롤투롤 인쇄전자의 중첩정밀도 향상을 위한 비전 제어

최종근(Jong-Guen Choi),김형선(Hyung-Sun Kim),권오달(O-Dal Kwon) 산업기술교육훈련학회 2021 산업기술연구논문지 (JITR) Vol.26 No.1

Printed electronics involves the process of manufacturing electronic components, such as electronic circuits, sensors, devices, ultrathin films, and radio-frequency identifications using printing technology. Conductive electronic ink is used in these processes to form circuits similar to gravure printing or high-speed inkjet on the web in the form of plastic or thin films. Among the various techniques used for printing electronics, superposition printing control technology is the most valuable for forming multilayer circuits and determining the performance and added value of the product. This method of measuring superposition accuracy using charge-coupled device vision cameras is superior to other methods, such as infrared and ultrasonic sensors, in precision improvement because the vision system can simultaneously measure the positions of the web s direction and cross-direction travel. In this study, a control method using three vision cameras was installed before and after the second -stage-printing substrate rolling in a roll-to-roll printing electronic system to correct the superposition error. The application of the proposed method effectively improved the printing process precision. With superposition control using the vision cameras, superposition precision of up to 10-50 μm in two directions was achieved. It was shown that the precision of the roll-to-roll process could be enhanced effectively using this approach.

엔드밀 가공의 정밀도 향상을 위한 최적정삭여유에 관한 연구

최종근(Jong-Guen Choi),김형선(Hyung-Sun Kim),김성초(Sung-Cho Kim) 한국생산제조학회 2004 한국생산제조학회지 Vol.13 No.3

A significant error in the end milling processes is generated due to using slender tools of which the strengths are not sufficient. In order to obtain the desired machining accuracy, therefore, it is general that at first the rough cut is implemented, then the finish cut is followed. The rough cut eliminates large volume and the finish cut does the remained part. This remaining portion after the rough cut is called as the finish allowance. Larger finish allowances make it hard to get precise dimensions at a following finish cut. Smaller finish allowances are helpful for good dimension, but it sometimes is responsible for inferior surface qualities and over cuts. This study suggests a guidance for the optimum finish allowance for machining accuracy improvement, in which the rough cuts are regulated to remain the desired margins without any over cuts. Some experiments were carried out with various cutting conditions including the change of tool strengths and depth of cuts, and also extended to up millings as well as down millings.

엔드밀에 의한 슬롯가공의 최적화에 관한 연구

최종근(Jong-Guen Choi),김형선(Hyung-Sun Kim) 한국생산제조학회 2006 한국생산제조학회지 Vol.15 No.6

A slot cut in end milling processes is one of the laborious works because the cutting force is likely to deflect the tools excessively, then to make large errors or to fracture the tool. This difficulty is owing to the poor stiffness of slender shaped end mills. Though, in most cases, additional finish cuts are followed after rough cuts, the accuracy of rough cuts is still important because it affects the final accuracy after finish cuts and productivity. The accuracy in slot cuts depends on the tool stiffness and the cutting conditions including depth of cut and feed. In order to meet the desired accuracy, diameter of end mill and cutting allowance have to be selected carefully. This study suggests several guidances for selecting the end mill diameter and the slot cut allowance to improve machining accuracy and productivity in slot end millings. Some experiments were done with the various cutting parameters of tool diameter, depth of cut and feed.

엔드밀에 의한 슬롯가공의 가공특성

최종근(Jong-Guen Choi),김형선(Hyung-Sun Kim) 한국생산제조학회 2006 한국공작기계학회 춘계학술대회논문집 Vol.2006 No.-

In the end milling processes, the feature of end mills, which is slender and poor strength, is responsible to the most of machining errors. The end milling process is frequently used to cut complicated parts having slots. The slot cut by end mill is one of the laborious task because the cutting force is likely to deflect the tools and to make the errors. In order to meet the desired accuracy, therefore, the diameter of end mill and rough cut allowance have to be selected carefully. This study suggests a guidance for selecting the end mill diameters and the slotting allowances to improve machining accuracy in slot end millings. The investigation was carried out with various cutting conditions including change of tool strengths, depth of cuts, and extended to slotting allowance.

나사 리드 측정시스템 개발

최종근(Jong-Guen Choi),최현철(Hyeon-Cheol Choi),김형선(Hyung-Sun Kim) 한국생산제조학회 2007 한국생산제조학회지 Vol.16 No.5

This study proposes a new screw measurement system that is capable of measuring the pitch or lead of a screw, which is one of the most important parameters representing the screw quality. There are various conventional methods for screw measurement including some mechanical and optical ones, but they can not be applied to measure the lead except the profiles or sizes. The newly suggested method is able to measure the pitch or lead directly. This is executed by scanning the thread with a digital probe while the target screw rotates. The devised measurement system is a integrated computer system which is composed of a stepping motor, a digital linear gauge and a chuck device for holding the measured screw. In order to operate the system effectively and conveniently, a computer program having graphical user interface facility is developed. Some experiments were done to prove the effectiveness of the system.

Ti-6Al-4V 티타늄 합금의 공구 재종에 따른 선삭 특성

최종근(Jong-Guen Choi),김형선(Hyung-Sun Kim),정진오(Jin-Oh Chung) 한국생산제조학회 2008 한국생산제조학회지 Vol.17 No.2

Titanium and its alloys, due to their superior properties of high specific strength and excellent corrosion resistance, are increasingly used in living applications in the 21century. The applications in aerospace and medical industries demand machining process more frequently to obtain a desired product. But unfortunately, this material is one of the most difficult-to-cut. In the turning process of titanium alloys, the key point for successful work is to select proper tool materials and cutting conditions. This study suggests a guidance for selecting the tool materials and the cutting speeds to improve tool life and surface integrity in Ti-6Al-4V titanium turning process. The experiments investigate the change of surface roughnesses, cutting forces and flank wear with various cutting parameters of tool materials, depth of cuts and feeds. As the results, K10 type of insert tip was assured as the best for turning of Ti-6Al-4V titanium alloy.

롤 크리너의 선압 해석 및 측정

최종근(Jong-Guen Choi),최현철(Hyeon-Cheol Choi),이응기(Eung-Ki Lee) 한국생산제조학회 2006 한국공작기계학회 춘계학술대회논문집 Vol.2006 No.-

The impurities of roller surface affect directly the surface quality of the products obtained by rolling processes. As a devices to eliminate impurities on roller surface, the Roll Cleaner composes a blade being contacted to the roller surface during operating. In order to remove these impurities effectively, it is necessity to keep proper pressure between the cleaner blade and the roll surface. The Nip Pressure means this one. It is the most important parameter which decides the performance of roll cleaner, and depends upon several parameters including the cleaner design and the mechanical properties of blades. This study, first, analyzes the pressure generation mechanism for a roll cleaner developed commercially. Second, it suggests a technique for the measurement of nip pressure, which is useful to verify the performance of roll cleaners and their proper setup at factory floor.

인쇄전자를 위한 롤투롤 시스템의 필름 정밀제어에 관한 연구

김동민,최종근,김형선,Kim, Dong-Min,Choi, Jong-Guen,Kim, Hyung-Sun 한국생산제조학회 2010 한국생산제조학회지 Vol.26 No.1

RFID printing technology has emerged recently as an important tool for leading future IT. Therefore, many manufacturers concerning on low cost and mass production of the related products pay close attention to the printing technology. In order to realize printed electronics, the technologies for fine line-width/gap printing and registration are essential work. This study proposes a precise Roll to Roll control system that is capable of tilting two posts. Two controllable tilting posts can adjust film position at traverse direction for the precision registration. A mathematical model for representing the geometric features of each posts in Roll to Roll printing system is established first. Then an operating program is built to implement the system and to control film movement. For experimental test, a hard ware system is fabricated which is consisted of two AC servo motors, two posts tilting mechanisms, several guide rolls, and so on. The test results show the proposed system can control the film position precisely at transverse direction.

Ti-6Al-4V 티타늄 합금나사의 절삭 특성

김형선,최종근,김동민,류민영,Kim, Hyung-Sun,Choi, Jong-Guen,Kim, Dong-Min,Lyu, Min-Young 한국생산제조학회 2009 한국생산제조학회지 Vol.25 No.1

Titanium is one of the most attractive materials due to their superior properties of high specific strength and excellent corrosion resistance. The applications in aerospace and medical industries demand machining process more frequently to obtain more precise products. Machining of titanium is faced with strong challenges such as increased component complexity i.e. airframe components manufacturing processes. The machining cost on titanium have traditionally demanded high cutting tool consumable cost and slow machining cycle times. Similarly, the high wear of the cutting tools restricts the cutting process capabilities. Titanium screws applied to fasten parts In the several corrosion environment. In the thread cutting of titanium alloys, the key point for successful work is to select proper cutting methods and tool materials. This study suggests a guidance fur selecting the cutting methods and the tool materials to improve thread quality and productivity. Some experiments investigate surface roughnesses, cutting forces and tool wear with change of various cutting parameters including tool materials, cutting methods, cutting speed. As the results, the P10 type insert tip was assured of the best for thread cutting of Ti-6Al-4V titanium alloy. Also the initial depth of infeed was desirable to use the value below 0.5mm as the uniform cutting area method is applied.

Ti-6Al-4V 티타늄 합금나사의 절삭 특성

김형선(Hyung-Sun Kim),최종근(Jong-Guen Choi),김동민(Dong-Min Kim),류민영(Min-Young Lyu) 한국생산제조학회 2009 한국생산제조학회지 Vol.18 No.5

Titanium is one of the most attractive materials due to their superior properties of high specific strength and excellent corrosion resistance. The applications in aerospace and medical industries demand machining process more frequently to obtain more precise products. Machining of titanium is faced with strong challenges such as increased component complexity i.e. airframe components manufacturing processes. The machining cost on titanium have traditionally demanded high cutting tool consumable cost and slow machining cycle times. Similarly, the high wear of the cutting tools restricts the cutting process capabilities. Titanium screws applied to fasten parts in the several corrosion environment. In the thread cutting of titanium alloys, the key point for successful work is to select proper cutting methods and tool materials. This study suggests a guidance for selecting the cutting methods and the tool materials to improve thread quality and productivity. Some experiments investigate surface roughnesses, cutting forces and tool wear with change of various cutting parameters including tool materials, cutting methods, cutting speed. As the results, the P10 type insert tip was assured of the best for thread cutting of Ti-6Al-4V titanium alloy. Also the initial depth of infeed was desirable to use the value below 0.5mm as the uniform cutting area method is applied.