BRIEF DESCRIPTION OF THE DRAWINGS [0028]FIGS. 1A, 1B, 1C and 1D are schematic cross sectional views showing examples of a curved resilient contact piece in a front portion of a lead formed on a substrate, the resilient contact piece extending over the edge of the substrate. [0029]FIGS. 2A, 2B and 2C are a plan view and cross sectional views showing examples of a resilient contact piece extending o