Patent ID: 8162444

Claim:
A printing head comprising: a printing element substrate comprising a printing element applying energy to a liquid for ejecting the liquid stored in a liquid chamber and an electrode electrically connected to a wire extending from the printing element for transmitting electrical energy to the printing element; a stud bump contacting with and bonded to the electrode; and a wiring substrate including a wire for transmitting electrical energy for driving the printing element and a lead formed at an end of the wire and connected with the stud bump, wherein in bonding portions between the electrode and the stud bump, only a part of contacting portions between the electrode and the stud bump is bonded, and between the electrode and the stud bump, when an area of portions in which the electrode and the stud bump are bonded is set as S 1 and an area of the contacting portions in which the electrode and the stud bump are contacted, but not bonded, is set as S 2 , a ratio of S 1 to S 2 is equal to or less than 1.0.