PURPOSE: To facilitate the quality control of the soldering part by connecting a bottom plate to frame-form body parts with bridges extending between the corners of the bottom plate, and arranging connecting tab parts to clearances between the side edges of the bottom plate and the side walls of the frame-form body parts.

CONSTITUTION: A central bottom plate 14' surrounded by frame-form body parts 10' is connected by connecting the frame-form body parts 10' with only four bridges 32 extending between the corners 33 of the bottom plate 14' integrally, while clearances 22' in which there is no bridge are formed between the bottom plate 14' and the frame-form body parts 10', and combining tab parts for soldering each contact are visibly arranged in the clearances 22'. As a result, since there is no bridge in the lines of connecting tab parts lined up in the clearances 22', the soldering pad lines can be recognized visually through the clearances 22', and furthermore, a fear of generating a solder bridge can be minimized. And even though a solder bridge is generated, it can be confirmed clearly from the upper side of the socket, and a soldering iron can be easily accessible to the clearances 22'.