Bonded part, manufacturing method of bonded part, ink tank, and ink cartridge

An ink tank comprising:

• a bonded part including:
• a first part;
• and
• a second part;
• wherein the first part includes a wall portion and a space portion surrounded by the wall portion,
• wherein a first shape portion formed of bonding resin is arranged at a position between the second part and the wall portion, and
• wherein the first shape portion includes a convex portion that passes through an internal portion of the second part and penetrates to an opposite side of the first part.

An ink cartridge comprising:

• a bonded part including:
• a first part;
• and
• a second part,
• wherein the first part includes a wall portion and a space portion surrounded by the wall portion,
• wherein a first shape portion formed of bonding resin is arranged at a position between the second part and the wall portion, and
• wherein the first shape portion includes a convex portion that passes through an internal portion of the second part and penetrates to an opposite side of the first part.