Method for manufacturing liquid ejection chip and liquid ejection chip

A method for manufacturing a liquid ejection chip equipped with an ejection unit which is configured to be capable of ejecting a plurality of liquids, and a plurality of channels which are configured to separately store the plurality of liquids to be supplied to the ejection unit, the method comprising:

• filling a molten resin into a mold into which a substrate in which the ejection unit is installed on a first surface and a groove and a protrusion for forming the channels are formed on a second surface is loaded, and curing the molten resin, thereby forming a resin member on the protrusion with the molten resin, the resin member forming a partition separating a space within the channels adjacent to each other,
• wherein the partition extends in a filling direction of the molten resin, and
• wherein a cross-section area of the resin member corresponding to the partition at a cross section orthogonal to an extending direction of the partition decreases from an upstream side toward a downstream side of the filling direction.