METHOD OF HERMETICAL CONNECTION BETWEEN CERAMIC PART AND METAL PART

PURPOSE: To provide a method for connecting a ceramic part and a metal part, making a gap between them gas-tight by directly sintering a metal tube, having a coefficient of thermal expansion smaller than that of a ceramic container which has a specific coefficient of thermal expansion with an opening of the container via an end plug and also by introducing a metal part into the metal tube with its outer end closed. CONSTITUTION: A discharge tube 1 is made of Al2 O3 ceramics, having a thermal expansion coefficient of about 6.5 to 9×10 . An end 2 is sealed with an end plug 3 which is made of transition ceramics with a molybdenum tube (MP) 4 sintered directly in its inside surface. Once evacuated through the opening end of MP4, the inside of the discharge tube 1 is filled with inactive ignition gas, mercury and pill-like metal halide or the like. An electrode system 5 comprises a molybdenum pin 6 with a protrusion 7, an electrode center pin 8 made of tungsten, and a filament 9. After the electrode system 5 is introduced into MP4, the molybdenum pin 6 and MP4 are sealed at a circular gap of the outer edge by laser beam welding, hence completing final sealing.