| 摘要 |
PURPOSE:To obtain a package with highly reliable sealing capabilities by a method wherein a lid capable of ultraviolet transmission is fitted to the first of two steps formed in a package upper cover with some gap between the lid and step. CONSTITUTION:A lid 2, capable of ultraviolet transmission, is fitted into the first of the two steps built in an opening 8 in an upper cover 1' and the two are fixed immovable with an adhesive agent 3. A gap (a) not less than 5mum is allowed to exist between the lid 2 and the wall of the first step so that stress concentration on the wall may be prevented of heat-caused expansion. A gap (b) between the lower surface of the lid 2 and the second step needs to be not less than 100mum or the junction will not stand a shear to be generated in high-temperature environments. The adhesive agent 3 is not seen from outside when the inner diameter of a ring-shaped covering 10 fixed to the upper, outer periphery of the lid 2 is smaller than that of the second step. |
