• Journal of Sensor Science and Technology
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• v.27 no.5
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• pp.340-344
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• 2018

Electrodes are an important part of electrocardiography (ECG); disposable electrodes have been extensively used. However, personal ECG monitoring devices for Internet of Things applications require reusable electrodes. As there have been no systematic studies on the characteristics of reusable electrodes to date, we conducted this study to assess the performance and feasibility of electrodes with different materials. We built reusable electrodes using twelve different metallic materials, including commonly used copper, silver, zinc, plating materials, chemically inert titanium, stainless steel, and aluminum. Each electrode was fabricated to a size of $5{\times}10mm$. Their characteristics such as offset, baseline drift, stabilization time, and chemical inertness were compared. A personal ECG monitoring system was used to test the manufactured electrodes. The performances of the Ag, Cu, and Zn electrodes were better than the performances of other electrodes. However, these materials may not be used owing to the chemical changes that occur when the electrodes are in contact with the skin, such as discoloration and corrosion, which deteriorate their electrical characteristics. Titanium, stainless steel, and aluminum are chemically stable. The titanium electrode showed the best performance among the three, and it is our recommendation as a material for manufacturing reusable electrodes.

• Journal of the Korean Vacuum Society
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• v.8 no.4A
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• pp.482-489
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• 1999

AC PDP(P1asma Display Pane1)s use the mixture of inert gases to generate a discharge inside the display pixels. Impurities such as CO, $CO_2$ and OH inside discharge region may deteriorate the characteristics of PDP operation during long life time of PDP. Electro-negative gas such as CO can cause the sustain pulse amplitude to rise by attaching electrons which will play an important role in the earlier stage of the discharge. MgO film is used to protect the dielectric layer in AC PDP, and is in contact with the free space of display pixel where it is filled with the inert gas mixture. So, MgO film can be a main source of impurities. In this experiment, we observed the change of impurity generation of various MgO films which were deposited by different methods, by using QMS. (quadropole mass spectrometer) The main impurites were $H_2$, CO and $CO_2$. And with the comparison of the TPD (temperature programmed desorption) result, it can be understood that impurity gases are generated by sputtering of MgO surface not by outgassing. Deposition method had effects on the characteristics of the impurity generation. The MgO film manufactured by e-beam evaporation generated more amount of impurity gases than the MgO films manufactured by sputtering or ion-plating. And also heat treatment of MgO film after deposition decreased the magnitude of impurity gas generation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.12-12
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• 2008

Ruthenium is one of the noble metals having good thermal and chemical stability, low resistivity, and relatively high work function(4.71eV). Because of these good physical, chemical, and electrical properties, Ru thin films have been extensively studied for various applications in semiconductor devices such as gate electrode for FET, capacitor electrodes for dynamic random access memories(DRAMs) with high-k dielectrics such as $Ta_2O_5$ and (Ba,Sr)$TiO_3$, and capacitor electrode for ferroelectric random access memories(FRAMs) with Pb(Zr,Ti)$O_3$. Additionally, Ru thin films have been studied for copper(Cu) seed layers for Cu electrochemical plating(ECP) in metallization process because of its good adhesion to and immiscibility with Cu. We investigated Ru thin films by thermal ALD with various deposition parameters such as deposition temperature, oxygen flow rate, and source pulse time. Ru thin films were grown by ALD(Lucida D100, NCD Co.) using RuDi as precursor and $O_2$ gas as a reactant at 200~$350^{\circ}C$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.257-262
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• 2008

In this paper, the key parameters of $CO_2$ laser(focus depth, air blow rate, total laser beam time, number of pulse) are experimented for thru-hole and scribing line on AIN(aluminum nitride) substrate with high thermal conductivity. And, microstrip line & spiral planar inductor are fabricated on AIN substrate using 5 um Cu-plating with self-masking technique. The microstrip line of AIN has 0.1 dB/mm attenuation at 10 GHz and 6 nH spiral planar inductor has 56 maximum quality factor at 1 GHz. Thus, the AIN substrate is promising for GHz applications of high power area.

• Structural Engineering and Mechanics
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• v.9 no.5
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• pp.505-518
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• 2000

A major cause of premature debonding of tension face plates is shear peeling (Jones et al. 1988, Swamy et al. 1989, Ziraba et al. 1994, Zhang et al. 1995), that is debonding at the plate ends that is associated with the formation of shear diagonal cracks that are caused by the action of vertical shear forces. It is shown in this paper how side plated beams are less prone to shear peeling than tension face plated beams, as the side plate automatically increases the resistance of the reinforced concrete beam to shear peeling. Tests are used to determine the increase in the shear peeling resistance that the side plates provide, and also the effect of vertical shear forces on the pure flexural peeling strength that was determined in the companion paper. Design rules are then developed to prevent premature debonding of the plate ends due to peeling and they are applied to the strengthening and stiffening of continuous reinforced concrete beams. It is shown how these design rules for side plated beams can be adapted to allow for propped and unpropped construction and the time effects of creep and shrinkage, and how side plates can be used in conjunction with tension face plates.

• Journal of the Microelectronics and Packaging Society
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• v.14 no.3
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• pp.37-42
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• 2007

Copper deposition studies have been actively studied since interests on 3D SiP were increased. The defects inside via can be easily formed due to the current density differences on entrance, bottom and wall of via. So far many different additives and current types were discussed and optimized to obtain void-free copper via filling. In this research acid cupric sulfate plating bath containing additives such as PEG, SPS, JGB, PEI and wave current applied electroplating were examined. The size and shape of grain were influenced by the types of organic additives. The cross section of specimen were analyzed by FESEM. When PEI was added, the denser copper deposits were obtained. Electroplaing time was reduced when 2 step via filling was employed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.9
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• pp.835-840
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• 2004

Using of small Radar device can not supply the real exercise information of ellipse circumference or CPA, TCPA and the changing of surroundings fur various target information. Therefore, for the above problem, we develop RTE that is able to and of for each information from ARPA Radar which supply analog video signal, trigger bearing and heading pulse from low-cost small Radar device is equiped with general small fishing boat. The small fishing is equipped with small Radar device, so it is able to collect and apply sailing information such as real exercise information and TCPA.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.121-121
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• 2000

반도체 산업의 발달에 따라 소자의 보다 빠른 동작 속도와 큰 집적도를 갖은 ULSI 구조를 얻기 위해, 새로운 금속배선 재료가 요구되고 있다. 기존의 금속 배선인 Al 및 Al 합금은 비교적 낮은 비저항과 박막형성의 용이함으로 인하여 현재까지 금속배선 재료로 사용되고 있으나, 고집적화에 따라 RC Time Delay와 Electromigration의 문제점을 들어내었다. 이러한 문제를 해결할 새로운 배선 재료로 Al보다 낮은 비저항을 가지며, electromigration 저항성을 갖는 Cu 금속배선 재료가 활발히 연구되고 있다. 본 실험에서는 (100) Si 웨이퍼를 기판으로 사용하였으며, 각층은 SiO2/Si3N4/EP Cu/Seed Cu/ TaN/SiO2/Si wafer 상태로 증착하였다. 확산방지막으로 TaN을 사용하였고, seed Cu는 sputtering 으로 증착하였으며, seed Cu 만으로 된 박막과 seed Cu + electro plating Cu로 구성된 박막을 제작하였다. 제작 완료된 박막은 N2 분위기에서 20$0^{\circ}C$ 120 min, 45$0^{\circ}C$ 60min 동안 열처리하여 Cu 박막의 조직 변화를 TEM 및 여러 분석방법을 이용하여 분석하였다. Plan-view TEM결과, 45$0^{\circ}C$, 60min 열처리함에 따라 결정립 성장이 일어난 것을 확인 할 수 있었다. 그러나, 성장후에도 twin boundary, stacking fault, dislocation, small defect 등은 여전히 남아 있음이 관찰된다. 그림 1(a)는 as-deposit 상태이며, 그림 1(b)는 45$0^{\circ}C$, 60min 열처리한 plan-view TEM 사진이다.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.4
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• pp.51-56
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• 2003

Generally, the build-up printed circuit board manufactured by a sequential process involving etching, plating, drilling, etc, which requires many types of equipments and long lead time. Etching process is suitable for mass production, however, it is not adequate for manufacturing a prototype in the development stage. In this study, we introduce a screen printing technology for prototyping a build-up printed circuit board. As for the material, photo/thermal curable resin and conductive paste are used for the formation of dielectric and conductor. The build-up structure is made by subsequent processes such as formation of a liquid resin thin layer, solidification by a UV/IR light, and via hole filling with a conductive paste. By use of photo curable resin, productivity is greatly enhanced compared with thermal curable resin. Finally, the basic concept and the possibility of build-up printed circuit board prototyping are proposed in comparison with the conventional process.

• Journal of Microbiology
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• v.39 no.4
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• pp.321-325
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• 2001

Baird-Parker agar with egg yolk/tellurite emulsion (BPA) is widely accepted as a medium for the enu-meration of Staphylococcus aureus in foods. Howerver, it is not vompletely selective and colonies of other genera of species could be similar to those of Staphylococcus aureus. Moreover, the strains of Staphylococcus aureus that are lecithinase negatrive could go unnoticed. Both facts could affect the counts. The aim of this study was to dtermine whether the enumeration of the colonies with the typical morphol-ogy of Staphylococcus aureus on BPA is sufficien to quantity this species in poultry meat. Forty chiken carcasses were tested for Staphylococcus aureus by surface plating using BPA, Results indicate that the predictiv value of the morphoogy of the colonies of BPA is 85.71% and 68.42% for typical and atypical colonies of Staphylococcus aureus, respectively. However, Staphylococcus aureus counts (after identification) and counts of typical colonies did not show any significant differences(P>0.05) and are significantly(P<0.001) correlated (r=0.996).These results suggest that , for screening purposes. enumeration of Staphylococcus aureus from poultry meat does not require any identification of stains. resulting in a saving of time and money.