JPH0320479B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a tin-lead alloy plating bath. Conventional technology and its problems Conventionally, tin-lead alloy plating bath (solder plating bath)
Nonionic surfactants such as polyoxyethylene nonyl phenyl ether, polyoxyethylene octylphenyl ether, and polyoxyethylene lauryl ether are used as brighteners, and if necessary, peptone, gelatin, etc. are used together. However, since brighteners made of such known nonionic surfactants have high foaming properties,
Not only does the bath itself foam during the plating operation, reducing workability, but the resulting plating film is dark gray and lacks density and surface smoothness. Means for Solving the Problems As a result of various studies in view of the problems of the prior art as described above, the inventor of the present invention has developed a method for adding a specific polyoxyalkylene bisphenol type surfactant to a tin-lead alloy. When added to a plating bath, it not only substantially eliminates or greatly reduces the factor of foaming that reduces workability, but also improves the stability of the plating bath and improves the properties of the plating film. I found out that it can be done. That is, the present invention provides a tin-lead alloy plating bath shown below. A tin-lead alloy plating bath characterized by containing 1 to 200 g of a polyoxyalkylene bisphenol type surfactant: and 1 to 200 g of a polyoxyalkylene bisphenol type surfactant, as well as quinoline derivatives and indole derivatives. and a tin-lead alloy plating bath characterized by containing 0.1 to 20 g/at least of at least one aromatic amine compound. The polyoxyalkylene bisphenol surfactant used in the present invention has the following general formula (1):
Contains the compound shown in General formula (1): {In the formula, each symbol means the following. X: CH ₂ CH ₂ O Y:

[Formula] R: hydrogen atom and C ₁ -C ₅ alkyl group n ₁ and n ₂ : number of 1 to 20, n ₁ = n ₂ may be satisfied. m ₁ and m ₂ : numbers from 0 to 10, m ₁ = m ₂ may be satisfied. Note that the positions of X and Y as repeating units can be changed arbitrarily, and both may exist randomly. } In the tin-lead alloy plating bath according to the present invention,
The above-mentioned polyoxyalkylene bisphenol type surfactant is blended in a proportion of 1 to 200 g/g. If the blending amount is less than 1g/, effects such as improving the stability of the plating bath and improving the leveling of the plating film will not be achieved sufficiently.On the other hand, if the blending amount exceeds 200g/, the plating bath As well as insufficient solubility in
Foaming properties are increased. In the present invention, the plated film is made more dense by further blending at least one of a quinoline derivative, an indole derivative, and an aromatic amine compound in addition to the above-mentioned polyoxyalkylene bisphenol type surfactant. be able to. Examples of quinoline derivatives include quinoline, isoquinoline, 8-hydroxyquinoline, 8-hydroxyquinoline-5-sulfonic acid, quinoline-2-sulfonic acid, quinoline-3-sulfonic acid, 2-methylquinoline, 2-methylquinoline-3- carboxylic acid, quinoline-2-carboxylic acid, quinoline-5,
Examples include 6-quinone, quinoline-5,8-quinone, quinoline-2,4-diol, and 4-oxyquinaldic acid. Indole derivatives include indole, 3-
Methylindole, 2,3-dimethylindole, 2,3,3-trimethylindole, 1-chloroindole, β-dimethylaminoindole, indole-3-aldehyde, 3-indole, 1-chloroindole, 3-bromoindole, Examples include 3-cyanoindole, 6-nitroindole-3-aldehyde, and 5-nitroindole-aldehyde. Aromatic amine compounds include aniline, o-
Toluidine, m-toluidine, p-toluidine,
o-nitroaniline, m-nitroaniline, p-
Nitroaniline, 2,3-dimethylaniline,
2,4-dimethylaniline, N,N-dimethylaniline, o-aminophenol, p-aminophenol, 2,4,6-trimethylaniline, 2,
5-dinitroaniline, 1,8-naphthalene diamine, 1,5-naphthalene diamine, α-naphthylamine, β-naphthylamine, sodium naphthionate, 1-naphthylamine-6-sulfonic acid, 1-naphthylamine-8-sulfonic acid, p −
Examples include nitrosodiphenylamine. The blending amount of at least one of the quinoline derivative, indole derivative and aromatic amine compound in the plating bath of the present invention is within the range of 0.1 to 20g/. When the amount of these compounds is less than 0.1g/, the improvement of the effect is not sufficient; on the other hand, when the amount of these compounds is less than 0.1g/
If it exceeds 20%, it becomes difficult to completely dissolve in the plating bath, which is economically disadvantageous. The components other than the above additives in the tin-lead plating bath of the present invention are the same as those in known plating baths. That is, the plating bath of the present invention can be obtained by blending the above-mentioned additives in a stable ratio into a known tin borofusate-lead plating bath, organic acid tin-lead plating bath, or the like. Effects of the Invention When plating is performed using the tin-lead plating bath according to the present invention, stable operation is possible in a wider current density range than before, and a uniform white plating film can be obtained. I can do it. Moreover, the obtained tampered film is extremely dense and exhibits good solderability. Examples Examples and comparative examples are shown below to further clarify the features of the present invention. Note that the condition of the plating film in Examples and Comparative Examples was observed by Hull cell test. In the Hull cell test, the bath temperature was 25℃ and the current was 1A.
Plating for 5 minutes or at a current of 0.5A,
The range of current density at which a uniform white film was obtained and the density of the film obtained at that time were compared. Example 1 Plating was carried out using a tin-lead plating bath having the composition shown below, and the characteristics of the resulting matted film were investigated. 45% stannous borofluoride 100 g / 45% leadous borofluoride 40 g / 42% hydroborofluoric acid 300 g / Additive of the present invention {In general formula (1), R = methyl,
Additive of 10 moles of ethylene oxide} 40 g/ The plating film was white, and scanning electron micrographs (6400x magnification) confirmed that it was uniform and dense. Example 2 Plating was carried out using a tin-lead plating bath having the composition shown below. 45% stannous borofluoride 120 g / 45% leadous borofluoride 60 g / 42% hydroborofluoric acid 300 g / boric acid 10 g / Additive of the present invention {In general formula (1), R = methyl,
12 moles of ethylene oxide, 1 mole of propylene oxide adduct} 20g/2-methyl-8-hydroxyquinoline
By blending 0.5 g/2-methyl-8-hydroxyquinoline, a uniform and dense white plating film could be obtained over a wider current density range than in Example 1. Comparative Example 1 Plating was carried out using a known tin-lead plating bath having the composition shown below, and the properties of the resulting matted film were investigated. 45% stannous borofluoride 100g/ 45% leadous borofluoride 40g/ 42% hydroborofluoric acid 300g/ polyoxyethylene nonyl phenyl ether (10 moles of ethylene oxide adduct) 40g/ The resulting sticky film is The entire surface was dark black, and black spongy deposits were observed in the high current density areas. Furthermore, scanning electron micrographs (6400x magnification) revealed that the denseness of the plating film was inferior to that of Examples 1 and 2. Comparative Example 2 Plating was carried out using a known tin-lead plating bath having the composition shown below, and the properties of the resulting matted film were investigated. 45% stannous borofluoride 120g/ 45% leadous borofluoride 50g/ 42% hydroborofluoric acid 240g/ polyoxyethylene octyl phenyl ether (15 mole ethylene oxide adduct) 40g/ peptone 5g/ Obtained weight As in Comparative Example 1, the entire film was dark black, and black spongy deposits were observed in the high current density areas. Furthermore, scanning electron micrographs (6400x magnification) confirmed that the density of the plating film was still inferior to that of Examples 1 and 2. Examples 3 to 14 Plating was carried out using the tin-lead plating baths of the present invention shown below. Example 3 Tin phenolsulfonate 20g/Lead phenolsulfonate 10g/Phenolsulfonic acid 70g/Additive of the present invention {In general formula (1), R=methyl,
20 mole adduct of ethylene oxide} 20g/ 8-hydroxyquinoline 5g/ Example 4 45% stannous borofluoride 120g/ 45% leadous borofluoride 60g/ 42% hydroborofluoric acid 300g/ Additive of the present invention {general In formula (1), R=ethyl,
20 moles of ethylene oxide, 2 moles of propylene oxide adduct} 20 g / 2-methylquinoline 1 g / Example 5 45% stannous borofluoride 160 g / 45% leadous borofluoride 80 g / 42% hydroborofluoric acid 240 g / bottle Inventive additive {In general formula (1), R = hydrogen, but 10 moles of ethylene oxide and 4 moles of propylene oxide are randomly added}
50g/ Quinoline-5,6-quinone 0.1g/ Example 6 Stannous acetate 30g/ Leadous acetate 10g/ Citric acid 70g/ Additive of the present invention {In general formula (1), R = hydrogen, ethylene oxide 12 Molar adduct} 20g/ 3-methylindole 2g/ Example 7 45% stannous borofluoride 60g/ 45% leadous borofluoride 30g/ 42% hydroborofluoric acid 200g/ Additive of the present invention {General formula (1) ), R=methyl,
However, 12 moles of ethylene oxide and 4 moles of propylene oxide are added in the form of blocks.
20g / Indole 1g / Example 8 Stannous chloride 40g / Nitrate 10g / Sodium gluconate 100g / Additive of the present invention {In general formula (1), R = methyl,
15 moles of ethylene oxide, 3 moles of propylene oxide adduct} 20g/β-dimethylaminomethylindole 0.2g/Example 9 Tin methanesulfonate 30g/Lead methanesulfonate 10g/Methanesulfonic acid 100g/Additive of the present invention {General formula In (1), R=methyl,
Ethylene oxide 15 adduct} 20g/ 2,4-dimethylaniline 1g/ 8-hydroxyquinoline 0.5g/ Example 10 45% stannous borofluoride 30g/ 45% leadous borofluoride 10g/ 42% hydrogen borofluoride Acid 100g/ Additive of the present invention {in general formula (1), R = hydrogen, 12 moles of ethylene oxide, 5 moles of propylene oxide adduct} 20g/ Example 11 Stannous acetate 60g/ Leadous acetate 20g/ Gluconic acid Sodium 150g/Additive of the present invention {In general formula (1), R=methyl,
10 moles of ethylene oxide adduct} 20 g / β-naphthylamine 2 g / Example 12 45% stannous borofluoride 120 g / 45% leadous borofluoride 60 g / 42% hydroborofluoric acid 350 g / Additive of the present invention {General formula In (1), R=methyl,
10 moles of ethylene oxide adduct} 20g/ 1,8-naphthalene diamine 1g/ Example 13 Tin phenolsulfonate 100g/ Lead phenolsulfonate 40g/ Phenolsulfonic acid 200g/ Additive of the present invention {In general formula (1), R = methyl,
However, 15 moles of ethylene oxide and 5 moles of propylene oxide are randomly added.
15g/ Sodium naphthionate 0.5g/ Example 14 45% stannous borofluoride 100g/ 45% leadous borofluoride 40g/ 42% hydroborofluoric acid 200g/ Additive of the present invention {In general formula (1), R = methyl,
17.5 moles of ethylene oxide adduct} 20 g / 1 g of quinoline / 0.5 g of 1-naphthylamine-8-sulfonic acid / When plating was performed using each of the plating baths of Examples 3 to 14 above, a wide current density range was obtained. A uniform white plating film was obtained. All of these films were dense and showed good solderability. Example 15 Using a tin-lead plating bath with the composition shown below,
The foaming and defoaming properties of the bath were investigated. First, as a foaming test, an air stone was placed in a graduated cylinder containing plating solution.
Air was pumped in, and the foaming height (mm) was measured 30 seconds later. The air supply capacity of the pump used was approximately 650 ml per 30 seconds. In addition, as a defoaming test, the height (mm) of foaming was measured 30 seconds, 1 minute, 2 minutes, and 3 minutes after the above-mentioned pump stopped sending air. The results are shown in Table 1. 45% stannous borofluoride 90 g / 45% leadous borofluoride 10 g / 42% hydroborofluoric acid 240 g / Additive of the present invention {In general formula (1), R = methyl,
10 moles of ethylene oxide adduct} 50 g / 8-hydroxyquinoline 2 g / Comparative Example 3 Using a tin-lead plating bath with the composition shown below,
In the same manner as in Example 15, the foaming and defoaming properties of the bath were examined. The results are also shown in Table 1. 45% stannous borofluoride 90g/ 45% leadous borofluoride 10g/ 42% hydroborofluoric acid 240g/ polyoxyethylene nonyl phenyl ether (10 moles of ethylene oxide adduct) 50g/ peptone 5g/

[Table] From the results shown in Table 1, the plating bath according to the present invention has a foaming property that is approximately half that of the known plating bath. It also has excellent antifoaming properties.

Claims (1)

[Scope of Claims] 1. A tin-lead alloy plating bath characterized by containing 1 to 200 g of a polyoxyalkylene bisphenol type surfactant. 2 1 to 200 g of polyoxyalkylene bisphenol type surfactant and quinoline derivative,
A tin-lead alloy plating bath characterized by containing 0.1 to 20 g/at least one of an indole derivative and an aromatic amine compound.