A main wall part is provided so as to surround an integrated circuit part. A sub-wall part which is in "L" shape is provided between each corner of the main wall part and the integrated circuit part. Therefore, even if the stress is concentrated due to heat treatment or the like, the stress is dispersed to the main wall part and the sub-wall part, and hence peeling between layers and a crack are unlikely to occur, as compared with the conventional art. Further, even if the crack and the like occur at the corner, moisture from the outside hardly reaches the integrated circuit part when the main wall part and the sub-wall part are coupled to each other. For this reason, it is possible to ensure an extremely high moisture resistance.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. application Ser. No. 10/349,934 filed Jan. 24, 2003, now U.S Pat. No. 7,129,565.
Priority Data
Mar 15, 2002 [JP] 2002-072737 Sep 30, 2002 [JP] 2002-286687
