JP2011042836A - Catalyst residue removing agent for printed circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catalyst residue removing agent which achieves formation of an electroless nickel plating coating and is excellent in characteristics to form a good plating coating only on a conductive pattern section on a printed circuit board. <P>SOLUTION: The catalyst residue removing agent for the printed circuit board includes an alkylene diamine compound represented by general formula (I): R<SP>1</SP>R<SP>2</SP>N(CH<SB>2</SB>)<SB>n</SB>NR<SP>3</SP>R<SP>4</SP>[wherein, R<SP>1</SP>, R<SP>2</SP>, R<SP>3</SP>, and R<SP>4</SP>are the same or different and are each a hydrogen atom or a group -(R<SP>5</SP>O)<SB>m</SB>H (in formula, R<SP>5</SP>is a 1-5C straight chain or branched chain alkylene group, and m is an integer of 1-10), and n is 2 or 3]. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a catalyst residue remover for printed wiring boards and an electroless nickel plating method using the catalyst residue remover for printed wiring boards.

  Conventionally, electroless nickel / gold plating has been applied to wiring portions and terminal portions for surface treatment when soldering and bonding electronic components, particularly printed wiring boards and package substrates. For electroless nickel plating, electroless nickel-phosphorus alloy plating using hypophosphite as a reducing agent, electroless nickel-boron alloy plating using boron compound as a reducing agent, and the like are generally used. In this case, usually, after forming an electroless nickel plating film having a thickness of about 3 to 5 μm, a gold film of about 0.03 to 0.5 μm is formed by a displacement plating method.

  When performing electroless nickel plating on conductive parts such as pad parts, circuit parts, terminal parts, etc. formed of conductive materials such as copper and silver in printed wiring boards, that is, when conducting electroless nickel plating, palladium catalyst is usually applied. After that, electroless nickel plating is performed. In recent years, an electroless nickel / palladium / gold plating method in which electroless palladium plating is performed between electroless nickel and gold plating has also been proposed.

  However, when a palladium catalyst is applied to the pattern portion, the palladium catalyst may be adsorbed to a resin (eg, epoxy resin, polyimide resin, etc.), ceramic, glass, or the like that is a substrate of a printed wiring board. is there. The palladium catalyst adsorbed on the base material is slightly present as a residue even after washing with water. Therefore, when electroless nickel plating is performed, the electroless nickel plating reaction occurs not only in the pattern portion of the printed wiring board but also in the residue portion, resulting in abnormal deposition of electroless nickel plating deposited on the substrate. In addition, a bridging phenomenon in which the conductive pattern portions are connected by electroless nickel plating occurs.

  As a countermeasure against the problems such as abnormal precipitation and bridging phenomenon, for example, Japanese Patent Application Laid-Open No. 2008-101257 proposes a method of performing electroless nickel plating after treatment with a liquid containing hydrogen sulfate and metal chloride. Yes. However, although the above-mentioned problems are slightly improved in this treatment liquid, it is not sufficient, and industrial problems still remain.

JP 2008-101257 A

  The present invention has been made in view of the current state of the prior art described above, and its main purpose is excellent in characteristics that can form a good plating film only on the conductive pattern portion in a printed wiring board, that is, fine pattern properties. Another object of the present invention is to provide a catalyst residue remover that enables formation of an electroless nickel plating film.

  As a result of intensive studies to achieve the above-mentioned object, the present inventor has given an alkylenediamine compound represented by a specific general formula after imparting a catalyst for electroless plating to a conductive pattern portion of a printed wiring board. It has been found that the above-mentioned object can be achieved by contacting with the catalyst residue remover for printed wiring board contained, followed by electroless nickel plating, and the present invention has been completed here.

That is, this invention provides the electroless nickel plating method using the catalyst residue remover for printed wiring boards, and the catalyst residue remover for printed wiring boards.
1. The following general formula (I)

[Wherein R ¹ , R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom or the following group:

(Wherein R ⁵ is a linear or branched alkylene group having 1 to 5 carbon atoms, m is an integer of 1 to 10), and n is 2 or 3. ] The catalyst residue removal agent for printed wiring boards characterized by containing the alkylenediamine compound represented by these.
2. In alkylenediamine compound represented by the general formula ^{(I), R 1, R} 2, R 3 and at least one is a printed wiring board for catalyst residues according to item 1, wherein a hydrogen atom of the group represented by R ⁴ Remover.
3. Item ^{3. The} alkylene diamine compound represented by the general formula (I), wherein ^{1 to 3} of the groups represented by R ¹ , R ² , R ³ and R ⁴ are hydrogen atoms. Catalyst residue remover for printed wiring boards.
4). Item 4. The printed wiring board catalyst residue remover according to any one of Items 1 to 3, further comprising at least one compound selected from the group consisting of a cyanide compound and a thiocyanate.
5). Electroless nickel plating method including the following steps (i) to (iii):
(I) a step of applying a catalyst for electroless plating to a printed wiring board;
(Ii) A step of bringing the printed wiring board obtained in (i) into contact with the catalyst residue remover according to any one of Items 1 to 4,
(Iii) A step of performing electroless nickel plating on the printed wiring board obtained in (ii).

Hereinafter, the catalyst residue remover of the present invention will be described in detail.
Catalyst Residue Remover for Printed Wiring Board The catalyst residue remover of the present invention has the following general formula (I)

[Wherein R ¹ , R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom or the following group:

(Wherein R ⁵ is a linear or branched alkylene group having 1 to 5 carbon atoms, m is an integer of 1 to 10), and n is 2 or 3. The alkylenediamine compound represented by this is contained, It is characterized by the above-mentioned.

  According to the catalyst residue removing agent of the present invention, nickel having excellent fine pattern properties can be obtained by using the above-described alkylenediamine compound as an additive, compared with a nickel plating film formed by a conventional electroless nickel plating method. A plating film can be formed.

In the above general formula (I), R ⁵ is a linear or branched alkylene group having 1 to 5 carbon atoms. Specific examples thereof include straight chain such as methylene, ethylene, trimethylene, tetramethylene, pentamethylene and the like. Chain methylene; branched methylene such as isopropylene and isobutylene; and the like. Moreover, m is an integer of 1-10. Specific examples of m = 1 include linear or branched hydroxyalkyl groups having about 1 to 3 carbon atoms such as hydroxymethyl, hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl and the like. Can do. Hereinafter, in the present specification, it may be referred to as a hydroxyalkyl group including a case where m is 2 or more.

Specific examples of the compound having an ethylenediamine skeleton in which n = 2 among the above-described alkylenediamine compounds are as follows.
(1) Compounds in which R ¹ , R ² , R ³ and R ⁴ are all hydrogen atoms:
Ethylenediamine (2) A compound in which ^{three of} R ¹ , R ² , R ³ and R ⁴ are hydrogen atoms:
N-hydroxymethylethylenediamine N-hydroxyethylethylenediamine N-hydroxypropylethylenediamine N-hydroxyisopropylethylenediamine N-hydroxybutylethylenediamine (3) Compound in which ^{two of} R ¹ , R ² , R ³ and R ⁴ are hydrogen atoms :
N, N′-dihydroxymethylethylenediamine N, N′-dihydroxyethylethylenediamine N, N′-dihydroxypropylethylenediamine N, N′-dihydroxyisopropylethylenediamine N, N′-dihydroxybutylethylenediamine (4) R ¹ , R ² , R ^A compound in which one of ³ and R ⁴ is a hydrogen atom:
N, N, N′-trihydroxymethylethylenediamine N, N, N′-trihydroxyethylethylenediamine N, N, N′-trihydroxypropylethylenediamine N, N, N′-trihydroxyisopropylethylenediamine N, N, N ′ -Trihydroxybutylethylenediamine (5) Compound in which all of R ¹ , R ² , R ³ and R ⁴ are hydroxyalkyl groups:
N, N, N ′, N′-tetrahydroxymethylethylenediamine N, N, N ′, N′-tetrahydroxyethylethylenediamine N, N, N ′, N′-tetrahydroxypropylethylenediamine N, N, N ′, N '-Tetrahydroxyisopropylethylenediamine N, N, N', N'-tetrapolyhydroxypropyleneethylenediamine represented by the following formula (preferably having a molecular weight of about 760 to 770)

Moreover, the specific example of the compound which has the propanediamine skeleton which is n = 3 among the above-mentioned alkylene diamine compounds is as follows.
(1) Compounds in which R ¹ , R ² , R ³ and R ⁴ are all hydrogen atoms:
Propanediamine (2) A compound in which ^{three of} R ¹ , R ² , R ³ and R ⁴ are hydrogen atoms:
Two of the N- hydroxymethyl-propane diamine N- hydroxyethyl-propane diamine N- hydroxypropyl propanediamine N- hydroxyisopropyl propanediamine N- hydroxybutyl propanediamine ^{(3) R 1, R 2} , R 3 and ^{R 4} Compounds that are hydrogen atoms:
N, N′-dihydroxymethylpropanediamine N, N′-dihydroxyethylpropanediamine N, N′-dihydroxypropylpropanediamine N, N′-dihydroxyisopropylpropanediamine N, N′-dihydroxybutylpropanediamine (4) R ¹ , R ² , R ³ and R ⁴ , one of which is a hydrogen atom:
N, N, N′-trihydroxymethylpropanediamine N, N, N′-trihydroxyethylpropanediamine N, N, N′-trihydroxypropylpropanediamine N, N, N′-trihydroxyisopropylpropanediamine N, N, N′-trihydroxybutylpropanediamine (5) Compound in which all of R ¹ , R ² , R ³ and R ⁴ are hydroxyalkyl groups:
N, N, N ′, N′-tetrahydroxymethylpropanediamine N, N, N ′, N′-tetrahydroxyethylpropanediamine N, N, N ′, N′-tetrahydroxypropylpropanediamine N, N, N ', N'-tetrahydroxyisopropylpropanediamine N, N, N', N'-tetrapolyhydroxypropylenepropanediamine represented by the following formula

Among the above-mentioned alkylenediamine compounds, (1) R ¹ , R ² , R ³ and R ⁴ are all hydrogen atoms, (2) R ¹ , R ² , R ³ and R ⁴ Is a hydrogen atom, or (3) when ^{two of} R ¹ , R ² , R ^3, and R ⁴ are hydrogen atoms, the conductive pattern portion can be added even if the addition amount is small. It is preferable because the characteristic that can form a good plating film only on the surface, that is, the fine pattern property is good. Among the above-described alkylenediamine compounds, ethylenediamine, N-hydroxymethylethylenediamine, N-hydroxyethylethylenediamine, N, N′-dihydroxymethylethylenediamine, N, N′-dihydroxyethylethylenediamine, propanediamine, N-hydroxymethylpropanediamine, More preferably, it is at least one compound selected from the group consisting of N-hydroxyethylpropanediamine, N, N′-dihydroxymethylpropanediamine and N, N′-dihydroxyethylpropanediamine, and ethylenediamine, N-hydroxyethyl. A small amount selected from the group consisting of ethylenediamine, N, N′-dihydroxyethylethylenediamine, propanediamine and N, N′-dihydroxyethylpropanediamine. It is further preferred Kutomo which is a kind of compound.

  The above-mentioned alkylene diamine compounds can be used singly or in combination of two or more.

  In the catalyst residue remover of the present invention, the concentration of the alkylenediamine compound represented by the general formula (I) is usually about 1 to 500 g / L, preferably about 5 to 300 g / L, more preferably 10 to 150 g / L. Used as an aqueous solution to the extent.

  In the catalyst residue removing agent of the present invention, when at least one compound selected from the group consisting of a cyanide compound and a thiocyanate is added, the fine pattern property is further improved. Specific examples of the cyan compound include potassium cyanide, sodium cyanide, ammonium cyanide, calcium cyanide and the like. Specific examples of thiocyanate include potassium thiocyanate, sodium thiocyanate, and ammonium thiocyanate. Among at least one compound selected from the group consisting of the cyan compound and thiocyanate described above, it should be at least one compound selected from the group consisting of potassium cyanide, sodium cyanide, potassium thiocyanate and sodium thiocyanate. Preferably, it is at least one compound selected from the group consisting of sodium cyanide and potassium thiocyanate.

  At least one compound selected from the group consisting of the cyan compound and thiocyanate described above can be used singly or in combination of two or more.

  The blending amount of at least one compound selected from the group consisting of a cyanide compound and a thiocyanate is preferably about 0.001 to 100 g / L, more preferably 0.005 to 50 g / L. 1 to 20 g / L is more preferable.

  Moreover, surfactant can be mix | blended with the catalyst residue removal agent of this invention. As the surfactant, various surfactants such as anionic, nonionic, cationic, and amphoteric can be used singly or in combination of two or more.

  Examples of the anionic surfactant include lauric acid, myristic acid, palmitic acid, stearic acid, a carboxylic acid salt of 12 to 18 carbon atoms (sodium salt, potassium salt, etc.), 12 to 18 carbon atoms, and the like. N-acylamino acid, N-acylamino acid salt, polyoxyethylene alkyl ether carboxylate, carboxylate such as acylated peptide having 12 to 18 carbon atoms; alkylsulfonate, alkylbenzenesulfonate, alkylnaphthalenesulfonate Sulfonates such as naphthalene sulfonate formalin polycondensate, sulfosuccinate, α-olefin sulfonate, N-acyl sulfonate; sulfated oil, alkyl sulfate, alkyl ether sulfate, polyoxyethylene sulfate Salt, polyoxyethylene alkyl allyl ether sulfate, alkyl Sulfuric acid ester salts such as bromide sulfate; polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, can be used phosphoric acid ester salts such as alkyl phosphates and the like.

  Nonionic surfactants include, for example, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, alkylallyl formaldehyde condensed polyoxyethylene ether, polyoxyethylene polyoxypropylene block copolymer, polyoxyethylene polyoxypropyl alkyl ether, etc. Ether type surfactants; ether ester type surfactants such as polyoxyethylene glycerin fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene fatty acid alkanolamide sulfate; polyethylene glycol fatty acid ester, Ethylene glycol fatty acid ester, glycerin fatty acid ester, polyglycerin fatty acid ester, sorbi Ester-type surfactants such as fatty acid esters, propylene glycol fatty acid esters, and sucrose fatty acid esters; nitrogen-containing surfactants such as fatty acid alkanolamides, polyoxyethylene fatty acid amides, and polyoxyethylene alkylamines can be used. .

  As the cationic surfactant, for example, alkyltrimethylammonium chloride, dialkyldimethylammonium chloride, fatty acid amidoamine salt, ethyl lanolin sulfate fatty acid aminopropylethyldimethylammonium, dicocoylethylhydroxyethylammonium sulfate and the like can be used.

  As amphoteric surfactants, for example, alkyl betaine type surfactants, amidopropyl betaine type surfactants, imidazolinium betaine type surfactants, sulfobetaine type surfactants, phosphobetaine type surfactants, etc. should be used. Can do.

  When the surfactant is at least one selected from the group consisting of an anionic surfactant and a nonionic surfactant, it is preferable because there is no adverse effect such as a decrease in speed on the nickel plating reaction.

  As a compounding quantity of surfactant, it is preferable to set it as about 0.001-50 g / L, and it is more preferable to set it as about 0.005-20 g / L.

The pH of the catalyst residue remover of the present invention is not particularly limited, but is usually about 1 to 13, preferably about 3 to 11. For pH adjustment, inorganic acids such as sulfuric acid and phosphoric acid, sodium hydroxide, aqueous ammonia and the like can be used. However, when a cyan compound is blended, cyan gas is generated, so the pH is preferably 5 or more. Similarly, when thiocyanate is used, it is preferable that the pH is 5 or higher because thiocyanic acid is self-decomposed. In the case of a material weak in alkali resistance such as a solder resist, the pH is preferably 11 or less. When the pH is strong alkalinity of 13 or more, there is a high possibility that the adhesion of the solder resist is impaired.
Electroless Plating Method The electroless nickel plating method of the present invention includes the following steps (i) to (iii):
(I) a step of applying a catalyst for electroless plating to a printed wiring board;
(Ii) contacting the printed wiring board obtained in (i) with the catalyst residue remover of the present invention,
(Iii) including a step of performing electroless nickel plating on the printed wiring board obtained in (ii).

  Hereinafter, the electroless nickel plating method of the present invention will be specifically described.

(I) In the step (i) of applying the electroless plating catalyst, the electroless plating catalyst is applied to the printed wiring board.

  As a printed wiring board that is an object to be plated, for example, a resin such as epoxy resin or polyimide resin; glass; ceramics or the like as a base material, and a conductive pattern portion made of copper, silver, tungsten, molybdenum or the like is formed on the base material A substrate that has been used can be used.

  The method for applying the electroless plating catalyst is not particularly limited, and a catalyst for electroless plating such as palladium, silver, platinum, and ruthenium may be applied according to a known method. For example, when a palladium catalyst is provided, it is in contact with a catalyst solution for selective electroless plating that is a combination of a palladium compound and at least one compound selected from a specific halide, sulfate, hydrochloric acid, and sulfuric acid. Methods known in the art such as a catalyst-accelerator method, a sensitizer-activator method, and an alkali catalyst method can be employed. Among them, the method of contacting the selective electroless plating catalyst solution is preferable because only the conductive pattern portion of the printed wiring board can be selectively applied with a catalyst.

(Selective electroless plating catalyst solution)
The palladium compound used in the selective electroless plating catalyst solution is not particularly limited, and besides the water-soluble palladium compound, a palladium compound that can be made into an aqueous solution by dissolving in an acid or the like can also be used. Specific examples of palladium compounds suitable for use in the present invention include (NH ₄ ) ₂ [PdCl ₆ ], (NH ₄ ) ₂ [PdCl ₄ ], [PdCl ₂ (NH ₃ ) ₂ ], [PdI ₂ (NH _{3) 2], [Pd (} NO 2) 2 (NH 3) 2], K 2 [PdCl 6], K 2 [PdCl 4], K 2 [Pd (NO 2) 4], Na 2 [PdCl 4] , Na ₂ [Pd (NO ₂ ) ₄ ], PdBr ₂ , PdCl ₂ , PdI ₂ , Pd (NO ₃ ) ₂ .2H ₂ O, PdO, PdSO ₄ , PdS, [Pd (NH ₃ ) ₄ ] Cl ₂ , [Pd (NH ₃ ) ₄ ] (NO ₃ ) ₂ , Pd (C ₂ H ₃ O ₂ ) ₂ , Pd (NO ₃ ) ₂ , [Pd (NH ₃ ) ₄ ] (OH) ₂ . The addition amount of the palladium compound may be about 0.0001 to 0.5 mol / l, preferably about 0.0005 to 0.1 mol / l.

  The selective electroless plating catalyst solution is selected from alkali metal halides, alkali metal sulfates, alkaline earth metal halides, alkaline earth metal sulfates, ammonium halides, ammonium sulfate, hydrochloric acid and sulfuric acid. At least one compound is used in combination with a palladium compound.

  Examples of the alkali metal suitable for use in the catalyst solution for selective electroless plating include potassium and sodium, examples of the alkaline earth metal include calcium and magnesium, and examples of the halogen include chlorine, iodine and bromine. Can be illustrated. Preferred specific examples of the compound used in combination with the palladium compound include sodium chloride, potassium chloride, magnesium chloride, calcium chloride, ammonium chloride, potassium iodide, potassium bromide, potassium sulfate, sodium sulfate, ammonium sulfate, hydrochloric acid, sulfuric acid and the like. Can be illustrated. These compounds may be used alone or in appropriate combination, and the amount used may be about 0.1 to 10 mol / l, preferably 0.5 to 5 mol / l.

The pH of the selective electroless plating catalyst solution is not particularly limited, but when pH adjustment is performed, an acid such as HCl or H ₂ SO ₄ or an alkali compound such as NaOH is used as necessary. That's fine.

  A chelate compound can be added to the selective electroless plating catalyst solution as necessary, and the catalyst solution can be kept more stable. Specific examples of chelate compounds include ethylenediaminetetraacetic acid (EDTA), ethylenediaminetetraacetic acid disodium salt (EDTA · 2Na), hydroxyethylethylenediaminetriacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA), and triethylenetetraminehexaacetic acid (TTHA). ), Ethylenediaminetetrapropionic acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, nitrilotriacetic acid (NTA), iminodiacetic acid (IDA), iminodipropionic acid (IDP), aminotrimethylenephosphonic acid, aminotrimethylenephosphone Acid sodium salt, methylamine, ethylamine, propylamine, dimethylamine, trimethylamine, dimethylethylamine, benzylamine, 2-naphth Tylamine, isobutylamine, isoamylamine, methylenediamine, ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, diethylenetriamine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, cinnamylamine, p-methoxycinnami Ruamine, ammonia, 1-hydroxyethylidene-1, 1-diphosphonic acid, 1-hydroxyethylidene-1, 1-diphosphonic acid trisodium salt, citric acid, tartaric acid, malic acid, malonic acid, glycine, alanine, N-methylglycine , Glycosamine, dimethylglycine, hydantoic acid, aminovaleric acid, β-alanine, valine, norvaline, leucine, norleucine, isoleucine, serine, cysteine, aspa Gin, aspartic acid, glutamic acid, ornithine, lysine, arginine, glutamine, diaminopropionic acid, citrulline, hydroxy-L-lysine, diaminobutyric acid, aminoadipic acid, canalin, kynurenine, diaminopimelic acid, homocysteine, histidine, methionine, aspartyl- Histidine, alanyl-alanine, alanyl-β-alanine, β-alanyl-β-alanine, glycyl-lysine, alanyl-ornithine, lysyl-lysine, ornithyl-ornithine, glycyl-ornithine, β-alanyl-lysyl-lysine, ornithyl- Lysyl-lysine, glycyl-ornithyl-ornithine, imidazoline, 2,4,5-triphenyl-2-imidazoline, 2,2'-bis (2-imidazoline), pyridine, morpholine, bipyridy , Mention may be made of pyrazole, triazine and the like.

  In addition, a surfactant such as nonionic, cationic, anionic, and amphoteric can be added to the catalyst solution. Furthermore, thioureas can be added to promote substitution with palladium. Examples of thioureas include thiourea, dimethylthiourea, trimethylthiourea, allylthiourea, acetylthiourea, ethylenethiourea, and phenylthiourea. Further, as pH buffering agents, hydrochloric acid-potassium chloride, potassium hydrogen phthalate-hydrochloric acid, potassium hydrogen phthalate-sodium hydroxide, potassium dihydrogen phosphate-sodium hydroxide, boric acid-sodium hydroxide, sodium hydrogen carbonate-water Sodium oxide, disodium hydrogen phosphate-sodium hydroxide, sodium hydroxide-potassium chloride, tris (hydroxymethyl) aminomethane-hydrochloric acid, sodium acetate-acetic acid and the like can also be added. Surfactants, thioureas, and pH buffering agents can be used alone or in combination as needed. Chelate compounds, surfactants, thioureas and pH buffering agents are not essential components in the catalyst solution of the present invention, but in order to effectively exert the effect of addition, the addition amount of the chelate compound is: The addition amount of the surfactant is preferably about 0.01 to 10 g / l, and the addition amount of the thioureas is about 0.01 to 3 mol / l. The amount is preferably about mol / l, and the addition amount of the pH buffer is preferably about 0.01 to 1 mol / l.

  The treatment method with the catalyst solution of the present invention may be the same as the treatment with the ordinary catalyst solution, and the treatment object is placed in the catalyst solution at a liquid temperature of about 10 to 90 ° C., preferably about 25 to 70 ° C. What is necessary is just to immerse for about minutes.

  In addition, before giving the electroless-plating catalyst to the electroconductive pattern part of a printed wiring board, pre-processing, such as a degreasing process, pickling, and etching, can be performed with respect to a printed wiring board.

(Ii) In the step (ii) of contacting with the catalyst residue remover, the printed wiring board obtained in the step (i) is brought into contact with the catalyst residue remover of the present invention.

  The method for bringing the printed wiring board into contact with the catalyst residue remover is not particularly limited, and may be performed according to a known method. For example, by immersing the printed wiring board in the catalyst residue remover, it is possible to selectively remove only the electroless plating catalyst existing as a residue on the substrate, particularly efficiently. The treatment described above can be carried out with stirring or non-stirring of the catalyst residue remover.

  When the printed wiring board is immersed in and brought into contact with the catalyst residue remover, the temperature of the catalyst residue remover of the present invention is preferably about 20 ° C to 90 ° C, more preferably about 25 to 70 ° C. The treatment time is preferably about 10 seconds to 10 minutes, more preferably about 30 seconds to 5 minutes.

(Iii) In the step (iii) of performing electroless nickel plating, electroless nickel plating is performed on the printed wiring board obtained in (ii).

  The electroless nickel plating solution is not particularly limited, and a known electroless nickel plating solution comprising an aqueous solution containing a water-soluble nickel compound, a reducing agent, and a complexing agent can be used. For example, the electroless nickel-phosphorus alloy plating solution using hypophosphite as a reducing agent and the electroless nickel-boron alloy plating solution using boron compound as a reducing agent can be used. In addition, what is necessary is just to perform according to well-known conditions about the density | concentration, temperature, etc. of an electroless nickel plating solution.

  The thickness of the nickel plating film to be formed is usually about 1 to 10 μm. However, when the interval between the conductive pattern portions is narrow (for example, the interval is about 10 μm), the thickness is about 1 to 3 μm. preferable.

  In addition, a water washing process can be performed between each process of (i)-(iii).

  The catalyst residue remover of the present invention can selectively remove only the electroless plating catalyst present as a residue on the substrate of the printed wiring board. Therefore, it is possible to form an electroless nickel plating film excellent in fine pattern property on a printed wiring board.

Hereinafter, the present invention will be described in more detail with reference to examples.
Example As an object to be plated, 40 copper patterns (copper thickness 18 μm) having a line width of 10 μm, a slit width of 10 μm and a length of 3 cm on a 5 × 5 cm epoxy resin (thickness 1 mm) and a line width of 20 μm. A 40-thick copper pattern (copper thickness: 18 μm) having a slit width of 20 μm was used.

The object to be plated is degreased and then etched to about 0.5 μm with a sodium persulfate solution to give a catalyst-providing solution containing ICP Axela (Okuno Pharmaceutical Co., Ltd.) 200 ml. / L was used to apply the catalyst for 1 minute at room temperature, then immersed in each treatment solution (Example 1 to Example 9) described in Table 1 for 2 minutes, and then electroless nickel-phosphorus alloy plating (ICP Nicolon GM: manufactured by Okuno Pharmaceutical Co., Ltd.) was formed to 3 μm. In addition, the water washing between each process was performed for 1 minute with running water.
Comparative Example In the above embodiments, not immersed in the treatment liquid to be plated, washed with water and Comparative Example 1 The case of performing only compare the case of using a solution containing sodium hydrogen sulfate and sodium chloride as the processing liquid Example 2. The above Comparative Example 1 and Comparative Example 2 were also tested.

Fine pattern property evaluation method Each plated sample was examined for the presence or absence of plating spreading outside the copper pattern by microscopic observation (1000 times) of a wiring pattern portion having a line width of 10 μm or 20 μm. A case where there is no plating spread is indicated by ◎, a case where a slight plating spread is observed is indicated by a circle, and a case where many plating spreads are generated is indicated by a mark.

  In addition, the number of undeposited portions in the total of 80 wires was also evaluated.

  The evaluation results in Examples and Comparative Examples of the present invention are shown in Table 1 below.

  As is clear from the above results, when electroless nickel plating was performed using the catalyst residue remover of Examples 1 to 9 containing an alkylenediamine compound as an additive, the fine pattern property was particularly good. Of these, the fine pattern property was even better when used in combination with at least one compound selected from the group consisting of cyanide and thiocyanate. In addition, as for the precipitation property to the necessary part, the occurrence of non-precipitation was not recognized, and a good result was shown.

Claims (5)

The following general formula (I)

[Wherein R ¹ , R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom or the following group:

(Wherein R ⁵ is a linear or branched alkylene group having 1 to 5 carbon atoms, m is an integer of 1 to 10), and n is 2 or 3. ] The catalyst residue removal agent for printed wiring boards characterized by containing the alkylenediamine compound represented by these. ^2. The printed circuit board catalyst residue according to claim ¹ , wherein in the alkylenediamine compound represented by the general formula (I), at least one of the groups represented by R ¹ , R ² , R ³ and R ⁴ is a hydrogen atom. Remover. In alkylenediamine compound represented by the general formula ^{(I), R 1, R} 2, among the groups represented by ^{R 3} and ^{R 4,} according to claim 1 or 2 1-3 is a hydrogen atom Catalyst residue remover for printed wiring boards. Furthermore, the catalyst residue removal agent for printed wiring boards in any one of Claims 1-3 containing the at least 1 type of compound chosen from the group which consists of a cyanide compound and a thiocyanate. Electroless nickel plating method including the following steps (i) to (iii):
(I) a step of applying a catalyst for electroless plating to a printed wiring board;
(Ii) contacting the printed wiring board obtained in (i) with the catalyst residue remover according to any one of claims 1 to 4;
(Iii) A step of performing electroless nickel plating on the printed wiring board obtained in (ii).