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중공 음극 구조를 갖는 미세가공 대기압 방전 소자
- Alternative Title
- Geunyoung Kim
- Author(s)
- Geun Young Kim
- Alternative Author(s)
- Geunyoung Kim
- Advisor
- 양상식
- Department
- 일반대학원 전자공학과
- Publisher
- The Graduate School, Ajou University
- Publication Year
- 2012-02
- Language
- eng
- Keyword
- microdischarge; micromachining
- Alternative Abstract
- This thesis presents atmospheric pressure microplasma devices with hollow cathode structures. The microplasma is used to refer to discharges with dimensions ranging from a few micrometers to a few millimeters. Atmospheric-pressure plasmas have many applications such as thin film deposition, surface modification, light sources and bio-medical treatment. Microdischarge devices for atmospheric-pressure plasmas can be fabricated using micromachining technology. If the size is reduced, the high-pressure operation is possible. Micromachining technology can make it possible to accomplish this by reducing the hole diameter. Discharge devices with flexible hollow cathode structures were fabricated. The discharge device consists of three layers; an anode layer, an insulation layer and a hollow cathode layer. Hollow cathode discharges have the unique characteristics of a high current density compared with planar electrode discharges. It is considered that the main mechanism for the high current density is assumed to be the oscillatory motion of electrons between the opposite cathode fall regions of the hollow cathode. Discharge devices are fabricated by micromachining technology. Two types of discharge devices were fabricated for DC excitation; a hole type and a hollow cathode type. And the device of a hole cathode type is fabricated for AC excitation. First, the discharge device of a hole type with a thin anode layer was fabricated for DC excitation. The discharge device is composed of a thin anode, an insulator and a hollow cathode. The anode and hollow cathode are made of aluminum and nickel, respectively. Polyimide is chosen as an insulating material because of its excellent dielectric properties and good mechanical stability. The device has an array of 7 ？e 11 holes for the emission. The diameter of holes is 70 ？？m. The size of the flexible discharge device is 20 mm ？e 10 mm ？e 0.05 mm. The discharge test was performed in argon gas atmosphere at room temperature. For the apply voltage ranging from 230 to 280 V, the emission was observed. Second, the device of a hollow cathode type was fabricated for DC excitation. The anode and hollow cathode of the device are made of aluminum and nickel, respectively. The insulation layer is polyimide. The hole diameter and depth are 70 and 110 ？？m, respectively. The size of the discharge device is 9 ？e 9 ？e 0.13 mm3. The discharge test was performed in an argon gas chamber at room temperature. The discharge occurs when a voltage is applied between the anode and cathode. The current is measured during the discharge at various applied voltages. The discharge is observed at atmospheric pressure. Finally, the discharge device of a hole cathode type for AC excitation was fabricated and tested. The device consists of insulator between two nickel electrodes. The nickel anode is chosen for an improved lifetime compared to that of an aluminum electrode. The size of the device is 20 mm ？e 10 mm ？e 0.08 mm. The device has an array of 10 ？e 10 holes for the discharge. The hole diameter and depth are 100 and 40 ？？m, respectively. The size of the microdischarge device is 20 ？e 10 ？e 0.08 mm3. The discharge test was performed in an argon gas chamber at room temperature. The device is operated by AC voltage because it is useful for simultaneous operation of holes. Discharges of 87 holes are observed This study using the micro discharge device could be useful in various applications. The devices of three hollow cathode structures were fabricated using micromachining technology. The discharge of the fabricated devices was observed at atmospheric pressure.
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- Graduate School of Ajou University > Department of Electronic Engineering > 3. Theses(Master)
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