JPS609891A - Copper electrodeposition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The method of the present invention relates in a broad sense to a method of electrodepositing a copper film on a conductive substrate, and more specifically, the method of the present invention relates to a method of electrodepositing a copper film on a conductive substrate. Electroplating of Cylinders 8 - Concerning a method for providing an engineering copper plating film which is highly suitable for subsequent mechanical engraving.

[Conventional technology]

In the past, various copper plating bath compositions and methods have been employed to deposit a copper plating film on the surface of a rotogravure cylinder at a thickness sufficient to permit subsequent engraving. The copper plating baths used to deposit bright decorative copper platings produce smooth, ductile copper platings, but the self-annealing nature of the deposited copper film results in significant softening of the film after the plating process. 1. Like using a diamond stylus. The drawback is that it results in a coating that is unsuitable for mechanical engraving. Alternatively, non-self-annealing copper plating baths have been used;
Such copper plating has a cloudy, dull appearance and poor smoothness and must be mechanically polished to provide a surface finish suitable for subsequent engraving.

[Problem that the invention seeks to solve]

[Structure of the Invention] [Means for Solving the Problems] The benefits and advantages of the present invention are such that under certain operating conditions, the benefits and advantages of the present invention are extremely An engineering steel coating can be produced that is smooth, ductile, bright, and of substantially uniform hardness; the copper coating is not self-annealing and can be used for long periods of time following the plating process. It is based on the discovery of the fact that the copper plating can be engraved by mechanical engraving or otherwise in order to preserve its hardness.

This copper plating bath contains a copper component in an amount sufficient to deposit copper on the substrate, and a certain amount of a bath-soluble/compatible organic brightener including the following (1), (21) and (3). (1) organic polyether compounds and mixtures thereof; (2) organic sulfide compounds and mixtures thereof; and (3) the following (A), ( At least one compound selected from each of the group consisting of B) and (G): (
A) A compound roughly corresponding to the following general formula A.

(B) Substituted phthalocyanine 11 corresponding to the following general formula B
- compound.

Pc-(X) General formula B (G) Alkylated polyethyleneimine reaction product having a quaternary nitrogen atom and: (A) , (B) and (
(3) mixture.

12- The organic brightener in the aqueous/acidic plating bath has a polyether compound concentration in the range of about 0.00f to about 511/l;
Organic sulfide compound concentration is about 0.0005 to about 111/L
, and a group as a mixture of three or more (3
) in an amount such that the brightener concentration is at least about 25 W/l and less than or equal to about 0.5 F/l.

In the proposed method of the present invention, the aqueous acidic copper plating bath is used at a temperature of about 60° to about 100°C (16-38°C) and a cathode current density of at least about 6OASF (6,4A/D
mi) and approximately 300 ASF (32A/Dm
) or less than or equal to at least about 0.00
A 1 inch (0.025α) thick engineering grade copper coating is deposited. Approximately 6OASF (6,4k/Dtr?) using matched anodes or multiple anodes.
) to prevent low current density regions from occurring, which further ensures that a substantially uniform thickness of copper is deposited on the substrate.

[Description of preferred embodiments]

To practice the method of the invention, typically from about 180 to
About 2501! /l copper sulfate, and about 30 to about 80 g/l
Prepare a sulfate type aqueous/acid plating bath containing sulfuric acid. Alternatively, a fluoroborate type bath may be prepared, typically containing about 200 to about 600 g/l of silver fluoroborate and about 6097 g/l of fluoroboric acid. The bath may also be acidified with an equivalent amount of phosphoric acid, nitric acid, sulfamic acid or sulfuric acid using copper nitrate or copper sulfamate salt in about an equivalent proportion to copper sulfate. In a preferred embodiment of the invention, a sulfate type copper bath was used.

The aqueous plating bath may further contain halogen ions, such as chlorine and/or bromide ions, in amounts up to about 0.297. A halogen ion concentration of 0.2 EI/or more is not preferable because the ductility of the copper-plated film decreases in some cases.

The unique property of not self-annealing while having the desired favorable film physical properties is achieved by using a special combination of organic brighteners of the type described above. Preferred organic polyether compounds have at least 4 etheric oxygen atoms and an average molecular weight of about 18
0 to 1,000,000 bath-soluble and compatible polyethers. Polypropylene glycol and polyethylene glycol and average molecular weight of about 600 to about 6,000
A mixture of these aromatic alcohol alkoxylates having an average molecular weight of about 300 to 2,500 and an average molecular weight of about 10
Particularly satisfactory results are obtained with alkoxylates of amines ranging from 0.00 to about 50.000. Examples of satisfactory polyether luster compounds include: polyethylene glycols having an average molecular weight of about 400 to about 1,000,000; naphthol ethoxylates containing from 5 to 45 moles of ethylene oxide groups; naphthol propoxylates containing from 5 to 15 moles of propylene oxide groups. ; tr-nonylphenol ethoxylate containing 5 to 30 moles of ethylene oxide group; propylene glycol having an average molecular weight of about 350 to about 1,000; block polymer of polyoxyethylene/polyoxypropylene glycol having an average molecular weight of about 350 to 250,000; ethylene oxide group Phenol ethoxylates containing from 5 to 100 moles; Phenol propoxylates containing from 5 to 15 moles of propylene oxide groups and having an average molecular weight of about 1
600 to about 30,000 ethylenediamine block polymers. Other polyether compounds include those disclosed in U.S. Pat. No. 4,272,335,
＼ These are also useful.

The amount of polyether brightener used is about 0.001 to about 5
11/l, and the higher the molecular weight, the lower the concentration is generally used.

Organic sulfide brightening compound (2) effective for use in the bath of the present invention
Various organosulfide sulfonic acid compounds such as those described in U.S. Pat. No. 3,267,010, particularly those listed in Table 1 of that specification; U.S. Pat.
Included are organic sulfur compounds such as those listed in Table 1 of the '582 publication; and organic polysulfide compounds as listed in Table 1 of US Pat. No. 3,328,273.

Organic sulfide compounds having sulfonic or phosphonic groups may also contain in their molecules, especially their aromatic and heterocyclic sulfides.
Various substituents may be included on the sulfonic acid or phosphonic acid such as methyl, chloro, bromo, methoxy, ethoxy, carboxy or hydroxy. These compounds are used in the form of free acids, alkali metal salts, organic amine salts or other forms.

Other suitable organic divalent sulfur compounds include HO, P-(C
tH2)3-8-8-(OH,)3-PO,H, as well as mercaptans, thiocarbamates, thiol carbamates, thiozensates and thiocarbonates having at least one sulfonic or phosphonic group.

A particularly preferred group of organic divalent sulfur compounds described in U.S. Pat. , So, H or PO3H, n is about 2~
It is an organic polysulfide compound represented by the number 5]. These organic divalent sulfur compounds contain at least two divalent sulfur compounds.
It is an aliphatic polysulfide having adjacent valent sulfur atoms and one or two terminal sulfonic acid groups or phosphonic acid groups in the molecule. The alkylene portion of the molecule may be substituted with methyl, ethyl, chloro, bromo, ethoxy, hydroxy, and other groups. These compounds can be added as free acids or alkali metal or amine salts.

The organic sulfide brightening compound or mixture thereof is included in the bath at a concentration ranging from about 0.0005 to about I El/l.

In addition to the brighteners consisting of the polyether compound (11) and the sulfide compound (2), this plating bath also contains as essential brighteners at least three brightening compounds consisting of the compounds (A), (B) and (G). (3). Gloss compounds (A) corresponding to general formula A are typically those described in U.S. Pat. Representative agents include diethylsafranine azodimethylaniline - Janus G
re-en B, ') Ethyl safranin azophenol = Ja-nus Black, Safranin azonaphthol - Janus Blue, Janus Gray (
C1olor Index 137.5ociety
of Dyers & Colourists, by
F. M. Rowe, (1924)), dimethylsafranine, azodimethylaniline, phenosafranine, Fu
chsia, Amethyst violet and others.

Brighteners corresponding to general formula B consist of substituted phthalocyanine groups, which may be metal-free or are divalent or trivalent stable groups linked by coordination of the isoindole nitrogen atoms in the molecule. It may contain a metal selected from cobalt, nickel, chromium, iron or copper, and mixtures thereof,
Among these, copper is a typical preferred metal.

Such phthalocyanine compounds suitable for use in the practice of the present invention have a bath solubility of at least about 0.1119/L and less than about 0.5 g/L, preferably from about 25 to about 5 On9/L. Used in l. Suitable phthalocyanine compounds conform to the following structural formula: (X)bΦ-1,''=, so-Ico(X)bN-<z)a-food(X).

8'191 Substituted phthalocyanine compounds suitable for use in the practice of the present invention further include U.S. Pat.
The disclosure in Publication No. 5 is included. A particularly preferred phthalocyanine compound is Alcian blue (Alcian blue).
Blue).

The organic luster compound (Ci) is a reaction product of polyethyleneimine and an organic compound that alkylates the nitrogen of the polyethyleneimine to produce quaternary nitrogen.

Such compounds that can be used in the practice of this invention are disclosed in US Pat. No. 3,770,598. The alkylating agents are either saturated or unsaturated aliphatic and aromatic compounds. Compounds that have been found to be particularly useful are aralkyl halides, halo(X).

Organic compounds containing active halogens such as alkyl halides, alkenyl halides and alkynyl hyhalides, acid halides, acyl halides, and the like.

In addition, alkyl sulfates, alkyl sultones, aldehydes, ketones, isocyanates, thioisocyanates, epoxides, acylamides, acids, acid anhydrides, urea, cyanamide, guanidine, and others can be used. In some cases organic compounds may also be used in which the reactive group is not attached to the alkyl chain, but rather directly to the aromatic nucleus. An example of such an organic material is 2,4-dinitrochlorobenzene, which reacts with either the primary or secondary nitrogen of the polyethyleneimine and/or quaternizes the tertiary nitrogen. Therefore, the term "alkylation" of the nitrogen of polyethyleneimine includes cases where the nitrogen is bonded directly to an aryl or aromatic nucleus as well as cases where the nitrogen is bonded to an aliphatic group. It means.

Compounds which have been found to give particularly good results are benzyl chloride, allyl bromide, dimethyl sulfate and propane sultone. However, these compounds are only examples of organic compounds that can alkylate the nitrogen of polyethyleneimine. Preferably, the alkylating agent is an aromatic halide.

When alkylating agents react with primary or secondary amines,
They change to secondary amines and tertiary amines, respectively. When alkylation occurs on the -class and/or secondary nitrogen, elimination of the alkylated groups of the organic compound -H, ie, halogens, sulfates, etc., occurs. However, in the case of tertiary nitrogens, quaternization occurs to form quaternary salts.

Even if only about 5 atoms of the nitrogen atoms are quaternized, good results are still obtained, 10 atoms are more preferable, and 20 atoms are even better, but if as many nitrogen atoms as possible in the polyethyleneimine brightener are quaternized, good results are obtained. Preferably, it is graded.

The polyethyleneimine used to form the gloss additive can have a wide range of molecular weights. Typically around 300
of molecular weight in the range of ~several million. However, in many cases it is preferred that the molecular weight is within the range of about 300 to 1.000,000. This organic luster compound (0)
is about 0.59/or less, preferably about 35 to about 1 oow
It is best to use the amount of /L.

organic brighteners (A), (B) and (0) in combination of at least three, at least about 25 TR9/l;
It is used in an amount of about 30 to 90 q/l.

In carrying out the present invention, a conductive substrate is immersed as a cathode in a bath having the above composition, and electricity is applied until a desired thickness of copper is deposited. During the plating operation, the bath temperature is about 600 to about 100"
'F (16-38°C), preferably about 70'F to about 90'F (21-32°C). 100″F (3
If the temperature exceeds 8°C, a copper film with low ductility tends to be formed in many cases, which is not preferable.

This copper electrodeposition is at least about 60 ASF (6,4A
/Dze) with a current density of approximately 30OASF (32A
/Dze), and in special cases 300 ASF (32
A/Da) or higher current density. Preferred cathode current densities are from about 100 to about 20 OASF (11-22
A/Dze). In order to deposit a substantially uniform thickness of copper on the substrate, the arrangement of the anodes is designed to provide a uniform current density over substantially the entire surface of the cathode. For this purpose, a matched anode or a plurality of anodes are spaced apart to provide a substantially uniform cathode current density, as is conventionally used in rotogravure cylinder plating.

The unique copper plating deposited by the practice of the present invention is bright, smooth, ductile, and consists of substantially pure copper, and can be used in electroforming, audio and piteo disc manufacturing, rotogravure cylinders, and various other engineering applications. It is eminently suitable for various applications. Other properties of this copper plating include a relatively uniform hardness, typically a Diamond Pyramid hardness number of 200 or higher at a 100 gram load, a highly homogeneous, coaxial crystal structure, and a grain It has the feature that the diameter is approximately 1 micron or less. Engineering copper coatings made in accordance with the present invention have a coating thickness of at least about 0.001 inch (Q, 0025c).
m) to about 0.050 inches (0.127 mm) or more, and is significantly different from ordinary decorative copper plating in that it has the unique property of not having self-animation properties. It's different.

The method of the present invention is not suitable for the purpose of producing so-called decorative steel platings since dark streaks occur in all low current density regions, such as average cathode current densities below 60 ASF (6,4 A/D). is not applicable.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.
The invention is not limited to these examples unless it departs from the gist of the invention.

Example 1 Copper sulfate pentahydrate approximately 1959/l, sulfuric acid 759/l, chlorine ion approximately 20 to approximately 10 (119/4 and approximately 120/l)
brightener (1) consisting of about 21,111 fT/l of polypropylene oxide (molecular weight 750); brightener (2) consisting of about 21111 fT/l of bis(3-sulfoprobyl disulfide, 2Na salt);
, a brightener (3) corresponding to the general formula (A) consisting of JanuS Green B of about 15ψ′t, Met of about 15μ/l
A brightening agent (3) corresponding to the general formula (B) consisting of hic Turquoise and a brightening agent (3) corresponding to the general formula (C) consisting of polyethyleneimine of about 12 Ta/L quaternized with penzyl chloride. An aqueous and acidic steel plating bath containing a combination of organic brighteners was prepared.

The rotogravure cylinder was immersed in the bath and surrounded by a matched copper anode, with the bath temperature controlled at about 80'F (27C);
Approximately 15OASF (16A/Drr.
? ) so that the current density becomes [Also.

It was observed that the produced copper plating film was completely bright, had good smoothness and ductility, and had a substantially uniform hardness of 200 on the diamond hardness number (DPI) or higher at a load of 100 grams. The copper coating was substantially non-self-annealing as evidenced by the fact that there was no noticeable decrease in hardness even after standing for 48 hours after the copper plating was deposited.

Example 2 About 195 g/l copper sulfate pentahydrate, 75 g/l sulfuric acid, about 20 to about 100 m/l chloride ions and about 60 m
Brightener (1) consisting of polyethylene oxide (molecular weight 3350) of y/l, brightener (2) consisting of bis(3-sulfoprobyl disulfide/2Na salt) of about 30 my/l
, a brightener (3) corresponding to the general formula (A) consisting of about 10 om/l of Janus Green B, 1 om9/l of Methia Turquoise corresponding to the general formula (B) and polyethyleneimine quaternized with benzyl chloride. An aqueous acidic steel plating bath was prepared containing a combination of organic brighteners consisting of a brightener (3) corresponding to the general formula (C) K.

The bath temperature was controlled at approximately 75'F (24°C) and the rotogravure cylinder was immersed in the bath and surrounded by a matched copper anode for 300 r.
While rotating the cylinder at pm, current was applied to the work piece as a cathode to obtain a current density of about 10 OASF (1, OA/D).

The produced copper plating film was completely bright, had good smoothness and ductility, and had a hardness of about 200 DPI or more at a load of 100 grams. This copper plating film was substantially non-self-annealing.

Example 3 About 1959/l of steel sulfate pentahydrate, 75 g/l of sulfuric acid, 27- about 20 to about 100 m9/l of chloride ions and about 120
Polypropylene oxide (molecular weight 750)
A brightener consisting of (+1, approximately 30 my/L of a brightener consisting of bis(3-sulfoprobyl disulfide, 2Na salt) (2
), and a brightener (3) corresponding to general formula (A) consisting of about 8 #/l of Janus Green B, about 22 #/l of M
General formula (B) consisting of ethical Turquoise
Aqueous/acidic steel plating containing a combination of an organic brightener consisting of a brightener (3) corresponding to the formula (3) and a brightener (3) corresponding to the general formula (C) consisting of polyethyleneimine quaternized with benzyl chloride. A bath was prepared.

The bath temperature was controlled at approximately 70°C (21°C), the rotogravure cylinder was immersed in the bath and surrounded by a matched copper anode, and the rotogravure cylinder was heated at 150 rpm.
While rotating the cylinder at m.m, current was applied to the work piece as a cathode to achieve a current density of about 150 ASF (16 A/Da').

The produced copper plating film is completely bright, has good smoothness and ductility, and has a DPI of about 200 (DPI) at a load of 100 grams.
It had a hardness of This copper plating film was substantially non-self-annealing.

28- Since it is clear that widely different embodiments may be constructed without departing from the spirit and scope of the invention, this invention is not limited to the specific embodiments thereof, except as limited to the claims below. There are no restrictions.

Claims (1)

[Claims] (1) An engineering copper plating film that is extremely smooth, ductile, shiny, has substantially uniform hardness, and exhibits non-self-annealing properties on a conductive substrate. A method of electrodeposition, comprising a copper component in an amount sufficient to deposit copper on a substrate, (1) an organic polyether compound and a mixture thereof; (2) an organic sulfide compound and a mixture thereof; and (3) At least one compound selected from each of the group consisting of the following (A), (B) and (Ct) =
(A) Compounds generally falling under the following general 2A. (B) A substituted phthalocyanine compound corresponding to the following general 2B. General formula B Pc-(X). (C) an alkylated polyethyleneimine reaction product having a quaternary nitrogen atom; and a mixture of (A), (B) and (C); and certain combinations of bath-soluble and compatible organic brighteners, including: a step of preparing an aqueous/acidic solution for
A conductive substrate as a cathode is immersed in the solution and current is passed through the solution at an average cathode current density of at least 60 ASF (6,4 A/Di) to a film thickness of at least 0.001 inch (0,0025 cm). A method consisting of the step of electrodepositing engineering copper plating on the substrate until it is coated. (2) A method according to claim 1, characterized in that the brightener (11) is present in an amount of 0.001 to 51!/l. (3) The brightener (2) is present in an amount of 0.001 to 51!/l. A method according to claim 1, characterized in that the brightener (3) is present in an amount of at least 25 g/l-0,
Process according to claim 1, characterized in that it is present in an amount of 5 El/l. 5. Process according to claim 1, characterized in that the brightener (3) is present in an amount of 30 to 90 o/l. (6) A patent claim further comprising the step of controlling the temperature of the aqueous/acidic solution within the range of 60° to 100″T' (16 to 38°C) during electrodeposition of copper plating. The method according to item 1. 3- (During the electrodeposition of copper plating, the temperature of the aqueous/acidic solution is further controlled within the range of 70° to 90° C. (21° C. to 32° C.). The method according to claim 1, characterized in that the step of electrodeposition of copper plating on the substrate has an average current density of 3.
The method according to claim 1, characterized in that it is carried out at less than 00 ASF (32 A/Dm'). (9) The copper plating electrodeposition process on the substrate has an average current density of 1
The method according to claim 1, characterized in that it is carried out at 00-200 ASF (11-22 A/Di). (II) The method according to claim 1, characterized in that the aqueous/acidic solution further contains halogen ions of 0.29% or less. θυ of the anode immersed in the solution. Adjust the relative position to the base material to 60 to 300 ASF (6,
4. The method of claim 1, further comprising the step of providing a substantially uniform cathode current density within the range of 4 to 32 A/Di. 4-(I2) consisting of a rotogravure cylinder in which the conductive substrate is immersed in the solution, and during the electrodeposition step of the copper plating, the conductive substrate is The method of claim 1, further comprising the step of rotating the cylinder.a3 The cylinder is extremely smooth, ductile, shiny, has a substantially uniform hardness, and A method for electrodepositing an engineering copper plating film exhibiting non-self-annealing properties on a conductive substrate, comprising: a copper component in an amount sufficient to deposit copper on the substrate; and (1) an organic polyether compound. and mixtures thereof; (2) organic sulfide compounds and mixtures thereof; and (3) at least one compound selected from each of the group consisting of the following (A), (B), and (0): (
A) Compounds that generally fall under the following general 2A. (B) A substituted phthalocyanine compound corresponding to the following general formula B. Pc-(X)n general formula B (0) alkylated polyethyleneimine reaction product having a quaternary nitrogen atom and a mixture of (A), (B) and (0); preparing an aqueous acidic solution containing a combination of brighteners;
immersing a conductive substrate as a cathode in said solution and passing current through said solution at a 7-average cathode current density of at least 60 ASF (6,4 A/D);
an engineering copper plating film produced using a method comprising electrodepositing an engineering copper plating onto the substrate to a film thickness of at least 0.001 inch (0,0025 儂), A copper plating film of uniform hardness that is bright, smooth, ductile, substantially non-self-annealing, and made of substantially pure copper. (14) Comprised of substantially pure copper that is lustrous, smooth, ductile, substantially non-self-annealing, and has a crystalline structure with an average grain size of approximately 1 micron or less that is highly uniform, homogeneous, and coaxial. An engineering steel plating film, further characterized in that the crystal structure is stable without a tendency to recrystallize after electrodeposition.