• 전자통신동향분석
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• 제38권6호
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• pp.41-51
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• 2023

Heat dissipation technology for semiconductors and electronic packaging has a substantial impact on performance and lifespan, but efficient heat dissipation is currently facing limited improvement. Owing to the high integration density in electronic packaging, heat dissipation components must become thinner and increase their performance. Therefore, heat dissipation materials are being devised considering conductive heat transfer, carbon-based directional thermal conductivity improvements, functional heat dissipation composite materials with added fillers, and liquid-metal thermal interface materials. Additionally, in heat dissipation structure design, 3D printing-based complex heat dissipation fins, packages that expand the heat dissipation area, chip embedded structures that minimize contact thermal resistance, differential scanning calorimetry structures, and through-silicon-via technologies and their replacement technologies are being actively developed. Regarding dry cooling using single-phase and phase-change heat transfer, technologies for improving the vapor chamber performance and structural diversification are being investigated along with the miniaturization of heat pipes and high-performance capillary wicks. Meanwhile, in wet cooling with high heat flux, technologies for designing and manufacturing miniaturized flow paths, heat dissipating materials within flow paths, increasing heat dissipation area, and reducing pressure drops are being developed. We also analyze the development of direct cooling and immersion cooling technologies, which are gradually expanding to achieve near-junction cooling.

• Corrosion Science and Technology
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• 제19권1호
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• pp.23-30
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• 2020

Heat sinks are most widely used in thermal management systems; however, the heat dissipation efficiency is usually limited. Therefore, in order to increase heat dissipation efficiency of the heat sink, the heat-dissipating paint using 2D materials (hexagonal boron nitride (h-BN) and graphene) as thermally conductive additive was designed and evaluated in the present study. The heat dissipation performance of the paint was calculated from temperature difference between the paint-coated and -uncoated specimens mounted on the heat source. The highest heat dissipation performance was obtained when the ratio of h-BN to resin was 1/10 in the paint. In addition, further reduction in the temperature of the test specimen by 6.5 ℃ was achieved. The highest heat dissipation performance of the paint prepared using graphene was achieved at a 1/50 ratio of graphene to the resin, and a 6.5 ℃ reduction was attained. In addition, graphene exhibited enhanced corrosion resistance property of heat-dissipating paint by inhibiting the growth of the paint blisters.

• 한국전기전자재료학회논문지
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• 제28권2호
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• pp.137-141
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• 2015

The purpose of this study is examining thermal dissipation materials for the lighting and radiate efficiency improvement of 8W LED and confirming the properness of the thermal dissipation materials for LED heat sink. Solid Works flow simulation on 8W class COB was done based on the material characteristics of thermal conductive polymer materials. According to the result of simulation, Al had better thermal dissipation performance than PET. Highest temperature was $7.6^{\circ}C$ higher while lowest temperature was $7.8^{\circ}C$ lower. The test on the heat sinks made by the materials, highest temperature was $4.1^{\circ}C$ higher and lowest temperature was $3.9^{\circ}C$ lower. It is possible to confirm that Al heat sink has better thermal dissipation efficiency because it has better dispersion of heat generated at junction temperature and less heat cohesion. The weight of PET heat sink was reduced than Al heat sink by 46.9% by the density difference between Al and PET. In conclusion, thermal dissipation performance of thermal conductive polymer is lower than Al material however, it is possible to lighting heat sink because thermal conductive polymer has better formability, has lower specific weight and enables various design options.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2061-2066
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• 2007

Recently, ultra-lightweight materials with open, periodic cell structures take much attention owing to its potential for multi-functionality such as load bearing, thermal dissipation, and actuation. This paper presents experimental results on the hydraulic and heat transfer characteristics for the Wire-woven Bulk Kagome(WBK) composed of aluminum 1100 wires. The overall pressure drop and heat transfer of the WBK specimen have been experimentally investigated under forced air convection condition. The pressure loss and heat transfer performance of the aluminum WBK are compared with other heat dissipation media. It was shown that heat transfer depended on relative density and surface area density. Comparison with metal foams and other heat dissipation media such as packed beds, lattice frame materials, louvered fins, and other materials suggests that the aluminum WBK competes favorably with the best available heat dissipation media in heat transfer performance.

• 대한전기학회논문지
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• 제45권4호
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• pp.553-557
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• 1996

Heat cycle aging of insulating materials in large generator stator winding has been investigated using both on-line and off-line test methods. On this study, principally, off-line test against actual generator in service was carried out to acquire information about polarization index(PI) and dissipation factor, dissipation factor tip-up, maximum partial discharge for the purpose of remnant breakdown voltage and life assessment. It was found from the tests that both dissipation factor and maximum partial discharge decreased with the increase of operating hours and starting numbers. It was found from off-line tests that the remnant breakdown voltage had a strong relationship with both dissipation factor and maximum partial discharge the remnant breakdown voltage as a results of both operating hours and starting number and the nondestructive tests were proposed as parameters which can predict the remnant lifetime of insulating materials in large generator stator windings. (author). 8 refs., 8 figs., 2 tabs.

• Design & Manufacturing
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• 제13권3호
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• pp.24-28
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• 2019

In this study, a study was carried out that could effectively produce a heat dissipation effect on plastic materials. Using carbon nanotube (CNT), aluminum powder and plastic, the material properties were tested in 2 cases of compounding ratio. The test sample mold was designed and constructed prior to the experiment. The experiments include tensile strength, elongation rate, flexural strength, flexural elasticity rate, eye-jaw impact strength, gravity and thermal conductivity. Results from 60% and 70% mixture of aluminium to plastic were tested, and a 10% less combined result was a relatively good property. For research purposes, the heat dissipation effect and light weighting obtained a good measure when the combined amount of Al was 60%.

• Design & Manufacturing
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• 제13권3호
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• pp.6-10
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• 2019

In this study, a study was carried out that could effectively produce a heat dissipation effect on plastic materials. Using carbon nanotube (CNT), aluminum powder and plastic, the material properties were tested in 2 cases of compounding ratio. The test sample mold was designed and constructed prior to the experiment. The experiments include tensile strength, elongation rate, flexural strength, flexural elasticity rate, eye-jaw impact strength, gravity and thermal conductivity. Results from 60% and 70% mixture of aluminium to plastic were tested, and a 10% less combined result was a relatively good property. For research purposes, the heat dissipation effect and light weighting obtained a good measure when the combined amount of Al was 60%.

• 대한기계학회논문집B
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• 제32권1호
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• pp.15-22
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• 2008

Recently, ultra-lightweight materials with open, periodic cell structures take much attention owing to its potential for multi-functionality such as load bearing, thermal dissipation, and actuation. This paper presents experimental results on the fluid flow and heat transfer characteristics for the Wire-woven Bulk Kagome (WBK) composed of aluminum 1100 wires. The overall pressure drop and heat transfer of the WBK specimen was experimentally investigated under forced air convection condition. The pressure loss and heat transfer performance of the aluminum WBK were compared with other heat dissipation media. It was shown that heat transfer characteristics depended on relative density and surface area density. Comparison with metal foams and other heat dissipation media such as packed beds, lattice frame materials, louvered fins, and others suggests that the aluminum WBK competes favorably with the best available heat dissipation media in heat transfer performance.

• 한국전기전자재료학회논문지
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• 제36권6호
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• pp.633-637
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• 2023

Recently, with the development of the smart device market, the integration of high-functional devices has increased the heat density, causing overload of the device, and resulting in various problems such as shortened lifespan, performance degradation, and failure. Therefore, research on heat dissipation materials is being actively conducted to realize next-generation electronic products. The heat dissipation material is characterized in that it is easy to dissipate heat due to its high thermal conductivity and minimizes leakage current flowing through the heat dissipation material due to its low electrical conductivity. In this study, flower-shaped Al₂O₃ and BN composites were engineered with a simple hydrothermal synthesis approach, and their thermal conductivity characteristics were compared and evaluated for each synthesis condition for the application to a heat dissipation material. Spherical BN and flower-shaped Al₂O₃ were easily obtained, and SEM/EDS analyses confirmed the uniform presence of BN between the Al₂O₃, and it can be expected that these shapes can affect the thermal conductivity.

• 한국표면공학회지
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• 제56권1호
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• pp.55-61
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• 2023

As a preliminary study to produce functional nanocomposites in a heat dissipation device, we performed the direct synthesis of carbon nanotubes (CNTs) on the surface of alumina (Al₂O₃) powders. A thermal chemical vapor deposition (TCVD) system was used to grow CNTs directly on the Al₂O₃ surface. In order to investigate the growth behavior of CNTs, we varied both furnace temperature of the TCVD ranging from 700 to 850 ℃ and concentration of the ferritin-dissolved DI solution from 0.1 to 2.0 mg/mL. From the previous results, the gas composition and duration time for CNT growth were fixed as C₂H₄ : H₂ = 30 : 500 (vol. %) and 10 min, respectively. Based on the analysis results, the optimized growth temperature and ferritin concentration were found to be 825 ℃ and 0.5 mg/mL, respectively. The obtained results could be adopted to achieve mass production of nanocomposites with heat dissipation functionality.