A Micromachined Hollow Cathode Discharge Device for the Flexible Display

摘要

This paper presents the fabrication and experiment of a flexible micro hollow cathode discharge device. The device is composed of three layers which are a thin anode layer, a insulation layer and a hollow cathode layer. The micro hollow cathode discharge occurs between two electrodes that have an array of holes with the diameter of 70 μm. The device has an array of 7 x 11 holes. The hollow cathode discharge usually has a characteristic of the high current density. The device is fabricated by micromaching technology. The micro hollow cathode is made by means of nickel electroplating in the photoresist mold. The material of the thin insulator is polyimide. Polyimide is spin-coated on a nickel layer and the anode is fabricated by thermal evaporation of aluminum. The thickness of the flexible discharge device is 50 μm and total size of the device is 20 mm x 10 mm. The test set up consists of a direct current high voltage source, a ballast resistor, a gas chamber and a CCD camera. The discharge test was performed in argon gas chamber at room temperature for various pressures. We measured the current while the discharge occurs for various voltages applied. Compared with macro discharge devices, this device operates at much higher pressure, even at 1 atm. The discharge appears at the applied voltage of 0.23 kV in 260 mmHg. We observed the stable discharge. The device breaks down when the current is over 3 mA. The obtained current-voltage relationship is linear.