• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.605-608
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• 1996

The aim of this thesis is to develop a SMT-components placement inspection system equipped with a visual sensor. The visual sensor, which consists of a camera and 2-layer LED illuminator, developed to inspect the component placement state such as missing, shift, flipping, polarity and tomb-stone. on PCB in the reflow-process. In practical applications, however, it is too hard to classify component from images mixed pad on PCB, cream solder paste and component. To overcome the problem, this thesis proposes the 2-layer illumination method and the heuristic image processing algorithms according to inspection type. To show the effectiveness of the proposed approach, a series of experiments on the inspection were conducted. The results show that the proposed method is robust to visual noise and variations in component conditions.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.11
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• pp.23-31
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• 2003

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.10
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• pp.982-987
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• 2015

The inspection machine in SMT (Surface Mount Technology) line detects the assembly defects such as missing, misalignment, loosing, or tombstone. We propose a new method to classify the defect types of chip components by processing the image of PCB. Two original images are obtained from horizontal lighting and vertical lighting. The image of the component is divided into two soldering regions and one packaging region. The features are extracted by appling the PCA (Principle Component Analysis) to each region. The MLP (Multilayer Perceptron) and SVM (Support Vector Machine) are then used to classify the defect types by learning. The experimental results are presented to show the usefulness of the proposed method.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.3
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• pp.135-140
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• 2017

SMT is an equipment that picks up electronic components and does precise placing onto PCBs. In order to do this, it stops in front of a camera installed in the middle to go over vision inspection. And after that it is move for placing. In this paper, We compared to the method of the placing after inspect to the stoped component and the moving component in front of the camera. As a result, This paper shows that the time efficiency of the fly-motion was increased by 9 percent than the stop-motion.

• Journal of Information Processing Systems
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• v.17 no.1
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• pp.203-212
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• 2021

To eliminate ambiguities in the existing methods to simplify Chinese pronunciation learning, we propose a model that can predict the pronunciation of Chinese characters automatically. The proposed model relies on a statistical machine translation (SMT) framework. In particular, we consider the components of Chinese characters as the basic unit and consider the pronunciation prediction as a machine translation procedure (the component sequence as a source sentence, the pronunciation, pinyin, as a target sentence). In addition to traditional features such as the bidirectional word translation and the n-gram language model, we also implement a component similarity feature to overcome some typos during practical use. We incorporate these features into a log-linear model. The experimental results show that our approach significantly outperforms other baseline models.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1758-1759
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• 2007

본 논문에서는 표면실장기판을 위한 자동 광학 검사 시스템에서 사용되는 데이터 산출방법에 대한 알고리즘을 제안 한다. 제안된 새로운 부품검사 알고리즘은 검사영역을 분할해 템플릿에서의 매칭률이 가장 높은 부분만을 세밀하게 재검사하는 방법을 사용하여 기존의 방법들보다 시간이 단축 될 뿐만 아니라 많은 양의 메모리를 필요로 하는 템플릿의 패턴들의 메모리 용량상의 문제점을 해결할 수 있다. 실험 결과를 제시하여 제안된 검사 알고리즘을 검증한다.

• Journal of Platform Technology
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• v.8 no.1
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• pp.24-32
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• 2020

This paper designed and manufactured a chip mounter based on 3D printer technology that can be used for educational research or sample production to disseminate chip mounter, a core technology of SMT line. A stepper motor with open loop control is used for low cost drive design. The shortcomings of the motor's vibration and disassembly caused by the use of the step motor were compensated by the Micro-Step control method. In the chip mounter experiment, the gerber file was generated on the small chip mounter, printed at the actual size, and the solder cream was printed on the HASL-treated PCB in the same manner as the sample board fabrication. As a result of the experiment, unlike the 2012 micro components, parts such as SOIC and TQFP that require correction are twice as long as the component mounting time, but it can be confirmed that they are mounted relatively accurately. In addition, as a result of repeatedly measuring the error of the initial position 10 times, it was confirmed that a relatively small error of about 0.110mm occurs.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.3
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• pp.31-35
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• 2022

Recently, with the 4th industrial revolution, the demand for high-density semiconductors for large-capacity data processing is increasing. Researchers are interested in researching the reliability of surface mount technology (SMT). In this study, the effect of PCB pad design on assembly and adhesion reliability of passive component was analyzed using design of experiment (DOE). The DOE method was established using the pad length, width, and distance between pads of the PCB as variables. The assembly defect rate of the passive element after the reflow process was derived according to the misplacement direction of the chip resistor. The shear force between the passive element and the PCB was measured using shear tests. In addition, the shape of the solder according to the pad design was analyzed through cross-sectional analysis.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.167-171
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• 2001

In PCB assembling line, it needs SMD mounter. In this paper, the feeder of the SMD mounter, which carry component to the mounter is designed. Up to now, mechanical air feeder is mainly used. But in these days, it is developed to the electrical feeder with network. There are many kind of feeders with various control technique. In this paper, the feeder with BLDC motor and LON chip is designed and implemented. Then the experimental results are presented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6863-6869
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• 2014

A SMT machine is used to place electronic components on a PCB precisely. To place it precisely, after a component inspection, it finds an offset value using a vision camera, and places the precise position on the PCB. In general, to inspect the components with a vision camera, the components stop in front of the camera for inspection, then move to the placement position. On the other hand, if they do not stop in front of a camera, the inspection time will be shortened and the productivity would be increased. In this thesis, when inspecting without stopping in front of a camera, the fastest way among various routes is described. For the gantry passing over a vision camera, both the distance and speed of a gantry moving trajectory were studied, and there was approximately 5% speed increment when using the method suggested in this thesis.