• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.4
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• pp.1210-1215
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• 2010

The probe card are test modules which are to classify the good semiconductor chips and thin film before the packaging process. In the rapid growth a technology of semiconductor, the number of pads per unit area is increasing and pad arrays are becoming irregular. Therefore, the technology of probe card needs narrow width and lots of probe tip. In this paper, the probe tip based on the MEMS(Micro Electro Mechanical System)technology was developed a new MEMS probe tip for vertical probe card applications. For the structural designs of probe tip were performed to mechanical characteristics and structural analysis using FEM(Finite Element Method). Also, the contact force of MEMS probe tip compared with FEM results and experimental results. Finally, the MEMS probe card was developed a fine pitch smaller than $50{\mu}m$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.672-678
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• 2017

In this paper, we studied a design method for a broadband quasi-Yagi antenna (QYA) for terrestrial digital television (DTV) reception. The proposed antenna is composed of a dipole driver, a rectangular patch type director close to the dipole, and a ground reflector printed on an FR4 substrate. A balun between a microstrip line and a coplanar strip (CPS) line is a rectangular patch inserted along the center of the CPS. The end of the balun is connected to the CPS line through a shorting pin. An antenna, as an design example for the proposed antenna, is designed for the operation in the frequency band of 470-806 MHz for terrestrial DTV, and the characteristics of the designed antenna are examined. The antenna has a good performance such as a frequency band of 430-842 MHz for a voltage standing wave ratio < 2, a gain > 3.7 dBi, and a front-to-back ratio > 7.4 dB.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.906-912
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• 2017

In this paper, we studied a design method for a broadband 3-element quasi-Yagi antenna (QYA) for indoor digital television (DTV) reception. The proposed QYA employs a novel balun between a microstrip (MS) line and a coplanar strip (CPS) line feeding the driver dipole. The proposed balun is constructed by connecting the end of MS line to CPS line through a shorting pin, and the CPS and ground reflector are connected through a circular ring-type conductor. An antenna, as an design example for the proposed antenna, is designed for the operation in the frequency band of 470-806 MHz for terrestrial DTV. The antenna fabricated on an FR4 substrate with a size of $270mm{\times}150mm$ showed a good performance such as a frequency band of 470-820 MHz for a voltage standing wave ratio < 2, a gain > 4.0 dBi, and a front-to-back ratio > 8.4 dB over the DTV frequency band.

• Design & Manufacturing
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• v.10 no.1
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• pp.36-40
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• 2016

Connectors transmit electric signals to different parts in compact mobile display products. As products that apply this have become lightweight and smaller in size, there are growing demands for smaller and more integrated connectors, which are internal parts of the products. As a measure to address these demands, there is the planar array connector that minimizes the part by arranging the single-direction BTB connectors to two directions. As connectors become smaller in size and more highly integrated, maintaining intensity to prevent defects during impact and maintaining adhesive force to smoothly transmit electric signals are growing in importance. Thus, in order to identify the impact of concave shaping on improving adhesive power in connector terminal pins as a method to increase the connecting power of planar array connector terminal pins, this study predicted and examined the concave shaping method, number of concave shapes, and the adhesive power according to the size of the concave shape through CAE. For concave shaping, the model that added concave shaping towards the lower part of the connector terminal pin and added spokes for the area pressed down by the concave shaping was 0.74 N, showing increased adhesive force compared to existing models. Furthermore, when applying two concave shaping, rather than just one, there was a tendency for adhesive force to increase. In the case of adhesive power trends according to the size of the concave shaping, adhesive power increased and the width of the concave shape decreased, and the biggest adhesive force trends were shown when the concave shaping depth was 0.01mm.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.11
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• pp.1-5
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• 2010

We developed a novel micro-electro mechanical systems (MEMS) test socket using silicon on insulator (SOI) substrate with the cantilever array structure. We designed the round shaped cantilevers with the maximum length of $350{\mu}m$, the maximum width of $200{\mu}m$ and the thickness of $10{\mu}m$ for $650{\mu}m$ pitch for 8 mm x 8 mm area and 121 balls square ball grid array (BGA) packages. The MEMS test socket was fabricated by MEMS technology using metal lift off process and deep reactive ion etching (DRIE) silicon etcher and so on. The MEMS test socket has a simple structure, low production cost, fine pitch, high pin count and rapid prototyping. We verified the performances of the MEMS test sockets such as deflection as a function of the applied force, path resistance between the cantilever and the metal pad and the contact resistance. Fabricated cantilever has 1.3 gf (gram force) at $90{\mu}m$ deflection. Total path resistance was less than $17{\Omega}$. The contact resistance was approximately from 0.7 to $0.75{\Omega}$ for all cantilevers. Therefore the test socket is suitable for BGA integrated circuit (IC) packages tests.

• Journal of Energy Engineering
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• v.17 no.4
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• pp.189-197
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• 2008

In this study, a system to measure continuously the fuel concentration in a steady flow rig on the basis of Rayleigh scattering is presented. The system can be employed to measure both the temporal and the spatial distribution. Also, it is possible to calibrate the system for the measurement of accurate absolute concentration. Firstly, the system was tested at a calibration chamber for the determination of scattering cross section from propane, butane, acetylene, Freon-12 and Genetron 143a. After this, the system was adapted to a steady flow rig to measure the temporal and spatial fuel concentration. The rig is composed of cylinder head, intake manifold, injector, and transparent cylinder which can simulate internal combustion engine. To cope with the interference of Mie scattering, which is main obstacle of the measuring concentration with Rayleigh scattering, a hardware filter was installed for reducing the number density of particles. Furthermore a software filter was developed, which is based on the rise time and the time constant of the photomultiplier-amplifier system. In addition, background noisy was reduced by adjusting the optical array and applying the pin hall and beam trap. The results show that LRS can provide useful information about concentration field and the software filter is very effective method to remove Mie interference.

• Journal of Veterinary Clinics
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• v.31 no.6
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• pp.523-526
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• 2014

Three dogs were admitted for repair of bone fracture. Case 1 (Maltese, 1.8 kg, intact female, 5-month-old) and case 2 (poodle, 3.0 kg, intact female, 6-month-old) had non-weight bearing lameness in the left pelvic limb, and case 3 (mixed, 3.3 kg, intact female, age unknown) had non-weight-bearing lameness in the left thoracic limb. On orthopedic examination, there was pain, crepitus, palpable instability and substantial soft tissue swelling on the affected side. No neurological deficits were identified. Radiographs revealed left proximal metaphyseal tibial and fibular fractures in cases 1 and 2, and left proximal metaphyseal radial and ulnar fractures in case 3. All cases had closed long-bone fractures with short juxta-articular fracture segments. Under fluoroscopic guidance, proper placement of the ring fixation elements was confirmed during surgery. Two or three rings were used to stabilize fractures with traditional circular external skeletal fixators (CESF). Postoperative radiographs showed acceptable alignment and apposition of the previously identified fracture. Time to radiographic union ranged from 5 to 14 weeks and there were no signs of implant failure or pin tract infection. Functional outcomes were excellent in all cases. CESF can be successfully used to reduce short juxta-articular fractures in which bone plates or external skeletal fixation cannot be applied.

• Microbiology and Biotechnology Letters
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• v.32 no.2
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• pp.110-116
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• 2004

The over-expression in E. coli of the pHLN1-SO(＋) and pHLN2-80(－) plasmids cloned an insecticidal crystal protein (ICP) gene (crylAal type) from Bacillus thuringiensis var. kurstaki HD 1 was investigated through in part, the deletion of -80 bp promoter and an alternative change of cloning vector system. Two recombinant plasmids were constructed in an attempt to analyze the over-expression of the ICP in relations to its gene structure possessing only -14 bp ［Shine-Dalgarno (SD) sequence of -80 bp promoter］. Also, anther two recombinant plasmids similarly cloned the icp gene in a different vector system. The amounts of ICP produced from the recombinants were measured by SDS-PAGE and confirmed by Western blot analysis. One clone, pHLRBS1-14 clone in which only the SD sequence in the inverted orientation icp gene appeared, was more evident than the pHLRBS2-14 clone in which only the -14 bp SD sequence of the right orientated icp gene was shown to exist. The pHLN2-80(－) clone produced more ICP proteins than the pHLRBS1-14 clone. In the two clones, pHLNUC1-80 right-oriented icp gene and the pHLNUC2-80 clone inverted-orientation icp gene in a new different vector, the pHLNUC2-80 produced more ICP proteins in E. coli system. These results indicate that the P/ac promoter, the inverted icp gene insertion and -80 bp promoter (-66 bp part of the icp gene promoters), were concerned with the expression of the icp gene in the recombinant plasmids. In addition, the expression mechanism might result from the disruption of the transcription-suppressing regions in the promoter regions.