configuration but have a smooth arcuate u shaped form as shown in fig6 still further the conductor strip 5 may be formed with two slits 6 as shown in fig7 in the illustrated example each of the two end portions of the strip 5 is formed with one slit 6 and connected to a substrate 2 or 2 u2032 fig8 a shows another possible configuration of the strip 5 in this embodiment the first terminal 5 a is formed with two rectangular cutouts spaced across a relatively narrow connecting portion 5 c with such an arrangement again the remaining or disappearing of the linear region 8 fig2 a is observed through the rectangular cutouts thus the quality inspection of the reflow soldering is readily performed in the illustrated example d 1 may be 3 0 mm d 2 may be 3 0 mm and d 3 may be 0 25 u02dc 0 75 mm if the above inspection is not required the strip 5 may be positioned so that the connecting portion 5 c projects from the edge of the substrate 2 entirely as shown in fig8 b or partially as shown in fig8 c the position of fig8 c is more advantageous to.