Patent ID: 7665826

Claim:
An inkjet printing head comprising: a substrate including a heater for causing thermal energy used for ejecting ink from a nozzle to act on the ink; and a valve retaining member including a movable valve which is provided corresponding to the nozzle, and which is capable of changing its position in response to generating a bubble in the ink accompanying the action of the thermal energy caused by the heater, wherein the substrate includes a seat to which the valve retaining member is attached, the valve retaining member includes a plurality of holes distributed on the valve retaining member and penetrating from a bottom surface attached to the seat, and to a top surface opposite the bottom surface, the valve retaining member is fixed to the substrate by adhesion portions formed by attaching a material having a thermal expansion coefficient equal to that of the seat so that the material is joined to the seat by passing through the hole from the top surface, and each adhesion portion is formed through multiple holes of the plurality of holes.