• Design & Manufacturing
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• v.11 no.2
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• pp.9-14
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• 2017

The design and manufacturing tehcnology of IC sockets beyond 0.3mm pitch were presented. We compared the developed IC socket with the conventional one especially on the core metal-insulation part. Advanced machining techniques were employed to provide high precision. Our wire electrodischarge machining and high speed machining centers were able to maintain the micro-scale precision. We performed an injection molding analysis using a commercial analysis tool to predict the performance of the developed IC socket. We found that the solidification of the plastic resin and the high level of the clamping force are responsible for the defects such as incomplete filling and short shot. From these results, we modified the IC socket and successfully remove the defects. We were also able to find out that the new design socket needs less maintenance cost.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.158-165
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• 1995

G7 프로젝트로 개발중인 첨단생산시스템(FMS로부터 CIM까지)의 핵심구성요소인 고성능.고정밀공작기계의 성능을 평가할 수 있는 요소를 개발하고 사례로서 이를 Machining Centers에 적용하여 각 요소별 세부항목과 기준을 개발하여 제안하였다. 또한 이 평가내용을 국제경쟁제품과 비교하거나 국제경쟁력 달성정도를 평가할 때 용이하게 사용할 수 있는 적절한 평가모형도 제안하였다.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.1096-1101
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• 1992

In order tominimize fixing error of workpieces, circle, prismatic, sphere, cylindrical and sculptures types. Modification Rule by Indexing Table and Modification Rule by NC Program are developed for machining centers by using touch trigger probes. The Modification Rule by Indexing Table meas the alignment of workpiece to NC program through degree of freedoms of indexing table. The Modification Rule by NC Program is the alognment of NC program to workpiece ste-tp condition via the generation of NC progarm. A postprocessing module is alos developed for generating NC-part program(User Macro) to compensate for machining errors in end milling and boring processes. Developed method are verified by experiments.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.11
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• pp.112-119
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• 2002

Generally, it is very difficult to inspect geometric shape of large 2D objects after machining. To maintain the accuracy for inspection, a robot vision is used to divide overall shape into several enlarged images, and image processing technique is applied to acquire one minute geometric contour. The inspection is to compare the NC data with the measured contour data by the vision system, and the algorithm is to rotate to minimize the maximum deviation after coinciding two geometric centers. This paper experimentally shows that the proposed algorithm is very useful for inspection of large machined objects.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1028-1032
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• 1995

This paper describes the manufacture of spherical and aspherical surface on glass, superalloy and ceramic components. The rotationally symmetricallenses, and the ceramic or superalloy molds with spherical shapes are mainly generated by cutting processes on CNC lathe machine or 4,5 axis CNC machining centers. Recently, spherical shape parts require more precise and efficent machining technologies for wide material range such as optical lens of the lithography device in semiconductor manufacturing processes or the high precision mold machining of anti-chemical, anti-wear materials. In this paper, we introduce a newly developed infeed grinding machine with metal with metal bonded cup type wheel and its effects on spherical surface grinding.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.840-843
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• 1996

This paper presents an adaptive cutting force controller for milling process, which can be attached to most commercial CNC machining centers in a practical way. The cutting forces of X,Y and Z axes measured indirectly from the use of currents drawn by AC feed-drive servo motors. A typical model for the feed-drive control system of a horizontal machining center is developed to analyze cutting force measurement from the drive motor. The pulsating milling forces can be measured indirectly within the bandwidth of the current feedback control loop of the feed-drive system. It is shown that indirectly measured cutting force signals can be used in the adaptive controller for cutting force regulation. The robust controller structure is adopted in the whole adaptive control scheme. The conditions under which the whole scheme is globally convergent and stable are presented. The suggested control scheme has been implemented into a commercial machining center, and a series of cutting experiments on end milling and face milling processes are performed. The adaptive controller reveals reliable cutting force regulating capability under various cutting conditions.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.2
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• pp.46-52
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• 2004

The most of reducers consist of many gear parts, but a ball reducer never contains a gear. As the ball reducer with gearless has no back lash, it is necessary more and more to precision machine. The reducing of ball reducer happens by cycloid curves and all instant relative velocity centers always pass on a given constant position when rotational running. Then, it is difficult to calculate cycloid curve for design and machining. So, this paper studied a software for the design of the ball reducer design and machined all parts included among cycloid curve. By using the developed software, this study has large benefit to design every ball reducer.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.177-180
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• 2002

Generally, it is very difficult to inspect geometric shape of large 2D objects after machining. To maintain the accuracy for inspection, a robot vision is used to divide overall shape into several enlarged images, and image processing technique is applied to acquire one minute geometric contour. The inspection is to compare the NC data with the measured contour data by the vision system, and the algorithm is to rotate to minimize the maximum deviation coinciding two geometric centers. This paper experimentally shows that the proposed inspection algorithm is very useful fur a large machined object.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1991.11a
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• pp.121-125
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• 1991

In order to minimize fixing error of workpieces, prismatic and cylindrical types. Modification Rule by Indexing Table and Modification Rule by NC Program are developed for machining centers by using touch trigger probes. The Modification Rule by Indexing Table means the alignment of workpiece to NC program through degree of freedoms of indexing table. The Modification Rule by NC Program is the alignment of NC program to workpiece set-up condition via the generation of NC program. A postprocessing module is also developed for generating NC-part Program (User Macro) to compensate for Machining errors in end milling and boring processes. Developed methods are verified by experiments.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.3
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• pp.7-12
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• 2011

In the recent field of 5-axis machine tools, it is necessary to improve machining ability. The tilting index table is a key unit in order to manufacture some non-rotational and 3-dimensional parts by using conventional machining centers. In this study, the structural analysis of a tilting index table is carried out and the displacement and distribution of stress in the tilting index table is analysed to design the table safely. The modal analysis is performed in order to confirm the frequency response about the vibration having a large effect on the machine tools. The dynamic analysis is performed in order to confirm the rigidity, and the structural stability has been verified.