• Transactions of Materials Processing
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• v.23 no.8
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• pp.507-512
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• 2014

The objective of the current investigation is to establish techniques in micro pattern forming operations of polymeric circular tubes by using hydrostatic pressing. This method was developed and successfully applied to the micro pattern forming on polymeric plates. The key idea of the new technique is to pressurize multiple vacuum-packed substrate-mold stacks above the glass transition temperature of the polymeric substrates. The new process is thought to be a promising micro-pattern fabrication technique for two reasons; first, (hydro-) isostatic pressing ensures a uniform micro-pattern replicating condition regardless of the substrate area and thickness. Second, multiple curved substrates can be patterned at the same time. With the prototype forming machine for the new process, micro prismatic array patterns, 25um in height and 90 degrees in apex angle, were successfully made on the PMMA circular tubes with diameters of 5~40mm. These results show that this process can be also used in the micro pattern forming process on curved plates such as circular tube.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.64-67
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• 2009

Vibrational micro-forming of pyramidal shape patterns was conducted for an Al superplastic alloy, Al 5083 and a Zr-based bulk metallic glass, $Zr_{62}Cu_{17}Ni_{13}Al_8$. A vibrational micro-forming system was specially designed for generating vibrational load by combining a PZT actuator with a signal generator. Single crystal Si micro dies with wet-etched pyramidal patterns were used as master dies for vibrational micro-forming. The micro-formed pattern height was increasing with increasing the frequency of the vibrational load. In particular, the vibrationally-microformed pattern height was similar or even higher than the statically-microformed pattern height when the load frequency exceeded about 125 kHz. It was also observed that the crystal grains affect the surface quality of the microformed pattern and the distribution of the pattern height in the die cavity array.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.53-56
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• 2009

Roll forming process is one of important metal processing technology because the process is simple and economical. These days, roll forming process is tried to be employed in manufacturing the circuit board, barrier ribs and solar cell plate for productivity. However, it is difficult to apply to the forming of micro scale or sub-micro scale pattern. In this study, the roll forming processing for the micro scale is designed and analyzed. In this study, the forming of micro pattern for solar cell plate by incremental roll forming process is analyzed. The solar cell plate may have thousands of patterns, and the analysis of forming considering all the patterns is impossible due to the computational costs. In this study, analyses are carried out for various numbers of patterns and the results are compared. It is shown that the analyses results with four row patterns and twelve row patterns are same. So, it is considered that the analysis can be carried out for only four rows of pattern for the design of incremental roll forming process. Also experiment is carried out process that is designed through simulation.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.56-59
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• 2009

Roll forming process is one of important metal processing technology because the process is simple and economical. These days, roll forming process is tried to be employed in manufacturing the circuit board, barrier ribs and solar cell plate for productivity. However, it is difficult to apply to the forming of micro scale or sub-micro scale pattern. In this study, the roll forming processing for the micro scale is designed and analyzed. In this study, the forming of micro pattern for solar cell plate by incremental roll forming process is analyzed. The solar cell plate may have thousands of patterns, and the analysis of forming considering all the patterns is impossible due to the computational costs. In this study, analyses are carried out for various numbers of patterns and the results are compared. It is shown that the analyses results with four row patterns and twelve row patterns are same. So, it is considered that the analysis can be carried out for only four rows of pattern for the design of incremental roll forming process.

• Transactions of Materials Processing
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• v.19 no.3
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• pp.167-172
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• 2010

Roll-to-roll forming process is one of important metal processing technology because the process is simple and economical. These days, with these merits, roll-to-roll forming process is tried to be employed in manufacturing the circuit board, barrier ribs and solar cell plate. However, it is difficult to apply to the forming of micro scale or sub-micro scale pattern. In this study, the roll forming processing for the micro scale is designed and analyzed. The forming of micro pattern for small electric device such as LCD panel by incremental roll forming process is analyzed. Firstly, the optimum analysis conditions are found by several analyses. And then, formability is analyzed for various protrusion shapes at various forming temperatures. The formability is evaluated in terms of filling ratio and damage value. The filling ratio is defined from the tool geometry and critical damage is determined from the analysis of uniaxial tensile test. Finally, optimum forming conditions that guarantee the successful forming are found.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.05a
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• pp.379-382
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• 2007

The MEMS (Micro Electro Mechanical Systems) process is used in a micro/nano pattern manufacturing method. This method is based on the lithography technology. But the MEMS process has some problems such as complicated process, long processing time and high production costs. Many researchers are doing research in substitute manufacturing method to work out a solution to these problems. In this paper, we apply a dieless incremental forming technology to a substitute method of MEMS process. This dieless forming technology is using in the commercial scale sheet forming such as a prototype of automobile sheet parts. 5-axes CNC (Computerized Numeric Control) method are applied in this system to get a micro-scale dieless forming results. These 5-axes system are composed of precision AC servo motor stages (4-axes) and PZT actuator (1-axis). A PZT actuator is used in a precision actuating axis because it can be operated in the nano scale stroke resolution. This micro dieless incremental forming system has the advantage of minimization in manipulating distance and working space. As equipment and tools become smaller in size, minute inertia force and high natural frequency can be obtained. Therefore, high precision forming performance can be obtained. This allows the factory to quickly provide the customer with goods because the manufacturing system and process are reduced. To construct this micro manufacturing system, many technologies are necessary such as high stiffness frame, high precision actuating part, structural analysis, high precision tools and system control. To achieve the optimal forming quality, the micro dieless forming system is designed and made with high stiffness characteristic.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.107-108
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• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.491-492
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• 2010

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.254-258
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• 2009

In this paper, the low frequency vibration forming system is developed for micro-patterns formation on the metal substrate. many researchers have studied about micro-forming technologies such as micro deep drawing, press forming, forging, extrusion etc. for the formation of precise micro-patterns on the surface of metal substrates, multi-step forming process must be used to improve qualifies of the deformed patterns. Since the low frequency vibration forming system could easily deform the surface of metal substrates, several steps of multi-step forming process should be removed by using the low frequency vibration forming system. In order to find optimal process conditions, we have carried out low frequency vibration forming process with varying the vibration frequency from 110Hz to 500Hz.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.493-494
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• 2010