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.

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.

The present disclosure provides an electroplating method, comprising providing an electroplating solution, wherein the electroplating solution includes an effective microorganisms aqueous solution and metal chloride; disposing a workpiece, wherein at least a part of the workpiece is in contact with the electroplating solution; and performing an electroplating process to electroplate metal of the metal chloride onto the workpiece.

The present disclosure provides an electroplating method, comprising providing an electroplating solution, wherein the electroplating solution includes an effective microorganisms aqueous solution and metal chloride; disposing a workpiece, wherein at least a part of the workpiece is in contact with the electroplating solution; and performing an electroplating process to electroplate metal of the metal chloride onto the workpiece.

The present invention provides a high-concentration tin sulfonate aqueous solution, in which a divalent tin ion (Sn.sup.2+) concentration is 360 g/L to 420 g/L, a tetravalent tin ion (Sn.sup.4+) concentration is 10 g/L or less, a free methanesulfonic acid concentration is 40 g/L or less, a Hazen unit color number (APHA) is 240 or less, and a turbidity is 25 FTU or less. This aqueous solution is produced such that stannous oxide powder whose temperature is adjusted to a temperature of 10° C. or lower is added to an aqueous methanesulfonic acid solution having a concentration of 60% by mass to 90% by mass when the aqueous solution circulates in a state of being maintained at the temperature of 10° C. or lower, and the stannous oxide powder is dissolved.

The present invention relates to the use of an aqueous composition comprising tin ions optionally further alloy metal ions selected from silver, copper, indium, and bismuth ions and at least one additive comprising a linear or branched polyimidazolium compound comprising the structural unit of formula (L1) for depositing tin or tin alloy containing layers and a process for depositing tin alloy layer onto a substrate. ##STR00001##

The present invention relates to the use of an aqueous composition comprising tin ions optionally further alloy metal ions selected from silver, copper, indium, and bismuth ions and at least one additive comprising a linear or branched polyimidazolium compound comprising the structural unit of formula (L1) for depositing tin or tin alloy containing layers and a process for depositing tin alloy layer onto a substrate. ##STR00001##

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.

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.

The present invention concerns a metal or metal alloy deposition composition, particularly a copper or copper alloy deposition composition, for electrolytic deposition of a metal or metal alloy layer, particularly for electrolytic deposition of a copper or copper alloy layer, comprising at least one type of metal ions to be deposited, preferably copper ions, and at least one imidazole based plating compound. The present invention further concerns a method for preparation of the plating compound, the plating compound itself and its use in a metal or metal alloy deposition composition. The inventive metal or metal alloy deposition composition can be preferably used for filling recessed structures, in particular those having higher diameter to depth aspect ratios.