• Journal of Applied Reliability
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• v.5 no.2
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• pp.221-239
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• 2005

General chip SMD parts(chip resistance, chip capacitor, chip varistor etc.) are very wide used electronics parts for IT units. But, failure modes are indistinct for these chip parts. In factory and field the failure modes are recognized to accidental failure mode caused by potential defect. In this paper used chip varistor ALT(Accelerate Life Test) test for verify general failure modes in chip SMD parts. Also the results are useful for general chip SMD ALT tests.

• Proceedings of the Korean Reliability Society Conference
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• 2005.06a
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• pp.51-67
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• 2005

General chip SMD parts(chip resistance, chip capacitor, chip varistor etc.) are very wide sed electronics parts for IT units. But, failure modes are indistinct for these chip parts. In factory and field the failure modes are recognized to accidental failure mope caused by potential defect. In this paper used chip varistor ALT(Accelerate Life Test) test for verify general failure modes in chip SMD parts. Also the results are useful for general chip SMD ALT tests.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.11a
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• pp.131-135
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• 2002

In this project, we have developed various techniques for subminiaturization, surface implementation, high frequency design, small-sizes SMD, performance test and applications of ultra small chip antenna, which is a core component for the personal communication systems. We also obtained base techniques for the next-generation ultra small chip antenna design and fabrication techniques for an internationally competitive subminiature ultra small chip antenna. Center frequency is 2442.5MHz(Type), return loss is -10dB max, VSWR is 2max, xy max gain is -2dB min, size is 0.05ccmax.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1039-1042
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• 2002

SMD(Surface Mounting Device) which mounts electronic components as IC-Chips on PCB automatically, produces a large dynamic force and vibration. The unwanted vibrations in SMD degrade the performance of the precision device and it is the major obstacle to limit its speed for mounting. This study investigated the vibration analysis of a typical SMD to predict the natural frequencies and mode shapes. To validate the finite element analysis of SMD, the FE result was compared with that of ODS measurements. It was shown that the predicted results were well correlated with the experimental modal parameters.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.121-125
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• 2001

SMD mounter is necessary in PCB assembling line. To feed SMD components to the mounter, high performance feeders are needed. Until now, mechanical air feeders have been mainly used. However, in these days, electrical feeders with network are developed. There are many kinds of feeders with various control techniques. In this paper, a feeder with BLDC motor and LON chip is designed and implemented. And, the experimental results are presented.

• Journal of Korean Electronics
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• v.10 no.6
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• pp.26-31
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• 1990

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1133-1138
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• 2007

DLLs(Delay Locked Loops) have widely been used in many systems in order to achieve the clock synchronization. A SMD (Synchronous Mirror Delay) structure is used both for skew reduction and for DCC (Duty Cycle Correction). In this paper, a SMD based DLL with DCC using Reduced Delay Lines is proposed in order to reduce the clock skew and correct the duty cycle. The merged structure allows the forward delay array to be shared between the DLL and the DCC, and yields a 25% saving in the number of the required delay cells. The designed chip was fabricated using a $0.25{\mu}m$ 1-poly, 4-metal CMOS process. Measurement results showed the 3% duty cycle error when the input signal ranges from 80% to 20% and the clock frequency ranges from 400MHz to 600MHz. The locking operation needs 3 clock and duty correction requires only 5 clock cycles as feature with SMD structure.

• Proceedings of the KAIS Fall Conference
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• 2010.05a
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• pp.124-127
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• 2010

본 논문에서는 소형 SMD 솔레노이드 형태의 RF 칩 인덕터의 최적 구조를 도출하였다. $1.0\times0.5\times0.5mm^3$ 크기의 96% $Al_2O_3$ 코아는 $40{\mu}m$ 직경의 구리 코일을 4회 권선하여 8.57nH의 인덕턴스, 37.6의 품질계수와 6.05GHz의 SRF를 가진다. $40{\mu}m$ 직경의 구리 코일을 0.35mm 솔레노이드 길이로 중앙에 6회 권선하였을 경우가 250MHz11.2nH의 인덕턴스, 29.8의 품질계수와 5.6GHz의 SRF로 가장 우수하였다.

• 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 Institute of Control, Robotics and Systems
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• v.5 no.6
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• pp.698-704
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• 1999

There are several types of defects of SMDs mounted on PCB, that is, missing components, misalignment, wrong parts and poor solder joints. This research study mainly focuses on measuring of deviation of SMD leads using the partial image of component, not using the full image. This processing based on the partial image has the advantage of the reduction in calculation time compared to the full image. Since position of lead is calculated with respect of the reduction in calculation time compared to the full image. Since position of lead is calculated with respect to pad, the accuracy of the system is not dependent on percise positioning stage. The grabbed image of gray scale is converted into binary format using a cutomatic threshold. After small fragments in the image is removed by a series of morphology operations such as opening and closing, the centroids of PCB pads and SMD leads is obtained together with labeling of blobs. Translational shift and rotationial angle of SMD are succedingly estimated using above information and chip data. The expression that can calculate the maximum deviation of leads with respect to PCB pads has been derived, and inferior mounting of SMD is judged by a given criterion. Some experiments have been executed to verify this measuring scheme.