절삭공구 플랭크 마모의 광전자학적 측정 시스템 개발

전종업(Jong Up Jeon),김승우(Seung Woo Kim) Korean Society for Precision Engineering 1987 한국정밀공학회지 Vol.4 No.3

회전구동 정전형 마이크로 액추에이터를 이용한 고트랙밀도 HDD 용 이단 구동 시스템

전종업(Jong Up Jeon),정성환(Sunghwan Jung),최재준(Jae-Joon Choi),박지황(Jihwang Park),이창호(Chang-Ho Lee),김철순(Cheol-Soon Kim),민동기(Dong-Ki Min),김영훈(Young-Hoon Kim),이승희(Seung-Hi Lee) Korean Society for Precision Engineering 2005 한국정밀공학회지 Vol.22 No.10

This paper presents the design, fabrication, and testing results of a dual stage actuator system for a fine positioning of magnetic heads in magnetic disk drives. A novel rotary microactuator which is electrostatically driven and utilized as a secondary actuator was designed. The stator and rotor electrodes in the microactuator was revised to have the optimal shapes and hence produces much higher rotational torque compared with the conventional comb-shape electrodes. The microactuators were successfully fabricated using SoG(silicon on glass) processing technology, which is known as being cost-effective. The fabricated microactuator has the structural thickness of 45㎛ with the gap width of approximately 3㎛. The dynamic characteristic of microactuatorlslider assembly was investigated, and its natural frequency and DC gain were measured to be 304㎑ and 32㎛/V, respectively. The microactuatorlslider assembly was integrated into a HDD model V10 of Samsung Electronics Co. and a dual servo algorithm was tested to explore the tracking performance of dual stage actuator system where the LDV signals instead of magnetic head signals were used. Experimental res ults indicate that this system achieves the tracking accuracy of 30㎛. This value corresponds to a track density of 85,000 track per inch(TPI), which is about 3 times greater than that of current hard disk drives.

정전부상시스템의 설계

전종업(Jong Up Jeon) Korean Society for Precision Engineering 2008 한국정밀공학회지 Vol.25 No.6

Electrostatic forces have an advantage of directly levitating not only non-ferromagnetic metals but also semi-conductors, such as silicon wafers, and dielectric materials like glass. This paper describes the characteristics of electrostatic forces and electrostatic suspension system, followed by the basic principle of 1-DOF(degree of freedom) electrostatic suspension system, and the structures of electrodes-for-suspension and voltage supplying methods to the electrodes in 1-DOF model. This paper also discuss about the minimum number of electrodes needed to control n-DOF motion of the suspended object and represents some desirable electrode patterns to stabilize the 6-DOF motion of the object. In the near future, electrostatic suspension system is expected to be applied to industrial manufacturing processes, for example, to the manufacture of semiconductor devices and/or flat panel display devices.

릴레이 제어법을 이용한 실리콘 웨이퍼의 정전부상에 관한 연구

전종업(Jong Up Jeon),이상욱(Sang Uk Lee) Korean Society for Precision Engineering 2005 한국정밀공학회지 Vol.22 No.10

A simple and cost-effective method for the electrostatic suspension of thin plates like silicon wafers is proposed which is based on a switched voltage control scheme. It operates according to a relay feedback control and deploys only a single high-voltage power supply that can deliver a DC voltage of positive and/or negative polarity. This method possesses the unique feature that no high-voltage amplifiers are needed which leads to a remarkable system simplification relative to conventional methods. It is shown that despite the inherent limit cycle property of the relay feedback based control, an excel1ent performance in vibration suppression is attained due to the presence of a relatively large squeeze film damping origination from the air between the electrodes and levitated object. Using this scheme, a 4­inch silicon wafer was levitated stably with airgap variation decreasing down to 1 1㎛ at an airgap of 100 ㎛.

릴레이 제어법을 이용한 유연 판상체의 정전부상에 관한 연구

전종업(Jong Up Jeon),김선민(Sun-Min Kim) Korean Society for Precision Engineering 2006 한국정밀공학회지 Vol.23 No.6

A design and control of electrostatic suspension system for flexible objects is presented. A number of electrode pairs of which the number depends on the object flexibility are positioned above the object and the voltages applied to each electrode pair are controlled, independently on the others, on the basis of the gap length. To implement the system with low cost and compactness, switched-voltage control scheme that is based on the relay feedback control is utilized. Relay feedback control method deploys only a single high-voltage power supply that can deliver a DC voltage of positive and/or negative polarity and thus high voltage amplifiers that are costly and bulky are not needed any more. It is shown that despite the inherent limit cycle property of the relay feedback based control, an excellent performance in vibration suppression is attained due to the presence of a relatively large squeeze film damping originating from the electrodes and levitated object. Employing fourteen electrode pairs, a thin aluminum plate with a thickness of 0.1 ㎜ has been suspended at a gap length of 0.75㎜.

초소형 고밀도 정보저장장치를 위한 고종횡비의 팁을 갖는 정전 구동형 폴리 실리콘 프로브 어레이 개발

전종업(Jong Up Jeon),이창수(Chang-Soo Lee),최재준(Jae-Joon Choi),민동기(Dong-Ki Min),전동렬(Dongryeol Jeon) Korean Society for Precision Engineering 2006 한국정밀공학회지 Vol.23 No.6

In this study, a probe array has been developed for use in a data storage device that is based on scanning probe microscope (SPM) and MEMS technology. When recording data bits by poling the PZT thin layer and reading them by sensing its piezoresponse, commercial probes of which the tip heights are typically shorter than 3㎛ raise a problem due to the electrostatic forces occurring between the probe body and the bottom electrode of a medium. In order to reduce this undesirable effect, a poly-silicon probe with a high aspect-ratio tip was fabricated using a molding technique. poly-silicon probes fabricated by the molding technique have several features. The tip can be protected during the subsequent fabrication processes and have a high aspect ratio. The tip radius can be as small as 15 ㎚ because sharpening oxidation process is allowed. To drive the probe, electrostatic actuation mechanism was employed since the fabrication process and driving/sensing circuit is very simple. The natural frequency and DC sensitivity of a fabricated probe were measured to be 18.75 ㎑ and 16.7 ㎚/V, respectively. The step response characteristic was investigated as well. Overshoot behavior in the probe movement was hardly observed because of large squeeze film air damping forces. Therefore, the probe fabricated in this study is considered to be very useful in probe-based data storages since it can stably approach toward the medium and be more robust against external shock.

정전기력을 이용한 유리 판넬의 비접촉 지지 및 반송

전종업(Jong Up Jeon) Korean Society for Precision Engineering 2006 한국정밀공학회지 Vol.23 No.3

In the manufacture of liquid crystal display devices, there is a strong demand for contactless glass panel handling devices that can manipulate a glass panel without contaminating or damaging it. To fulfill this requirement, an electrostatic transportation device for glass panels is proposed. This device can directly drive a glass panel and simultaneously provide contactless suspension by electrostatic forces. To accomplish these two functions, a feedback control strategy and the operational principle of an electrostatic induction motor are utilized. The stator possesses electrodes which exert electrostatic forces on the glass panel and are divided into a part responsible for suspension and one for transportation. To accomplish dynamic stability and a relatively fast suspension initiation time, the structure of the electrode for suspension possesses many boundaries over which potential differences are formed. In this paper, an electrode pattern suitable for the suspension of glass panels is described, followed by the structure of the transportation device and its operational principle. Experimental results show that the glass panel has been transported with a speed of approximately 25.6 ㎜/s while being suspended stably at a gap length of 0.3 ㎜.

시간최적제어기법을 이용한 정전부상시스템에 관한 연구

전종업(Jong Up Jeon),백봉우(Bong Woo Baik),Hung Manh Ngo,박규열(Kyu Yeol Park) Korean Society for Precision Engineering 2008 한국정밀공학회지 Vol.25 No.3

A new method for the electrostatic suspension of disk-shaped objects is proposed which is based on a time-optimal control scheme and deploys only high-voltage power supplies that can deliver de voltages of positive and/or negative polarity. This method possesses the unique feature that no high-voltage amplifiers are needed which leads to a remarkable system simplification and objects can be suspended stably even in vacuum environment. Using this scheme, an aluminium disk used in a 3.5-inch HDD was suspended stably at an airgap of 0.3㎜.

릴레이 제어법을 이용한 유리패널의 정전부상에 관한 연구

전종업(Jong Up Jeon) Korean Society for Precision Engineering 2008 한국정밀공학회지 Vol.25 No.6

In the manufacture of flat panel display devices, there is a strong demand for contactless glass panel handling devices that can manipulate a glass panel without contaminating or damaging it. To fulfill this requirement, an electrostatic suspension device for glass panels where the glass panel is supported by electrostatic forces without any mechanical contact is proposed. To implement the system with low cost and compactness, switched-voltage control scheme that is based on the relay feedback control is utilized. Relay feedback control method deploys only a single high￢voltage power supply that can deliver a DC voltage of positive and/or negative polarity and thus high voltage amplifiers that are costly and bulky are not needed any more. It is shown that despite the inherent limit cycle property of the relay feedback based control, an excellent performance in vibration suppression is attained due to the presence of a relatively large squeeze film damping originating from the electrodes and levitated object. Using this scheme, a 100x100㎜² glass panel was levitated stably with airgap variation decreasing down to 1 ㎛ at an airgap of 100 ㎛.

주사전자현미경용 전자검출기의 설계 및 제작

전종업(Jong Up Jeon),김지원(Ji Won Kim) Korean Society for Precision Engineering 2008 한국정밀공학회지 Vol.25 No.4

Electron detectors used in scanning electron microscope accept electrons emitted from the specimen and convert them to an electrical signal that, after amplification, is used to modulate the gray-level intensities on a cathode ray tube, producing an image of the specimen. Electron detector is one of the key components dominating the performance of scanning electron microscope so that the development of electron detectors having high performance is indispensable to acquire high quality images using scanning electron microscope. In this paper, we designed and manufactured an electron detector and conducted a couple of image capture experiments using it. In particular, scintillator which generates light photons when it is struck by high-energy electrons was manufactured and experimental studies on the optimization of manufacturing condition was carried out. From experiments to evaluate the performance of our detector, it was verified that the performance of our detector is equivalent to or better than that of the conventional one.