Hereinafter, Examples 1 to 11 in which the structures of linking portions of the present invention are different from each other were produced. FIG. 9A shows basic structures of Examples 1 to 11, FIG. 9B shows a structure of a comparative example, and the total length thereof was 140 mm. Bent portions that correspond to any of the above-described aspects 1 to 5 were provided in the basic structures of Examples 1 to 11 shown in FIG. 9A, whereas no bent portion such as that in the examples was provided in the structure of the comparative example shown in FIG. 9B. The linking portions of these Examples 1 to 11 differ from each other in the width of the bent portions, the width of portions other than the bent portions (referred to as wire end portions hereinafter), the thickness of the bent portions, the length of the bent portions, the presence/absence of bypass heating wires, and the presence/absence of conductive portions. Also, vertex portions of the bent portions of Examples 1 to 11 and a comparative example had an acute angle (angle θ=45 degrees), and were not formed in an arc shape (the radius of curvature is 0). Also, all of the wire end portions had a thickness of 6 μm.

All of the linking portions according to Examples 1 to 11 and the comparative example were formed through silver printing on a square green glass having a thickness of 2 mm and 125 mm sides. Also, square and silver print application portions with 10 mm sides were provided at both ends of each linking portion.