• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.235-238
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• 2004

대부분의 보청기 이용자들은 자신이 장애를 겪고 있다는 사실이 알려지는 것을 꺼린다. 따라서 보청기 사용자들은 귀 바깥쪽으로 들어 나지 않는 귓속형(ITE type) 보청기를 선호한다. 하지만, 이러한 귓속형 보청기를 제작하는 것은 쉬운 일이 아니다. 보청기의 각각 부품들만을 볼 때는 그 크기가 소형이지만, 부품 모두를 귀속에 넣는다고 한다면, 공간의 확보는 꼭 필요한 사항이다. 또한 보청기는 하나의 칩(chip)에 부품이 전선(wire)을 통해 납땜이 되는 구조이다. 이는 전선의 단락을 유발할 뿐만 아니라 칩과 전선이 쉽게 떨어지며, 잦은 납Eoa 작업으로 인해 열적으로 칩의 파손까지도 일으킨다. 이를 보안하고자 여기에서는 보청기 소형화 방법으로 PCB(Printed Circuit Board)를 제시하였다. PCB 를 사용함으로써 전선의 사용을 최소화하고, 부품과 PCB 와의 직접적인 결합으로 인해 보다 견고한 보청기 제작을 목표로 하였다. 아울러 PCB 를 통한 부품의 실장으로 기존의 수작업이던 보청기 제작을 자동화와 제작 시간의 단축이라는 이점을 얻을 수 있다.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.10a
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• pp.43-46
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• 2006

본 논문은 PCB(printed circuit board)에 납땜이 되어 장착된 부품들의 들뜸 상태 검사 알고리즘에 관한 연구이다. 전자산업의 발달로 제품이 소형화, SMD화, 고집적화가 함께 추구되고 있으며, 특히 리드(lead)의 fine-pitch화 현상으로 인해 부품의 들뜸 상태 검사의 중요성은 매우 부각되고 있다. 따라서 본 논문에서는 2차원 포인터 레이저 거리센서를 이용하여 PCB위에 장착된 부품의 들뜸 상태를 검사하고자 한다. 이를 위해 레이저 측정용 장치를 제작하여 부품의 들뜸 검사 알고리즘의 유용성 및 들뜸의 상태 판단 여부를 확인하였다. 본 논문에서 사용한 기준 부품은 각칩 형태로 된 저항, 커패시터와 BGA 및 QFP이며 이 부품들을 이용하여 리드와 바디의 들뜸 상태를 검사하였다. 검사 기준으로 리드의 들뜸은 Scan Teaching 방식을 이용하였으며, 바디의 들뜸은 단차 Teaching 방식을 이용하였다.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.109-112
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• 1996

The more integrated and smaller SMD are needed, new solder joints packaging technologies are developed in these days such as BGA(Ball Grid Array), Flip Chip, J-lead etc. But, it's unable to inspect solder joints in those devices by visual inspection methods, because they are hided by it's packages. To inspect those new SMD packages, an X-ray system for acquiring a cross-sectional image of a arbitrary plane is necessary. In this paper, an analysis for designing X-ray cross sectional imaging system is presented including the way for correcting the distortion of image intensifier. And we show computer simulation of that system with a simple PCB model to show it's usefulness in applying PCB solder joint inspection.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.264-267
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• 1996

This paper is aimed to develop a very reliable method for automatic inspection of the solder joints on PCBS. There have been lots of previous works using vision technologies, but they can not be used for inspecting BGA, FCA or other newly used devices. Thus we adopt X-ray technologies for solder joint inspection. We put our attention on reconstructing the 3D shapes of solder joints since it gives us the most detailed information on quality of solder joints. Laminography principle is used to reject the interferences from neighboring parts or leads. To verify the effectiveness of laminography, a simulation study is performed in the case of a solder joints on double sided PCB using.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.117-120
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• 1996

In this paper, a new approach to acquire the cross-sentional image for automatic solder joint inspection of double-sided PCB using X-ray source is presented. We designed the apparatus with fixed X-ray source to realize the cross-sectional image by tunning object and detector synchronously. The cross-sectional images are captured at several view angle of X-ray source, the geometric image distortions caused by view angle and the shape of image intensifier are compensated. The precision variation of cross-sectional image by the change of view angle was investigated. Also we acquired the cross-sectional image to the solder joint of double-sided PCB and reconstructed the shape of solder joint.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.8
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• pp.995-1000
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• 1999

This paper presents a optic system and a visual inspection algorithm looking for solder joint defects of J-lead chip which are more integrate and smaller than ones with Gull-wing on PCBs(Printed Circuit Boards). The visual inspection system is composed of three sections : host PC, imaging and driving parts. The host PC part controls the inspection devices and executes the inspection algorithm. The imaging part acquires and processes image data. And the driving part controls XY-table for automatic inspection. In this paper, the most important five features are extracted from input images to categorize four classes of solder joint defects in the case of J-lead chip and utilized to a back-propagation network for classification. Consequently, good accuracy of classification performance and effectiveness of chosen five features are examined by experiment using proposed inspection algorithm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.300-300
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• 2010

Ceramic capacitor의 에너지내량을 향상시켜 제품의 신뢰성을 높이고자 RF Sputtering을 이용하여 외부전극을 형성하였다. 본 연구에서는 Target의 종류, 증착 시간 및 열처리 유/무에 따른 Ceramic capacitor의 전기적 특성 및 미세구조를 분석하여 최적조건을 확립하였으며, 최적 증착 조건으로 제작한 Ceramic capacitor의 에너지내량을 측정하였다. Target은 Ni target과 Cu target을 사용하였으며, Sputtering 시간은 10, 30, 60분으로 하였다. Sputtering 시간에 따른 Ceramic capacitor의 용량 특성과 손실은 큰 차이가 없었지만, Wire 연결시 Sputtering 시간에 따라 납땜성의 차이가 나타났으며, 증착 시간과 열처리 유/무에 따른 에너지내량의 변화를 확인하였다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.2
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• pp.382-392
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• 1990

This study investigates the behavior of fatigue crack propagating between holes of holes filled with another materials. When holes of the holes filled with another materials are located symmetrically near a center crack, it is noted that the crack propagation rate is influenced by both the bonding force of the brazing part and the elastic modulus of another material. It is experimentally and analytically confirmed that the center crack stops when its tip reaches near the center line of the holes and a small crack is initiated from the boundaries of holes of the holes filled with another materials and it propagates to final fracture.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.5
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• pp.9-18
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• 1998

The components with J-lead. which are more integrated and smaller than ones with Gull-wing. are rapidly being used in electronic board such as the PCB, for they have the advantage of occupying a small space compared to the other components. However, the development of inspection system for these new components is not so rapid as component development. Component-inspection with J-lead using vision system is difficult because they are hidden from camera optical axis. X-ray inspection, which has the advantage of inspecting the inside of solder state, is used to J-lead inspection. However. it is high cost and dangerous by leaking out X-ray compared to vision system. Therefore, in this paper, we design vision system suited to J-lead inspection and then propose algorithm which have flexibility in mount and rand error.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.119-124
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• 1999

This paper presents new approach to technology pattern recognition of camera back cover and test of soldering. In real-time implementing of pattern recognition camera back cover and test of soldering, the MVB-03 vision board has been used. Image can be captured from standard CCD monochrome camera in resolutions up to 640$\times$480 pixels. Various options re available for color cameras, a synchronous camera reset, and linescan cameras. Image processing os performed using Texas Instruments TMS320C31 digital signal processors. Image display is via a standard composite video monitor and supports non-destructive color overlay. System processing is possible using c30 machine code. Application software can be written in Borland C++ or Visual C++