IMPREGNATED CATHODE STRUCTURE

摘要

PURPOSE:To obtain good soldering between a cathode base and a cup and to achieve stable characteristic, by placing a metal wire mesh having high melting point and a brazing material composed of white metal or its alloy between a cathode base and a cup. CONSTITUTION:W wire mesh 32 containing Re is secured tightly through Mo-Ru brazing material 33 mixed with an organic binder to a thin substrate 31 obtained by cutting a porous W rod which is sintered after compressing W powder. Then the outside portion is removed such that the surface portion of the mesh 32 is exposed. Thereafter it is heated under reductive ambient to perform the brazing work. Then said substrate is cut to predetermined shape to produce a cathode member 41 which is welded through resistor welding with Mo cup 42 to produce an impregnated cathode structure. Consequently defective welding is eliminated and the yielding is improved while good characteristic can be maintained when it is fixed to an electron tube and operating.