| 摘要 |
PURPOSE:To obtain a stem characterized by direct sealing, few number of parts, no soldering and excellent heat radiating property, by forming a stem substrate by a mixture of copper and tungsten, and directly sealing lead wires made of Cobal through borosilicated glass in an airtight and insulated manner in through holes. CONSTITUTION:A stem substrate 20 is formed by a mixture of copper and tungsten. Lead wires 25 made of Cobal are sealed in through holes 23 by way of borosilicate glass 24 in an airtight and insulated manner. For example, the stem substrate 20 comprising the mixture of copper and tungsten has a flange at the peripheral part. A table shaped protruded part 22 for fixing elements is provided at the central part. The through holes 23 are provided in the vicinities of said table shaped protruded part 22. The lead wires 25 and 25 made of Cobal are sealed in the through holes 23 and 23 through the borosilicate glass 24 and 24. The stem substrate 20 is obtained by machining the mixture of fine powders of the copper and the tungsten by a powder molding method. |
