• 한국정밀공학회지
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• 제32권7호
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• pp.627-631
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• 2015

Conventional etching technology is in the face of problems such as dishing, erosion resulting from non-uniform removal of film. Advanced printed circuit board (PCB) requires accurate wire formation with the aid of planarization by chemical mechanical polishing (CMP). Linear roll CMP is a line contact continuous process which removes the film by pressurization and rotation while slurry is supplied to polishing pad attached to the roll. This paper focuses on the design of floating nozzle on the linear roll CMP equipment which makes the slurry supply uniformly on the roll pad. Experimental results show that removal rate using the floating nozzle increases 3 times higher than that without it and non-uniformity is less than 15%.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1449-1451
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• 1997

Busbar made with Cu or Cu alloys and producted by Plastic manufacturing process. In this study, we research the manufacturing trend of Cu clad Al busbar for low cost and light weight which used for a electric power supply of distributing board. The objectives of this study is the manufacturing of composite busbar on electric power supply, the process and application for Cu clad Al busbar and the relation between electric properties and manufacturing operating process on contact parties.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제4권3호
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• pp.316-321
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• 2004

In this paper, we have developed a new mounting head system for flip chip. The proposed head system consists of a macro/micro positioning actuator for stable force control. The macro actuator provides the system with a gross motion while the micro device yields fine tuned motion to reduce the harmful impact force that occurs between very small sized electronic parts and the surface of a PCB(printed circuit board). In order to show the effectiveness of the proposed macro/micro chip mounting system, we compared the proposed system with the conventional chip mounting head equipped with a macro actuator only. A series of experiments were executed under the mounting conditions such as various access velocities and PCB stiffness. As a result of this study, a satisfactory voice coil actuator as the micro actuator has been developed, and its performance meet well the specifications desired for the design of the chip mounting head system and show good correspondence between theoretical analysis and experimental results.

• 지구물리
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• 제6권2호
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• pp.79-87
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• 2003

An in-situ four-electrode contact resistivity probe system was designed, and field-tested in submarine sediments. Seismic survey was also performed to support and compare the results of electric survey. The probe was designed to be driven to selected depths below the seafloor using a Vibracore system. The four insulated electrodes were, spaced equidistant across the wedge, were extended beyond the probe tip to minimize effects of sediment disturbance by the wedge insertion. In-situ measurements of resistivity were recorded on board by precision electronic equipment consisting of signal generators and processors, and by temperature- monitoring systems. Overall limits of uncertainty at respective depths below the seafloor are up to ±10% of the measured values. Best estimates of conductivity are considered to be ±3 percent of the reported values. Resistivity measurements were made at six sites in carbonate sediments to a maximum depth of penetration of about 5 m. Average values of conductivity range between 0.88 and 1.21 mho/m. The results show the seabed is composed of alternating layers of relatively high-conductivity material (0.8 to 1.4 mho/m) in thicknesses of more or less one meter and layers about 30 cm thick having relatively low conductivities (0.4 to 0.8 mho/m).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.524-527
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• 2000

In this paper, we have studied minimization of the burr which occurred after $\mu$-BGA(ball grid array) singulation process, singulation of the multilayer with a pulsed Nd:YAG(266, 532 nm) laser is used to cut the metal layer which doesn't well absorb laser beam. Especially, the photoresist and $N_2$blowing is effective to minimize of the surface demage and burr. In this experiment, the $N_2$ blowing reduces a laser energy loss by debris and suppress a surface oxidation. The SEM(scanning electron microscopes) and non-contact 3D inspector are used to measure cutting line-width and surface demage. The $\mu$-BGA singulation threshold energy is 75.0 J/cm$^2$at 30 ${\mu}{\textrm}{m}$/s scan speed.

• 동력기계공학회지
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• 제17권4호
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• pp.139-146
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• 2013

Because the magnetic bearing supports levitating body without contact, wear, noise and vibration, it is very useful to high revolution machinery. In this paper we selected ATmega 128, a less expensive and widely used micro controller, for control the magnetic bearing system. And we selected the sampling time and the control gain of PID controller through trial-and-error. The control program of the one board controller utilized lookup table to reduce calculation time, and bit shifting for the integer calculation in instead of floating point calculation. As the results, the controller carried out relatively high speed PID control on sampling time 0.25 ms. At last the rotation test for the magnetic bearing system was carried out by 3 phase induction motor and air turbine.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.503-507
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• 2004

This paper is concerned with the measurement of low-frequency vibrations of structures using the image processing method. To measure the vibrations visually, the measurement system consists of a camera, an image grabber board, and a computer. The specific target installed on the structure is used to calculate the vibration of structure. The captured image is then converted into a pixel-based data and then analyzed numerically. The limitation of the system depends on the image capturing speed and the size of image. In this paper, we discuss the methodology for the vibration measurement using the image processing method. The method enables us to measure the displacement directly without any contact. The resolution of the vibration measurement can be refined but limited to the sub centimeter displacement.

• 대한기계학회논문집A
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• 제36권3호
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• pp.347-353
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• 2012

최근 휴대폰은 스마트폰의 출연으로 다기능화가 요구되고 있으며, 각 보드의 전기적 신호를 연결시키는 커넥터는 필수 핵심 부품이 되었다. 커넥터는 많은 양의 전기신호를 처리하기 때문에 소형화, 협피치화가 필요하다. 하지만, 커넥터의 소형화 및 협피치화는 구조적 안전성을 저하시키며, 외부하중에 의한 접촉불량을 발생시킨다. 따라서 본 논문에서는 초소형 협피치 FPC 커넥터를 개발하기 위해 벤치마킹을 통한 초기설계안을 도출하였으며, 터미널 두께 0.2mm, 개수 50 개를 기준으로 하였다. 체결성능을 평가하기 위해 수치해석 모델을 구성하였으며, 다구찌 방법을 이용하여 형상 최적화를 수행하였다. 또한, 터미널의 한계수명을 예측하기 위해 피로해석을 수행하였으며, 체결 성능이 향상된 최종형상을 도출하였다.

• 한국의상디자인학회지
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• 제9권2호
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• pp.155-166
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• 2007

The purpose of the research is to provide the operation plans of internet marketing for effective application as marketing tools by analyzing the application status of marketing mix through the 30 websites of sportswear brands. Firstly, a study on the marketing mix strategy of sportswear brands presents that most brands put a high priority on promotion strategy by achieving online marketing. Secondly, compared with the other company brands which have online shopping mall, the website of sportswear brands consists of centered brand image. Therefore, based on the analysis about the variety of products and merchandise picture in each item and detailed information offer of neo-products introduction, marketing mix is insufficient in the website of sportswear and the price strategy has the least information. After website of sportswear brands is connected with online-shopping mall, guidance for its price and product is performed mainly. Consequently the sales promotion strategy of price needs development through the incentive and discount price. Promotion strategy occupies more parts than any other strategy. Especially, it allows a high proportion of the variety of events and information for the customer services. Also it needs to improve its bulletin board and Q&A board on the website for better communication with customers. Furthermore distribution strategy focuses on information such as location, contact numbers and address of the online shopping mall. Although online shopping mall has its own advantage which is marketing on the internet, it is not yet in progress.

• 마이크로전자및패키징학회지
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• 제22권1호
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• pp.35-41
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• 2015

In this study, in order to improve the reliability of ACF interconnections, solder ACF joints were investigated interms of solder joint morphology and solder wetting areas, and evaluated the electrical properties of Flex-on-Board (FOB) interconncections. Solder ACF joints with the ultrasonic bonding method showed excellent solder wetting by broken solder oxide layers on solder surfaces compared with solder joints with remaining solder oxide layer bonded by the conventional thermo-compression (TC) bonding method. When higher target temperature was used, Sn58Bi solder joints showed concave shape due to lower degree of cure of resin at solder MP by higher heating rate. ACFs with epoxy resins and SAC305 solders showed lower degree of resin cure at solder MP due to the slow curing rate resulting in concave shaped solder joints. In terms of solder wetting area, solder ACFs with $25-32{\mu}m$ diameters and 30-40 wt% showed highest wetted solder areas. Solder ACF joints with the concave shape and the highest wetting area showed lower contact resistances and higher reliability in PCT results than conventional ACF joints. These results indicate that solder morphologies and wetting areas of solder ACF joints can be controlled by adjustment of bonding conditions and material properties of solder and polymer resin to improve reliability of ACF joints.