JPS6112037B2 - - Google Patents

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. This invention relates to a method for electroplating cylinders, providing an engineering copper plating film that 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 bath used to deposit bright decorative copper plating is
It produces a smooth and ductile copper plating, but since the deposited copper film is self-annealing, the film softens significantly after the plating process, making it difficult to use for mechanical engraving, such as with a diamond stylus. However, it has the disadvantage of forming an unsuitable film. Alternatively, non-self-annealing copper plating baths have been used, but such copper plating has a dull, matte appearance and poor smoothness and must be mechanically polished for further processing. The surface needs to be finished to make it suitable for engraving.

[Means for solving problems]

The benefits and advantages of this invention are that the use of an aqueous acidic copper plating bath of certain compositions provides a very smooth, ductile, bright and substantially uniform coating under certain operating conditions. It is possible to produce a hard engineering copper plating film, which does not have self-annealing properties and can be processed by mechanical engraving or other means to maintain its hardness for a long period of time following the plating process. It is based on the discovery of the fact that copper plating can be engraved.

This copper plating bath consists of a copper component in an amount sufficient to deposit copper on the substrate, and a certain combination of bath-soluble and compatible organic brighteners consisting of the following (a), (b), and (c). It consists of an acidic aqueous solution containing the following ingredients.

(a) at least one organic polyether compound, (b) at least one organic sulfide compound, and (c) general formula (A) [wherein R ₁ and R ₂ are groups selected from the group consisting of hydrogen, methyl and ethyl groups, and X is selected from the group consisting of base, bromine, iodine, fluorine, sulfuric acid, bisulfuric acid and nitrate ions Anion, Y is H, _-NH2 , -N( _CH3 ) ₂ and -N=N-Z, Z
is an aromatic group selected from the group consisting of phenyl, naphthyl, and phenyl and naphthyl groups substituted with amino groups, alkyl-substituted amino groups, hydroxy and alkoxy substituents] Compound: General formula (B) Pc-(X) _o (B) [In the formula, Pc is phthalocyanine; X is _-SO2NR2 , _-SO3M , _-CH2SC ( _{NR2 ) 2} +Y-; R is H, alkyl having 1 to 6 carbon atoms, 6 carbon atoms
Aryl, aralkyl having 6 carbon atoms in the aryl position and 1 to 6 carbon atoms in the alkyl position, heteroartic rings having 2 to 5 carbon atoms and containing at least one nitrogen, oxygen, sulfur or phosphorus atom, and 1 to 5 carbon atoms alkyl, aryl, aralkyl and heteroaromatic groups as described above containing amino, hydroxyl, sulfonic or phosphonic groups; n is 1 to 6; Y is hydrogen and alkyl sulfate containing 1 to 4 carbon atoms in the alkyl position; M is H, Li, Na, K or Mg; and at least one phthalocyanine derivative having a quaternary nitrogen atom;
Seed Alkylated Polyethyleneimine Reaction Products
(C).

The organic brightener in this aqueous/acidic plating bath has a polyether compound concentration in the range of about 0.001 to about 5 g/, an organic sulfide concentration in the range of about 0.0005 to about 1 g/,
and groups as mixtures of three or more.
It is contained in an amount such that the concentration of the brightener belonging to (c) is at least about 25 mg/ to about 0.5 g/or less.

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°F (16-38°C) and a cathodic current density of at least about 60 ASF.
(6.4 A/Dm ² ) and less than or greater than about 300 ASF (32 A/Dm ² ) and at least about 0.001 inch (0.025 cm) thick. A matched anode or multiple anodes are used to avoid regions of low current density below about 60 ASF (6.4 A/Dm ² ), thereby further depositing a substantially uniform thickness of copper on the substrate. Do it like this.

[Description of preferred embodiments]

To carry out the method of the invention, typically about
180 to about 250 g/copper sulfate, and about 30 to about 80 g/
Prepare a sulfate type acid plating aqueous bath containing sulfuric acid. A typical example of a modified version is about 200 to about 600 g/
A fluoroborate type bath may be provided containing copper fluoroborate and up to about 60 g/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.

This aqueous plating bath also contains approximately 0.2 g/h of halogen ions such as chlorine and/or bromide ions.
It can also be included in the following amounts: A halogen ion concentration of 0.2 g/ 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 are bath-soluble, compatible polyethers with at least four ethereal oxygens and an average molecular weight of about 180 to 1,000,000. Polypropylene glycol and polyethylene glycol and mixtures thereof with an average molecular weight of about 600 to about 6,000, aromatic alcohol alkoxylates with an average molecular weight of about 300 to 2,500 and average molecular weights of about 1,000 to about
Particularly satisfactory results are obtained using alkoxylates of 50,000 amines. Examples of satisfactory polyether gloss compounds include average molecular weights of approximately 400 to
about 1,000,000 polyethylene glycols; naphthol ethoxylates containing 5 to 45 moles of ethylene oxide groups; naphthol propoxylates containing 5 to 15 moles of propylene oxide groups; nonylphenol ethoxylates containing 5 to 30 moles of ethylene oxide groups; average molecular weight about 350 ~1000 propylene glycol; polyoxyethylene/polyoxypropylene glycol block polymer with an average molecular weight of about 350 to 250,000: 5 to 100 ethylene oxide groups
phenol propoxylates containing from 5 to 15 moles of propylene oxide groups and ethylenediamine block polymers having an average molecular weight of about 1,600 to about 30,000.
Other polyether compounds such as those disclosed in US Pat. No. 4,272,335 are also useful.

The usage amount of this polyether brightener is approximately 0.001 ~
It is generally in the range of about 5 g/, and the higher the molecular weight, the lower the concentration used.

Organic sulfide brightener (a) 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;
Included are organic sulfur compounds as listed in Table 1 of U.S. Pat. No. 4,181,582; and organic polysulfides listed in Table 1 of U.S. Pat. No. 3,328,273.

Organic sulfides having sulfonic or phosphonic groups also contain methyl,
Various substituents such as chloro, bromo, methoxy, ethoxy, carboxy or hydroxy may be included. 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 ₃ -P
Included are -( _CH2 ) ₃ -S-S-( _CH2 ) _{3 -} PO3H, as well as mercaptans, thiocarbamates, thiol carbamates, thiozensates and thiocarbonates having at least one sulfone or phosphonic group.

It is described in U.S. Patent No. 3328273,
A particularly preferable organic divalent sulfur compound group has the general formula
XR ₁ -(S) _o R ₂ SO ₃ H or XR ₁ -(S) _o R ₂ PO ₃ H [Here, R ₁ and R ₂ are the same or different alkylene groups having 1 to 6 carbon atoms, and X is hydrogen , SO ₃ H or PO ₃ H, and n is a number from about 2 to 5]. These organic divalent sulfur compounds are aliphatic polysulfides having at least two adjacent divalent 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 brightener or mixture thereof is present in the bath at a concentration ranging from about 0.0005 to about 1 g/g.

In addition to the brighteners consisting of polyether compounds (A) and sulfides (B), this plating bath also contains at least three brighteners consisting of compounds (A), (B), and (C) as essential brighteners. Contains agent compound (c). general formula
Brightener compounds corresponding to (A) are typically those described in US Pat. No. 2,882,209, particularly in the table therein. Representative examples of such brighteners include diethylsafranine azodimethylaniline (Janus Green
B), diethyl safranin azophenol (Janus Black), safranin azonaphthol (Janus Blue, Janus Gray) [Color Index 137,
Society of Dyers & Colourists, by FM
Rowe, (1924)], dimethylsafranine, azodimethylaniline, phenosafranine, “Fuchsia,
Amethyst Violet” and others.

The brightener compounds corresponding to general formula (B) consist of phthalocyanine derivatives which may be metal-free or which are divalent or trivalent linked by the coordination of the isoindole nitrogen atoms in the molecule. It may contain a value-stable metal selected from cobalt, nickel, chromium, iron or copper, and mixtures thereof, with copper being a typically preferred metal. .

Such phthalocyanine derivatives suitable for use in the practice of this invention are at least about 0.1 mg/
with a bath solubility of about 0.5 g/or less,
Preferably, about 25 to about 50 g/g is used. Suitable phthalocyanine derivatives are outlined in the following structural formula: [wherein, Substituted phthalocyanine derivatives suitable for use in the practice of the present invention further include U.S. Pat.
Includes what is disclosed in No. 4272335. A particularly preferred phthalocyanine derivative is Alcian Blue.

The organic brightener compound (C) 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 organic compounds containing active halogens such as aralkyl halides, alkyl halides, alkenyl and alkynyl halides, 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 secondary 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 that. 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 halogen.

When an alkylating agent reacts with a primary or secondary amine, it changes into a secondary amine and a tertiary amine, respectively. When alkylation occurs on general and/or secondary nitrogens, elimination of alkylated groups on organic compounds, ie halogens, sulfates, etc., occurs. However, in the case of tertiary nitrogens, quaternization occurs to form quaternary salts.

Good results are still obtained even if only about 5% of the nitrogen atoms are quaternized, 10% is even better, and 20% is even better.
% yields better results, but it is preferred that as many nitrogen atoms in the polyethyleneimine brightener be quaternized as possible.

The polyethyleneimine used to form the gloss additive can have a wide range of molecular weights. Typically, the molecular weight ranges from about 300 to several million. However, in many cases, the molecular weight is around 300~
Preferably, it is within the range of 1,000,000. The organic brightener compound (C) is preferably used in an amount of about 0.5 g/or less, preferably about 35 to about 100 mg/.

Organic brightener compounds (A), (B) and (C) in combination of at least three, at least about 25 mg/
, preferably in an amount of about 30-90 mg/.

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 controlled within about 60 DEG to about 100 DEG F. (16 DEG to 38 DEG C.), preferably about 70 DEG to about 90 DEG F. (21 DEG to 32 DEG C.).
If the temperature exceeds 100°C (38°C), a copper film with low ductility tends to form in many cases, which is undesirable. This copper electrodeposition is at least about 60 ASF
(6.4A/Dm ² ) and approximately 300ASF (32
A/Dm ² ), in special cases up to 300ASF (32A/D
^m2 ) or higher current density. The preferred cathode current density is about 100 to about 200 ASF (11 to 22 A/D
^m2 ). In order to deposit a substantially uniform thickness of copper on the substrate, the anode arrangement 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 conventional in rotogravure cylinder plating.

This unique copper plating deposited by the practice of the present invention is bright, smooth, ductile, and consists of substantially pure copper for use in electroforming, audio and video disc manufacturing, rotogravure cylinders, etc. It is eminently suitable for various engineering applications. Another characteristic of this copper plating is that it has a relatively uniform hardness, typically 100
Diamond pyramid hardness number with gram load
200 or more, has an extremely homogeneous and coaxial crystal structure, and has a particle size of about 1 micron or less. Engineering copper coatings made in accordance with the present invention have a thickness of at least about 0.001 inch (0.0025 cm) to about 0.050 inch (0.127 cm).
It is significantly different from ordinary decorative copper plating in that it has the unique property of not having self-annealing properties.

The method of the present invention is not suitable for the purpose of producing so-called decorative copper plating, since dark color stains occur in all low current density regions, such as average cathode current densities below 60 ASF (6.4 A/Dm ² ). Not applicable.

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

Example 1 Copper sulfate pentahydrate approximately 195g/, sulfuric acid 75g/,
A brightening agent (A) consisting of polypropylene oxide (molecular weight 750) containing about 20 to about 100 mg of chlorine ions and about 120 mg/; a brightening agent (I) consisting of about 21 mg/bis(3-sulfopropyl disulfate/2Na salt); ), about 15mg/
A brightener (c) corresponding to the general formula (A) consisting of Janus Green B of about 15 mg/cm, a brightener (c) corresponding to the general formula (B) consisting of about 15 mg/ml of Methic Turquoise, and quaternized with benzyl chloride. An acidic copper plating aqueous bath was prepared containing an organic brightener combination consisting of a brightener (c) corresponding to general formula (C) consisting of about 12 mg/ml of polyethyleneimine.

The bath temperature was controlled at approximately 80°C (27°C), and the rotogravure cylinder was immersed in the bath, surrounded by a matching copper anode, and rotated at 100 rpm while passing current between the working parts as the anode and cathode to generate approximately 150 ASF. (16A/
Dm ² ).

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

Example 2 About 195g/copper sulfate pentahydrate, 75g/sulfuric acid, about 20 to about 100mg/chloride ion, and about 60mg/
brightener (a) consisting of polyethylene oxide (molecular weight 3350), brightener (b) consisting of about 30 mg/bis(3-sulfopropyl disulfide, 2Na salt), about 10
A brightener (c) corresponding to the general formula (A) consisting of Janus Green B of mg/, corresponding to the general formula (B) of 10 mg/
An aqueous acidic copper plating bath was prepared containing a combination of organic brighteners consisting of Methic Turquoise and a brightener (C) corresponding to general formula (C) consisting of polyethyleneimine quaternized with benzyl chloride.

The bath temperature was controlled at approximately 75°C (24°C), and the rotogravure cylinder was immersed in the bath and surrounded by a matched copper anode.
While rotating the cylinder at 300 rpm, current was applied using the work piece as a cathode to obtain a current density of approximately 100 AST (10 A/Dm ² ).

The produced copper-plated film is completely bright, has good smoothness and ductility, and has a resistance of approx.
It had a hardness of over 200DPH. This copper-plated film had substantially no self-annealing property.

Example 3 About 195g/copper sulfate pentahydrate, 75g/sulfuric acid, about 20 to about 100mg/chloride ion, and about 120g/
A brightening agent (A) consisting of polypropylene oxide (molecular weight 750), a brightening agent (B) consisting of about 30 mg/bis(3-sulfopropyl disulfide, 2Na salt), and about 8 mg/Janus Green B. general formula
Brightener (C) equivalent to (A), approximately 22 mg/Methic
Brightener (C) corresponding to general formula (B) consisting of Turquoise
An acidic plating aqueous bath was prepared containing an organic brightener combination consisting of a brightener (c) corresponding to general formula (C) and a brightener (c) consisting of polyethyleneimine quaternized with benzyl chloride.

The bath temperature was controlled at approximately 70°C (21°C), and the rotogravure cylinder was immersed in the bath and surrounded by a matched copper anode.
While rotating the cylinder at 150 rpm, current was applied to the work piece as a cathode to achieve a current density of approximately 150 ASF (16 A/Dm ² ).

The produced copper-plated film has perfect brightness, good smoothness and ductility, and has a resistance of about 200% under a load of 100 grams.
(DPH) or higher. This copper-plated film had virtually no self-annealing properties.

Since it is evident 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 by the claims below. It is not something that will be done.

Claims (1)

[Claims] 1. A method for electrodepositing an engineering copper plating film on a conductive substrate that is extremely smooth, ductile, shiny, has substantially uniform hardness, and has no self-annealing properties. a copper component in an amount sufficient to deposit copper on the substrate; (a) at least one organic polyether compound; (b) at least one organic sulfide; and (c) a general formula [wherein R ₁ and R ₂ are groups selected from the group consisting of hydrogen, methyl and ethyl groups, and X is selected from the group consisting of chlorine, bromine, iodine, fluorine, sulfuric acid, bisulfuric acid and nitrate ions Anion, Y is H, _-NH2 , -N( _CH3 ) ₂ and -N=N-Z, Z
is an aromatic group selected from the group consisting of phenyl, naphthyl, and phenyl and naphthyl groups substituted with amino groups, alkyl-substituted amino groups, hydroxy and alkoxy substituents] Compound; General formula Pc-(X) _o (B) [In the formula, _Pc is phthalocyanine; X is _-SO2NR2 , _-SO3M , _-CH2SC ( _NR2 ) ₂
+Y-; R is H, alkyl having 1 to 6 carbon atoms, 6 carbon atoms
Aryl, aralkyl having 6 carbon atoms in the aryl position and 1 to 6 carbon atoms in the alkyl position, heteroartic rings having 2 to 5 carbon atoms and containing at least one nitrogen, oxygen, sulfur or phosphorus atom, and 1 to 5 carbon atoms are the above alkyl, aryl, aralkyl and heterocyclic rings containing an amino group, hydroxyl group, sulfone group or phosphonic group; n is 1 to 6; Y is hydrogen or an alkyl sulfate containing 1 to 4 carbon atoms in the alkyl position; M is H, Li, Na, K or Mg]; and at least one alkylated polyethyleneimine reaction product (C) having a quaternary nitrogen atom. preparing an acidic aqueous solution containing a controlled amount of a combination of bath-soluble and compatible organic brighteners; immersing a conductive substrate as a cathode in ^the solution; passing an electric current through the solution at a current density to electrodeposit an engineering copper plating onto the substrate to a thickness of at least 0.001 inch (0.0025 cm). 2. The method according to claim 1, characterized in that the brightener (a) is present in an amount of 0.001 to 5 g/. 3. A method according to claim 1, characterized in that the brightener (a) is present in an amount of 0.0005 to 1 g/g. 4 At least 25mg/~0.5g/ of the brightener (c)
2. A method as claimed in claim 1, characterized in that the method is present in an amount of . 5. The method according to claim 1, characterized in that the brightener (c) is present in an amount of 30 to 90 mg/. 6. During the electrodeposition of copper plating, the temperature of the acidic aqueous solution is
The method according to claim 1, further comprising the step of controlling the temperature within the range of 60° to 100° (16 to 38°C). 7. During the electrodeposition of copper plating, the temperature of the acidic aqueous solution is
The method of claim 1 further comprising the step of controlling within the range of 70 DEG to 90 DEG F. (21 DEG to 32 DEG C.). 8 The copper plating electrodeposition process on the substrate has an average current density
The method according to claim 1, characterized in that it is carried out at 300 ASF (32 A/Dm ² ) or less. 9 The copper plating electrodeposition process on the substrate has an average current density
A method according to claim 1, characterized in that it is carried out at 100-200 ASF (11-22 A/ ^Dm2 ). 10. The method according to claim 1, characterized in that the acidic aqueous solution further contains 0.2 g/or less of halogen ions. 11 Adjust the relative position of the anode immersed in the solution to the substrate to 60 to 300 ASF (6.4
32 A/Dm ² ).
The method described in section. 12 comprising a rotogravure cylinder in which the conductive substrate is immersed in the solution, and during the electrodeposition step of the copper plating, the cylinder is used to produce a copper plating of substantially uniform thickness; 2. The method of claim 1, further comprising the step of rotating.