A seat structure for a vehicle, such as a motorcycle, includes a seat arranged rearwardly of a fuel tank mounted on a vehicle body frame. The flexible spring members are biased toward one another by preloading material of the spring members. The top electrode containing titanium is placed on the diffusion barrier layer. A tree is in electrical contact with the bridge wherein the tree passes through a via of the substrate and is in electrical contact with a first trace of the second face.