KR100367164B1 - Metal plating pretreatment agent and metal plating method using the same - Google Patents

Abstract

The present invention provides an electroless plating method that can be easily applied to powders or mirrored objects, and also provides a metal plating pretreatment agent for the method. This pretreatment agent contains the silane coupling agent obtained by reaction of the azole type compound which has an active functional group which forms a complex with a noble metal ion, and an epoxy silane type compound. The plated material subjected to the surface treatment using this is treated with a solution containing noble metal ions, followed by electroless plating to perform metal plating.

Description

Metal Plating Pretreatment and Metal Plating Method Using Them {METAL PLATING PRETREATMENT AGENT AND METAL PLATING METHOD USING THE SAME}

The electroless metal plating method is one of methods for forming a metal film on a substrate having no conductivity, and as a pretreatment for electroless plating, a method called activation in which a noble metal such as palladium is previously attached to the substrate as a catalyst is used. So far, SnCl after treatment with hydrochloric acid sex aqueous solution of ₂ to adsorb Pd by treatment with immersion in PdC1 ₂ solution on a substrate, or has a method of supporting Pd on the surface by the colloidal solution containing Sn and Pd are used. These methods have many problems, such as a complicated process from the point of view of using Sn. Therefore, in recent years, various methods have been proposed using a silane coupling agent having a functional group capable of forming a complex with these precious metals as a method of supporting a surface of a precious metal such as Pd, which is used as a catalyst for electroless plating. Japanese Patent Application Laid-Open No. 59-52701, Japanese Patent Application Laid-Open No. 60-181294, Japanese Patent Application Laid-Open No. 61-194183, and Japanese Patent Application Laid-Open No. 3-44149. However, if the silane coupling agent shown therein is to be uniformly adsorbed on a substrate, the conventional aminosilane coupling agent and the epoxy silane coupling agent are easily gelled by the dehydrogenation condensation reaction in an aqueous solution and cannot be dissolved at high concentration. In addition, hydrolytic condensation hardly occurs in the organic solvent, and since most of them exist as monomers, the viscosity of the liquid is low. For this reason, even if such a silane coupling agent is apply | coated uniformly on a mirror object, since adjustment of the thickness of a film is difficult, the coupling agent could only provide a thin film. For this reason, since only a small amount of the functional group trapping the noble metal can exist on the surface, the noble metal having the function of the plating catalyst in the subsequent step may be unevenly attached. As a result, it was difficult to form an electroless plated film uniformly. For this reason, the method of roughening the surface by hydrofluoric acid and the strong alkaline liquid which made the surface electroless plating to the mirror glass surface is still performed now. In addition, even in the treatment to the powder, since the conventional aminosilane coupling agent and the epoxy silane coupling agent have little adhesion to the surface, the solvent of the treatment liquid is completely volatilized and the coupling agent is forcibly adhered to the powder surface, followed by heating. It had to be dried and hydrolyzed and condensed.

[Initiation of invention]

The present invention provides a method for metal plating by a new electroless plating capable of successfully electroless plating even on powders or mirrors which have been difficult to apply electroless plating in a conventional manner in this respect, and a metal plating pretreatment agent therefor. The purpose is to.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining, the present inventors discovered that the problem mentioned above can be solved by selecting a specific silane coupling agent as a silane coupling agent which has a complex formation function with the said noble metal ion, and came to this invention.

That is, the present invention,

(1) a metal plating pretreatment agent comprising a silane coupling agent obtained by a reaction between an azole compound having an active functional group forming a complex with a noble metal ion and an epoxy silane compound,

(2) After treating the plated material surface-treated with a silane coupling agent obtained by the reaction of an azole compound having an active functional group forming a complex with a noble metal ion and an epoxysilane-based compound with a solution containing a noble metal ion, Metal plating method characterized by electroless plating,

(3) The metal plating method according to the above (2), wherein the azole compound is imidazole;

(4) The metal plating method according to the above (2), wherein the precious metal ion is palladium ion,

(5) The metal plating method according to the above (2), wherein the electroless plating is copper or nickel.

Best Mode for Carrying Out the Invention

The present invention relates to a silane coupling agent used for supporting a precious metal such as Pd, which is a catalyst for electroless plating, on a surface to be plated, or a silane coupling agent having the functional group capable of forming a complex with a noble metal. It is important to use a reaction product of an azole compound having an active functional group with an epoxysilane compound.

Examples of the azole compound include pyrrole, indole, imidazole, pyrazole, benzimidazole, indazole and the like, but are not limited thereto. Moreover, as said epoxysilane type compound, it is a compound which has an epoxy group and an alkoxy silyl group in a molecule | numerator, and generally Glycidoxypropylalkoxysilanes include, but are not limited to. The silane coupling agent itself obtained by the reaction of an azole compound and an epoxy silane compound is already known. For example, Japanese Unexamined Patent Application Publication No. 6-256358 discloses obtaining an imidazole silane compound by reacting an imidazole compound with an epoxy silane; However, the reaction with other azole compounds can be performed in the same manner. Although the silane coupling agent which is this reaction product may be obtained in the state containing the intermolecular and intramolecular condensate, in particular, it is not necessary to separate these and can be used as a mixture. This silane coupling agent is highly reactive, and can adjust to the aqueous solution which has arbitrary concentration by adjusting the acidity of aqueous solution. It also provides some viscosity to the dissolved solution. Therefore, by using this silane coupling agent, the film can be formed uniformly to a certain thickness on the basic surface of the plated object. In addition, electroless plating can be easily performed on various basic surfaces, including a mirror-like surface which was hardly plated with a coupling agent such as a conventional aminosilane or a powder which could not be treated without evaporating a solvent. Examples of the noble metals include palladium, silver, platinum, gold, and the like, which exhibit a catalytic effect in depositing metals such as copper and nickel on the surface of the plated object from the electroless solution. Particularly, palladium is preferable.

According to the metal plating method of the present invention, the plated objects are not limited in their properties. Inorganic materials such as glass and ceramics; Plastic materials such as polyester, polyamide, polyimide and fluororesin; Insulators such as films, sheets, fibers, and insulating plates such as epoxy resins reinforced with glass base materials as necessary; Although it can be applied to the plated material having low conductivity, such as a semiconductor including a Si wafer, the plated material has successfully applied the method of the present invention, including mirrors and powders such as transparent glass plates, Si wafers and other semiconductor substrates. It can be carried out. Examples of such powders include glass beads, molybdenum disulfide powder, magnesium oxide powder, graphite powder, SiC powder, zirconium oxide powder, alumina powder, silicon oxide powder, mica powder, glass fiber, silicon nitride, and teflon powder.

When the electroless plating base surface is treated with a silane coupling agent which is a reaction product of an azole compound and an epoxy silane compound as described above, the silane coupling agent is water, methyl alcohol, ethyl alcohol, It can be dissolved in a suitable solvent such as 2-propanol, acetone, toluene, ethylene glycol, polyethylene glycol or a solvent mixed with them. As for the basic surface of the plate shape, a method of evaporating the solvent after the basic surface coating by immersion treatment or brush application is common, but is not limited thereto. What is necessary is just the method of making a silane coupling agent adhere to a surface uniformly. In addition, for powders, in addition to the method of forcibly evaporating the solvent after the immersion treatment to adhere the silane coupling agent contained in the solution to the surface of the base surface, the silane coupling agent is adsorbed on the base surface in the immersion state due to uniform film formation. Since it is possible, the method of filtering a solvent after a process and drying a wet powder body is also possible.

The concentration of the silane coupling agent in the solution to be treated is not limited thereto, but generally 0.001 to 10% by weight is practical. In the case of less than 0.001% by weight, the amount of the coupling agent adhering to the surface of the base material tends to be low, and effects are hardly obtained. Moreover, when it exceeds 10 weight%, an adhesion amount is too large and it is difficult to dry, or aggregation of a powder tends to occur. To evaporate the solvent used after the surface treatment, it is sufficient to be able to dry the surface by heating above the volatilization temperature of the solvent, but it is preferable to heat-dry at 10 to 60 minutes at 60 to 120 ° C.

The method of chemically plating the surface treated as described above is a known method. In other words, the noble metal is trapped in contact with a solution containing a noble metal ion such as palladium to the azole group of the coupling agent treated on the basic surface. After soluble noble metal salts such as excess halides and solubilizers such as hydrochloric acid, the chemical plating treatment such as electroless plating is performed.

In addition, electroless plating may be performed for the first time to form a metal thin film, and the base surface having no conductivity may have some conductivity, and then electroplating or substitution plating with a nonmetal may be performed.

According to the present invention, metals such as copper, nickel, cobalt, tin, and gold can be plated by electroless plating, but representative examples of the electroless solution used in the present invention include the following.

① Representative example of electroless copper plating composition for high speed and thick plating

CuSO ₄ .5H ₂ O 0.04~0.06 mol / l

EDTA.2Na 0.04-0.12 mol / 1

HCHO (37%) 0.08 to 0.5 mol / 1

pH 12-12.5

Plating temperature 70 ~ 90 ℃

② Representative example of low temperature electroless copper plating composition

CuSO ₄ .5H ₂ O 12.5~14.5g / 1

HCHO (37%) 20-25 g / 1

Rochelle salt 25-40 g / 1

pH 12.2-12.5

Plating temperature 20 ~ 30 ℃

③ Representative example of electroless Ni plating composition as high temperature acid bath

Nickel Sulfate 20-22 g / 1

Lactic acid 25-30 g / 1

Propionic acid 2-3 g / 1

Sodium hypophosphite 20-22g / 1

pH 4.5-5.5

Plating temperature 80 ~ 90 ℃

④ Representative example of electroless Ni plating composition as low temperature ammonia alkaline bath

Nickel Sulfate 24-26 g / 1

Sodium Pyrophosphate 48-52 g / l

Sodium hypophosphite 24-26 g / l

pH 10-11

Plating temperature 55 ~ 65 ℃

The present invention relates to a method of metal plating by electroless plating on a surface having a low conductivity, a mirror surface or a powder, and a metal plating pretreatment therefor.

Example 1

After treating a slide glass plate having a thickness of 1 mm with alkaline degreasing solution, the imidazole and Spin coating was performed at 500 RPM using a 2-propanol solution containing 0.4 wt% of a silane coupling agent, an equimolar reaction product with glycidoxypropyltrimethoxysilane. Then, this board was dried at 105 degreeC for 30 minutes. In addition, it was immersed in Pd activator CG-535A (Activator, manufactured by Nikko Metal Plate Co., Ltd.) for 1 minute at room temperature, washed with about 100 ml of deionized water, dried at 105 ° C for 30 minutes, and activated with precious metal on the surface of the glass plate. It was done. Next, the activated glass plate was immersed at 80 ° C. for 4 minutes in an electroless nickel plating solution, Nicomu 7N (manufactured by Nikko Metal Plating Co., Ltd.). It was confirmed that an electroless nickel plating solution precipitated a gloss film uniformly on the entire glass surface, and had good adhesion without peeling off with a cellophane tape.

Comparative Example 1

After treating the slide glass plate having a thickness of 1 mm with alkaline degreasing solution, it was immersed for 1 minute at room temperature with Pd activator CG-535A without coupling agent treatment on the surface, washed with deionized water at about 100 ml and dried for 30 minutes at 10 ° C. An activation treatment was performed on the surface of the glass plate with a precious metal. Next, the activated glass plate was immersed at 80 ° C. for 4 minutes in an electroless nickel plating solution Nicomu 7N. The electroless nickel plated film hardly precipitated on the glass plate.

Comparative Example 2

A slide glass plate having a thickness of 1 mm was immersed in a hydrofluoric acid and nitric acid mixture (100 ml / L hydrofluoric acid, 100 ml / L nitric acid) at 25 ° C. for 10 minutes to give a rough chemical treatment to the surface. The glass plate was treated with an alkaline degreasing solution, immersed in Pd activating solution CG-535A for 1 minute at room temperature, washed with about 100 ml of deionized water, dried at 105 DEG C for 30 minutes, and activated with a precious metal on the surface of the glass plate. Next, the activated glass plate was immersed at 80 ° C. for 4 minutes in an electroless nickel plating solution Nicomu 7N. The electroless nickel plated film hardly precipitated on the glass plate.

Comparative Example 3

After treating a slide glass plate having a thickness of 1 mm with an alkaline degreasing solution, an aminosilane coupling agent KBM-903 (manufactured by Shin-Etsu Chemical Co., Ltd.) was applied on the glass plate surface. Spinning coating at 500 RPM using a 2-propanol solution containing 0.4% by weight of aminopropyltrimethoxysilane). Then, this board was dried at 105 degreeC for 30 minutes. After immersion in Pd activator CG-535A for 1 minute at room temperature, it was washed with about 100 ml of deionized water, dried at 105 ° C for 30 minutes, and activated on the surface of the glass plate with a precious metal. Subsequently, it was immersed for 4 minutes at 80 degreeC in 7N of electroless nickel plating solutions. Electroless nickel plating deposited only a part of the glass plate.

Comparative Examples 4 and 5

In order to promote the hydrolytic condensation reaction, a small amount of hydrochloric acid was added to a mixture of water and 2-propanol equivalence, and then 4 wt% of the aminosilane coupling agent KBM-903 (0.4 wt% or 10 times its concentration) (Comparative Example 5 ) Was prepared. After conducting the precious metal activation treatment in the same manner as in Comparative Example 3, electroless nickel plating was performed on each activated plate. Both electroless platings deposited only sparse, substantially half of the glass plate.

Example 2

The PET film (trade name; diafoil) was ultrasonically cleaned in 2-propanol for 5 minutes to degrease the surface, and then dried at 105 ° C for 10 minutes. Next, the film is imidazole It was immersed for 1 minute in a 2-propanol solution containing 4% by weight of a silane coupling agent, an equimolar reaction product with glycidoxypropyltriethoxysilane, and dried at 105 ° C for 10 minutes. Further, the plate was immersed in Pd activator CG-535A for 1 minute at room temperature, washed with deionized water, dried at 105 ° C for 10 minutes, and activated on a PET film surface with a precious metal. Next, it was immersed at 72 degreeC for 20 minutes in electroless copper plating solution KC-500 (made by Nikko Metal Plate Co., Ltd.). Electroless copper plating precipitated a uniformly glossy film on the entire PET film surface.

Example 3

With imidazole -Epoxy resin insulating plate (copper-coated laminated plate FR-4 made by Matsushita Denco Co., Ltd.) with a glass-based base material in a 2-propanol solution containing 0.4 wt% of a silane coupling agent which is an equimolar reaction product with glycidoxypropyltrimethoxysilane. The plate from which copper was removed by chemical etching) was immersed for 1 minute and then dried at 105 ° C for 60 minutes. Next, the laminate was immersed in Pd activator CG-535A for 1 minute at room temperature, washed with deionized water, dried at 105 ° C. for 60 minutes, and activated on the surface of the laminate with a precious metal. After the laminate was immersed at 80 ° C. for 2 minutes in the electroless nickel plating solution Nimu 7N, an electroless nickel plating film was uniformly deposited on the laminate. Similarly, when the laminate plate activated with noble metal was immersed in the electroless copper plating solution KC-500 at 70 ° C. for 30 minutes, copper uniformly deposited on the surface.

Comparative Example 6

An epoxy resin insulating plate having a glass foam base material similar to Example 3 was immersed in a solution prepared by adding a small amount of hydrochloric acid to a mixed solution of water and 2-propanol equivalents, and then dissolving 0.4 wt% of an aminosilane coupling agent KBM-903 for 1 minute. Then dried at 105 ° C for 60 minutes. Subsequently, the substrate was immersed in Pd activation liquid CG-535A for 1 minute at room temperature, washed with deionized water, dried at 105 ° C for 60 minutes, and activated on the surface of the laminated plate with a precious metal. After the plate was immersed for two minutes at 80 ° C. in the electroless nickel plating solution Nicomu 7N, an electroless nickel plating film was uniformly deposited on the laminated plate only about 80% of the entire surface.

Example 4

20 g of glass beads having a diameter of about 1.5 mm It was immersed for 1 minute in 50 ml of 2-propanol solution containing 0.08 g of a dissolved silane coupling agent which is an equimolar reaction product with glycidoxypropylmethyldiethoxysilane. The solution was filtered and then dried at 105 ° C. for 30 minutes. After immersing this glass bead in Pd activator CG-535A for 1 minute at room temperature, the activator was filtered, washed with 50 ml of deionized water and dried at 105 ° C for 30 minutes to activate the precious metal on the surface of the glass bead. . The glass beads were immersed at 80 DEG C for 4 minutes in the electroless nickel plating solution Nicomu 7N, and then electroless nickel plating was uniformly deposited on the entire surface of the beads.

Comparative Example 7

Glass beads having a diameter of about 1.5 mm were immersed in 50 ml of 2-propanol solution containing 0.4 wt% of aminosilane coupling agent KBM-903 for 1 minute. After filtering the liquid, the beads were dried at 105 ° C for 30 minutes. After immersing this glass bead in 50 ml of Pd activator CG-535A for 1 minute at room temperature, the activator was filtered, washed with 50 ml of deionized water and dried at 105 ° C. for 30 minutes to activate the precious metal on the surface of the glass bead. It was. After the glass beads were immersed at 80 ° C. for 4 minutes in the electroless nickel plating solution, Nimumu 7N, the electroless nickel plating film was deposited on the bead surface leaving about 30% or more of the unplated bead surface.

Example 5

25 g of molybdenum disulfide powder with an average particle diameter of 50 microns It stirred for 10 minutes at room temperature in 50 ml of 2-propanol solutions which melt | dissolved 0.1 g of silane coupling agents which are equimolar reaction products with-glycidoxy propyl trimethoxysilane. After distilling off the solvent, 2-propanol, the molybdenum disulfide powder was dried at 105 ° C for 60 minutes. The molybdenum disulfide powder was stirred in 50 ml of Pd activator CG-535A at room temperature for 20 minutes, and the activator was filtered off, washed with 50 ml of deionized water, and dried at 105 ° C. for 60 minutes to dry the powder. Activated with precious metals. This molybdenum disulfide powder was plated at 72 ° C using an electroless copper plating solution KC-500. By 1 weight% of electroless copper plating, a uniform copper plating film could be formed on the powder surface, and the molybdenum disulfide which was the basic surface could be completely covered.

Comparative Example 8

Molybdenum disulfide powder with an average particle diameter of 50 microns was stirred in 50 ml of Pd activator CG-535A at room temperature for 20 minutes, and the activator was filtered off, washed with 50 ml of deionized water and dried at 105 ° C. for 60 minutes. The powder surface was activated with a precious metal. Although the molybdenum disulfide powder was plated at 72 DEG C using an electroless copper plating solution KC-500, copper plating films could hardly be formed by this electroless copper plating.

Example 6

50 g of magnesium oxide powder with an average particle diameter of 100 microns It stirred for 10 minutes at room temperature in 100 ml 2-propanol solution which melt | dissolved 0.29 of silane coupling agents which are equimolar reaction products with-glycidoxy propyl triethoxysilane. The solvent, 2-propanol, was distilled off and dried at 105 ° C. for 30 minutes. The magnesium oxide powder was stirred in 100 ml of Pd activator CG-535A at room temperature for 20 minutes, and the activator was filtered off, washed with 100 ml of deionized water and dried at 105 ° C. for 30 minutes to activate a precious metal on the powder surface. Treated. The magnesium oxide powder was plated at 72 ° C using an electroless copper plating solution KC-500. By only 1% by weight of electroless copper plating, a uniform copper plating film could be formed on the powder surface, and magnesium oxide, which was the basic surface, could be completely covered.

Example 7

25 g of natural graphite powder with an average particle diameter of 100 microns was mixed with 2-ethyl-4-methylimidazole. It stirred for 10 minutes at room temperature in 50 ml ethanol solution which melt | dissolved 0.1 g of silane coupling agents which are equimolar reaction products with-glycidoxy propyl trimethoxysilane. After distilling off the solvent, 2-propanol, the graphite powder is dried at 105 ° C for 30 minutes. The graphite powder was stirred in 100 ml of Pd activator CG-535A at room temperature for 20 minutes, and the activator was filtered off, washed with 50 ml of deionized water, dried at 105 ° C. for 30 minutes, and activated with a precious metal on the powder surface. Treated. The graphite powder was plated at 72 ° C using an electroless copper plating solution KC-500. By 6 weight% of electroless copper plating, a uniform copper plating film could be formed on the powder surface. Similarly, when noble metal-activated graphite powder was immersed in the electroless nickel plating solution Nicomu 7N at 80 ° C. for 4 minutes, the electroless nickel plating film was substantially uniformly deposited on the surface, and the powder color changed from black to gray. The base surface could be completely covered with nickel.

Example 8

8 g of SiC powder with an average particle diameter of 70 microns It stirred for 10 minutes at room temperature in 100 ml of methanol solution which melt | dissolved 0.2 g of silane coupling agents which are equimolar reaction products with-glycidoxy propyl trimethoxysilane. Methanol, the solvent, was distilled off and dried at 105 ° C for 30 minutes. The SiC powder was stirred for 20 minutes at room temperature in 100 ml of Pd activator CG-535A, and the activator was filtered, washed with 100 ml of deionized water, dried at 105 ° C. for 30 minutes, and activated with a precious metal on the powder surface. It was. This SiC powder was plated at 72 ° C using an electroless copper plating solution KC-500. By only 1% by weight of electroless copper plating, a uniform copper plating film could be formed on the surface of the powder body, and the powder became completely the same color and completely covered the green SiC powder.

Comparative Example 9

50 g of SiC powder having an average particle diameter of 70 microns was stirred in 100 ml of Pd activator CG-535A for 20 minutes at room temperature. The activator was filtered, washed with 100 ml of deionized water, and dried at 105 DEG C for 30 minutes. The surface was activated with a precious metal. This SiC powder was plated at 72 ° C using an electroless copper plating solution KC-500. The electroless copper plated film could be formed on the powder surface, but could not cover more than 20% of the SiC powder.

Example 9

50 g of zirconium oxide powder having an average particle diameter of 30 microns was mixed with 2-methylimidazole. It was stirred for 10 minutes at room temperature in a 100 ml methanol solution in which 0.2 g of a silane coupling agent which was an equimolar reaction product with glycidoxypropyl triethoxysilane was dissolved. Methanol, the solvent, was distilled off and dried at 105 ° C for 30 minutes. Next, the zirconium oxide powder was stirred for 20 minutes at room temperature in 100 ml of Pd activator CG-535A, the activator was filtered, washed with 100 ml of deionized water, dried at 105 ° C. for 30 minutes, and then noble metal on the powder surface. Activated by. When the zirconium oxide powder was immersed at 80 DEG C for 4 minutes in the electroless nickel plating solution, Nimu 7N, the electroless nickel plating film was precipitated substantially uniformly on the surface of the zirconium oxide, thereby completely covering the basic surface.

Example 10

About 1 g of Teflon yarn with a diameter of 0.3 mm and imidazole It stirred for 10 minutes at room temperature in 250 ml ethanol solution which melt | dissolved 0.02 g of silane coupling agents which are equimolar reaction products with-glycidoxy propyl trimethoxysilane. The solvent, ethanol, was distilled off and dried at 105 ° C. for 30 minutes. After immersing the yarn in 50 ml of Pd activator CG-535A for 20 minutes at room temperature, the activator was filtered, washed with 50 ml of deionized water and dried at 105 ° C. for 30 minutes to activate the precious metal on the surface of the yarn. . When the Teflon yarn was immersed at 80 ° C. for 4 minutes in the electroless nickel plating solution Nicomu 7N, the electroless nickel plating film was uniformly deposited on the yarn surface, and the base surface was completely covered to give the yarn a gray color.

As described above, according to the electroless plating method using the novel metal plating pretreatment agent of the present invention, electroless plating can be preferably performed on mirror-like objects or powders that are difficult to apply in the conventional method. It is not restricted to a characteristic, a shape.

Claims (5)

A metal plating pretreatment agent comprising 0.001 to 10% by weight of a silane coupling agent obtained by a reaction between an azole compound having an active functional group forming a complex with a noble metal ion and an epoxy silane compound. 60 to 60 wt% after treatment of the plated product with a metal plating pretreatment agent containing 0.001 to 10% by weight of a silane coupling agent obtained by the reaction between an azole compound having an active functional group forming a complex with a noble metal ion and an epoxy silane compound. Heat-drying at 120 ° C. for 10 to 60 minutes, immersing the plated product in one of the precious metal ion-containing liquids selected from the group consisting of Pd, Ag, Pt, and Au, and then washing and drying with deionized water to obtain the precious metal. Performing an activation process and immersing the activated plated object in an electroless solution. The metal plating method according to claim 2, wherein the azole compound is imidazole. The metal plating method according to claim 2, wherein the precious metal ion is palladium ion. The metal plating method according to claim 2, wherein the electroless plating is copper or nickel.