| 摘要 |
PURPOSE:To prevent the generation of cracks at seals by forming a metal foil for power feeding by doping silicon to molybdenum. CONSTITUTION:The foil seal type incandescent bulb is composed of seals 21 and 22 of foil sealing structure, a filament 30, inner lead rods 41 and 42, outer lead rods 51 and 52, and metal foils 61 and 62 for power feeding. Since the metal foils 61 and 62 for power feeding are made by doping silicon to molybdenum, the doped silicon is oxidized earlier than the molybdenum when the temperature of the seals 21 and 22 is raised at the lighting, and a protective membrane ot silicon oxide is formed on the surface of the metal foils 61 and 62 for power feeding. As a result, when the temperature of the seals is raised high, a protective membrane of the silicon oxide is formed at first, and the molybdenum is hardly oxidized thereby. Consequently, the generation of cracks at the seals can be prevented. |
