| 摘要 |
PURPOSE:To reduce the generation of leak at a sealed section and improve hermetical sealing performance in a cap by including a high melting point solder within solder in a sealing section. CONSTITUTION:High melting point solder 7, which has a higher melting point than that of back side solder, is applied in a ring shape in a gap at a sealing section between a base 3 and a cap 4. Solder 6 at the sealing section melts in such a manner that it envelops the high melting point solder 7. The high melting point solder 7 does not melt easily since it has a high melting point and remain unmelted in the gap of the sealing section. Furthermore, since the high melting point solder is contained therein, the sealing section solder 6 reduces its thickness at the sealing section so that the thickness of the sealing section solder 6 present between the high melting point solder 7 and the base 3 and the cap 4 is reduced to 10 to 20mum. This thickness is smaller than the size of solder crystal. Therefore, no cavity is generated in the sealing section during solidification, thereby improving the hermetical sealing performance. |
