• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.156-160
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• 1994

Use of engineering ceramics has been increasing due to the outstanding physical and chemical properties. Conventional machining processes, however, are not applicable due to their hardness and brittleness. Laser cutting is a promising alternative for these ceramics. In this study, experimental data of CO $_{2}$ laser cutting of $Al_{2}$ $O_{3}$ and Si $_{3}$ N $_{4}$ are obtained to give a guide in the industry. Results of $Al_{2}$ $O_{3}$ cutting showed extreme weakness to thermal crack and it was found that pulsed beam has to be used for thick $Al_{2}$ $O_{3}$ specimen. Si $_{3}$ N $_{4}$ showed good results for both CW and pulsed beams. Using pulsed beam resulted narrower kerf width with increased surface roughness a nd reduced cutting speed. It was also found that a parameter call path energy is useful for representing minimum threshold value for possible cutting range with pulsed beam.

• 한국정밀공학회지
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• 제20권12호
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• pp.105-114
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• 2003

In this study, a dicing machine with vision system was built and an algorithm for automatic alignment was developed for dual camera system. The system had a macro and a micro inspection tool. The algorithm was formulated from geometric relations. When a wafer was put on the cutting stage within certain range, it was inspected by vision system and compared with a standard pattern. The difference between the patterns was analyzed and evaluated. Then, the stage was moved by x, y, $\theta$ axes to compensate these differences. The amount of compensation was calculated from the result of the vision inspection through the automatic alignment algorithm. The stage was moved to the compensated position and was inspected by vision for checking its result again. Accuracy and validity of the algorithm was discussed from these data.

• 한국정밀공학회지
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• 제13권1호
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• pp.29-37
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• 1996

In this study, PC controlled CNC automatic cutting system is developed. Technological introduction of the control process and the computer programming has made possible not only the automatic control for cutting processing unit but also the easy-to-use graphic software that enables the cutting process. This program involves shape part drawing and amendment, pattern reading and saving, reading Autocad file, nesting process, kerf compensation, automatic cutting path generation, NC file conversion and motor control. Software is devided into 3 modules for easy work. First step enables drawing, amendment and pattern making, followed by automatic nesting and cutting path generation with kerf compensation. In the final step, drawing data is transmitted for the resulting automatic cutting processes. This software would be applicated in gas cutting and textile cutting so that it improves the productivity of cutting process.

• 한국정밀공학회지
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• 제27권6호
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• pp.32-38
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• 2010

Laser material processing technology is adopted in several industry as alternative process which could overcome weakness and problems of present adopted process, especially semiconductor and display industry. In semiconductor industry, laser photo lithography is doing at front-end level, and cutting, drilling, and marking technology for both wafer and EMC mold package is adopted. Laser cleaning and de-flashing are new rising technology. There are 3 kinds of main display industry which use laser technology - TFT LCD, AMOLED, Touch screen. Laser glass cutting, laser marking, laser direct patterning, laser annealing, laser repairing, laser frit sealing are major application in display industry.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.350-353
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• 2005

It is a feature of primary importance for a backing material for circular saw blades having teeth which are tipped with cermet, that the steel has not a too high hardenability in order that the backing material shall not be completely hardened through brazing, welding or grinding, etc. in connection with the finishing operation in the manufacturing of circular saw blade. It is believed that V-(2Mo+W) added steel from this point of view had best conditions. Using V-(2Mo+W) added backing steel, the tool failure can be effectively prevented due to superior damping performance.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.950-953
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• 2005

This study presents development of a multi-way high speed pipe cutting machine to improve production rate of pipe cut pans. In this paper, structural and modal analysis for the developed machine is carried out to check safety of the machine design. The analysis is carried out by FEM simulation using the commercial software, CATIA V5. The machine is modeled by placing proper shell and solid finite elements. The final results of analysis are applied to the design of multi-way high speed pipe cutting machine and the machine is successfully developed.

• 한국정밀공학회지
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• 제5권1호
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• pp.71-77
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• 1988

This study applies dynamic deformation analysis to the rake face stress distribution of cemented carbide cut-off tools by turning, using a finite element method. The results are following: 1. The dynamic loaded state of a cut-off tool was very changeable for the first 0.6 seconds. Reaching the normal state, it became in active. 2. Chipping was influnced not only by the magnitude of stress but also by the abrupt change of tensile and compressive stresses. 3. The distribution chat of principal stress by dynamic load and the direction of resultant vector were almost constant regardless of load time.

• 한국정밀공학회지
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• 제18권1호
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• pp.117-122
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• 2001

Many kinds of channels are used in industrial equipment and production machinery. Although mechanical saw has been used to cut many sorts of channels, there is cost rise problem because of low productivity. Shearing of channel has a special place because it helps to cut expected shape and size easily. A channel cutting die set which can be mounted and used on a hydraulic press is developed to improve the productivity of channel cutting process. Mode for the channel cutting is divided into single cut and double cut method. This study use double cut method, and the developed channel cutting die set is composed of upper and lower die set. Shearing time can be reduced from 40 minutes to 20 seconds using the developed channel cutting die set. The productivity of channel cutting process can be increased with shearing time reduction as well as cost reduction.

• 한국정밀공학회지
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• 제12권6호
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• pp.105-111
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• 1995

The inverse dynamic equations for 5 link robot including a closed chain have been derived. The closed chain is virtually cut open, and the kinematics and dynamics of the virtual open chain robot are analyzed. The constraints are applied to the virtually cut joints by the Jacobian matrix which represents the configuration of the closed chain. The topology of tree structrued open chain robot is described by a FATHER array. The FATHER array of a link indicates the link tha tis connected in the direction of base link. Based on the inverse dynamic equations, the torque sensitivity models of the 5 link robot have been developed. The sensitivity models characterize the sensitivity of the driving torque with respect to the link parameters. All the procedures are illustrated through the 2 link robot.

• 한국정밀공학회지
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• 제10권3호
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• pp.231-238
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• 1993

Mold-marking industries currently demands to reduce the tooling costs and time in mold making and to improve the productivity and quality in injection molding process. These problems can be easily solved by the laminated injection mold which is made by laser cutting metal sheets and bonding them by the brazing. Comparing with the conventional mold making technology which mainly depends on the machining, the new thchnology enables an arvitary design of cooling circuit whithout any restrictions of geometry. Therefore, it will offer high production tata of the injection molding processes. This paper evaluates the conventional and laminated injection mold making processes with a simple molding geometry, and also the cooling efficienty of the kinds of mold with the filling and cooling analyses. The results show that the laminated injection mold process takes much shorter time in tooling and cooling, and distributes temperatures more uniformly than the conventional one.