• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.2
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• pp.45-51
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• 2003

The multi-piloting type progressive die for U-bending sheet metal production part is a very specific division. This study reveals the sheet metal forming process with multi-forming die by center carrier type feeding system. Through the FEM simulation by DEFORM, it was accepted to u-bending process as the first performance to design of strip process layout. The next process of die development was studied according to sequence of die development, i.e die structure, machining condition for die making, die materials, heat treatment of partially die components, know-how and so on. The feature of this study is the die development of scrapless progressive die of multi-stage through the modeling on the I-DEAS program, components drawing on the Auto-LISP, CAD/CAM application, ordinary machine tool operating and revision by tryout.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.4
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• pp.109-128
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• 2001

Bei vorliegender Arbeit wurde eine sogenannte Diskursstrukturgrammatik (DSG) vorgestellt, die auf die $Erkl\"{a}rung$ von verschiedenen diskursbezogenen $Ph\"{a}nomenen$ zielt, und derer Grundlage auf 'Head-driven Phrase Structure Grammar (HPSG)' basiert. Im Abschnitt 2 wurde die Syntax von DSG gegeben. Die Syntax besteht aus Grundsymbolen und Regeln. Die Grundsymbole teilen sich wiederum in grundlegende Diskurseinheiten und logische Konnektoren ein. Entsprechend der Syntax wurde die Semantik im Abschnitt 3 gegeben. Insbesondere habe ich das Diskursrelation­Prinzip aufgestellt, nach dem die Information eines Konnektoren die Bedeutung der neu gebildeten Diskurseinheit bestimmt. Im letzten Abschnitt 4 habe ich anhand der DSG zwei Beispiele analysiert, um zu zeigen, wie die DSG funktioniert. Von der Theorie aus gesehen, ist die vorgestellte DSG nicht $vollst\"{a}ndig$. Deshalb werde ich weiter die DSG systematisieren, indem ich andere $Ph\"{a}nomene$ im Bereich des Diskurses wie Anapher, Tempus usw. behandle

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.4
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• pp.43-49
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• 2004

The production parts have required multiple processes such as drawing, piercing, blanking and notching etc. are performed with a high production rates in progressive die. In order to prevent the defects of process result, the optimization of strip process layout design, die design, die making, and tryout etc. are needed. According to these factors of die development process, it has been required that the theory and practice of metal working process and its phenomena, die structure, machining conditions for die making, die materials, heat treatment of die components, processing know-how and so on. In this study, we designed and analyzed die components through the carrying out of upper relevant matters also simulated the strip process layout of multiple stage drawing by DEFORM. Especially the result of tryout and its analysis became to the feature of this study with a system of PDDC(Progressive Die design by computer).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.1121-1124
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• 2001

In this study, we verify th effects of pattern density on interlayer dielectric chemical mechanical polishing process based on the analysis of Preston's equation and confirm this analysis by several experiments. Appropriate modeling equation, transformed form Preston's equations used in glass polishing, will be suggested and described the effects of this modeling during pattern wafer ILD CMP. Results indicate that the modeling is well agreed to middle density structure of the die in pattern wafer, but has some error in low and high density structure of the die. Actually, the die used in Fab, was designed to have a appropriate density, therefore this modeling will be suitable for estimating the results of ILD CMP.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.05a
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• pp.86-91
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• 2002

The production part requiring multiple processes such as piecing, blanking and notching, are performed with a high production rates in progressive die. In order to prevent the dejects of process result, the optimum of strip process layout design, die design, die making, and tryout with inspection etc. are needed. According to these factors of die development process, they required theory and practice of metal working process and its phenomena, die structure, machining conditions for die making, die materials, heat treatment of die camponents, know-how and so on. In this study, we designed and analyzed die camponents also simulated the strip process layout of multiple stage drawing by DEFORM. Especially the result of tryout and its analysis become to the feature of this study.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.249-254
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• 2000

The contact forces between die components for the drawing of large size automotive panels introduce elastic deflections of the die components. Due to the deflections, the gap between blank holder and die varies locally resulting in nonuniform material flow. Such a nonuniform die gap usually requires correcting operation, so called die spotting, which is time consuming trial and error process. To reduce the die spotting time, the optimization of the blank holder bending deflection is needed. In this paper, we implemented an analysis procedure to predict the blank holder deflection. The analysis procedure and design of experiments techniques are applied to the optimization of balance block heights. The optimization results can be used as guidelines in actual die spotting process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.341-346
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• 2002

The production part requiring multiple processes such as piecing, blanking and notching are performed with a high production rates in progressive die. In order to prevent the defects of process result, the optimum of strip process layout design, die design, die making, and tryout with inspection etc. are needed. According to these factors of die development process, they required theory and practice of metal working process and its background, die structure, machining conditions for die making, die materials, heat treatment of die components, know-how and so on. In this study, we designed and analyzed die components also simulated the strip process layout of multiple stage drawing by DEFORM. Especially the result of tryout and its analysis become to the feature of this study.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.347-352
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• 2002

The Cut off-type progressive die for U-bending production part is a very specific division. This study reveals the sheet metal forming process with multi-forming die by Center Carrier type feeding system. Through the FEM simulation by DEFORM, it was accepted to u-bending process as the first performance to design of strip process layout. The next process of die development was studied according to sequence of die development, i.e. die structure, machining condition for die making, die materials, heat treatment of die components, know-how and so on. The feature of this study is the die development of scrapless progressive die of multi-stage through the Modeling on the I-DEAS program, components drawing on the Auto-Lisp, CAD/CAM application, ordinary machine tool operating and revision by tryout.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.4 s.37
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• pp.331-338
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• 2005

The rapid advances in high power light sources and arrays as encountered in incandescent lamps have induced dramatic increases in die heat flux and power consumption at all levels of high power LED packaging. The lifetime of such devices and device arrays is determined by their temperature and thermal transients controlled by the powering and cooling, because they are usually operated under rough environmental conditions. The reliability of packaged electronics strongly depends on the die attach quality, because any void or a small delamination may cause instant temperature increase in the die, leading sooner or later to failure in the operation. Die attach materials have a key role in the thermal management of high power LED packages by providing the low thermal resistance between the heat generating LED chips and the heat dissipating heat slug. In this paper, thermal transient characteristics of die attach in high power LED package have been studied based on the thermal transient analysis using the evaluation of the structure function of the heat flow path. With high power LED packages fabricated by die attach materials such as Ag paste, solder paste and Au/Sn eutectic bonding, we have demonstrated characteristics such as cross-section analysis, shear test and visual inspection after shear test of die attach and how to detect die attach failures and to measure thermal resistance values of die attach in high power LED package. From the structure function oi the thermal transient characteristics, we could know the result that die attach quality of Au/Sn eutectic bonding presented the thermal resistance of about 3.5K/W. It was much better than those of Ag paste and solder paste presented the thermal resistance of about 11.5${\~}$14.2K/W and 4.4${\~}$4.6K/W, respectively.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.229-233
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• 2000

In order to prevent the defects, the optimum design of the production part, strip process layout, die design, die making and try out etc. are necessary the analysis of effective factors. For example, theory and practice of metal shearing process and it's phenomena, die structure, machine tool working for die making, die materials and it's heat treatment, metal working in field, their know how etc. are included in those factors. In this study, we analyzed whole of data base, theoretical back ground of metal working process, and then performed the progressive die tryout with the screw press. Part2 of this study reveals with ultra precision progressive die design, its making and tryout.