• 한국산업융합학회 논문집
• /
• 제20권2호
• /
• pp.187-194
• /
• 2017

This study examined the validity and reliability of the thermal safety design, in order to maintain the heat generated from integrated circuit (IC) chips in the converter, condenser, resistor, and transistor (which are considered as heat sources for thermoelectric devices with a printed circuit board) below target levels during the process of developing a control board and a main power board. The study analyzed the heat generation and dissipation characteristics of the entire printed circuit board (PCB) model to examine its thermal safety.

• Computers and Concrete
• /
• 제8권4호
• /
• pp.425-443
• /
• 2011

Most previous studies have generally overlooked the contribution of thermal stresses generated within the concrete mass when subjected to microwave heating and reported on pore-pressure as being the dominant cause of surface spalling. Also, the variation in electromagnetic properties of concrete and its effects on the microwave heating process have not been studied in detail. In this paper, finite element modeling is used to examine the simultaneous development of compressive thermal stresses and pore-pressure arising from the microwave heating of concrete. A modified Lambert's Law formulation is proposed to estimate the microwave power dissipation in the concrete mass. Moreover, the effects of frequency and concrete water content on the concrete heating rate and pattern are investigated. Results show high compressive stresses being generated especially in concrete with a high water content when heated by microwaves of higher frequencies. The results also reveal that the water content of concrete plays a crucial role in the microwave heating process.

• 한국기계가공학회지
• /
• 제18권4호
• /
• pp.41-47
• /
• 2019

The advent of highly integrated, high-power electronics requires low a coefficient of thermal expansion performance to prevent delamination between the heat dissipation material and substrate. This paper reports a preliminary study on the manufacturing technology of gas reaction control composite material, focusing on the prediction of the thermal expansion coefficients of Al-AlN composite materials. We obtained numerical equivalent property values by using finite element analysis and compared the values with theoretical formulas. Al-AlN should become the optimal composite material when the proportion of the reinforcing phase is approximately 0.45.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2010년 춘계학술대회논문집
• /
• pp.416-421
• /
• 2010

The north and south panel of a geostationary satellite are used for radiator panels to reject internal heat dissipation of electronics units and utilize several heat pipe networks to control the temperatures of units and the satellite within proper ranges. The design of these panels is very important and essential at the conceptual design and preliminary design stage so several thousands of nodes of more are utilized in order to perform thermal analysis of panel. Generating a large number of nodes(meshes) of the panel takes time and is tedious work because the mesh can be easily changed and updated by locations of units and heat pipes. Also the detailed panel model can not be integrated into spacecraft thermal model due to its node size and limitation of commercial satellite thermal analysis program. Thus development of a program was required in order to generate detailed panel model, to perform thermal analysis and to make a reduced panel model for the integration to the satellite thermal model. This paper describes the development and the verification of panel thermal analysis program with ist main modules and its main functions.

• 한국항공우주학회지
• /
• 제32권9호
• /
• pp.114-121
• /
• 2004

정지궤도 통신위성 원격측정명령처리기의 기술인증모델 개발을 위하여 기술모델의 열 설계변경 및 해석을 수행하였다. 보드레벨의 소모전력량 측정치와 열주기시험의 결과를 활용하여 기술모텔에 대한 열해석모델을 개발하였다. 발열소자의 열소산 모델링은 인쇄회로기판에 투영된 소자의 footprint를 생성하고 그 표면의 전 영역에 균일하게 열소산량을 가하였다. 열설계변경(안)에 따라 설계변경 후 기술인증수준의 열진공환경에서 소자온도를 예측한 결과, CTU의 모든 소자들의 접합온도는 허용온도 이내로 존재하였다.

• Journal of Advanced Marine Engineering and Technology
• /
• 제40권8호
• /
• pp.686-691
• /
• 2016

This paper employs numerical tools to obtain an optimal thermal design of a heat exchanger with plain-fins. This heat exchanger is located at the condensing section of a crevice-type heat pipe. The plain-fins in the heat exchanger are radically mounted to two tubes in the condensing section. To obtain the optimal design parameters, a computational fluid dynamics technique is introduced and applied to different placement configurations in a system module. Owing to its effects on the heat pipe performance, the temperature difference between the tube surfaces and ambient air is investigated in detail. A greater heat dissipation rate occurs when the plain-fin offsets change from 2 to 3 mm. When this temperature difference is ${\Delta}T=70^{\circ}C$, the upper part of the plain-fins undergoes an accumulation of heat. At below $70^{\circ}C$, the dissipation of heat is accepted. A rectangular plain-fin geometry with varying widths and heights does not have a significant impact on the heat dissipation through-out the overall system. In addition, the temperature distributions between different plain-fin pitches show an equal profile even with different fin pitches.

• 마이크로전자및패키징학회지
• /
• 제20권3호
• /
• pp.75-80
• /
• 2013

전자패키징 기술의 발전에 따라 패키지의 소형화는 집적화에 따른 열 소산 면적 감소로 인하여 패키지의 온도 상승을 초래한다. 온도 상승은 소자의 성능을 저해하여, 시스템 고장을 발생을 유발시키며 수명을 단축시킨다. 본 연구에서는 마이크로 패턴과 세미 임베디드 구조를 결합하여 열 소산을 극대화 시킬 수 있는 새로운 구조를 제안하여 열특성을 평가하였다. 제안 구조의 열특성 평가 결과, 기존 구조에 비하여 최대 온도는 $20^{\circ}C$낮았으며, 범프의 최대 응력은 20%이상 감소하여 제안 구조의 유효성을 확인하였다.

• 한국군사과학기술학회지
• /
• 제22권2호
• /
• pp.249-254
• /
• 2019

A Digital Transmitter/Receiver Module(DTRM), which is an essential part in active phased-array radar systems, generates a high heat density, and needs to be properly cooled for stable operation. A tile-type DTRM that is a stacking structure of multi-layer components was modeled with simplification and heat dissipation characteristics of the DTRM model were studied using computational fluid dynamics(CFD) simulations. Most of the heat was dissipated by the heat conduction through the cold plate, but the heat transfer by the forced convection on top of the DTRM also was found to play an important role in the thermal management. Under the given conjugated heat transfer environment, the DTRM was confirmed to secure a stable operating temperature range.

• Nuclear Engineering and Technology
• /
• 제55권11호
• /
• pp.4173-4180
• /
• 2023

The stability of engineered barriers in high-level radioactive waste disposal systems can be influenced by the decay heat generated by the waste. This study focuses on the thermal analysis of various canister designs to effectively lower the maximum temperature of the engineered barrier. A numerical model was developed and employed to investigate the heat dissipation potential of copper rings placed across the buffer. Various canister designs incorporating copper rings were presented, and numerical analysis was performed to identify the design with the most significant temperature reduction effect. The results confirmed that the temperature of the buffer material was effectively lowered with an increase in the number of copper rings penetrating the buffer. Parametric studies were also conducted to analyze the impact of technical gaps, copper thickness, and collar height on the temperature reduction. The numerical model revealed that the presence of gaps between the components of the engineered barrier significantly increased the buffer temperature. Furthermore, the reduction in buffer temperature varied depending on the location of the gap and collar. The methods proposed in this study for reducing the buffer temperature hold promise for contributing to cost reduction in radioactive waste disposal.

• 한국마이크로전자및패키징학회:학술대회논문집
• /
• 한국마이크로전자및패키징학회 2001년도 3rd Korea-Japan Advanced Semiconductor Packaging Technology Seminar
• /
• pp.121-145
• /
• 2001

Chip Size Packages (CSP) are now widely used in high speed DRAM. The major driving farce of CSP development is its superior electrical performance than that of conventional package. However, the power dissipation of high speed DRAM like DDR or RAMBUS DRAM chip reaches up to near 2W. This fact makes the thermal management methods in DRAM package be more carefully considered. In this study, the thermal performances of 3 type CSPs named $\mu-BGA$^{TM}$$ $UltraCSP^{TM}$ and OmegaCSP$^{TM}$ were measured under the JEDEC specifications and their thermal characteristics were of a simulation model utilizing CFD and FEM code. The results show that there is a good agreement between the simulation and measurement within Max. 10% of $\circledM_{ja}$. And they show the wafer level CSPs have a superior thermal performance than that of $\mu-BGA.$ Especially the analysis results show that the thermal performance of wafer level CSPs are excellent fur modulo level in real operational mode without any heat sink.