This tin or tin alloy electroplating solution according to one aspect contains a soluble salt (A) including at least a stannous salt, one or more compounds (B) selected from the group consisting of an organic acid, an inorganic acid, and a salt thereof, a surfactant (C) that is a polyoxyethylene polycyclic phenyl ether sulfuric acid ester salt represented by the following General Formula (1), and a leveling agent (D).

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In General Formula (1), m is an integer of 1 to 3, n is an integer of 10 to 30, and X is a cation.

A method for manufacturing a laminated tinplate for packaging applications, the laminated tinplate including a tinplate sheet and a thermoplastic laminate layer that covers at least one side of the tinplate steel sheet, to a laminated tinplate produced thereby and use thereof in a process to produce containers for packaging purposes.

A method for passivating a tinplate strip after electrodepositing the tin layer or tin layers, or after an optional flow-melting of the electrodeposited tin layer or tin layers, and an apparatus for producing the passivated tinplate strip.

The present invention provides a method of tin-plating a copper alloy for electric or electronic parts and automobile parts which has excellent insertion force, heat-resistant peeling, and solderability, and a tin-plating material of a copper alloy manufactured therefrom.

In a terminal material with a silver coating film including a silver layer on a surface, a terminal and a terminal material having high reliability are easily manufactured with low cost without a heat treatment. A base material formed of copper or a copper alloy; and nickel layer, an intermediate layer, and a silver layer laminated on the base material in this order are included, the nickel layer has a thickness of 0.05 μm to 5.00 μm and is formed of nickel or a nickel alloy, the intermediate layer has a thickness of 0.02 μm to 1.00 μm and is an alloy layer containing silver (Ag) and a substance X, and the substance X includes one or more kinds of tin, bismuth, gallium, indium, and germanium.

External electrical connectors and methods of forming such external electrical connectors are discussed. A method includes forming an external electrical connector structure on a substrate. The forming the external electrical connector structure includes plating a pillar on the substrate at a first agitation level affected at the substrate in a first solution. The method further includes plating solder on the external electrical connector structure at a second agitation level affected at the substrate in a second solution. The second agitation level affected at the substrate is greater than the first agitation level affected at the substrate. The plating the solder further forms a shell on a sidewall of the external electrical connector structure.

A pin terminal includes a bar-like base material and a plating layer covering a predetermined region of the base material. A constituent material of the base material is pure copper or a copper alloy. The plating layer includes a tin-based layer made of metal containing tin. One end side of the base material includes a tip covering portion covering an entire region in a circumferential direction of the base material. The tin-based layer includes the tip covering portion. The tip covering portion includes a thin film portion and a thick film portion at positions different in the circumferential direction of the base material. The thin film portion is provided in contact with the base material. The number of whiskers present on a surface of the thin film portion is 15 or less in a square visual field having one side length of 0.35 mm.

To provide a Sn-based plated steel sheet excellent in yellowing resistance, coating film adhesiveness, and sulfurization blackening resistance without performing the conventional chromate treatment.

A Sn-based plated steel sheet of the present invention includes: a steel sheet; a Sn-based plating layer located on at least one surface of the steel sheet; and a coating layer located on the Sn-based plating layer, wherein: the Sn-based plating layer contains 0.10 to 15.00 g/m.sup.2 of Sn per side in terms of metal Sn; the coating layer contains a Zr oxide and a Mn oxide; a content of the Zr oxide is 0.20 to 50.00 mg/m.sup.2 per side in terms of metal Zr; a content of the Mn oxide in terms of metal Mn is 0.01 to 0.50 times on a mass basis relative to the content of the Zr oxide in terms of metal Zr; and a depth position A where an element concentration of Mn is maximum is located on a side closer to a surface of the coating layer than a depth position B where an element concentration of Zr is maximum, and a distance in a depth direction between the depth position A and the depth position B is 2 nm or more in an element analysis in the depth direction by XPS.

A terminal material having a base material in which at least a surface is made of Cu or Cu alloy; an Ni layer with at thickness of 0.1 μm to 1.0 μm inclusive on the base material; a Cu—Sn intermetallic compound layer with a thickness of 0.2 μm to 2.5 μm inclusive on the Ni layer; and an Sn layer with a thickness of 0.5 μm to 3.0 μm inclusive on the Cu—Sn intermetallic compound layer, when cross sections of the Cu—Sn intermetallic compound layer and the Sn layer are analyzed by the EBSD method with a measuring step 0.1 μm and a boundary in which misorientation between adjacent pixels is 2° or more is deemed to be a crystal boundary, an average crystal grain size Dc of the Cu—Sn intermetallic compound layer is 0.5 μm or more, and a grain size ratio Ds/Dc is five or less.

A tin-plated copper terminal material in which on a substrate made of copper or copper alloy, a nickel-or-nickel-alloy layer, a copper-tin alloy layer, and a tin layer are laminated in this order; in this material, the tin layer has an average thickness 0.2 μm to 1.2 μm inclusive; the copper-tin alloy layer is a compound alloy layer in which Cu.sub.6Sn.sub.5 is a main ingredient and part of copper in the Cu.sub.6Sn.sub.5 is substituted with nickel, and an average crystal grain size is 0.2 μm to 1.5 μm inclusive; part of the copper-tin alloy layer appears on a surface of the tin layer and tin solidification parts exist like islands; and the tin solidification parts have an average diameter 10 μm to 1000 μm inclusive in a direction along the surface of the tin layer and an area ratio to the surface of the tin layer 1% to 90% inclusive.