• Transactions on Electrical and Electronic Materials
• /
• v.8 no.2
• /
• pp.73-78
• /
• 2007

The crystallization temperature in GeTe solid electrolyte films was improved by in situ-nitrogen doping by rf magnetron co-sputtering technique at room temperature. The crystallization temperature of $250\;^{\circ}C$ in electrolyte films without nitrogen doping increased by approximately $300\;^{\circ}C$, $350\;^{\circ}C$, and above $400\;^{\circ}C$ in films deposited with nitrogen/argon flow ratios of 10, 20, and 30 %, respectively. A PMC memory device with $Ge_{45}Te_{55}$ solid electrolytes deposited with nitrogen/argon flow ratios of 20 % shows reproducible memory switching characteristics based on resistive switching at threshold voltage of 1.2 V with high $R_{off}/R_{on}$ ratios. Nitrogen doping into the silver saturated GeTe electrolyte films improves the crystallization temperature of electrolyte films and does not appear to have a negative impact on the switching characteristics of PMC memory devices.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.20 no.8
• /
• pp.711-715
• /
• 2007

Properties of organic light-emitting diodes (OLEDs) with aluminum-doped zinc oxide (ZnO:Al) anodes showed different behaviors from OLEDs with indium tin oxide (ITO) anodes according to driving conditions. OLEDs with ITO anodes gave higher current density and luminance in lower voltage region and better EL and power efficiency under lower current density conditions, However, OLEDs with ZnO:Al anodes gave higher current density and luminance in higher voltage region over about 8V and better EL and power efficiency under higher current density over $200mA/cm^2$. These seemed to be due to the differences in conduction properties of semiconducting ZnO:Al and metallic ITO. OLEDs with ZnO:Al anodes showed nearly saturated efficiency under high current driving conditions compared with those of OLEDs with ITO anodes. This meant better charge balance in OLEDs with ZnO:Al anodes. These properties of OLEDs with ZnO:Al anodes are useful in making bright display devices with efficiency.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.28 no.1
• /
• pp.57-63
• /
• 2015

Recently, LED is widely used in the kinds of display devices or lighting. In this paper, we fabricated LED chamber light for naval vessels to replace to conventional chamber light using incandescent lamp. The LED package of chamber light was designed with luminous intensity of 5.5 cd, color temperature of $6,000{\pm}500K$, forward voltage of 3~3.2 V and input current of 60 mA. A LED module was composed of 36 LED packages and metal PCB. The VF and luminous intensity of LED package were getting down when temperature increased. The temperature of LED chamber light was measured by changing the number of LED package and applied current for one hour when an electric current flow. The heat transfer capability have been improved by using metal PCB. The power consumption of LED chamber light reduced by 86% compared to the conventional chamber light using incandescent lamp.

• Proceedings of the KIEE Conference
• /
• 1997.07d
• /
• pp.1352-1354
• /
• 1997

Transparent conductive thin films have found many application in many active and passive electronic and opto-electronic devices as like flat Panel display electrode and window heat mirror, etc. Low resistivity and high transmittance of this films can be obtained by controlling deposition parameters, which are oxygen partial Pressure, substrate temperature and dopant concentration. In this study, We prepared non-stoichiometric and Sb-doped thin films of tin dioxide by reactive DC magnetron sputtering technology. The lowest resistivity of about $3.0{\times}10^{-3}\;{\Omega}cm$ and 80% transmittance in the visible light region have heed obtained at optimal deposition condition.

• Journal of Welding and Joining
• /
• v.29 no.5
• /
• pp.95-98
• /
• 2011

Recently, there is a growing tendency that fine-pitch electronic devices are increased due to higher density and very large scale integration. Finer pitch printed circuit board(PCB) is to be decrease insulation resistance between circuit patterns and electrical components, which will induce to electrical short in electronic circuit by electrochemical migration when it exposes to long term in high temperature and high humidity. In this research, the effect of soldering flux acting as an electrical carrier between conductors on electrochemical migration was investigated. The PCB pad was coated with OSP finish. Sn3.0Ag0.5Cu solder paste was printed on the PCB circuit and then the coupon was treated by reflow process. Thereby, specimen for ion migration test was fabricated. Electrochemical migration test was conducted under the condition of DC 48 V, $85^{\circ}C$, and 85 % relative humidity. Their life time could be increased about 22% by means of removal of flux. The fundamentals and mechanism of electrochemical migration was discussed depending on the existence of flux residues after reflow process.

• The Journal of the Korea Contents Association
• /
• v.13 no.4
• /
• pp.399-406
• /
• 2013

Recently, studies about process mining for creating and analyzing business process models from log data have received much attention from BPM (Business Process Management) researchers. Process mining is a kind of method that extracts meaningful information and hidden rules from the event log of enterprise information systems such as ERP and BPM. In this paper, repair processes of electronic devices are analyzed using ProM which is a process mining tool. And based on the analysis of repair processes, the method for finding major failure patterns is proposed by multi-dimensional data analysis beyond simple statistics. By using the proposed method, the reliability of electronic device can be increased by providing the identified failure patterns to design team.

• Journal of Surface Science and Engineering
• /
• v.30 no.6
• /
• pp.406-411
• /
• 1997

Transparent conductive thin films have found many applications in active and passive electronic and opto-electronic devices such as flat panel display electrode, solar cell electrode and window heat mirror, etc. Low resistivity and high transmittance of these films can beotained by controlling deposition parameters which are oxygen partial pressure, substrate temperature and dopant concentration. In this study, non-stoichiometric and Sb-doped thin electrical properties of undoped films have been degraded with increase of substrate temperature and optical properties have been improved in Sb-doped films. The resistivity of $2.5\times10^{-3}\Omega\textrm{cm}$,/TEX>, average transmittance of 80% and sheet resistance of 130$\Omega$/$\square$ at thickess of 2000 $\AA$ could be obrained at optmal condimal conditions which were at $400^{\circ}C$ of substrate temperature, 58% of oxygen partial pressure and 5% of Sb doping concentration.

• Journal of Institute of Control, Robotics and Systems
• /
• v.22 no.1
• /
• pp.59-65
• /
• 2016

As modern electronic devices get smaller and smaller, high-resolution, large Field-Of-View (FOV), fast, and cost-effective 3-dimensional (3-D) measurement is requested more and more. In particular, defect inspection machines using machine-vision technology nowadays require 3-D inspection as well as the conventional 2-D inspection. Phase Measuring Profilometry (PMP) is one of the fast non-contact 3-D shape measuring methods currently being extensively investigated in the electronic component manufacturing industry. The PMP system is well known and is successfully applied to measuring complex surface profiles with varying reflectance properties. However, for highly reflective surfaces, such as Ball Grid Arrays (BGAs), it has difficulty accurately measuring 3-D shapes. In this paper, we propose a new fast optical system that can eliminate the highly reflective saturated regions in BGA ball images. This is achieved by utilizing four Low Intensity Grating (LIG) images together with the conventional High Intensity Grating (HIG) images. Extensive experiments using BGA samples show a repeatability of under ${\pm}20um$ in standard deviation, which is suitable for most 3-D shape measurements of BGAs.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.15 no.2
• /
• pp.307-312
• /
• 2020

This paper proposed intelligent motor control system that replaced smart motor devices, such as motor protection relays, smart circuit breakers and variable speed drives, with one integrated module to perform efficient motor control at industrial sites. The proposed intelligent motor control system provides easy monitoring of critical data for each motor or load connected to an intelligent motor control system over a CIP(Common Industrial Protocol)-based network, which enables accurate process control at all times, real-time access to fault information and records to simplify diagnosis and minimize equipment downtime.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.15 no.1
• /
• pp.1-8
• /
• 2009

Purpose: The purposes of this study were to establish the concurrent validity of the universal goniometer and electronic inclinometer for ankle joint of motion, and to determine the inter-tester and the intra-tester reliability of these two instruments. Methods: Subjects were instructed 25 healthy subjects. Ankle range of motion was measured on two separate occasions 2 or 3 days by two physical therapists. Ankle dorsiflexion and plantarflexion was by using an universal goniometer and an electronic inclinometer. Results: The Pearson product-moment correlation between the two instruments was 0.78~0.80. The ICCs for inter-tester reliability ranged from 0.63 to 0.73 for universal goniometer and ranged from 0.81 to 0.88 for electric inclinometer. The ICCs for intra-tester reliability showed a wide variation(ICC=0.61 to 0.86). Conclusion: These findings indicate that the two instruments are reliable instruments for measuring ankle joint range of motion. The results also indicate that the two instruments can be used interchangeably for measuring ankle motions.