Abstract: A Pb-free Sn-based material part of a wiring conductor is provided at least at a part of its surface, and the Sn-based material part includes a base metal doped with an oxidation control element. The oxidation control element is at least one element selected from a group consisted of P, Ge, K, Zn, Cr, Mn, Na, V, Si, Ti, Al, Li, Mg and Ca. The wiring conductor is reflow processed, such that at least one of the Sn and the oxidation control element is diffused to form an alloy.

Abstract: A fluororesin heated at a temperature at or above the melting point of the resin is exposed in an inert gas atmosphere having an oxygen concentration of not more than 10 Torr to an ionizing radiation at a radiation dose of 0.1 kGy to 10 MGy to prepare a crosslinked fluororesin. The crosslinked fluororesin is exposed to an ionizing radiation at a radiation dose of 10 kGy to 5 MGy, and is then brought into contact with a functional group-containing organic compound to cause a graft reaction. By virtue of this constitution, a modified fluororesin is provided which has satisfactory mechanical strength and, at the same time, has, imparted thereto, for example, ion-exchange capacity, hydrophilicity, adhesive property, or abrasion resistance.

Abstract: A fluororesin heated at a temperature at or above the melting point of the resin is exposed in an inert gas atmosphere having an oxygen concentration of not more than 10 Torr to an ionizing radiation at a radiation dose of 0.1 kGy to 10 MGy to prepare a crosslinked fluororesin. The crosslinked fluororesin is exposed to an ionizing radiation at a radiation dose of 10 kGy to 5 MGy, and is then brought into contact with a functional group-containing organic compound to cause a graft reaction. By virtue of this constitution, a modified fluororesin is provided which has satisfactory mechanical strength and, at the same time, has, imparted thereto, for example, ion-exchange capacity, hydrophilicity, adhesive property, or abrasion resistance.