New patent application published for: FLOW PATH MEMBER, MANUFACTURING METHOD OF FLOW PATH MEMBER, AND LIQUID EJECTION HEAD

FLOW PATH MEMBER, MANUFACTURING METHOD OF FLOW PATH MEMBER, AND LIQUID EJECTION HEAD

Claims

1. A flow path member comprising: a first substrate having a first flow path; a second substrate having a second flow path and stacked on the first substrate; a film member arranged between the first substrate and the second substrate, in which a plurality of through holes that allow the first flow path and the second flow path to communicate with each other are inlcuded; and an adhesive that adheres the first substrate and the film member, wherein a liquid flows from the first flow path to the second flow path via the through holes, an inner wall of the through holes includes a region where a diameter becomes smaller from the first substrate side toward the second substrate side, and at least one through hole among the plurality of through holes is blocked by the adhesive that has entered at least a part of the region.
2. The flow path member according to claim 1, wherein the film member is a flexible film.
3. The flow path member according to claim 2, wherein in the region where the diameter of the through hole becomes smaller, an angle between a hole surface of the through hole and the inner wall is 150° or more.
4. The flow path member according to claim 3, wherein in the region where the diameter of the through hole becomes smaller, a position of a minimum portion of the diameter is a portion adjacent to the second flow path side of the through hole.
5. The flow path member according to claim 4, wherein in the region where the diameter of the through hole becomes smaller, a value of a diameter of the minimum portion is 30 μm or less.
6. The flow path member according to claim 1, wherein a ratio (W1/W2) of a value W1 of a diameter of a maximum portion and a value W2 of a diameter of a minimum portion of the through hole is 1.1 or more.
7. The flow path member according to claim 6, wherein the ratio (W1/W2) of the value W1 of the diameter of the maximum portion and the value W2 of the diameter of the minimum portion of the through hole is 1.1 or more and 3.0 or less.
8. The flow path member according to claim 1, wherein if a film thickness of the adhesive that has entered the through hole is A and a film thickness of the film member is B, A/B ≥ 1/3 is satisfied.
9. The flow path member according to claim 8, wherein the film thickness of the film member is 3 μm or less.
10. The flow path member according to claim 9, wherein the film member is polyimide.
11. A manufacturing method of a flow path member, comprising: preparing a first substrate having a first flow path; forming a film member on a support substrate, including forming a plurality of through holes having a region where a diameter becomes smaller toward the support substrate in the film; applying an adhesive to the first substrate and attaching the first substrate and the film member on the support substrate via the adhesive; curing the adhesive; and removing the support substrate, wherein in attaching the film member, the through hole is blocked by the adhesive that has entered at least a part of the region.
12. The manufacturing method of a flow path member according to claim 11, wherein the step of forming the plurality of through holes is performed using an etching mask, and an etching selection ratio between the etching mask and the film member is 0.5 or less in a case where the plurality of through holes is formed.
13. A liquid ejection head comprising: a plurality of ejection ports; a first substrate having a first flow path; a second substrate including a second flow path communicating with the plurality of ejection ports; a film member arranged between the first substrate and the second substrate, in which a plurality of through holes that allow the first flow path and the second flow path to communicate with each other are included; and an adhesive that adheres the first substrate and the film member, including a flow path member in which a liquid flows from the first flow path to the second flow path via the through holes, wherein an inner wall of the through holes includes a region where a diameter becomes smaller from the first substrate side toward the second substrate side, and at least a part of through holes among the through holes are blocked by the adhesive that has entered at least a part of the region.
14. The liquid ejection head according to claim 13, wherein the through hole blocked by the adhesive is a through hole located at a corner of a region where the through holes are arranged.