TWI734804B - Nickel colloidal catalyst solution for electroless nickel or nickel alloy plating and electroless nickel or a nickel alloy plating method - Google Patents

Abstract

The present invention provides an electroless nickel or a nickel alloy plating method comprising an adsorption-promoting process by immersing a non-conductive substrate in a solution containing a surfactant, a catalyst applying process by applying a nickel colloidal catalyst solution to the non-conductive substrate, and an electroless nickel plating process. The nickel colloidal catalyst solution comprises a soluble nickel salt (A), a reducing agent (B), and colloidal stabilizer (C) consisting of a specific saccharide such as glucose, fructose, sorbitol, xylitol, maltitol, mannitol and the like. A uniform nickel film without precipitated spot can be obtained by applying the adsorption-promoting process to enhance the catalyst activity, and implementing the catalyst giving process by nickel colloidal catalyst solution which is excellent in stability and reusability, and then applying electroless nickel plating process. Even the above mentioned method is used for nickel alloy plating method; an excellent and uniform nickle alloy film can be obtained.

Description

Nickel colloidal catalyst solution for electroless nickel or nickel alloy plating and method for electroless nickel or nickel alloy plating

The present invention relates to a nickel colloidal catalyst solution for catalyst application when electroless nickel or nickel alloy plating is performed on a non-conductive substrate, and an electroless plating method using the catalyst solution, providing excellent stability over time and good uniformity in appearance It has a nickel or nickel alloy film without streaks, and a catalyst solution that can improve the effectiveness of repeated use of the nickel colloidal catalyst solution by inserting a predetermined treatment before the catalyst is applied.

In order to represent glass-epoxy resin, glass-polyimide resin, epoxy resin, polyimide resin, polycarbonate resin, ABS resin, PET resin and other resin substrates, including glass substrates, ceramic substrates, etc. Electroless nickel or nickel alloy plating is carried out on the non-conductive substrate inside. The conventional method is: first make palladium, gold, silver, copper, nickel and other metals adsorb on the substrate to become a catalyst core, and then use the catalyst core to electroless nickel plating Or the nickel alloy liquid precipitates the nickel-based film on the substrate.

Therefore, when electroless plating including nickel plating or nickel alloy plating is performed, the prior art that imparts a nickel catalyst nucleus to the object to be plated as its pretreatment is listed below.

(1) Patent Document 1

The method of manufacturing a catalyst solution (the right column on page 1 and the upper right column on page 3) for the electroless plating of non-conductive substances (the scope of patent application items 1 to 6), the method uses a reducing agent (boron Hydrogen compound, dimethylamine borane) pair containing metal salt (nickel, cobalt or copper salt), dispersant (gelatin, non-ionic surfactant), complexing agent (monobasic acid, dicarboxylic acid, hydroxycarboxylic acid and The aqueous solution of its salt) is subjected to reduction treatment, and then stabilizers (hypophosphite, dimethylamine borane) are mixed.

Examples of the above-mentioned complexing agent include benzoic acid, succinic acid, lactic acid, and sodium acetate (page 3, upper left column).

In Examples 1 to 2, electroless nickel plating was performed after the nickel catalyst solution was prepared, but the complexing agent in the nickel catalyst solution was not disclosed.

In Example 3, after preparing the cobalt catalyst solution, electroless cobalt plating was performed, and the complexing agent of the cobalt catalyst solution was sodium acetate.

In Example 4, electroless copper plating was performed after the copper catalyst solution was prepared, but the complexing agent of the nickel catalyst solution was not disclosed.

(2) Patent Document 2

After attaching a metal catalyst core such as a palladium core to a substrate such as glass or ceramics (paragraph 48), use a chemical containing a predetermined alkylene diamine compound (ethylene diamine, N-hydroxymethyl ethylene diamine, etc., paragraph 20) The nickel plating solution is electrolessly plated.

The above-mentioned electroless nickel plating solution contains a reducing agent and a complexing agent (paragraph 28).

The complexing agent is dicarboxylic acid (succinic acid, maleic acid, malonic acid, etc.), hydroxycarboxylic acid (malic acid, lactic acid, citric acid, glycolic acid, gluconic acid, etc.), amino acids, etc. (paragraph 31). The complexing agent of the electroless nickel plating colloidal solution of the example is malic acid (Table 1).

The reducing agent is hypophosphorous acid, dimethylamine borane, etc. (paragraph 30).

(3) Patent Document 3

Colloidal catalysts for electroless nickel or copper plating (paragraphs 1, 9), stabilizers, reducing agents, metal salts (nickel, palladium, silver, gold, etc.) containing tertiary amine polymers and/or quaternary ammonium polymers ( The scope of application for patents item 1 to item 10).

However, specific examples of the colloidal catalyst liquid are palladium catalyst and silver catalyst liquid, and the nickel catalyst liquid is not disclosed (Table 1).

(4) Patent Document 4

A predetermined cationic surfactant such as amino carboxylate is adsorbed on the substrate on which the photoresist layer is formed to increase the affinity for the tin-palladium activator, and then the activator is used for activation treatment and electroless plating is performed nickel.

That is, a cationic surfactant is used in the preliminary step of applying a tin-palladium catalyst activation treatment to the substrate.

(5) Patent Document 5

In the case of using copper, silver, etc. to form the circuit conductor part of a multilayer ceramic substrate, it may cause short-circuit (migration) if charges are applied under high humidity. Therefore, it is best to use precious metals such as gold to form the conductor part. The palladium catalyst nucleus will not be substituted and precipitated on the precious metal, so it is impossible to electroless nickel plating on the precious metal (paragraph 4). However, the palladium catalyst nucleus can be given to the precious metal by treating the surface of the precious metal with an activation solution containing a complexing agent and aldehydes. Electroless nickel plating (items 1 to 4, paragraphs 5 to 6 of the scope of patent application).

The complexing agent of the above activation solution is polycarboxylic acid (succinic acid, malonic acid, gluconic acid, etc.), hydroxycarboxylic acid (malic acid, tartaric acid, citric acid, etc.), amino acids (glycine, alanine, etc.), amino carboxylic acid Acids (EDTA, etc.), etc. (paragraph 12).

The aldehydes of the activation solution are aldehyde-containing reducing sugars such as glucose and fructose, and aliphatic and aromatic aldehydes such as formaldehyde and benzaldehyde (paragraphs 19-20).

That is, it is characterized in that in the preliminary step of imparting a palladium catalyst nucleus to the substrate, an activation treatment is performed with aldehyde group-containing reducing sugars such as glucose and fructose.

Patent literature

Patent Document 1: Japanese Patent Application Laid-Open No. H02-093076

Patent Document 2: Japanese Patent Application Publication No. 2007-270344

Patent Document 3: Japanese Patent Application Laid-Open No. H11-209878

Patent Document 4: Japanese Patent Laid-Open No. H03-180476

Patent Document 5: Japanese Patent Laid-Open No. 2007-177268

Generally, a catalyst solution containing a soluble metal salt and a reducing agent is used in the pretreatment of electroless plating. The basic principle is to reduce the soluble metal salt to metal fine particles with a reducing agent, and the metal particles are used as the catalyst core for the plating. The actual situation is that most of the catalyst liquids of the above-mentioned Patent Documents 1 to 4 (However, Patent Document 4 is a tin-palladium catalyst, and Patent Document 2 does not describe specific catalyst cores other than palladium cores). For a long time, it can ensure the repeated continuity of the catalyst imparting and electroless plating operation smoothly.

When electroless nickel plating is performed after the catalyst is provided, although the stability over time after the catalyst solution is prepared is also important, especially when the electroless nickel plating operation is continuously performed, the deterioration caused by the repeated use of the catalyst solution also becomes a problem. Deterioration also causes the practical quality of the resulting electroless plating film to decrease.

As described above, if the catalyst solution has poor stability over time or low durability in repeated use, even if the nickel catalyst solution is used to apply catalyst to the non-conductive substrate and then electroless plating is performed, precipitation will be difficult and partial non-precipitation film will occur. Defects in the coating, or the coating film has streaks or poor uniformity.

The technical problem to be solved by the present invention is to improve the nickel catalyst liquid Stability over time and practicality of repeated use (repetitive use resistance), and electroless nickel plating (or nickel alloy) is applied to the non-conductive substrate after the catalyst has been applied to obtain a uniform and non-striking nickel-based film.

For example, the above-mentioned Patent Document 1 describes that a catalyst solution of nickel, cobalt, or copper for electroless plating contains monocarboxylic acid, dicarboxylic acid, hydroxycarboxylic acid, and salts thereof as a complexing agent. Examples of the complexing agent include benzoic acid and succinic acid. , Lactic acid, sodium acetate, etc. (right column on page 1, upper right column on page 3, upper left column on page 3).

Similarly, the applicant first proposed the use of nickel containing hydroxycarboxylic acid, aminocarboxylic acid, polycarboxylic acid and its salt as a colloidal stabilizer in Japanese Patent Application Laid-Open No. 2016-056421 (hereinafter referred to as the first application invention). After the catalyst solution is applied to the catalyst, the method of electroless nickel plating is carried out.

The present inventors focused on carbohydrates as compounds that replace these prescribed carboxylic acids, and conducted intensive studies on their suitability as colloidal stabilizers. As a result, they have newly discovered that the stability of the catalyst solution over time and the appearance of the coating film are new even in the nickel catalyst solution. The effectiveness of natural starch and chemical starch, which are representative examples of carbohydrates, cannot be confirmed. However, if a specific carbohydrate selected from sugar alcohols, monosaccharides, disaccharides, etc., which are also carbohydrates, it is shown to be similar to the above. The effectiveness of carboxylic acids is equivalent or better, especially in the case of continuous operation of electroless nickel plating, even if the nickel catalyst solution is repeatedly used, the durability is excellent and the effectiveness continues, and the present invention has been completed.

That is, the present invention 1 is a nickel colloidal catalyst solution for electroless nickel or nickel alloy plating, which is a nickel colloidal catalyst solution for catalyst application in contact with a non-conductive substrate subjected to electroless nickel or nickel alloy plating, and is characterized by , The nickel colloidal catalyst solution contains the following components: (A) soluble nickel salt; (B) reducing agent; and (C) selected from glucose, galactose, mannose, fructose, lactose, sucrose, maltose, palatinose, xylose, trehalose, sorbitol, xylitol, mannitol, maltose A colloidal stabilizer composed of at least one carbohydrate selected from alcohol, erythritol, reduced starch syrup, lactitol, reduced pilaginose, and gluconolactone.

The invention 2 is the nickel colloidal catalyst solution for electroless nickel plating or nickel alloy plating of the invention 1, characterized in that the content of the soluble nickel salt (A) is 0.005 mol/L~1.0 mol/L, and the reducing agent The content of (B) is 0.005 mol/L~0.8 mol/L, and the content of colloidal stabilizer (C) is 0.015 mol/L~8.0 mol/L.

The present invention 3 is the nickel colloidal catalyst solution for electroless nickel plating or nickel alloy plating of the foregoing invention 1 or 2, characterized in that the reducing agent (B) is selected from the group consisting of borohydride compounds, amine boranes, hypophosphorous acids, At least one of aldehydes, ascorbic acids, hydrazines, polyphenols, polynaphthols, phenolsulfonic acids, naphtholsulfonic acids, and sulfinic acids.

The present invention 4 is an electroless nickel or nickel alloy plating method, which is characterized in that the electroless nickel or nickel alloy plating method comprises the following steps: (S1) an adsorption promotion step (pretreatment step), immersing a non-conductive substrate in In the liquid of at least one of nonionic surfactants, cationic surfactants, anionic surfactants, and amphoteric surfactants; (S2) the catalyst imparting step, the non-conductive after adsorption promotion The flexible substrate is immersed in the nickel colloidal catalyst solution of any one of the inventions 1 to 3 above, so that the nickel colloidal particles are adsorbed on the surface of the substrate; and (S3) the electroless plating step, using electroless nickel or nickel alloy solution After the catalyst is provided, a nickel or nickel alloy film is formed on the above-mentioned substrate.

The present invention 5 is the electroless nickel or nickel alloy plating method of the above-mentioned present invention 4, and is characterized in that: After the adsorption promotion step (S1), there is a prepreg step (S12) before the catalyst imparting step (S2); in the above prepreg step (S12), the non-conductive substrate after the adsorption promotion is immersed in the prepreg, The prepreg liquid contains at least one of an acid, a reducing agent (B) in the nickel colloidal catalyst liquid component, and a colloidal stabilizer (C) in the nickel colloidal catalyst component.

The present invention 6 is the electroless nickel or nickel alloy plating method of the foregoing invention 4 or 5, characterized in that there is a reactivation step (S23) after the catalyst imparting step (S2) and before the electroless plating step (S3). In the reactivation step (S23), the non-conductive substrate provided with the catalyst is brought into contact with an acid-containing reactivation solution.

In the present invention, by making the nickel colloidal catalyst liquid contain a specific carbohydrate selected from sugar alcohols, monosaccharides, disaccharides, etc. as a colloidal stabilizer, compared with the case without the stabilizer or the case where starch is used as the stabilizer , The prepared initial catalyst solution has excellent stability over time, and by using the electroless nickel (or nickel alloy) plating of the initial catalyst solution, a uniform and streaked nickel or nickel alloy film can be obtained.

In addition, the present invention has a great advantage over the previous invention in terms of the appearance of a uniform film without streaks.

The above-mentioned Patent Document 5 describes the use of a precious metal such as gold to form the circuit conductor portion of a multilayer ceramic substrate, and an activation solution is used when electroless nickel plating is carried out after a palladium catalyst core is provided on the precious metal. The activation solution contains aldehydes selected from glucose and fructose Aldehydes such as reducing sugars, and complexing agents selected from hydroxycarboxylic acids and the like.

However, the above-mentioned activation solution is used in the preliminary step of imparting palladium catalyst nuclei to the substrate, and is not used in the catalyst imparting step.

That is, in the method of the present invention, a specific carbohydrate such as sugar alcohol is used for the catalyst imparting step itself, while the method described in Patent Document 5 uses aldehyde group-containing reducing sugars such as glucose and fructose. Classes and the like are used in the preliminary step instead of the catalyst imparting step, and are different from the present invention in this point.

In the electroless nickel (or nickel alloy) plating method of the present invention, the adsorption promotion step of immersing a non-conductive substrate in a surfactant-containing liquid is performed, and the catalyst imparting step using the nickel colloidal catalyst liquid of the present invention is performed. Electroless nickel plating (or nickel alloy), or adding a prepreg step of treatment with a prepreg solution containing acid and/or specific components contained in the nickel catalyst solution after the adsorption promotion step, and a catalyst imparting step Afterwards, in any one of the reactivation steps of treatment with an acid-containing reactivation solution, it is possible to obtain a nickel-based film with good appearance uniformity and no streaks.

In this case, the nickel colloidal catalyst solution of the present invention contains specific sugars in the colloidal stabilizer. Therefore, even if the catalyst solution is repeatedly used for electroless nickel plating (or nickel alloy), it can be uniform and practical without streaks. The appearance of the film has excellent resistance to repeated use.

Therefore, if the focus is on the effectiveness of electroless plating performed repeatedly using the nickel colloidal catalyst solution of the present invention, especially if it is outside the basic steps of adsorption promotion step (S1) → catalyst provision step (S2) → electroless plating step (S3) Adding the pre-impregnation step (S12) can prevent the mixing of surfactants and contamination of the nickel catalyst solution. Therefore, compared with the electroless plating treatment in which the prepreg step (S12) is omitted, the functional consumption (deactivation) of the catalyst liquid can be suppressed to improve the durability against repeated use, and a good film can be maintained even if the number of repeated uses of the catalyst liquid is increased. Exterior. That is, if the pre-dipping step (S12) is inserted into the electroless plating treatment including the above-mentioned basic steps, the repetition resistance of the catalyst solution of the present invention can be surely ensured, and the productivity of electroless plating can be improved.

In this case, the present invention using specific carbohydrates as a colloidal stabilizer is compared with the prior-application invention using prescribed carboxylic acids. Even if the pre-dipping step (S12) is omitted during electroless plating, the present invention can still play a better role than the prior-application invention. The addition of the prepreg step (S12) in the present invention has the same resistance to repeated use, and the present invention is better than the previous application in terms of the appearance of the resulting film. There are advantages.

Conversely, if the prepreg step (S12) is added when the catalyst solution of the present invention is used for electroless nickel (or nickel alloy) plating, it will be more reliable than the case where the same step (S12) was added in the previous invention. The advantage of improving the durability of the catalyst liquid of the present invention in repeated use.

The first aspect of the present invention is a nickel colloidal catalyst solution for electroless nickel plating (or nickel alloy), which is a nickel colloidal catalyst solution for catalyst application in contact with a non-conductive substrate, and contains (A) a soluble nickel salt, (B) reducing agent, (C) colloidal stabilizer composed of specific carbohydrates; the second aspect is the electroless nickel (or nickel alloy) plating method using the catalyst solution of the first aspect, which is preliminarily used with surfactants A method in which the non-conductive substrate is subjected to adsorption promotion treatment (S1) with the liquid of, and the catalyst is applied (S2) using the above-mentioned catalyst liquid, and then electroless plating (S3) is performed. In the electroless plating method of the second aspect described above, between the adsorption promotion step (S1) and the catalyst imparting step (S2), the substrate may be immersed in the reducing agent (B) containing acid, the catalyst liquid component, and the catalyst liquid The prepreg treatment (S12) in the prepreg of at least one of the colloidal stabilizers (C) in the components, and/or the immersion of the substrate in the prepreg between the catalyst provision step (S2) and the electroless plating step (S3) Reactivation treatment in acid-containing reactivation solution (S23).

In addition, the above-mentioned non-conductive substrates are represented by resin substrates such as glass-epoxy resin, glass-polyimide resin, epoxy resin, polyimide resin, polycarbonate resin, ABS resin, and PET resin, including glass Substrate, ceramic substrate, etc.

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

As long as the above-mentioned soluble nickel salt (A) is a soluble salt that generates nickel ions in an aqueous solution, any soluble salt can be used, and there is no particular limitation, and poorly soluble salts are not excluded. Specifically, nickel sulfate, nickel oxide, nickel chloride, nickel ammonium sulfate, nickel acetate, nickel nitrate, nickel carbonate, nickel sulfamate, or nickel salt of organic sulfonic acid or carboxylic acid, etc. can be mentioned.

Examples of the aforementioned reducing agent (B) include borohydride compounds, amine boranes, hypophosphorous acids, aldehydes, ascorbic acids, hydrazines, polyphenols, polynaphthols, phenol sulfonic acids, and naphthol sulfonic acids , Sulfinic acid, etc.

The borohydride compounds are sodium borohydride, potassium borohydride, etc., and the amine boranes are dimethylamine borane, diethylamine borane, and the like. Aldehydes are formaldehyde, glyoxylic acid or its salts, etc. Polyphenols are catechol, hydroquinone, resorcinol, pyrogallol, phloroglucinol, gallic acid, etc., phenol sulfonate The acids are phenol sulfonic acid, cresol sulfonic acid or a salt thereof.

The above-mentioned colloidal stabilizer (C) is a compound that forms a nickel complex in the plating bath, functions to ensure the stability of the catalyst solution over time, and is selected from specific carbohydrates.

Examples of the above-mentioned specific carbohydrates include: glucose, fructose, lactose, maltose, galactose, mannose, sucrose, trehalose, isomaltulose (palatinose) ), xylose, sorbitol, xylitol, mannitol, maltitol, erythritol, reduced starch syrup, lactitol, reduced isomaltulose (reduced palatinose), and gluconolactone.

The aforementioned glucose, fructose, xylose, etc. are monosaccharides, gluconolactone is a monosaccharide derivative, lactose, maltose, etc. are disaccharides, sorbitol, xylitol, mannitol, etc. are sugar alcohols, and the sugar used in the present invention Quality is a concept that includes the above-mentioned sugars, their derivatives, and sugar alcohols.

The above-mentioned reduced starch syrup refers to a substance obtained by reducing the aldehyde groups of specific above-mentioned sugars, such as glucose and maltose, to hydroxyl groups.

In addition, as the colloidal stabilizer (C), oligomers in which specific monosaccharides such as glucose, fructose, and xylose are polymerized by three or more glycosidic bonds are also effective.

On the other hand, as described above, the aforementioned colloidal stabilizer (C) is selected from specific carbohydrates, so starch (natural starch, chemical starch), dextrin, etc. are excluded.

Preferred carbohydrates include glucose, fructose, lactose, maltose, sorbitol, xylitol, mannitol, maltitol, lactitol, and gluconolactone. Sugar alcohols are generally suitable.

In the nickel colloidal catalyst liquid of the present invention, in order to increase the dispersibility of the fine metal used as the catalyst nucleus, a surfactant may be contained as necessary.

The surfactant can be selected from various nonionic, amphoteric, cationic, or anionic surfactants.

Examples of the above-mentioned nonionic surfactants include: C1~C20 alkanols, phenol, naphthol, bisphenols, (poly)C1~C25 alkylphenols, (poly)arylalkylphenols, C1~ C25 alkyl naphthol, C1~C25 alkoxylated phosphoric acid (salt), sorbitan ester, polyalkylene glycol, polyoxyalkylene alkyl ether, C1~C22 fatty amine , C1~C22 aliphatic amines, etc., addition condensates formed by the addition and condensation of 2 mol to 300 mol of ethylene oxide (EO) and/or propylene oxide (PO), etc.

Examples of the cationic surfactant include quaternary ammonium salts and pyridine salts. Specifically, ammonium salts of diallylamine polymers, lauryl trimethyl ammonium salts, and stearyl trimethyl ammonium can be cited. Salt, dodecyl dimethyl ethyl ammonium salt, octadecyl dimethyl ethyl ammonium salt, dodecyl dimethyl benzyl ammonium salt, cetyl dimethyl benzyl ammonium salt, Octadecyl dimethyl benzyl ammonium salt, trimethyl benzyl ammonium salt, triethyl benzyl ammonium salt, dimethyl diphenyl ammonium salt, benzyl dimethyl phenyl ammonium salt, hexadecane Pyridinium salt, lauryl pyridinium salt, dodecyl pyridinium salt, stearyl amine acetate, lauryl amine acetate, stearyl amine acetate and the like.

Examples of the above-mentioned anionic surfactants include alkyl sulfates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkyl phenyl ether sulfates, alkylbenzene sulfonates, [(mono, two, three ) Alkyl] naphthalene sulfonate and the like.

As said amphoteric surfactant, carboxybetaine, imidazoline betaine, sultaine, aminocarboxylic acid betaine, etc. are mentioned. In addition, a sulfated adduct or a sulfonated adduct of a condensation product of ethylene oxide (EO) and/or propylene oxide (PO) and alkylamine or diamine can also be used.

In the nickel colloidal catalyst liquid, the above-mentioned soluble nickel salt (A) can be used alone or in combination, and its content is suitably 0.005 mol/L~1.0 mol/L, preferably 0.01 mol/L~0.5 mol/L, More preferably, it is 0.02 mol/L to 0.3 mol/L.

If the content of the soluble nickel salt (A) is less than an appropriate amount, the thickness of the nickel film may be insufficient, or the uniformity of the film may decrease. On the contrary, the upper limit concentration is limited by the amount of dissolution.

In the catalyst liquid, the above-mentioned reducing agent (B) can be used alone or in combination, and its content is suitably 0.005 mol/L~0.8 mol/L, preferably 0.01 mol/L~0.5 mol/L, more preferably 0.02 mol/L~0.3 mol/L.

If the content of the reducing agent (B) is less than an appropriate amount, the reduction effect of the soluble nickel salt decreases. On the contrary, although the upper limit concentration is limited by the dissolved amount, if it is too large, the uniformity of the nickel film deposited by electroless plating may decrease.

In the catalytic liquid, the above-mentioned colloidal stabilizer (C) can be used alone or in combination, and its content is 0.015 mol/L~8.0 mol/L, preferably 0.03 mol/L~5.0 mol/L, more preferably 0.075~2.0 mol/L.

If the content of the colloidal stabilizer (C) is less than an appropriate amount, the stability of the colloidal catalyst solution over time or the resistance to repeated use may be impaired, and the uniformity of the resulting plating film may decrease, or streaking may occur. If it is greater than the appropriate amount, the uniformity of the nickel film obtained by electroless plating Sex may decline.

In addition, the colloidal stabilizer (C) is preferably at least 1.5 times the content of the soluble nickel salt (A).

The nickel colloidal catalyst liquid of the present invention may be an aqueous system or an organic solvent system such as a lipophilic alcohol.

In the case of an aqueous system, the solvent of the catalyst liquid is selected from water and/or hydrophilic alcohol.

In addition, the pH of the catalyst liquid is not particularly limited, and neutral, weakly acidic, weakly alkaline, etc. can be selected, and the pH is preferably 1 to 8, and more preferably pH 2 to 6.

When preparing the catalyst solution, in order to smoothly supply electrons from the reducing agent to the nickel ions, it basically takes time to slowly drop the reducing agent solution into a solution containing a soluble nickel salt (and a colloidal stabilizer) for preparation. For example, drop a reducing agent solution of 5°C to 70°C (preferably 10°C to 50°C, more preferably 10°C to 40°C) into the nickel salt solution and stir for 20 minutes to 1200 minutes (preferably 30 minutes to 300 minutes) ) To make a catalyst liquid. It should be noted that in the preparation of the catalyst liquid of the present invention, it is not excluded that the soluble nickel salt solution is dropped into the reducing agent liquid.

In the catalyst solution of the present invention, the nickel colloidal particles produced from the soluble nickel salt through the action of the reducing agent have an appropriate average particle size of 1 nm to 250 nm, preferably 1 nm to 120 nm, more preferably 1 nm to 100 nm, and even more preferably 1 nm. 60nm fine particles.

If the average particle size of the nickel colloidal particles is 250nm or less, it can be inferred that when the non-conductive substrate is immersed in the catalyst solution, the colloidal particles enter the recesses of the fine uneven surface of the substrate and are anchored by dense adsorption or catching. It promotes the imparting of nickel colloidal nuclei to the surface of the substrate.

The present invention 4 is an electroless plating method using the above-mentioned nickel colloidal catalyst solution, based on the sequential combination of the following three steps.

(S1) Adsorption promotion step

(S2) Catalyst imparting step

(S3) Electroless plating step (electroless nickel or nickel alloy plating step).

The adsorption promotion step (S1), in other words, is the pretreatment step of the catalyst imparting step (S2), in which a non-conductive substrate is immersed in a non-ionic surfactant, cationic surfactant, anionic surfactant. , And the step of at least one of the amphoteric surfactants in the liquid of the adsorption promoter, by contacting the substrate with the liquid containing the surfactant, the wettability of the substrate surface is improved, the catalyst activity is enhanced, and the nickel colloid in the next step is promoted Adsorption of particles.

In the adsorption promotion step, the non-conductive substrate needs to be brought into contact with the surfactant-containing liquid. Therefore, the substrate is basically immersed in the liquid. However, the surfactant-containing liquid may be sprayed on the substrate or coated with a brush. Layout on the substrate and so on.

From the viewpoint of promoting adsorption, positively charged cationic surfactants or amphoteric surfactants are suitable, and cationic surfactants are particularly preferred. In addition, if a small amount of nonionic surfactant is used in combination with a cationic surfactant, the adsorption promotion effect is further enhanced.

In the catalyst solution of the present invention 1, the zeta potential of the nickel colloidal particles generated by the reducing agent acting on the soluble nickel salt is negative. Therefore, if the non-conductive substrate is contacted with, for example, a cationic surfactant, the substrate tends to be positive. Charge, the adsorption efficiency of the nickel colloidal particles to the substrate in the next step increases.

Specific examples of the surfactant in the adsorption promotion step are as shown in the description of the surfactant described in the catalyst liquid of the present invention 1 above.

The content of the surfactant is 0.05 g/L to 100 g/L, preferably 0.5 g/L to 50 g/L. The treatment temperature of the adsorption promotion step is 5°C to 70°C, preferably 10°C to 40°C, and the immersion time is preferably about 0.5 minutes to 20 minutes.

It should be noted that before the adsorption promotion step (S1), it is preferable to further perform pretreatments such as degreasing treatment, desmear treatment, and neutralization treatment.

After completing the adsorption promotion step (S1), the non-conductive substrate is washed with pure water, dried or not, and then transferred to the next catalyst imparting step (S2).

In the catalyst imparting step, the non-conductive substrate is immersed in the above-mentioned nickel colloidal catalyst liquid to adsorb the nickel colloidal particles on the surface of the substrate.

The temperature of the catalyst solution is 5°C to 95°C, preferably 10°C to 60°C, the immersion time is about 0.1 to 20 minutes, and the pH is 2 to 11. When performing the immersion treatment, just leave the substrate in a static state It suffices to be immersed in the catalyst liquid, but it can also be stirred or shaken.

The non-conductive substrate immersed in the catalyst solution is washed with pure water, dried or not, and then transferred to electroless plating (electroless nickel or nickel alloy plating step) (S3).

The electroless nickel plating or nickel alloy plating may be processed in the same manner as in the past, and there is no particular limitation. The temperature of the electroless nickel plating or nickel alloy solution is usually 15°C to 90°C.

The stirring of the electroless nickel plating or nickel alloy solution can be air stirring, rapid liquid flow stirring, mechanical stirring performed by stirring blades, etc.

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

The above-mentioned electroless nickel plating is substantially nickel-phosphorus plating or nickel-boron plating.

The above-mentioned electroless nickel alloy plating is nickel-cobalt alloy plating, nickel-tin alloy plating, nickel-tin-zinc alloy plating, and the like.

The known electroless nickel plating bath basically contains a soluble nickel salt and a reducing agent as main components, and contains various additives such as a complexing agent, a pH adjuster, and a reaction accelerator.

In electroless nickel plating, if a phosphorus-based reducing agent (for example, hypophosphite) is used, a nickel-phosphorus film is obtained, and if a boron-based reducing agent (for example, dimethylamine borane) is used, a nickel-boron film is obtained.

The soluble nickel salt is as shown in the description of the nickel colloidal catalyst liquid.

The above-mentioned complexing agent is specifically ammonia, ethylenediamine, pyrophosphate, succinic acid, citric acid, malic acid, lactic acid, acetic acid, ethylenediaminetetraacetic acid (EDTA), and the like.

On the other hand, the composition of the electroless nickel plating alloy liquid is basically the same as the composition of the electroless nickel plating liquid, and contains a soluble salt of the other metal that forms an alloy with nickel.

As described above, nickel alloys are exemplified by nickel-cobalt alloys, nickel-tin alloys, nickel-tin-zinc alloys, etc. Therefore, soluble salts of the other metal include stannous sulfate, stannous chloride, and stannous oxide. , Sodium stannate, stannous fluoroborate, stannous salts of organic sulfonic acid or sulfosuccinic acid; soluble cobalt salts such as cobalt sulfate, cobalt chloride, cobalt salts of organic sulfonic acid, zinc chloride, Soluble zinc salts such as zinc sulfate, zinc oxide, organic sulfonic acid or zinc salt of sulfosuccinic acid, etc.

On the other hand, in the electroless nickel or nickel alloy plating method of the present invention, a prepreg step (S12) may be inserted after the adsorption promotion step (S1) and before the catalyst imparting step (S2).

The pre-impregnation step (S12) is characterized in that the non-conductive substrate that has been promoted by adsorption is immersed in an acid, the reducing agent (B) in the nickel colloidal catalyst liquid component, and the colloidal stabilizer in the nickel colloidal catalyst liquid component. (C) At least one of the prepregs.

By this prepreg treatment, it is possible to prevent the surfactant used in the adsorption promotion step (S1) from mixing into and contaminating the catalyst solution in the next step, thereby deactivating the nickel colloidal particles. That is, for the auxiliary strengthening of the catalyst activity, the above-mentioned reactivation step (S23) is a post-assisted strengthening, and the prepreg step (S12) is a preliminary auxiliary strengthening.

Specifically, the acid, the reducing agent (B) or the above-mentioned specific carbohydrate, that is, the colloidal stabilizer (C) may be used alone, or two or more of the acid, the reducing agent (B), and the colloidal stabilizer (C) may be used The mixture is also effective.

As the above-mentioned acid, inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, phosphorous acid, hypophosphorous acid, and sulfamic acid; organic acids such as carboxylic acids such as organic sulfonic acid, acetic acid, formic acid, oxalic acid, tartaric acid, citric acid, and glyoxylic acid, can be used.

In the case of using acid alone in this pre-impregnation step (S12), the low concentration range is Yes, the concentration is 0.001 mol/L to 0.1 mol/L, preferably 0.002 mol/L to 0.05 mol/L. In addition, in the case of using the reducing agent (B) or the colloidal stabilizer (C) alone in the prepreg step (S12), the low concentration range is sufficient, and the concentration is 0.001 mol/L~0.1 mol/L , Preferably 0.002 mol/L to 0.05 mol/L. When two or more components are selected from the above three components and used together, such as acid and reducing agent (B), acid and colloidal stabilizer (C), etc., the concentration based on the above-mentioned single use concentration can also be applied.

The immersion time in this step (S12) is about 1 minute to 3 minutes, and the immersion temperature is 5°C to 50°C, preferably 10°C to 40°C.

In addition, in the electroless nickel or nickel alloy plating method of the present invention, a reactivation step (S23) may be inserted after the catalyst imparting step (S2) and before the electroless plating step (S3).

The reactivation step (S23) is characterized in that the non-conductive substrate to which the catalyst has been applied is brought into contact with an acid-containing reactivation solution. By contacting the substrate with an acid, the nickel oxide (oxide film) formed by the partial oxidation of the nickel colloidal particles can be dissolved with acid such as sulfuric acid, removed and regenerated, and the activity of the nickel colloidal particles can be sufficiently maintained.

As a result, compared with the case where there is no reactivation step (S23), the degree of activity imparted by the catalyst can be assisted afterwards, and it can be reliably applied to substrates with complex shapes of vias and through holes. Prevent the disadvantages of plating spots and wire breaks, and further improve the adhesion of the nickel-based coating.

In the reactivation step (S23), the concentration of the acid is 0.02 mol/L~1.5 mol/L, preferably 0.05 mol/L~1.0 mol/L. The acid can be sulfuric acid, hydrochloric acid, phosphoric acid, phosphorous acid, Inorganic acids such as hypophosphorous acid and sulfamic acid; organic acids such as carboxylic acids such as organic sulfonic acid, acetic acid, formic acid, oxalic acid, tartaric acid, citric acid, and glyoxylic acid.

The treatment temperature for reactivation is 5°C to 70°C, preferably 10°C to 40°C, and the treatment time is 0.1 minute to 20 minutes, preferably 0.2 minute to 10 minutes.

Therefore, in the electroless nickel (or nickel alloy) plating method of the present invention, the From the viewpoint of film appearance and repetitive usability, it is preferable to insert at least the prepreg step (S12) in addition to the basic steps of adsorption promotion step (S1) → catalyst provision step (S2) → electroless plating step (S3), and more preferably sequentially Five steps of adsorption promotion step (S1) → prepreg step (S12) → catalyst provision step (S2) → reactivation step (S23) → electroless plating step (S3) are implemented.

[Examples]

Hereinafter, examples of the electroless nickel (or nickel alloy) plating method including the preparation of the liquid containing the adsorption promoter, the nickel colloidal catalyst liquid, and the electroless nickel or nickel alloy plating liquid of the present invention will be described, and the description will be made in sequence : Test example of the time-dependent stability of the prepared initial nickel colloidal catalyst solution, the appearance evaluation test example of the nickel (or nickel alloy) film deposited by electroless plating using the catalyst solution, and the repeated use of the nickel colloidal catalyst solution An evaluation test example of usability and an appearance evaluation test example of a nickel (or nickel alloy) film deposited by electroless plating using the catalyst solution used repeatedly.

It should be noted that the present invention is not limited to the following embodiments and test examples, and can of course be modified arbitrarily within the scope of the technical concept of the present invention.

"Embodiments of Electroless Nickel and Nickel Alloy Plating Methods"

In the following Examples 1 to 33, Examples 23 to 24 are examples of electroless nickel-cobalt alloy plating methods, and other examples are examples of electroless nickel plating (specifically, nickel-phosphorus plating) methods.

The above-mentioned Example 1 is the pretreatment step of degreasing, decontamination and neutralization, and then the adsorption promotion step (S1)→pre-impregnation step (S12)→catalyst imparting step (S2)→reactivation step (S23)→chemical An example of the electroless nickel plating method of the whole step of the plating step (S3) is that the adsorption promoter of the adsorption promotion step (S1) is a mixture of cationic surfactant and nonionic surfactant, and the catalyst imparting step (S2) Nickel colloidal catalyst solution uses nickel sulfate as soluble nickel salt, borohydride compound as reducing agent, and sorbitol As an example of colloidal stabilizers.

The above-mentioned Examples 4 to 5, 10 to 14, 16, 21, 23, 25, 28, and 31 are examples based on this Example 1. That is, as shown below.

Examples 4 to 5 are examples of changing the content of soluble nickel salt (A)

Examples 10-12 are examples of changing the colloidal stabilizer (C)

Examples 13-14 are examples of changing the type of soluble nickel salt (A)

Example 16 is an example of changing the reducing agent (B)

Example 21 is an example of changing the type of adsorption promoter to using cationic surfactant alone

Example 23 is an example of changing the type of electroless plating bath from a nickel-phosphorus plating bath to a nickel-cobalt alloy plating bath

Example 25 is an example of omitting the reactivation step (S23)

Example 28 is an example where the prepreg step (S12) is omitted

Example 31 is an example of the basic electroless nickel plating method, that is, the adsorption promotion step (S1) → the catalyst imparting step (S2) → the electroless plating step (S3) (the prepreg step (S12) and the reactivation step (S23) are omitted Step example).

In addition, Example 2 is an example in which the colloidal stabilizer (C) of Example 1 is changed to maltitol, and Examples 6-7, 17, 19, 26, 29, and 32 are examples based on Example 2. That is, as shown below.

Examples 6-7 are examples of changing the content of colloidal stabilizer (C)

Example 17 is an example of changing the type of reducing agent (B)

Example 19 is an example in which the type of colloidal stabilizer (C) is changed to a combination of maltitol and the colloidal stabilizer of the previous invention, namely hydroxycarboxylic acid

Example 26 is an example where the reactivation step (S23) is omitted

Example 29 is an example where the prepreg step (S12) is omitted

Example 32 is an example of the basic electroless nickel plating method, that is, the adsorption promotion step (S1) → the catalyst provision step (S2) → the electroless plating step (S3).

Next, Example 3 is an example in which the colloidal stabilizer (C) of Example 1 is changed to mannitol. Examples 8-9, 15, 18, 20, 22, 24, 27, 30, and 33 are based on Example 3. As a basic example. That is, as shown below.

Examples 8-9 are examples of changing the content of reducing agent (B)

Example 15 is an example of changing the type of soluble nickel salt (A)

Example 18 is an example of changing the reducing agent (B)

Example 20 is an example in which the type of colloidal stabilizer (C) is changed to a combination of mannitol and the colloidal stabilizer of the previously applied invention, namely glycine

Example 22 is an example of changing the type of adsorption promoter to using amphoteric surfactant alone

Example 24 is an example of changing the type of electroless plating bath from a nickel-phosphorus plating bath to a nickel-cobalt alloy plating bath

Example 27 is an example in which the reactivation step (S23) is omitted

Example 30 is an example where the prepreg step (S12) is omitted

Example 33 is: the basic electroless nickel plating method, that is, the adsorption promotion step (S1) → catalyst Give an example of step (S2) → electroless plating step (S3).

On the other hand, the following reference examples and comparative examples 1 to 2 are based on the above-mentioned example 1, and the adsorption promotion step (S1) → the pre-impregnation step (S12) → the catalyst imparting step (S2) → An example of the entire step of the reactivation step (S23) → the electroless plating step (S3). That is, as shown below.

The standard example is an example in which the colloidal stabilizer (sorbitol) of Example 1 is changed to the colloidal stabilizer of the first invention, that is, hydroxycarboxylic acid (citric acid).

Comparative Example 1 is: the nickel colloidal catalyst solution in the catalyst imparting step (S2) of Example 1 Example with colloidal stabilizer

Comparative Example 2 is an example in which the colloidal stabilizer (sorbitol) in Example 1 is changed to a natural starch of the same carbohydrate.

(1) Example 1

In the electroless nickel plating method of the present invention, all steps are characterized in that the adsorption promotion step (S1) → the prepreg step (S12) → the catalyst imparting step (S2) → the reactivation step (S23) → the electroless plating step (S3) are carried out sequentially. This Example 1 is an example of further performing pretreatment steps of degreasing, decontamination (surface roughening) and neutralization before the adsorption promotion step.

(S0) As a pretreatment step of adsorption promotion pretreatment (degreasing/decontamination/neutralization step)

(a) Composition of degreasing liquid, decontamination treatment liquid, and neutralization treatment liquid

[Degreasing liquid]

Polyoxyalkylene tridecylether: 2g/L

[Decontamination treatment liquid]

Potassium permanganate: 50g/L

Sodium hydroxide: 20g/L

[Neutralization Treatment Solution]

Sulfuric acid: 50g/L

Oxalic acid: 10g/L

(b) Conditions for the above pretreatment

First, prepare a substrate obtained by dissolving and removing 35μm copper foil in a double-sided copper-clad glass-epoxy substrate (FR-4 manufactured by Matsushita Electric Works Co., Ltd., board thickness: 1.0mm) as a sample substrate. After being immersed in a degreasing solution at 40°C for 2 minutes, washed with pure water, immersed in the above-mentioned decontamination treatment solution at 80°C for 10 minutes, and washed with pure water. Then, it was immersed in a neutralization treatment solution at 40°C for 10 minutes, washed with pure water, and dried to dissolve and remove manganese adsorbed on the sample substrate.

(S1) Adsorption promotion step

(a) Composition of adsorption accelerator

[Liquid containing adsorption promoter]

Quaternary ammonium salt of diallylamine polymer: 5g/L

Polyoxyalkylene branched decylether: 1g/L

pH value (adjusted with sodium hydroxide): 12.0

(b) Conditions for adsorption promotion treatment

A liquid containing an adsorption promoter was prepared according to the above composition, and the sample substrate was immersed in the liquid containing the adsorption promoter at 50°C for 2 minutes, and washed with pure water.

(S12) Pre-impregnation step

(a) Composition of prepreg solution

[Pre-impregnated liquid]

Sulfuric acid: 0.01 mol/L

(b) Pre-impregnation conditions

A prepreg solution was prepared according to the above composition, and the sample substrate was immersed in the prepreg solution at 25° C. for 1 minute, without washing with water, and transferred to the catalyst imparting step.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (25°C) adjusted to pH 4.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 40 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Sorbitol: 0.20 mol/L

[Reducing agent solution]

Sodium borohydride: 0.06 mol/L

(b) Treatment conditions given by the catalyst

The sample substrate subjected to the prepreg treatment (S12) was immersed in the nickel catalyst solution under conditions of 25°C for 10 minutes, and washed with pure water.

(S23) Reactivation step

(a) Composition of reactivation solution

[Reactivation Solution]

Sulfuric acid: 0.15 mol/L

(b) Conditions for reactivation treatment

A reactivation solution was prepared according to the above composition, and the sample substrate subjected to the adsorption promotion treatment was immersed in the reactivation solution under conditions of 30°C for 1 minute, and washed with pure water.

(S3) Electroless plating steps

(a) Preparation of electroless nickel-phosphorus plating solution

The electroless nickel-phosphorus plating solution is bathed according to the following composition. In addition, the plating solution uses dilute sulfuric acid and optionally sodium hydroxide to adjust the pH value.

[Electroless nickel-phosphorus bath]

Nickel sulfate hexahydrate ( ^{calculated as Ni 2+} ): 5.6g/L

Sodium hypophosphite monohydrate: 30g/L

Succinic acid: 25.0g/L

Pure water: balance

pH value (20℃): 4.6

(b) Conditions for electroless nickel plating

Put the sample substrate subjected to the above reactivation treatment (S23) at 90°C for 20 minutes Under the conditions, it was immersed in the above-mentioned plating solution to perform electroless plating, and after forming a nickel-phosphorus film on the sample substrate, it was washed with pure water and dried.

(2) Example 2

Based on the above example 1, in addition to preparing the nickel colloidal catalyst solution according to the following composition, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the setting of the treatment conditions of each step (including the pre-impregnation and reactivation steps) It is the same as Example 1 (the same applies to the following Examples and Comparative Examples).

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 4.5 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 35 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Maltitol: 0.20 mol/L

[Reducing agent solution]

Sodium borohydride: 0.06 mol/L

(3) Example 3

Based on the above-mentioned Example 1, except that the nickel colloidal catalyst solution was prepared according to the following composition, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step were set to be the same as in Example 1.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 5.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle size of the produced nickel colloidal particles is About 30nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Mannitol: 0.20 mol/L

[Reducing agent solution]

Sodium borohydride: 0.06 mol/L

(4) Example 4

Based on the above-mentioned Example 1, except that the nickel colloidal catalyst solution was prepared according to the following composition, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step were set to be the same as in Example 1.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 4.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 40 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.05 mol/L

Sorbitol: 0.20 mol/L

[Reducing agent solution]

Sodium borohydride: 0.06 mol/L

(5) Example 5

Based on the above-mentioned Example 1, except that the nickel colloidal catalyst solution was prepared according to the following composition, the preparation methods of the nickel colloidal catalyst solution and the electroless plating-phosphorus-nickel solution, and the treatment conditions of each step were set to be the same as in Example 1.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 4.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 40 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.25 mol/L

Sorbitol: 0.20 mol/L

[Reducing agent solution]

Sodium borohydride: 0.06 mol/L

(6) Example 6

Based on Example 2 above, except that the nickel colloidal catalyst solution was prepared according to the following composition, the preparation methods of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step were set to be the same as in Example 2.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 4.5 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 35 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Maltitol: 0.10 mol/L

[Reducing agent solution]

Sodium borohydride: 0.06 mol/L

(7) Example 7

Based on the above example 2, except that the nickel colloidal catalyst was prepared according to the following composition Except for the liquid, the preparation method of the nickel colloidal catalyst liquid and the electroless nickel-phosphorus plating liquid, and the treatment conditions of each step were set to be the same as in Example 2.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 4.5 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 35 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Maltitol: 1.00 mol/L

[Reducing agent solution]

Sodium borohydride: 0.06 mol/L

(8) Example 8

Based on the above Example 3, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution and the treatment conditions of each step are set to be the same as in Example 3 except that the nickel colloidal catalyst solution is prepared according to the following composition.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 7.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 30 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Mannitol: 0.20 mol/L

[Reducing agent solution]

Sodium borohydride: 0.03 mol/L

(9) Example 9

Based on the above Example 3, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution and the treatment conditions of each step are set to be the same as in Example 3 except that the nickel colloidal catalyst solution is prepared according to the following composition.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 5.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 30 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Mannitol: 0.20 mol/L

[Reducing agent solution]

Sodium borohydride: 0.10 mol/L

(10) Example 10

Based on the above-mentioned Example 1, except that the nickel colloidal catalyst solution was prepared according to the following composition, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step were set to be the same as in Example 1.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 5.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 50 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Maltose: 0.20 mol/L

[Reducing agent solution]

Sodium borohydride: 0.05 mol/L

(11) Example 11

Based on the above-mentioned Example 1, except that the nickel colloidal catalyst solution was prepared according to the following composition, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step were set to be the same as in Example 1.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 4.5 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 45 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Trehalose: 0.30 mol/L

[Reducing agent solution]

Sodium borohydride: 0.06 mol/L

(12) Example 12

Based on the above-mentioned Example 1, except that the nickel colloidal catalyst solution was prepared according to the following composition, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step were set to be the same as in Example 1.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

Add the following reducing agent solution dropwise to the following nickel solution (30℃) adjusted to pH 4.0 and stir Stir for 45 minutes to make a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 55 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Gluconolide: 0.40 mol/L

[Reducing agent solution]

Sodium borohydride: 0.08 mol/L

(13) Example 13

Based on the above-mentioned Example 1, except that the nickel colloidal catalyst solution was prepared according to the following composition, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step were set to be the same as in Example 1.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 4.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 40 nm.

[Nickel Solution]

Nickel carbonate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Sorbitol: 0.20 mol/L

[Reducing agent solution]

Sodium borohydride: 0.06 mol/L

(14) Example 14

Based on the above-mentioned Example 1, except that the nickel colloidal catalyst solution was prepared according to the following composition, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step were set to be the same as in Example 1.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 5.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 40 nm.

[Nickel Solution]

Nickel sulfamate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Sorbitol: 0.20 mol/L

[Reducing agent solution]

Sodium borohydride: 0.06 mol/L

(15) Example 15

Based on the above Example 3, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution and the treatment conditions of each step are set to be the same as in Example 3 except that the nickel colloidal catalyst solution is prepared according to the following composition.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 7.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 30 nm.

[Nickel Solution]

Nickel sulfamate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Mannitol: 0.20 mol/L

[Reducing agent solution]

Sodium borohydride: 0.06 mol/L

(16) Example 16

Based on the above-mentioned Example 1, except that the nickel colloidal catalyst solution was prepared according to the following composition, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step were set to be the same as in Example 1.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 4.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 40 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Sorbitol: 0.20 mol/L

[Reducing agent solution]

Dimethylamine borane: 0.05 mol/L

(17) Example 17

Based on Example 2 above, except that the nickel colloidal catalyst solution was prepared according to the following composition, the preparation methods of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step were set to be the same as in Example 2.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 5.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 35 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Maltitol: 0.20 mol/L

[Reducing agent solution]

Hypophosphorous acid: 0.06 mol/L

(18) Example 18

Based on the foregoing Example 3, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution and the treatment conditions of each step are set to be the same as in Example 3 except that the nickel colloidal catalyst solution is prepared according to the following composition.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 5.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 30 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Mannitol: 0.30 mol/L

[Reducing agent solution]

Dimethylamine borane: 0.05 mol/L

(19) Example 19

Based on Example 2 above, except that the nickel colloidal catalyst solution was prepared according to the following composition, the preparation methods of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step were set to be the same as in Example 2.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 4.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 35 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni2 +} ): 0.10 mol/L

Maltitol: 0.20 mol/L

Glutaric acid: 0.10 mol/L

[Reducing agent solution]

Sodium borohydride: 0.06 mol/L

(20) Example 20

Based on the foregoing Example 3, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution and the treatment conditions of each step are set to be the same as in Example 3 except that the nickel colloidal catalyst solution is prepared according to the following composition.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 7.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 30 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Mannitol: 0.20 mol/L

Glycine: 0.10 mol/L

[Reducing agent solution]

Sodium borohydride: 0.06 mol/L

(21) Example 21

Based on the above-mentioned Example 1, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the processing conditions of each step are set to be the same as those of Example 1, except that the liquid containing the adsorption promoter is prepared according to the following composition. Average of the produced nickel colloidal particles The particle size is about 40 nm.

(S1) Adsorption promotion step

(a) Composition of adsorption accelerator

[Liquid containing adsorption promoter]

Dodecyl dimethyl benzyl ammonium chloride: 5g/L

(22) Example 22

Based on the above-mentioned Example 3, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step are set to be the same as those of Example 3 except that the liquid containing the adsorption promoter is prepared according to the following composition. The average particle diameter of the produced nickel colloidal particles was about 30 nm.

(S1) Adsorption promotion step

(a) Composition of adsorption accelerator

[Liquid containing adsorption promoter]

Dodecyl dimethyl aminoacetic acid betaine: 5g/L

(23) Example 23

Based on the above-mentioned Example 1, in addition to preparing the electroless nickel-cobalt alloy plating solution according to the following composition instead of the electroless nickel-phosphorus plating solution, the preparation methods of the nickel colloidal catalyst solution and the electroless plating solution, and the treatment conditions of each step are set to Example 1 is the same. The average particle diameter of the produced nickel colloidal particles was about 40 nm.

(S3) Electroless nickel plating step

(a) Preparation of electroless nickel-cobalt alloy bath

The electroless nickel-cobalt alloy plating bath is built according to the following composition. In addition, the bath uses sodium hydroxide and optionally dilute sulfuric acid to adjust the pH value.

[Chemical nickel-cobalt alloy plating solution]

Nickel chloride ( ^{calculated as Ni 2+} ): 1.5g/L

Cobalt chloride ( ^{calculated as Co 2+} ): 1.5g/L

Sodium tartrate: 78g/L

Hydrazine hydrochloride: 68g/L

Pure water: balance

pH value (20℃): 12.0

(24) Example 24

Based on the above-mentioned Example 3, in addition to preparing the electroless nickel-cobalt alloy plating solution according to the following composition instead of the electroless nickel-phosphorus plating solution, the preparation methods of the nickel colloidal catalyst solution and the electroless plating solution, and the treatment conditions of each step are set to Example 3 is the same. The average particle diameter of the produced nickel colloidal particles was about 30 nm.

(S3) Electroless plating steps

(a) Preparation of electroless nickel-cobalt alloy bath

The electroless nickel-cobalt alloy plating bath is built according to the following composition. In addition, the bath uses sodium hydroxide and optionally dilute sulfuric acid to adjust the pH value.

[Chemical Plating-Cobalt Alloy Nickel Solution]

Nickel chloride ( ^{calculated as Ni 2+} ): 1.5g/L

Cobalt chloride ( ^{calculated as Co 2+} ): 1.5g/L

Sodium tartrate: 78g/L

Hydrazine hydrochloride: 68g/L

Pure water: balance

pH value (20℃): 12.0

(25) Example 25

Based on the above-mentioned Example 1, except that the reactivation step (S23) is omitted, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the processing conditions of each step are set to be the same as those of Example 1. The average particle diameter of the produced nickel colloidal particles was about 40 nm.

(26) Example 26

Based on the above-mentioned Example 2, except that the reactivation step (S23) is omitted, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step are set to be the same as in the second embodiment. The average particle diameter of the produced nickel colloidal particles was about 35 nm.

(27) Example 27

Based on the above-mentioned Example 3, except that the reactivation step (S23) is omitted, the preparation methods of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step are set to be the same as those of the third embodiment. The average particle diameter of the produced nickel colloidal particles was about 30 nm.

(28) Example 28

Based on the above-mentioned Example 1, the preparation methods of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the processing conditions of each step are set to be the same as those of Example 1, except that the pre-dipping step (S12) is omitted. The average particle diameter of the produced nickel colloidal particles was about 40 nm.

(29) Example 29

Based on the above-mentioned Example 2, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the processing conditions of each step are set to be the same as in Example 2 except that the prepreg step (S12) is omitted. The average particle diameter of the produced nickel colloidal particles was about 35 nm.

(30) Example 30

Based on the above-mentioned Example 3, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the processing conditions of each step are set to be the same as those of the Example 3 except that the pre-impregnation step (S12) is omitted. The average particle diameter of the produced nickel colloidal particles was about 30 nm.

(31) Example 31

Based on the above-mentioned Example 1, except that the pre-impregnation step (S12) and the reactivation step (S23) are omitted, the preparation methods of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step are set to Example 1 is the same. The average particle diameter of the produced nickel colloidal particles was about 40 nm.

(32) Example 32

Based on the above-mentioned Example 2, in addition to omitting the pre-impregnation step (S12) and the reactivation step (S23), the preparation methods of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step are set to be implemented Example 2 is the same. The average particle diameter of the produced nickel colloidal particles was about 35 nm.

(33) Example 33

Based on the above-mentioned Example 3, in addition to omitting the pre-impregnation step (S12) and the reactivation step (S23), the preparation methods of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step are set to Example 3 is the same. The average particle diameter of the produced nickel colloidal particles was about 30 nm.

(34) Standard example

Based on the above-mentioned Example 1, except that the nickel colloidal catalyst solution was prepared according to the following composition, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step were set to be the same as in Example 1.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 5.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 60 nm.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Citric acid: 0.20 mol/L

[Reducing agent solution]

Sodium borohydride: 0.06 mol/L

(35) Comparative example 1

Based on the above-mentioned Example 1, except that the nickel colloidal catalyst solution was prepared according to the following composition, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step were set to be the same as in Example 1.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 5.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 105 nm, and they aggregated and precipitated after production.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

[Reducing agent solution]

Sodium borohydride: 0.20 mol/L

(36) Comparative Example 2

Based on the above-mentioned Example 1, except that the nickel colloidal catalyst solution was prepared according to the following composition, the preparation method of the nickel colloidal catalyst solution and the electroless nickel-phosphorus plating solution, and the treatment conditions of each step were set to be the same as in Example 1.

(S2) Catalyst imparting step

(a) Preparation of nickel colloidal catalyst liquid

The following reducing agent solution was dropped into the following nickel solution (30°C) adjusted to pH 5.0 and stirred for 45 minutes to prepare a nickel colloidal catalyst solution. The average particle diameter of the produced nickel colloidal particles was about 130 nm, and they aggregated and precipitated after production.

[Nickel Solution]

Nickel sulfate ( ^{calculated as Ni 2+} ): 0.10 mol/L

Natural starch (corn starch): 0.20 mol/L

[Reducing agent solution]

Sodium borohydride: 0.06 mol/L

For the foregoing Examples 1 to 33, Reference Examples, and Comparative Examples 1 to 2, the presence or absence of each step, the type of adsorption promoter (surfactant), the composition of the nickel colloidal catalyst solution (soluble nickel salt (A), reduction The types and contents of agent (B) and colloidal stabilizer (C)), the average particle size of nickel colloidal particles, and the types of electroless plating bath are summarized in Table 1, Table 2, and Table 3.

"Test Example of Time Stability of Nickel Colloidal Catalyst Liquid"

The nickel colloidal catalyst liquids of the above-mentioned Examples 1 to 33, the reference examples and the comparative examples 1 to 2 were prepared, and the prepared initial catalyst liquids were evaluated for their stability over time according to the following standards.

○: No precipitation or decomposition occurred within 1 month after bathing.

×: Precipitation or decomposition immediately after bathing.

"Test Example for Appearance Evaluation of Nickel and Nickel Alloy Film Deposited by Electroless Plating Using the Prepared Initial Nickel Colloidal Catalyst Solution"

Next, electroless nickel or nickel alloy plating was performed using the initially unused nickel colloidal catalyst solution prepared above. For the nickel or nickel alloy plating films obtained in Examples 1 to 33, Reference Examples and Comparative Examples 1 to 2, the following standards The appearance of the film was evaluated visually.

◎: The uniformity of the plating film is excellent, and no streaks appear.

○: A small amount of streaks appear in the coating film, but the uniformity is excellent, and there is no problem in the practicality of the coating film.

△: Partial non-precipitation (plating defects) in the plating film.

×: The plating film is not precipitated.

In the present invention, the evaluation of uniformity mainly focuses on the thickness of the film. Although the evaluation of mottles also considers compactness or smoothness, it mainly uses the presence or absence of changes in the color tone from the surroundings as an index.

"Test results of the time-dependent stability of the initial nickel colloidal catalyst solution and the appearance of the coating"

Table 4 below is the result of the evaluation test of the stability of the nickel colloidal catalyst solution over time and the appearance of the coating film.

"Comprehensive evaluation of the time-dependent stability of the initial nickel colloidal catalyst solution and the appearance of the coating"

The nickel colloidal catalyst solution of Comparative Example 1 lacking a colloidal stabilizer had poor stability over time, and therefore even if the catalyst solution was used for catalyst application and then electroless plating was performed, no nickel film was deposited.

In addition, the present invention is characterized in that the nickel colloidal catalyst liquid contains a specific carbohydrate as a colloidal stabilizer. However, even if the catalyst liquid of Comparative Example 2 which contains the same carbohydrate natural starch instead of the above specific carbohydrate, the stability remains over time. Very poor, so no nickel film was deposited during electroless plating.

On the other hand, the reference example is an example of a nickel colloidal catalyst liquid containing a hydroxycarboxylic acid as a colloidal stabilizer. Based on the above-mentioned prior-application invention, the stability of the catalyst liquid over time is less than that of Examples 1 to 33. The change, the appearance of the plating film obtained by electroless plating is not different from that of Examples 1 to 33.

In contrast, the catalyst was imparted using a catalyst solution that selected specific sugars such as sugar alcohols and monosaccharides as colloidal stabilizers. In Examples 1 to 33 where electroless nickel plating was performed, the stability of the catalyst solution over time was good, and the chemical None of the nickel or nickel alloy coatings deposited by the plating have streaks and are excellent in uniformity.

Comparing these Examples 1 to 33 with the above Comparative Example 1, it can be seen that in order to obtain a uniform nickel (or nickel alloy) film without streaks, the catalyst solution must contain soluble nickel salt and reducing agent. A colloidal stabilizer composed of carbohydrates.

In addition, comparing Examples 1 to 33 with Comparative Example 2 (using starch), it can be judged that in order to obtain a nickel (or nickel alloy) film with no streaks and excellent uniformity, the use of sugar as a colloidal stabilizer is not enough. It is necessary to choose to limit carbohydrates to specific carbohydrates such as sugar alcohols and monosaccharides.

Furthermore, it can be seen that with regard to the stability of the initial catalyst solution over time and the appearance of the plating film obtained by electroless nickel plating using the catalyst solution, compared to the standard example (based on the invention of the previous application) using hydroxycarboxylic acid as a colloidal stabilizer, The present invention with specific carbohydrates is equally effective.

On the other hand, similar to the above-mentioned Examples 1-22 and 25-33 (electroless nickel plating method), for Examples 23-24 of the electroless nickel-cobalt alloy plating method, the nickel alloy film obtained by electroless plating is also free of streaks and uniformity. The sex is excellent.

Thus, Examples 1 to 33 will be discussed in detail.

Based on Example 1, comparative evaluation with other examples will be described. First, in Example 1, the adsorption promoter in the adsorption promotion step is a mixture of cationic surfactants and nonionic surfactants, and the nickel colloidal catalyst solution in the catalyst imparting step uses nickel sulfate as the soluble nickel salt and borohydride compounds as the Examples of reducing agent and sorbitol used as colloidal stabilizer, the catalyst liquid has good stability over time, and no precipitation or decomposition occurs after one month after bathing. In addition, the nickel film obtained by electroless plating has no precipitation spots and is excellent in uniformity. .

Based on the above example 1, Examples 4 to 5 are examples of changing the content of soluble nickel salt, examples 10 to 12 are examples of changing the colloidal stabilizer, and examples 13 to 14 are examples of changing the type of soluble nickel salt. , Example 16 is an example of changing the reducing agent, Example 21 is an example where the adsorption promoter is changed to a cationic surfactant alone, and Example 23 is an example of changing the type of electroless plating bath from nickel-phosphorus plating bath to nickel -An example of a cobalt alloy plating bath, even if the type of colloidal stabilizer, reducing agent, soluble nickel salt, etc. is changed, the content of soluble nickel salt is changed within an appropriate range, or the type of surfactant used in the adsorption promotion step is changed Or change the type of the electroless plating bath from a nickel-phosphorus plating bath to a nickel-cobalt alloy plating bath, and the respective evaluations of the stability of the catalyst solution over time and the appearance of the plating film are the same as in Example 1.

In addition, for the steps of sequentially implementing the adsorption promotion step (S1) → prepreg step (S12) → catalyst provision step (S2) → reactivation step (S23) → electroless plating step (S3) Example 1, Example 25 is an example where the reactivation step (S23) is omitted, Example 28 is an example where the pre-impregnation step (S12) is omitted, and Example 31 is the implementation of the three basic steps, namely the adsorption promotion step (S1) → catalyst An example of the provision step (S2) → electroless plating step (S3) (an example of omitting the two steps of prepreg (S12) and reactivation (S23)), and even if the entire step is not implemented, the pretreatment step (S12) and/ Or in the reactivation step (S23), the evaluations of the stability of the catalyst solution over time and the appearance of the coating film were also the same as those of Example 1. From this point of view, it can be judged that in order to ensure the good stability of the catalyst solution over time and the appearance of the coating, it is sufficient to implement the basic three steps of adsorption promotion step (S1) → catalyst provision step (S2) → electroless plating step (S3) .

Example 2 is an example in which the colloidal stabilizer of Example 1 is changed to maltitol. Even if the type of colloidal stabilizer is changed, the evaluation of the temporal stability of the nickel colloidal catalyst solution and the appearance of the coating film is the same as that of Example 1. Examples 6-7, 17, 19, 26, 29, and 32 are examples based on Example 2. If these examples are analyzed in comparison with Example 2, even if the content of the colloidal stabilizer is changed within an appropriate range, Change the type of colloidal stabilizer, reducing agent, etc. or omit the pre-impregnation step (S12) and/or reactivation step (S23) without implementing all steps. The evaluation of the stability of the catalyst solution over time and the appearance of the coating is also carried out. Example 2 is the same.

Next, Example 3 is an example of changing the colloidal stabilizer of Example 1 to mannitol. Even if the type of colloidal stabilizer is changed, the evaluation of the stability of the nickel colloidal catalyst solution over time and the appearance of the coating is the same as that of Example 1. . Examples 8-9, 15, 18, 20, 22, 24, 27, 30, 33 are examples based on Example 3. If these examples are compared to Example 3, even if the colloidal stabilizer and reducing agent are changed , Soluble nickel salt, etc., change the content of the reducing agent within an appropriate range, change the surfactant used in the adsorption promotion step to an amphoteric surfactant, or change the type of electroless plating bath from nickel-phosphorus plating bath to nickel -Cobalt alloy plating bath, or skip the pre-dipping step (S12) and/or the reactivation step (S23) without performing all steps. The evaluation of the stability of the catalyst solution over time and the appearance of the coating film is also the same as in Example 3. .

As described above, the time-dependent stability of the initial nickel colloidal catalyst solution and the appearance of the plating film obtained by electroless nickel plating (or nickel alloy) using the catalyst solution were investigated.

Therefore, the following examines the durability resistance (repeated use resistance) that can ensure the effectiveness of the catalyst solution used repeatedly, and the use of the catalyst solution used repeatedly for electroless nickel plating (or nickel composite). Gold) appearance of the coating.

"Test Example of Repetitive Use Resistance of Nickel Colloidal Catalyst Liquid Used Repetitively"

For the nickel colloidal catalyst liquids prepared in the foregoing Examples 1 to 33, Reference Examples and Comparative Examples 1 to 2, the properties of the catalyst liquid when used repeatedly for a specific number of times were evaluated according to the following criteria.

○: The catalyst liquid did not precipitate or decompose even when the number of repeated uses reached 60 times.

△: When the number of repeated uses reaches 40 times, a small amount of turbidity occurs in the catalyst liquid.

×: The catalyst liquid precipitated or decomposed before the number of repeated uses reached 10 times.

"Test Example of Appearance Evaluation of Coating Film Deposited by Electroless Plating with Nickel Colloidal Catalyst Solution Used Repeatedly"

Electroless nickel or nickel alloy plating was performed with the nickel colloidal catalyst solution used repeatedly. For the nickel or nickel alloy plating films obtained in Examples 1 to 33, Reference Examples and Comparative Examples 1 to 2, the appearance of the film was visually evaluated according to the following standards.

However, for Examples 1 to 27, the durability of over 60 times or more was confirmed. Therefore, the electroless plating film was evaluated using the catalyst solution with 60 times of repeated use. Examples 28 to 33 and reference examples This is an evaluation when the catalyst liquid was used when the number of repeated uses was 40 times. In addition, in Comparative Examples 1 and 2, the nickel colloidal particles were formed immediately after the preparation, but later agglomerated and decomposed, so they were evaluated when the initial catalyst liquid was used.

◎: The uniformity of the plating film is excellent, and no streaks appear.

○: A small amount of streaks appear in the coating film, but the uniformity is excellent, and there is no problem in the practicality of the coating film.

△: Partial non-precipitation (plating defects) in the plating film.

×: The plating film is not precipitated.

"Test results of repeated use of nickel colloidal catalyst solution and coating appearance"

The following table 5 is the result of the evaluation test of the reusability of the nickel colloidal catalyst and the appearance of the coating

"Comprehensive evaluation of repetitive use resistance and coating appearance of nickel colloidal catalyst liquid used repeatedly"

The nickel colloidal catalyst liquid of Comparative Example 1 lacking a colloidal stabilizer produced nickel colloidal particles immediately after preparation, but then aggregated and precipitated. Therefore, although the catalyst was imparted and electroless plating was performed by using the catalyst solution initially prepared, the plating film was not deposited. In addition, the same result was obtained in Comparative Example 2 using a natural starch colloid stabilizer.

On the other hand, in the standard example (based on the invention of the above-mentioned prior application), which is an example of a nickel colloidal catalyst liquid using hydroxycarboxylic acids (prescribed carboxylic acids) as a colloidal stabilizer, the number of repeated uses is about 40 times and a small amount of precipitation is generated. , So use the catalyst liquid at the time of 40 repeated use for catalyst application After further electroless plating, although a small amount of streaks appeared on the nickel film, the uniformity was good and practicality was not problematic.

In contrast, it can be seen that specific carbohydrates such as sugar alcohols and monosaccharides are selected as colloidal stabilizers, and the adsorption promotion step (S1) → prepreg step (S12) → catalyst provision step (S2) → reactivation step (S23) →In Examples 1 to 24 of all the steps of the electroless plating step (S3), the nickel colloidal catalyst solution did not precipitate or decompose even when the number of repeated uses was 60 times, and the catalyst function was maintained well. Therefore, the nickel (nickel-cobalt alloy) film obtained after catalyst application with the catalyst solution used in 60 cycles and electroless plating is free of streaks and excellent in uniformity.

In addition, in Examples 25 to 27 in which the reactivation step (S23) was omitted from the above all steps, as with the above all steps, the nickel colloidal catalyst solution did not precipitate or decompose even when the number of repeated uses was 60 times. The nickel film has no streaks and excellent uniformity. In Examples 25-27, the pre-impregnation step (S12) was implemented after the adsorption promotion step (S1). Therefore, in the pre-impregnation step (S12), the surfactant used in the adsorption promotion step (S1) was prevented from mixing and contaminating the catalyst liquid. It is considered that this is the main reason why the repeated use resistance of the catalyst liquid can be ensured well.

Next, in Examples 28 to 33 in which the prepreg step (S12) or the prepreg step (S12) and the reactivation step (S23) were omitted without performing all the above steps, the number of repeated uses reached 40 times. A small amount of precipitation is generated at all times. After applying catalyst with the catalyst solution used for 40 times and then electroless plating, unlike the above-mentioned reference example, the nickel (nickel-cobalt alloy) film has good streak-free uniformity and can be maintained as in Example 1. ~27 Undifferentiated film appearance.

Based on the above points, it can be seen that in the embodiment of selecting specific sugars such as sugar alcohols and monosaccharides for the colloidal stabilizer of the nickel colloidal catalyst solution, the adsorption promotion step (S1) → the catalyst imparting step (S2) → electroless plating step is implemented (S3) The basic three steps, the durability of the nickel catalyst solution can be maintained up to about 40 times. In addition, if the prepreg step (S12) or the prepreg step (S12) and When the reactivation step (S23) is carried out for all the steps, the repetitive use resistance of the nickel catalyst solution is significantly improved. On the other hand, not only in the case of adding the prepreg step (S12) to the full step or the basic three steps, but in the case of only performing the basic three steps, the appearance of the film obtained by electroless plating is also good in terms of uniformity and no streaks (evaluation All are ◎).

In this case, the specific carboxylic acid is used as the standard of colloidal stabilizer of nickel catalyst liquid In the example (based on the invention of the previous application), even if the entire process is used, the nickel catalyst solution has a durability of about 40 times (evaluated as △), and the resulting film has good appearance uniformity, but in view of the occurrence of a small amount of streaking (evaluated as ○ ), in terms of the durability of the catalyst solution and the appearance of the film obtained by using the catalyst solution repeatedly, it should be noted that the above advantages of the present invention over the reference example are noted. That is, the nickel colloidal catalyst solution of the present invention can maintain the catalyst-providing ability for a long period of time even if it is repeatedly used. Therefore, it can be judged that the catalyst solution of the present invention has excellent operability when used for electroless nickel (or nickel alloy) plating.

It should be noted that comparing Examples 1 to 33, it can be judged that even if the content or type of colloidal stabilizer, reducing agent, soluble nickel salt, etc. is changed, the type of surfactant used in the adsorption promotion step can be changed. Ensure the resistance to repeated use.

Industrial availability

The nickel colloidal catalyst solution for electroless nickel or nickel alloy plating and the method for electroless nickel or nickel alloy plating of the present invention can be applied to electroless plating of non-conductive substrates.

Claims (4)

A colloidal nickel catalyst solution for electroless nickel or nickel alloy plating, which is a nickel colloidal catalyst solution used for catalyst application in contact with a non-conductive substrate on which electroless nickel or nickel alloy plating is performed. The nickel colloidal catalyst liquid of nickel or nickel alloy contains the following components: (A) soluble nickel salt; (B) reducing agent, which is at least one selected from borohydride compounds and amine boranes; and (C) selected from glucose , Galactose, mannose, fructose, lactose, sucrose, maltose, piratinose, xylose, trehalose, sorbitol, xylitol, mannitol, maltitol, erythritol, reduced starch syrup, lactitol, A colloidal stabilizer composed of at least one carbohydrate in reduced piradican and gluconolactone; wherein the content of the soluble nickel salt (A) is 0.005 mol/L~1.0 mol/L, and the reducing agent (B) The content of the colloidal stabilizer (C) is 0.005 mol/L~0.1 mol/L, and the content of the colloidal stabilizer (C) is 0.2 mol/L~8.0 mol/L. An electroless nickel or nickel alloy plating method, characterized in that the above electroless nickel or nickel alloy plating method comprises the following steps: (S1) an adsorption promotion step (pretreatment step), immersing a non-conductive substrate in a non-ionic type Surfactant, cationic surfactant, anionic surfactant, and amphoteric surfactant in the liquid of at least one adsorption promoter; (S2) catalyst imparting step, impregnating the non-conductive substrate after adsorption promotion In the above-mentioned nickel colloidal catalyst solution in the first item of the scope of patent application, the nickel colloidal particles are adsorbed on the surface of the substrate; and (S3) the electroless plating step, using electroless nickel or nickel alloy solution on the above-mentioned substrate after the catalyst is provided A nickel or nickel alloy film is formed. For example, the electroless nickel or nickel alloy plating method in the second item of the patent application is characterized in that there is a prepreg step (S12) after the adsorption promotion step (S1) and before the catalyst imparting step (S2); in the above prepreg step (S12) ), the non-conductive substrate promoted by adsorption is immersed in the prepreg In the liquid, the prepreg liquid contains at least one of an acid, a reducing agent (B) in the nickel colloidal catalyst liquid component, and a colloidal stabilizer (C) in the nickel colloidal catalyst liquid component. For example, the electroless nickel or nickel alloy plating method of item 2 or item 3 of the scope of patent application is characterized in that there is a reactivation step (S23) after the catalyst imparting step (S2) and before the electroless plating step (S3). In the above-mentioned reactivation step (S23), the non-conductive substrate provided with the catalyst is brought into contact with an acid-containing reactivation solution.