JP2024031708A - Measuring apparatus and measuring method for gold concentration in gold-containing plating liquid - Google Patents

Abstract

To provide a gold concentration measuring apparatus and measuring method that accurately and easily analyze the gold concentration in a non-cyanide based gold-containing plating liquid such as a substitution or reduction type gold plating liquid.SOLUTION: When a deterioration state of a non-cyanide based gold-containing plating liquid is detected through absorbance measurement, a specific water-soluble polymer such as polyvinylamines, polyvinyl acetamides and polyvinylformamides is added as a dispersant to the plating liquid including metal ions in combination together with a reductant so as to keep metal particles produced in the plating liquid in a stable colloidal state to a certain time width, and the gold colloid concentration can be accurately and easily analyzed through the absorbance measurement at proper time to stably manage the plating liquid.SELECTED DRAWING: Figure 2

Description

The present invention relates to an apparatus and method for measuring gold concentration in a non-cyanoid gold-containing plating solution, in which colloidal gold particles generated in the gold-containing plating solution are stably held for a certain period of time, and the gold concentration is measured by absorbance measurement. To provide a device that allows concentration to be analyzed accurately, easily, and in a timely manner.

Gold plating liquid is not only chemically stable, but also has electrical and physical properties that make it widely used in the electronics field, including as contacts and wiring materials for electronic components, contributing to the miniaturization and higher functionality of electronic devices. There is.
Traditionally, cyanide-based plating solutions have been commonly used as gold plating solutions due to their high stability and ease of management, but cyanide-based plating solutions are difficult to handle due to toxicity and have negative effects on the environment due to disposal. Due to these problems, non-cyanide gold plating solutions using gold sulfite and the like have been put into practical use.
On the other hand, when focusing on the concentration control of the gold plating solution, the gold concentration can be easily determined by potentiometric titration in the cyan-based plating solution. In addition, in non-cyanide plating solutions, the gold concentration is determined using an analyzer such as ICP or fluorescent X-ray.

However, the above measurement method requires complicated techniques to operate the analyzer, and the number of personnel who can perform measurements is limited. Furthermore, since it takes time to obtain measurement results, there are problems such as not being able to respond immediately to the state of deterioration of the plating solution, so it is not optimal as a control method in the production process.

Therefore, examples of devices or methods for detecting the deterioration state of a gold plating solution include the following prior documents.
(1) Patent document 1
Regarding a mixed solution containing a gold-containing solution, a reducing agent (borohydride compound, dimethylamine borane, hypophosphorous acid, ascorbate, etc.), iodide as a reduction aid, and water, gold ions are removed by the reducing agent. The present invention provides a method and apparatus for quantifying the gold concentration in a gold-containing solution by measuring the absorbance of the reduced gold concentration in a predetermined wavelength range (claims 1 and 6).
In order to measure absorbance in a predetermined wavelength range (for example, 520±10 nm in claim 3) that is not easily affected by deterioration due to repeated use of gold-containing solutions, the gold-containing concentration can be determined with high precision, sensitivity, and efficiency in a short time. ([0010]). In addition, since iodide is used as a reducing agent, it has the effect of accelerating the reducing agent, is useful as a coloring agent, and has the effect of adjusting the absorbance difference between new and aged liquids ([0037] ).

(2) Patent document 2
This is a gold plating solution management device that detects the degree of deterioration of a gold plating solution based on absorbance at wavelengths in the range of 340 to 450 nm (claims), and is a document that is the basis of the absorbance measurement method.
As an example of the wavelength and absorbance characteristics of a gold plating solution, as the degree of plating increases, the absorbance particularly decreases around wavelengths of 340 to 450 nm, and this device utilizes this phenomenon (see upper right of page 2). column).

(3) Patent document 3
An electrolytic gold plating method using a sulfite gold plating solution, in which plating is performed while detecting deterioration of the plating solution (claim 1), and the deterioration detection involves, for example, measuring the intensity of a specific absorption wavelength of the plating solution. sulfite in the gold sulfite complex in the plating solution (Claim 2) or by measuring the pH of the plating solution (Claim 3). (Claim 4) or by measuring sulfuric acid in the plating solution.

(4) Patent document 4
During electrolytic gold plating using a gold sulfite plating solution, a plating apparatus is constructed of a plating treatment tank containing a plating solution, a replenishment means for replenishing the plating solution, and a plating solution analysis means for analyzing the plating solution in the treatment tank or replenishment means. The present invention is characterized in that the deterioration state of the plating solution is evaluated from the absorption characteristics of ultraviolet rays having a wavelength of 220 to 240 nm (claim 1).
According to the above plating apparatus, the deterioration state of the plating solution can be evaluated with high accuracy before gold colloid is generated in the plating solution containing the gold sulfite complex due to a disproportionation reaction ([0009]).

Japanese Patent Application Publication No. 2014-105338 Japanese Patent Application Publication No. 02-110348 Japanese Patent Application Publication No. 2002-030498 Japanese Patent Application Publication No. 2005-113239

In the above-mentioned conventional technology, there is a method of measuring the absorption intensity near 310 nm using spectrophotometry to detect the amount of colloidal gold particles in the plating solution (Patent Document 3), and a method of measuring the absorption intensity in the vicinity of 310 nm (Patent Document 3), A method (Patent Document 4) has been implemented in which the strength is measured and the degree of oxidation of the plating solution is detected.
However, although each detection method can detect the degree of deterioration of the plating solution, it is not possible to quantify the gold concentration in the plating solution. For this reason, it has been impossible to detect state changes other than deterioration, such as changes in gold concentration due to dilution or concentration of the plating bath, making it difficult to maintain stable plating solution management.
The technical problem of the present invention is to directly analyze the concentration of colloidal gold particles by focusing on changes in conditions other than deterioration, specifically, the condition of colloidal gold particles in a plating solution.

Therefore, the present inventors added a specific dispersant to the plating solution together with a reducing agent to control the colloidal gold particles produced in the electroless gold plating solution for a predetermined time. The idea was to maintain the gold concentration stably across the width and measure the gold concentration accurately and easily using the absorbance method.

Invention 1 (A) collects a non-cyanide gold or gold alloy plating solution (gold-containing plating solution),
(B) A gold concentration measuring device that measures the concentration of colloidal gold particles generated from gold ions due to the action of the reducing agent using absorbance in a specific wavelength range for a gold colloid aqueous solution obtained by adding a reducing agent to the collected gold-containing plating solution. ,
(C) Further adding a dispersant to the gold colloid aqueous solution of (B) above,
The above dispersants include polyvinylamines, polyvinylacetamides, polyvinylformamides, polyvinylpyrrolidones (PVPs), polyethyleneimines (PEIs), polyallylamines, polyamines (PAs), and polyvinylimidazoles (PVIs). ), polyacrylamides (PAMs), and polyacrylamides (PAMs).

Present invention 2 is a gold-containing plating solution according to the present invention 1, characterized in that the concentration of the water-soluble polymer (C) in the gold colloid aqueous solution is 0.02 g/L to 40.0 g/L. This is a gold concentration measuring device.

Present invention 3 is the above-mentioned invention 1, wherein the reducing agent (B) comprises a borohydride compound, an amine borane, a hypophosphorous acid, an aldehyde, an ascorbic acid, a hydrazine, a citric acid compound, and a tin chloride. This is an apparatus for measuring gold concentration in a gold-containing plating solution, characterized in that the gold concentration is at least one selected from the group consisting of:

The present invention 4 is a gold-containing plating solution according to the present invention 1 or 3, characterized in that the concentration of the reducing agent (B) in the gold colloid aqueous solution is 0.01 to 1.0 mol/L. This is a gold concentration measuring device.

The present invention 5 is an apparatus for measuring gold concentration in a gold-containing plating solution according to the present invention 1, characterized in that the specific wavelength range of (B) is 300 to 800 nm.

The present invention 6 provides the above-mentioned present invention 1 or 5, wherein: (1) a plating solution tank containing a gold-containing plating solution;
(2) a reaction cell for preparing a gold colloid aqueous solution by mixing a reducing agent and a dispersant with a gold-containing plating solution collected from a plating solution tank;
(3) an absorbance unit that measures the concentration of colloidal gold particles generated in the reaction cell by absorbance in a predetermined wavelength range;
(4) a gold concentration display device that displays the concentration of colloidal gold particles;
(5) A replenishment device that replenishes the gold plating solution of (1) above from the replenishment tank that receives a replenishment signal to the plating solution tank based on the absorbance measured by the absorbance unit of (3) above. This is a device for measuring gold concentration in a gold-containing plating solution.

Present invention 7 includes (a) a step of collecting a non-cyanide gold or gold alloy plating solution (gold-containing plating solution);
(b) Add a reducing agent to a small amount of the collected gold plating solution, and add polyvinylamines, polyvinylacetamides, polyvinylformamides, polyvinylpyrrolidones (PVPs), polyethyleneimines (PEIs), polyallylamines, and polyamines. (PAs), polyvinylimidazoles (PVIs), and polyacrylamides (PAMs). ,
(c) measuring the concentration of colloidal gold particles generated in the aqueous gold colloid solution by the action of the reducing agent by absorbance in a specific wavelength range;
(d) A method for measuring gold concentration in a gold-containing plating solution, comprising the steps of: (d) receiving a replenishment signal based on the measured absorbance and replenishing the gold-containing plating solution.

When detecting the deterioration state of a non-cyanoid gold-containing plating solution by measuring absorbance, a specific water-soluble polymer such as polyvinylamines, polyvinylacetamides, or polyvinylformamides is added to the gold-containing plating solution as a dispersant along with a reducing agent. When added in combination, the gold particles generated in the plating solution can be maintained in a stable colloidal state over a certain period of time, making it possible to accurately, simply, and timely analyze the gold colloid concentration by measuring absorbance.
In addition, the gold colloid concentration can be analyzed accurately and easily without being affected by the deterioration state of the plating solution, and gold ions can be replenished in a timely manner based on the characteristic absorption peak measured by absorbance measurement of the plating solution. , plating solution can be managed stably.

On the other hand, although it is not related to a device for measuring gold concentration in a gold plating solution, there are some prior documents in which the electroless gold plating solution itself is the object of the invention, but they are related to a specific water-soluble polymer that is a feature of the present invention. There is.
First, Prior Document 1 (Japanese Unexamined Patent Publication No. 2010-144220) relates to a displacement gold plating solution for coating protruding electrodes, which contains potassium sulfite and polyethyleneimine or a derivative thereof (see claims 1, 6, and 8). It is described that this polyethyleneimine or its derivative improves the appearance of the gold coating and improves the adhesion of the coating to protrusions ([0017]).
Prior Document 2 (Japanese Unexamined Patent Publication No. 2003-013248) relates to an electroless gold plating solution containing an organic phosphonic acid or a salt thereof and polyethyleneimine (claims 1, 3 to 4). It is described that organic phosphonic acid or its salt stabilizes gold ions in a plating solution as a complexing agent ([0009]), and that polyethyleneimine improves adhesion to the underlying metal film ([0018]). .
Prior Document 3 (Japanese Unexamined Patent Publication No. 08-239768) relates to an electroless gold plating solution and describes that polyethyleneimine can be added as a brightening agent (Claim 9, [0015]).

First, the present invention provides a method for adding a reducing agent to a non-cyanoid gold-containing plating solution and measuring the concentration of the generated colloidal gold particles by absorbance in a specific wavelength range. This is an apparatus for measuring gold concentration in a gold-containing plating solution in which a water-soluble polymer is added. This is a method for measuring the gold concentration of a gold-containing plating solution, which comprises a step of measuring the absorbance of particles and a step of replenishing the gold-containing plating solution based on the absorbance.
The above-mentioned gold-containing plating solution refers to both a gold plating solution and a gold alloy plating solution, and the plating solution is a concept that includes a substitutional or reduction type plating solution, and excludes an electroplating solution.
Furthermore, since the gold-containing plating solution is limited to non-cyanide-based plating solutions (see the first item above), cyan-based gold-containing plating solutions are excluded.
The above gold alloy plating solutions include gold-tin alloy plating solution, gold-palladium alloy plating solution, gold-nickel alloy plating solution, gold-antimony alloy plating solution, gold-copper alloy plating solution, gold-zinc alloy plating solution, gold - Binary alloy plating solutions such as indium alloy plating solution, gold-ruthenium alloy plating solution, and ternary alloy plating solution such as gold-nickel-palladium alloy plating solution.
On the other hand, the water-soluble polymer functions as a dispersant in the gold-containing plating solution and is selected from a specific group of polymers such as polyvinylamines and polyvinylacetamides.

In the present invention 1, (A) a non-cyanide gold-containing plating solution is collected,
(B) A gold concentration measuring device that adds a reducing agent to the collected gold-containing plating solution and measures the concentration of colloidal gold particles generated from gold ions in the aqueous gold colloid solution by absorbance in a specific wavelength range,
(C) This is an apparatus for measuring gold concentration in a gold-containing plating solution, in which the gold colloid aqueous solution of (B) above further contains a specific dispersant selected from polyvinylamines, polyvinylacetamides, etc.
As mentioned above, the non-cyanide gold-containing plating solution (A) above is a general concept of the gold plating solution and the gold alloy plating solution, and below, the gold plating solution will be explained first, and then the gold alloy plating solution Explain briefly.

The above gold plating solution can be classified into a displacement gold plating solution and a reduced type gold plating solution. For example, a displacement gold plating solution contains gold ions, a base acid or salt, various additives, etc. as a plating composition.
First, the gold plating solution must contain a soluble gold salt for supplying the gold ions.
As the above-mentioned soluble gold salt, any soluble salt that generates gold ions in an aqueous solution can be used, and there are no particular restrictions, and hardly soluble salts are not excluded. Specifically, they include sodium gold sulfite, sodium chloraurate, sodium gold thiosulfate, or potassium salts and ammonium salts thereof.

Further, the displacement gold plating solution can contain various additives such as a base acid or salt, a stabilizer, a pH adjuster, and a surfactant.
Base acids or salts thereof include sodium, potassium, and ammonium salts of sulfite, sodium, potassium, and ammonium salts of thiosulfate, and the like.
The above-mentioned stabilizers have the function of stabilizing gold ions in the liquid, and include oxidants such as citric acid, tartaric acid, malic acid, gluconic acid, glucoheptonic acid, glycolic acid, lactic acid, trioxybutyric acid, or their sodium and potassium salts. Carboxylic acids, ethylenediaminetetraacetic acid (EDTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA), triethylenetetraminehexaacetic acid (TTHA), ethylenediaminetetrapropionic acid, nitrilotriacetic acid (NTA), iminodiacetic acid ( IDA), iminodipropionic acid (IDP), or aminocarboxylic acids such as their sodium salts and potassium salts, ethylenediaminetetramethylene phosphate, diethylenetriaminepentamethylene phosphate, aminotrimethylene phosphate, pentasodium aminotrimethylene phosphate Examples include aminophosphoric acids such as salts, ethanolamines such as triethanolamine, and ascorbic acids.

Examples of the pH adjuster include various acids such as hydrochloric acid, sulfuric acid, oxalic acid, boric acids, and phosphoric acids, and various bases such as potassium hydroxide, sodium hydroxide, ammonia, and amines, and preferably weak acids. The pH is adjusted to a range of from to neutral.
The above-mentioned surfactants include various conventional surfactants such as nonionic, anionic, amphoteric, and cationic surfactants, which contribute to improving the denseness, smoothness, adhesion, etc. of the plating film.
Examples of the anionic surfactants include alkyl sulfates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkylphenyl ether sulfates, alkylbenzene sulfonates, alkylnaphthalene sulfonates, and the like. Examples of the cationic surfactant include mono- to trialkylamine salts, dimethyldialkyl ammonium salts, trimethylalkylammonium salts, and the like.
Examples of the nonionic surfactants include C ₁ to C ₂₀ alkanols, phenols, naphthols, bisphenols, C ₁ to C ₂₅ alkylphenols, arylalkylphenols, C ₁ to C ₂₅ alkylnaphthols, and C ₁ to C ₂₅ alkoxyl phosphoric acids ( salts), sorbitan esters, polyalkylene glycols, C ₁ -C ₂₂ aliphatic amides, etc., with addition condensation of 2 to 300 moles of ethylene oxide (EO) and/or propylene oxide (PO).
Examples of the amphoteric surfactant include carboxybetaine, imidazoline betaine, sulfobetaine, aminocarboxylic acid, and the like.
As for specific examples of displacement gold plating solutions, as shown in [0057] of Patent Document 1 above, a gold-containing solution containing gold ions contains a complexing agent such as sodium sulfite and a pH buffering agent such as citric acid. Examples include compositions that

As shown in (B) above of Invention 1, a reducing agent and a dispersing agent are added together to the collected gold plating solution, and the concentration of gold colloidal particles generated from gold ions in the gold plating solution is reduced by the action of the reducing agent. , measured by absorbance in a specific wavelength range.
In the above (B), the reducing agent and the dispersing agent may be added to the gold plating solution at the same time, or the reducing agent and the dispersing agent may be added with a time difference.
As shown in Invention 3 above, the reducing agent is a borohydride compound (sodium or potassium borohydride, etc.), amine borane (dimethylamine borane, etc.), or hypophosphorous acid (sodium hypophosphite, etc.). , aldehydes (formaldehyde, etc.), ascorbic acids (sodium L-ascorbate, etc.), hydrazines (hydrazine hydrate, monomethylhydrazine, etc.), citric acid compounds, stannous (II) chloride, etc., and these can be used alone. Or can be used together.

The present invention 1 is characterized in that, as shown in (C) above, a dispersant made of a specific water-soluble polymer is added to the gold plating solution.
The dispersant suppresses aggregation of the gold colloid and maintains the colloidal state.
The above specific water-soluble polymers include polyvinylamines, polyvinylacetamides, polyvinylformamides, polyvinylpyrrolidones (PVPs), polyethyleneimines (PEIs), polyallylamines, polyamines (PAs), and polyvinylimidazoles. (PVIs) and polyacrylamides (PAMs), and these can be used alone or in combination.
Preferred examples of the water-soluble polymer include polyvinylamines, polyvinylacetamides, polyvinylformamides, PVPs, PEIs, polyallylamines, and PAs.

In the above (B) of the present invention 1, an appropriate amount of the gold plating solution is taken, and a reducing agent and a dispersant are added thereto in combination to prepare a gold colloid aqueous solution.
In this case, the content of soluble gold salt (gold ion) in the gold colloid aqueous solution is generally 0.002 to 0.08 g/L, preferably 0.005 to 0.05 g/L, more preferably 0.01 to 0. It is .03g/L.
Similarly, in the gold colloid aqueous solution, the content of the reducing agent is generally 0.01 to 1.0 mol/L, preferably 0.02 to 0.5 mol/L, more preferably 0.04 to 0.3 mol. /L.
Similarly, the content of water-soluble polymer is generally 0.02 to 40.0 g/L, preferably 0.2 to 30.0 g/L, and more preferably 1.0 to 20.0 g/L.
The reaction temperature is generally 10 to 40°C, preferably 15 to 35°C, more preferably 20 to 30°C.
The reaction time is generally 60 minutes or less, preferably 30 minutes or less, more preferably 15 minutes or less.

In the first aspect of the invention, as shown in item (B), the concentration of colloidal gold particles generated from gold ions by the action of a reducing agent is measured by absorbance in a specific wavelength range.
The specific wavelength range is generally 300 to 800 nm, preferably 500±100 nm, and more preferably 500±20 nm.
As shown in Item (C) of Invention 1, since a reducing agent and a dispersant are added together to the gold plating solution, the gold ions are reduced to gold particles by the reducing agent, and the gold particles become colloids due to the action of the dispersant. Although the state is maintained for a predetermined time width, in the absorbance measurement described above, the produced gold colloid particles show an absorption peak in the absorbance region of 300 to 800 nm (see FIGS. 1 to 5 below).

In the above, the case where a gold colloid aqueous solution is prepared by adding a reducing agent and a dispersant together on the premise of a displacement gold plating solution has been explained. However, when the gold plating solution is a reduced type plating solution, the above [0024] As shown at the end, as described in [0058] of Patent Document 1, a gold-containing aqueous solution containing gold ions, a complexing agent such as sodium sulfite, a reducing agent such as ascorbic acid, and 2-amino-4- Compositions containing stabilizers such as methylbenzothiazole may be mentioned.
For example, when gold plating is performed on a base metal such as nickel or gold using a reduced gold plating solution, the base metal has a catalytic action, so the precipitation reaction occurs only on the base metal and its vicinity; Gold ions remain as ions without being reduced.
In the present invention, colloidal particles of gold are generated by adding a reducing agent and a specific dispersant to the gold ions, and the gold concentration can be smoothly measured by absorbance measurement.

As mentioned above, the gold-containing plating solution of the present invention 1 is a non-cyanide gold plating solution or a gold alloy plating solution. Binary alloys such as tin alloy, gold-palladium alloy, gold-nickel alloy, gold-antimony alloy, gold-copper alloy, gold-zinc alloy, gold-indium alloy, gold-ruthenium alloy, or gold-nickel-palladium These include ternary alloys such as alloys.
The amount of reducing agent and dispersant added, the preparation method of the gold alloy plating solution, the reaction temperature, the reaction time, etc. are the same as in the case of the above-mentioned gold plating solution. Furthermore, the procedure for measuring absorbance is not particularly different from that for gold plating solution.

Below, the outline of the apparatus for measuring the gold concentration in a gold colloid aqueous solution of the present invention will be explained, as well as the composition of the displacement type gold plating solution for preparing the gold colloid aqueous solution, and the adjustment method when analyzing the gold concentration of the gold colloid aqueous solution. In addition, Examples and Comparative Examples listing measurement methods, and analytical evaluations based on absorption spectra of these Examples will be sequentially explained.
It should be noted that the present invention is not limited to the following embodiments and the like, and it goes without saying that arbitrary modifications can be made within the scope of the technical idea of the present invention.

《Schematic explanation of the gold concentration measuring device in gold colloid aqueous solution》
FIG. 6 is a schematic diagram of an apparatus for measuring gold concentration in an aqueous gold colloid solution.
First, a gold plating liquid tank 1 contains a displacement type gold plating liquid. This displacement type gold plating solution contains gold ions (soluble gold salts), base salts, stabilizers, etc., but does not contain a reducing agent. The gold plating solution is supplied from the tank 1 to the reaction cell 2 described below, and a reducing agent and a dispersing agent are separately added thereto.
In the reaction cell 2, a plating solution containing gold ions supplied from the plating solution tank 1, a reducing agent, a dispersant (water-soluble polymer), and pure water supplied from another solution tank are respectively supplied. The gold ions are supplied and merged, and the gold ions are reduced to gold colloid particles by the action of a reducing agent and a dispersant, thereby producing a gold colloid aqueous solution. The gold colloid aqueous solution is stably maintained in a colloidal state over a certain period of time (specifically, for about 30 minutes).
Next, the reaction solution containing the gold colloid particles produced in the reaction cell 2 is sent to the absorbance unit 3, and the absorbance in the reaction solution is measured. The absorbance unit 3 consists of a light source, a light receiving section, an absorbance cell, etc., and constitutes an absorbance measurement mechanism.
Then, the gold concentration is displayed on the display device 6 linked to the absorbance unit 3, and the amount of replenishment according to the degree of deterioration of the plating solution is calculated in the control device 4, which is also linked to the absorbance unit 3. A replenishment liquid (the above-mentioned gold plating liquid excluding the reducing agent and water-soluble polymer) is supplied to the plating liquid tank 1 from the replenishment liquid tank 5 which has received a replenishment signal indicating the amount of the plating liquid components.
Incidentally, the reaction cell 2, the absorbance unit 3, the gold concentration display device 6, and the control device 4 for calculating the amount of replenishment constitute a gold concentration analyzer for a gold colloid aqueous solution.
Further, this analyzer, replenishment liquid tank 5, and plating liquid tank 1 are integrated to constitute the entire gold concentration measuring apparatus.
Incidentally, the gold colloid aqueous solution after the measurement is drained from the reaction cell 2 and the absorbance unit 3.

《Composition of displacement type gold plating solution》
As mentioned above, the composition of the displacement type gold plating solution stored in the plating solution tank 1 is as follows.
Sodium gold sulfite (as Au ion) 1g/L
Sodium sulfite 50g/L
Sodium gluconate 25g/L
Ethylenediaminetetraacetic acid disodium 25g/L
Sodium/potassium tartrate 10g/L
pH 7
In the above plating solution composition, sodium sulfite is a base salt of the plating solution, and sodium gluconate, ethylenediaminetetraacetate, and tartrate are gold ion stabilizers.

Example 1 below lists the overall composition of an aqueous gold colloid solution obtained by adding a reducing agent and a water-soluble polymer to the gold plating solution, as well as a method for preparing and measuring the aqueous gold colloid solution.
Examples 2 to 5 are examples in which the type of dispersant was changed based on the above Example 1. Example 6 is an example in which the amount of the dispersant added was changed based on Example 1 above. Example 7 is an example in which the type of reducing agent was changed based on the above Example 1. Example 8 is an example in which the amount of the reducing agent added was changed based on the above Example 1.
On the other hand, Comparative Example 1 is an example in which the dispersant of the present invention is omitted based on the above Example 1, and Comparative Example 2 is an example based on the above Example 1, but with a water-soluble polymer that does not belong to the specific dispersant of the present invention 1. This is an example in which .

《Example 1》
The gold plating solution supplied from the plating solution tank 1 joins with the reducing agent, the dispersant of the present invention 1, and pure water in the reaction cell 2, where the entire gold colloid aqueous solution (i.e., analysis solution) is formed. , and subjected to absorbance analysis. The method for preparing and measuring the analytical solution is as follows.
(1) Composition of gold colloid aqueous solution Gold plating solution 1mL
Polyvinylamine (concentration 100g/L) 10mL
Dimethylamine borane (concentration 50g/L) 15mL
(2) Method for preparing analytical solution As mentioned above, 1 mL of gold plating solution was added to a 50 mL beaker containing about 10 mL of ion-exchanged water, and then 10 mL of polyvinylamine (concentration 100 g/L) and dimethylamine borane ( 15 mL of each solution (concentration 50 g/L) were added, and ion-exchanged water was further added to adjust the volume to 50 mL.
The temperature at the time of adjustment was 25° C., and the samples were left for 10 minutes, 20 minutes, and 30 minutes.
(3) Method for measuring analytical solution Absorbance was measured in the wavelength range of 300 to 800 nm using a spectrophotometer (HITACHI U-2910 optical path length: 10 mm quartz cell).

《Example 2》
(1) Composition of gold colloid aqueous solution Gold plating solution 1mL
Polyvinylacetamide (concentration 100g/L) 10mL
Dimethylamine borane (concentration 50g/L) 15mL
(2) Method for preparing analysis solution: Add 1 mL of gold plating solution to a 50 mL beaker containing about 10 mL of ion exchange water, then add 10 mL of polyvinylamine (concentration 100 g/L) and dimethylamine borane (concentration 50 g/L). 15 mL of each were added, and ion-exchanged water was further added to adjust the volume to 50 mL. The temperature at the time of adjustment was 25°C, and the mixture was left for 10 minutes.
(3) Method for measuring analysis liquid Measurement was performed in the same manner as in Example 1.

《Example 3》
(1) Composition of gold colloid aqueous solution Gold plating solution 1mL
Polyvinylformamide (concentration 100g/L) 10mL
Dimethylamine borane (concentration 50g/L) 15mL
(2) Method for preparing analysis liquid Analytical solution was prepared in the same manner as in Example 2.
(3) Method for measuring analysis liquid Measurement was performed in the same manner as in Example 1.

《Example 4》
(1) Composition of gold colloid aqueous solution Gold plating solution 1mL
Polyallylamine (concentration 100g/L) 10mL
Dimethylamine borane (concentration 50g/L) 15mL
(2) Method for preparing analysis liquid Analytical solution was prepared in the same manner as in Example 2.
(3) Method for measuring analysis liquid Measurement was performed in the same manner as in Example 1.

《Example 5》
(1) Composition of gold colloid aqueous solution Gold plating solution 1mL
Polyethyleneimine (concentration 100g/L) 10mL
Dimethylamine borane (concentration 50g/L) 15mL
(2) Method for preparing analysis liquid Analytical solution was prepared in the same manner as in Example 2.
(3) Method for measuring analysis liquid Measurement was performed in the same manner as in Example 1.

《Example 6》
(1) Composition of gold colloid aqueous solution Gold plating solution 1mL
Polyvinylamine (concentration 100g/L 0.5-10mL
Dimethylamine borane (concentration 50g/L) 15mL
(2) Method for preparing analysis liquid Analytical solution was prepared in the same manner as in Example 2.
The amount of the polyvinylamine (dispersant) added was changed to 0.5 mL, 3 mL, 5 mL, 7 mL, and 10 mL, respectively.
(3) Method for measuring analysis liquid Measurement was performed in the same manner as in Example 1.

《Example 7》
(1) Composition of gold colloid aqueous solution Gold plating solution 1mL
Polyvinylamine (concentration 100g/L) 10mL
Sodium borohydride (concentration 50g/L) 10mL
(2) Method for preparing analysis liquid Analytical solution was prepared in the same manner as in Example 2.
(3) Method for measuring analysis liquid Measurement was performed in the same manner as in Example 1.

《Example 8》
(1) Composition of gold colloid aqueous solution Gold plating solution 1mL
Polyvinylamine (concentration 100g/L) 10mL
Dimethylamine borane (concentration 50g/L) 2-20mL
(2) Method for preparing analysis liquid Analytical solution was prepared in the same manner as in Example 2.
(3) Method for measuring analysis liquid Measurement was performed in the same manner as in Example 1.

《Comparative example 1》
(1) Composition of gold colloid aqueous solution This is an example in which the specific dispersant defined in Invention 1 is not used.
Gold plating solution 1mL
Dimethylamine borane (concentration 50g/L) 10mL
(2) Method for preparing analysis liquid Analytical solution was prepared in the same manner as in Example 2.
(3) Method for measuring analysis liquid Measurement was performed in the same manner as in Example 1.

《Comparative example 2》
(1) Composition of gold colloid aqueous solution This is an example using a water-soluble polymer that does not fall within the specific dispersants specified in Invention 1.
Gold plating solution 1mL
Polyethylene glycol (concentration 100g/L) 10mL
Dimethylamine borane (concentration 50g/L) 15mL
(2) Method for preparing analysis liquid Analytical solution was prepared in the same manner as in Example 2.
(3) Method for measuring analysis liquid Measurement was performed in the same manner as in Example 1.

《Analysis evaluation using absorption spectrum》
(a) Regarding FIG. 1 This is an absorption spectrum of the gold colloid aqueous solution of the displacement gold plating solution of Example 1 at standing times of 10 minutes, 20 minutes, and 30 minutes.
Looking at the absorption characteristics of the plating solution, it can be seen that the absorption intensity changes greatly at a wavelength of around 500 nm for each standing time, forming a peak.
As time passes after the gold particles in the plating solution form a colloid, the colloidal state collapses, the gold particle size increases, and the peak disappears. However, in Example 1, even after 30 minutes had elapsed, It can be seen that the gold particles stably maintain a colloidal state.

(b) Regarding FIG. 2 This is an absorption spectrum of the gold colloid aqueous solution when the type of dispersant was changed for each of the displacement gold plating solutions of Examples 1 to 5 and Comparative Examples 1 and 2.
Again, it can be seen that the absorption intensity changes greatly around the wavelength of 500 nm. Looking at the absorption spectrum for each dispersant, the absorbance peaks are large in Examples 4 and 1, and small in Examples 2, 3, and 5, but the stability of colloidal gold particles can be measured by the presence or absence of peaks. The strength of the peak does not affect the stability of the colloidal gold particles.
Therefore, in terms of the function of the dispersant (specific water-soluble polymer) specified in the present invention to maintain the gold particles in the plating solution in a colloidal state, there is no difference in effectiveness even if the type of dispersant is changed. It can be concluded that there is no such thing.
On the other hand, in both Comparative Example 1 and Comparative Example 2, no peak appears in the absorption spectra, confirming that the colloidal state cannot be maintained once the gold ions are reduced to gold by administering the reducing agent to the gold plating solution. It will be done.
Therefore, when comparing the water-soluble polymer (polyethylene glycol) of Comparative Example 2 to a specific polymer of the present invention (e.g., polyvinylamine of Example 1), the present invention shows that the water-soluble polymer (polyethylene glycol) of Comparative Example 2 is superior in its ability to stably maintain gold particles in a colloidal state. The advantages of certain water-soluble polymers are clear.

(c) Regarding Figure 3 Regarding Example 6, the absorbance is shown when the amount of dispersant (polyvinylamine) added is changed in five steps from 0.5 to 10 ml, but all have similar values at a wavelength of around 500 nm. It can be seen that a peak is formed.
Therefore, it can be determined that even when a very small amount (for example, 0.5 mL) of the dispersant is added, the gold particles in the plating solution can be well maintained in a colloidal state for 10 minutes.

(d) Regarding FIG. 4 Examples 1 and 7 show absorption spectra when both dispersants were immobilized on polyvinylamine and the type of reducing agent was changed. When the type of reducing agent was changed, the size of the absorption peak at a wavelength of around 500 nm varied, but there was no difference in the appearance of the peak itself.
Therefore, it is assumed that the effectiveness of the dispersant specified in the present invention in maintaining the gold particles in the plating solution in a colloidal state over a certain period of time remains the same even if the type of reducing agent is changed. I can judge.

(e) Regarding Figure 5 In Example 8, the absorption spectra were shown when polyvinylamine was used as the dispersant and the amount of reducing agent (dimethylamine borane) added was changed. Regardless, it can be seen that a similar peak is formed at a wavelength of around 500 nm.
Therefore, it can be determined that under the conditions in which the dispersant of the present invention coexists with the reducing agent, the gold particles in the plating solution can be well maintained in a colloidal state for 10 minutes even when a very small amount of the reducing agent is added.

(f) Conclusion Taking Figures 1 to 5 together, when a reducing agent is added to a gold plating solution, a dispersant selected from a specific water-soluble polymer is further added, and the absorbance analysis is performed, due to the action of the dispersant, Gold particles in the plating solution can be stably maintained in a colloidal state within a certain time range (for example, about 30 minutes), and can be used in non-cyanide-based gold-containing plating solutions such as displacement gold plating solution and reduction gold plating solution. Gold concentration can be analyzed accurately, easily and in a timely manner.
In addition, when analyzing the gold-containing plating solution of the present invention, a reducing agent and a specific dispersant are added together, so when measuring the absorbance of the plating solution, the components of the plating solution are determined based on the characteristic absorption peak at a predetermined wavelength. By replenishing the plating solution, you can maintain a stable plating solution.

3 is an absorption spectrum of a gold colloid aqueous solution obtained in Example 1 with different standing times. These are absorption spectra of gold colloid aqueous solutions obtained in Examples 1 to 5 and Comparative Examples 1 to 2 using different types of dispersants (However, Comparative Example 1 did not contain any dispersant). 3 shows absorption spectra of gold colloid aqueous solutions obtained in Example 6 with different amounts of dispersant added. 2 is an absorption spectrum of gold colloid aqueous solutions obtained in Examples 1 and 7 using different types of reducing agents. 3 shows absorption spectra of gold colloid aqueous solutions obtained in Example 8 with different amounts of reducing agent added. FIG. 2 is a schematic system diagram of a gold concentration measuring device in a displacement gold plating solution.

DESCRIPTION OF SYMBOLS 1... Gold plating liquid tank, 2... Reaction cell, 3... Absorbance cell, 4... Control device, 5... Replenishment liquid tank, 6... Display device.

Invention 1 (A) collects a non-cyanide gold or gold alloy plating solution (gold-containing plating solution),
(B) A gold concentration measuring device that measures the concentration of colloidal gold particles generated from gold ions due to the action of the reducing agent using absorbance in a specific wavelength range for a gold colloid aqueous solution obtained by adding a reducing agent to the collected gold-containing plating solution. ,
(C) Further adding a dispersant to the gold colloid aqueous solution of (B) above,
The above dispersants include polyvinylamines, polyvinylacetamides, polyvinylformamides, polyethyleneimines (PEIs), polyallylamines, polyamines (PAs), polyvinylimidazoles (PVIs), and polyacrylamides (PAMs). ) A gold concentration measuring device in a gold-containing plating solution is characterized in that the gold concentration in a gold-containing plating solution is at least one type of water-soluble polymer selected from the group consisting of:

Present invention 7 includes (a) a step of collecting a non-cyanide gold or gold alloy plating solution (gold-containing plating solution);
(b) Add a reducing agent to a small amount of the collected gold plating solution, and add polyvinylamines, polyvinylacetamides, polyvinylformamides, polyethyleneimines (PEIs) , polyallylamines, polyamines (PAs), and polyvinylimidazoles. (PVIs), polyacrylamides (PAMs), and a step of preparing an aqueous gold colloid solution by adding a dispersant that is at least one type of water-soluble polymer selected from the group consisting of polyacrylamides (PAMs);
(c) measuring the concentration of colloidal gold particles generated in the aqueous gold colloid solution by the action of the reducing agent by absorbance in a specific wavelength range;
(d) A method for measuring gold concentration in a gold-containing plating solution, comprising the steps of: (d) receiving a replenishment signal based on the measured absorbance and replenishing the gold-containing plating solution.

First, the present invention provides a method for adding a reducing agent to a non-cyanoid gold-containing plating solution and measuring the concentration of the generated colloidal gold particles by absorbance in a specific wavelength range. This is an apparatus for measuring gold concentration in a gold-containing plating solution to which a polymer is added (see invention 1 above) . A method for measuring the gold concentration of the gold-containing plating solution, which comprises a step of measuring the absorbance of colloidal gold particles generated in the solution, and a step of replenishing the gold-containing plating solution based on the absorbance (see invention 7 above). .
The above-mentioned gold-containing plating solution refers to both a gold plating solution and a gold alloy plating solution, and the plating solution is a concept that includes a substitutional or reduction type plating solution, and excludes an electroplating solution.
Furthermore, since the gold-containing plating solution is limited to non-cyanide-based plating solutions (see the first item above), cyan-based gold-containing plating solutions are excluded.
The above gold alloy plating solutions include gold-tin alloy plating solution, gold-palladium alloy plating solution, gold-nickel alloy plating solution, gold-antimony alloy plating solution, gold-copper alloy plating solution, gold-zinc alloy plating solution, gold - Binary alloy plating solutions such as indium alloy plating solution, gold-ruthenium alloy plating solution, and ternary alloy plating solution such as gold-nickel-palladium alloy plating solution.
On the other hand, the water-soluble polymer functions as a dispersant in the gold-containing plating solution and is selected from a specific group of polymers such as polyvinylamines and polyvinylacetamides.

The present invention 1 is characterized in that, as shown in (C) above, a dispersant made of a specific water-soluble polymer is added to the gold plating solution.
The dispersant suppresses aggregation of the gold colloid and maintains the colloidal state.
The above specific water-soluble polymers include polyvinylamines, polyvinylacetamides, polyvinylformamides, polyethyleneimines (PEIs), polyallylamines, polyamines (PAs), polyvinylimidazoles (PVIs), and polyacrylamides. (PAMs), and these can be used alone or in combination.
Preferred examples of the water-soluble polymer include polyvinylamines, polyvinylacetamides, polyvinylformamides, PEIs , polyallylamines, and PAs.

《Schematic explanation of gold concentration measuring device in gold colloid aqueous solution》
FIG. 6 specifically shows the seventh aspect of the present invention, and is a schematic diagram of an apparatus for measuring gold concentration in an aqueous gold colloid solution.
First, a gold plating liquid tank 1 contains a displacement type gold plating liquid. This displacement type gold plating solution contains gold ions (soluble gold salt), a base salt, a stabilizer, etc., but does not contain a reducing agent. The gold plating solution is fed from the tank 1 to the reaction cell 2 described below, and a reducing agent and a dispersing agent are separately added thereto.
In the reaction cell 2, a plating solution containing gold ions supplied from the plating solution tank 1, a reducing agent, a dispersant (water-soluble polymer), and pure water supplied from another solution tank are respectively supplied. The gold ions are supplied and merged, and the gold ions are reduced to gold colloid particles by the action of a reducing agent and a dispersant, thereby producing a gold colloid aqueous solution. The colloidal gold aqueous solution is stably maintained in a colloidal state over a certain period of time (specifically, for about 30 minutes).
Next, the reaction solution containing the gold colloid particles produced in the reaction cell 2 is sent to the absorbance unit 3, and the absorbance in the reaction solution is measured. The absorbance unit 3 includes a light source, a light receiving section, an absorbance cell, etc., and constitutes an absorbance measuring mechanism.
Then, the gold concentration is displayed on the display device 6 linked to the absorbance unit 3, and the control device 4 also linked to the absorbance unit 3 calculates the amount of replenishment according to the degree of deterioration of the plating solution, and calculates the amount to be replenished according to the degree of deterioration of the plating solution. A replenishment liquid (the above gold plating liquid excluding the reducing agent and water-soluble polymer) is supplied to the plating liquid tank 1 from the replenishment liquid tank 5 which has received a replenishment signal indicating the amount of the plating liquid components.
Incidentally, the reaction cell 2, the absorbance unit 3, the gold concentration display device 6, and the control device 4 for calculating the amount of replenishment constitute a gold concentration analyzer for an aqueous gold colloid solution.
Further, this analyzer, replenishment liquid tank 5, and plating liquid tank 1 are integrated to constitute the entire gold concentration measuring device.
Incidentally, the gold colloid aqueous solution after the measurement is drained from the reaction cell 2 and the absorbance unit 3.

Claims (7)

(A) Collect non-cyanide gold or gold alloy plating solution (gold-containing plating solution),
(B) A gold concentration measuring device that measures the concentration of colloidal gold particles generated from gold ions due to the action of the reducing agent using absorbance in a specific wavelength range for a gold colloid aqueous solution obtained by adding a reducing agent to the collected gold-containing plating solution. ,
(C) Further adding a dispersant to the gold colloid aqueous solution of (B) above,
The above dispersants include polyvinylamines, polyvinylacetamides, polyvinylformamides, polyvinylpyrrolidones (PVPs), polyethyleneimines (PEIs), polyallylamines, polyamines (PAs), and polyvinylimidazoles (PVIs). ), polyacrylamides (PAMs), and polyacrylamides (PAMs). Measurement of gold concentration in a gold-containing plating solution according to claim 1, wherein the concentration of the water-soluble polymer (C) in the aqueous gold colloid solution is 0.02 g/L to 40.0 g/L. Device. The reducing agent in (B) above is at least one selected from the group consisting of boron hydride compounds, amineboranes, hypophosphorous acids, aldehydes, ascorbic acids, hydrazines, citric acid compounds, and tin chloride. The apparatus for measuring gold concentration in a gold-containing plating solution according to claim 1. Measurement of gold concentration in a gold-containing plating solution according to claim 1 or 3, wherein the concentration of the reducing agent (B) in the aqueous gold colloid solution is 0.01 to 1.0 mol/L. Device. The apparatus for measuring gold concentration in a gold-containing plating solution according to claim 1, wherein the specific wavelength range of (B) is 300 to 800 nm. (1) A plating solution tank containing a gold-containing plating solution,
(2) a reaction cell for preparing a gold colloid aqueous solution by mixing a reducing agent and a dispersant with a gold-containing plating solution collected from a plating solution tank;
(3) an absorbance unit that measures the concentration of colloidal gold particles generated in the reaction cell by absorbance in a predetermined wavelength range;
(4) a gold concentration display device that displays the concentration of colloidal gold particles;
(5) It shall consist of a replenishment device that replenishes the gold-containing plating solution in (1) above from the replenishment tank that receives a replenishment signal to the plating solution tank based on the absorbance measured by the absorbance unit in (3) above. The apparatus for measuring gold concentration in a gold-containing plating solution according to claim 1 or 5. (a) A step of collecting a non-cyanide gold or gold alloy plating solution (gold-containing plating solution);
(b) A reducing agent is added to the collected gold-containing plating solution, and polyvinylamines, polyvinylacetamides, polyvinylformamides, polyvinylpyrrolidones (PVPs), polyethyleneimines (PEIs), polyallylamines, and polyamines are added. (PAs), polyvinylimidazoles (PVIs), and polyacrylamides (PAMs). ,
(c) measuring the concentration of colloidal gold particles generated in the aqueous gold colloid solution by the action of the reducing agent by absorbance in a specific wavelength range;
(d) A method for measuring gold concentration in a gold-containing plating solution, comprising the steps of: (d) receiving a replenishment signal based on the measured absorbance and replenishing the gold-containing plating solution.

Images