Patent ID: 6998036

Claim:
An acidic, aqueous electrolyte for depositing tin-silver alloys comprising at least one of alkylsulfonic acids and alkanolsulfonic acids, at least one soluble tin (II) salt, at least one soluble silver (I) salt, and at least one organic sulfur compound, wherein the at least one organic sulfur compound has the following general formula: X—R 1 —[Z—R 2 ] n —Z—R 3 —Y (I) wherein n=1 to 20, X and Y each independently represent —OH, —SH, or —H, Z is a sulfur atom or an oxygen atom and the chemical groups Z are the same or different R 1 , R 2 and R 3 each independently represent an optionally substituted linear or branched alkylene group having at least 2 carbon atoms, and the chemical groups R 2 are the same or different, and if only one Z represents a sulfur atom, X and/or Y represent —SH, and if Z is exclusively an oxygen atom, X and Y are both —SH.