• 한국전자통신학회논문지
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• 제9권12호
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• pp.1435-1440
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• 2014

본 논문에서는 13.2W급 COB LED의 공랭식 방열을 위해 열전소자를 이용하여 열적 특성을 분석하였다. 기존 방식과의 방열 성능을 비교 분석하기 위하여 Heat Sink를 설계 및 제작 하였고 실험은 100분간 COB LED를 구동시켜 접촉식 온도계를 통하여 온도 분포를 측정하였다. 접합부의 온도 측정 결과 열전소자를 사용하지 않는 방식에서는 약 $75^{\circ}C$로 나타났고, 열전소자에 0.8A의 전류를 인가하여 구동하였을 때 $57^{\circ}C$로 열 응집현상이 가장 심한 COB LED 접합부분의 열은 기존의 방식보다 약 31% 감소됨을 확인하였다.

• 대한금속재료학회지
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• 제56권11호
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• pp.805-812
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• 2018

High pressure die casting is one of the precision casting methods. It is highly productivity and suitable for manufacturing components with complex shapes and accurate dimensions. Recently, there has been increasing demand for efficient heat dissipation components, to control the heat generated by devices, which directly affects the efficiency and life of the product. Die cast aluminum alloys with high thermal conductivity are especially needed for this application. In this study, the influence of elements added to the die cast aluminum alloy on its thermal conductivity was evaluated. The results showed that Mn remarkably deteriorated the thermal conductivity of the aluminum alloy. When Cu content was increased, the tensile strength of cast aluminum alloy increased, showing 1 wt% of Cu ensured the minimum mechanical properties of the cast aluminum. As Si content increased, the flow length of the alloy proportionally increased. The flow length of aluminum alloy containing 2 wt% Si was about 85% of that of the ALDC12 alloy. A heat dissipation component was successfully fabricated using an optimized composition of Al-1 wt%Cu-0.6 wt%Fe-2 wt%Si die casting alloy without surface cracks, which were turned out as intergranular cracking originated from the solidification contraction of the alloy with Si composition lower than 2 wt%.

• Composites Research
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• 제35권3호
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• pp.175-181
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• 2022

무선통신기술의 발전과 함께 통신기기의 활용영역은 기하급수적으로 증가하고 있으며, 이에 따라 통신기기 성능의 저하를 막기 위한 전자파 노이즈 간섭문제 해결 및 방열문제 해결 소재에 대한 관심이 높아지고 있다. 본 연구에서는 전자파 차폐와 우수한 방열특성을 동시에 가질 수 있는 복합소재 필름을 제안하였다. 이 필름은 고분자 수지에 자성 및 방열 필러 물질이 분산된 복합소재 레이어와 전도성 그리드로 구성되어 있다. 복합소재 레이어의 조성 및 특성에 대한 제어 및 전도성 그리드 형상에 대한 설계를 통해 높은 전자파 차폐능(>40 dB), 낮은 전자파 반사능(<3 dB), 우수한 열전도도(>10 W/m·K)를 5G 통신 대역인 26.5 GHz에서 500 ㎛ 이하의 극박 필름으로 달성하는 데 성공하였다.

• 반도체디스플레이기술학회지
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• 제21권1호
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• pp.148-154
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• 2022

As the 4th industrial age approaches, the demand for semiconductors is increasing enough to be used in all electronic devices. At the same time, semiconductor technology is also developing day by day, leading to ultraprecision and low power consumption. Semiconductors that keep getting smaller generate heat because the energy density increases, and the generated heat changes the shape of the semiconductor package, so it is important to manage. The temperature change is not only self-heating of the semiconductor package, but also heat generated by external damage. If the package is deformed, it is necessary to manage it because functional problems and performance degradation such as damage occur. The package burn in test in the post-process of semiconductor production is a process that tests the durability and function of the package in a high-temperature environment, and heat dissipation performance can be evaluated. In this paper, we intend to review a new material formulation that can improve the performance of the adapter, which is one of the parts of the test socket used in the burn-in test. It was confirmed what characteristics the basic base showed when polyamide, a high-molecular material, and alumina, which had high thermal conductivity, were mixed for each magnification. In this study, functional evaluation was also carried out by injecting an adapter, a part of the test socket, at the same time as the specimen was manufactured. Verification of stiffness such as tensile strength and flexural strength by mixing ratio, performance evaluation such as thermal conductivity, and manufacturing of a dummy device also confirmed warpage. As a result, it was confirmed that the thermal stability was excellent. Through this study, it is thought that it can be used as basic data for the development of materials for burn-in sockets in the future.

• 한국재료학회지
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• 제14권11호
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• pp.775-779
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• 2004

For improvement of heat dissipation performance, heat analysis is conducted on the newly designed heat sinks under two convection conditions by using computational fluid dynamics(CFD). Three types of heat sink, plate, wave and top vented wave, are used, and convection conditions are the variations of gravity direction at natural convection and of fan location at forced convection. The results of analysis showed that the heat resistances of top vented wave heat sink were $0.17^{\circ}C$/W(forced convection) and $0.48^{\circ}C$/W(natural convection). In the case of natural convection, gravity direction affected heat flow change, and protection against heat performance was superior in case of z-axis gravity direction. Under the forced convection, all the heat sinks revealed superior thermal characteristics in the fan position of z-axis rather than y-axis. In this study, it was observed that the top vented wave type heat sink showed the best ability of heat radiation comparing with the others.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.182-187
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• 2006

This research presented the heat resistance characteristics of heat sink which is newly designed through the experiment. For the same volume and base plate of heat sinks, the experiment of heat transfer characteristics was conducted for forced convection of layered type heat sink. The heat transfer and pressure drop characteristics of the layered type heat sink were compared for the various kinds of fin pitches, fin heights and heights of heat sink. The results show that thermal resistance is decreased as the height of heat sink increases and the fin height and fin pitch decrease, From the experimental data of layered type heat sink, the correlation equation of Nusselt number was obtained as follows ; $$Nu=0.845{\cdot}Re^{0.393}{\cdot}(\frac{f_h}{D_h})^{0.160}{\cdot}(\frac{f_p}{D_h})^{0.372}{\cdot}(\frac{H_{hs}}{D_h})^{-0.942}$$

• 한국산학기술학회논문지
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• 제22권3호
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• pp.415-421
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• 2021

본 연구는 절연 게이트 양극성 트랜지스터 모듈의 히트 싱크의 유로의 형상으로써 직선 유로, 한 번 꺾인 형태의 유로, 두 번 꺾인 형태의 유로를 적용하여, 유로의 형상에 따른 방열 성능을 분석하였다. 각 유로 형상에서 운전 조건에 대한 영향 또한 분석하기 위하여 냉각수의 유량과 공급 온도를 추가적으로 제어하며 분석을 진행하였다. 본 연구는 유동 해석을 통하여 이루어 졌으며, 상용 소프트웨어인 ANSYS Fluent를 사용하였다. 직선 유로보다 꺾인 형태를 갖는 유로의 방열량이 같은 운전 조건에서 최대 8.0 % 수준 개선되었으며, 개선 정도는 냉각수의 공급 온도와는 무관하였고, 냉각수의 유량이 많아질수록 개선 정도가 2.0 %에서 8.0 %까지 증가하였다. 그러나 두 번 꺾인 유로는 한 번 꺾인 유로와 비슷한 수준의 방열 성능을 보였고, 기생 손실에 영향을 주는 압력 강하량은 2.48~2.55배 수준으로 증가하는 결과를 보여, 방열 효율이 낮아지는 것을 확인 하였다. 이를 단위 압력 강하량 당 방열량으로 계산하여 비교하였으며, 직선 유로를 갖는 히트 싱크에서 그 값이 가장 높은 것을 확인하였다.

• 동력기계공학회지
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• 제5권3호
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• pp.48-55
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• 2001

In many applications. rubber components undergo dynamic stresses or deformations of fairly large magnitude. Since rubbers are not fully elastic, a part of the mechanical energy is converted into heat due to the hysteresis loss. Heat generation without adequate heat dissipation leads to heat build up. i. e. internal temperature rise. The purpose of this paper is to predict temperature rise caused by the hysteresis loss, in a rubber pad subjected to complex dynamic deformation. In this unsteady thermal analysis, the temperature distributions of track components are displayed in contour shapes and the temperature variations of some important nodes are represented graphically with respect to the running time of the tank.

• 대한수학회보
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• 제20권2호
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• pp.99-103
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• 1983

Internal heat generation is one of the insidious conditions affecting the quality of an industrial product after it is cast, coated, molded, forged or laminated. Frequently, the product is pressed into service before the exothermic chemical reactions in the generic material has been completed. The heat liberated from this continuing chemical reaction or the residual deformation from the rheological activities in the materials must be adequately removed or prevented, or the product may be discolored, warped, weakened or even "ignited" spontaneously. Numerous instances of premature structural failures, product-recalls, and/or system-malfunctions have been recorded in recent history. The Coulee Dam was poured with pre-chilled concrete just to negate this freakish encore. It is well-known that concrete (a non-isotropic conducting medium), for instance, takes 28 days to develop its full strength. During this period of curing it is conceivable that the processes of internal heat generation, heat conduction and heat dissipation take place simultaneously inside the medium.he medium.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.522-524
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• 2005

The LED light source has many excellent advantages for the application of LCD backlight module. As we know, the operational temperature can significantly influence the characteristics of LEDs. Heat can damage the LED 's quality, and decrease its lifetime and output light intensity. In this paper, we perform computer software, Flomerics CFD (Computational Fluid Dynamics), to simulate heat distribution of the 20.1" LED backlight module we designing, and realize how the different heat sinks can solve the serious heat problem in practice.