDB set, we propose and analyze a bypass heat sink with a top canopy structure for an LDB set, instead of adopting a thick submount. The thermal bypassing in the top-canopy structure is efficient, as it avoids the cross-sectional thermal saturation that may exist in a thick submount. The efficient thickness range of the submount in a typical LDB set is guided by the thermal resistance as a function of thickness, and the simulated bypassing efficiency of a canopy is higher than a simple analytical prediction, especially for thinner canopies.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.208-212
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• 2003

Silicon transient voltage suppressors (TVSs) are clamping devices that limit voltage spikes by low impedance avalanche breakdown of a rugged silicon PN junction. They are used to protect sensitive components from electrical overstress such as that caused by induces lightning, inductive load switching and electrostatic discharge. In this paper, we present static and dynamic characteristics of TVS diode using thermal analysis simulation software. And also, it is presented that the thermal dissipation characteristics of TVS diode in the transient state.

• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.79-81
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• 1990

Temperature distribution of laser diode chip mounted on ideal heat kink was calculated by numerical analysis. In numerical analysis, infinite difference method and Gauss-Scidel iteration was adopted on the basis of two dimensional heat conduction phenomena. As a result, temperature increase of active medium of laser diode driven at 60mA was calculated to be 1.47$^{\circ}C$

• Journal of the Korean Solar Energy Society
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• v.35 no.4
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• pp.67-75
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• 2015

PV module is conventionally connected in series with some solar cell to adjust the output of module. Some bypass diodes in module are installed to prevent module from hot spot and mismatch power loss. However, bypass diode in module exposed outdoor is easily damaged by surge voltage. In this paper, we study the thermal and electrical characteristics change of module with damaged bypass diode to easily find module with damaged bypass diode in photovoltaic system consisting of many modules. Firstly, the temperature change of bypass diode is measured according to forward and reverse bias current flowing through bypass diode. The maximum surface temperature of damaged bypass diode applied reverse bias is higher than that of normal bypass diode despite flowing equal current. Also, the output change of module with and without damaged bypass diode is observed. The output of module with damaged bypass diode is proportionally reduced by the total number of connected solar cells per one bypass diode. Lastly, the distribution temperature of module with damaged bypass diode is confirmed by IR camera. Temperature of all solar cells connected with damaged bypass diode rises and even hot spot of some solar cells is observed. We confirm that damaged bypass diodes in module lead to power drop of module, temperature rise of module and temperature rise of bypass diode. Those results are used to find module with a damaged bypass diode in system.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2004.11a
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• pp.30-30
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• 2004