JP3263750B2 - Acidic copper plating bath and plating method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an acidic copper plating bath and a plating method using the plating bath.

[0002]

2. Description of the Related Art A copper sulfate plating bath containing copper sulfate, sulfuric acid and chlorine ions as basic components (hereinafter simply referred to as a plating bath unless otherwise required) has a higher activation polarization than a copper cyanide plating bath. Due to the small size, the uniform electrodeposition property is low, and the precipitated particles are coarse. Therefore, if the current density is increased or the bath temperature is increased for the purpose of increasing the plating speed, the uniformity of the plating is further reduced, and the plating having low smoothness and low gloss is formed.

In order to prevent poor appearance and deterioration in physical properties due to smoothness, glossiness, and the like in high current density and high temperature bath plating, many studies have been made in the past, and many additives have been proposed and put into practical use. It has also been transformed. Representative additives include so-called brighteners, throwing power improvers, spreadability improvers, hardeners, smoothing agents, and the like. In many cases. In some cases, a greater effect may be obtained when two or more of these are used in combination than when used alone.

In a conventional plating bath, the cathode current density is 1 to 5
A / dm ² , more preferably 2-3 A / dm ² , bath temperature 15-35 ° C., more preferably 20-3
In plating at about 0 ° C. and a plating time of about 5 to 40 minutes, more preferably about 15 to 30 minutes, a copper plating film having good gloss, uniform electrodeposition, spreadability, hardness, smoothness, and the like can be obtained.

However, in order to strictly control the plating bath within the above-described narrow range of the cathode current density and the temperature, a cooling device and the like are required, and a high management cost is required. .

For this reason, there is a need for a plating method that is not limited to the above-mentioned current density and temperature. However, with a conventional plating bath, a plating film having sufficient gloss and smoothness cannot be obtained at a current density and temperature other than the above ranges. This phenomenon tends to become more remarkable as the current density deviates from the above range or as the bath temperature increases. Particularly in the case of a high current density, a conventional plating bath forms dendritic or sponge-like copper deposits on the plating surface.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to a range other than the conventional current density and temperature, namely, 0.1 to 1 and 5 to 10
A main object of the present invention is to provide a plating bath having excellent appearance and physical properties even in plating of a current density of A / dm ² and a high-temperature bath of 30 to 35 ° C.

[0008]

Means for Solving the Problems The present inventor has conducted intensive studies in view of the state of the art as described above, and as a result, has found that the use of a plating bath containing a specific compound has resulted in a reduction of 0.1%.
To 1 and 5~10A / dm ² of current density and 30 to 3
It has been found that even in plating at a high temperature of 5 ° C., copper plating having excellent appearance and physical properties can be obtained.

That is, the present invention provides the following plating bath and plating method using the same.

[0010] 1. An acidic copper plating bath having a basic composition of copper sulfate, sulfuric acid and chloride ions, wherein (1) a general formula:

[0011]

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[Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ ,
R ₆ and R ₇ are the same or different and are atoms or groups selected from the group consisting of a hydrogen atom, a hydroxyl group, a sulfonic acid group and an amino group. n is a number ranging from 2 to 500. (Hereinafter referred to as nitrogen-containing organic compound A)
At least one of 0.05 to 0.
2 g / l, (2) General formula: M ₁ SO ₃ —R ₈ —R ₉ — (S) _m —R
₁₀ wherein M ₁ is a hydrogen atom, an alkali metal or ammonium.

R ₈ is an oxygen atom or an alkylene bridging group having 1 to 5 carbon atoms, R ₉ is an alkylene bridging group having 1 to 5 carbon atoms, R ₁₀ is a hydrogen atom, a metal atom, and a 1 to 10 carbon atoms. An aliphatic alkyl group or an aromatic alkyl group having 6 to 10 carbon atoms, a group represented by the general formula: M ₁ SO ₃ —R ₈ —R ₉ — (M ₁ , R
₈ and R ₉ are the same as described above), or a general formula:

[0014]

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Wherein R ₁₁ and R ₁₂ are the same or different and each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. m is 1-5. At least one of the compounds represented by the formula (hereinafter sometimes referred to as sulfur-containing organic compound B): 0.005 to 0.1 g / l;

[0016]

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Wherein R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ are represented by the general formula:

[0018]

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(Wherein, M ₂ represents a hydrogen atom, an alkali metal, or ammonium, z is 1 to 5, x and y are 1 to 5)
It is a group represented by 10). p is 1-5. (Hereinafter sometimes referred to as sulfur-containing organic compound C) in an amount of 0.01 to 0.05 g /
l, (4) polypropylene glycol, polyethylene glycol having an average molecular weight of 200 to 100,000 for each,
Compounds selected from the group consisting of polyoxyethylene olein ether, polyoxyethylene lauryl ether and polyoxyethylene nonylphenyl ether (hereinafter, referred to as
0.04 to 0.08 g / l of at least one polyether compound D), and (5) a general formula:

[0020]

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Wherein R ₁₇ is an alkylene bridging group having 1 to 4 carbon atoms, R ₁₈ is an alkylene bridging group having 1 to 3 carbon atoms,
R ₁₉ is an alkylene bridging group having 1 to 3 carbon atoms, R ₂₀ is an alkyl group having 1 to 10 carbon atoms, and R ₂₁ is a 1 to 10 carbon atoms.
Is an alkyl group. q is 2 to 500. At least one of the compounds represented by the formula (hereinafter sometimes referred to as nitrogen-containing organic compound E):
An acidic copper plating bath characterized by containing

2. A plating method using an acidic copper plating bath having a basic composition of copper sulfate, sulfuric acid and chloride ions, wherein (1) a general formula:

[0023]

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[Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ ,
R ₆ and R ₇ are the same or different and are atoms or groups selected from the group consisting of a hydrogen atom, a hydroxyl group, a sulfonic acid group and an amino group. n is a number ranging from 2 to 500. (Hereinafter referred to as nitrogen-containing organic compound A)
At least one of 0.05 to 0.
2 g / l, (2) General formula: M ₁ SO ₃ —R ₈ —R ₉ — (S) _m —R
₁₀ wherein M ₁ is a hydrogen atom, an alkali metal or ammonium.

R ₈ is an oxygen atom or an alkylene bridging group having 1 to 5 carbon atoms, R ₉ is an alkylene bridging group having 1 to 5 carbon atoms, R ₁₀ is a hydrogen atom, a metal atom, or a 1 to 10 carbon atoms. An aliphatic alkyl group or an aromatic alkyl group having 6 to 10 carbon atoms, a group represented by the general formula: M ₁ SO ₃ —R ₈ —R ₉ — (M ₁ , R
₈ and R ₉ are the same as described above), or a general formula:

[0026]

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Wherein R ₁₁ and R ₁₂ are the same or different and each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. m is 1-5. At least one of the compounds represented by the formula (hereinafter sometimes referred to as sulfur-containing organic compound B): 0.005 to 0.1 g / l;

[0028]

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Wherein R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ are represented by the general formula:

[0030]

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(Wherein, M ₂ represents a hydrogen atom, an alkali metal, or ammonium, z is 1 to 5, x and y are 1 to 5)
It is a group represented by 10). p is 1-5. (Hereinafter sometimes referred to as sulfur-containing organic compound C) in an amount of 0.01 to 0.05 g /
l, (4) polypropylene glycol, polyethylene glycol having an average molecular weight of 200 to 100,000 for each,
Compounds selected from the group consisting of polyoxyethylene olein ether, polyoxyethylene lauryl ether and polyoxyethylene nonylphenyl ether (hereinafter, referred to as
0.04 to 0.08 g / l of at least one polyether compound D), and (5) a general formula:

[0032]

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Wherein R ₁₇ is an alkylene bridging group having 1 to 4 carbon atoms, R ₁₈ is an alkylene bridging group having 1 to 3 carbon atoms,
R ₁₉ is an alkylene bridging group having 1 to 3 carbon atoms, R ₂₀ is an alkyl group having 1 to 10 carbon atoms, and R ₂₁ is a 1 to 10 carbon atoms.
Is an alkyl group. q is 2 to 500. At least one of the compounds represented by the formula (hereinafter sometimes referred to as nitrogen-containing organic compound E):
A plating method using an acidic copper plating bath containing l.

The acidic copper plating bath used in the present invention has a basic composition of copper sulfate (CuSO ₄ .5H ₂ O), sulfuric acid (H ₂ SO ₄ ), and chlorine ion (Cl ⁻ ). The basic composition of such an acidic copper plating bath is not particularly limited, but typical examples are as follows.

The content of copper sulfate is 125 to 260 g / l
Degree, preferably about 150 to 250 g / l.

The sulfuric acid content is about 20 to 85 g / l,
Preferably, it is about 30 to 70 g / l.

The chlorine ion content is 0.01 to 0.1.
About 5 g / l, preferably 0.03 to 0.10 g / l
Degree.

The nitrogen-containing organic compound A is a polymer of azotized alizarin safilol. In the present invention, the nitrogen-containing organic compound A has an effect of improving the gloss and smoothness of plating by an adsorption phenomenon due to its wetting action.

In the nitrogen-containing organic compound A, n is usually about 2 to 500, more preferably 150 to 35.
It is about 0.

R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ and R ₇ may be the same or different and are selected from a hydrogen atom, a hydroxyl group, a sulfonic acid group and an amino group. Is done.

The content of the nitrogen-containing organic compound A is about 0.05 to 0.2 g / l, preferably about 0.08 to 0.18 g / l in the acidic copper plating bath of the present invention.

The sulfur-containing organic compound B acts mainly as a brightening agent.

Specifically, in the sulfur-containing organic compound B, m is usually about 1 to 5, more preferably about 2 to 4.

M ₁ is an alkali metal or ammonium. Examples of the alkali metal of M ₁ include sodium and potassium.

R ₈ is an oxygen atom or an alkylene bridging group having 1 to 5 carbon atoms. Examples of the alkylene bridging group for R ₈ include a methylene group, an ethylene group, and a propylene group.

R ₉ is an alkylene bridging group having 1 to 5 carbon atoms. Examples of the alkylene bridge group for R ₉ include a methylene group, an ethylene group, and a propylene group.

R ₁₀ represents a hydrogen atom, a metal atom, a carbon number of 1 to
It is an aliphatic alkyl group having 10 or an aromatic alkyl group having 6 to 10 carbon atoms. As the metal atom for R ₁₀ , potassium,
Sodium and the like are exemplified. Examples of the aliphatic alkyl group for R ₁₀ include a methyl group and an ethyl group. Examples of the aromatic alkyl group for R ₁₀ include a phenyl group.

Examples of the sulfur-containing organic compound B include sodium 3-mercaptopropane-1-sulfonate, bis-mercapto-oxy-methylene-di-sulfide, N, N
-Diethyl-dithiocarbamic acid- (sulfopropyl)
-Ester sodium salt, mercapto-benzothiazole-sodium S-propanesulfonate, o-ethyl-
Examples thereof include dithiolithic carbonate- (8-sulfopropyl) ester potassium salt.

The content of the sulfur-containing organic compound B is about 0.005 to 0.1 g / l in the acidic copper plating bath of the present invention.
Preferably, it is about 0.01 to 0.08 g / l.

The sulfur-containing organic compound C mainly acts as a spreadability improver and a throwing power improver.

Specifically, in the sulfur-containing organic compound C, p is usually about 1 to 5, preferably about 2 to 4.

R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ have the general formula:

[0053]

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And may be the same or different.

X is usually about 1 to 10, preferably 2 to
It is about 5.

Y is usually about 1 to 10, preferably 2 to
It is about 5.

Z is usually about 1 to 5, preferably 2 to 4
It is about.

M ₂ is hydrogen, an alkali metal, or ammonium. Sodium as the alkali metal of M ₂
Potassium and the like are exemplified.

As the sulfur-containing organic compound C, tetra-
Examples are polypropoxy-ethoxy-ethylenediamine-sulfo-succinate sodium salt.

The content of the sulfur-containing organic compound C is about 0.01 to 0.05 g / l in the acidic copper plating bath of the present invention.
More preferably, it is about 0.02 to 0.04 g / l.

The polyether compound D mainly acts as a throwing power improver and a surface smoothing improver. The polyether compound D has an average molecular weight of 200 to 1 for each.
At least one of 00000 polypropylene glycol, polyethylene glycol, polyoxyethylene olein ether, polyoxyethylene lauryl ether and polyoxyethylene nonylphenyl ether is used.

The content of the polyether compound D is usually about 0.04 to 0.08 g / l, preferably about 0.05 to 0.06 g / l in the acidic copper plating bath of the present invention.

The nitrogen-containing organic compound E mainly acts as a hardening agent and a leveling agent.

Specifically, in the nitrogen-containing organic compound E, q is usually about 2 to 500, preferably 50 to 30.
It is about 0.

R ₁₃ is an alkylene bridging group having 1 to 4 carbon atoms. Examples of the alkylene bridging group for R ₁₃ include a methylene group, an ethylene group, and a propylene group.

R ₁₄ is an alkylene bridging group having 1 to 3 carbon atoms. Examples of the alkylene bridging group for R ₁₄ include a methylene group, an ethylene group, and a propylene group.

R ₁₅ is an alkylene bridging group having 1 to 3 carbon atoms. Examples of the alkylene bridging group for R ₁₅ include a methylene group, an ethylene group, and a propylene group.

R ₁₆ is an alkyl group having 1 to 10 carbon atoms. Examples of the alkyl group for R ₁₆ include a methyl group, an ethyl group,
Examples thereof include a propyl group.

The content of the nitrogen-containing organic compound E is about 0.002-0.01 g / l, preferably about 0.005-0.01 g / l, in the acidic copper plating bath of the present invention.

The acidic copper plating bath of the present invention is prepared according to a general method. In the plating method using this acidic copper plating bath, the cathode current density is 0.1 to 10 A /
dm ² , preferably about ² to 6 A / dm ² .

The bath temperature is about 15 to 35 ° C., preferably about 20 to 30 ° C.

The plating time is about 8 to 40 minutes, preferably about 15 to 30 minutes.

[0073]

According to the plating method using the acidic copper plating bath of the present invention, a good plating film can be obtained even at a current density lower than usual or a current density higher than usual or a bath temperature higher than usual. Bath management costs can be greatly reduced.

Further, in the case of a high current density or a high bath temperature, the amount of the additive may be small, the plating time can be shortened, and the cost can be reduced.

[0075]

EXAMPLES Examples of the present invention will be described below.

In Examples and Comparative Examples of the present invention, copper sulfate 200 g / l, sulfuric acid 50 g / l, chloride ion 50 m / l
g / l of the basic bath, add the specified additives, and add
Plating was performed at 0 ± 1 ° C. When plating, 257
A Brass panel cathode, which was mirror polished with a 1000 ml Hull cell test tank, copper anode and cotton buff and then scratched with # 1000 emery paper, was used. The current was 2 A, the plating time was 10 minutes, and the range of the cathode current density was about 0.1 to 15 A / dm ^2.
Met.

COMPARATIVE EXAMPLE 1 Electroplating was carried out in a bath containing the following compounds as additives. As a result, a copper-plated panel having cloudiness in a low current portion and poor smoothness was obtained.

Sodium 3-mercaptopropane-1-sulfonate 0.02 g / l General formula:

[0079]

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Tetra-polypropoxy-ethoxy-ethylenediamine-sulfo-succinate sodium salt 0.05 g / l polypropylene glycol (average molecular weight: 11000) represented by: 0.10 g / l Example 1 As an additive, When electroplating was carried out in a bath containing the above compound, a glossy copper film was obtained on the entire surface of the panel, and the smoothness of the panel was also improved.

Sodium 3-mercaptopropane-1-sulfonate 0.02 g / l General formula:

[0082]

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Tetra-polypropoxy-ethoxy-ethylenediamine-sulfo-succinate sodium salt 0.05 g / l polypropylene glycol (average molecular weight: 11000) 0.10 g / l represented by the general formula:

[0084]

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The polymer of azonated alizarin safilol represented by 0.10 g / l of the general formula:

[0086]

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Comparative Example 2 Electroplating was carried out in a bath containing the following compound as an additive, and a copper-plated panel with cloudiness in a low current portion and poor smoothness was obtained. Obtained.

Bis- (3-sodium-sulfopropyl) -disulfide 0.02 g / l General formula:

[0089]

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Tetra-polypropoxy-ethoxy-ethylenediamine-sulfo-succinate sodium salt 0.05 g / l polypropylene glycol (average molecular weight: 12000) 0.02 g / l represented by the general formula:

[0091]

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Example 2 When electroplating was carried out in a bath containing the following compounds as additives, a glossy copper film was obtained on the entire surface of the panel, The smoothness has also been improved.

Bis-mercapto-oxy-methylene-disulfide 0.05 g / l General formula:

[0094]

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Tetra-polypropoxy-ethoxy-ethylenediamine-sulfo-succinate sodium salt 0.05 g / l polypropylene glycol (average molecular weight: 12000) 0.02 g / l represented by the general formula:

[0096]

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A cationic resin represented by the following formula: 0.005 g / l

[0098]

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0.12 g / l of an azylated alizarin saphilol polymer represented by: Comparative Example 3 Electroplating was carried out in a bath containing the following compounds as additives, and a glossy copper-plated panel was obtained. . However, the plating panel was poor in smoothness.

General formula:

[0101]

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0.10 g / l sodium 3-mercaptopropane-1-sulfonate represented by the following formula: 0.02 g / l

[0103]

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Tetra-polypropoxy-ethoxy-ethylenediamine-sulfo-succinate sodium salt 0.05 g / l of polypropylene glycol (average molecular weight: 13000) 0.05 g / l of the general formula:

[0105]

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Example 3 A cationic resin represented by the following formula: 0.01 g / l Example 3 When electroplating was carried out in a bath containing the following compounds as additives, a glossy copper film was obtained on the entire panel, and Was significantly improved.

General formula:

[0108]

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0.15 g / l bis-mercapto-oxy-methylene-disulfide polymer of azylated alizarin saphilol represented by: 0.08 g / l General formula:

[0110]

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Tetra-polypropoxy-ethoxy-ethylenediamine-sulfo-succinate sodium salt 0.05 g / l polypropylene glycol (average molecular weight: 13000) 0.05 g / l represented by the general formula:

[0112]

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A cationic resin represented by the following formula: 0.01 g / l

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-185992 (JP, A) JP-A-7-62587 (JP, A) JP-A-2001-247994 (JP, A) JP-A-5-230687 (JP, A) JP 2-46675 (JP, B2) (58) Fields surveyed (Int. Cl. ⁷ , DB name) C25D 3/38

Claims (2)

(57) [Claims] An acidic copper plating bath having a basic composition of copper sulfate, sulfuric acid and chlorine ions, wherein (1) a general formula: [Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ and R ₇
Are the same or different and are atoms or groups selected from the group consisting of a hydrogen atom, a hydroxyl group, a sulfonic acid group and an amino group. n is a number ranging from 2 to 500. 0.05 to 0.2 g / l of the compound represented by the general formula: M ₁ SO ₃ —R ₈ —R ₉ — (S) _m —R
₁₀ wherein M ₁ is a hydrogen atom, an alkali metal or ammonium. R ₈ is an oxygen atom or an alkylene bridging group having 1 to 5 carbon atoms, R ₉ is an alkylene bridging group having 1 to 5 carbon atoms, R ₁₀ is a hydrogen atom, a metal atom, or an aliphatic alkyl having 1 to 10 carbon atoms. A group or an aromatic alkyl group having 6 to 10 carbon atoms,
A group of the general formula: M ₁ SO ₃ —R ₈ —R ₉ — (M ₁ , R ₈ and R ₉ are the same as above), or a general formula: Wherein R ₁₁ and R ₁₂ are the same or different and each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
m is 1-5. At least one compound represented by the formula:
Seeds 0.005 to 0.1 g / l, (3) general formula: Wherein R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ are represented by the general formula: (Wherein, M ₂ represents a hydrogen atom, an alkali metal or ammonium, z is 1 to 5, x and y are 1 to 10). p is 1-5. 0.01 to 0.05 g / l of at least one compound represented by the formula: (4) polypropylene glycol, polyethylene glycol having an average molecular weight of 200 to 100,000 for each,
0.04 to 0.08 g / l of at least one compound selected from the group consisting of polyoxyethylene olein ether, polyoxyethylene lauryl ether and polyoxyethylene nonylphenyl ether; and (5) a general formula: 5] [Wherein, R ₁₇ is an alkylene bridging group having 1 to 4 carbon atoms, R ₁₈ is an alkylene bridging group having 1 to 3 carbon atoms, R ₁₉ is an alkylene bridging group having 1 to 3 carbon atoms, R ₂₀ is The alkyl group having 1 to 10 carbon atoms and R ₂₁ are an alkyl group having 1 to 10 carbon atoms. q is 2 to 500. At least one compound represented by the formula
An acidic copper plating bath characterized by containing about 0.01 g / l. 2. A plating method using an acidic copper plating bath having a basic composition of copper sulfate, sulfuric acid and chloride ions, wherein (1) a general formula: [Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ and R ₇
Are the same or different and are atoms or groups selected from the group consisting of a hydrogen atom, a hydroxyl group, a sulfonic acid group and an amino group. n is a number ranging from 2 to 500. 0.05 to 0.2 g / l of the compound represented by the general formula: M ₁ SO ₃ —R ₈ —R ₉ — (S) _m —R
₁₀ wherein M ₁ is a hydrogen atom, an alkali metal or ammonium. R ₈ is an oxygen atom or an alkylene bridging group having 1 to 5 carbon atoms, R ₉ is an alkylene bridging group having 1 to 5 carbon atoms, R ₁₀ is a hydrogen atom, a metal atom, or an aliphatic alkyl having 1 to 10 carbon atoms. A group or an aromatic alkyl group having 6 to 10 carbon atoms,
A group of the general formula: M ₁ SO ₃ —R ₈ —R ₉ — (M ₁ , R ₈ and R ₉ are the same as described above), or a general formula: Wherein R ₁₁ and R ₁₂ are the same or different and each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
m is 1-5. At least one compound represented by the formula:
Seeds 0.005 to 0.1 g / l, (3) general formula: Wherein R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ are represented by the general formula: (Wherein, M ₂ represents a hydrogen atom, an alkali metal or ammonium, z is 1 to 5, x and y are 1 to 10). p is 1-5. 0.01 to 0.05 g / l of at least one compound represented by the formula: (4) polypropylene glycol, polyethylene glycol having an average molecular weight of 200 to 100,000 for each,
0.04 to 0.08 g / l of at least one compound selected from the group consisting of polyoxyethylene olein ether, polyoxyethylene lauryl ether and polyoxyethylene nonylphenyl ether; and (5) a general formula: 10) [Wherein, R ₁₇ is an alkylene bridging group having 1 to 4 carbon atoms, R ₁₈ is an alkylene bridging group having 1 to 3 carbon atoms, R ₁₉ is an alkylene bridging group having 1 to 3 carbon atoms, R ₂₀ is The alkyl group having 1 to 10 carbon atoms and R ₂₁ are an alkyl group having 1 to 10 carbon atoms. q is 2 to 500. At least one compound represented by the formula
A plating method using an acidic copper plating bath containing ０．０１0.01 g / l.