Printing element substrate, liquid ejection head and inkjet printing apparatus

摘要

A recessed portion is provided on a shorter side of a rectangular liquid supply passage. Thereby a flow pathway by the recessed portion can be ensured, and even in a case where the air bubble is trapped to be closer to and in contact with one end of the liquid supply passage, a difference in flow resistance to two ink flows generated in this state can be made small. In this way, the flow speeds of the inks flowing in the periphery of the air bubble can be made small as a whole, and as a result, it is possible to suppress an ejection failure due to transfer of the air bubble to the ejection opening side or the like.

主权项

1. A printing element substrate in which an ejection opening for ejecting a liquid is provided, wherein the printing element substrate is provided with a liquid supply passage that is formed along a direction from a surface of the substrate at the opposite to a surface thereof where the ejection opening is provided to the surface where the ejection opening is provided, the liquid supply passage being shaped such that an area of a cross section along a direction perpendicular to the direction to the surface where the ejection opening is provided increases and after that, decreases, in the direction to the surface where the ejection opening is provided, and
the liquid supply passage has an opening end of a rectangular shape on the surface of the substrate at the opposite to the surface on the side where the ejection opening is provided, and a recessed portion, which has a certain depth in a direction toward the surface on the side where the ejection opening is provided, is formed on a shorter side in the rectangular shape, wherein a plurality of the recessed portions are provided on the shorter side in the rectangular shape.