A board terminal 1 includes a base material 11 made of a metal material and a plating film 12 covering a surface of the base material 11. The plating film 12 includes an outermost layer 120 having a Sn mother phase 120a and SnPd-based alloy phases 120b dispersed in the Sn mother phase 120a, the Sn mother phase 120a and the SnPd-based alloy phases 120b being present on an outer surface. A Pd content in the outermost layer 120 is not more than 7 atomic %. A board connector 2 includes the board terminal 1 and a housing 20 for holding the board terminal 1.

In some examples, an article including a substrate and a multi-layered coating on at least a portion of the substrate. The multi-layered coating including at least one nano-crystalline layer comprising a metal or a metal alloy and a corrosion resistant layer on the at least one nano-crystalline layer. The nano-crystalline layer defining an average grain size of less than 50 nanometers (nm) and the corrosion resistant layer including at least one of nickel metal, tin metal, zinc metal, cadmium metal, chromium metal, nickel-phosphorus alloy, nickel-sulfur alloy, nickel-boron alloy, nickel-cadmium alloy, nickel-zinc alloy, and tin-zinc alloy.

A copper alloy sheet with a Sn coating layer comprises a base material made of CuNiSi system copper alloy. Formed on the base material is a Ni coating layer having an average thickness of 0.1 to 0.8 m. Formed on the Ni coating layer is a CuSn alloy coating layer having an average thickness of 0.4 to 1.0 m. Formed on the CuSn alloy coating layer is an Sn coating layer having average thickness of 0.1 to 0.8 m. A material surface is subject to reflow treatment and has arithmetic mean roughness Ra of 0.03 m or more and less than 0.15 m in both a direction parallel to the rolling direction and a direction perpendicular to the rolling direction. An exposure rate of the CuSn alloy coating layer to the material surface is 10 to 50%. A fitting type connection terminal requiring low insertion force can be obtained at a low cost.

An electric contact for preventing a terminal of an electric part and the electric contact from sticking to each other after a continuity test to improve the durability of the electric contact; and a socket for electric parts using the electric contact. The electric contact of this invention includes a first layer made from a material into which Sn melts and diffuses upon application of heat; and a second layer formed on the outer side of the first layer and made from a material lower in the rate at which Sn melts and diffuses upon application of heat than the first layer.

A steel sheet for a container includes a steel sheet, a Sn coated layer which is provided as an upper layer of the steel sheet and contains Sn in an amount of 560 to 5600 mg/m.sup.2 in terms of Sn metal, and a chemical treatment layer which is provided as an upper layer of the Sn coated layer and contains a Zr compound in an amount of 3.0 to 30.0 mg/m.sup.2 in terms of Zr metal and a Mg compound in an amount of 0.50 to 5.00 mg/m.sup.2 in terms of Mg metal.

The present invention accurately distinguishes a soldering material less likely to oxidize. A Cu core ball has a Cu ball having a predetermined size, and a solder layer coating the Cu ball. The Cu ball provides a space between a semiconductor package and a printed circuit board. The Cu core ball has the soldering material having lightness greater than or equal to 62.5 in L*a*b* color space subsequent to a heating storage test performed for 72 hours in a temperature-controlled bath at 150 C. with a temperature of 25 C. and 40% humidity, and the soldering material, prior to the heating storage test, having lightness greater than or equal to 65 in the L*a*b* color space and yellowness less than or equal to 7.0 in the L*a*b* color space.

Provide is a metal-coated liquid-crystal polymer film that is suitable for microcircuit processing and capable of reducing the transmission loss of circuits. The metal-coated liquid-crystal polymer film comprising: a polymer film comprising a polymer film main body capable of forming an optically anisotropic melt phase; a first metal layer layered on at least one side of the polymer film main body; and a second metal layer layered on the first metal layer, wherein in an analysis of oxygen concentration in a thickness direction using XPS, the average oxygen concentration of the first metal layer is 2.5 atom % or less.

A tin-plated copper alloy terminal material in which an Sn-based surface layer is formed on a surface of a base material that is made of copper or a copper alloy, and a CuSn alloy layer and an Ni layer or an Ni alloy layer are sequentially formed between the Sn-based surface layer and the base material from the Sn-based surface layer side: the CuSn alloy layer is a layer that is formed only of an intermetallic compound alloy which is obtained by substituting some of Cu in Cu.sub.6Sn.sub.5 alloy with Ni; and parts of the CuSn alloy layer are exposed from the Sn-based surface layer, thereby forming a plurality of exposed portions; an average thickness of the Sn-based surface layer is from 0.2 m to 0.6 m (inclusive); and an area rate of the exposed portions of the CuSn alloy layer relative to a surface area of is 1% to 40% (inclusive).

A method of electroless gold plating includes a step of forming an underlying alloy layer on a base material and a step of forming a gold plate layer directly on the underlying alloy layer by electroless reduction plating using a cyanide-free gold plating bath. The underlying alloy layer is formed of an M1-M2-M3 alloy, where M1 is at least one element selected from Ni, Fe, Co, Cu, Zn, where Sn, M2 is at least one element selected from Pd, Re, Pt, Rh, Ag and where Ru, and M3 is at least one element selected from P and B.

In various embodiments, electronic devices such as touch-panel displays incorporate interconnects featuring a conductor layer and, disposed above the conductor layer, a capping layer comprising an alloy of Cu and one or more refractory metal elements selected from the group consisting of Ta, Nb, Mo, W, Zr, Hf, Re, Os, Ru, Rh, Ti, V, Cr, and Ni.