| 摘要 |
The portions at the circumferential edges of a flow channel formation plate in which the corner portions of a dummy flow channel portion are formed are weaker than other portions, and thus when thermal stress has occurred due to temperature changes when the constituent elements of a flow channel unit are affixed to each other, cracks can be induced preferentially in the weak portion, rather than the other portions, starting from the ends of the corner portions. In particular, although similar corner portions are formed in a common liquid chamber, the intersection angle of the corner portions in the dummy flow channel portion is smaller than the intersection angle of the corner portions in the common liquid chamber, and thus it is easier for stress to concentrate in the corner portions of the dummy flow channel portion. |
