JP3336621B2 - Composition solution for plating and plating method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating solution, and more particularly, to a plating solution (hereinafter, referred to as high-speed plating, which is referred to as high-speed plating by those skilled in the art). Plating bath or simply a plating solution).

[0002]

2. Description of the Related Art In recent years, plating plants have been demanding continuous plating of a body to be plated (a material for plating) in order to improve productivity, and high-speed plating has been performed in some parts. For high-speed plating, it is necessary to apply a large current to the plating bath to form a bath having a high current density. In conventional high-speed plating, for example, tin plating for obtaining a tin steel sheet, a high current is applied to the plating bath to make the plating bath in a fluid state and apply a large current to the bath.

Conventional techniques for plating at a high current density include (a) nonionic surfactants, cationic surfactants, heterocyclic compounds (or derivatives thereof such as 8-oxyquinoline, etc.) and 1,4- or 1,7
A solder plating bath containing dihydroxynaphthalene and corresponding to a high current density of 110 A / dm ² (Japanese Patent Laid-Open No. 1-96
No. 391, JP-A-1-96392, JP-A-1-156490), (b) α-naphtholsulfonic acid ethylene oxide adduct and polyoxyalkylene cumylphenol as components which are stable and low foaming at a high bath temperature Using ether (all surfactants), current density 100A / dm ²
A solder plating bath (JP-A-3-94093 and JP-A-3-94094) which can be used to a maximum extent, (c) containing an alkylpyridinium salt and an unsaturated carbonyl compound, at a high temperature of 50 ° C. or more and at a rate of about 3 m / sec. Current density of 100
A tin plating bath corresponding to A / dm ² (Japanese Patent Publication No. 1-20240) is known.

[0004]

However, the above-mentioned conventional plating bath for high-speed plating uses a high-speed jet (10 to 10).
High-speed plating at a high current density cannot be performed unless the liquid flow management is controlled by applying 30 m / sec), and the liquid flow control for obtaining a stable plating film is difficult and requires skill. Further, the above-mentioned prior art (a) discloses that the plating bath contains 1,4- or 1,7-dihydroxynaphthalene to cope with a high current density of 110 A / dm ^2. However, there is a problem that the nitrogen-containing heterocyclic compound 8-oxyquinoline or the like used as a compound is expensive and difficult to carry out because it is a carcinogenic substance. Further, the plating baths of the prior arts (b) and (c) must be a high-speed jet at a high temperature, and there is a problem that the bath management is difficult.

[0005] The object of the present invention was made in view of the above-mentioned conventional problems. Needless to say, the drug used is inexpensive and has no carcinogenicity. And no high-speed jet is required, for example, room temperature 30 ° C
Under low-temperature, low-speed stirring and easy-to-manage bath conditions,
It is an object of the present invention to provide a plating solution that can provide a high current density and is suitable for high-speed (short-time) plating of an acidic plating bath or a weakly acidic plating bath.

[0006]

Means for Solving the Problems In the study of high-speed plating, the present inventors have studied the use of a metal ion, a conductive acid or a salt thereof, a nonionic surfactant or an ionic surfactant having a polyoxyalkylene group. Including plating bath composition,
As a result of an experiment, it was found out that a phenanthroline-based compound was included, and high-speed plating with extremely high current density tolerance was possible, thereby achieving the present invention.

That is, the invention for achieving the above-mentioned object includes a metal ion, a conductive acid or a salt thereof, and a nonionic surfactant or an ionic surfactant having a polyoxyalkylene group. Current density based on an acidic or weakly acidic composition solution and containing at least one phenanthroline compound at 0.0001 to 10 g / L
It features a high-speed plating solution of 30 A / dm ² or more . Also
The present invention provides a method for preparing a metal ion, a conductive acid or a salt thereof,
Has an ionic surfactant or polyoxyalkylene group
Acidic to weakly acidic surfactants
Composition based and at least one phenant
Plating set containing 0.0001 to 10 g / L of a loline compound
High-speed plating at a current density of 30 A / dm ² or more using a component solution
It features a plating method. More specifically, the present invention
Sn or solder metal ion and conductive acid or its salt
And a nonionic surfactant or polyoxyalkylene
An ionic surfactant having a group,
It is based on a weakly acidic composition liquid and contains at least one
Containing 0.0001 to 10 g / L of an enanthroline compound,
It is a composition solution for high-speed plating having a current density of 30 to 100 A / dm ² .

[0008] Plating using the above acidic or weakly acidic plating solution is mainly tin plating, solder (tin-tin).
Lead alloy) plating and zinc plating. These platings can be applied both as bright plating and as dull to semi-glossy plating.

The composition of the plating solution for tin plating or solder plating is basically a divalent tin salt, such as stannous sulfate,
Stannous chloride, stannous borofluoride, stannous alkanolsulfonate, or stannous methanesulfonate, stannous phenolsulfonate, stannous cresolsulfonate, stannous acetate, and the like, Examples of the lead salt include lead chloride, lead borofluoride, lead alkanol sulfonate, lead methane sulfonate, lead phenol sulfonate, lead cresol sulfonate, lead acetate, lead oxide and the like. And, as conductive acids or salts, sulfuric acid, hydrochloric acid, borofluoric acid, acetic acid, alkanolsulfonic acid, methanesulfonic acid, phenolsulfonic acid, cresolsulfonic acid, citric acid, malic acid, tartaric acid, boric acid, etc. Acids and one or more selected from ammonium salts, sodium salts, potassium salts and the like thereof can be used.

[0010] The composition of the plating solution for zinc plating is as follows:
Examples of the zinc salt include zinc chloride, zinc sulfate, zinc acetate, zinc carbonate, zinc oxide, and the like.Examples of the conductive acid or salts include acids such as hydrochloric acid, sulfuric acid, acetic acid, boric acid, and ammonium salts and sodium salts thereof. One or more selected from salts, potassium salts and the like can be used.

The nonionic surfactant or ionic surfactant is contained in the plating bath at a concentration of 0.5 to 40 g / L.

The nonionic surfactants include polyoxyalkylene alkylphenol ethers, polyoxyalkylene higher alcohol ethers, polyoxyalkylene-α- or β-naphthol ethers, polyoxyalkylene-mono-, di- or tri-styrene. Phenol ether, polyoxyethylene-polyoxypropylene-block polymer, polyoxyethylene-polyoxypropylene condensate of ethinonediamine, polyoxyalkylene-added alkylamine, polyoxyalkylene-added alkylamide and the like are used.

Examples of the ionic surfactant having a polyoxyalkylene group include anionic surfactants such as alkylphenoxypolyoxyalkyleneethylsulfonic acid and salts thereof, higher alcohol polyoxyalkyleneethylsulfonic acid and salts thereof, and the like. Cationic surfactants such as N, N-dipolyoxyalkylene-N, N-dialkylammonium hydrochloride are used.

The plating bath may further contain other cationic surfactants, amphoteric surfactants such as N-monoalkyl-N-trimethylammonium salt, N, N-dialkyl-N-dimethylammonium salt, Cationic surfactants such as N-alkyl-isoquinolinium salt, 1-alkyl-1-hydroxyethyl-imidazolium salt, 1-hydroxyethyl-1-carboxyalkylene-2-alkylimidazolium betaine, N, N-dimethyl- N-
An amphoteric surfactant such as alkyl betaine can be added as needed. The surfactant is used in a total concentration of 0.5 to 40 g / L in the bath, and a desirable concentration is 1 to 30 g / L.

Although not required for zinc plating, tin plating,
In solder plating, an antioxidant such as catechol or hydroquinone is preferably used in combination to prevent oxidation of tin (Sn ²⁺ ). The concentration of these antioxidants in the bath is 0.05 to 20 g / L, and the preferable concentration range is 0.1 to 20 g / L.
It is 15 g / L.

Bright plating in tin plating and solder plating is carried out by using an aromatic carbonyl compound as a gloss imparting component, for example, benzaldehyde, o-chlorobenzaldehyde, tolualdehyde, anisaldehyde, cinnamaldehyde, 2,5-dimethoxybenzaldehyde,
Aromatic aldehydes such as-or 2-naphthaldehyde,
Aromatic ketones such as benzylideneacetone and alkylnaphthyl ketone are used. Also, as an auxiliary brightener component,
Aliphatic aldehydes such as formaldehyde and acetaldehyde, and aromatic amines such as o-, m- or p-aminophenol and sulfanilic acid can be used.
These gloss imparting components and auxiliary brightener components may be used alone or in combination of two or more, if necessary.

In the case of zinc plating as well, if necessary, as an auxiliary brightener, an aliphatic amine such as polyethyleneimine, an amine such as an epihalohydrin reaction product of an aliphatic amine, or a salt of benzoic acid (ammonium, Potassium or sodium salts), salts of chloro-substituted benzoic acids (ammonium, potassium or sodium salts), and the like.

The gloss-imparting component and the auxiliary gloss-imparting component are used in the bath in an amount of 0.005 to 5 g / L.
A desirable concentration is 0.01 to 2 g / L, the auxiliary brightener component is 0.01 to 30 g / L in the bath, and a desirable concentration is 0.05 to 15 g / L.

The phenanthroline compound is 1,1
0-phenanthroline, 2,9-dimethylphenanthroline, 3,4,7,8-tetramethylphenanthroline, 4,7-dihydroxyphenanthroline, 4,7-
Diphenyl-1,10-phenanthroline (vasophenanthroline), 4,7-diphenyl-2,9-dimethylphenanthroline (basocuproine), 4,7-diphenyl-1,10-phenanthroline-disulfonic acid and salts thereof (basophenanthroline disulfonic acid) And its salts), 4,7-diphenyl-2,9-dimethyl-1,1
0-phenanthroline-disulfonic acid and its salt (basocuproin disulfonic acid and its salt) and the like are used.

As the phenanthroline-based compound, at least one of the compounds exemplified above can be used alone or in combination. The concentration of the phenanthroline compound in the plating bath is 0.0001 to 10 g /
L, preferably 0.001 to 1 g / L. When the amount of the phenanthroline compound is less than 0.0001 g / L, high current density durability cannot be obtained in the plating bath, and when the amount exceeds 10 g / L, electrodeposition of the plating film is extremely suppressed and a predetermined film thickness can be obtained. Absent.

As can be seen from the above-mentioned concentrations, the characteristics of the phenanthroline-based compound are slightly different depending on the structure of the compound, but are generally effective with a very small amount of addition. To several tens of ppm.
Plating at about 100 A / dm ² can be carried out at room temperature even under insufficient stirring conditions, and a surprising effect is exhibited. The phenanthroline compound can also be used in a gloss bath, and it is necessary to slightly increase the amount of addition due to the effect of a gloss-imparting component and an auxiliary brightener. Even at an addition concentration of about several g / L, a strong enhancement effect of the high current density portion can be obtained, and the use concentration of the gloss imparting component can be significantly reduced, which is extremely useful.

[0022]

In the present invention, the nonionic surfactant and the ionic surfactant act to improve and control the deposition of the plating film. The phenanthroline-based compound has an action capable of achieving a high current density in a low-temperature or low-temperature stirring bath such as at room temperature.

[0023]

Next, embodiments of the present invention will be described. (Example 1) Under the plating bath shown in Table 1 and the following plating conditions A, the object to be plated was subjected to bright tin plating.

[0024]

Plating condition A Cathode current density: 5, 10, 30, 60, 100 A
/ Dm ² . Plating time at each stage: current density × time = 10 Amin.
/ Dm ² . Cathode: Platinum-plated titanium plate Bath temperature: 30 ° C Stirring: Slow stirrer Stirring object: Copper-plated steel plate of about 2 μm The results of plating at the current density of each stage are shown in Table 2. there were.

[0026]

[Table 2]

The film thickness was measured with a fluorescent X-ray micro-film thickness meter. As is clear from Table 2, in Example 1, 5 to 1
In a wide current density range of 00 A / dm ² , an excellent glossy appearance was obtained and a sufficient film thickness was obtained.

(Comparative Example 1) Plating was carried out under the same conditions and under the same conditions as in Example 1 using a plating bath having a liquid composition obtained by removing 1,10-phenanthroline from the components of the plating bath shown in Table 1.

[0029]

As is evident from Table 3, when the liquid composition excluding 1,10-phenanthroline was used, the film thickness of the plating film was reduced at 30 A / dm ² or more.

(Example 2) Semi-bright solder plating was performed on an object to be plated under a plating bath shown in Table 4 and the following plating conditions B.

[0032]

Plating condition B Cathode current density: 5, 10, 30, 50, 70, 1
There were six levels of 00 A / dm ² . Plating time at each stage: current density × time = 10 Amin.
/ Dm ² . Cathode: Platinum-plated titanium plate Bath temperature: 30 ° C Stirring: Slow stirrer Stuck body: Approximately 2 μm nickel-plated phosphor bronze plate The results of plating at the current density of each stage are shown in Table 5. It was as shown.

[0034]

[Table 5]

As apparent from Table 5, in Example 2, 5
In a wide current density range of １００100 A / dm ² , a uniform and dense semi-glossy plating film is obtained, and deposition is performed with extremely stable current efficiency even though the plating bath is not sufficiently stirred. Was recognized. In Example 2, the correlation between the metal composition ratio in the plating bath and the metal composition ratio of the deposited film was also good. In addition, the plating bath composition of Example 2 had extremely low foaming in the above wide current density.

(Comparative Example 2) Using a plating bath having a liquid composition obtained by removing 2,9-dimethyl-1,10-phenanthroline from the components of the plating bath shown in Table 4, under the same conditions and under the same method as in Example 2 Plating was performed. The results of the plating were as shown in Table 6.

[0037]

As is apparent from Table 6, in the liquid composition excluding 2,9-dimethyl-1,10-phenanthroline,
Above 30 A / dm ² or more, abnormal deposition of the plating film (gray deposition to black deposition) was accompanied by a sharp decrease in the film thickness and lead eutectoid rate.

Example 3 In the plating bath composition of Example 2 (Table 4), 0.01 g / L of 2,9-dimethyl-1,10-phenanthroline was added to 3,4,7,8-tetramethylphenanthroline. Using a plating bath replaced with 0.05 g / L of the above, the object to be plated was subjected to semi-bright solder plating under the same conditions and under the same method as in Example 2. The results of the plating were as shown in Table 7.

[0040]

[Table 7]

In the third embodiment, 5 to 100
At a wide current density of A / dm ² , a uniform and dense semi-bright plating film was obtained, and it was recognized that the correlation between the metal composition ratio in the bath and the metal composition ratio of the deposited film was good.

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

As apparent from Examples 1 to 3 and Comparative Examples 1 to 3 described above, 1,10-phenanthroline,
2,9-dimethyl-1,10-phenanthroline, 3,
It is recognized that the plating bath containing 4,7,8-tetramethylphenanthroline and bathophenanthroline can easily obtain a high current density of 100 A / dm ² despite gentle stirring at a bath temperature of 30 ° C. Further, in the plating baths of Examples 1 to 3 , it was possible to perform plating with a sufficient film thickness in a wide range of current density.

Next, in each of the plating baths of Examples 1 to 3 , high-speed plating of tin, solder, and zinc was performed in a factory plating tank with a low-speed jet (5 m / min) at a bath temperature of 35 ° C. In each case, a uniform plating film was obtained without any burning or fogging. This is the limit of the high current density side in a conventional plating bath, to generate the abnormal deposition of such burnt and fogging when lowering or extreme of the current efficiency, the cathode of the metal ions in the plating bath of Example 1-3 By suppressing the formation of hydroxide on the surface, plating can be performed based on high current efficiency. In Examples 1 to 3 , 100 A / dm ² even when the plating bath was hardly agitated.
Plating was possible with a current as high as possible.

[0052]

Since the present invention is a plating bath containing a phenanthroline-based compound, a high current density can be obtained under easy-to-manage bath conditions, for example, at a low temperature of 30 ° C. with low-speed stirring or without stirring. can get. The present invention is suitable for high-speed (short-time) plating of tin, solder, zinc, or the like because a high current density can be easily obtained and an acidic plating bath or a weakly acidic plating bath is used. Also,
The phenanthroline compound in the present invention is inexpensive, unlike, for example, conventional 8-oxyquinoline and the like,
It is convenient because it is a drug that does not have carcinogenic potential.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-219187 (JP, A) JP-A-3-215692 (JP, A) JP-A-2-232389 (JP, A) JP-A-63- 128194 (JP, A) JP-A-60-159190 (JP, A) U.S. Pat. No. 4,923,576 (US, A) U.S. Pat. No. 4,981,564 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C25D 3/00-3/66

Claims (3)

(57) [Claims] 1. An acidic or weakly acidic composition liquid containing a metal ion, a conductive acid or a salt thereof, and a nonionic surfactant or an ionic surfactant having a polyoxyalkylene group. And contains at least one phenanthroline compound at 0.0001 to 10 g / L ,
Composition solution for high-speed plating with current density of 30 A / dm ² or more . 2. A metal ion, a conductive acid or a salt thereof.
And a nonionic surfactant or polyoxyalkylene
An ionic surfactant having a group,
It is based on a weakly acidic composition liquid and contains at least one
Contains 0.0001 to 10 g / L of enanthroline compound
Plating at a current density of 30 A / dm ² or more using a plating solution
Perform high-speed plating method. 3. A metal ion of Sn or solder and conductive metal
An acid or a salt thereof and a nonionic surfactant or polio
An ionic surfactant having a xyalkylene group;
Based on acidic or weakly acidic composition
0.0001-10 g of at least one phenanthroline compound
/ L containing, current density 30-100A / dm ^Two For high-speed plating
Liquid.