Method for manufacturing microprojection unit

A method for manufacturing a microprojection unit that includes

• a microprojection tool, and
• a base component, which is a member separate from the microprojection tool, the microprojection tool joined to a tip end of the base component,
• the microprojection tool including a base and a protrusion provided so as to stand up on an upper surface of the base,
• a base component having a liquid retention space in communication with the interior of the protrusion through the base,
• the manufacturing method comprising:
• a microprojection tool forming step including:
• bringing a projecting mold part into contact from one surface side of a base sheet including a thermoplastic resin, and thus forming a protrusion that protrudes from another surface side of the base sheet, and
• withdrawing the projecting mold part from the interior of the protrusion;
• a joining step of joining:
• the one surface side of the base sheet, in which the microprojection tool has been formed, and
• the tip end of the base component;
• and
• a cutting step of cutting the base sheet, to which the base component has been joined, along a contour of the base component at a position more inward than the base component's contour in a planar view of the base sheet as viewed from the microprojection tool side, to manufacture the microprojection unit;
• and
• wherein the one surface side of the base sheet, in which the microprojection tool has been formed, and the tip end of the base component are joined together by forming a continuous joined region in the microprojection unit while causing the base component's tip-end wall portion and a portion of the base sheet located on the tip-end wall portion of the base component's peripheral wall portion to melt, and wherein a width of the continuous joined region in a planar view from the microprojection tool side is from 1 to 3 mm, or
• wherein the one surface side of the base sheet, in which the microprojection tool has been formed, and the tip end of the base component are joined together by forming a continuous joined region in the microprojection unit while causing the base component's tip-end wall portion and a portion of the base sheet located on the tip-end wall portion of the base component's peripheral wall portion to melt, and wherein a spacing between the contour of the base of the microprojection tool and an outer-side peripheral edge of the continuous joined region is from 0.1 to 3 mm, or
• wherein the one surface side of the base sheet, in which the microprojection tool has been formed, and the tip end of the base component are joined together by forming a continuous joined region in the microprojection unit while causing the base component's tip-end wall portion and a portion of the base sheet located on the tip-end wall portion of the base component's peripheral wall portion to melt, and wherein a spacing between an inner-side peripheral edge of the continuous joined region and an inner wall of a tip-end wall portion of a peripheral wall portion of the base component is from 0.1 to 3 mm.