An integrated circuit chip includes multiple functional components and a central interconnect module. Preferably the coating fluid also contains a mordant, an aliphatic alcohol to assist dispersion of the hydrogel polymer and a particulate material to impart a porous structure to the coating. The reducing agent injector is provided on the outside of the bend of the bent portion to inject the reducing agent in a direction that deviates from a tangent line, which is tangent to a central axis line of the bent portion at a downstream-side end of the bent portion, toward the inside of the bend of the bent portion.