| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve reliability with reproducibility, to secure the positioning of a positive electrode in a support part, and to aim at economical production by inserting a pure metal material between an emission positive electrode and a support part so as to facilitate the soldering. SOLUTION: A metallic transporting material 8, which is chemically neutral and with which soldering of both an emission positive electrode and a support part can be performed at a sufficiently low temperature so as to prevent the deterioration of the emission characteristic of the positive electrode, is inserted between the emission positive electrode 1 and the support part 13. A selected material has a melting point between the operating temperature of a negative electrode and the operating temperature of the metal which forms the positive electrode. The material 8 provided as a boundary between the positive electrode 1 and the support part 13 is formed into the form of a metal powder, a ribbon or a wire. Especially, the material 8 is directly coated by vacuum evaporation on the support part 13 so as to restrict the quantity of the material 8 at the minimum so as to lower the weight and dimension of the negative electrode in view of heat output. Thermal output characteristic of the negative electrode is not influenced by the thickness of the material 8, and the thickness is set at a value, which can obtain the excellent soldering characteristic between the positive electrode 1 and the support part 13.</p> |
