Patent ID: 7628616

Claim:
A connecting unit for establishing a connection with a plurality of external connecting portions of an electronic device, the connecting unit comprising a base; and a plurality of spiral contactors formed on the base and having a spiral shape, the spiral contactors being put in contact with the external connecting portions of the electronic device, wherein each of the spiral contactors comprises: a conductive layer for transmitting an electrical signal, the cross section of an outer shape of the conductive layer being a quadrangle; and an auxiliary resilient layer formed on a surface of the conductive layer, the auxiliary resilient layer covering the surface of the conductive layer such that the conductive layer is completely surrounded by the auxiliary resilient layer in a cross section, the cross section of an outer shape of the auxiliary resilient layer being a quadrangle, wherein the conductive layer is a single layer having a specific resistance lower than a specific resistance of the auxiliary resilient layer and being composed of copper or a copper alloy; and the auxiliary resilient layer comprises a Ni—P alloy having a yield point and an elastic modulus higher than a yield point and an elastic modulus of the conductive layer, the auxiliary resilient layer having a thickness to provide desired resilient properties to the spiral contactors, and wherein the auxiliary resilient layer comprises Ni 100−x P x , where 10≦x≦30 by atomic percent, and contains an amorphous phase.