| 摘要 |
PROBLEM TO BE SOLVED: To suppress detection accuracy from declining.SOLUTION: A recess 15, when viewed from the other face 10b side of a first circuit board 10, is made to a shape having only a side face that has two connection parts 15a connecting to the opposed side faces 10c, 10d of the first circuit board 10. This side face is made to a shape matching a linear virtual line L linking the two connection parts 15a, or a shape having a portion protruding to a diaphragm part 17 side and having only one instance of a portion whose distance to the virtual line L gradually becomes long and a portion whose distance to the virtual line L gradually becomes short. According to this, since the recess 15 does not have opposed side faces, foreign matter will in no case be caught. Therefore, it is possible to suppress detection accuracy from declining. |
