| 摘要 |
A sealing substrate has first and second substrates. A hollow portion is formed in a first surface of the first substrate. The first substrate has a plate portion that forms a bottom surface of a hollow portion and a frame portion that forms an inner wall surface of the hollow portion. The second substrate is affixed to a second surface of the first substrate. The second substrate is formed of a material having a lower specific gravity than that of the first substrate. |
