JP2003049279A - Additive for accelerator bath solution and accelerator bath solution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an additive for an accelerator bath solution which contains one or more compounds for preventing the suspension of an accelerator bath solution with specified structure, and to provide the accelerator bath solution. SOLUTION: The additive for an accelerator bath solution contains one or more compounds for preventing the suspension of an accelerator bath solution with specified structure. The accelerator bath solution contains the above one or more compounds for preventing the suspension of an accelerator bath solution. In an accelerator treatment stage in an electroless copper plating method, the accelerator bath solution is used, so that the increase of the turbidity of the accelerator bath solution can be suppressed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an accelerator bath liquid additive and an accelerator bath liquid. Also,
The present invention relates to an electroless copper plating method using the accelerator bath solution and a composite material produced by the method.

[0002]

2. Description of the Related Art Generally, in the electroless copper plating method,
The pretreatment step of electroless copper plating is composed of a conditioner step, an etching step, an acid washing step, a palladium tin catalyst applying step, an accelerator processing step, and the like. In the step of applying the catalyst, the palladium tin colloid is adsorbed on the surface of the substrate, and by washing this with water, the adsorbed colloid is hydrolyzed and part of the tin is S.
It becomes a precipitate of n (OH) Cl, other tin elements exist as tetravalent tin, and palladium exists as a palladium salt. In the accelerator treatment step, by treating the substrate with an acid such as hydrochloric acid, sulfuric acid, and borofluoric acid as an accelerator, the tin salt forming the precipitate is dissolved, and the palladium salt that has already been dissolved in the colloidal state The redox reaction with produces metallic palladium. Then, the metallic palladium on the substrate functions as an active catalyst nucleus for the deposition of metallic copper in the electroless copper plating treatment.

[0003]

In the accelerator treatment step of the pretreatment step of electroless copper plating, when the conventional accelerator bath solution containing hydrochloric acid, sulfuric acid, and borofluoric acid as the main components is used, it should be used. As it continues, the turbidity of the accelerator bath liquid increases. The cause has not been completely clarified, but it is possible that the tin element of the palladium tin catalyst adhering to the substrate is liberated into the accelerator bath solution and the tin element is converted to an insoluble compound. Is being considered. Then, the increase in turbidity in the accelerator bath liquid is obtained by performing electrolytic copper plating after electroless copper plating.
Experience has revealed that this is one of the causes of the roughness of the copper layer of the resin composite material. The roughness of the copper layer is particularly remarkable when the electrolytic copper plating treatment has low leveling property. The increase in turbidity of the accelerator bath solution as described above may be such that it becomes unusable in about 1 day during the operation of the normal pretreatment process, and the bath used for other pretreatment processes may be used. Even when compared with the solution, frequent replacement of the bath solution is required, which is a problem in terms of work efficiency and running cost, and a long life of the accelerator bath solution is desired.

The present invention has been made in view of the above circumstances, and suppresses an increase in the turbidity of the accelerator bath solution used in the step of activating the palladium tin catalyst in the electroless copper plating method. Such an additive containing an accelerator bath liquid suspension preventing compound having a specific structure, and an accelerator bath liquid containing the accelerator bath liquid suspension preventing compound, in which an increase in turbidity due to use is suppressed. The purpose is to provide. Also,
The present invention, in the accelerator treatment step of the electroless copper plating method, an electroless copper plating method using an accelerator bath solution containing the accelerator bath solution suspension preventing compound,
And a composite material having a copper thin film produced by the method.

[0005]

SUMMARY OF THE INVENTION The present invention provides an accelerator bath additive containing one or more accelerator bath suspension-preventing compounds having a specific structure, and further comprising an accelerator bath suspension-preventing compound as defined above. An accelerator bath solution containing one or more is provided. Further, the present invention provides an electroless copper plating method using an accelerator bath solution containing the accelerator bath solution suspension-preventing compound in an accelerator treatment step of the electroless copper plating method, and a composite material produced by the method. .

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the accelerator bath suspension-preventing compound in the present invention include cysteine, cystine, thiomalic acid, methionine, thiodisuccinic acid, oxalic acid,
Hydroxyacetic acid, glyoxylic acid, lactic acid, itaconic acid,
2-pyrrolidone-5-carboxylic acid, ascorbic acid, hydroquinone, aminopyrazine, 3-amino-1H-1,
2,4-triazole, thiourea, urea, adenine, guanidine, allantoin, 2-amino-5-methyl-
1,3,4-thiadiazole, hydroxylamine, cystamine, hydrazine, 1- (2,3-dihydroxypropyl) benzotriazole, 2-imidazolidinone,
o-toluidine-4-sulfonic acid, 1,3-phenylenediamine-4-sulfonic acid, sulfosalicylic acid, phenolsulfonic acid, phosphoric acid, phosphonic acid, hydroxyethylidene diphosphonic acid, boric acid and tetraboric acid, and these Included are salts of the compounds. Preferably, the accelerator bath suspension-preventing compound is cysteine, cystine, thiomalic acid, methionine, thiodisuccinic acid, oxalic acid, hydroxyacetic acid, glyoxylic acid, lactic acid, itaconic acid, 2-pyrrolidone-5-carboxylic acid, ascorbic acid. And hydroquinone, and compounds selected from the group consisting of salts of these compounds. More preferred are cysteine, cystine, thiomalic acid, methionine, thiodisuccinic acid and ascorbic acid, and salts of these compounds. Even more preferred are cysteine, cystine and thiomalic acid, and salts of these compounds, most preferred are thiomalic acid and its salts. Further, preferably, as the accelerator bath suspension preventing compound, aminopyrazine, 3
-Amino-1H-1,2,4-triazole, thiourea, urea, adenine, guanidine, allantoin, 2-
Amino-5-methyl-1,3,4-thiadiazole, hydroxylamine, cystamine, hydrazine, 1-
Mention may be made of compounds selected from the group consisting of (2,3-dihydroxypropyl) benzotriazole and 2-imidazolidinone, and salts of these compounds. More preferably, aminopyrazine, 3-amino-1H-1,
2,4-triazoles, thioureas, ureas and adenines, and salts of these compounds are mentioned. Further, preferably, as the accelerator bath liquid suspension preventing compound, o-toluidine-4-sulfonic acid, 1,3-phenylenediamine-4-sulfonic acid, sulfosalicylic acid, phenolsulfonic acid, phosphoric acid, phosphonic acid, hydroxy Included are compounds selected from the group consisting of ethylidene diphosphonic acid, boric acid and tetraboric acid, and salts of these compounds. More preferably, hydroxyethylidene diphosphonic acid and its salt are mentioned.

As the salt of the accelerator bath suspension suspending compound described above, any salt which can be formed by each compound and which is water-soluble can be used, and the compound is a carboxyl group, a sulfonic acid group or a phosphoric acid group. In the case of having a phosphonic acid group and / or a boric acid group, the substance forming a salt with these acid groups may be any substance as long as it is not against the object of the present invention. For example, the salt formed can be, but is not limited to, alkali metal salts, alkaline earth metal salts, ammonium salts, and the like. Further, when the compound has a primary, secondary or tertiary amine structure, these amines have a quaternary ammonium structure, and a salt form formed with the ammonium and an acid is possible, and in the case of hydrazine, It can be in the form of a salt formed with hydrazinium and an acid. here,
As the acid forming a salt, any acid can be used as long as it does not violate the object of the present invention, for example, hydrochloric acid, sulfuric acid, phosphoric acid,
Examples include nitric acid and the like, but the invention is not limited thereto. The water-solubility here is sufficient as long as it is water-soluble to such an extent that it can be dissolved in the accelerator bath liquid.

The additive for accelerator bath liquid in the present invention contains at least one of the above accelerator bath liquid suspension preventing compounds. The accelerator bath additive is
By including an accelerator bath suspension suspension compound,
When added to the accelerator bath solution, the increase in turbidity of the accelerator bath solution can be suppressed. Without wishing to be bound by theory, the increase in turbidity of the accelerator bath solution is
By immersing the substrate to which the palladium tin catalyst has been added in the accelerator bath liquid, the tin element liberated from the substrate is converted into an insoluble compound in the accelerator bath liquid to form a suspension, which reduces the turbidity of the accelerator bath liquid. It is supposed to raise. Although not wishing to be bound by theory, as the mechanism for suppressing the increase in the turbidity of the accelerator bath solution by the accelerator bath solution suspension preventing compound in the present invention, the accelerator bath solution suspending compound is, It is considered that it forms a chelate with the tin ions in the accelerator bath liquid and prevents the conversion to an insoluble compound.

The accelerator bath additive of the present invention is
An acid other than the accelerator solution suspension preventing compound may be further included. The acid may be any acid as long as it is an acid other than the accelerator solution suspension-preventing compound, and examples thereof include hydrochloric acid, sulfuric acid, borofluoric acid, and alkylsulfonic acid, but are not limited thereto. is not. Also, two or more kinds of acids may be mixed and contained. Preferably, the acid other than the accelerator solution suspension inhibiting compound is an alkyl sulfonic acid, more preferably methane sulfonic acid. When the accelerator bath additive of the present invention contains an acid other than the accelerator bath suspension inhibitor, the ratio of the amounts of the accelerator bath suspension inhibitor and the acid other than the accelerator solution suspension inhibitor is as follows. , An arbitrary ratio is possible, but when added to the accelerator bath solution, the accelerator bath solution suspension-preventing compound is in an amount such that it exerts a suspension-preventing effect, and an acid other than the accelerator solution suspension-preventing compound is used. Is preferably the amount of acid required for the accelerator treatment.
Further, the additive for accelerator bath liquid of the present invention may further contain a nonionic surfactant. Any nonionic surfactant can be used as long as it is not against the object of the present invention. Examples of the nonionic surfactant include polyethylene glycol, polyoxyethylene alkylphenol, polyoxyethylene styrenated phenol, polyoxypropylene polyoxyethylene polymer, and glycerin. The nonionic surfactant may be contained alone or in a mixture of two or more kinds.

The accelerator bath additive of the present invention is
As long as it contains an acid and / or a nonionic surfactant other than the accelerator solution suspension-preventing compound and optionally the accelerator bath solution suspension-preventing compound, it may be composed of only these components, or water, etc. It may be in a state of being dissolved in an appropriate solvent.

The accelerator bath liquid of the present invention is an aqueous solution containing an accelerator bath liquid suspension preventing compound and an acid other than the accelerator bath liquid suspension preventing compound. The accelerator bath liquid suspension prevention compound is as described above, and may contain one kind of accelerator bath liquid suspension prevention compound, or may contain two or more kinds of accelerator bath liquid suspension prevention compound. May be. The amount of the accelerator bath liquid suspension preventing compound contained in the accelerator bath liquid of the present invention is appropriately set depending on the use conditions of the accelerator bath liquid, the type of accelerator bath liquid suspension preventing compound used, and the like. Generally, 0.001
g / L to 50 g / L, preferably 0.0
It is from 05 g / L to 10 g / L.

As the acid other than the accelerator bath solution suspension preventing compound contained in the accelerator bath solution of the present invention, any acid usually used in the accelerator treatment step can be used, and examples thereof include hydrochloric acid, sulfuric acid and hydrogen borofluoride. Examples thereof include acids and alkylsulfonic acids, but are not limited thereto. Moreover, you may mix and contain the acid of 2 weeks or more. Preferably, the acid other than the accelerator solution suspension inhibiting compound is an alkyl sulfonic acid, more preferably methane sulfonic acid. As the amount of the acid other than the compound for preventing suspension of the accelerator bath solution contained in the accelerator bath solution, the amount of the acid used in the usual accelerator treatment step is used, but generally 25 g / L.
-100 g / L, preferably 40 g / L-60
It is g / L.

The accelerator bath solution of the present invention may further contain a nonionic surfactant. As the nonionic surfactant, any substance can be used as long as it does not interfere with the accelerator treatment step. Examples of the nonionic surfactant include polyethylene glycol, polyoxyethylene alkylphenol, polyoxyethylene styrenated phenol, polyoxypropylene polyoxyethylene polymer, and glycerin. The nonionic surfactant may be contained alone or in a mixture of two or more kinds. The amount of nonionic surfactant that can be contained in the accelerator bath solution of the present invention is generally 0.001 g / L to 20.
g / L, preferably 0.01 g / L to 15 g /
It is L.

The accelerator bath solution of the present invention can be applied to any known electroless copper plating method as long as it has an accelerator step for activating a palladium tin catalyst. The accelerator bath liquid of the present invention is used in the accelerator treatment step of activating the palladium tin catalyst in the electroless copper plating method,
It is possible to suppress an increase in turbidity associated with use in a conventional accelerator bath solution. The accelerator treatment step of the electroless copper plating method is performed by bringing a substrate having a palladium tin catalyst on its surface into contact with an accelerator bath solution. Any method can be used for contacting the substrate with the accelerator bath solution of the present invention, for example, by immersing the substrate in the accelerator bath solution,
Alternatively, a method of spraying the accelerator bath liquid on the substrate may be mentioned, but the method is not limited thereto. Bath temperature,
The processing time can also be set as appropriate based on known and conventional conditions.

As the palladium tin catalyst used in the electroless copper plating method, a known commercially available palladium tin catalyst can be used. The catalyst used is in the form of a catalyst liquid in which the palladium tin catalyst is present as a colloid in the medium.

The substrate that can be used in the electroless copper plating method has appropriate physical properties according to the purpose of use, for example,
The substrate is not particularly limited as long as it has strength, corrosion resistance, etc., and can be a substrate made of any resin and having any shape. Preferably, the base is a resin base, and the resin base is not limited to a resin molded product, and may be a composite in which a reinforcing material such as a glass fiber reinforcing material is interposed between resins, or a ceramic, Glass,
A resin thin film may be formed on a base material made of various materials such as metal. The resin substrate may be made of a single resin, or may be made of a plurality of resins. Further, it may be a composite in which a resin is applied or laminated on another substrate.

In the electroless copper plating method of the present invention,
First, a palladium tin catalyst is attached on the substrate. As the method for depositing the catalyst, any method may be used as long as the catalyst deposits on the substrate, and examples thereof include a method of immersing the substrate in the catalyst solution or a method of spraying the catalyst solution on the substrate. However, the present invention is not limited to these. Before the catalyst is applied to the substrate, if necessary, for example, by dipping and spraying the substrate in a commonly used conditioner, it is possible to easily attach the palladium or palladium-tin catalyst on the substrate. It is also possible to perform conditioning treatment, etching treatment, and the like.

In the electroless copper plating method of the present invention,
By the accelerator treatment, metallic palladium is produced on the substrate, and the metallic palladium functions as an active catalyst nucleus for deposition of metallic copper in the electroless copper plating treatment, and by treatment with the electroless copper plating solution, it is deposited on the resin substrate. A copper thin film is directly formed to obtain a copper-resin composite material. Although not wishing to be bound by theory, in the electroless copper plating method using the accelerator bath solution of the present invention, since suspension of the accelerator bath solution is prevented, the suspension of the accelerator is one of the causes. It is considered that it is possible to prevent the roughness of the deposited copper layer after the electrolytic copper plating treatment, which is considered to be possible.
As the electrolytic copper plating method, any known electrolytic copper plating method such as copper sulfate plating, copper cyanide plating, and copper pyrophosphate plating can be used. Copper sulfate plating is preferred. Hereinafter, examples will be described to describe the present invention in more detail, but the examples do not limit the scope of the present invention.

[0019]

EXAMPLES Comparative Example 1 Suspension of Accelerator Bath Solution Using Palladium Tin Catalyst 48 g / L of methanesulfonic acid and nonionic surfactant 7.35 g / L of these compounds were dissolved in pure water to prepare an accelerator bath. A liquid was created. A palladium tin catalyst suspension (palladium element concentration 0.15 g / L, tin element concentration 3.9) was added to 200 mL of the accelerator bath solution.
g / L) is 0% (without addition), 0.5% (palladium concentration in the final accelerator bath solution is 0.75) by volume ratio.
mg / L, tin concentration 19.5 mg / L), 1.0% (final concentration of palladium in accelerator solution: 1.5 m
g / L, tin concentration 39 mg / L), 1.5% (palladium concentration in final accelerator bath liquid 2.25 mg / L)
L, tin concentration 58.5 mg / L) or 5.0% (final accelerator bath solution palladium concentration 7.5 mg
/ L, tin concentration 195 mg / L),
After stirring for 1 hour (catalyst concentration 0 to 1.5%) or standing for 1 hour and standing still for 18 hours (catalyst concentration 5%), the turbidity of the accelerator bath solution was measured. Turbidity meter (made by HACH; MODEL 2100)
A), and the result is the NTU unit (nephelometer turbidity unit; JIS K0101-1988 “Industrial water test method”, Section 9.2) , Formazin standard solution "4.
"00 degree formazine" corresponds to 400 NTU. ). Example 1 Suspension Inhibitory Effect of Accelerator Bath Liquid Suspension Preventing Compound To the accelerator bath liquid having the composition of Comparative Example 1, the accelerator bath liquid suspending preventing compound shown in Table 1 was added at the concentration shown in Table 1, The accelerator bath solution of Example 1 was prepared for each compound. The turbidity of this accelerator bath liquid was measured by the same method as in Comparative Example 1. Comparative Example 2 Compounds Not Showing Suspension Inhibitory Effect To the accelerator bath solution having the composition of Comparative Example 1, the compounds shown in Table 1 were added at the concentrations shown in Table 1 to prepare an accelerator bath solution of Comparative Example 2. . The turbidity of this accelerator bath liquid was measured by the same method as in Comparative Example 1.
As described above, the results of Comparative Examples 1 and 2 and Example 1 are shown in Table 1.
Shown in.

[0020]

[Table 1]

In Comparative Example 1, the turbidity of the accelerator bath liquid increased as the concentration of the palladium tin catalyst in the accelerator bath liquid increased. On the other hand, among the compounds of Example 1, No. The compounds 1-4, 7, 8, 10 and 13 showed the effect of suppressing the increase in turbidity at all the concentrations of the palladium tin catalyst studied. In addition, in the compounds of Example 1 other than these, suppression of turbidity increase at all concentrations was not observed, but suppression of turbidity increase at specific palladium tin catalyst concentrations was observed. On the other hand, in the compound of Comparative Example 2, at any concentration of the palladium tin catalyst,
No effect of suppressing the increase in turbidity was observed. From this, it was clarified that the accelerator solution suspension-preventing compound of the present invention suppresses the increase in the turbidity of the accelerator solution due to the palladium tin catalyst.

Example 2 Suspension Inhibitory Effect of Accelerator Bath Solution Suspension Preventing Compound For thiomalic acid, cysteine, cystine, hydroxyethylidene diphosphonic acid and thiodisuccinic acid, the concentrations of these compounds were changed to change the turbidity of the accelerator bath solution. The effect of suppressing the rise was examined. Except for changing the concentration of each compound and the concentration of palladium tin catalyst, the stirring time,
The test was conducted in the same manner as in Example 1 above. The stirring time was 1 hour when the catalyst concentration was 0 to 1.5%, or 1 hour after standing for 18 hours when the catalyst concentration was 5% or more.
The results are shown in Table 2. Further, in Table 2, Comparative Example 1 is shown as a control group.

[0023]

[Table 2]

It was found that for all the compounds evaluated in Example 2, the effect of suppressing turbidity also improved as the concentration of the compound increased. Further, even with these compounds, the turbidity of the accelerator bath liquid tended to increase as the concentration of the palladium tin catalyst increased.

Comparative Example 3 Adsorption of Palladium Tin Catalyst on Substrate A substrate obtained by etching away the copper foil of a copper clad laminate (epoxy resin substrate FR-4; manufactured by Hitachi Chemical Co., Ltd., MC
LE-67) was cut into 5 cm square pieces, dried, and the size of the substrate was measured. After measuring the size, the substrate was treated with a cleaner conditioner for 5 minutes, washed with hot water and washed with water for 1 minute each, treated with 10% sulfuric acid for 1 minute, and then washed with water for 2 minutes. Pre-dip the substrate to 1.5
After the treatment for a minute, the catalyst was immersed in a palladium tin catalyst solution containing 0.15 g / L of palladium and 3.9 g / L of tin for 5.5 minutes. After the catalyst adhesion treatment, the substrate is washed with water for 2 minutes,
The substrate was immersed in an accelerator bath solution at 0 ° C. 5.
The substrate was taken out after 5 or 8 minutes, and the amounts of elemental palladium and tin present on the substrate were measured by a high frequency inductively coupled plasma analyzer. The accelerator bath liquid was prepared by dissolving these compounds in pure water so that the concentration of methanesulfonic acid was 48 g / L and the nonionic surfactant was 7.35 g / L. The method for measuring the amount of palladium element or tin element adsorbed on the substrate is as follows. About 8 mL of aqua regia was added to the treated substrate and heated. After boiling, the obtained base solution was transferred to a measuring flask, and the volume was raised to 100 mL with pure water. The base solution was analyzed with a high frequency inductively coupled plasma analyzer to quantify the amounts of palladium element and tin element. The amount of palladium element or tin element adsorbed on the substrate is
It is represented by the amount of elemental palladium or tin (μg / cm ² ) per surface area of the substrate. Example 3 Effect of Accelerator Bath Liquid Suspension Preventing Compound of the Present Invention on Adsorption of Palladium Tin Catalyst on Substrate The accelerator bath liquid of Comparative Example 3 contained thiomalic acid, cysteine, phosphoric acid, hydroxyacetic acid, hydroquinone, ascorbic acid or A substrate on which an accelerator bath liquid and a palladium tin catalyst were adsorbed was prepared by the same method as in Comparative Example 3 except that aminopyrazine was contained in the concentration shown in Table 3, and the substrate was treated with the same method after the accelerator treatment by the same method. The amount of elemental palladium and elemental tin present was measured. The results of Comparative Example 3 and Example 3 are shown in Table 3. Remaining% in the table represents the amount of palladium element or tin element after the treatment in% when the amount of palladium element or tin element before the accelerator treatment is 100%. The difference in the amount of palladium element and the amount of tin element before the treatment is due to the fact that another experiment was performed.

[0026]

[Table 3]

As is clear from the results of Comparative Example 3, the amount of tin element existing on the substrate was reduced by the accelerator treatment, and the amount of palladium element was slightly reduced, but some amount remained. . From this,
In the accelerator treatment, the tin element is released from the substrate due to the redox reaction between the palladium tin elements, whereby the palladium element remaining on the substrate is metallic palladium that can function as an active catalyst nucleus in the electroless copper plating treatment. It is suggested that it exists as a form of. Further, when thiomalic acid, L-cysteine, ascorbic acid and hydroquinone were added, the amount of tin element remaining in the substrate was reduced, suggesting that a redox reaction between palladium tin elements is occurring. In addition, the reduction of the amount of palladium element remaining on the substrate was suppressed as compared with Comparative Example 3. From these facts, it is considered that these compounds are suppressed in liberation of palladium element into the accelerator bath solution, and are excellent in the effect of preventing suspension and also in the efficiency of forming palladium active catalyst nuclei. . Further, with respect to hydroxyacetic acid and aminopyrazine, reduction of tin element and palladium element to the same extent as in Comparative Example 3 was observed, which indicates that redox reaction occurred between palladium tin elements in the accelerator treatment. It is suggested that the residual palladium element exists in the form of metallic palladium that can function as an active catalyst nucleus in the electroless copper plating treatment. On the other hand, for phosphoric acid, almost no reduction of the tin element is observed, and therefore, when phosphoric acid is included, it is suggested that the accelerator bath liquid has a weak function as an accelerator.

Example 4 Effect of Thiomalic Acid on Adsorption of Palladium Tin Catalyst on Substrate The same method as in Example 3 except that thiomalic acid was used as an accelerator bath suspension suspension compound and its concentration was changed. The adsorption amounts of palladium element and tin element on the substrate after the accelerator treatment were measured. Comparative Example 4 The adsorption amounts of palladium element and tin element on the substrate after the accelerator treatment were measured by the same method as in Example 4 except that the accelerator bath solution suspension preventing compound was not included. Comparative Example 5 In the same manner as in Example 4, except that sulfuric acid, which is known to accelerate the palladium tin catalyst, was used as the accelerator bath solution containing 0.25 mol / L, after the accelerator treatment. The amount of adsorption of palladium element and tin element on the substrate was measured. The results of Example 4 and Comparative Examples 4 and 5 are shown in Table 4.

[0029]

[Table 4]

As is clear from Example 4, from the concentration of 0.002 g / L, thiomalic acid exhibited the effect of reducing the amount of residual tin element and the effect of maintaining the residual palladium element. Further, when sulfuric acid was used, the remaining tin element was reduced and the reduction of palladium element was also confirmed.

Example 5 Effect of Thiomalic Acid on Adsorption of Palladium Tin Catalyst on Substrate The treatment time in the accelerator bath solution and the concentration of thiomalic acid were changed, and the temperature of the accelerator bath solution was 40 ° C. or 30 ° C. The adsorption amounts of palladium element and tin element on the substrate after the accelerator treatment were measured by the same method as in Example 4 except that Comparative Example 6 The amounts of palladium element and tin element adsorbed on the substrate after the accelerator treatment were measured by the same method as in Example 5 except that the accelerator bath solution suspension preventing compound was not included. The results of Example 5 and Comparative Example 6 are shown in Table 5.

[0032]

[Table 5]

As is clear from Comparative Example 6, the bath temperature was 3
At both 0 and 40 ° C., a reduction in the amount of residual tin element and a reduction in the residual palladium element were observed after 3 minutes from the accelerator bath solution treatment. Further, as is clear from Example 5, under the condition that the treatment time was 3 minutes and the bath temperature was 30 ° C. and 40 ° C.,
A reduction in the amount of remaining tin element was observed, and the effect of maintaining the palladium element was improved as compared with Comparative Example 6.

Example 6 Examination of Adsorption Effect in Accelerator Bath Solution Containing Tin Element 0.05 g / L of thiomalic acid was adopted as a compound for preventing suspension of accelerator bath solution, and palladium tin catalyst solution was added to the accelerator bath solution. A bath solution was prepared. The added palladium tin catalyst solution was palladium: tin = 7:
It was contained in a weight ratio of 10000, and the addition amount was 0 to 10 mg / L as the tin concentration in the bath liquid. Also,
The bath temperature was 30 ° C. and the treatment time was 5.5 minutes. Except for these points, the amounts of palladium element and tin element adsorbed on the substrate after the accelerator treatment were measured by the same method as in Example 5. Comparative Example 7 The adsorption amounts of palladium element and tin element on the substrate after the accelerator treatment were measured by the same method as in Example 6 except that thiomalic acid was not included. The results of Example 6 and Comparative Example 7 are shown in Table 6.

[0035]

[Table 6]

In Example 6 and Comparative Example 7, tin element and palladium element were added to the accelerator bath liquid. This test system is a model of the accelerator bath solution used for a certain period of time because the amount of tin element and elemental palladium in the bath increases when the use of the accelerator bath solution is actually continued. In Comparative Example 7, the amount of elemental palladium remaining after the treatment varied due to the variation in the amount of the catalyst added. On the other hand, in Example 6, even if the amount of the catalyst added varied, the amount of the residual palladium element hardly changed. Normally, in an accelerator bath used on an industrial level, the bath solution is exchanged when the tin concentration in the bath solution reaches about 30 mg / L, although it varies depending on use conditions and the like. Therefore, it is desirable that the palladium adsorption amount does not fluctuate in the tin concentration range of 0 to 30 mg / L. The accelerator bath solution of the present invention has a constant palladium adsorption amount within this range, and changes in the amount of palladium element adsorbed on the substrate even if the tin and palladium contents in the bath solution change due to use at an industrial level. It became clear to suppress.

[0037]

As described above, the accelerator bath solution of the present invention contains the accelerator bath solution suspension-preventing compound, which is a problem in the conventional accelerator bath solution. It has the effect of suppressing an increase in the turbidity of the bath liquid. Also,
When the turbidity increase of the accelerator bath liquid is considered to be one of the causes for suppressing such an increase in turbidity, an electrolytic copper plating process after the electroless copper plating process, particularly, an electrolytic copper plating process with low leveling property is performed. The resulting copper-resin composite material has the effect of preventing roughness of the deposited copper layer. Further, the accelerator bath liquid of the present invention has the effect of preventing the reduction of the adsorption amount of the palladium catalyst.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takashi Kanda             3-15-17 Teraodai, Niigata City, Niigata Prefecture F-term (reference) 4K022 AA02 AA11 BA08 CA04 CA06                       CA21 CA22 DA01

Claims (14)

[Claims] 1. Cysteine, cystine, thiomalic acid,
Methionine, thiodisuccinic acid, oxalic acid, hydroxyacetic acid, glyoxylic acid, lactic acid, itaconic acid, 2-pyrrolidone-5-carboxylic acid, ascorbic acid, hydroquinone,
Aminopyrazine, 3-amino-1H-1,2,4-triazole, thiourea, urea, adenine, guanidine, allantoin, 2-amino-5-methyl-1,3,4-thiadiazole, hydroxylamine, cystamine, hydrazine , 1- (2,3-dihydroxypropyl) benzotriazole, 2-imidazolidinone, o-toluidine-4-sulfonic acid, 1,3-phenylenediamine-4-
An accelerator bath suspension suspending compound selected from the group consisting of sulfonic acid, sulfosalicylic acid, phenolsulfonic acid, phosphoric acid, phosphonic acid, hydroxyethylidene diphosphonic acid, boric acid and tetraboric acid, and salts of these compounds. Additive for accelerator solution containing. 2. Cysteine, cystine, thiomalic acid,
Accelerator bath suspensions selected from the group consisting of methionine, thiodisuccinic acid, oxalic acid, hydroxyacetic acid, glyoxylic acid, lactic acid, itaconic acid, 2-pyrrolidone-5-carboxylic acid, ascorbic acid and hydroquinone, and salts of these compounds. Additive for accelerator bath liquid containing anti-turbidity compound. 3. Aminopyrazine, 3-amino-1H-
1,2,4-triazole, thiourea, urea, adenine, guanidine, allantoin, 2-amino-5-methyl-1,3,4-thiadiazole, hydroxylamine, cystamine, hydrazine, 1- (2,3-dihydroxy Propyl) benzotriazole and 2-imidazolidinone, and an accelerator bath liquid additive containing an accelerator bath liquid suspension-preventing compound selected from the group consisting of salts of these compounds. 4. O-toluidine-4-sulfonic acid, 1,
3-phenylenediamine-4-sulfonic acid, sulfosalicylic acid, phenolsulfonic acid, phosphoric acid, phosphonic acid,
An additive for an accelerator bath solution containing an accelerator bath solution suspension-preventing compound selected from the group consisting of hydroxyethylidene diphosphonic acid, boric acid and tetraboric acid, and salts of these compounds. 5. The additive for an accelerator bath liquid according to claim 1, further comprising an acid other than the accelerator bath liquid suspension preventing compound, and / or a nonionic surfactant. 6. Cysteine, cystine, thiomalic acid,
Methionine, thiodisuccinic acid, oxalic acid, hydroxyacetic acid, glyoxylic acid, lactic acid, itaconic acid, 2-pyrrolidone-5-carboxylic acid, ascorbic acid, hydroquinone,
Aminopyrazine, 3-amino-1H-1,2,4-triazole, thiourea, urea, adenine, guanidine, allantoin, 2-amino-5-methyl-1,3,4-thiadiazole, hydroxylamine, cystamine, hydrazine , 1- (2,3-dihydroxypropyl) benzotriazole, 2-imidazolidinone, o-toluidine-4-sulfonic acid, 1,3-phenylenediamine-4-
Of an accelerator bath suspension inhibiting compound selected from the group consisting of sulfonic acid, sulfosalicylic acid, phenolsulfonic acid, phosphoric acid, phosphonic acid, hydroxyethylidene diphosphonic acid, boric acid and tetraboric acid, and salts of these compounds. An accelerator bath liquid containing one or more, and an acid other than the accelerator suspension liquid-preventing compound. 7. Cysteine, cystine, thiomalic acid,
Accelerator bath suspensions selected from the group consisting of methionine, thiodisuccinic acid, oxalic acid, hydroxyacetic acid, glyoxylic acid, lactic acid, itaconic acid, 2-pyrrolidone-5-carboxylic acid, ascorbic acid and hydroquinone, and salts of these compounds. An accelerator bath solution containing one or more turbidity-preventing compounds and an acid other than the accelerator suspension suspension compound. 8. Aminopyrazine, 3-amino-1H-
1,2,4-triazole, thiourea, urea, adenine, guanidine, allantoin, 2-amino-5-methyl-1,3,4-thiadiazole, hydroxylamine, cystamine, hydrazine, 1- (2,3-dihydroxy Propyl) benzotriazole and 2-imidazolidinone, and one or more accelerator bath suspension inhibiting compounds selected from the group consisting of salts of these compounds,
And an accelerator bath solution containing an acid other than the accelerator suspension suspension compound. 9. O-toluidine-4-sulfonic acid, 1,
3-phenylenediamine-4-sulfonic acid, sulfosalicylic acid, phenolsulfonic acid, phosphoric acid, phosphonic acid,
Hydroxyethylidene diphosphonic acid, boric acid and tetraboric acid, and one or more accelerator bath solution suspension preventing compounds selected from the group consisting of salts of these compounds, and an acid other than the accelerator bath solution suspending prevention compound. Accelerator bath liquid containing. 10. The accelerator bath liquid according to claim 6, wherein the acid other than the accelerator suspension liquid preventing compound is an alkylsulfonic acid. 11. The accelerator bath liquid according to claim 6, further comprising a nonionic surfactant. 12. The accelerator bath liquid according to claim 6, which contains an accelerator bath suspension suspending compound at a concentration of 1 mg / L to 50 g / L. 13. An electroless copper plating method using the accelerator bath solution according to claim 6 in an accelerator treatment step of activating a palladium tin catalyst in the electroless copper plating method. 14. A composite material produced by the electroless copper plating method according to claim 13.