• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.2
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• pp.253-266
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• 1998

A numerical study on the cooling performance for electronic components mounted with heat sink in an electronic system has been performed. The model of electronic system consisted with lower and upper modules in which the electronic components mounted with heat sink were arrayed. To find better configuration under a given fan power for effective cooling, the cases called 'No heat sink','Both heat sinks','Lower heat sinks', and 'Upper heat sinks' were tested. The results showed that the cooling performance in 'Upper heat sinks' was the best among four cases.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.8
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• pp.120-128
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• 2004

The impulse between launch vehicle and atmosphere can generate a lot of noise and vibration during the process of launching a satellite. Structurally, the electronic equipment of a satellite consists of an aluminum case containing PCB. Each PCB has resistors and IC. Noise and vibration of the wide frequency band are transferred to the inside of fairing, subsequently creating vibration of the electronic equipment of the satellite. In this situation, random vibration can cause malfunctioning of the electronic equipment of the device. Furthermore, when the frequency of random vibration meets with natural frequency of PCB, fatigue fracture may occur in the part of solder joint. The launching environment, thus, needs to be carefully considered when designing the electronic equipment of a satellite. In general, the safety of the electronic equipment is supposed to be related to the natural frequency, shapes of mode and dynamic deflection of PCB in the electronic equipment. Structural vibration analysis of PCB and its electronic components can be performed using either FEM or vibration test. In this study, the natural frequency and dynamic deflection of PCB are measured by FEM, and the safety of the electronic components of PCB is evaluated according to the results. This study presents a unique method for finite element modeling and analysis of PCB and its electronic components. The results of FEA are verified by vibration test. The method proposed herein may be applicable to various designs ranging from the electronic equipments of a satellite to home electronics.

• Journal of the Korean Society of Tobacco Science
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• v.22 no.2
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• pp.170-175
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• 2000

This study was carried out to compare the quality of licorices from various cultivating areas. licorice samples used in this study were collected from North-east and Sinkiang area in China, Mongolia, Uzvekistan and Kazahstan. The chemical components of licorice samples were analyzed and the signal patterns of the electracts were detected by the electronic nose. Contents of glycyrrhizin and glicyrrhizic acid, the key components of licorice were distributed in the region of 16.7～25.2% and 5.8～10.2%, respectively and were various according to the samples of the collected areas. In glycyrrhizin contents, root of Sinkiang showed the lowest value of 16.7%, and that of North-east the highest of 25.2%. In glycyrrhizic acid contents, root of Sinkiang showed the lowest of 5.8 %, and Kazahstan showed the highest of 10.2 %. Composition ratio of glycyrrhizin to glycyrrhizic acid was not always limear. As other components is other components affecting quality, contents of ash, starch and gums were 2.4～3.7%, 0.2～3.9%, respectively. When the headspace volatiles of licorices were analyzed using Electronic Nose System and the obtained data were interpreted using statistical method of MANOVA, characteristic patterns of licorices were different from each other according to collected area and its p value showed 0.0001. These results suggest that licorices may be discriminated from the collected areas by using Electronic Nose System.

• Proceedings of the Korean Society for Quality Management Conference
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• 1998.11a
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• pp.287-292
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• 1998

As business looks towards the $21^{\st}$ century, a long-term strategy that focuses on global sourcing will be the vital factor in whether companies win or lose. At the same time, with electronic components, it is important to ensure stable quality and reliability, together with other important parameters. In order to achieve this, creating an effective mechanism of failure analysis and database management for electronic components is essential. The authors introduce the actual mechanism employed by NEC and explain the ideas and insight they have obtained from their experience.

• Transactions on Electrical and Electronic Materials
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• v.11 no.3
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• pp.106-111
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• 2010

The convergence of significantly different and disparate technologies such as spintronics, carbon nano tube field effect transistors, photon and bio-responsive molecular switches, memristor and memristive systems and metamaterials, coupled with energy scavenging sources are gaining a renewed focus in the quest for new products. This paper will provide an insight into an anticipated technological revolution and will highlight a futuristic Roadmap to capture opportunities that are brought about as the results of formulation of new circuit components basically driven by emergence of nanoscale materials as part of System on System integration. Challenges as the result of new lumped components such as memristor, metamaterial-based lumped components and the like that will challenge the designers' comfort zone will also be discussed.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.6
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• pp.854-861
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• 2008

Heat transfer characteristics of protruding electronic components in a horizontal channel are studied numerically. The system consists of two horizontal channels formed by two covers and one printed circuit board which has three uniform protruding heat source blocks. A two-dimensional numerical model has been developed to predict the conjugate heat transfer. and the finite volume method is used to solve the problem. Five different cooling methods are considered to examine the heat transfer characteristics of electronic components according to the different cooling methods. The velocity and temperature of cooling medium and the temperature of the heat source blocks are obtained. The results of the five different cooling methods are compared to find out the most efficient cooling method in a given geometry and heat sources.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.1
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• pp.1-9
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• 2002

The thermal response of electronic components during infrared reflow soldering is studied by a two-dimensional numerical model. The convective, radiative and conduction heat transfer within the reflow oven as well as within the card assembly are simulated. Parametric study is also performed to determine the thermal response of electronic components to various conditions such as conveyor velocities, exhaust velocities and emissivities. The results of this study can be used in selecting the oven operating conditions to ensure proper solder melting and minimization of thermally induced card assembly stresses.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.2
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• pp.1-10
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• 2016

This paper reports the trends of researches and technologies of electronic packaging using graphene. Electronic packaging is to provide the signal and electrical current among electronic components, to remove the heat in electronic systems or components, to protect and support the electronic components from external environment. As the required functions and performances of electronic systems or components increase, the electronic packaging has been intensively attracted attention. Therefore, technologies such as miniaturization, high density, Pb-free material, high reliability, heat dissipation and so on, are required in electronic packaging. Recently, graphene, which is a single two-dimensional layer of carbon atoms, has been extensively investigated because of its superior mechanical, electrical and thermal properties. Until now, many studies have been reported the applications using graphene such as flexible display, electrode, super capacitor, composite materials and so on. In this paper, we will introduce and discuss various studies on recent technologies of electronic packaging using graphene for solving the required issues.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.503-504
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• 2006

This paper describes a low-level partial discharge(PD) testing that has been accepted as a non-destructive test method on insulation performance of electronic components. A comparative PD analysis combined with the Withstand Voltage Test (WVT) specified in IEC standards is carried out on high frequency switching transformers. The analysis shows that insulation degradation of the transformers under test progresses during the WVT. To avoid insulation degradation of the specimen, PD test has to be carried out at as low voltage as possible. In this study, the PD test on the transformers is performed in ranges from 50% to 70% of the test voltage specified in the WVT by measuring apparent charges below 1 pC. From the experimental results, it is expects that the low-level PD test is applicable for electronic components as a replacement of the WVT.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.6
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• pp.672-677
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• 1996

Volatile flavour components rates from aromatic rices were analyzed by Electronic nose systems. In functional group, polar compounds and aldehyde compounds showed much of volatile flavour components than apolar compounds, sulphur compounds and aminated compounds. The profiles of volatile flavour components rates were markedly differents of sen-sing times, amylose content.