A memory card system may include a flexible integrated circuit device package, an upper flexible case, a lower flexible case, a wiring structure, an anisotropic conductive film, etc. The flexible integrated circuit device package may include a material capable of being bent or folded and a flexible integrated circuit device having a connection pad for an electrical connection. The upper flexible case may include a material capable of being bent or folded and may cover the integrated circuit device package. The lower flexible case may include a material capable of being bent or folded and the flexible integrated circuit device package may be fixed to the lower flexible case. The wiring structure may include a material capable of being bent or folded, and also may include a connection wiring disposed on an inner surface of the upper flexible case for electrically connecting the flexible integrated circuit device package with an external device, a connection pin disposed on an outer surface of the upper flexible
