| 摘要 |
PURPOSE:To obtain a stem which has preferable heat dissipation by forming a lead wirings passing hole and a block engaging hole at a stem body and engaging the element holding block with the hole. CONSTITUTION:A lead wirings passing hole 21 and a block engaging hole 22 are opened at a stem body 20 made of glass sealing Fe alloy or Fe. The hole 22 is a semicircular through hole, engages a block 23 of preferable thermoconductive material such as Cu or the like, and is formed so that the body 20 and the lower surface are aligned in the same plane. Lead wirings are passed via a glass sealing material 25 through the hole 21, and secured simultaneously upon soldering of the block 23. According to this structure, even if it is treated at a high temperature, the thermal expansion difference between the seal 25 and the body 20 is small. Accordingly, the lead wirings can be effectively secured, and since the end face of the block 23 is contacted directly with a heat radiator, the heat dissipation can be largely improved. |
