Element substrate, liquid discharge head, and manufacturing method of same

A liquid discharge head that discharges liquid to a recording material comprising:

• an element substrate including
• a substrate,
• an energy generating element that generates energy used to discharge the liquid,
• circuit wiring that has an electrode portion for external electrical connection and that drives the energy generating element, and that is implemented on the substrate,
• a first protective film layer that has an opening portion for exposing the electrode portion and that covers the circuit wiring,
• an electroplating ground layer formed on the electrode portion, and
• an electroplated bump layer made of a metal material formed on the electroplating ground layer,
• in which element substrate a bent portion is formed in the first protective film layer by the first protective film layer covering a protruding portion that the circuit wiring has;
• a relay wiring portion provided with a lead connecting to the electrode portion;
• and
• a casing that internally stores the liquid to be supplied to the element substrate,
• wherein
• a second protective film layer is formed on the first protective film layer and covers the bent portion on the element substrate.

A manufacturing method of an element substrate used in a liquid discharge head that discharges liquid to a recording material, the element substrate including

• a substrate,
• an energy generating element that generates energy used to discharge the liquid,
• circuit wiring that has an electrode portion for external electrical connection and that drives the energy generating element, and that is implemented on the substrate,
• a first protective film layer that has an opening portion for exposing the electrode portion and that covers the circuit wiring,
• an electroplating ground layer formed on the electrode portion,
• an electroplated bump layer made of a metal material formed on the electroplating ground layer, and
• a bent portion formed on the first protective film layer by the first protective film layer covering a protruding portion that the circuit wiring has,
• the manufacturing method of the element substrate comprising the steps of:
• stacking, of forming a stacked structure of the circuit wiring made up of a plurality of film layers including the energy generating element on the substrate, and covering the circuit wiring by the first protective film layer with the electrode portion exposed from the opening portion;
• electroplating, of forming the electroplating ground layer on the electrode portion, and forming the electroplated bump layer on the electroplating ground layer by electroplating;
• and
• protective film forming, of forming, following the electroplating, a second protective film layer that covers a bent portion, formed at a periphery of the opening portion of the first protective film layer by a protruding portion that the circuit wiring has, being covered by the first protective film layer in the stacking.