L1 is a maximum distance across a non-contacting section between intersection points of a straight line crossing the non-contacting section in parallel with an alignment direction of a carbon nanotubes in a plan view of a mounting section with a border between the non-contacting section and a contacting section. L2 is a maximum distance across the non-contacting section between intersection points of a straight line crossing the non-contacting section and intersecting the alignment direction of the carbon nanotubes in the plan view of the mounting section with the border between the non-contacting section and the contacting section. When L1 is larger than L2, at least L2 is more than 0 mm and less than 10 mm. When smaller, at least L1 is more than 0 mm and less than 10 mm. When equal, L1 and L2 are each more than 0 mm and less than 10 mm.