Liquid ejection head
A liquid ejection head includes a substrate, a piezoelectric element above the substrate, an orifice forming member above the substrate on the piezoelectric-element-provided-side, in which the orifice forming member has an ejection orifice for ejecting liquid and defines a pressure chamber between the orifice forming member and the substrate, and the pressure chamber communicates with the ejection orifice and includes the piezoelectric element therein, a first thin film provided between the substrate and piezoelectric element and defining a space between the first film and the substrate, and a second thin film on the piezoelectric element on the side opposite to the first film side and differing from the first film in rigidity. A communicating port is formed in the substrate in a region facing the space, communicates with the space through an opening having a smaller area than the area of the region, and is closed at an end.
1. A liquid ejection head comprising:
a substrate;
a piezoelectric element provided above the substrate;
an ejection orifice forming member provided above the substrate on a side on which the piezoelectric element is provided, the ejection orifice forming member having an ejection orifice configured to eject a liquid and defining a pressure chamber between the ejection orifice forming member and the substrate, the pressure chamber communicating with the ejection orifice and including the piezoelectric element therein;
a first thin film provided between the substrate and the piezoelectric element and defining a space between the first thin film and the substrate; and
a second thin film provided on the piezoelectric element at a side opposite to the first thin film side and differing from the first thin film in rigidity,
wherein a communicating port is formed in the substrate in a region facing the space, communicates with the space through an opening having a smaller area than an area of the region, and is closed at an end.
2. The liquid ejection head according to claim 1 , wherein the end of the communicating port is closed by a closing layer provided on the substrate on a side opposite to the side on which the piezoelectric element is provided.
3. The liquid ejection head according to claim 1 , further comprising:
a third thin film formed between the substrate and the space and protecting the substrate; and
a fourth thin film formed on an inner wall of the communicating port and protecting the inner wall.
4. The liquid ejection head according to claim 1 , wherein a wiring layer is formed in a region of the substrate, and the region faces the space.
5. The liquid ejection head according to claim 4 , wherein the wiring layer includes an integrated circuit.
6. A liquid ejection head comprising:
a substrate;
a piezoelectric element provided above the substrate;
an ejection orifice forming member provided above the substrate on a side on which the piezoelectric element is provided, the ejection orifice forming member having an ejection orifice configured to eject a liquid and defining a pressure chamber between the ejection orifice forming member and the substrate, the pressure chamber communicating with the ejection orifice and including the piezoelectric element therein;
a first thin film provided between the substrate and the piezoelectric element and defining a space between the first thin film and the substrate; and
a second thin film provided on the piezoelectric element on a side opposite to the first thin film side and differing from the first thin film in rigidity,
wherein a communicating port is formed in the first thin film in a region facing the space, communicates with the space through an opening having a smaller area than an area of the region, and is closed in an inside or at an end.
7. The liquid ejection head according to claim 6 , wherein the inside or the end of the communicating port is closed by a layer including the second thin film.
8. The liquid ejection head according to claim 7 , wherein the layer includes a material that electrically connects the piezoelectric element to the substrate.
9. The liquid ejection head according to claim 6 , further comprising a third thin film formed between the substrate and the space and protecting the substrate.