| 摘要 |
PURPOSE:To make accurate and easy processing of magnetron cathode structure possible by forming a step portion by powder pressing at the fit portion of an upper shield for holding a supporting metal rod of the magnetron cathod structure. CONSTITUTION:An upper shield 12 for holding a cathod 11 made by winding a thin wire to a spiral shape has a circular flange 12a and a boss 12b and is also provided at its center portion with a through hole portion consisting of a large diameter portion 13a, a small diameter portion 13b, and a step portion 13c, and the top end of a center support 14 for holding the upper and shield 12 is inserted to the large diameter portion 13a until it bumps against the step portion 13c of the through portion to ensure keeping the positional relationship between the upper end shield 12 and the center support 14. The construction eliminates the necessity of providing a step portion to the center support 14, so that the center support 14 can be manufactured with high mass productivity and low cost, and the upper end shield 12 can be made of Mo power by press molding and burning thereafter, so that the two step holes with different diameters can be easily processed. |
