Providing a corrosion-resistant terminal material by using a copper or copper alloy base material as a terminal to which an end of wire having an aluminum core wire is crimped. Corrosion-resistant terminal material has a substrate made of copper or a copper alloy and a film layered on the substrate, the corrosion-terminal material is formed to have a planned core wire contact part with which a core wire of an electric wire is in contact when the material is formed to a terminal and a planned contact part to be a contact part: the film formed in the planned core wire contact part has a tin layer made of tin or tin alloy and a metallic zinc layer formed on the tin layer; the film formed in the planned contact part has a tin layer made of tin or tin alloy but does not have a metallic zinc layer.

A tin alloy plating solution comprising a soluble tin salt, a soluble salt of a metal nobler than tin, and a sulfide compound represented by general formula (I). In formula (I), n is 1 to 3. The metal nobler than tin is preferably silver, copper, gold, or bismuth.

A terminal material for a connector terminal, using a copper or copper alloy substrate is crimped to an end of wire formed from an aluminum wire material; and a terminal using this terminal material: a zinc layer 4 that is formed of zinc or a zinc alloy and a tin layer 5 that is formed of tin or a tin alloy are sequentially laminated in this order on a substrate 2 that is formed of copper or a copper alloy: with respect to the zinc layer and the tin layer, the adhesion amount of tin contained in the whole layers is from 0.5 mg/cm.sup.2 to 7.0 mg/cm.sup.2 (inclusive) and the adhesion amount of zinc contained in the whole layers is from 0.07 mg/cm.sup.2 to 2.0 mg/cm.sup.2 (inclusive), and the content percentage of zinc in the vicinity of the surface is from 0.2% by mass to 10.0% by mass (inclusive).

An electrodeposit formed by using a tin or tin alloy plating bath containing a prescribed branched polyoxyalkylene compound, such as an alkylene oxide adduct of aliphatic monoamine or polyamine in which a plurality of oxyalkylene chains are bonded to a nitrogen atom of an amine structure in a molecule, or an alkylene oxide adduct of glycerin or polyglycerin in which oxyalkylene chains are respectively bonded to a plurality of oxygen atoms of an alcohol structure in a molecule, suppresses formation defect such as abnormal growth of the electrodeposit. The electrodeposit also improves yield from the viewpoint of quality control.

An electrodeposit formed by using a tin or tin alloy plating bath containing a prescribed branched polyoxyalkylene compound, such as an alkylene oxide adduct of aliphatic monoamine or polyamine in which a plurality of oxyalkylene chains are bonded to a nitrogen atom of an amine structure in a molecule, or an alkylene oxide adduct of glycerin or polyglycerin in which oxyalkylene chains are respectively bonded to a plurality of oxygen atoms of an alcohol structure in a molecule, suppresses formation defect such as abnormal growth of the electrodeposit. The electrodeposit also improves yield from the viewpoint of quality control.

An ionically resistive ionically permeable element for use in an electroplating apparatus includes ribs to tailor hydrodynamic environment proximate a substrate during electroplating. In one implementation, the ionically resistive ionically permeable element includes a channeled portion that is at least coextensive with a plating face of the substrate, and a plurality of ribs extending from the substrate-facing surface of the channeled portion towards the substrate. Ribs include a first plurality of ribs of full maximum height and a second plurality of ribs of smaller maximum height than the full maximum height. In one implementation the ribs of smaller maximum height are disposed such that the maximum height of the ribs gradually increases in a direction from one edge of the element to the center of the element.

An ionically resistive ionically permeable element for use in an electroplating apparatus includes ribs to tailor hydrodynamic environment proximate a substrate during electroplating. In one implementation, the ionically resistive ionically permeable element includes a channeled portion that is at least coextensive with a plating face of the substrate, and a plurality of ribs extending from the substrate-facing surface of the channeled portion towards the substrate. Ribs include a first plurality of ribs of full maximum height and a second plurality of ribs of smaller maximum height than the full maximum height. In one implementation the ribs of smaller maximum height are disposed such that the maximum height of the ribs gradually increases in a direction from one edge of the element to the center of the element.

Providing a copper alloy plate, in which center Mg concentration at a center part in a plate thickness direction 0.1 mass % or more and less than 0.3 mass %, center P concentration is 0.001 mass % or more and 0.2 mass % or less, and the balance is composed of Cu and inevitable impurities; in which surface Mg concentration at a surface is 70% or less of the center Mg concentration; in which a surface layer part defined by a prescribed thickness from the surface has a concentration gradient of Mg of 0.05 mass %/m or more and 5 mass %/m or less increasing from surface toward center part of the plate thickness direction; and in which restraint of color change of the surface and increase of electrical contact resistance, and adhesiveness of a plating film are excellent due to maximum Mg concentration in the surface layer part is 90% of the center Mg concentration.

An aqueous composition including (a) metal ions including tin ions and silver ions and (b) at least one complexing agent of formula C11

R.sup.C12-X.sup.C11-R.sup.C11 (C11)

and their salts, where X.sup.C11 is selected from (a) a divalent 5 or 6 membered aromatic N-heterocyclic group; (b) a divalent 6 membered aromatic carbocyclic group; and (c) a divalent 5 or 6 membered aliphatic N-heterocyclic group including one N atom and optionally a second heteroatom selected from N and O; all of which may be unsubstituted or substituted by one or more OH or one or more R.sup.C14; R.sup.C11 is selected from

##STR00001## ; and R.sup.C12 is selected from R.sup.C11, X.sup.C11-R.sup.C11, H, OH, NR.sup.C14.sub.2, C.sub.1 to C.sub.10 alkyl, and C.sub.1 to C.sub.10 alkoxy

A tin alloy plating solution of the present invention includes (A) a soluble salt or oxide including at least a stannous salt, (B) a soluble salt of a metal nobler than tin, (C) a tin complexing agent formed of a sugar alcohol having 4 or more and 6 or less carbon atoms, (D) a free acid, and (E) an antioxidant. In addition, a content of the tin complexing agent is 0.1 g/L or more and 5 g/L or less, and a concentration of divalent tin ions (Sn.sup.2+) is 30 g/L or more.