KR101807696B1 - Aqueous copper colloid catalyst solution and electroless copper plating method for the electroless copper plating - Google Patents

Abstract

(A), (B), (C), and (C) a colloidal stabilizer, wherein the components (A) and (C) are mixed with a surfactant, By adding a catalyst to a non-conductive substrate using an aqueous copper colloid catalyst solution for electroless copper plating containing no surfactant or a small amount of surfactant and performing electroless copper plating, The stability with time is good. Further, since the catalytic activity is enhanced by the adsorption promoting preliminary treatment, the catalyst is provided and the electroless plating is performed, which is excellent in the uniformity of the deposited copper film and prevention of occurrence of uneven deposition.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a copper-colloidal catalyst solution and an electroless copper plating method for an electroless copper plating,

The present invention relates to an aqueous copper colloid catalyst solution for imparting a catalyst as a pretreatment when electroless copper plating is performed on a non-conductive substrate and the electroless copper plating method, and furthermore, the stability of the copper catalyst solution with respect to time is excellent, , A method of forming a copper film having an outer appearance with good uniformity and unevenness (unevenness).

A resin substrate such as a glass epoxy resin, a glass polyimide resin, an epoxy resin, a polyimide resin, a polycarbonate resin, an ABS resin, and a PET resin, a non-conductive substrate such as a glass substrate and a ceramic substrate In order to perform electroless copper plating, a noble metal such as palladium, silver, or platinum is first adsorbed on a substrate, which is used as a catalyst nucleus, and a copper film is deposited on the substrate with the electroless copper plating solution through the catalyst nucleus .

On the other hand, there is a catalyst addition method using a specific metal such as copper, nickel, cobalt or the like, which is inexpensive and does not use a noble metal catalyst. In the catalyst solution of the specific metal, the soluble metal salt is treated with a reducing agent to produce metal colloid particles, The basic principle is to use this as a catalyst nucleus.

Among them, the conventional aqueous copper colloid catalyst solution is as follows.

(1) Patent Document 1 (Japanese Patent Application Laid-Open No. 1990-093076, SANKO Special Metals)

A soluble copper salt, a dispersant, and a complexing agent are added, a reduction treatment is performed with a reducing agent, and a stabilizer is added to prepare a fine copper catalyst solution for electroless copper plating.

The dispersant is gelatin or a nonionic surfactant. The complexing agent is a dicarboxylic acid, an oxycarboxylic acid or the like. The reducing agent is sodium borohydride, dimethylamine borane or the like. The stabilizer is sodium hypophosphite and dimethylamine borane.

Further, in Example 4 (upper left column on page 4), electroless copper plating was carried out after dipping the substrate in a catalyst solution containing copper sulfate, gelatin, sodium borohydride and hypophosphite.

(2) Patent Document 2 (Japanese Patent Application Laid-Open No. 1998-229280, Okuno Pharmaceutical)

An electroless plating catalyst composed of a copper salt, an anionic surfactant and a reducing agent is applied to the object to be plated, electroless copper plating is performed, and then electroplating is performed (Claims 1 and 2).

In Production Example 2 (paragraph 52), which is a specific example of the copper catalyst solution, the catalyst solution contains a copper complex with copper sulfate and ammonia, an anionic surfactant and sodium borohydride (reducing agent).

(3) Patent Document 3 (Japanese Patent Application Laid-Open No. 1995-197266, LeaRonal, Japan)

(I) colloid catalyst solution on the substrate, the copper is immersed in a solution containing a copper salt, a reducing agent and a complexing agent to directly coat copper on the substrate, A complexing agent and a reducing agent, but the composition of the catalyst solution is unclear.

(4) Patent Document 4 (Japanese Patent Application Laid-Open No. 2011-225929, Kanto Gakuin University)

A method for producing a catalyst solution comprising a cuprous salt, a hypophosphite and a chlorine ion (Claim 1) or further comprising an organic or inorganic reducing agent (amine borane, boron hydride compound, formic acid, etc.) (Claims 1 to 3) , And a method of pretreating the material to be plated with a conditioning agent including a surfactant (cationic, anionic, cationic, nonionic, paragraph 56), carrying out a catalytic treatment in the catalyst solution, 9).

The type of electroless plating is copper, nickel, gold, etc., and electroless copper plating is preferable (paragraph 70).

In addition, in the above-mentioned conditioning agent, in particular, when a cationic surfactant is used, the hydrophilic group of the surfactant adsorbed on the object to be plated is negatively charged, the copper ion is easily adsorbed, It has been described that it is possible to obtain fugitive material (paragraph 58).

(5) Patent Document 5 (Japanese Published Patent Application No. 2013-522476; Enthone Inc.)

A non-conductive substrate is treated with an activator solution comprising a noble metal / metal-colloid (e.g., palladium / tin colloid solution) and then a solution containing a metal salt solution such as a copper salt and a complexing agent of the metal ion with a reducing agent A direct metallization of a non-conductive substrate is carried out in which electroless plating and electroplating are performed after contact with a sieving solution (paragraphs 1 and 13).

The metal salt of the conductor solution is reduced to the metal of the activator solution, for example, the divalent tin (oxidizing cation) of the activator solution acts on the divalent copper ion (reducing cation) of the conductor solution, As tin is oxidized 4 times, divalent copper ions are reduced to metal copper (paragraphs 24 and 29).

In Example 1, the ABS plastic substrate was activated in a dispersion of an activator containing a palladium-tin colloid, and then treated with a mixture of tartaric acid (complexing agent), hypophosphite (or hypophosphite and hydroxymethylsulfonate; reducing agent) And a lithium salt or the like (paragraph 65, Table 1 in paragraph 66).

Japanese Patent Laid-Open No. 2-093076 Japanese Patent Application Laid-Open No. 10-229280 Japanese Patent Application Laid-Open No. 7-197266 Japanese Patent Application Laid-Open No. 2011-225929 Japan Specification Sheet 2013-522476

However, in the above-mentioned aqueous catalyst solution, the basic principle is that the soluble metal salt is treated with a reducing agent to produce fine particles of metal. However, since there are many problems with respect to stability over time including the catalyst solution of the patent documents, It is a reality that it is not easy to secure continuity of the electroless plating work for a long time smoothly.

Further, even when the electroless plating is performed after the non-conductive substrate is subjected to catalytic treatment with the copper catalyst liquid, it is difficult to precipitate or undergo partial plating precipitation, to cause plating defects, to cause unevenness in the plating film, There is a problem of.

SUMMARY OF THE INVENTION It is a technical object of the present invention to improve the stability of the aqueous copper catalyst solution with the elapse of time and to conduct electroless copper plating on the catalyst-imparted non-conductive substrate to obtain a uniform and uneven copper film.

The inventors of the present invention have found that, for example, in Patent Document 1, stabilizers are used in order to maintain a reduced state of copper. In order to stabilize the colloid particles by first adding a component having a complexing function to the copper salt in the catalyst liquid, .

It is also possible to add a colloidal stabilizer such as an oxycarboxylic acid or an aminocarboxylic acid to stabilize the copper salt in the copper catalyst liquid and to improve the stability with the elapse of time by adjusting the mixing ratio of the copper salt and the stabilizer, The presence of the water-soluble polymer adversely affects the stability over time, so that even when added, the content thereof should be kept to a very small amount, and the presence of the predetermined water-soluble polymer contributes greatly to the stability over time.

According to this finding, if the preliminary treatment of immersing the substrate in a solution containing an adsorption promoter made of a surfactant is carried out before the catalyst is added with the copper catalyst liquid, the catalytic activity at the time of catalyst application becomes high, The present invention has been completed on the basis that it is excellent in the uniformity of the obtained precipitation film and in preventing appearance stain of the film.

That is, the present invention 1 is an aqueous copper colloid catalyst solution for bringing a catalyst into contact with a non-conductive substrate to be subjected to electroless copper plating,

(A) a soluble copper salt,

(B) a reducing agent,

(C) at least one kind of colloidal stabilizer selected from the group consisting of monocarboxylic acids, oxycarboxylic acids, aminocarboxylic acids and polycarboxylic acids, wherein the molar ratio of the components (A) and (C) = 1: 0.03 to 1:35,

Wherein the surfactant-free water-based copper-colloidal catalyst solution contains no surfactant or the content of the surfactant is 950 mg / L or less.

The present invention 2 is an aqueous copper colloid catalyst solution for bringing a catalyst into contact with a non-conductive substrate to be subjected to electroless copper plating,

(A) a soluble copper salt,

(B) a reducing agent,

(C) a colloidal stabilizer selected from the group consisting of monocarboxylic acids, oxycarboxylic acids, aminocarboxylic acids and polycarboxylic acids, wherein the molar ratio of the components (A) and (C) is A: C = 1: 0.03 to 1:35,

Soluble copper-colloidal catalyst solution for electroless copper plating.

The present invention 3 is an electroluminescent material characterized in that the synthetic water-soluble polymer is at least one selected from the group consisting of polyethylene glycol, polypropylene glycol, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylamide and polyethyleneimine, It is a water-based copper colloid catalyst liquid for plating.

A fourth aspect of the present invention is the fourth aspect of the present invention, wherein the reducing agent (B) is at least one selected from the group consisting of a borohydride compound, an amine borane, a hypophosphorous acid, an aldehyde, an ascorbic acid, a hydrazine, a polyhydric phenol, Is at least one member selected from the group consisting of sulfuric acid, sulfuric acid, sulfuric acid, sulfuric acid, sulfuric acid, sulfuric acid, sulfuric acid, phenolsulfonic acids, naphtholsulfonic acids and sulfinic acids.

A fifth aspect of the present invention is the fifth aspect of the present invention, wherein in the first to fourth inventions, the monocarboxylic acids (C) are at least one selected from the group consisting of formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, capric acid, , Myristic acid, palmitic acid, stearic acid, and salts thereof. The electrolytic copper-colloidal catalyst solution for electroless copper plating is an aqueous copper colloid catalyst solution.

A sixth aspect of the present invention relates to any one of the first to fifth aspects of the present invention, wherein the oxycarboxylic acid (C) is at least one selected from the group consisting of citric acid, tartaric acid, malic acid, gluconic acid, glucoheptonic acid, glycolic acid, lactic acid, trioxybutyric acid, Wherein the aqueous copper hydroxide for electroless copper plating is at least one selected from the group consisting of citric acid, cornic acid, iso citric acid, tartronic acid, glyceric acid, hydroxybutyric acid, leucine acid, citramalic acid, Colloidal catalyst solution.

In the present invention 7, the aminocarboxylic acids (C) are preferably selected from the group consisting of hydroxyethylethylenediamine triacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, ethylenediaminetetraacetic acid , Ethylenediaminetetrapropionic acid, nitrilotriacetic acid, iminodiacetic acid, hydroxyethyliminodiacetic acid, iminodipropionic acid, 1,3-propanediamine tetraacetic acid, 1,3-diamino-2-hydroxypropanetetraacetic acid, glycol N, N ', N'-tetraacetic acid, diaminopropionic acid, glutamic acid, dicarboxymethylglutamic acid, ornithine, cysteine, N, N-bis (2-hydroxyethyl) glycine, (S, S) -ethylenediamine succinic acid and salts thereof At least one kind of copper-colloidal catalyst solution for electroless copper plating.

In the present invention 8, in any one of the inventions 1 to 7, the polycarboxylic acids (C) are selected from the group consisting of succinic acid, glutaric acid, malonic acid, adipic acid, oxalic acid, maleic acid, citraconic acid, itaconic acid, mesa And at least one member selected from the group consisting of hydrofluoric acid, hydrofluoric acid, hydrofluoric acid, hydrofluoric acid, hydrofluoric acid, hydrofluoric acid, hydrofluoric acid, hydrofluoric acid, hydrofluoric acid, hydrofluoric acid, hydrofluoric acid,

(9) An adsorption promoting step ((a)) of immersing a non-conductive substrate in a liquid containing at least one adsorbent selected from the group consisting of a nonionic surfactant, a cationic surfactant, an anionic surfactant and an amphoteric surfactant Preprocessing step)

(b) a catalyst imparting step of immersing the non-conductive substrate in the aqueous copper colloid catalyst solution of any of the above inventions 1 to 8 to adsorb copper colloid particles on the surface of the substrate,

(c) an electroless copper plating process for forming a copper film on the substrate subjected to the adsorption treatment using an electroless copper plating solution.

The present invention 10 is an electroless copper plating method characterized in that the adsorption promoter of the step (a) is a cationic surfactant and / or an amphoteric surfactant.

In the copper-colloidal catalyst solution of the present invention, a colloidal stabilizer capable of acting as a complex in the copper salt is contained to specify the ratio of the stabilizer to the copper salt, and a predetermined amount of a stabilizer such as polyethylene glycol, polyvinyl pyrrolidone and polyvinyl alcohol It is possible to remarkably improve the stability with time of the liquid by containing the water-soluble polymer or, conversely, containing no surfactant or containing only a very small amount.

In addition, in the metal-containing liquid (i.e., the catalyst liquid) of Patent Document 1, there is no ingredient for complexing the copper salt. In the catalyst liquid of Example 4 of Patent Document 1 (upper left column to upper right column of page 4), 1000 mg / L of gelatin was dispersed as the dispersing agent or in the catalyst solution of Production Example 2 (paragraph 52) of Patent Document 2, And 1000 mg / L of the surfactant, all exceeding the upper limit of the specified amount of the surfactant in the catalyst solution of the present invention 1.

In the present invention, the copper-colloidal catalyst is applied to a non-conductive substrate and then electroless copper plating is performed. As a pretreatment or pretreatment of the catalyst application, the non-conductive substrate is immersed in a surfactant- By carrying out the adsorption promoting step, the catalyst imparting step and the electroless copper plating step in succession by adding the adsorption promoting treatment, the catalytic activity at the time of catalyst addition is enhanced to improve the uniformity of the copper film deposited by electroless plating , It is possible to satisfactorily prevent occurrence of unevenness of the coating film.

(A) a soluble copper salt, (B) a reducing agent, and (C) a colloidal stabilizer, wherein the component (A) is a copper colloid, ) And (C), and is a water-based copper colloid catalyst liquid for electroless copper plating which contains no surfactant or contains only a very small amount. Second, the content of the surfactant is excluded or a predetermined amount Aqueous copper-colloid catalyst solution containing a synthetic water-soluble polymer, and third, an electroless copper plating method using the first or second catalyst solution, wherein the non-conductive substrate is pre- Containing solution, followed by catalyst addition by the catalyst solution, and electroless copper plating is carried out.

The non-conductive substrate refers to a resin substrate such as a glass epoxy resin, a glass polyimide resin, an epoxy resin, a polyimide resin, a polycarbonate resin, an ABS resin or a PET resin, and also a glass substrate or a ceramic substrate.

The basic composition of the aqueous copper colloid catalyst solution of the present invention 1 is (A) a soluble copper salt, (B) a reducing agent, and (C) a colloidal stabilizer.

The soluble copper salt (A) can be any salt as long as it is a soluble salt for generating the first or second copper ion in an aqueous solution. There is no particular limitation, and the poorly soluble salt is not excluded. Specifically, there may be mentioned copper sulfate salts such as copper sulfate, copper oxide, copper chloride, copper pyrophosphate, copper carbonate, copper carboxylate such as copper acetate, copper oxalate and copper citrate, or organic sulfonate copper salts such as copper methanesulfonate and copper hydroxyethanesulfonate And copper sulfate, copper citrate, and copper methanesulfonate are preferable.

Examples of the reducing agent (B) include a borohydride compound, an amine borane, a hypophosphorous acid, an aldehyde, an ascorbic acid, a hydrazine, a polyhydric phenol, a divalent phenol, a phenol sulfonic acid, a naphthosulfonic acid, a sulfinic acid ), And the like. The aldehydes include formaldehyde, glyoxylic acid and salts thereof, and the polyhydric phenols include catechol, hydroquinone, resorcine, pyrogallol, fluoroglucine and gallic acid. The phenolsulfonic acids include phenolsulfonic acid, Sulfonic acid or a salt thereof.

The colloidal stabilizer (C) is a compound which forms a copper complex in a plating bath, and performs the function of securing the stability of the catalyst solution with respect to time.

The colloidal stabilizer (C) is selected from the group consisting of monocarboxylic acids, oxycarboxylic acids, aminocarboxylic acids and polycarboxylic acids.

Examples of the monocarboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, have.
The oxycarboxylic acids include citric acid, tartaric acid, malic acid, gluconic acid, glucoheptane, glycolic acid, lactic acid, trioxybutyric acid, ascorbic acid, isocitric acid, tartronic acid, glyceric acid, hydroxybutyric acid, Malic acid and salts thereof.

Examples of the aminocarboxylic acids include ethylenediaminetetraacetic acid (EDTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA), triethylenetetraminehexaacetic acid (TTHA), ethylenediaminetetrapropionic acid , Nitrilotriacetic acid (NTA), iminodiacetic acid (IDA), iminodipropionic acid (IDP), hydroxyethyliminodiacetic acid, 1,3-propanediamine tetraacetic acid, 1,3-diamino- N, N ', N'-tetraacetic acid, diaminopropionic acid, glutamic acid, dicarboxymethylglutamic acid, dicarboxylic acid, acetic acid, Tin, cysteine, N, N-bis (2-hydroxyethyl) glycine, (S, S) -ethylenediamine succinic acid and salts thereof.

Examples of the polycarboxylic acids include succinic acid, glutaric acid, malonic acid, adipic acid, oxalic acid, maleic acid, citraconic acid, itaconic acid, mesaconic acid and salts thereof.

Since the copper colloid catalyst solution of the present invention is aqueous, the solvent of the solution is limited to water and / or hydrophilic alcohol, and the use of an organic solvent (including oleophilic alcohol) alone is excluded.

The pH of the solution is preferably acidic or alkaline, except for the neutral region. Specifically, the pH of the solution is preferably from pH 1 to 6 and pH 8 to 12, Preferably pH 2-5 and pH 8-11.

The content of the soluble copper salt (A) in the aqueous copper colloid catalyst solution can be used alone or in combination, and the content thereof is 0.005 to 1 mol / L, preferably 0.05 to 0.5 mol / L, more preferably 0.04 to 0.5 mol / 0.2 mol / L.

The reducing agent (B) can be used alone or in combination, and its content is 0.005 to 1 mol / L, preferably 0.05 to 0.5 mol / L. If the content of the reducing agent is less than the proper amount, the reducing action of the copper salt is lowered, and if it is excessively large, the homogeneity of the copper film deposited by electroless plating may be deteriorated.

The colloidal stabilizer (C) can be used alone or in combination, and its content is 0.005 to 2 mol / L, preferably 0.05 to 1.5 mol / L.

In the aqueous colloidal catalyst solution, the molar ratio of A to C is 1: 0.03 to 1:35, and A: C is 1: 0.5 to 1: 24. If the relative content of the colloidal stabilizer (C) is too low, the stability of the catalyst solution with the elapse of time tends to deteriorate, and furthermore, the precipitation failure occurs in the copper film obtained by electroless plating. Conversely, if the content of the colloidal stabilizer (C) is too high, the stability of the catalyst solution with time is deteriorated, and the quality of the obtained copper coating film is lowered (see test examples described later).

In the aqueous colloidal catalyst solution, the molar ratio of the components (A) and (B) is 1: 0.05 to 1: 6, preferably 1: 0.1 to 1: 5.

In the preparation of the catalyst liquid, electrons are smoothly supplied from the reducing agent to the copper ion, so that the reducing agent solution is slowly added dropwise to the soluble copper salt (and colloid stabilizer) -containing solution over a period of time. For example, a reducing agent solution of 5 to 50 캜 (preferably 10 to 40 캜) is dropped into a copper salt solution and stirred for 20 to 1,200 minutes (preferably 30 to 300 minutes) to prepare a catalyst solution. In the preparation of the catalyst liquid, it is not excluded to drop the soluble copper salt solution into the reducing agent solution.

In the catalyst solution of the present invention, the copper colloid particles produced in the soluble copper salt by the action of the reducing agent are fine particles having an appropriate average particle diameter of 1 to 250 nm, preferably 1 to 120 nm, more preferably 1 to 100 nm.

When the average particle size of the copper colloidal particles is 250 nm or less, when the non-conductive substrate is immersed in the catalyst liquid, the colloidal particles enter the grooves of the fine uneven surface of the substrate and are densely adsorbed or held in the grooves. It is presumed that the application of copper colloid nuclei to the substrate surface is promoted. Conversely, if the average particle diameter is larger than 250 nm, it is difficult to obtain stable copper colloid due to coagulation, sedimentation or separation, and an anchor effect can not be expected. Therefore, copper colloid particles can only partially be imparted to the substrate surface There is a risk of failure.

In the aqueous copper colloid catalyst solution of the present invention 1, it is necessary to contain no surfactant or to suppress the content of the surfactant to 950 mg / L or less.

When the surfactant is contained in the catalyst liquid, there is a possibility that the catalytic activity is lowered, and it is preferable that no surfactant is added. However, when the content is an extremely small amount of 950 mg / L or less, there is no adverse effect on catalyst activity lowering, and it is preferably 700 mg / L or less.

The surfactant refers to various nonionic, amphoteric, cationic or anionic surfactants. In particular, positive, cationic, anionic or low molecular weight nonionic surfactants are not preferred.

Examples of the nonionic surfactant include C ₁ -C ₂₀ alkanol, phenol, naphthol, bisphenols, (poly) C ₁ -C ₂₅ alkylphenol, (poly) arylalkylphenol, C ₁ -C ₂₅ alkylnaphthol, C (EO) and / or propylene oxide (PO) to ₁ to C ₂₅ alkoxylated phosphates (salts), sorbitan esters, polyalkylene glycols, C ₁ to C ₂₂ aliphatic amines, C ₁ to C ₂₂ aliphatic amides, 2 to 300 mols of the condensation product.

Examples of the cationic surfactant include quaternary ammonium salts and pyridinium salts. Specific examples thereof include lauryltrimethylammonium salt, stearyltrimethylammonium salt, lauryldimethylethylammonium salt, octadecyldimethylethylammonium salt, dimethyl There may be mentioned, for example, benzylamine, benzylamine, benzylamine, benzylamine, benzylamine, ethylbenzylamine, benzylamine, benzylamine, Stearylamine acetate, laurylamine acetate, octadecylamine acetate, and the like.

Examples of the anionic surfactant include alkyl sulfates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkyl phenyl ether sulfates, alkyl benzyl sulfonates, and {(mono, di (tri) alkyl} naphthalenesulfonates. Also, sulfated or sulfonated adducts of condensation products of ethylene oxide and / or propylene oxide with alkyl amines or diamines can be used.

The aqueous copper colloid catalyst liquid of the present invention 2 is the same as the basic composition of the same catalyst liquid of the present invention 1 and contains (A) a soluble copper salt, (B) a reducing agent and (C) a colloid stabilizer as essential components, The mixing ratio requirements of the components (A) and (C) are also the same as those of the first invention.

The catalyst liquid of the present invention 2 is characterized by containing a synthetic water-soluble polymer in lieu of the requirements of the present invention 1 in which the content of the surfactant is suppressed to 0 but is suppressed to an extremely small amount or less.

When the synthetic water-soluble polymer is contained in the catalyst liquid, the dispersibility of the colloidal particles is improved, thereby contributing to excellent uniformity and precipitation of uneven copper film upon electroless copper plating.

The synthetic water-soluble polymer is meant to exclude a naturally occurring water-soluble polymer such as gelatin and starch.

The synthetic water-soluble polymer as the object of the present invention 2 containing the catalyst liquid may partially overlap the components thereof due to the presence or absence of the catalyst liquid of the present invention 1 or the surfactant to be inhibited. However, It is a separate concept.

In the catalyst liquid of the present invention 2, it is not necessary to contain components other than the water-soluble polymer, and therefore it may or may not be contained in the catalyst liquid regardless of the presence or absence of the surfactant. , And it is preferable that it does not contain a surfactant.

(PEG), polypropylene glycol (PPG), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), polyacrylamide (PAM), and the like are used as the synthetic water- , Polyethyleneimine (PEI), and polyacrylic acid salt. Particularly, PEG, PVP and PVA having high molecular weight are preferable.

The synthetic water-soluble polymer may be used singly or in combination, and the content thereof in the catalyst liquid is 0.05 to 100 g / L, preferably 0.5 to 50 g / L, more preferably 1.0 to 30 g / L.

The present invention 9 is an electroless plating method using the aqueous copper colloid catalyst solution, and the following three steps are sequentially combined.

(a) Adsorption promotion process

(b) Catalyst application step

(c) Electroless copper plating process

The adsorption promoting step (a) is a pretreatment (pretreatment) step of so-called catalyst addition (b) and is an adsorption promoter selected from the group consisting of nonionic surfactants, cationic surfactants, anionic surfactants and amphoteric surfactants A step of immersing a non-conductive substrate in a liquid containing at least one kind of a surfactant, wherein the substrate is brought into contact with a surfactant-containing liquid to increase the wettability of the substrate surface and to enhance the catalytic activity and promote the adsorption of the copper- will be.

In the adsorption promoting step, it is necessary to bring the non-conductive substrate into contact with the surfactant-containing liquid, so it is essential to immerse the substrate in the liquid, but there is no problem even if the liquid is sprayed onto the substrate or applied with a brush.

As shown in the present invention 10, from the viewpoint of promoting adsorption, a cationic surfactant with a positive charge and a positive surfactant are suitable, and a cationic surfactant is particularly preferable. When a cationic surfactant is used in combination with a small amount of a nonionic surfactant, the adsorption promoting effect is further increased.

In the catalyst solution of the present invention 1 or 2, since the zeta potential of the copper colloid particles produced by reacting the soluble copper salt with the reducing agent is negative, for example, when the non-conductive substrate is treated with the cationic surfactant , The substrate tends to have a positive charge, and the substrate adsorption efficiency of the copper colloid particles in the next step increases.

The specific examples of the surfactant are the same as the description of the surfactant described as an object to be excluded or inhibited in the catalyst solution of the first invention.

The content of the surfactant is 0.05 to 100 g / L, preferably 0.5 to 50 g / L. The temperature of the surfactant-containing liquid is preferably about 15 to 70 DEG C, and the immersion time is preferably about 0.5 to 20 minutes.

After the non-conductive substrate having undergone the adsorption promoting treatment is cleaned with the pure substance, the process proceeds to the next catalyst application step (b) without drying or drying treatment.

In the catalyst imparting step, the non-conductive substrate is immersed in the aqueous copper colloid catalyst solution, and the copper colloid particles are adsorbed on the surface of the substrate.

The temperature of the catalyst liquid is about 10 to 70 DEG C and the immersion time is about 0.1 to 20 minutes. In the immersion treatment, it is sufficient to immerse the substrate in the catalyst liquid in the stationary state, but stirring or rocking treatment may be performed.

The non-conductive substrate immersed in the catalyst liquid is cleaned with a pure substance, and then the process proceeds to the electroless copper plating process (c) without drying or drying process.

Electroless copper plating can be performed in the same manner as in the conventional method, and there is no particular limitation. The solution temperature of the electroless copper plating solution is generally from 15 to 70 캜, preferably from 20 to 60 캜.

For the stirring of the copper plating solution, air agitation, rapid liquid agitation, mechanical agitation by a stirring blade, and the like can be used.

The composition of the electroless copper plating solution is not particularly limited, and a known copper plating solution can be used.

The electroless copper plating solution may basically contain a soluble copper salt, a reducing agent and a complexing agent, or may further contain various additives such as a surfactant and a pH adjusting agent or an acid.

The soluble copper salt is as described above for the copper colloid catalyst solution.

As for the reducing agent contained in the electroless copper plating solution, as described in the copper colloid catalyst solution, it is possible to use formaldehyde (formalin water) as well as hypophosphoric acids, phosphorous acids, amine borane, hydrogenated boron, And the formalin number is preferable.

The complexing agent contained in the electroless copper plating solution has a portion which is common to the colloidal stabilizer described in the copper colloid catalyst solution. Specifically, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA ), Aminocarboxylic acids such as triethylenetetraminehexaacetic acid (TTHA), hydroxyethylethylenediamine triacetic acid (HEDTA), nitrilotriacetic acid (NTA) and iminodiacetic acid (IDA), ethylenediamine, tetramethylenediamine, Polyamines such as methylene diamine, diethylenetriamine, tetraethylenepentamine and pentaethylenehexamine, aminoalcohols such as monoethanolamine, diethanolamine and triethanolamine, oxycarboxylic acids such as citric acid, tartaric acid, lactic acid and malic acid , Thioglycolic acid, glycine, and the like.

The electroless copper plating solution may contain an organic acid, an inorganic acid, or a salt thereof as a liquid base component.

Examples of the inorganic acid include sulfuric acid, pyroluric acid, and borofluoric acid. Examples of the organic acid include oxycarboxylic acids such as glycolic acid and tartaric acid, and organic sulfonic acids such as methanesulfonic acid and 2-hydroxyethanesulfonic acid.

(Example)

Examples of the electroless copper plating method including the production of the adsorption promoting agent-containing liquid, the copper colloid catalyst solution, and the electroless copper plating solution of the present invention are described below. In addition, examples of the stability test of the copper colloid catalyst solution, The appearance evaluation test examples of the precipitated copper film obtained in the above examples will be described in turn.

Here, the present invention is not limited to the following examples and test examples, and it goes without saying that certain modifications can be made within the scope of the technical idea of the present invention.

≪ Embodiment of Electroless Copper Plating Method >

In Examples 1 to 18, Example 7 shows that the copper colloid catalyst solution contains a very small amount of surfactant, Examples 1 to 4, Examples 8 to 12, and Example 18 each contain a surfactant in the catalyst solution Examples 5 to 6, Example 9 and Examples 13 to 17 are examples in which a synthetic water-soluble polymer is contained in the catalyst liquid.

Example 1 is an example in which citric acid is used as a colloidal stabilizer in the catalyst solution and sodium borohydride is used as a reducing agent. In Example 2, the content of the colloidal stabilizer is reduced. In Example 3, the content of the colloidal stabilizer is increased. In Example 4, the content of the reducing agent is reduced. In Example 8, Examples in which the type and content of the stabilizer are changed, Example 9 is an example in which the kind of the reducing agent and the liquid temperature of the catalyst liquid are changed. On the basis of Example 9, Examples 10 to 11 and 15 are examples in which the soluble copper salt is changed, and Example 12 is an example in which the colloidal stabilizer is changed.

Example 7 is an example in which an extremely small amount of a nonionic surfactant is used and the kind of the colloidal stabilizer and the pH of the catalyst liquid are changed based on Example 1 as described above.

On the basis of Example 1, Example 5 is an example in which polyvinylpyrrolidone (PVP) is contained in the catalyst solution, Example 6 contains polyethylene glycol (PEG) in the same manner, Example 9 and Example 14 is an example containing PVP (changing the average molecular weight), Example 13 is an example containing polyethyleneimine (PEI), and Example 15 is an example containing polyacrylamide (PAM).

In Examples 1 to 15, the pH of the catalyst liquid is acidic, while in Examples 16 to 18, the pH of the catalyst liquid is alkaline. In addition, about 10 to 20% of sulfuric acid or sodium hydroxide was used for pH adjustment.

On the other hand, in Comparative Examples 1 to 6 of the following Comparative Examples 1 to 6, the relative content ratios of the colloidal stabilizer to the copper salt in the catalyst solution in the catalyst solution and the catalyst solution in Comparative Example 2, In Comparative Example 3, the content of copper exceeds the upper limit of the amount specified in the present invention 1 to 2. In Comparative Example 4, the amount of the surfactant in the catalyst solution exceeds the inhibiting amount specified in the present invention 1 And Comparative Example 5 is an example in which the catalyst solution contains more surfactant than Comparative Example 4, and Comparative Example 6 is a control example in which the electroless plating process is performed in the catalyst addition process immediately without the adsorption promoting process.

In Example 4 of Patent Document 1 described in the opening paragraph, gelatin was contained as a dispersant in the catalyst liquid, whereas Comparative Example 7 contained gelatin, which is a water-soluble polymer derived from a naturally occurring, , Which is a reference example of the so-called Patent Document 1.

(1) Example 1

(a) Preparation of adsorption accelerator-containing liquid

An adsorption accelerator-containing liquid was prepared with the following composition.

     [Adsorption accelerator-containing liquid]

  Quaternary ammonium salt of diarylamine polymer -------- 5 g / L

  Polyoxyalkylene branched decyl ether --------- 1 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

     [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------- 0.2 mol / L

  Citric acid ----------------------------- 0.6 mol / L

     [Reducing agent solution]

  Sodium borohydride - 0.2 mol / L

The reducing agent solution was added dropwise to the copper solution at 25 ° C adjusted to pH 4.0 and stirred for 45 minutes to prepare an aqueous copper colloid catalyst solution.

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: colloid stabilizer = 1: 3, copper salt: reducing agent = 1: 1

The average diameter of the copper colloidal particles produced was about 10 nm.

(c) Preparation of electroless copper plating solution

The electroless copper plating solution was humidified by the following composition. The pH of the plating solution was adjusted with sodium hydroxide shown below.

     [Electroless copper amount amount]

Copper sulfate pentahydrate (as Cu ^{2 +} ) ------------ 2.0 g / L

  Formaldehyde ------------------------ 5.0 g / L

  EDTA ---------------------------- 30.0 g / L

  Sodium hydroxide ------------------------ 9.6 g / L

  Residual -----------------------------

  pH (20 < 0 > C) - 12.8

(d) Treatment conditions of electroless copper plating

First, a glass-epoxy resin substrate (FR-4 manufactured by Panasonic Electric Works Co., Ltd., thickness: 1.0 mm) serving as a non-conductive substrate was used as a sample substrate.

After the adsorption promoting treatment is applied to the sample substrate using the adsorption promoter of (a), the substrate is immersed in the catalyst solution of (b) to perform a catalyst imparting treatment, and electroless copper plating is performed in the plating solution of (c) Respectively.

Specifically, the sample substrate was immersed in the adsorption-promoting agent-containing liquid at 50 DEG C for 2 minutes and washed with a pure substance. Subsequently, the sample substrate subjected to the adsorption promoting treatment (pretreatment) was immersed in the copper colloid catalyst solution at 25 DEG C for 10 minutes and washed with the pure substance. Thereafter, the sample substrate to which the catalyst was applied was immersed in the electroless copper plating solution and subjected to electroless plating at 50 DEG C for 10 minutes. A copper film was formed on the sample substrate, followed by washing with pure substance and drying .

(2) Example 2 (Example of reducing the colloidal stabilizer of Example 1)

Based on the above Example 1, except that the adsorption promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the production method of the copper colloid catalyst solution or the electroless copper plating solution and the treatment conditions of each step were the same as in Example 1 .

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: colloidal stabilizer = 1: 0.2, copper salt: reducing agent = 1: 1

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Lauryldimethylbenzylammonium chloride -------------- 5 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Citric acid ---------------------------------- 0.04 mol / L

      [Reducing agent solution]

  Sodium borohydride - 0.2 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 4.0 and stirred for 45 minutes.

The average diameter of the copper colloid particles produced was about 15 nm.

(3) Example 3 (Example in which the colloidal stabilizer of Example 1 is increased)

Based on the above Example 1, except that the adsorption promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the production method of the copper colloid catalyst solution or electroless copper plating solution and the treatment conditions of each step were the same as in Example 1 .

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: colloid stabilizer = 1: 15, copper salt: reducing agent = 1: 1

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Lauryldimethylaminoacetic acid betaine -------------- 5 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Citric acid ----------------------------------- 3.0 moles / L

      [Reducing agent solution]

  Sodium borohydride - 0.2 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 4.0 and stirred for 45 minutes.

The average diameter of the copper colloid particles produced was about 12 nm.

(4) Example 4 (Reduction of reducing agent of Example 1)

Based on the above Example 1, except that the adsorption promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the production method of the copper colloid catalyst solution or the electroless copper plating solution and the treatment conditions of each step were the same as in Example 1 .

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: colloidal stabilizer = 1: 4, copper salt: reducing agent = 1: 0.5

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Quaternary ammonium salt of diarylamine polymer --------------- 5 g / L

  Polyoxyalkylene branched decyl ether ----------------- 1 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Citric acid ---------------------------------- 0.8 mol / L

      [Reducing agent solution]

  Sodium borohydride -------------------------- 0.01 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 4.0 and stirred for 45 minutes.

The average diameter of the copper colloid particles produced was about 25 nm.

(5) Example 5 (Example in which the reducing agent of Example 1 is increased)

Based on the above Example 1, except that the adsorption promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the production method of the copper colloid catalyst solution or the electroless copper plating solution and the treatment conditions of each step were the same as in Example 1 .

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: colloidal stabilizer = 1: 4, copper salt: reducing agent = 1: 2.25

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Quaternary ammonium salt of diarylamine polymer --------------- 5 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Citric acid ---------------------------------- 0.8 mol / L

  Polyvinylpyrrolidone (average molecular weight: 40,000) - 2.0 g / L

      [Reducing agent solution]

  Sodium borohydride 0.45 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 4.0 and stirred for 45 minutes.

The average diameter of the copper colloidal particles produced was about 8 nm.

(6) Example 6 (colloidal stabilizer of Example 1, reduction example reduced, stirring time extended)

Based on the above Example 1, except that the adsorption-promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, a copper colloid catalyst solution (except for stirring time) or a method of producing electroless copper- The processing conditions of the process were the same as those in Example 1.

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: Colloidal stabilizer = 1: 3, Copper salt: Reducing agent = 1: 0.5

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Lauryldimethylbenzylammonium chloride --------------- 5 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Citric acid ----------------------------------- 0.6 mol / L

  Polyethylene glycol (average molecular weight 10,000) ----------- 1.0 g / L

      [Reducing agent solution]

  Sodium borohydride ------------------------ - 0.01 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C of pH 4.0 and stirred for 60 minutes.

The average diameter of the copper colloid particles produced was about 30 nm.

(7) Example 7 (modification of colloidal stabilizer of Example 1, change of amount, change of pH, addition of surfactant to catalyst solution)

Based on the above Example 1, except that the adsorption-promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, a copper colloid catalyst solution (except for the pH condition) and the method of producing the electroless copper- The processing conditions of the process were the same as those in Example 1.

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: colloid stabilizer = 1: 3.5, copper salt: reducing agent = 1: 1

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Lauryldimethylaminoacetic acid betaine --------------- 5 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Gluconic acid --------------------------------- 0.7 mol / L

  Polyoxyethylene-styrenated phenyl ether (EO 10 moles) ------ 0.2 g / L

      [Reducing agent solution]

  Sodium borohydride ------------------------ - 0.2 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 3.0 and stirred for 45 minutes.

The average diameter of the copper colloid particles produced was about 17 nm.

(8) Example 8 (Example of changing the amount of colloidal stabilizer in Example 1)

Based on the above Example 1, except that the adsorption-promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, a copper colloid catalyst solution (except for stirring time) or a method of producing electroless copper- The processing conditions of the process were the same as those in Example 1.

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: colloid stabilizer = 1: 3, copper salt: reducing agent = 1: 1

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Lauryldimethylbenzylammonium chloride --------------- 5 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Glycolic acid --------------------------------- 0.6 mol / L

      [Reducing agent solution]

  Sodium borohydride ------------------------ - 0.2 mol / L

The reducing agent solution was added dropwise to a copper solution having a pH of 4.0 at 25 占 폚 and stirred for 90 minutes.

The average diameter of the copper colloid particles produced was about 15 nm.

(9) Example 9 (Change of reducing agent in Example 1, change in plating bath temperature)

Based on the above Example 1, except that the adsorption-promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the copper colloid catalyst solution (except for the solution temperature condition of the copper solution) and the preparation of the electroless copper plating solution The method and the treatment conditions of each step were the same as those of Example 1.

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: Colloidal stabilizer = 1: 3, Copper salt: Reducing agent = 1: 0.5

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Quaternary ammonium salt of diarylamine polymer --------------- 5 g / L

  Polyoxyalkylene branched decyl ether ----------------- 1 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Citric acid ----------------------------------- 0.6 mol / L

  Polyvinylpyrrolidone (molecular weight 300,000) -------------- 1.0 g / L

      [Reducing agent solution]

  Dimethylamine borane 0.1 mol / L

The reducing agent solution was added dropwise to the copper solution at 35 DEG C adjusted to pH 4.0 and stirred for 45 minutes.

The average diameter of the copper colloid particles produced was about 45 nm.

(10) Example 10 (Example of soluble copper salt modification of Example 9)

Based on the above Example 1, except that the adsorption promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the copper colloid catalyst solution (except for the pH and the solution temperature condition of the copper solution) and the electroless copper solution amount And the processing conditions of each step were the same as those in Example 1. [

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: colloidal stabilizer = 1: 4, copper salt: reducing agent = 1: 0.5

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Lauryldimethylbenzylammonium chloride --------------- 5 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper methanesulfonate (as Cu ^{2 +} ) - 0.2 mol / L

  Citric acid ----------------------------------- 0.8 mol / L

      [Reducing agent solution]

  Dimethylamine borane 0.1 mol / L

The reducing agent solution was added dropwise to a copper solution having a pH of 3.0 at 35 DEG C and stirred for 45 minutes.

The average diameter of the copper colloid particles produced was about 16 nm.

(11) Example 11 (Example of soluble copper salt modification of Example 9)

Based on the above Example 1, except that the adsorption promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the copper colloid catalyst solution (except for the pH and the solution temperature condition of the copper solution) and the electroless copper solution amount And the processing conditions of each step were the same as those in Example 1. [

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: colloidal stabilizer = 1: 3.5, copper salt: reducing agent = 1: 0.75

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Quaternary ammonium salt of diarylamine polymer --------------- 5 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper citrate 2.5 Hydrate (as Cu ^{2 +} ) ---------------- 0.2 mol / L

  Citric acid ----------------------------------- 0.7 mol / L

      [Reducing agent solution]

  Dimethylamine borane 0.15 mol / L < RTI ID = 0.0 >

The reducing agent solution was added dropwise to a copper solution having a pH of 5.0 at 35 占 폚 and stirred for 45 minutes.

The average diameter of the copper colloid particles produced was about 14 nm.

(12) Example 12 (Example of modification of colloidal stabilizer of Example 9)

Based on the above Example 1, except that the adsorption-promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the copper colloid catalyst solution (except for the solution temperature condition of the copper solution) and the preparation of the electroless copper plating solution The method and the treatment conditions of each step were the same as those of Example 1.

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: colloidal stabilizer = 1: 2, copper salt: reducing agent = 1: 0.5

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Lauryldimethylaminoacetic acid betaine -------------- 5 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Gluconic acid --------------------------------- 0.4 mol / L

      [Reducing agent solution]

  Dimethylamine borane 0.1 mol / L

The reducing agent solution was added dropwise to the copper solution at 35 DEG C adjusted to pH 4.0 and stirred for 45 minutes.

The average diameter of the copper colloid particles produced was about 20 nm.

(13) Example 13 (when a water-soluble polymer is added)

Based on the above Example 1, except that the adsorption promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the production method of the copper colloid catalyst solution or the electroless copper plating solution and the treatment conditions of each step were the same as in Example 1 .

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: colloidal stabilizer = 1: 4, copper salt: reducing agent = 1: 1

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Quaternary ammonium salt of diarylamine polymer --------------- 5 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Citric acid ----------------------------------- 0.8 mol / L

  Polyethyleneimine ---------------------------- 1.5g / L

      [Reducing agent solution]

  Sodium borohydride - 0.2 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 4.0 and stirred for 45 minutes.

The average diameter of the copper colloid particles produced was about 17 nm.

(14) Example 14 (when a water-soluble polymer is added)

Based on the above Example 1, except that the adsorption promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the production method of the copper colloid catalyst solution or the electroless copper plating solution and the treatment conditions of each step were the same as in Example 1 .

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: colloidal stabilizer = 1: 4, copper salt: reducing agent = 1: 1

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Quaternary ammonium salt of diarylamine polymer --------------- 5 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Citric acid ----------------------------------- 0.8 mol / L

  Polyvinylpyrrolidone (molecular weight 300,000) -------------- 1.0 g / L

      [Reducing agent solution]

  Sodium borohydride - 0.2 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 4.0 and stirred for 45 minutes.

The average diameter of the copper colloid particles produced was about 15 nm.

(15) Example 15 (soluble copper salt change, addition of water-soluble polymer)

Based on the above Example 1, except that the adsorption promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the production method of the copper colloid catalyst solution or the electroless copper plating solution and the treatment conditions of each step were the same as in Example 1 .

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: colloidal stabilizer = 1: 4, copper salt: reducing agent = 1: 1

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Quaternary ammonium salt of diarylamine polymer --------------- 5 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper acetate monohydrate (as Cu ^{2 +} ) --------------- 0.2 mol / L

  Citric acid ----------------------------------- 0.8 mol / L

  Polyacrylamide --------------------------- 0.5 g / L

      [Reducing agent solution]

  Sodium borohydride - 0.2 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 4.0 and stirred for 45 minutes.

The average diameter of the copper colloid particles produced was about 22 nm.

(16) Example 16 (Example of raising the pH of Example 1)

Based on the above Example 1, except that the adsorption-promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, a copper colloid catalyst solution (except for the pH condition) and the method of producing the electroless copper- The processing conditions of the process were the same as those in Example 1.

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: Colloidal stabilizer = 1: 3, Copper salt: Reducing agent = 1: 0.5

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Quaternary ammonium salt of diarylamine polymer --------------- 5 g / L

  Polyoxyalkylene branched decyl ether ---------------- 1 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Ethylene diamine tetraacetic acid - 0.6 mol / L

  Polyvinylpyrrolidone (molecular weight 300,000) -------------- 1.0 g / L

      [Reducing agent solution]

  Sodium borohydride 0.1 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at pH 9.0 and stirred for 45 minutes.

The average diameter of the copper colloid particles produced was about 18 nm.

(17) Example 17 (Example of raising the pH of Example 1)

Based on the above Example 1, except that the adsorption-promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, a copper colloid catalyst solution (except for the pH condition) and the method of producing the electroless copper- The processing conditions of the process were the same as those in Example 1.

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: colloidal stabilizer = 1: 4, copper salt: reducing agent = 1: 1

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Quaternary ammonium salt of diarylamine polymer -------------- 5g / L

  Polyoxyalkylene branched decyl ether ---------------- 1 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Nitrilotriacetic acid ----------------------- 0.8 mol / L

  Polyacrylamide - 1.0 g / L

      [Reducing agent solution]

  Dimethylamine borane 0.2 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 10.0 and stirred for 45 minutes.

The average diameter of the copper colloid particles produced was about 15 nm.

(18) Example 18 (Example of raising the pH of Example 1)

Based on the above Example 1, except that the adsorption-promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, a copper colloid catalyst solution (except for the pH condition) and the method of producing the electroless copper- The processing conditions of the process were the same as those in Example 1.

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: Colloidal stabilizer = 1: 3, Copper salt: Reducing agent = 1: 0.5

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Quaternary ammonium salt of diarylamine polymer -------------- 5g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Diethylene triamine pentaacetic acid - 0.6 mol / L

      [Reducing agent solution]

  Sodium borohydride 0.1 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 10.0 and stirred for 45 minutes.

The average diameter of the copper colloid particles produced was about 20 nm.

(19) Comparative Example 1 (when the stabilizer is not present in the catalyst liquid)

Based on the above Example 1, except that the adsorption promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the production method of the copper colloid catalyst solution or the electroless copper plating solution and the treatment conditions of each step were the same as in Example 1 .

The mole ratio of each component of the catalyst solution is as follows.

Copper salt: colloidal stabilizer = 1: 0, copper salt: reducing agent = 1: 1

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Quaternary ammonium salt of diarylamine polymer -------------- 5g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

      [Reducing agent solution]

  Sodium borohydride - 0.2 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 4.0 and stirred for 45 minutes.

Copper colloidal particles were formed but aggregated and precipitated.

(20) Comparative Example 2 (when the ratio of copper to stabilizer is less than minimum)

Based on the above Example 1, except that the adsorption promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the production method of the copper colloid catalyst solution or the electroless copper plating solution and the treatment conditions of each step were the same as in Example 1 .

The molar ratio of each component of the catalyst solution is as follows.

Copper salt: colloid stabilizer = 1: 0.01, copper salt: reducing agent = 1: 1

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Quaternary ammonium salt of diarylamine polymer -------------- 5g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Citric acid ----------------------------------- 0.002 mol / L

      [Reducing agent solution]

  Sodium borohydride - 0.2 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 4.0 and stirred for 45 minutes.

Copper colloidal particles were formed but aggregated and precipitated.

(21) Comparative Example 3 (when the ratio of copper to stabilizer exceeds the maximum limit)

Based on the above Example 1, except that the adsorption promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the production method of the copper colloid catalyst solution or the electroless copper plating solution and the treatment conditions of each step were the same as in Example 1 .

The molar ratio of each component of the catalyst solution is as follows.

Copper salt: colloidal stabilizer = 1: 36, copper salt: reducing agent = 1: 1

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Quaternary ammonium salt of diarylamine polymer -------------- 5g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Lactic acid ------------------------------------ 7.2 mol / L

      [Reducing agent solution]

  Sodium borohydride - 0.2 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 4.0 and stirred for 45 minutes.

No copper colloid particles were produced.

(22) Comparative Example 4 (Example in which the surfactant was contained in the catalyst liquid of Example 1 in excess of the value specified in the present invention)

Based on the above Example 1, except that the adsorption promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the production method of the copper colloid catalyst solution or the electroless copper plating solution and the treatment conditions of each step were the same as in Example 1 .

The molar ratio of each component of the catalyst solution is as follows.

Copper salt: colloidal stabilizer = 1: 4, copper salt: reducing agent = 1: 1

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Quaternary ammonium salt of diarylamine polymer -------------- 5g / L

  Polyoxyalkylene branched decyl ether ---------------- 1 g / L

 (b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Citric acid ----------------------------------- 0.8 mol / L

  Polyoxyethylene-octyl phenyl ether (EO 15 moles) - 1.0 g / L

      [Reducing agent solution]

  Sodium borohydride - 0.2 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 4.0 and stirred for 45 minutes.

The average diameter of the copper colloid particles produced was about 15 nm.

(23) Comparative Example 5 (Example in which the catalyst liquid of Example 1 contains a large amount of surfactant)

Based on the above Example 1, except that the adsorption promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the production method of the copper colloid catalyst solution or the electroless copper plating solution and the treatment conditions of each step were the same as in Example 1 .

The molar ratio of each component of the catalyst solution is as follows.

Copper salt: colloidal stabilizer = 1: 4, copper salt: reducing agent = 1: 1

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Quaternary ammonium salt of diarylamine polymer -------------- 5g / L

  Polyoxyalkylene branched decyl ether ---------------- 1 g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Citric acid ----------------------------------- 0.8 mol / L

  Polyoxyethylene-octylphenyl ether (EO 15 moles) - 8.0 g / L

      [Reducing agent solution]

  Sodium borohydride - 0.2 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 4.0 and stirred for 45 minutes.

Copper colloidal particles were formed but aggregated and precipitated.

(24) Comparative Example 6 (Blank example without the adsorption promoting step in the process of Example 1)

As an example of omitting the adsorption promoting step on the basis of Example 1, except that the copper colloid catalyst solution was prepared with the following composition, the production method of the electroless copper plating solution and the treatment conditions of each step were the same as those of Example 1 .

The molar ratio of each component of the catalyst solution is as follows.

Copper salt: colloidal stabilizer = 1: 4, copper salt: reducing agent = 1: 1

(a) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Citric acid ----------------------------------- 0.8 mol / L

      [Reducing agent solution]

  Sodium borohydride - 0.2 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 4.0 and stirred for 45 minutes.

The average diameter of the copper colloid particles produced was about 17 nm.

 (25) Comparative Example 7 (Example in which gelatin is added to the catalyst liquid)

Based on the above Example 1, except that the adsorption promoting agent-containing liquid and the copper colloid catalyst solution were prepared in the following composition, the production method of the copper colloid catalyst solution or the electroless copper plating solution and the treatment conditions of each step were the same as in Example 1 .

The molar ratio of each component of the catalyst solution is as follows.

Copper salt: colloidal stabilizer = 1: 4, copper salt: reducing agent = 1: 1

(a) Preparation of adsorption accelerator-containing liquid

      [Content of Adsorption Accelerator]

  Quaternary ammonium salt of diarylamine polymer -------------- 5g / L

(b) Preparation of Copper Colloidal Catalyst Solution

      [Copper solution]

Copper sulfate (as Cu ^{2 +} ) ------------------------- 0.2 mol / L

  Citric acid ----------------------------------- 0.8 mol / L

  Gelatin ----------------------------------- 1.0 g / L

      [Reducing agent solution]

  Sodium borohydride - 0.2 mol / L

The reducing agent solution was added dropwise to a copper solution at 25 DEG C at a pH of 4.0 and stirred for 45 minutes.

Copper colloidal particles were formed but coagulated and precipitated.

≪ Example of stability stability test of catalyst liquid &

Herein, the copper colloid catalyst solutions prepared in Examples 1 to 18 and Comparative Examples 1 to 7 were evaluated for colloidal stability by the following criteria.

○: No sedimentation or decomposition occurred for one month after the bathing.

X: Precipitation or disintegration immediately after bathing.

≪ Evaluation test example of appearance evaluation of copper film deposited by electroless copper plating >

Next, with respect to the electroless copper plating film obtained by the electroless copper plating methods of Examples 1 to 18 and Comparative Examples 1 to 7, the superiority of the outer appearance of the coating film was visually evaluated on the basis of the following criteria.

◎: Copper plating film is uniform, and there is no unevenness.

○: The copper plating film was stained.

B: Partial precipitation (plating defect) was observed in the copper-plated film.

X: Copper film was not deposited.

Here, it is recognized that the " smudge " of the deposited film has a different portion from that of the surrounding, such as the denseness and smoothness of the film. The "smear" of the film is a view that is independent of the uniformity of the film.

≪ Test results on the stability of the copper colloid catalyst solution with respect to time and the outer appearance of the coating film &

Coating appearance Stability over time Coating appearance Stability over time Example 1 ◎ ○ Comparative Example 1 × × Example 2 ◎ ○ Comparative Example 2 × × Example 3 ○ ○ Comparative Example 3 × × Example 4 ◎ ○ Comparative Example 4 △ ○ Example 5 ◎ ○ Comparative Example 5 × ○ Example 6 ◎ ○ Comparative Example 6 △ ○ Example 7 ○ ○ Comparative Example 7 △ × Example 8 ◎ ○ Example 9 ◎ ○ Example 10 ◎ ○ Example 11 ◎ ○ Example 12 ○ ○ Example 13 ◎ ○ Example 14 ◎ ○ Example 15 ◎ ○ Example 16 ◎ ○ Example 17 ◎ ○ Example 18 ◎ ○

≪ Evaluation of aging stability of catalyst solution and appearance of plating film appearance >

In Comparative Example 1 except for the copper colloid catalyst solution colloid stabilizer, the stability of the catalyst solution with time was inferior. Therefore, even when electroless plating was performed on the non-conductive substrate after contact with the catalyst solution, there was no precipitation of the copper film.

When the relative amount of the colloidal stabilizer was too small in the ratio of the colloidal stabilizer and the copper salt, as shown in Comparative Example 2, the stability of the catalyst solution with the elapse of time was lowered, and thus the copper film was not precipitated by electroless plating. Even when the relative amount of the colloidal stabilizer was too large, as shown in Comparative Example 3, the stability of the catalyst solution with time deteriorated, and there was no precipitation of the copper film by electroless plating.

In Comparative Example 6 in which a non-conductive substrate was provided with a catalyst without an adsorption promoting treatment and the electroless copper plating was performed, the stability of the catalyst solution with respect to time was the same as in each Example. However, in the precipitated copper film, , It is understood that the catalytic activity is insufficient due to the absence of the adsorption promoting pretreatment before the application of the catalyst and the adsorption of the copper colloid particles on the substrate is inferior to that in the embodiment.

On the other hand, in Examples 1 to 18 in which electroless copper plating was carried out after the adsorption promoting pretreatment and after the catalyst imparting treatment, the stability of the catalyst solution with respect to time was good, and the copper film precipitated by electroless plating was largely uneven Uniformity was excellent.

Comparing Examples 1 to 18 with Comparative Example 1, it is understood that the colloidal stabilizer is required to be contained in the catalyst solution, not only the copper salt and the reducing agent, in order to obtain a copper film having no unevenness and excellent uniformity. Comparing Examples 1 to 18 with Comparative Examples 2 to 3, it is not sufficient to contain a colloidal stabilizer in order to obtain a copper film having no unevenness and excellent uniformity, and it is important to optimize the content ratio of the colloidal stabilizer and the copper salt Can be judged.

In Comparative Example 4 in which the surfactant contained the surfactant in an amount exceeding the inhibiting specified amount of the present invention 1, a "plating lack" in which part of the copper film deposited by the electroless plating occurred was recognized. In Comparative Example 5 in which the surfactant was contained in the catalyst solution more than Comparative Example 4, no copper film was precipitated by electroless plating. On the other hand, in Example 7 in which the surfactant was suppressed to a very small amount below the specified amount of the present invention 1, the copper film was smoothly precipitated without occurrence of plating failure or the like in the electroless plating (however, ). In Examples 1 to 4, Examples 8 to 12, and Example 18 in which the surfactant was not contained in the catalyst solution, copper coatings with no unevenness and excellent uniformity were naturally precipitated. That is, when the surfactant is added to the catalyst liquid in excess of the specified value of the present invention, the catalytic activity of the copper colloid catalyst solution is lowered, and plating failure occurs in the copper film obtained by the electroless plating. When the content of the surfactant is increased The copper film is smoothly precipitated only when the content of the surfactant is suppressed to a very small amount because the copper film is not precipitated due to the loss of the catalytic activity of the liquid. However, the higher the content of the surfactant in the catalyst liquid, , It can be judged that it is preferable to basically not add a surfactant in order to maintain the catalytic activity of the copper colloid catalyst liquid.

Further, in Comparative Example 7 in which gelatin, which is a representative example of a water-soluble polymer derived from natural origin, is contained in the catalyst liquid, stability with time of the catalyst liquid is lowered. As a result, in the electroless plating, a "plating lack" . On the other hand, in Examples 5 to 6 and Examples 13 to 17 in which a water-soluble polymer of a synthetic system was contained in the catalyst solution, copper coatings having no unevenness and excellent uniformity were precipitated. In order to obtain copper coatings of excellent practical level, It has been demonstrated that there is a need to choose polymers.

Next, Examples 1 to 18 will be examined in detail.

The relative evaluation with respect to the other embodiments will be described with reference to the first embodiment. First, in Example 1, a non-conductive substrate was preliminarily treated with an adsorption promoter containing a quaternary ammonium salt of a diallylamine polymer as a cationic surfactant, copper sulfate was used as a copper salt, sodium borohydride was used as a reducing agent, And the electroless copper plating is performed. The stability of the catalyst solution with respect to time is good, and precipitation does not occur or decomposition does not occur even after one month from the operation of the bath, and the electroless plating The copper film obtained in the above was excellent in uniformity and showed no precipitation unevenness.

Example 2 is an example in which the content of the colloidal stabilizer in the copper salt is lowered in Example 1, Example 4 is an example in which the content of the reducing agent is lowered in Example 1, Example 5 is an example in which the content of the reducing agent is increased Example 8 was an example in which the colloidal stabilizer was changed from citric acid to glycolic acid in Example 1, and the stability of the catalyst solution with respect to time and the appearance of the plated film were evaluated in the same manner as in Example 1, respectively.

Example 9 is an example in which the reducing agent is changed from sodium borohydride in Example 1 to dimethylamine borane and the temperature of the catalyst liquid is raised. Example 9 shows the stability of the catalyst solution over time and the appearance of the plated film in Example 1 . Example 10 is an example in which methanesulfonic acid is used as a copper salt, and Example 11 is an example in which copper chloride is used as a copper salt. The stability of the catalyst solution over time and the appearance of the plating film were evaluated in the same manner as in Example 1.

As described above, in Examples 1 to 4, Examples 8 to 12 and Example 18 in which the surfactant was not contained in the catalyst solution, the plating film was excellent in uniformity and no stain was observed. In Example 7 in which the surfactant was present in an extremely small amount of less than the specified amount of the present invention 1, the copper film was smoothly deposited without plating loss or the like in the electroless plating, but deposition irregularity was recognized in the film.

Example 5 containing PEG as the water-soluble polymer, PVP (average molecular weight of 40000), Example 6 containing PEG, Example 13 containing PEI, Examples 9 and 14 containing PVP (average molecular weight of 300000) In Example 15 containing PAM, the stability of the catalyst solution with respect to time and the appearance of the plated film were evaluated in the same manner as in Example 1, respectively.

In Example 1 where the catalyst solution was set to pH 4.0, the stability of the catalyst solution with respect to time and stability of the plating solution in Example 10 of pH 3, Example 11 of pH 5, Example 16 of pH 9 and Examples 17 to 18 of pH 10 The appearance was the same as in Example 1, respectively.

Claims (6)

An aqueous copper colloid catalyst solution for bringing a catalyst into contact with a non-conductive substrate to be subjected to electroless copper plating,
(A) a soluble copper salt,
(B) a reducing agent,
(C) oxycarboxylic acids and aminocarboxylic acids, wherein the molar ratio of the components (A) to (C) is in the range of A: C = 1: 0.03 to 1:35 In addition,
Without containing a surfactant,
A water-soluble polymer selected from polyethylene glycol, polypropylene glycol, polyvinyl pyrrolidone, polyvinyl alcohol, polyacrylamide, and polyethylene imine,
Without gelatin,
Without chlorine ions,
wherein the pH is 2 to 5 or 9 to 10. The aqueous copper-colloidal catalyst solution for electroless copper plating according to claim 1, The method according to claim 1,
Wherein the reducing agent (B) is at least one compound selected from the group consisting of a borohydride compound, an amine borane, a hypophosphorous acid, an aldehyde, an ascorbic acid, a hydrazine, a polyhydric phenol, a divalent naphthol, a phenolsulfonic acid, a naphthosulfonic acid and a sulfinic acid Wherein the copper-colloidal solution is at least one member selected from the group consisting of copper-colloid-based catalysts for electroless copper plating. The method according to claim 1,
Wherein the oxycarboxylic acids (C) are at least one selected from the group consisting of citric acid, tartaric acid, malic acid, gluconic acid, glycolic acid, lactic acid, trioxybutyric acid, isocitric acid, tartronic acid, glyceric acid, hydroxybutyric acid, Wherein the copper-colloidal solution is at least one member selected from the group consisting of citramalic acid and salts thereof. The method according to claim 1,
Wherein the aminocarboxylic acids (C) are selected from the group consisting of hydroxyethylethylenediaminetriacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, ethylenediaminetetraacetic acid, ethylenediaminetetrapropionic acid, nitrilotriacetic acid, iminodiacetic acid, hydroxyethyl Iminodiacetic acid, iminodipropionic acid, 1,3-propanediamine tetraacetic acid, 1,3-diamino-2-hydroxypropane tetraacetic acid, glycol ether diamine tetraacetic acid, metaphenylenediamine tetraacetic acid, 1,2- N, N-bis (2-hydroxyethyl) glycine, (S, N-diethylaminomethyl) glutamic acid, glutamic acid, dicarboxymethylglutamic acid, ornithine, cysteine, S) -ethylenediamine succinic acid and salts thereof. The electroless copper plating Aqueous copper colloid catalyst solution. (a) an adsorption promoting step (pretreatment step) for immersing a non-conductive substrate in a liquid containing at least one kind of an adsorption promoter selected from the group consisting of a nonionic surfactant, a cationic surfactant, an anionic surfactant and an amphoteric surfactant; ,
(b) a catalyst imparting step of immersing the non-conductive substrate in the aqueous copper colloid catalyst solution of claim 1 to adsorb copper colloid particles on the surface of the substrate, and
(c) an electroless plating step of forming a copper film on the substrate subjected to the adsorption treatment using an electroless copper plating solution. 6. The method of claim 5,
The electroless copper plating method characterized in that the adsorption promoter of the step (a) is a cationic surfactant and / or a amphoteric surfactant.