JPH01242795A - Tin-lead alloy plating bath - Google Patents

Abstract

PURPOSE:To stably form a uniform white plating film in a wide current density range by adding a specified amt. of a polyoxyalkylene bisphenol type surfactant to an Sn-Pb alloy plating bath. CONSTITUTION:A polyoxyalkylene bisphenol type surfactant is added to an Sn-Pb alloy plating bath by 1-200g/l and at least one among a quinoline deriv., an indole deriv. and an arom. amine compd. is further added by 0.1-20g/l as required. By using the plating bath, stable plating can be carried out in a wide current density range and a uniform white plating film can be obtd. This obtd. plating film is very dense and has satisfactory solderability.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a tin-lead alloy plating bath.

Conventional technology and its problems Conventionally, in tin-lead alloy plating baths (solder plating baths), nonionic interfaces such as polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene lauryl ether, etc. have been used as brighteners. An activator is used, and if necessary, peptone, gelatin, etc. are also used in combination.

However, since brighteners made of known nonionic surfactants have high foaming properties, the bath itself foams during plating operations, reducing workability, and the resulting plating film has a dark gray color. However, there was a drawback that it lacked density and flatness.

Means for Solving the Problems As a result of various studies in view of the problems of the prior art as described above, the present inventor has developed a tin-lead alloy plating bath by adding a specific polyoxyalkylene bisphenol type surfactant. It has been found that, when added to a plating film, it is not only possible to substantially eliminate or significantly reduce the factor of foaming that reduces workability, but also to improve the stability of the plating bath and to significantly improve the properties of the plating film. Ta.

That is, the present invention provides a tin-lead alloy plating bath shown below.

■A tin product characterized by containing 1 to 200 g/Q of polyoxyalkylene bisphenol type surfactant.
Lead alloy plating bath: and ■Contains 1 to 200 g/Q of polyoxyalkylene bisphenol type surfactant and 0.1 to 20 z/Q of at least one of quinoline derivatives, indole derivatives, and aromatic amine compounds. Tin-lead alloy plating bath.

The polyoxyalkylene bisphenol type surfactant used in the present invention includes a compound represented by the following general formula (1).

General formula (1): (In the formula, each symbol means the following.

X: CH2CH20 R5 hydrogen atom and C1 to C5 alkyl group n1 and n2: number of 1 to 20, nI=n2.

m, and m2: a number from 0 to 10, mH=m2.

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 added in amounts of 1 to 10%.
Blend at a rate of 200g/l.

If the compounding ratio is less than 1 g/Q, the effects such as improving the stability of the plating bath and the leveling of the plating film will not be sufficiently achieved, while if it exceeds 200 g/Q, the plating The dissolution in the bath becomes insufficient and the foaming property increases.

In the present invention, the plating film can be made denser by further blending at least one of a quinoline derivative, an indole derivative, and an aromatic amine compound in addition to the above polyoxyalkylene bisphenol type surfactant. can.

As quinoline derivatives, 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-5,6-quinone, quinoline-5,8-quinone, quinoline-2,4-diol, Examples include 4-oxyquinaldic acid.

Examples of indole derivatives include indole, 3-methylindole, 2,3-dimethylindole, 2, 3.
3-) Dimethylindole, 1-chloroindole, β
-Dimethylaminoindole, indole-3-aldehyde, 3-indole, 1-chloroindole, 3-bromoindole, 3-cyanoindole, 6-nitroindole-3-aldehyde, 5-nitroindole-aldehyde, etc. .

Aromatic amine compounds include aniline, o-toluidine, m-)luidine, p-toluidine, O-nitroaniline, m-nitroaniline, p-nitroaniline, 2
．． 3-dimethylaniline, 2゜4-dimethylaniline,
N,N-dimethylaniline, 0-aminophenol, p
-Aminophenol, 2,4.6-drimethylaniline, 2.5-dinitroaniline, 1.8-naphthalene diamine, 1.5-naphthalene diamine, α-naphthylamine, β-naphthylamine, sodium naphthionate, 1
Examples include -naphthylamine-6-sulfonic acid, 1-naphthylamine-8-sulfonic acid, and p-nitrosodiphenylamine.

The 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 20 g/l. If the amount of these compounds is 0. If it is less than 1 g/l, the effect will not be improved sufficiently, while if it exceeds 20 g/l, it will be difficult to completely dissolve in the plating bath, which will be economically disadvantageous.

The components other than the above-mentioned 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 additives in a predetermined ratio into a known tin borofluoride-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. Moreover, the obtained plating film is extremely dense and exhibits good soldering properties.

EXAMPLES Examples and comparative examples are shown below to further clarify the features of the present invention.

In addition, the state observation of the plating film in Examples and Comparative Examples was performed by a Hull cell test. In the Hull Cell test,
The bath temperature was 25°C, and the current IA was applied for 5 minutes or the current 0.
Plating was performed at 5 A for 5 minutes, and 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 plated film were investigated.

45% tin-borofluoride 100 g: / 94
5% leadenium borofluoride 40 g / 942% hydroborofluoric acid 300 g / Q Inventive additive
40 g/l (in general formula (1), R
= methyl, ethylene oxide 10 mole additive) The plating film is white, and the scanning electron micrograph (640
0x), it was confirmed that the film 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 / 245% leadenous borofluoride 60 g / 942% hydrofluoroboric acid 300 g / Q fluoride
Acid 10g1Q Inventive additive 20g/l (general formula (
In 1), R = methyl, 12 moles of ethylene oxide, 1 mole of propylene oxide adduct) 2-methyl-8-hydroxyquinoline 0.5 g/l2
By blending -methyl-8-hydroxyquinoline, a uniform and dense white plating film could be obtained in a wider current density range than in Example 1.

Comparative Example 1 Plating was performed using a known tin-lead plating bath having the composition shown below, and the characteristics of the resulting plating film were investigated.

45% stannous borofluoride 100 g / 245% leadenium borofluoride 40 g / 942% hydrofluoroboric acid 300 g / Q polyoxyethylene nonylphenyl ether 40 g / 9 (ethylene oxide 10 mole adduct) Obtained plating The entire film 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 performed using a known tin-lead plating bath having the composition shown below, and the characteristics of the resulting plating film were investigated.

45% stannous borofluoride 120 g / 945
%Leadium borofluoride 50 g / 942% borofluoride 240 g / Q polyoxyethylene octylphenyl ether 40 g / Q (ethylene oxide 15 mole adduct) peptone
As in the case of Comparative Example 1, the plated film obtained at 5 g/l had a dark black color as a whole, and black spongy deposits were observed in the high current density areas.

Furthermore, scanning electron micrographs (6400x magnification) confirmed that the denseness 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 20 g/Q Lead phenolsulfonate 10 g/l phenolsulfonic acid 70 g 1Q Inventive additive
20 g/l (in general formula (1), R = methyl, 20 mole adduct of ethylene oxide) 8-hydroxyquinoline 5 g/l Example 4: 45% stannous borofluoride 120 g / 945
%Leadium borofluoride 60g/l42% Hydrofluoroboric acid 300g1Q Inventive additive
20 g/l (in general formula (1), R = ethyl, 20 mol of ethylene oxide, 2 mol of propylene oxide adduct) 2-methylquinoline 1 g/l Example 5: 45% stannous borofluoride 160 g/Q45
% leadenium fluoride 80 g / 942% fluoroboric acid 240 g/l Inventive additive
50 g/Q (in general formula (1), R-hydrogen, however, 10 moles of ethylene oxide and 4 moles of propylene oxide are randomly added) Quinoline-5,6-quinone 0.1 g/l Example 6 : Stannous acetate 30 g / Q Leaden acetate 10 g / Q Citric acid 70 g 1 Q Inventive additive
20g/Ω (in general formula (1), R
= hydrogen, 12 mole adduct of ethylene oxide) 3-methylindole 2 g/Q Example 7: 45% stannous borofluoride 60 g/945
%Leadium borofluoride 30, g/942%
Hydrofluoroboric acid 200g/l Inventive additive
20 g/l (in general formula (1), R
= methyl, but 12 moles of ethylene oxide and 4 moles of propylene oxide are added in block form) Indole 1 g/l Example 8: Stannous chloride 40 g/l nitrate
10 g/l Sodium gluconate 100 g/Q Inventive additive
20 g/Q (in general formula (1), R
= methyl, 15 moles of ethylene oxide, 3 moles of propylene oxide adduct) β-dimethylaminomethylindole 0.2 g: /l Example 9: Tin methanesulfonate 30 g / Q lead methanesulfonate 10 g / Q methanesulfonic acid 100 g/Q Inventive additive 20 g/l (In general formula (1), R = methyl, 15 mole adduct of ethylene oxide) 2.4-dimethylaniline 1 g/Q8-
Hydroxyquinoline 0.5 g/l Example 10; 45% stannous borofluoride 30 g/Q45
%Leadium borofluoride 10g, 142% Hydroborofluoride acid 100g/Q Inventive additive
20 g/Q (in general formula (1), R=hydrogen, 12 moles of ethylene oxide, 5 moles of propylene oxide adduct) Example 11: Stannous acetate 60 g/Q Lead acetate 20 g/Q Gluconic acid Sodium 150g:/12 Inventive additive
20 g/Q (in general formula (1), R = methyl, 10 mole adduct of ethylene oxide) β-naphthylamine 2 g/Q Example 12: 45% stannous borofluoride 120 g/l 45% leadenium borofluoride 60g/l 42% fluoroboric acid 350g/Q Inventive additive
20 g/l (R-methyl, 10 mole adduct of ethylene oxide in general formula (1)) 1.8-naphthalene diamine 1 g / Q Example 13: Tin phenolsulfonate 100 g / Q Lead phenolsulfonate 40 g / Q phenolsulfonic acid 200 g / Q additive of the present invention 15 g/l (In general formula (1), R-ethyl, however, 1 mol of ethylene oxide and 7 mol of propylene oxide are randomly added)
Sodium naphthionate 0.5g/! 2 Example 1
4: 45% tin-borofluoride 100 g/Q45
%Leadium borofluoride 40 g/Q4296
Hydroborofluoric acid 200 g/Q Inventive additive 20 g/l (in general formula (1), R-methyl, 17.5 mol adduct of ethylene oxide) Quinoline 1 g/l 1-naphthylamine-8-sulfonic acid 0.5 g /Ω- Example 3
When plating was performed using each of ~14 plating baths, a uniform white plating film was obtained over a wide current density range.

All of these films were dense and showed good solderability.

Example 15 Using a tin-lead plating bath having 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 an IQ measuring cylinder containing a plating solution, air was pumped in, and the height (mm) of foaming was measured after 30 seconds. The air supply capacity of the pump used was approximately 650 ml per 30 seconds.

In addition, as six defoaming tests, after stopping the air supply by the above pump, 30 seconds, 1 minute, 2 minutes, and 3
The foaming height (mm) was measured after minutes.

The results are shown in Table 1.

45% tin-borofluoride 90 g / 945
%Leadium borofluoride 10g/l42% Hydrofluoroboric acid 240g/QAdditive of the present invention
50g/l (in general formula (1), R-
methyl, ethylene oxide 10 mole adduct) 8-hydroxyquinoline 2 g/Q Comparative Example 3 Using a tin-lead plating bath having the composition shown below, Example 1
The foaming and defoaming properties of the bath were examined in the same manner as in Example 5.

The results are also shown in Table 1.

45% stannous borofluoride 90 g / 245
%Leadium borofluoride 10 g / 942% Hydrofluoroboric acid 240 g/l Polyoxyethylene nonylphenyl ether 50 g/l (ethylene oxide 10 mole adduct) Peptone
5 g / Q 1st table Foaming property Defoaming property (30 seconds) (30 seconds) (1 minute) (2 minutes) (3 minutes) From the results shown in Table 1 of Examples, Compared to known plating baths, the plating bath according to the present invention has approximately half the foaming property. It also has excellent antifoaming properties.

(And more) Procedures? A5 official document (spontaneous) April 25, 1988 1 Indication of the case Patent Application No. 70953 of 1988 2 Name of the invention Tin-lead alloy plating bath 3 Relationship with the amended party Patent applicant Okuno Pharmaceutical Co., Ltd. Agent Co., Ltd. 4' Sawanotsuru Building, 2-10 Hirano-cho, Higashi-ku, Osaka City 6 Section 7 of "Detailed Description of the Invention" in the specification subject to amendment Contents of amendment 1 Contents of amendment 1 Specification page 18 The statement in lines 10 to 12, "However, ethylene oxide...7 moles" is corrected as follows.

"However, 15 moles of ethylene oxide and 5 moles of propylene oxide" (hereinafter referred to as "2")

Claims (2)

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