Patent ID: 8152278

Claim:
A liquid ejection head comprising: a first substrate; a rectangular liquid supply opening penetrating said first substrate; a plurality of recording elements, provided along a longitudinal direction of said liquid supply opening on a front side of said first substrate, for generating energy for ejecting liquid; a first penetrating electrode penetrating said first substrate from the front side to a back side thereof, for supplying electric power to said recording elements; a plurality of ejection outlets, provided corresponding to said recording elements, respectively, for ejecting the liquid; a flow path forming member for forming a flow path for fluid communication between said ejection outlets and said liquid supply opening; a second substrate having a front side supporting said first substrate at the back side of said first substrate, wherein said second substrate is made of the same material as said first substrate and is connected with said first substrate; a second penetrating electrode penetrating said second substrate from the front side to a back side thereof and electrically connecting with said first penetrating electrode; a plurality of openings, penetrating said second substrate and extending in fluid communication with said liquid supply opening, for supplying the liquid to said liquid supply opening; and a conductive layer provided between the back side of said first substrate and the front side of said second substrate and in direct contact with said first penetrating electrode and with said second penetrating electrode, wherein said first penetrating electrode, said second penetrating electrode and said conductive layer are made of the same metallic material.