To provide an inkjet head unit that can suppress influence of a thermal expansion coefficient increased by polarization processing to thereby suppress a thermal expansion coefficient of an entire head, and can prevent interfacial separation between an adhesive and an end portion of the head due to thermosetting.
An end portion of a head chip 11 in a direction perpendicular to a polarization direction of an actuator layer of the head chip 11 and a protection cover member 6 are fixed to each other with an adhesive 8. An actuator substrate of the head chip 11 is so constituted that a thermal expansion coefficient of a base layer is smaller than that of the actuator layer in a direction perpendicular to the polarization direction of the actuator layer, and a thermal expansion coefficient of a cover substrate is smaller than that of the actuator layer in the direction perpendicular to the polarization direction of the actuator layer.
COPYRIGHT: (C)2010,JPO&INPIT
DEGUCHI HARUHIKO
Mitsuo Tanaka
Yukinori Nakakura