Joint body, manufacturing method for joint body, and manufacturing apparatus for joint body

A joint body comprising:

• a first metal member;
• a second metal member placed on the first metal member;
• and
• a joint portion including a welded portion where the first metal member and the second metal member are joined together, the welded portion having a line shape, wherein
• the joint portion includes:
• a first longitudinal portion extending in a first direction, the first longitudinal portion having first intersecting portions arranged in the first direction, the welded portion intersecting itself at the first intersecting portions;
• a second longitudinal portion located apart from the first longitudinal portion in a second direction intersecting the first direction and extending in the first direction, the second longitudinal portion having second intersecting portions arranged in the first direction, the welded portion intersecting itself at the second intersecting portions;
• and
• a plurality of connecting portions arranged in the first direction, each extending in the second direction and connecting the first longitudinal portion and the second longitudinal portion, wherein
• each of the first and second longitudinal portions includes a straight-line-like portion extending in the first direction, and each of the plurality of connecting portions includes a straight-line-like portion extending in the second direction, and
• the plurality of connecting portions form a grid-like structure in which each of an adjacent two of the plurality of connecting portions has a single intersection portion at which the straight-line-like portion of each of the adjacent two of the plurality of connecting portions intersect each other.