JP2013534276A - Electrolyte and method for depositing a copper-tin alloy layer - Google Patents

Abstract

The present invention relates to electrolytes and methods for depositing brass alloys on consumer goods and industrial articles. In addition to the depositing metal, the electrolyte of the present invention includes additives such as wetting agents, complexing agents and brighteners, in particular sulfur compounds, which have a positive effect on the corresponding method of depositing brass. In the electrolyte of the present invention, the deposited metallic copper and tin or copper, tin and zinc are present in the solution as their ions. Preferred are embodiments in which the metal is used as a salt with an anion that is already present in the electrolyte or does not lead to an increase in the concentration of the anionic component in the electrolyte by further introduction of the corresponding metal salt.

Description

  The present invention relates to electrolytes and methods for depositing brass alloys on consumer goods and industrial articles. In addition to the depositing metal, the electrolyte of the present invention includes additives such as wetting agents, complexing agents and brighteners, in particular sulfur compounds, which have a positive effect on the corresponding method of depositing brass.

  Consumer goods and industrial articles defined in the Consumer Goods Regulations are enhanced with a thin oxidation stable metal layer for decorative reasons and to protect against corrosion. These layers are mechanically stable for long-term use and must not show discoloration or wear phenomena. Since 2001, the sale of consumer goods coated with nickel-containing performance-enhancing alloys has not been approved in Europe according to the EU guidelines 94/27 / EC, and nickel and nickel-containing metal layers are contact allergens, so harsh conditions Only possible under the supervision of Brass alloys, in particular, have become established as an alternative to nickel-containing functional enhancement layers, and mass-produced consumer goods can be used in these ways to produce attractive products that do not contain allergens in electrochemical barrels or racks. In the plating process, the function can be improved at low cost.

  In the manufacture of brass layers in the electronics industry, the solder wettability of the resulting layer and, where appropriate, its mechanical adhesion is an important property of the layer being produced. For use in this field, the appearance of a layer is generally less important than its function. On the other hand, in the production of brass layers in consumer goods, the decorative effect (shine and gloss) and durability of the resulting layer combined with an ideally unchanged appearance are important target parameters.

  Known processes for producing brass layers include conventional processes using cyanide-containing, highly toxic, alkaline baths, as well as two main groups usually found in the prior art, depending on the composition of the electrolyte. There are various electrochemical processes that can be assigned to one, processes using electrolytes based on organic sulfonic acids, or processes using baths based on diphosphoric acid (pyrophosphate).

  For example, Patent Literature 1 describes an electrolyte containing an organic sulfonic acid and tin and copper ions together with a dispersant and a brightener, and optionally an antioxidant.

Patent Document 2 discloses a cyanide-free copper-tin electrolyte based on diphosphate and containing a reaction product of amine and epichlorohydrin in a 1: 1 molar ratio with a cationic surfactant. Is described. The amine can be hexamethylenetetramine. Used for electrodeposition at current densities of 0.5, 1.5, 2.5 and 3.0 A / dm ² .

  Patent Document 3 discloses diphosphorus without cyanide containing an additive composed of an amine derivative, epichlorohydrin and a glycidyl ether compound at a molar ratio of 1: 0.5-2: 0.1-5. It relates to an acid-copper-tin electrolyte. The purpose of this document was to expand the current density range so that uniform metal deposition in the glossy layer can be achieved. It is specified that such deposition can only be achieved when the additive added is made up of all the three components mentioned above.

  Acid brass electrolytes free of cyanide are also known. Such baths often contain one or more alkyl sulfonic acids, usually in combination with additional additives such as wetting agents, complexing agents, brighteners and the like.

  U.S. Patent No. 6,057,031 discloses a process for electrochemical deposition of brass using an acidic electrolyte containing tin and copper ions with an alkyl sulfonic acid and an aromatic nonionic wetting agent.

  Patent Document 5 describes the deposition of brass from an electrolyte containing copper and tin ions together with an alkali sulfonic acid and a wetting agent. It has been proposed there that sulfur compounds can also be advantageously present in the electrolyte. However, it is used in combination with nonionic aromatic wetting agents.

  Patent Document 6 similarly recommends the presence of a specific sulfur compound of the general formula —R—Z—R′— in the acidic brass electrolyte. Its purpose is to equilibrate the standard potential of Cu (II) and Sn (II) by selective complexation of copper. Despite the thio compounds used in this document, the addition of antioxidants is considered essential to prevent the loss of Sn (II) oxidation.

  Depending on the type and nature of the part being coated, different coating processes are commonly used in the electroplating industry. In particular, the process differs with respect to the current density that can be used. There can be essentially three different coating processes.

1. Barrel plating of bulk materials and mass produced parts In this plating process, a relatively low operating current density is used (size: 0.025 to 0.5 A / dm ² ).
2. Rack plating of individual parts In this plating process, a medium operating current density is used (size: 0.2-5 A / dm ² ).
3. High speed plating of strips and wires in a continuous plant In this field, very high operating current densities are used (size: 5-100 A / dm ² ).

  For coating with copper-tin, the first two plating processes (barrel and rack) are very important. Depending on the different types of electrolyte, either barrel plating (relatively low current density) or rack plating (intermediate current density) is possible (see Non-Patent Document 1).

  In view of the prior art described above, particularly for barrel applications, it is likely that the metal is deposited uniformly over the normally considered current density range and does not appear to be too complex in terms of composition, especially for Sn (II) oxidation. In contrast, a deposition process using a stable electrolyte can be judged to be particularly advantageous.

European Patent Application No. 1111097A2 European Patent Application Publication No. 1146148A2 International Publication No. 2004/005528 European Patent Application No. 1408141A1 European Patent Application Publication No. 1874982A1 European Patent No. 1235175B1

“Praktische Galvanotechnik”, Eugen G. Leuze Verlag 1997, page 74ff

  The object of the present invention was therefore to provide a deposition process and further electrolytes which are advantageous from both an ecological and economic point of view compared to the electrolytes disclosed in the prior art. Of particular note is the deposition of an ideal white glossy brass layer in the low current density range due to the electrolyte having a stable and simple composition.

  These objects and further objects not mentioned here, but which can be derived in a manner apparent to a person skilled in the prior art, are for electrolyte and brass deposition according to claims 1 and 10, respectively. This is achieved by a corresponding method. The dependent claims, which respectively refer to claim 1 and claim 10, represent preferred embodiments of the electrolyte or method.

Containing a metal deposited in the form of a water-soluble salt, for example copper, tin and optionally zinc, the following further components:
a) one or more alkyl sulfonic acids;
b) an ionic wetting agent in the form of a sulfonated or sulfated aromatic alkyl aryl ether compound salt;
c) a complexing agent;
d) Proposition of a cyanide-free electrolyte for the deposition of copper-tin brass on consumer goods and industrial articles, characterized in that it comprises a compound selected from the group consisting of dialkylthioether derivatives Surprisingly, it makes it possible to achieve the stated purpose. This electrolyte makes it possible to produce very uniform and very bright copper-tin brass deposits in consumer goods and industrial articles, especially in the low current density range. The electrolyte used has good stability, especially with respect to Sn (IV) precipitates. This quite surprisingly leads to the addition of further antioxidants to the dispensed electrolyte. Thus, in a preferred embodiment, no further antioxidants, especially hydroquinone, catechol, resorcinol, phenol sulfonic acid, cresol sulfonic acid, etc. are present in the electrolyte of the present invention. This would not have been anticipated by those skilled in the art in view of the prior art.

  In the electrolyte of the present invention, the deposited metallic copper and tin or copper, tin and zinc are present in the solution as their ions. Preferred are embodiments in which the metal is used as a salt with an anion that is already present in the electrolyte or does not lead to an increase in the concentration of the anionic component in the electrolyte by further introduction of the corresponding metal salt. Accordingly, they are very preferably water-soluble salts preferably selected from the group consisting of alkyl sulfonates, carbonates, hydroxide carbonates, hydrogen carbonates, hydroxides, oxyhydroxides, oxides or combinations thereof. It is introduced in the form of It can be pointed out that the metal can also be introduced into the electrolyte in the form of a water-soluble anode in a preferred embodiment. In this regard, reference may be made to the method embodiments of the invention which are correspondingly mentioned here as advantages.

  The type and amount of salt introduced into the electrolyte can be a determinant of the color of the resulting decorative brass layer and can be set according to customer requirements. The deposited metal, as shown, is present in an ionic dissolved form in the electrolyte in order to apply a decorative brass layer to consumer goods and industrial articles. The ion concentration of copper can be set in the range of 0.2 to 10 g / l of the electrolyte, preferably 0.3 to 4 g / l of the electrolyte, and the ion concentration of tin is 1.0 to 30 g of the electrolyte. / L, preferably in the range of 2 to 20 g / l of electrolyte, and when present, the ion concentration of zinc is 0.5 to 20 g / l of electrolyte, preferably 1 of the electrolyte. It can be set in the range of ˜3 g / l.

  The electrolyte of the present invention is an acidic electrolyte based on one or more alkyl sulfonic acids. The concentration of acid in the electrolyte can vary from 100 to 300 ml / l of electrolyte, preferably from 150 to 250 ml / l, particularly preferably about 200 ml / l. As the alkyl sulfonic acid in the electrolyte, those that would be conceived by those skilled in the art for this purpose can be used. In this context, the term alkyl refers to a straight-chain or some type of branched alkyl radical having 1 to 10, preferably 1 to 5, particularly preferably 1 to 3 carbon atoms. Particularly preferred is the use of an alkyl sulfonic acid selected from the group consisting of methane sulfonic acid, ethane sulfonic acid and n-propane sulfonic acid. The aforementioned metals that are deposited are advantageously used in the form of water-soluble alkanesulfonate salts. Particularly preferred for improving the performance of consumer goods is that the resulting ion concentrations are 0.3 to 4 grams of copper, 2 to 20 grams of tin and 0 to 3 grams of zinc per liter of electrolyte, respectively. Introducing a metal that deposits as a salt of methanesulfonic acid.

As mentioned above, the electrolyte used contains an ionic wetting / brightening agent. The wetting agent is formed from a salt of a sulfonated or sulfated aromatic alkyl aryl ether compound. Such wetting agents are well known to those skilled in the art ("Die galvanische Abscheidung von Zinn und Zinnlegerungen", Manfred Jordan, Eugen G. Leuze Verlag, Bad Saulgau). The sulfonated or sulfated aromatic alkyl aryl ether compound used contains an alkyl group attached to the aryl radical via an oxygen bridge. For the purposes of the present invention, the term alkyl in the present case contains linear or certain types of branched alkyl radicals having 1 to 10, preferably 1 to 5, particularly preferably 1 to 3 carbon atoms. Refers to a radical. As an aryl radical, one skilled in the art can formulate (C ₇ -C ₁₉ ) -alkylaryl, (C ₆ -C ₁₈ ) -aryl, (C ₇ -C ₁₉ ) -aralkyl, (C ₃ -C ₁₈ ) -heteroaryl. , (C ₄ -C ₁₉ ) -alkylheteroaryl, (C ₄ -C ₁₉ ) -heteroaralkyl can be selected. Particularly preferred are those selected from the group consisting of phenol, naphthol, benzene, toluene, xylene, cumene, anisole, aniline. It is particularly advantageous to use an aryl ethoxylate, in particular an alkyl aryl ether compound selected from the group consisting of β-naphthol ethoxylate, nonylphenol ethoxylate. Sulfonation or sulfation positions can be present in either the aromatic or aliphatic part of the compound. It is preferably present in the aromatic part of the compound. As a counter ion, those skilled in the art can select all cations that would be considered for this purpose. Preference is given to using the alkali metal salts or ammonium ions of the corresponding acids. It is particularly advantageous to select from the group consisting of sodium and potassium. This additive (for example, sodium salt of sulfonated or sulfated aryl ethoxylate, especially Na salt of sulfonated and sulfated alkylphenol ethoxylate) increases the gloss of the deposited layer in the direction of higher current density. Expand the current density range and increase the whiteness of the deposited layer in the combination according to the invention by at least 2 L units. At the same time, this brightener acts as a wetting agent. The mentioned wetting agents are advantageously used at a concentration of 0.01 to 10 ml / l of electrolyte, preferably 0.2 to 5 ml / l of electrolyte, particularly preferably 0.5 to 1 ml / l of electrolyte.

A complexing agent must also be present in the electrolyte. The complexing agent has a role in particular preventing Sn (IV) ions from precipitating as tin dioxide. Without the complexing agent added, the electrolyte becomes turbid in a short time due to the tin dioxide formed. As a result, brass deposits are increasingly matte. Turbidity due to finely ground SnO ₂ greatly increases the consumption of other organic additives. The addition of complexing agent greatly reduces the degree of turbidity of the electrolyte, the quality of the brass layer remains consistently good (glossy and white), increases the use of the bath and minimizes the consumption of organic additives become.

  As complexing agents, those skilled in the art can select compounds that would be considered for this purpose. Preferred compounds are those based on (hydroxy) dicarboxylic or tricarboxylic acids. Particularly preferred is the use of a complexing agent selected from the group consisting of oxalic acid, malonic acid, succinic acid, tartaric acid, malic acid, citric acid, maleic acid, glutaric acid and adipic acid. Particularly preferred in this regard is malic acid. The complexing agents mentioned are advantageously used at concentrations of 1 to 300 g / l of electrolyte, preferably 20 to 200 g / l of electrolyte, particularly preferably 50 to 150 g / l of electrolyte.

  As mentioned above, the electrolyte of the present invention is also mixed with one or more dialkylthioether derivatives. These solvents lead to improved deposition of brass alloys, especially in the low current density range. Symmetrically substituted dialkylthioether derivatives such as thiodiglycol propoxylate or thiodiglycol ethoxylate are preferred in this regard. As the alkyl radical, those described above can also be used in this case. The alkyl radical may be further substituted with a functional group. The latter can preferably be selected from the group consisting of hydroxy, carboxylic acid (ester), thiol, amino. Particularly preferred in this regard are, for example, thiodiglycol propoxylate, thiodiglycol, thiodiglycerol, thiodiglycol ethoxylate, thiodiethylenebis (3- (3,5-di-tert-butyl-4-hydroxy Phenyl) propionate), 2-amino-4- (methylthio) butanoic acid, 2,2'-thiodiethanethiol, 3,3'-thiodipropanethiol, 2,2'-thiodiacetic acid, 3,3'- Thiodipropionic acid, diethyl 2,2'-thiodiacetate, dimethyl 2,2'-thiodiacetate, dioctyl 2,2'-thiodiacetate, didodecyl 2,2'-thiodiacetate, didodecyl 3,3 ' -Thiodipropionate, dimethyl 3,3'-thiodipropionate, diethyl 3,3'-thiodipropionate , Dioctyl 3,3′-thiodipropionate, 3,3′-thiodipropanol, 2,2′-thiodiethanol, 4,4′-thiodibutanol, 1,1 ′-(thiodi-2,1- Ethanediyl) 2-propionate, a compound selected from the group consisting of dioctadecyl 3,3′-thiodipropionate, and 2-amino-4- (methylthio) butanoic acid is considered highly preferred.

  The aforementioned dialkyl thioether derivatives are advantageously used at a concentration of 0.01 to 20 g / l of electrolyte, preferably 0.1 to 5 g / l of electrolyte, particularly preferably 0.3 to 1 g / l of electrolyte. .

  The pH of the electrolyte is in the strong acid range due to the addition of acid. The pH is set to be in the range of −1 to 4, preferably in the range of −0.5 to 2, particularly preferably about 1.

  Furthermore, the present invention proposes an electrolyte deposition method for applying a brass alloy layer to consumer goods and industrial articles, wherein the substrate to be coated is immersed in the electrolyte according to the present invention and the appropriate current flow. Is given. The preferred embodiment of the electrolyte described above applies equally to the method shown here.

The electrolyte is preferably heated to a temperature in the range of 20-40 ° C, preferably 30 ° C. The current density can be set in the range of 0.01 to 100 amps [A / dm ² ] per square decimeter, depending on the type of plating equipment. Thus, in barrel plating process, preferably a current density in the range of 0.01~0.75A / dm ^2, more preferably 0.025~0.5A / dm ^2, about 0.1～0.3A / dm ² is particularly preferred. In the rack plating process, it is in the range of 0.2-10.0 A / dm ² , particularly preferably 0.2-5.0 A / dm ² , very particularly preferably 0.25-1.0 A / dm ² . The current density is preferably selected. However, barrel applications (see “Introduction to“ Practische Galvanotechnik ”, Eugen G. Leuze Verlag 1997, page 74ff”) are preferred.

  Various anodes can be used when using the electrolyte of the present invention. A soluble anode is particularly advantageous. The soluble anode is preferably an anode made of a material selected from the group consisting of electrolytic copper, phosphorus-containing copper, tin, copper-tin alloy, copper-zinc alloy, and copper-tin-zinc alloy. Particularly preferred is a combination of different soluble anodes composed of these materials.

  A pure copper anode can also be used for this electrolyte system. However, preferred anodes of copper-tin electrolytes based on alkyl sulfonic acids are copper-tin alloys having a copper content of <90 wt% to> 50 wt% and a tin content of> 10 wt% to <50 wt%. is there. The anode more preferably contains 85-60 wt% copper and 40-15 wt% tin. The copper content of the anode is more preferably about 4 times the tin content. This is also true when other elements such as zinc are optionally present in the soluble anode.

  The electrolyte also does not contain any material that is harmful to health, which is even more advantageous than other copper-tin electrolyte systems based on methanesulfonic acid. In the copper methanesulfonate-tin electrolyte, in particular, an antioxidant is usually used to prevent oxidation of tin. As the antioxidant, hydroquinone (carcinogenicity), catechol and resorcinol (both are harmful to health) are often used. None of the chemicals mentioned are used in the electrolyte system of the present invention. Furthermore, the electrolyte is stable enough to make without the addition of an antioxidant.

In the present _{invention, (C} 6 _{~C 18)} - aryl is completely aromatic made of 6 to 18 carbon atoms. In particular, such a system is selected from the group consisting of phenyl, naphthyl, anthracenyl and the like.

A (C ₇ -C ₁₉ ) -alkylaryl radical is a radical containing a (C ₁ -C ₈ ) -alkyl radical in a (C ₆ -C ₁₈ ) -aryl radical.

A (C ₇ -C ₁₉ ) -aralkyl radical is a radical having a (C ₆ -C ₁₈ ) -aryl radical in a (C ₁ -C ₈ ) -alkyl radical. Here, the radical is bound to the molecule concerned.

For the purposes of the present invention, _(C 3 ~C 18) _- heteroaryl radicals are aromatic system having at least 3 carbon atoms. Additional heteroatoms are further present in the aromatic system. These are preferably nitrogen and / or sulfur. Such heteroaromatics are described, for example, by Bayer-Walter, Lehrbuch der Organischen Chemie, S .; It will be in Hirzel Verlag, 22nd edition, page 703ff.

For the purposes of the present invention, (C ₄ -C ₁₉ ) -alkylheteroaryl is a (C ₃ -C ₁₈ ) -heteroaryl radical supplemented by a (C ₁ -C ₈ ) -alkyl substituent. The bond to the molecule concerned is via a heteroaromatic.

On the other hand, (C ₄ -C ₁₉ ) -heteroaralkyl is a (C ₃ -C ₁₈ ) -heteroaryl radical attached to the molecule concerned via a (C ₁ -C ₈ ) -alkyl substituent.

Electrolyte formulation according to the present invention:
180 ml / l methanesulfonic acid (70%)
60 g / l malic acid 20 ml / l copper methanesulfonate solution (100 g / l) = 2 g / l Cu in electrolyte
20 ml / l tin methanesulfonate solution (300 g / l) = 6 g / l Sn in electrolyte
1 g / l 2-amino-4- (methylthio) butanoic acid 1 ml / l brightener (sodium salt of sulfonated and sulfated alkylphenol ethoxylate)
1. Place 200 ml / l deionized water into a 1 liter glass beaker.
2. Next, 180 ml / l methanesulfonic acid (70%) is added slowly with vigorous stirring.
3. Next, 60 g / l malic acid is dissolved in dilute methanesulfonic acid with vigorous stirring. After complete dissolution,
4. Add 20 ml / l copper methanesulfonate solution and 20 ml / l tin methanesulfonate solution and bring the volume to 950 ml with deionized water.
5. Next, 1 g / l of 2-amino-4- (methylthio) butanoic acid is added. After completely dissolving this,
6.1 ml / l brightener is added to the electrolyte and the electrolyte is brought to final volume (1000 ml) with deionized water.

Deposition parameters:
Temperature: Electrolyte temperature: 30 ° C
pH: pH <1
Current density for barrel applications:
The best current density for barrel applications are 0.1~0.3A / dm ^2.
anode:
The anode of the copper-tin electrolyte based on methanesulfonic acid is a copper-tin alloy anode with a copper content of 80% by weight and a tin content of 20% by weight [commercially available from Goodfell GmbH].

Electrolyte characteristics:

Coating characteristics:
Coating: Copper-tin alloy Composition: 70-55% copper, 30-45% Sn (depending on operating conditions)
Coating density: about 8.2 g / cm ³ (calculated)
Color: white, L ^* value of about 82-85 at 0.1 A / dm ²

Experiments with alternatives to dialkylthioether derivatives:
Formulating 1 l electrolyte:
Experimental reference operating parameters using 2-amino-4- (methylthio) butanoic acid:
Temperature: 30 ° C
Anode: Cu-Sn80 / 20
Was brass plate experiments deposition 0.5 dm ² with 1 liter mobile 0.2 A / ^dm 2/10 min Glass beakers / 200 rpm / 6 cm magnetic stirrer bar / article and 0.5A / ^dm 2/5 min.
The dialkylthioether derivatives were replaced with the following substances (see table) in these experiments.

Claims (14)

A cyanide-free electrolyte for the deposition of copper-tin-brass on consumer goods and industrial articles containing a metal deposited in the form of a water-soluble salt, comprising the following further components:
a) one or more alkyl sulfonic acids;
b) an ionic wetting agent in the form of a sulfonated or sulfated aromatic alkyl aryl ether compound;
c) a complexing agent;
d) an electrolyte comprising a compound selected from the group consisting of dialkylthioether derivatives.   2. The electrolyte according to claim 1, wherein the deposited metal includes copper and tin or copper, tin and zinc.   The deposited metal is present in an ionically dissolved form, the copper ion concentration is in the range of 0.2 to 10 g / l of the electrolyte, and the tin ion concentration is 1.0 to 20 g / l of the electrolyte. 3. Electrolyte according to claim 1 or 2, characterized in that the concentration of zinc, if present, has an ion concentration of zinc in the range of 1.0 to 20 g / l of electrolyte.   The electrolyte according to any one of claims 1 to 3, wherein the alkylsulfonic acid selected from the group consisting of methanesulfonic acid, ethanesulfonic acid, and n-propanesulfonic acid is used.   The electrolyte according to claim 1, wherein the deposited metal alkanesulfonate is used as a water-soluble salt.   The electrolyte according to any one of claims 1 to 5, wherein an alkylaryl ether compound selected from the group consisting of β-naphthol ethoxylate and nonylphenol ethoxylate is used.   The electrolyte according to any one of claims 1 to 6, wherein an alkali metal salt of a corresponding acid is used.   8. A complexing agent selected from the group consisting of oxalic acid, malonic acid, succinic acid, tartaric acid, malic acid, citric acid, maleic acid, glutaric acid, and adipic acid is used. The electrolyte according to one item.   Thiodiglycol propoxylate, thiodiglycol, thiodiglycerol, thiodiglycol ethoxylate, thiodiethylenebis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), 2-amino-4 -(Methylthio) butanoic acid, 2,2'-thiodiethanethiol, 3,3'-thiodipropanethiol, 2,2'-thiodiacetic acid, 3,3'-thiodipropionic acid, diethyl 2,2 ' -Thiodiacetate, dimethyl 2,2'-thiodiacetate, dioctyl 2,2'-thiodiacetate, didodecyl 2,2'-thiodiacetate, didodecyl 3,3'-thiodipropionate, dimethyl 3,3 '-Thiodipropionate, diethyl 3,3'-thiodipropionate, dioctyl 3,3'-thiodipropionate 3,3'-thiodipropanol, 2,2'-thiodiethanol, 4,4'-thiodibutanol, 1,1 '-(thiodi-2,1-ethanediyl) 2-propionate, dioctadecyl 3, The electrolyte according to claim 1, wherein a dialkylthioether derivative selected from the group consisting of 3′-thiodipropionate is used.   The electrolyte according to any one of claims 1 to 9, wherein the electrolyte has a pH in a range of -1 to 4.   Electrochemically deposit copper-tin-brass on consumer goods and industrial articles containing metals deposited in the form of water-soluble salts, dipping the substrate to be coated into an electrolyte and providing appropriate current flow It is a method, Comprising: The method using the electrolyte as described in any one of Claims 1-10 characterized by the above-mentioned.   The method of claim 11, wherein the electrolyte is heated to a temperature in the range of 20-40 ° C. during the deposition of the metal.   13. A method according to claim 11 or 12, characterized in that the current density is set in the range of 0.01 to 100 amperes per square decimeter.   Using a soluble anode composed of a material selected from the group consisting of electrolytic copper, phosphorus-containing copper, tin, copper-tin alloy, copper-zinc alloy and copper-tin-zinc alloy or combinations of these anodes The method according to any one of claims 11 to 13.