• Title, Summary, Keyword: through-thickness hole

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FCCL 제작 시 Cu Sputter 조건에 따른 Through Hole 특성 연구

  • Kim, Sang-Ho;Yun, Yeo-Wan
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • pp.15-16
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    • 2008
  • In case manufacturing COF, through hole should be made to be used for a pathway connecting the conductive layers of its both faces. In case Cu-plating inside of through hole with electroless plating way, contact between Cu and PI film gets bad to be fell apart from PI by the impact of applying to the electric devices. Therefore, after sputtering is applying on inner through hole, then a method to perform electroplating process. In this study, after changing sputtering condition to manufacture FCCL, we looked the changeability of the upper PI and inner hole Cu layers. Making use of RF Magnetron sputtering equipment, we coated Cu thin film and Cu-plated on it through electroplating. After cold-mounting the completed FCCL, we examined hole section through an optical microscope. From the result of test, with parameters deposition pressure and deposition time, both the thickness of the hole plated layer and PI plated upper layer increased at regular rate, increasing the thickness of Cu sputter layer. However, from the result of test in increasing RF-power, we could know the increment rate of hole plated layer is considerably greater than that of PI plated upper layer. Therefore, we finally acquired good result; if you want only to increase the plated layer of inner hole, it's much better to increase RF-power.

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Comprehensive investigation of buckling behavior of plates considering effects of holes

  • Mohammadzadeh, Behzad;Choi, Eunsoo;Kim, Woo Jin
    • Structural Engineering and Mechanics
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    • v.68 no.2
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    • pp.261-275
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    • 2018
  • A comprehensive study was provided to investigate the buckling behavior of the steel plates with and without through-thickness holes subjected to uniaxial compression using ABAQUS. The method was validated by the results reported in the literature. Using the critical stresses, the buckling coefficients ($K_c$) were calculated. The effects of inclusion of material nonlinearity, plate thickness (t), aspect ratio (AR), and initial imperfection on buckling resistance of the plate was studied. Besides, the effects of having the hole in the plate were also studied. The diameter of the hole was normalized by dividing by plate breadth and was given in the form of ${\alpha}$. Results showed that perforating one hole in the center of a plate increases the plate buckling resistance while the having two holes resulted in a decrease in the plate buckling resistance. The effects of hole eccentricity (Ecc) on the buckling resistance of the plate was studied. The position of the hole center was normalized by half of the plate breadth and length in X- and Y-directions, respectively. In this study, four cases of boundary conditions were considered, and the corresponding buckling behavior were studied combined with plate aspect ratio. It was observed that the boundary condition of the case I resulted in the highest buckling resistance. Finally, a comparison was made between the buckling behavior of the uniaxially and biaxially loaded plate. It was revealed that the buckling resistance of a biaxially loaded plate is lower half than half of that of the uniaxially loaded plate.

Stress concentrations around a circular hole in an infinite plate of arbitrary thickness

  • Dai, Longchao;Wang, Xinwei;Liu, Feng
    • Structural Engineering and Mechanics
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    • v.34 no.2
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    • pp.143-157
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    • 2010
  • This paper presents theoretical solutions for the three-dimensional (3D) stress field in an infinite isotropic elastic plate containing a through-the-thickness circular hole subjected to far-field in-plane loads by using Kane and Mindlin's assumption. The dangerous position, where the premature fracture or failure of the plate will take place, the expressions of the tangential stress at the surface of the hole and the out-of-plane stress constraint factor are found in a concise, explicit form. Based on the present theoretical solutions, a comprehensive analysis is performed on the deviated degree of the in-plane stresses from the related plane stress solutions, stress concentration and out-of-plane constraint, and the emphasis has been placed on the effects of the plate thickness, Poisson's ratio and the far-field in-plane loads on the stress field. The analytical solution shows that the effects of the plate thickness and Poisson's ratio on the deviation of the 3D in-plane stress components is obvious and could not be ignored, although their effects on distributions of the in-plane stress components are slight, and that the effect of the far-field in-plane loads is just on the contrary of that of the above two. When only the shear stress is loaded at far field, the stress concentration factor reach its peak value about 8.9% higher than that of the plane stress solutions, and the out-of-plane stress constraint factor can reach 1 at the surface of the hole and is the biggest among all cases considered.

Numerical Analysis of OLED Luminescence Efficiency by Hole Transport Layer Change (유기발광 소자의 수송층 두께 변화에 따른 수치적 해석)

  • Lee, Jung-Ho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.12
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    • pp.1341-1346
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    • 2004
  • The OLED research is gone for two directions. One is material development research, and another one is structural improvement part. All two are thing to heighten luminescence efficiency of OLED. n other to improve luminescence efficiency of OLED Electron - hole pairs must consist much more in the device Their profiles are sensitive to mobility velocity of electrons and holes. In this paper, we demonstrate the difference of velocity between hole and electron by experiments, and compare with a data of simulation and experiment changing hole carrier transport layer thickness, so we get the optimal we improve luminescence efficiency. We suggest improving the efficiency of OLEDS would be to balance the injection of electrons and holes into light emission layer of the device. And, we improve understanding of the various luminescence efficiency through experiments and numerical analysis of luminescence efficiency in variable hole carrier transport layer's thickness.

The Study of Luminescence Efficiency by change of OLED's Hole Transport Layer

  • Lee, Jung-Ho
    • International Journal of Precision Engineering and Manufacturing
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    • v.7 no.2
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    • pp.52-55
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    • 2006
  • The OLEDs(Organic Light-Emitting Diodes) structure organizes the bottom layer using glass, ITO(indium thin oxide), hole injection layer, hole transport layer, emitting material layer, electron transport layer, electron injection layer and cathode using metal. OLED has various advantages. OLEDs research has been divided into structural side and emitting material side. The amount of emitting light and luminescence efficiency has been improved by continuing effort for emitting material layer. The emitting light mechanism of OLEDs consists of electrons and holes injected from cathode and anode recombination in emitting material layer. The mobilities of injected electrons and holes are different. The mobility of holes is faster than that of electrons. In order to get high luminescence efficiency by recombine electrons and holes, the balance of their mobility must be set. The more complex thin film structure of OLED becomes, the more understanding about physical phenomenon in each interface is needed. This paper observed what the thickness change of hole transport layer has an affection through the below experiments. Moreover, this paper uses numerical analysis about carrier transport layer thickness change on the basis of these experimental results that agree with simulation results.

A Study on the Arc Position which Influence on Quality of Plug Welding in the Vehicle Body (차체 플러그 용접품질에 영향을 미치는 아크 위치에 대한 실험적 기초 연구)

  • Lee, Kyung-Min;Kim, Jae-Seong;Lee, Bo-Young
    • Journal of Welding and Joining
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    • v.30 no.3
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    • pp.66-70
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    • 2012
  • Welding is an essential process in the automotive industry. Most welding processes that are used for auto body is spot welding. And $CO_2$ arc welding is used in a small part. In production field, $CO_2$ arc welding process is decreased and spot welding process is increased due to welding quality is poor and defects are occurred in $CO_2$ arc welding process frequently. But $CO_2$ arc welding process should be used at robot interference parts and closed parts where spot welding couldn't. $CO_2$ welding is divided into lap welding and plug arc spot welding. In case of plug arc spot welding, burn through and under fill were caused in various welding environment such as different thickness combinations of base metal, teaching point, over the two steps welding and inconsistent voltage/current. It makes some problem like poor quality of welding area and decrease the productivity. In this study, we will evaluate the effect of teaching point through the weld pool behavior and bead geometry in the arc spot welding at the plut hole. Welding position is horizontal position. And galvanized steel sheet of 2.0mm thickness that has plug hole of 6mm diameter was used. Teaching point was changed by center, top, bottom, left and right of the plug hole. At each condition, the phenomenon of weld pool behavior was confirmed using a high-speed camera. As the result, we find the center of plug hole is the most optimal teaching point. In the other teaching point, under fill was occurred at the plug hole. This phenomenon is caused by gravity and surface tension. For performance of arc spot welding at the plug hole, the teaching condition should be controlled at a center of plug hole.

Preparation of CuO powder for electroplating using lead frame etching wastes

  • Lee, Seung Bum;Jung, Rae Yoon;Kim, Sunhoe
    • Journal of Industrial and Engineering Chemistry
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    • v.64
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    • pp.116-123
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    • 2018
  • A novel method for manufacture of copper(II) oxide for copper electroplating solution is proposed in this paper. The copper(II) oxide was produced through two chemical reaction steps without sintering process after refinement of waste lead frame etching solution. The experimental major parameters were the amount of additives for first and second step, sodium carbonate and sodium hydroxide, respectively, to evaluate reaction characteristics. Also, the liquidity (angle of repose), solubility to sulfuric acid, chloric ion concentration and thickness of dimple thickness of plating hole were verified for the physical properties of copper(II) oxide as electroplating material. The reaction molar ratio of sodium carbonate was low, and $Cu_2CO_3$ was generated more than $Cu(OH)_2$. The optimum reaction mole ratio of sodium carbonate to copper chloride was revealed as 1.5. The optimum usage of sodium hydroxide for manufacture of copper(II) oxide using basic copper carbonate, produced at first reaction step, was 150 g. In these conditions,the average particle size of copper(II) oxide, the dissolution time for sulfuric acid, and the angle of repose were $21.49{\mu}m$, 62 s, and $35.5^{\circ}$, respectively. The yield of copper(II) oxide was 98.0 wt.%, for this optimum usage. Also, the via-filling hole thickness was $13.5{\mu}m$, which satisfies general via-filling hole thickness range, less than $15{\mu}m$.

Measurement of Sea Ice Thickness in the Arctic Ocean Using an Electromagnetic Induction Instrument (전자기 유도 장비를 이용한 북극해 해빙의 두께측정)

  • Jeong, Seong-Yeob;Lee, Chun-Ju
    • Journal of the Society of Naval Architects of Korea
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    • v.49 no.2
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    • pp.189-195
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    • 2012
  • The ice trials of the first Korean icebreaking research vessel "ARAON" were performed at the Arctic Ocean in July-August 2010. The sea ice concentrations of Arctic Ocean were 4/10 to 10/10 and the range of sea ice thickness was roughly 1.0 to 3.5m. In this research, sea ice thickness characteristics at the old ice floes were determined from results of drill hole and apparent conductivity measurements. Especially we measured apparent conductivity using an electromagnetic induction instrument (EM31-MK2) and estimated the sea ice thickness through the empirical equation from Cold Regions Research & Engineering Laboratory, CRREL. The results of estimated sea ice thickness were compared to drill hole measurement results and then, we suggest the new empirical equation to estimate sea ice thickness of single layer type sea ice during the summer season of Arctic Ocean by curve fitting approach to these data.

Thickness Control of Electroplating Layer for Copper Pillar Tin Bump (구리기둥범프 용 전해도금 층 제어)

  • Moon, Dae-Ho;Hong, Sang-Jeen;Park, Jong-Dae;Hwang, Jae-Ryong;Soh, Dea-Wha
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.903-906
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    • 2011
  • The electroplating and electro-less plating methods have been applied for the high density chip interconnect of the Copper Pillar Tin Bump (CPTB) preparation. The CPTB was prepared, which had been electroplated about $100{\mu}m$ pitch of copper layer firstly, and then the Tin layer was deposited on the copper pillar surface to protect the oxidation of it. It was also very important to get uniform thickness of electroplated copper layer, though it was difficult and sensitive. In order to control the thickness distribution, it was examined that the current separating disk of Insulating Gate with a hole in the center was installed between electrodes. The current flows through the center hole of the Insulating Gate in the cylindrical electroplating bath and the other parts were blocked to protect current flowing. The main current flowed through the center hole of the Insulating Gate directly to the opposite electrode of wafer disk. As the results, it was verified that the copper layer was thick in the center part of wafer disk with distribution of thinner to the outer part toward edge.

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Robust Design for Showerhead Thermal Deformation

  • Gong, Dae-Wi;Kim, Ho-Jun;Lee, Seung-Mu;Won, Je-Hyeong
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.150.1-150.1
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    • 2014
  • Showerhead is used as a main part in the semiconductor equipment. The face plate flatness should remain constant and the cleaning performance must be gained to keep the uniformity level of etching or deposition in chemical vapor deposition process. High operating temperature or long period of thermal loading could lead the showerhead to be deformed thermally. In some case, the thermal deformation appears very sensitive to showerhead performance. This paper describes the methods for robust design using computational fluid dynamics. To reveal the influence of the post distribution on flow pattern in the showerhead cavity, numerical simulation was performed for several post distributions. The flow structure appears similar to an impinging flow near a centered baffle in showerhead cavity. We took the structure as an index to estimate diffusion path. A robust design to reduce the thermal deformation of showerhead can be achieved using post number increase without ill effect on flow. To prevent the showerhead deformation by heat loading, its face plate thickness was determined additionally using numerical simulation. The face plate has thousands of impinging holes. The design key is to keep pressure drop distribution on the showerhead face plate with the holes. This study reads the methodology to apply to a showerhead hole design. A Hagen-Poiseuille equation gives the pressure drop in a fluid flowing through such hole. The assumptions of the equation are the fluid is viscous-incompressible and the flow is laminar fully developed in a through hole. An equation can be expressed with radius R and length L related to the volume flow rate Q from the Hagen-Poiseuille equation, $Q={\pi}R4{\Delta}p/8{\mu}L$, where ${\mu}$ is the viscosity and ${\Delta}p$ is the pressure drop. In present case, each hole has steps at both the inlet and the outlet, and the fluid appears compressible. So we simplify the equation as $Q=C(R,L){\Delta}p$. A series of performance curves for a through hole with geometric parameters were obtained using two-dimensional numerical simulation. We obtained a relation between the hole diameter and hole length from the test cases to determine hole diameter at fixed hole length. A numerical simulation has been performed as a tool for enhancing showerhead robust design from flow structure. Geometric parameters for the design were post distribution and face plate thickness. The reinforced showerhead has been installed and its effective deposition profile is being shown in factory.

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