Liquid-repellent substrate, and ink jet head and production method therefor

A method of producing an ink jet head comprising:

• forming a substrate having an ejection orifice configured to eject an ink;
• forming an underlying film on an ink ejection surface side of the substrate, the underlying film containing a silicon atom (Si), a carbon atom (C), and an oxygen atom (O);
• and
• forming a liquid-repellent film on an ink ejection surface side of the underlying film,
• wherein an atomic composition ratio of the silicon atom in the underlying film is 19 atomic % to 26 atomic %,
• wherein an atomic composition ratio of the carbon atom included in the underlying film is 13 atomic % to 42 atomic %,
• wherein an atomic composition ratio of the oxygen atom included in the underlying film is 39 atomic % to 61 atomic %, and
• wherein the underlying film having a maximum peak P of a binding energy of a Si2p orbital of a surface part thereof measured by X-ray photoelectron spectroscopy satisfies formula (1):
• 102.9
• (
• eV
• )
• <
• P
• ≤
• 104.
• (
• eV
• )
• .
• (
• 1
• )

A liquid-repellent substrate comprising:

• a substrate;
• a liquid-repellent film;
• and
• an underlying film arranged between the substrate and the liquid-repellent film,
• wherein the liquid-repellent film forms a siloxane bond with the underlying film, and
• wherein the underlying film contains a silicon atom (Si), a carbon atom (C), and an oxygen atom (O), and a maximum peak P of a binding energy of a Si2p orbital of a surface part of the underlying film measured by X-ray photoelectron spectroscopy satisfies formula (1):
• 102.9
• (
• eV
• )
• <
• P
• ≤
• 104.
• (
• eV
• )
• .
• (
• 1
• )