JP2003013278A - Gold plating solution - Google Patents

Abstract

(57) [Abstract] (with correction) [PROBLEMS] To provide a gold plating solution capable of removing impurity metals, particularly copper ions, accumulated in the gold plating solution by contact with a chelating resin. A gold plating solution containing a gold salt, a conductive salt, a crystal modifier and a complexing agent, wherein a complex constant between an impurity metal ion accumulated in the gold plating solution and the complexing agent is a chelate. When the complex constant between the resin and the impurity metal ion is smaller than that, the impurity ion is adsorbed and removed by the chelating resin, but the gold salt and the crystal modifier are not adsorbed. Examples of the chelate resin include those having an iminodiacetic acid type coordination group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gold plating solution, and more particularly to a gold plating solution used for connecting terminals of electronic parts.

[0002]

2. Description of the Related Art Gold plating is widely used for the purpose of protecting the surface of connecting terminals of electronic parts because of the excellent corrosion resistance, heat resistance, mechanical properties, and electrical properties of gold films. It has become an indispensable material for guaranteeing sex.

There are various types of substrates for electronic parts for which gold plating is used, such as plastics, ceramics and metals. In recent years, as electronic parts have become higher in density and lighter in weight,
The demand for film substrates is increasing. The film substrate is also called a flexible substrate and can be bent freely and requires a small space for mounting, and is therefore often used for small electronic components. The flexible substrate is, for example, laminated resin film and copper foil,
It is obtained by forming an electronic circuit of copper on the original film obtained by vacuum-treating copper on a resin film using lithography technology, then gold-plating the terminal part and mounting electronic parts here. ing.

Such a flexible substrate and conventional plastics, ceramics, called rigid substrates,
The process of forming gold plating may be different from that of a substrate made of metal or the like. In a rigid board, a nickel plating layer is first formed on a copper foil, and then gold plating is performed on this, but in a flexible board, it is possible to directly perform gold plating on a copper foil without forming a nickel plating layer. Many.
This is because nickel has a high hardness and is easily broken when the substrate is bent.

Therefore, in a flexible board in which the board is bent, gold plating is directly performed on the copper foil without forming a nickel plating layer.

However, when gold plating is directly performed on a copper foil without forming a nickel plating layer in this way, a large amount of copper is eluted in the plating solution, and copper ions accumulate with the amount of plating work. There arises a problem that the current efficiency of the plating solution, the current density, the purity of gold plating, etc. are reduced. When gold is plated on nickel like a rigid board, nickel ions will be accumulated in the plating solution instead. The impact is minor.

As described above, the demand for flexible substrates is increasing in recent years, and the nickel plating layer is omitted in such a flexible substrate, and the elimination of the nickel plating layer causes the accumulation of copper ions in the gold plating solution. And the effect of copper ions on gold plating is so large that it cannot be ignored, it is possible to perform gold plating directly on a copper plate and selectively remove the copper ions etc. that accumulate with it. Possible gold plating solutions have been sought, especially from the flexible substrate industry.

As a matter of course, when removing the metal ions as impurities, the gold in the gold plating solution must not be removed, and the physical properties of the gold plating formed by the treated gold plating solution must be removed. Must not change.

Here, the current efficiency is expressed by the weight of gold deposited, which weight of gold is deposited as a film from the plating solution when electroplating is performed by applying a constant current. . When the current efficiency decreases, it becomes difficult to obtain a predetermined gold plating film thickness even if a constant amount of current is passed. If the gold plating film of electronic parts becomes thin, corrosion resistance, heat resistance, mechanical properties, etc. become insufficient, and as a result, the number of cases where electronic parts do not pass the standard increases, so even if it is used for a long time, the current efficiency There is a demand for a gold plating solution that does not deteriorate. In addition, the current density is a value in which the current that can be applied to a certain area of an object to be plated (for example, a substrate) is displayed in A / dm ² . If the current density during plating is higher than the permissible amount, a phenomenon called "burning" occurs. The "burnt" surface on the plating surface is not uniform and the color tone of the plating becomes reddish, and the characteristics of the plating surface deteriorate and the product fails. Therefore, a plating solution having a narrow operating current density range often causes a decrease in product yield due to burning. Therefore, in order to carry out plating without causing burns, it is necessary to reduce the current density, and it takes time to obtain a predetermined plating thickness, resulting in low productivity.

Further, the purity of the deposited gold plating also greatly affects the physical properties of the gold plating. In the case of gold plating for semiconductor bonding, a purity of 99.99% or higher is indispensable, and suppressing the accumulation of impurity ions co-deposited is important for managing the gold plating solution. Examples of the impurity metal to be co-deposited include iron, nickel, cobalt, copper and the like, but it is copper that has a large influence on the bonding physical properties due to a small amount of co-deposited metal. FIG. 1 shows the relation between the concentration of impurity ions accumulated in the gold plating solution, ppm, and the rate of occurrence of defective bonding of the deposited gold plating. I understand.

[0011]

In order to solve these problems, various absorbents and methods for removing interfering metals using these absorbents have hitherto been attempted. However, in the conventional method, not only the interfering metal accumulated in the gold plating solution but also the gold salt and the crystal modifier which are the main components of the plating solution are often adsorbed, and as far as the present inventors know, No satisfactory results were obtained. For example, when treated with an ion exchange resin to remove copper, iron and chromium, there was a problem that gold, which is a main component of the plating solution, was also adsorbed. In addition, even if a chelate resin that selectively adsorbs a specific metal ion is used, the target metal is not adsorbed or not adsorbed depending on the composition of the gold plating, and the chelate resin has not yet been effectively used. .

[0012]

The first object of the present invention is to:
It is an object of the present invention to provide a gold plating solution capable of removing a plating-inhibiting component, particularly copper ions, from a gold plating solution in which impurities are accumulated by using a chelate resin.

A second object is to provide a gold plating solution capable of suppressing adsorption of major components of the gold plating solution, gold salts, conductive salts, complexing agents, crystal modifiers, etc. when treated with a chelate resin. It is to be.

A third object is to provide a gold plating solution capable of recovering the current efficiency, current density, purity of deposited gold and the like of the plating solution by chelating treatment.

The inventors of the present invention treated the gold plating solution to which various impurity metals were added with a chelating resin, and then analyzed the components of the obtained plating solution and performed a plating test. We conducted an analysis to see if the above objective was achieved. As a result, they have found that the object is achieved when the complex formation constant of the complexing agent in the gold plating solution satisfies the condition, and have reached the present invention.

Therefore, the gold plating solution according to the first aspect of the present invention is a gold plating solution containing a gold salt, a conductive salt, a crystal modifier and a complexing agent, and is used for plating. Therefore, the impurity metal accumulated in the gold plating solution can be removed by contact with a chelate resin,
It is characterized by.

In the gold plating solution according to the second aspect of the present invention, in the complexing agent, the complexing constant of the complexing agent and the ion of the impurity metal is a chelate resin and the ion of the impurity metal. Is smaller than the above.

The gold plating solution according to the third aspect of the present invention is characterized in that the chelate resin has an iminodiacetic acid type coordination group.

The gold plating solution according to the fourth aspect of the present invention is characterized in that the impurity metal is copper, iron, nickel, chromium or cobalt.

In the gold plating solution according to the fifth aspect of the present invention, the complexing agent has a complex formation constant (log) with copper ions.
K) is 2 to 13.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION <Gold Plating Solution> The gold plating solution treated with the above chelating resin is used for electronic parts, and contains gold salt, conductive salt, crystal modifier and complexing agent. It is contained as a main component. In addition, various optional components (eg, buffer, pH adjuster, oxidizing agent, reducing agent, suspending agent, surfactant, dispersant, antioxidant, brightening agent, pigment, etc.) are included as necessary. can do.

As the gold salt which is an essential component of gold salt, potassium gold cyanide, potassium gold dihydrate, potassium gold gold chloride, sodium gold gold chloride, potassium potassium dichloride, second gold chloride Gold sodium, potassium gold sulfite, sodium gold sulfite,
Examples are potassium gold thiosulfate, sodium gold thiosulfate and mixtures thereof. Particularly preferred in the present invention are potassium potassium gold cyanide and sodium gold sulfite. The concentration of these gold salts in the plating solution is
Generally, it is in the range of 0.1 g / L to 100 g / L, preferably in the range of 0.2 g / L to 30 g / L.

Conductive salt As the conductive salt, (a) organic carboxylic acids such as adipic acid, benzoic acid, citric acid, malic acid, formic acid, succinic acid, acetic acid, lactic acid, malonic acid, oxalic acid, tartaric acid and salts thereof ( Organic compounds represented by preferably potassium salt),
(B) Inorganic compounds represented by sulfite, nitrite, boric acid, borate, nitrate, phosphoric acid, phosphate, sulfate, hydrochloride and the like can be exemplified. Particularly preferred in the present invention are citric acid, phosphoric acid and their potassium salts. The concentration of these conductive salts in the plating solution is generally in the range of 5 g / L to 500 g / L, preferably 10 g / L to 200 g / L.

Crystal modifier As the crystal modifier, inorganic compounds such as (a) arsenic, lead, thallium and selenium, (b) dipyridyl, alkylbenzene sulfonate, triethylenetetramine, hydrazine sulfate, sulfamic acid and other organic compounds A compound can be illustrated. Particularly preferred in the present invention are thallium and lead. The concentration of these crystal modifiers in the plating solution is generally in the range of 1 mg / L to 10 g / L.

Complexing agent As the complexing agent, (a) inorganic compounds such as potassium cyanide, sodium cyanide, potassium sulfite, sodium sulfite, potassium thiosulfate, sodium thiosulfate, ammonia, iodine and ammonium fluoride, ) Citric acid, potassium citrate, sodium citrate, tartaric acid,
Oxalic acid, mercaptosuccinic acid, mercaptopropionic acid, ascorbic acid, dimercaptosuccinic acid, ethylenediamine tetraacetic acid, nitrilotriacetic acid, hydroxyethylethylenediamine triacetic acid, diethylenetriamine pentaacetic acid,
Carboxylic acids such as triethylenetetramine 6-acetic acid, hydroxymethylimino diacetic acid, propanediamine tetraacetic acid, diaminohydroxypropane tetraacetic acid, (c) ethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenetetramine, piperazine, hydantoin, succinimide, Nitrogen compounds such as triethanolamine, hydroxylamine, phenanthroline, glycine, hydroxyethylglycine, diaminopropane,
(D) A phosphonic acid such as aminotrimethylenephosphonic acid, ethylenediaminetetramethylenephosphonic acid, hexamethylenediaminetetramethylenephosphonic acid, dimethylenetriaminepentamethylenephosphonic acid, hydroxyethylidene-2-phosphonic acid, nitrilotrismethylenephosphonic acid, and (pho ) Thioacetamide, sodium diethyldithiocarbamate, dimercaptopropanol, dimercaptopropanesulfonic acid, sulfosalicylic acid, thioglycolic acid, thiocarbazide, thiosemicarbazide, sulfur compounds such as thiourea and the like can be exemplified. When selecting the complexing agent used for the gold plating, it is necessary to select one having a complex formation constant larger than that of the complexing agent contained in the plating solution.

In the present invention, the complexing agent preferably has a complex formation constant (log K) with copper ions of 2 to 13. Thus, those having a complex formation constant of 2 to 13 have a good action as a complexing agent and a high efficiency of removing impurity metals.

The complex formation constant can be determined by the following formula.

[Equation 1] Here, [MY ^n-1 ] represents the complex concentration, [M ^{+ n} ] represents the metal ion concentration, and [Y ^{- 1} ] represents the complexing agent concentration.

Typical complexing agents are shown below according to the complex formation constants.

Citric acid <Dihydroxyethylglycine <Hexamethylenediaminetetramethylenephosphonic acid <Hydroxyethyliminodiacetic acid <Nitrilotriacetic acid <Hydroxyethylethylenediaminetriacetic acid <Ethylenediaminetetramethylenephosphonic acid
<Ethylenediamine tetraacetic acid <Diethylenetriamine pentaacetic acid <Triethylenetetramine hexaacetic acid The concentration of these complexing agents in the plating solution is generally 0.1 g / L.
To 100 g / L, preferably 1 g / L to 50
The range is g / L.

Preparation of Gold Plating Solution and Use thereof The gold plating solution comprising the above essential components and optional components can be prepared and used according to a conventional method. For example,
A predetermined amount of the above essential components and, if necessary, optional components may be added to clear water (preferably ion-exchanged water) at the same time or separately and stirred to prepare. Such a gold plating solution has a pH of acidic,
It can be adjusted to be neutral or alkaline.

As for the usage conditions of the gold plating solution, that is, the plating conditions, conventional methods can be adopted. For example, the temperature is 30
Current density is 0.01 A / dm ^{2 in} the range of 90 ° C to 90 ° C
To 60 A / dm ² can be used. Regular or continuous replenishment of the gold salt component and necessary components, and pH adjustment and specific gravity adjustment can also be carried out in accordance with ordinary methods.

Such a gold plating solution is used continuously by periodically replenishing the gold salt component and necessary components each time it is used and adjusting the pH of the plating solution. Phenomena in which the current efficiency or the current density range, which had been sufficient, are gradually decreased are observed. at the same time,
The purity of the deposited gold plating layer also decreases, the color tone of the gold plating becomes dark (this phenomenon is called redness), and the problem of insufficient adhesive strength occurs in wire bonding and the like.

This is because impurities eluted from the substrate, especially metal ions, are accumulated in the gold plating solution, and it is required to selectively remove only these interfering components from the gold plating solution. It was

When the chelate resin is used as an adsorbent when the complex formation constant of the complexing agent contained in the gold plating solution is smaller than that of the chelate resin, impurity ions are removed, but the necessary components for plating. Gold salt and crystal modifier are not adsorbed. The gold plating solution satisfying such conditions can be put to practical use again by regenerating it with a chelate resin.

<Chelate Resin> As a specific example of the chelate resin for removing the impurity metal ions accumulated in the gold plating solution by using the above gold plating solution for plating,
(A) resin having iminodiacetic acid type coordination group, (b) resin having polyamine type ligand, (c) resin having amidoxime type ligand, (d) resin having glucamine type ligand, ( E) a resin having an aminophosphoric acid type ligand,
(F) a resin having a dithiocarbamine type ligand, (g)
The resin which has a thiourea type ligand can be mentioned.
Particularly preferable chelate resin in the present invention is the resin having the above-mentioned (i) iminodiacetic acid type coordination group, and among them, particularly, cellulose type, phenol type, acrylic type, epoxy type, poval type, styrene type, divinylbenzene. A resin having a structure in which a base polymer is used as a matrix and aminopolycarboxylic acid is chemically bonded thereto is preferable. The aminopolycarboxylic acid here is ethylenediamine 4
Examples thereof include acetic acid, hydroxyethylethylenediamine triacetic acid, nitrilotriacetic acid, diethylenetriamine pentaacetic acid, triethylenetetramine hexaacetic acid, dicarboxymethylglutamic acid, hydroxyethyliminodiacetic acid, propanediaminetetraacetic acid, and diaminohydroxypropanetetraacetic acid. .

<Contact Treatment of Gold Plating Solution with Chelate Resin> The contact treatment of the chelating resin used and the gold plating solution can be carried out by any purposeful method. For example, a batch method and a continuous method (column method) can be adopted. Specifically, the batch method can be performed by dispersing the chelate resin in the gold plating solution used for plating and then separating the chelate resin from the gold plating solution, and the continuous method is used for the plating method. It can be carried out by extracting a part of the prepared gold plating solution, bringing it into contact with a chelate resin for a regeneration treatment, and then introducing this into the gold plating solution used for the plating. The amount of the chelate resin used can be appropriately determined according to the type of plating, the operating conditions, and the degree of regeneration treatment. In case of batch method, 5g / L to 10 for the plating solution to be regenerated.
Range of 0 g / L, preferably 10 g / L to 50 g / L
The chelating resin in the range of 3 to 300 minutes, preferably 5 to 60 minutes can be contacted. In the case of the continuous method, the space velocity (Space Ve
It can be carried out by passing a liquid at a locity of 1 to 100, preferably 3 to 30.

The shape, shape and size of the chelating resin used during the treatment may be any suitable one. Examples thereof include powder, granules or lumps, aggregates thereof, fibers and cloths. Further, a chelate resin may be attached to a suitable carrier or the like, if necessary.

Furthermore, it is possible to bring the chelate resin into contact with the plating solution by housing the chelate resin in a fibrous bag and immersing the bag in the plating solution.

[0039]

EXAMPLES The following examples describe preferred specific examples of the method for regenerating a gold plating solution according to the present invention.
Therefore, it is needless to say that the present invention is not limited to the scope specifically disclosed in the following examples.

The evaluation tests adopted in the following examples are as follows.

ICP (high frequency inductively coupled plasma) measurement: "ICPS-1000" (manufactured by Shimadzu Corporation) Current efficiency measurement: "galvanostat HA-151"
(Manufactured by Hokuto Denko) ・ Current density range measurement: "Galvanostat HA-15
1 "(manufactured by Hokuto Denko) -X-ray diffraction measurement:" JDX-8030 "(manufactured by JEOL Ltd.)-SEM (scanning electron microscope) measurement:" S-800 "
(Hitachi, Ltd.)-Gold ion concentration measurement: "ICPS-1000" (Shimadzu Corporation) -Copper ion concentration measurement: "ICPS-1000" (Shimadzu Corporation) -Thallium ion concentration measurement: "ICPS-1000""
(Shimadzu Corporation) -Lead ion concentration measurement: "ICPS-1000" (Shimadzu Corporation) <Example 1> A gold plating solution having the following composition was prepared.

Potassium iodopotassium cyanide 8 g / L Potassium citrate (log K = about 2.5) 150 g / L Potassium phosphate 30 g / L Ammonium sulfate 50 g / L Thallium 8 mg / L Using this plating solution, 5 cm square PH of 6.
A running test of gold plating was performed under the conditions of 0, current density of 0.2 A / dm ² , and plating temperature of 65 ° C. The gold salt and the components of the plating solution were replenished every 0.1 turns, and the running for a total of 1.5 turns was completed.

Cellulose-based iminodiacetic acid type chelating resin ("ICP-S", manufactured by CREST) was added to this plating solution.
g / L was added, and the mixture was stirred for 30 minutes and 72 hours at different times, filtered, and subjected to ICP measurement, current efficiency measurement, and X-ray diffraction measurement.

Table 1 shows the analysis results of the metal components of the plating solution before and after the contact treatment with the chelate resin. It can be seen that after the contact treatment with the chelate resin, most of the gold ions and thallium ions remained, but most of the copper ions were removed. Table 2 shows before and after running,
It shows the current efficiency of the plating solution before and after the contact treatment with the chelate resin, and the color tone and crystal orientation of the obtained gold deposit. The current efficiency of the plating solution is 11 by running.
0.9 mg / A. However, the contact treatment with the chelating resin for 72 hours again resulted in 117.3 mg / min.
A. It can be seen that it has returned to min. Also, due to the running, the color tone of the gold plating with reddishness has returned to the original lemon yellow.

[0045]

[Table 1]

[Table 2] <Example 2> A plating solution having the following composition was prepared.

Potassium primary gold cyanide 8 g / L 3 potassium citrate 50 g / L citric acid 40 g / L dipotassium phosphate 50 g / L hydroxyethylimino diacetic acid (log K = about 12) 5 g / L lead 8 ppm This plating solution , PH 6.0, current density 0.3A
A gold plating running test was conducted on a 5 cm square copper substrate under the conditions of / dm ² and a temperature of 60 ° C. Gold salt and the above plating solution components are replenished every 0.1 turn, and the total 1.
After running for 6 turns, 1 L of this plating solution was passed through a column filled with 100 g of a styrene-based iminodiacetic acid type chelate resin (“CR-11” manufactured by Mitsubishi Chemical Corporation) at a space velocity of 50 Velocity. And the filtrate I
After CP analysis and current efficiency measurement, S of gold plating film formed
EM measurement and X-ray diffraction measurement were performed.

Table 3 shows the ICP measurement results. From this table, it can be seen that after the contact treatment with the chelate resin, most of the gold ions and lead ions remained in the filtrate, and the copper ions were removed. Table 4 shows the results of current efficiency, color tone and XD. It can be seen that the current efficiency is restored by the contact treatment with the chelate resin. Further, it can be seen that the crystal orientation of the gold coating is constant even after this regeneration treatment step, and the redness of the gold plating generated by running is restored.

[0048]

[Table 3]

[Table 4] <Example 3> A gold plating solution having the following composition was prepared.

Potassium iodopotassium cyanide 8 g / L Potassium citrate 150 g / L Potassium phosphate 30 g / L Ammonium sulfate 50 g / L Dihydroxyethylglycine (log K = about 8) 5 g / L Thallium 8 mg / L Using this plating solution PH 6. on a 5 cm square copper substrate.
A running test of gold plating was performed under the conditions of 0, current density of 0.2 A / dm ² , and plating temperature of 65 ° C. The gold salt and the components of the plating solution were replenished every 0.1 turns, and the running for a total of 1.5 turns was completed.

Cellulose type iminodiacetic acid type chelating resin 10 g / L (manufactured by CHIREST, "ICP-
S ”) was added, the mixture was stirred for 30 minutes and 72 hours at different times, filtered, and subjected to ICP measurement, current density range measurement, X-ray diffraction measurement and SEM measurement.

Table 5 shows the analysis results of the metal components of the plating solution before and after the contact treatment with the chelate resin. It can be seen that after the contact treatment with the chelate resin, most of the gold ions and thallium ions remain, but most of the copper ions are removed. Table 6 shows the current density range measurement of the plating solution before and after running and before and after the contact treatment with the chelate resin, and the color tone and crystal orientation of the obtained gold deposit.

[0052] usable current density range of the plating solution, running through 0.1A ^/ dm ² -0.9A ^/ dm 2
Reduced to 0.1A ^/ dm ² -0.7A ^/ dm 2 from, but by the contact treatment with the chelating resin, again 0.1A
It can be seen that / dm ² −0.9 A / dm ² is restored. At the same time, the redness caused by running has returned.

[0053]

[Table 5]

[Table 6] <Example 4> A plating solution having the following composition was prepared.

Potassium aluminium cyanide 8 g / L 3 potassium citrate 50 g / L citric acid 40 g / L dipotassium phosphate 50 g / L lead 8 ppm Using this plating solution, pH 6.0 and current density 0.3 A
A gold plating running test was conducted on a 5 cm square copper substrate under the conditions of / dm ² and a temperature of 60 ° C. Gold salt and the above plating solution components are replenished every 0.1 turn, and the total 1.
After running for 6 turns, 1 L of this plating solution was passed through a column filled with 30 g of a styrene-based iminodiacetic acid type chelate resin (“CR-11” manufactured by Mitsubishi Chemical Co., Ltd.) under the condition of a space velocity of 20. And the filtrate is IC
After P analysis and current density range measurement, SEM measurement and X-ray diffraction measurement of the produced gold plating film were performed.

Table 7 shows ICP measurement results. From this table, it can be seen that after the contact treatment with the chelate resin, most of the gold ions and lead ions remained in the filtrate, and the copper ions were removed. Table 8 shows the current density test,
7 shows the results of color tone and XD. It can be seen that the current density range is restored by the contact treatment with the chelate resin. Further, it can be seen that the crystal orientation of the gold coating was constant even after this regeneration treatment step, and the redness was restored.

[0056]

[Table 7]

[Table 8] <Example 5> In the gold plating solution composition of Example 3, ethylenediaminetetraacetic acid was substituted for dihydroxyethylglycine to prepare a gold plating solution having the following composition.

Potassium iodopotassium cyanide 8 g / L Potassium citrate 150 g / L Potassium phosphate 30 g / L Ammonium sulfate 50 g / L Ethylenediaminetetraacetic acid (log K = about 15) 5 g / L Thallium 8 mg / L Using this plating solution PH 6. on a 5 cm square copper substrate.
0, a current density of 0.2 A / dm ² , and a plating temperature of 65 ° C. were subjected to a running test of gold plating. While supplementing gold salt and the above plating solution components every 0.1 turns,
Finished running for 1.5 turns.

Cellulose-based iminodiacetic acid type chelating resin 10 g / L (manufactured by Kirest, "ICP-
S ”) was added, and the mixture was stirred for 30 minutes and 72 hours at different times, filtered, and subjected to ICP measurement, current density range measurement, X-ray diffraction measurement, and color tone measurement. As shown in Tables 9 and 10, the effect of removing copper ions and the effect of improving the used current density are lower than those in Example 3, and the redness is not eliminated.
This is presumably because the chelating constant of the complexing agent in the plating solution was not lower than that of the chelating resin.

[0059]

[Table 9]

[Table 10]

[0060]

INDUSTRIAL APPLICABILITY The gold plating solution according to the present invention is capable of removing the impurity metal accumulated in the gold plating solution when it is used for plating by contact with the chelate resin. Such a gold plating solution according to the present invention can remarkably recover the current efficiency and current density range during plating by contact treatment with a chelate resin, and the gold salt and other essential components of the gold plating solution (ie, Adsorption of conductive salts, complexing agents and crystal modifiers can be suppressed within a range where there is no effect,
In addition, it is possible to deposit a film having a crystal structure which is substantially the same as that obtained from the gold plating solution at the beginning of the bath, from the regenerated plating solution.

[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the concentration of impurity ions accumulated in a gold plating solution and the incidence of defective bonding of deposited gold plating.

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[Procedure amendment]

[Submission date] August 6, 2001 (2001.8.6)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

Complexing agent As the complexing agent, (a) inorganic compounds such as potassium cyanide, sodium cyanide, potassium sulfite, sodium sulfite, potassium thiosulfate, sodium thiosulfate, ammonia, iodine and ammonium fluoride, ) Citric acid, potassium citrate, sodium citrate, tartaric acid,
Oxalic acid, mercaptosuccinic acid, mercaptopropionic acid, ascorbic acid, dimercaptosuccinic acid, ethylenediamine tetraacetic acid, nitrilotriacetic acid, hydroxyethylethylenediamine triacetic acid, diethylenetriamine pentaacetic acid,
Carboxylic acids such as triethylenetetramine 6-acetic acid, hydroxymethylimino diacetic acid, propanediamine tetraacetic acid, diaminohydroxypropane tetraacetic acid, (c) ethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenetetramine, piperazine, hydantoin, succinimide, Nitrogen compounds such as triethanolamine, hydroxylamine, phenanthroline, glycine, hydroxyethylglycine, diaminopropane,
(D) A phosphonic acid such as aminotrimethylenephosphonic acid, ethylenediaminetetramethylenephosphonic acid, hexamethylenediaminetetramethylenephosphonic acid, dimethylenetriaminepentamethylenephosphonic acid, hydroxyethylidene-2-phosphonic acid, nitrilotrismethylenephosphonic acid, and (pho ) Thioacetamide, sodium diethyldithiocarbamate, dimercaptopropanol, dimercaptopropanesulfonic acid, sulfosalicylic acid, thioglycolic acid, thiocarbazide, thiosemicarbazide, sulfur compounds such as thiourea and the like can be exemplified. When selecting the complexing agent used for gold plating, select one that has a complex formation constant with the impurity metal ion smaller than that of the chelate resin and the impurity metal ion. Shall.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazuhiro Okubo             3-10-18 Kitamachi, Nerima-ku, Tokyo Japan High School             Purity Chemical Co., Ltd. (72) Inventor Keizo Kiyohara             3-10-18 Kitamachi, Nerima-ku, Tokyo Japan High School             Purity Chemical Co., Ltd. F-term (reference) 4K023 AA25 BA17 BA22 BA23 BA24                       CA01 CA04 CA08 CA09 CB03                       CB07 CB11 CB13 DA03 DA06                       DA07 DA08                 5E343 BB23 CC78 GG11 GG20

Claims (5)

[Claims] 1. A gold plating solution comprising a gold salt, a conductive salt, a crystal modifier and a complexing agent, wherein an impurity metal accumulated in the gold plating solution when used for plating is used as a chelate resin. A gold plating solution, which can be removed by contact with. 2. The complexing agent is characterized in that the complex constant of the complexing agent with the ion of the impurity metal is smaller than the complex constant of the chelate resin with the ion of the impurity metal. The gold plating solution according to claim 1. 3. The gold plating solution according to claim 1, wherein the chelate resin has an iminodiacetic acid type coordination group. 4. The impurity metal is copper, iron, nickel, chromium or cobalt.
The gold plating solution according to any one of 1 to 3. 5. The gold plating according to any one of claims 1 to 4, wherein the complexing agent has a complex formation constant (log K) with copper ions of 2 to 13. liquid.