• International Journal of Aerospace System Engineering
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• v.1 no.1
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• pp.44-47
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• 2014

This study proposes a development for the nano silver adhesive, which is applicable to high efficiency LED(light-emitting diode) light. The important issue of LED light is heat exhaust from LED. Generally, the middle area of LED light is increased up to 380K. Therefore, the bottleneck between LED chip and heat sink are caused by high temperature. In this work, the adhesive material between LED Chip and heat sink was newly developed for improvement of bottleneck. The nano silver was adopted to solve heat problem of chip on board package for LED light. In order to evaluate the performance of the nano silver adhesive, the thermal analysis was performed. Moreover both adhesive performance and heat exhaust were verified through the prototype test. From the experimental test results, it is found that the developed nano silver adhesive has the high performance.

• Transactions on Electrical and Electronic Materials
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• v.16 no.6
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• pp.312-316
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• 2015

Through silicon via (TSV) technology holds the promise of chip-to-chip or chip-to-package interconnections for higher performance with reduced signal delay and power consumption. It includes high aspect ratio silicon etching, insulation liner deposition, and seamless metal filling. The desired etch profile should be straightforward, but high aspect ratio silicon etching is still a challenge. In this paper, we investigate the use of etch hard mask for finer TSVs etching to have clear definition of etched via pattern. Conventionally employed photoresist methods were initially evaluated as reference processes, and oxide and metal hard mask were investigated. We admit that pure metal mask is rarely employed in industry, but the etch result of metal mask support why hard mask are more realistic for finer TSV etching than conventional photoresist and oxide mask.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.2
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• pp.44-52
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• 2001

A modeling program was developed in Part I which represents the 3-D geometry, produces bill of material, automatically draws drawings and produces input data for structural analysis of Very High-rise Steel Artificial Reefs(VEHSAR). Model tests were carried out to measure drag forces acted on VEHSAR in the Ocean Engineering Wide Tank, the University of Ulsan and structural analyses were made to simulate structural behaviors of VEHSAR. The integrated package system is suggested to design VEHSAR with different geometries.

• Transactions on Electrical and Electronic Materials
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• v.15 no.4
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• pp.221-225
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• 2014

Although gold wire bonding techniques have already matured in semiconductor manufacturing, weakly bonded wires in semiconductor chip assembly can jeopardize the reliability of the final product. In this paper, weakly bonded or failed aluminum bonding pads are analyzed using X-ray photoelectron spectroscopy (XPS), Auger electron Spectroscopy (AES), and energy dispersive X-ray analysis (EDX) to investigate potential contaminants on the bond pad. We found the source of contaminants is related to the dry etching process in the previous manufacturing step, and fluorocarbon plasma etching of a passivation layer showed meaningful evidence of the formation of fluorinated by-products of $AlF_x$ on the bond pads. Surface analysis of the contaminated aluminum layer revealed the presence of fluorinated compounds $AlOF_x$, $Al(OF)_x$, $Al(OH)_x$, and $CF_x$.

• Toxicological Research
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• v.23 no.2
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• pp.173-177
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• 2007

The GLP contains specific language concerning characterization of the test, control and reference substances used in toxicity studies. This paper will describe and discuss what types of documents are required to support test/reference substance characterization under GLP system. The purpose of this article is to present an overview of data needed in the characterization package that will adequately define the substance. Most sponsors use a certificate of analysis (COA) to communicate the test sub-stance characterization status information to the contracting research organizations. The COA should provide the test $material^{\circ}{\phi}s$ characterization results, substance storage requirements, expiration dates, verification of the collection of the retention sample, archival location of the data to support the characterization and GLP compliance status of the characterization.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10b
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• pp.63-66
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• 2003

Forged gears have the obvious advantages with the greater utilisation of raw material and high productivity over the machined gears. The forged bevel gear has been used in differential gear for automotive with a high reliance. On the other hand, the studies have been continued to improve the accuracy and expand the applying areas. In this paper, a whole manufacturing process for forged gear from die design and cold forging to heat-treatment was introduced. The stress and elastic deformation for forging die have been analysed by the 3D-FEM-package. The real elastic deformation of die was measured by the strain-gages. The elastic deformation of die was reached to 1mm, in terms of the present study. The analysed quantitative dimension of die was taken into consideration into the CAD/CAM data for forging die.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.6
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• pp.56-62
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• 2008

An Allium-odorum is difficult material to handle because it is soft and weak mechanically. For bundling work of allium-odorum, we must grip in the bundle shape of unit weight. However it is difficult to grip allium-odorum by hand because the bundle bulk is very big. Especially, in packing work, the bundle shape of allium-odorum package is more important than other vegetables because the sale price depend on the bundle shape. In this paper, we propose bundling mechanism for a rectangular shape, and semi-auto bundling mechanism by a eccentric roller and a triangular link. We carry out mechanical model and analysis respectively using the CATIA V5 and SimDesigner. We have manufactured the prototype of the semi-automatic bundling machine, and got satisfied result through field test. This machine is in the process of commercialization.

• Laser Solutions
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• v.2 no.1
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• pp.38-42
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• 1999

As very large scale integration technology has been developed, much more accurate, reliable technology is needed for outer lead bonding. Laser soldering has been researched as an alternative for fine pitch device bonding. This study is focused on how to select optimal laser soldering variables with which solder wets parent material, the microstructural results of laser soldering and the reliability test One of popular packages, QFP100 was soldered successfully with two kinds of solder. The inspection of the joint for reliability was carried out by optical microscope, SEM, EDAX and pull test, which demonstrated the superiority of laser soldering.

• Laser Solutions
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• v.11 no.1
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• pp.7-11
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• 2008

Decapsulation technology is useful to inspect EMC of package device and the etching technology enable to check inside of device by removing plastic molding. Chemical etching method is used widely to fabricate a lot of semiconductor. But the method has some disadvantage due to wet process. Proposed method in this paper shows the application possibility such as fast processing time, processing accuracy and dry process. These result was obtained by directly removing of packed EMC using UV laser.

• Journal of the Microelectronics and Packaging Society
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• v.24 no.1
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• pp.35-43
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• 2017

The three-dimensional integrated circuit (3D-IC) is a general trend for the miniaturized and high-performance electronic devices. The through-silicon-via (TSV) is the advanced interconnection method to achieve 3D integration, which uses vertical metal via through silicon substrate. However, the TSV based 3D-IC undergoes severe thermo-mechanical stress due to the CTE (coefficient of thermal expansion) mismatch between via and silicon. The thermo-mechanical stress induces mechanical failure on silicon and silicon-via interface, which reduces the device reliability. In this paper, the thermo-mechanical reliability of TSV based 3D-IC is reviewed in terms of mechanical fracture, heat conduction, and material characteristic. Furthermore, the state of the art via-level and package-level design techniques are introduced to improve the reliability of TSV based 3D-IC.