Electrolytic tin plating solution

Abstract

An electrolytic tin plating solution contains a compound serving as a source of supply of tin ions and an unsaturated aldehyde compound having a heterocyclic group.

What is claimed is: 
     
         1 . An electrolytic tin plating solution comprising:
 a compound serving as a source of supply of tin ions; and   an unsaturated aldehyde compound having a heterocyclic group.   
     
     
         2 . The electrolytic tin plating solution of  claim 1 , wherein
 the heterocyclic group is a five- or six-membered heterocyclic group containing at least one of an oxygen atom, a nitrogen atom, or a sulfur atom.   
     
     
         3 . The electrolytic tin plating solution of  claim 1 , wherein
 a content of the unsaturated aldehyde compound having the heterocyclic group in the electrolytic tin plating solution is from 0.01 mmol/L to 10 mmol/L.   
     
     
         4 . The electrolytic tin plating solution of  claim 1 , wherein
 grains to be deposited have a maximum grain size of 10 um or smaller.   
     
     
         5 . The electrolytic tin plating solution of  claim 1 , wherein
 the heterocyclic group is one, two, or more groups selected from a pyrrolidine group, a pyrrole group, a tetrahydrofuran group, an oxolane group, a furan group, a tetrahydrothiophene group, a thiolane group, a thiophene group, an imidazole group, a pyrazole group, an imidazoline group, an oxazole group, a thiazole group, a thiazolidine group, a triazole group, a tetrazole group, a dioxolane group, an oxadiazole group, a thiadiazole group, a piperidine group, an azinane group, a tetrahydropyran group, an oxane group, a tetrahydrothiopyran group, a pyridine group, a pyrane group, a thiopyran group, a pyrimidine group, a pyrazine group, a pyridazine group, a thiazine group, a morpholine group, a dioxane group, a dithiin group, a thiomorpholine group, a trithiane group, a dithiazine group, a thiazepine group, an indole group, an isoindole group, an indolizine group, a benzimidazole group, a benzotriazole group, a purine group, a quinoline group, an isoquinoline group, a quinazoline group, a quinoxaline group, a cinnoline group, a phthalazine group, a chromene group, an isochromene group, a benzodioxole group, a benzodioxan group, a benzoxazole group, a benzothiazole group, a pteridine group, a phenothiazine group, a phenanthridine group, and a thianthrene group.   
     
     
         6 . The electrolytic tin plating solution of  claim 1 , wherein
 the unsaturated aldehyde compound having the heterocyclic group is one, two, or more selected from 3 -(2-furyl)acrolein, 2-methyl-3-(2-furyl)propenal, 3-(5-nitro-2-furyl)acrolein, (4-pyridyl)acrolein, 1,3-benzodioxole-5-acrolein, 3-[3-(4-fluorophenyl)-1-isopropylindol-2-yl]acrolein, 5-hydroxytetrahydrofuran-2-acrolein, 5-(2-furyl)-2,4-pentadienal, 2-formyl-3-(2-furyl)propenenitrile, 2-cyano-3-(2-furyl)propenal, 3-(4-pyridyl)propenal, pyridine-3-propenal, 3-(1H-indole-3-yl)propenal, 3-(3,4-diethyl-2-pyrrolyl)propenal, 3-(2-thienyl)acrolein, and 3-(isoindoline-2-yl)propenal.