• 한국정밀공학회지
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• 제16권3호통권96호
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• pp.25-29
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• 1999

The lead frame manufactured by press stamping process, is an important part of semiconductor. The recent technical trend of semiconductor, chip sized and high performance package technology, requires the lead frame to be of more multi-leads and of fine ILP (Inner Lead Pitch). As the ILP is getting finer, its corresponding punch of the stamping die is getting narrower. The punch narrower than its stamping limit has been broken due to local buckling. This paper analyzed the phenomena of punch breakdown. Moreover, the punch design was modified to increase the critical limit of buckling force. This paper, also, suggested new design rules of the punch, which asks the modification of its lead frame design that has to be considered in the stage of semiconductor package design. The new design rules of lead frame design yields a good reliability of semiconductor package as well as a good quality of lead frame.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 추계학술대회 논문집
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• pp.233-234
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• 2009

• 한국기계가공학회지
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• 제12권6호
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• pp.84-92
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• 2013

This study improves the formability in fine-blanking the lock plate of car seat belts using a low carbon steel(SM35C) plate. The optimal die design for the forming process is proposed using rules for process planning based on theories and field experiences. The optimal design is analyzed using commercial finite element software in order to solve the fracture problems in the extrusion process. Through the improved layout based on the FEM results, the fracture of the extruded part and the roll over problem are solved. Furthermore, it is demonstrated through the shown from experiments that the extruded part does not break in the modified die.

• 한국정밀공학회지
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• 제22권2호
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• pp.126-132
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• 2005

In this paper, an auto-design system is introduced for a stamping tool based on commercial computer aided design system with its drafting language. The auto-design system consists of tool oriented product design subsystem which modifies and configures the product drawing, tool concept design subsystem which make a design of the punches and their punching progression and parts design subsystem that makes automatic dimension. The system is applied to the mechanical design of the stamping tool. The main logic of the system is based on half-edge theory, a kernel for the 3 dimensional CAD system, which is applied to 2 dimensional drafting auto-design system. The auto-design system enables to conspicuously reducing the designing time of the tool. In addition, there is little drafting error that had been about 3% without auto design program. It is effective to reduce the development time for new products because of rapid designing time of the tools, standardization of the stamping tool and the drafting rule for the auto-design system. The auto-design system yields high efficiency of the tool manufacturing system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.792-795
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• 2002

In previous researches, it is reported that Ti-10Ta-10Nb is robuster than Ti-6A1-4V which is used as a biomaterial in a experiment of cytotoxicity. Ti-10Ta-10Nb has enough hardness to be required as a biomaterial because the change of its hardness can be controlled more than 100% according to heat treatment condition and manufacturing condition. There are many hardness changing condition including Cast Homogenization, Solution treatment. Forging, Rolling in this research. The changing form and amount of new Ti-10Ta-10Nb to be developed in this researches, are measured as quantitative. Specially, the changing hardness amount of the specimen that is manufactured in single phase temperature, i.e. 80$0^{\circ}C$, are measured in case of high temperature rolling and high temperature cast condition.

• 한국정밀공학회지
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• 제22권12호
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• pp.156-162
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• 2005

In this paper, we study the mechanism of lead deformation by numerically simulating the stamping process by means of a commercial finite element code. It is very important to analyze effects that the lead shape makes on the lead deformation, because the lead shape is often modified in order to minimize the deformation or to increase the buckling critical load of the punch. Therefore the stamping process, first, numerically simulated by considering as a quasi-static problem. Second, the effect on the lead deformation due to the lead shape variation, a linear lead geometry and a bent lead, was numerically analyzed and discussed. Finally, the punching order was optimized fur multi-lead generating stamping process. The results show that the bent lead is little bit more shifted than the linear lead after the punching process. But the bent lead is vertically less deformed than the linear lead. The punching order to successively generate the lead is good to keep the lead space uniform. The results will be very effectively applied for the design of the blanking or punching dies in industry.

• 한국산학기술학회논문지
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• 제15권5호
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• pp.2567-2572
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• 2014

본 연구개발은 PCB소자 분리에 있어 개별적 레이저 커팅의 문제점을 개선하는 것으로, 다수개의 PCB소자가 결합된 PCB시트를 단시간에 커팅 할 수 있는 멀티지그 개발이 목적이다. 설계는 베이스프레임에 PCB서포터가 안착, 모델별 PCB서포터가 분리가능하게 설계 하였으며, 상부 레이저 투과공의 고정을 위하여 네오디움 자석을 양쪽에 각각 채택 지그를 완료 하였다. 개발성과는 하나의 베이스프레임으로 다양한 규격의 PCB소자 및 모듈의 고정과, PCB소자에 연결된 브릿지의 컷팅작업이 가능하도록 설계, 프레임제작과 교체에 소요되는 시간과 비용을 줄여 생산원가의 절감형 지그 개발로, 기존 타발식에 비해 정밀도 약 70% 상향 및 시설 투자비 약 400%를 절감하였다.