Method of manufacturing liquid discharge head, and liquid discharge head

A method of manufacturing a liquid discharge head comprising a first flow-path substrate and a second flow-path substrate including:

• (a) a first substrate preparing step of providing an energy generating element for generating energy for discharging a liquid on a first surface of the first flow-path substrate;
• (b) a first film forming step of forming a first protective film covering at least a part of the first surface of the first flow-path substrate;
• (c) a second film forming step of forming a second protective film covering a second surface opposite to the first surface of the first flow-path substrate;
• (d) a bonding step of bonding the second surface of the first flow-path substrate and a third surface of the second flow-path substrate via an adhesive;
• and
• (e) a first film removing step of removing at least a part of the first protective film provided on the first surface of the first flow-path substrate, wherein
• the second film forming step and the first film removing step are performed in this order.

A liquid discharge head, comprising:

• a first flow-path substrate;
• and
• a second flow-path substrate, wherein
• the liquid discharge head is manufactured by a manufacturing method, comprising:
• (a) a first substrate preparing step of providing an energy generating element for generating energy for discharging a liquid on a first surface of the first flow-path substrate and forming a first flow path passing through from the first surface to a second surface opposite to the first surface in the first flow-path substrate;
• (b) a second substrate preparing step of forming a second flow path passing through from a third surface to a fourth surface opposite to the third surface in the second flow-path substrate;
• (c) a first film forming step of forming a first protective film covering at least a part of the first surface of the first flow-path substrate and a wall surface of the first flow path;
• (d) a first ashing step of ashing the second surface of the first flow-path substrate;
• (e) a second film forming step of forming a second protective film covering the second surface of the first flow-path substrate;
• (f) a bonding step of bonding the second surface of the first flow-path substrate and the third surface of the second flow-path substrate via an adhesive such that the first flow path and the second flow path communicate with each other;
• (g) a second ashing step of ashing the first surface of the first flow-path substrate;
• and
• (h) a hydrofluoric acid processing step of processing the first surface of the first flow-path substrate with hydrofluoric acid, wherein
• the second film forming step, the bonding step, the second ashing step, and the hydrofluoric acid processing step are performed in this order;
• and
• a chlorine composition ratio of the first protective film is 1% or less.