| 摘要 |
PURPOSE:To prevent an airtight sealing agent from being flowed in a case, by providing a groove along a frame of a box of the cover of a box shaped case. CONSTITUTION:A groove 33 is provided at the inside of a sealing frame of a cover 31 of an airtight case. Solder for an airtight sealing agent is attached to the cover in advance with plating. Airtight sealing is made by heating the cover and the airtight sealing case under vacuum. The molten solder tends to flow into the inside of the case, but it is kept in the groove 33. Thus, since the solder can not be invaded to the case, the reduction in the vacuum of the case due to gas generated from the solder can be avoided. As a result, the reliability of a piezoelectric oscillator can be improved. |
