Catalyst-imparting liquid for electroless plating, catalyst-imparting method, and electroless plating method

Abstract

The present invention provides a catalyst-imparting solution for forming an electrolysis-free plating film on a metal material, which is excellent in plating deposition and patterning. Specifically, the present invention provides an electrolysis-free plating catalyst-imparting solution, which contains: (A) at least one cationic compound selected from a cationic polymer and a cationic surfactant, and (B) a metal catalyst, wherein the metal catalyst (B) contains at least one selected from Pd, Au, Ag, and Pt, the pH of the electrolysis-free plating catalyst-imparting solution is 5 or less, the content of the cationic compound (A) is 0.01 mg / L to 1000 mg / L, and the content of the metal catalyst (B) is 0.01 mg / L to 100 mg / L.

Description

Technical Field

[0001] This invention relates to a catalyst-adding solution for electroless plating, a catalyst-adding method, and an electroless plating method. Background Technology

[0002] In electronic-related fields such as printed circuit boards, semiconductor packaging, and electronic components, one of the final processes in manufacturing is electroless plating of conductor circuits, terminal parts, etc. Moreover, when electroless plating is performed on the metal material of the substrate, a catalyst-giving treatment is sometimes performed to improve the plating precipitation, etc., in which a metal catalyst such as palladium, which serves as the catalyst core, is precipitated on the metal material through a displacement reaction (for example, see Patent Document 1).

[0003] Electroless plating processes on metallic materials such as copper circuits typically require immersing the material in a catalyst-feeding solution containing 10–100 mg / L palladium. However, in recent years, the high price of metal catalysts, particularly palladium, has necessitated a reduction in the concentration of the metal catalyst in the catalyst-feeding solution.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2011-058062 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] The inventors of this invention discovered that when the palladium concentration is reduced, insufficient catalyst nuclei are formed on the copper circuit, so it cannot function fully as a catalyst for electroless plating deposition, resulting in low plating deposition performance.

[0009] Furthermore, the inventors of this invention have discovered that while extending the immersion time in the palladium catalyst-giving solution to improve plating precipitation can adsorb sufficient palladium catalyst onto the copper circuit, the palladium catalyst is also easily adsorbed onto the surface of the insulator, resulting in a problem of difficulty in obtaining sufficient patterning due to the expansion of plating.

[0010] Thus, when using existing catalyst-feeding solutions, the deposition and patterning of the plating on the invented metal material are insufficient when the concentration of the metal catalyst in the catalyst-feeding solution is low.

[0011] The present invention is made in view of the current state of the prior art, and its main purpose is to provide a catalyst feeding solution for forming an electroless plating film with excellent deposition and patterning properties on metal materials.

[0012] Technical solutions for solving technical problems

[0013] The inventors of this invention conducted repeated and in-depth research to achieve the aforementioned objectives. As a result, they discovered that by using a catalyst-providing solution for electroless plating containing (A) at least one cationic compound selected from cationic polymers and cationic surfactants, and (B) a metal catalyst, an electroless plating film with excellent plating deposition and patterning on metallic materials can be formed. Based on this discovery, the inventors of this invention conducted further repeated research, thereby completing this invention. That is, this invention includes the following embodiments.

[0014] Item 1. A catalyst-adding solution for electroless plating, comprising:

[0015] (A) at least one cationic compound selected from cationic polymers and cationic surfactants, and

[0016] (B) Metal catalyst,

[0017] The aforementioned (B) metal catalyst comprises at least one selected from Pd, Au, Ag, and Pt.

[0018] The catalyst-converting solution used in this electroless plating process has a pH below 5.

[0019] The content of the above-mentioned cationic compound (A) is 0.01 mg / L to 1000 mg / L.

[0020] The content of the metal catalyst (B) mentioned above is 0.01 mg / L to 100 mg / L.

[0021] Item 2. The catalyst-giving liquid as described in Item 1, wherein the cationic compound (A) comprises at least one selected from polyethyleneimine, diallyl dimethyl ammonium chloride sulfur dioxide copolymer, methyl diallylamine hydrochloride polymer, diallyl dimethyl ammonium chloride polymer, dicyandiamide-polyalkylene polyamine condensate, dicyandiamide-type cationic resin, allylamine hydrochloride-diallylamine hydrochloride polymer, allylamine hydrochloride polymer, allylamine polymer, O-[2-hydroxy-3-(trimethylammonium)propyl]hydroxyethyl cellulose chloride, polylysine, cationic guar gum, cocoamine acetate, tetradecylamine acetate, octadecylamine acetate, dialcyl dimethyl ammonium chloride, cocoalkyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium chloride, and stearyl trimethyl ammonium chloride.

[0022] Item 3. The catalyst-giving liquid as described in Item 1 or 2, wherein the metal catalyst described above (B) comprises Pd.

[0023] Item 4. The catalyst-giving liquid as described in any one of items 1 to 3, further comprising (C) at least one acid selected from organic acids and inorganic acids.

[0024] Item 5. The catalyst-giving liquid as described in Item 4, wherein the acid (C) comprises at least one selected from acetic acid, malonic acid, succinic acid, adipic acid, maleic acid, fumaric acid, glycolic acid, lactic acid, malic acid, gluconic acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, methanesulfonic acid, glutamic acid, aspartic acid, and boric acid.

[0025] Item 6. The catalyst-giving liquid as described in any one of items 1 to 5 further contains (D) chloride.

[0026] Item 7. The catalyst-giving liquid as described in Item 6, wherein the (D) chloride comprises at least one selected from potassium chloride, sodium chloride, ammonium chloride, calcium chloride, magnesium chloride, lithium chloride, trichloroacetaldehyde, and chlorine dioxide.

[0027] Item 8. The catalyst-giving liquid as described in Item 6 or 7, wherein the content of the above-mentioned (D) chloride is 0.01 to 200 g / L.

[0028] Item 9. The catalyst-giving liquid as described in any one of Items 1 to 8, wherein the electroless plating is selected from at least one of electroless palladium plating, electroless palladium alloy plating, electroless nickel plating, electroless nickel alloy plating, electroless silver plating, electroless silver alloy plating, electroless gold plating, and electroless gold alloy plating.

[0029] Item 10. The catalyst-giving liquid as described in any one of items 1 to 9, wherein the electroless plating is plating a substrate having insulating and conductive regions on its surface.

[0030] Item 11. A method for imparting a catalyst for electroless plating, comprising: (1) a step of bringing the catalyst imparting liquid of any one of items 1 to 10 into contact with the object to be plated.

[0031] Item 12. An electroless plating method, comprising in sequence: (1) a step of contacting the catalyst-gathering solution as described in any one of items 1 to 10 with the object to be plated; and

[0032] (2) The process of electroless plating.

[0033] Item 13. A substrate for a catalyst imparted by the catalyst imparting method described in Item 11.

[0034] Item 14. A substrate that has undergone electroless plating treatment by the electroless plating method described in Item 12.

[0035] The effects of the invention

[0036] The catalyst-giving solution for electroless plating of the present invention is useful for forming electroless plating films with excellent plating precipitation and patterning on metallic materials. Detailed Implementation

[0037] In this specification, the expressions “containing” and “including” include any one of the following meanings: “containing”, “including”, “containing only”, “substantially consisting only of” and “consisting only of”.

[0038] In this specification, the numerical range of "A to B" means "above A and below B".

[0039] 1. Catalyst-donating liquid

[0040] The catalyst-attributing solution for electroless plating of the present invention (hereinafter, in this specification, it is sometimes referred to as "the catalyst-attributing solution of the present invention" or "catalyst-attributing solution") contains (A) at least one cationic compound selected from cationic polymers and cationic surfactants (hereinafter, sometimes simply referred to as "(A) cationic compound") and (B) a metal catalyst. The catalyst-attributing solution of the present invention, having the above-described structure, contains at least one cationic compound selected from cationic polymers and cationic surfactants in addition to (B) the metal catalyst, enabling sufficient catalyst attribution to the surface of the object to be plated. Therefore, it exhibits excellent plating deposition properties, suppresses the adsorption of palladium catalyst on the insulator surface, thus suppressing plating expansion, exhibiting sufficient patterning, and suppressing corrosion of copper surfaces. The present invention will now be described in detail.

[0041] (A) Cationic compounds

[0042] (A) Cationic compounds are not particularly limited as long as they can be adsorbed onto the insulating part through electrostatic interaction. Examples of cationic compounds (A) include: polyethyleneimine, diallyl dimethyl ammonium chloride sulfur dioxide copolymer, methyl diallylamine hydrochloride polymer, diallyl dimethyl ammonium chloride polymer, dicyandiamide-polyalkylene polyamine condensate, dicyandiamide-type cationic resin, allylamine hydrochloride-diallylamine hydrochloride polymer, allylamine hydrochloride polymer, allylamine polymer, O-[2-hydroxy-3-(trimethylammonium)propyl]hydroxyethyl cellulose, polylysine, cationic guar gum, cocoamine acetate, tetradecylamine acetate, octadecylamine acetate, dialcyl dimethyl ammonium chloride, cocoalkyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, etc. Among these, from the viewpoint of forming an electroless plating film with superior plating precipitation and patterning on metallic materials, cationic polymers are preferred, and diallyl dimethyl ammonium chloride sulfur dioxide copolymer, methyl diallylamine hydrochloride polymer, diallyl dimethyl ammonium chloride polymer, allylamine hydrochloride-diallylamine hydrochloride polymer, allylamine hydrochloride polymer, and allylamine polymer are more preferred.

[0043] As specific examples of (A) cationic compounds, compounds such as those shown in the following general formula can be listed.

[0044]

[0045] [In the formula, n represents an integer from 10 to 1500, l represents an integer greater than 1, and m represents an integer greater than 2. The upper limits of the numerical ranges of l and m are not particularly limited, as long as they do not contradict the preferred weight-average molecular weight range of the cationic polymer described later. Additionally, R represents an alkyl group with 8 to 18 carbon atoms.]

[0046] (A) The molecular weight of the cationic compound is not particularly limited. In the case that (A) the cationic compound is a cationic polymer, the weight-average molecular weight is preferably 1,000 to 1,000,000.

[0047] (A) Cationic compounds may be used alone or in combination of two or more.

[0048] The content of the cationic compound (A) in the catalyst-giving solution of the present invention is 0.01 mg / L to 1000 mg / L. By keeping the content of the cationic compound (A) within the above range, the catalyst-giving solution of the present invention can suppress foaming of the plating solution and reduce manufacturing costs. From the viewpoint of forming an electroless plating film with better plating precipitation and patterning on the metal material, the content of the cationic compound (A) is preferably 0.05 mg / L to 1000 mg / L, more preferably 0.1 mg / L to 1000 mg / L, and even more preferably 1 mg / L to 1000 mg / L.

[0049] (B) Metal catalysts

[0050] (B) The metal contained in the metal catalyst includes at least one metal selected from Pd, Au, Ag, and Pt. Among these, Pd is preferred from the viewpoint of forming an electroless plating film with superior deposition properties and patterning on the metal material.

[0051] (B) Metal catalysts can be used alone or in combination of two or more.

[0052] The content of the (B) metal catalyst in the catalyst-giving solution of the present invention is 0.01 mg / L to 100 mg / L. From the viewpoint of forming an electroless plating film with superior deposition and patterning properties on the metal material, the content of the (B) metal catalyst is preferably 0.05 mg / L to 100 mg / L, more preferably 0.1 mg / L to 100 mg / L. Using the catalyst-giving solution of the present invention, even with a small amount of metal catalyst (e.g., a content of 20 mg / L or less in the catalyst-giving solution), an electroless plating film with superior deposition and patterning properties on the metal material can be formed, thus reducing the formation cost of the electroless plating film.

[0053] From the viewpoint of forming an electroless plating film with superior plating precipitation and patterning on a metal material, the content of (B) metal catalyst in the catalyst-giving liquid of the present invention is preferably 0.001 to 100 parts by mass relative to 1 part by mass of (A) cationic compound, more preferably 0.005 to 50 parts by mass, and even more preferably 0.01 to 10 parts by mass.

[0054] In the catalyst-feeding solution of the present invention, the (B) metal catalyst is preferably present in an ionic state. Furthermore, the (B) metal catalyst preferably does not form a colloid. In this case, the adsorption of the (B) metal catalyst on the insulating regions of the substrate is suppressed, and the (B) metal catalyst is readily and efficiently deposited on the conductive regions of the substrate through a displacement reaction. Therefore, an electroless plating film with superior plating deposition and patterning on the metal material can be formed.

[0055] (C) acid

[0056] The catalyst-giving solution of the present invention is preferably acidic. By making the catalyst-giving solution of the present invention acidic, the cationic nature of (A) the cationic compound can be utilized more effectively. Specifically, the adsorption (deposition) of (B) the metal catalyst on the insulating material can be suppressed, thus facilitating the formation of an electroless plating film with excellent deposition and patterning on the metal material. In this specification, acidic means pH less than 7, and preferably pH less than 6.9 or 6.8.

[0057] The pH of the catalyst-giving solution of the present invention is 5 or less. From the viewpoint of forming an electroless plating film with excellent plating deposition and patterning on a metallic material, the pH is preferably 3 or less, and more preferably 1 or less. By setting the pH of the catalyst-giving solution of the present invention to 5 or less, the cationic nature of (A) the cationic compound can be effectively utilized. Specifically, the adsorption of (B) the metal catalyst on the insulator can be suppressed, thus being useful for forming an electroless plating film with excellent plating deposition and patterning on a metallic material.

[0058] From the viewpoint that the catalyst-giving liquid of the present invention is acidic as described above, the catalyst-giving liquid of the present invention may contain, in addition to (A) a cationic compound and (B) a metal catalyst, (C) at least one acid selected from organic and inorganic acids (hereinafter simply referred to as "(C) acid"). By containing (C) acid in the catalyst-giving liquid of the present invention, the cationic nature of (A) cationic compound can be effectively utilized. Specifically, the adsorption of (B) metal catalyst on insulating regions can be suppressed, thus facilitating the formation of an electroless plating film with excellent deposition and patterning on the metal material.

[0059] (C) The acid is not particularly limited as long as it is soluble in the catalyst-giving solution. Specifically, examples of (C) acids include acetic acid, malonic acid, succinic acid, adipic acid, maleic acid, fumaric acid, glycolic acid, lactic acid, malic acid, gluconic acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, methanesulfonic acid, glutamic acid, aspartic acid, and boric acid. Among these, glycolic acid, sulfuric acid, hydrochloric acid, and methanesulfonic acid are preferred from the viewpoint of forming an electroless plating film with excellent deposition and patterning properties on metallic materials.

[0060] (C) One acid may be used alone or in combination of two or more.

[0061] In the case of (C) acid, its content is only required as long as the pH is within the above range, and there is no particular limitation.

[0062] (D) Chloride

[0063] In addition to the compounds described above, the catalyst-feeding solution of the present invention may also contain (D) chloride. Typically, when a metal material is immersed in a catalyst-feeding solution for an extended period, corrosion caused by the metal catalyst occurs. However, when the catalyst-feeding solution of the present invention contains (D) chloride, it is possible to further suppress corrosion of the metal material during the processing steps while simultaneously forming an electroless plating film on the metal material with excellent deposition characteristics and patterning. Furthermore, when using a catalyst-feeding solution containing (D) chloride, the patterning of the electroless plating film on the metal material can be further improved compared to the case where (D) chloride is not used.

[0064] (D) There are no particular limitations as long as the chloride is soluble in the catalyst-giving solution. Examples of (D) chlorides include potassium chloride, sodium chloride, ammonium chloride, calcium chloride, magnesium chloride, lithium chloride, trichloroacetaldehyde, and chlorine dioxide. Among these, sodium chloride, potassium chloride, and ammonium chloride are preferred from the viewpoint of forming an electroless plating film with excellent deposition and patterning properties on metallic materials.

[0065] (D) Chlorides can be used alone or in combination of two or more.

[0066] When the catalyst-giving liquid of the present invention contains (D) chloride, its content is not particularly limited, but is preferably 0.01 g / L to 200 g / L, more preferably 1 g / L to 100 g / L, and even more preferably 3 g / L to 50 g / L. Excessive chloride makes the metal material itself more soluble, which can promote corrosion or lead to chloride formation on the metal material, thus hindering the displacement reaction of the metal catalyst. Conversely, insufficient chloride makes it difficult to adequately suppress corrosion of the metal material due to insufficient chloride ions in the catalyst-giving liquid.

[0067] The catalyst-giving liquid of the present invention preferably contains water as the main solvent. The catalyst-giving liquid of the present invention may also contain solvents other than water. As for the solvents other than water that may be included in the catalyst-giving liquid of the present invention, there are no particular limitations as long as they do not impair the effects of the present invention. Examples include: alcohols such as methanol, ethanol, isopropanol, isobutanol, sec-butanol, tert-butanol, ethylene glycol, and glycerol; ethers such as ethylene glycol dimethyl ether, 1,4-dioxane, and tetrahydrofuran; and ketones such as acetone and methyl ethyl ketone. When solvents other than water are also included, their content is not particularly limited, but is preferably 5% by mass or less, more preferably 0.5% by mass or less, relative to 100% by mass of the solvent. By setting the upper limit of the content of solvents other than water to the above range, the reduction in the effect of cationic compounds caused by the hydrophobicity of the solvent can be further suppressed.

[0068] Various additives can also be added to the catalyst-giving liquid of the present invention as needed. Examples of additives include stabilizers, pH buffers, and surfactants.

[0069] As a stabilizer, one or more of the following can be added individually or in combination: lead salts such as lead nitrate and lead acetate; bismuth salts such as bismuth nitrate and bismuth acetate; and sulfur compounds such as sodium thiosulfate. When a stabilizer is added, there is no particular limitation on the amount added, which can be set to, for example, approximately 0.01 mg / L to approximately 100 mg / L.

[0070] As pH buffers, sodium, potassium, and ammonium salts of substances such as acetic acid, boric acid, phosphoric acid, phosphorous acid, carbonic acid, phthalic acid, and oxalic acid can be added individually or in combination of two or more. When adding a pH buffer, there is no particular limitation on the amount added; from the viewpoint of bath stability, it can be set to approximately 0.002 mol / L to approximately 1 mol / L.

[0071] In addition to the cationic surfactants mentioned above, various surfactants such as nonionic, anionic, and amphoteric surfactants can also be used as surfactants. Examples include alkali metal salts of aromatic or aliphatic sulfonic acids and alkali metal salts of aromatic or aliphatic carboxylic acids. Surfactants can be used alone or in combination of two or more. When adding surfactants, there is no particular limitation on the amount added, which can be set to, for example, approximately 0.01 mg / L to approximately 1000 mg / L.

[0072] The catalyst-giving solution of the present invention preferably does not contain a reducing agent. In this case, by suppressing the colloidal formation of the (B) metal catalyst, the adsorption of the (B) metal catalyst on the insulating region of the substrate can be suppressed, and the (B) metal catalyst can be easily and efficiently deposited on the conductive region of the substrate through a displacement reaction. Therefore, an electroless plating film with better plating deposition and patterning on the metal material can be formed.

[0073] 2. Catalyst preparation methods

[0074] In one aspect, the present invention relates to a method for manufacturing an electroless plating material containing a catalyst core, comprising (1) a step of contacting the catalyst-giving liquid of the present invention with the plating material, or a method for performing a catalyst-giving treatment on an electroless plating material (in this specification, it is sometimes referred to as "method 1 of the present invention"). This will be described below.

[0075] The material to be plated can be any material with metal exposed on its surface; there are no particular limitations. For example, as raw materials, it can be one or a combination of materials such as glass fiber reinforced epoxy resin, polyimide, PET and other plastics, glass, ceramics, metal oxides, metals, paper, synthetic or natural fibers, etc. As for its shape, it can be any shape such as sheet, film, cloth, fiber, tube, etc.

[0076] Examples of materials to be plated include printed circuit boards, semiconductor packages, electronic components, and ceramic substrates. In these materials, the exposed metal on the surface can form wiring.

[0077] Examples of metals exposed on the surface include copper, copper alloys, nickel, nickel alloys, silver, silver alloys, gold, gold alloys, platinum, platinum alloys, molybdenum, and tungsten. Among these, copper alloys, silver alloys, gold alloys, and platinum alloys are suitable for alloys containing, for example, 50% or more by mass of copper, nickel, silver, gold, or platinum.

[0078] As described above, the object to be plated is preferably an object having insulating and conductive regions on its surface. In this case, by method 1 of the present invention, (A) a cationic compound is pre-adsorbed onto the insulating region, and part or all of the (B) metal catalyst used is efficiently deposited onto the conductive region through a displacement reaction. That is, by method 1 of the present invention, catalyst nuclei containing the (B) metal catalyst can be efficiently formed on the conductive region (particularly the surface metal) of the object to be plated. Therefore, according to method 1 of the present invention, in the subsequent electroless plating process, both the plating deposition on the metal material can be ensured, and an electroless plating film with excellent patterning can be easily formed.

[0079] By method 1 of the present invention, a catalyst-equipped material can be obtained, specifically, a substrate having insulating and conductive regions on its surface, a metal catalyst 1 having the conductive regions, and a material (substrate) that inhibits the adhesion of the metal catalyst 1 to the insulating regions. By performing an electroless plating process on the substrate, which is such a catalyst-equipped material, an electroless plating film with superior plating precipitation and patterning (selective precipitation) can be formed. The catalyst core containing the metal catalyst is for surface activation, therefore its thickness is set, for example, to be 0.05 μm or less, or 0.005 μm to 0.05 μm.

[0080] The substrate to be plated preferably underwent pretreatment such as degreasing and soft etching.

[0081] There are no particular limitations on the specific method for contacting the catalyst-adding solution of the present invention with the object to be plated; generally, it is sufficient to immerse the object to be plated in the catalyst-adding solution of the present invention. Alternatively, catalyst-adding treatment can be performed by coating or spraying the catalyst-adding solution onto the surface of the object to be plated.

[0082] When the catalyst-giving liquid of the present invention is prepared by impregnation, the liquid temperature of the catalyst-giving liquid of the present invention is generally preferably about 10°C to 90°C, more preferably about 20°C to 40°C, and even more preferably 25°C to 35°C.

[0083] Regarding the processing time, it is preferably about 10 seconds to 20 minutes, more preferably about 30 seconds to 5 minutes, and even more preferably 1 minute to 3 minutes.

[0084] 3. Electroless plating method

[0085] In one embodiment, the present invention relates to a method for manufacturing a material comprising an electroless plating film, or a method for electroless plating of a substrate (sometimes referred to as "method 2 of the present invention") comprising (1) a step of contacting the catalyst-giving liquid of the present invention with the substrate, and (2) a step of performing an electroless plating treatment. This will be described below.

[0086] Regarding process (1), as described in “2. Catalyst Implantation Method” above.

[0087] (2) Electroless plating process can be carried out by contacting the catalyst-containing material (the object to be plated) obtained in process (1) with the electroless plating solution.

[0088] Prior to electroless plating, some or all of the (A) cationic compounds on the substrate can be removed. The removal of (A) cationic compounds can be carried out by a conventional water washing process.

[0089] There are no particular limitations on the electroless plating solution; self-catalyzing electroless plating solutions can be used. Examples include electroless palladium plating solutions, electroless palladium alloy plating solutions, electroless copper plating solutions, electroless copper alloy plating solutions, electroless nickel plating solutions, electroless nickel alloy plating solutions, electroless silver plating solutions, electroless silver alloy plating solutions, electroless gold plating solutions, and electroless gold alloy plating solutions. Regarding the specific composition of these electroless plating solutions, there are no particular limitations; self-catalyzing electroless plating solutions with known compositions containing reducing agents can be used. As for plating conditions, standard plating conditions can be followed depending on the type of plating solution used.

[0090] In step (2) of method 2 of the present invention, preferred electroless plating solutions include: electroless palladium plating solution, electroless palladium alloy plating solution, electroless nickel plating solution, electroless nickel alloy plating solution, electroless silver plating solution, electroless silver alloy plating solution, electroless gold plating solution, and electroless gold alloy plating solution. When using an electroless nickel plating solution or an electroless nickel alloy plating solution in step (2), it is preferable to further perform electroless silver plating, electroless silver alloy plating, electroless gold plating, or electroless gold alloy plating. Furthermore, when using an electroless nickel plating solution or an electroless nickel alloy plating solution in step (2), it is preferable to further perform electroless palladium plating or electroless palladium alloy plating, and more preferably, to continue with electroless gold plating or electroless gold alloy plating thereafter. Additionally, when using an electroless palladium plating solution or an electroless palladium alloy plating solution in step (2), it is preferable to further perform electroless gold plating or electroless gold alloy plating. Alternatively, in process (2), only electroless palladium plating solution, electroless palladium alloy plating solution, electroless nickel plating solution, electroless nickel alloy plating solution, electroless silver plating solution, electroless silver alloy plating solution, electroless gold plating solution, or electroless gold alloy plating solution may be used.

[0091] By method 2 of the present invention, an electroless plating film with superior plating precipitation and patterning (selective precipitation) can be formed. By method 2 of the present invention, a material that provides such an electroless plating film can be obtained, specifically, a material (substrate) having a substrate having insulating and conductive regions on its surface, a metal catalyst 1 on the conductive regions, and a film 2 on the metal catalyst 1, and suppressing the formation of the metal catalyst 1 and / or the film 2 on the insulating regions.

[0092] Example

[0093] The following examples and comparative examples illustrate the present invention in more detail. However, the present invention is not limited to the examples.

[0094] (Preparation of catalyst-donating liquid)

[0095] The raw materials shown in Table 1 were added sequentially to water as a solvent in the proportions shown in Table 1 to prepare 500 mL of catalyst-giving solution for each example and comparative example.

[0096] (Evaluation Test)

[0097] In the following evaluation tests, after pretreatment (acidic degreasing, soft etching) of the substrate, catalyst nuclei were formed on the metal surface using the prepared catalyst-feeding solution. Then, electroless nickel plating or electroless palladium plating was performed, followed by electroless gold plating. Details of each treatment are described below unless otherwise specified. A 1-minute running water rinse was performed between each process.

[0098] (a) Acid degreasing

[0099] Immerse for 5 minutes at 40°C in an acidic degreasing solution (trade name: ICP Clean S-135K) containing sulfuric acid and surfactants.

[0100] (b) Soft etching

[0101] Immerse for 1 minute at room temperature in an aqueous solution containing 100 g / L sodium persulfate and 10 mL / L 98% sulfuric acid.

[0102] (c) Catalyst-prepared treatment

[0103] The catalysts were immersed in the catalyst-feeding solutions under the conditions shown in Table 1. Specifically, the pH was below 1 in Examples 1-41 and Comparative Examples 1-5, and 6.8 in Examples 42-48 and Comparative Example 6. The immersion time was 1 minute in Examples 1-34 and Comparative Examples 1-4, and 3 minutes in Examples 35-48 and Comparative Examples 5 and 6. The processing temperature was 30°C in all catalyst-feeding solutions.

[0104] (d-1) Electroless nickel plating

[0105] A 4 μm thick coated film was obtained by immersing the nickel in an electroless nickel plating solution (trade name: ICP NICORON FPF, manufactured by Okuno Pharmaceutical Co., Ltd.) at 84°C for 25 minutes.

[0106] (d-2) Electroless palladium plating

[0107] A coating film with a thickness of 0.1 μm was obtained by immersing the product in an electroless palladium plating solution (trade name: TOP PALLAS PD, manufactured by Okuno Pharmaceutical Co., Ltd.) at 65°C for 5 minutes.

[0108] (e) Electroless gold plating

[0109] A plating film with a thickness of 0.05 μm was obtained by immersing the sample in an electroless gold plating solution (trade name: TOP PALLAS AU, manufactured by Okuno Pharmaceutical Co., Ltd.) at 80°C for 1 minute.

[0110] Experimental Example 1: Evaluation of Plating Precipitation

[0111] As the substrate to be plated, a resin substrate is prepared with micro-copper pads that are corrosion-resistant. A BGA resin substrate (30 pads) was used. Electroless plating was performed on the BGA resin substrate using the above-described processing steps. The deposition state of the electroless plating on the micropads was observed under a microscope (300x magnification). Evaluation was performed according to the following criteria.

[0112] 〇: No unprecipitated material at all

[0113] △: Only slightly confirmed that no precipitation occurred.

[0114] ×: A large amount of unprecipitated material was produced.

[0115] Experimental Example 2: Evaluation of Pattern

[0116] As the substrate to be plated, a BGA resin substrate with fine wiring (L / S = 50 / 50 μm) on a resin base was prepared. Electroless plating was performed on the BGA resin substrate using the processing steps described above. For the wiring pattern area with L / S = 50 / 50 μm after electroless plating, the presence or absence of enlargement of the electroless plating was observed under a microscope (1000x). Evaluation was conducted according to the following evaluation criteria.

[0117] 〇: No plating enlargement at all

[0118] △: Only slight confirmation of plating expansion

[0119] ×: This results in a significant increase in plating coverage.

[0120] The results are shown in Tables 1-7.

[0121] [Table 1]

[0122]

[0123] [Table 2]

[0124]

[0125] [Table 3]

[0126]

[0127] [Table 4]

[0128]

[0129] [Table 5]

[0130]

[0131] [Table 6]

[0132]

[0133] [Table 7]

[0134]

Claims

1. A catalyst-feeding solution for electroless plating, characterized in that, contain: (A) At least one cationic compound selected from cationic polymers and cationic surfactants, and (B) Metal catalyst, The (B) metal catalyst comprises at least one selected from Pd, Au, Ag, and Pt. The pH of the catalyst-feeding solution used in the electroless plating is below 1. The content of the cationic compound (A) is 0.01 mg / L to 1000 mg / L. The content of the metal catalyst (B) is 0.01 mg / L to 100 mg / L.

2. The catalyst-feeding liquid as described in claim 1, characterized in that: The (A) cationic compound comprises at least one selected from polyethyleneimine, diallyl dimethyl ammonium chloride sulfur dioxide copolymer, methyl diallylamine hydrochloride polymer, diallyl dimethyl ammonium chloride polymer, dicyandiamide-polyalkylene polyamine condensate, dicyandiamide-type cationic resin, allylamine hydrochloride-diallylamine hydrochloride polymer, allylamine hydrochloride polymer, allylamine polymer, O-[2-hydroxy-3-(trimethylammonium)propyl]hydroxyethyl cellulose, polylysine, cationic guar gum, cocoamine acetate, tetradecylamine acetate, octadecylamine acetate, decyl dimethyl ammonium chloride, cocoalkyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium chloride, and stearyl trimethyl ammonium chloride.

3. The catalyst-feeding liquid as described in claim 1, characterized in that: The (B) metal catalyst contains Pd.

4. The catalyst-feeding liquid as described in claim 1, characterized in that: It also contains (C) at least one acid selected from organic and inorganic acids.

5. The catalyst-feeding liquid as described in claim 4, characterized in that: The acid (C) comprises at least one selected from acetic acid, malonic acid, succinic acid, adipic acid, maleic acid, fumaric acid, glycolic acid, lactic acid, malic acid, gluconic acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, methanesulfonic acid, glutamic acid, aspartic acid, and boric acid.

6. The catalyst-feeding liquid according to claim 1, characterized in that: It also contains (D) chloride.

7. The catalyst-feeding liquid as described in claim 6, characterized in that: The (D) chloride comprises at least one selected from potassium chloride, sodium chloride, ammonium chloride, calcium chloride, magnesium chloride, lithium chloride, trichloroacetaldehyde, and chlorine dioxide.

8. The catalyst-feeding liquid as described in claim 6, characterized in that: The content of (D) chloride is 0.01 g / L to 200 g / L.

9. The catalyst-feeding liquid according to claim 1, characterized in that: The electroless plating is selected from at least one of the following: electroless palladium plating, electroless palladium alloy plating, electroless nickel plating, electroless nickel alloy plating, electroless silver plating, electroless silver alloy plating, electroless gold plating, and electroless gold alloy plating.

10. The catalyst-feeding liquid according to claim 1, characterized in that: The electroless plating is a plating process applied to a substrate with insulating and conductive areas on its surface.

11. A method for imparting a catalyst for electroless plating, characterized in that, include: (1) A process of bringing the catalyst-giving liquid of any one of claims 1 to 10 into contact with the object to be coated.

12. An electroless plating method, characterized in that, In order, they include: (1) A process of bringing the catalyst-gathering liquid of any one of claims 1 to 10 into contact with the object to be coated; and (2) The process of electroless plating.

13. A substrate for which a catalyst has been imparted by the catalyst imparting method of claim 11.

14. A substrate that has undergone electroless plating treatment by the electroless plating method of claim 12.

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