JP2742128B2 - Method for adjusting plating solution concentration and plating method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for adjusting the component concentration of a plating solution and a plating method.

[Prior Art] Generally, gold plating is extremely important in the production of wiring boards because it has excellent solderability, connectivity such as wire bonding, etching resistance, rust prevention, and electrical conductivity. Technology.

As a gold plating solution used for electroless plating, a cyan plating solution is usually used because of excellent stability of the plating solution. However, since the cyan plating solution has problems in pollution control, in recent years, gold ions as metal components, thiosulfate ions and sulfite ions as ligands forming complexes with gold ions, and thiourea as a reducing agent have been recently developed. And a non-cyanide electroless gold plating solution containing:

When plating is performed using the above-described non-cyanide-based plating solution, the change over time in the component concentration and the plating rate are as follows:
This will be described with reference to FIGS. 6 and 7.

FIG. 6 shows a change in component concentration when plating is performed without adding a component constituting the plating solution as a replenisher. On the other hand, FIG. 7 shows the change in the component concentration and the plating rate when the component decreasing as the plating progresses is added as a replenisher and the concentration of the plating solution component is kept constant.

FIG. 6 shows the component concentration on the vertical axis and the plating time on the horizontal axis.

As is clear from FIG. 6, as the plating proceeds, the concentrations of sulfite ions and thiosulfate ions do not change, but the concentrations of gold ions and thiourea decrease. For this reason, the plating rate gradually decreases.

FIG. 7 also shows the component concentration on the vertical axis and the plating time on the horizontal axis. Further, changes in the plating rate with the passage of the plating time are also shown.

As shown in FIG. 7, by measuring the consumption of gold and thiourea with the progress of plating at regular time intervals, and supplementing the consumed amount, it is possible to maintain the plating speed within a certain range for a long time. Can be.

As described above, in electroless plating, both the metal component and the reducing agent component of the plating solution components are consumed as plating proceeds. In addition, since the electroless plating rate greatly depends on the concentration of the plating solution components, in order to maintain a constant plating rate, the concentrations of both the metal component and the reducing agent component are measured, and the consumed amount is sequentially determined. Need to refill.

Here, the concentration of each component is measured, for example, using an atomic absorption spectrophotometer for a metal component, using a sodium nitroprusside method for thiourea as a reducing agent, and using an ion chromatography method for a sulfite ion and a thiosulfate ion. Can be done.

[Problems to be Solved by the Invention] However, in the method for quantitatively analyzing the components of the non-cyanide plating solution, it is necessary to dilute the sample solution each time because the atomic absorption method has high sensitivity. Analyze that sodium nitroprusside is easily decomposed. For this reason, the measurement takes time and is used for analysis at a laboratory level, but is not suitable for analysis of a manufacturing process.

Further, as for the measurement of the concentration of the metal component in the electroless plating solution, as proposed in Japanese Patent Application Laid-Open No. 63-121668, a method of measuring the concentration of a metal ion by an absorption spectrophotometry, Alternatively, as described in JP-A-60-164239, a method using X-ray fluorescence analysis,
As described in JP-A-62-14053, there is a method utilizing potentiometric titration and the like.

As for the concentration measurement of the reducing agent component such as formalin in the electroless plating solution, as described in JP-A-53-9235, there is a method of measuring from the amount of current required for oxidation of the reducing agent. .

However, among the above-mentioned prior arts, the method using coloration of a metal component and the method using potentiometric titration have a problem that the types of applicable electroless plating solutions are limited and the versatility is poor.

On the other hand, regarding the method of measuring the concentration of the reducing agent component, no consideration is given to an electroless plating solution containing a large amount of a reducing ion such as a sulfite ion or a thiosulfate ion as a complexing agent in addition to the reducing agent.

For example, when measuring the concentration of the reducing agent from the amount of current required for the oxidation of the reducing agent, the sulfite ion and the thiosulfate ion are also oxidized at the same time, so that the component concentration of the reducing agent cannot be measured accurately. .

As described above, conventionally, in the plating technology, particularly in the electroless plating technology, there is no technology capable of accurately measuring the component concentration of the plating solution in the manufacturing process, and therefore, there is a problem that the component concentration cannot be appropriately controlled. Was.

The present invention uses a plating solution component concentration adjusting method for controlling the component concentration of a non-cyanide electroless gold plating solution within a certain range, and uses a plating solution whose component concentration is controlled within a certain range by the method. An object of the present invention is to provide a plating method.

[Means for Solving the Problems] An object of the present invention is a method for measuring a component concentration of a plating solution containing a metal component, an anion and a reducing agent, wherein the anion interferes with the concentration measurement of the reducing agent. This is achieved by a method for measuring the concentration of a component in a plating solution, wherein the concentration of the reducing agent is measured after substituting with another anionic species that does not give the following.

A method for measuring a component concentration of a plating solution containing a metal component, an anion, and a reducing agent, wherein the anion is replaced with another anion species that does not disturb the measurement of the concentration of the reducing agent, and then the reduction is performed. It is achieved by a component concentration measuring method of a plating solution, which comprises measuring the concentration of an agent and further measuring the concentration of the metal component by an atomic absorption method or a plasma emission analysis method.

Preferably, the concentration of the reducing agent is measured by an ultraviolet absorption detection method or an electrochemical quantification method.

A method for measuring a component concentration of a plating solution comprising a metal component, a reducing ion, and a non-ionic reducing agent, wherein after replacing the reducing ion with a non-reducing ion, the concentration of the non-ionic reducing agent The present invention is also achieved by a method for measuring the concentration of a component in a plating solution, which comprises measuring and measuring the concentration of the metal component.

Measurement of metal component concentration in plating solution and calibration of metal component concentration measuring means used for this measurement, measurement of reducing agent concentration in plating solution and calibration of reducing agent concentration measuring means used for this measurement, The operation of replacing the anion with another anion species that does not disturb the concentration measurement of the reducing agent is performed by sequence control according to a preset sequence program, and further, the measured value obtained by the measurement and the measurement value The present invention is also achieved by a method for measuring a component concentration of a plating solution, wherein a metal component concentration and a reducing agent concentration in a plating solution are obtained by calculation from a calibration value obtained by calibration.

A method for adjusting the concentration of a plating solution containing a metal component, an anion and a reducing agent, wherein the anion in the plating solution is replaced with another anion species that does not disturb the concentration measurement of the reducing agent, and then the metal is removed. Calibration of metal component concentration measuring means for measuring components and calibration of reducing agent concentration measuring means for measuring the reducing agent component, measurement of metal component concentration by the metal component concentration measuring means, and reducing agent by the reducing agent concentration measuring means Based on the calibration value and the measured value obtained from the measurement of the concentration, the consumption of the metal component and the reducing agent component is obtained by calculation, and further, a replenisher containing the reducing agent and the metal component corresponding to the consumption is plated with a plating solution. It can also be achieved by a method of adjusting the concentration of a plating solution characterized by replenishing the plating solution.

The concentration adjusting method of the present invention is a device for adjusting the component concentration of a plating solution containing a metal component, an anion and a reducing agent,
An anion exchange means for replacing the anion with an anion species which does not interfere with the measurement of the concentration of the reducing agent; a regeneration means for regenerating the ion exchange means using a solution containing the anion species; and Reducing agent concentration measuring means for measuring, metal component concentration measuring means for measuring the metal component concentration, calibration of the reducing agent concentration measuring means and the metal component concentration measuring means, reducing agent concentration measuring means and the metal Sequence control means for controlling the measurement of the plating solution component by the component concentration measuring means, and further, from the measured value obtained by the measurement and the calibration value obtained by the calibration, the concentration of the metal component in the plating solution and reduction The present invention can be applied to an apparatus for measuring the concentration of a component in a plating solution, which has a calculation control means for calculating the concentration of the agent.

The concentration adjusting method of the present invention is a device for adjusting the component concentration of a plating solution containing a metal component, an anion and a reducing agent,
An anion exchange means for replacing the anion with an anion species which does not interfere with the measurement of the concentration of the reducing agent; a regeneration means for regenerating the ion exchange means using a solution containing the anion species; and Reducing agent concentration measuring means for measuring, metal component concentration measuring means for measuring the metal component concentration, sequence controlling means for controlling operations of the reducing agent concentration measuring means and the metal component concentration measuring means, Calculating means for calculating the consumption of the reducing agent and the metal component from the difference between the measured values of the agent concentration and the metal component concentration, and the respective set concentrations; and the reducing agent and the metal component corresponding to the consumption. The present invention can be applied to an apparatus for adjusting the concentration of a component of a plating solution, comprising: an arithmetic control unit having a supply unit for supplying a replenisher to a plating tank.

Further, the plating method of the present invention is a plating apparatus for performing plating using a plating solution containing a metal component, an anion and a reducing agent, wherein the plating device comprises a plating tank, a plating solution concentration measuring means, and a plating solution replenisher. Means, sequence control means and arithmetic control means,
The plating solution concentration measuring means is an ion exchange means for replacing the anion with another anion species which does not disturb the concentration measurement of the reducing agent, a reducing agent concentration measuring means for measuring the reducing agent concentration, and the metal component Metal concentration measuring means for measuring the concentration, the sequence control means controls the operation of the plating solution concentration measuring means, the arithmetic control means, the measured value of the reducing agent concentration and the metal component concentration, respectively Calculating means for calculating the consumption of the reducing agent and the metal component from the difference between the set concentration and the replenisher containing the reducing agent and the metal component corresponding to the consumption, and supplying the plating solution from the plating solution replenisher to the plating tank. The present invention can be applied to a plating apparatus having a supply unit.

Further, the concentration adjusting method of the present invention comprises: a metal component concentration measuring means for measuring the concentration of a metal component contained in a solution; and a non-metal component concentration measuring means for measuring a non-metal component concentration. A control function for measuring the operation of the component concentration measuring means and the non-metal component concentration measuring means; a measured value of the concentration of the metal component and the concentration of the non-metal component; The present invention can be applied to a concentration management device having a supply function of supplying a replenisher containing a metal component and a replenisher containing a non-metal component corresponding to the consumption of a metal component.

The metal component concentration measuring means is preferably an atomic absorption spectrophotometer or a plasma emission spectrophotometer.

More preferably, the non-metal concentration measuring means has an anion exchanger and an ultraviolet absorption detector or an electrochemical quantification device.

[Operation] The anion exchange material in the anion exchanger is regenerated to a chloride ion type using a regenerating solution, for example, a KCl (potassium chloride) solution, and a certain amount of the electroless plating solution sample is poured into the regenerating solution. In this case, since the sulfite ion and thiosulfate ion in the plating solution, the complex ion coordinated to the metal ion, and the like, and the affinity for the anion exchange substance are larger than the chloride ion, the It is trapped and an equivalent amount of chloride ions elutes instead.

On the other hand, reducing agents such as thiourea and formalin contained in the electroless plating solution are not trapped by the anion exchange material because they are nonionic, and elute from the anion exchanger as they are.

Thus, the reducing ions contained in the plating solution can be removed.

When the reducing agent contained in the plating solution is a substance exhibiting ultraviolet absorption such as thiourea, the concentration of thiourea can be measured by an ultraviolet absorption detector provided after the anion exchanger. When the reducing agent is a substance that does not exhibit ultraviolet absorption, for example, formalin, the concentration can be calculated from the amount of current required for the oxidation of formalin.

As the anion exchange substance, an anion exchange resin column, an anion exchange membrane or the like can be used. As a regenerating solution for the anion exchange substance, other salts of chloride ions, that is, NaCl and NH ₄ Cl solutions can be used in addition to the KCl solution. In addition to chloride ions, a solution of an anion having a small affinity for an anion exchange substance, such as NaHCO ₃ or
It is also possible to regenerate and use the HCO ₃ ^- type using a KHCO ₃ solution.

On the other hand, the concentration of the metal component contained in the plating solution is measured by an atomic absorption spectrophotometer.

According to the above-described measuring method, the concentrations of the metal ions and the reducing agent, whose concentrations decrease as the plating proceeds, can be measured.

The arithmetic and control means calculates the replenishment amount by obtaining the consumption of the components accompanying the progress of the plating from the difference between the measured concentration of the plating solution and the preset management concentration of the plating solution. Then, by sequentially replenishing the consumption amount from the replenisher tank in accordance with the information on the amount of the consumable component, the component concentration of the plating solution is always managed within a certain range. As a result, the plating speed can be kept constant.

Examples Examples of the present invention will be described below in more detail with reference to the drawings. Note that the present invention is not limited to this.

Example 1 FIG. 1 is a diagram showing an example of an apparatus used for measuring the concentration of thiourea in an electroless plating solution containing KAuCl ₄ , Na ₂ SO ₃ , Na ₂ S ₂ O ₃ and thiourea as main components. FIG.

In the concentration measurement of this embodiment, as shown in FIG. 1, a water tank 1 for storing water (H ₂ O) as a carrier liquid and a regenerating liquid are used.
Regeneration tank 2 for storing 0.2N-KCl solution, metering pumps 3, 4,
6-way valve 5, sampling loop 6, sample inlet
36, an anion exchanger 7, an anion exchange membrane tube 8, an ultraviolet absorption detector 9, and a recorder 37.

The anion exchanger 7 is a double tube having an anion exchange membrane tube 8 inside. The anion exchange membrane tube 8 is supplied at a flow rate of 2 ml / min using a metering pump 4 at a flow rate of 0.2 N.
The regenerating solution of -KCl is sent from the regenerating solution tank 2 to the outer cylinder portion of the anion exchange membrane tube 8, and is constantly regenerated to the chloride ion type. The carrier liquid (H ₂ O) is constantly sent from the water tank 1 to the ultraviolet absorption detector 9 from inside the anion exchange membrane tube 8 at a flow rate of 2 ml / min.

When the plating solution sample diluted 50 times is injected from the sample injection port 36 while the hexagonal valve 5 is in the connection state of the solid line shown in FIG. 1, a certain amount of the plating solution sample is collected in the sampling loop 6. You.

Next, when the six-way valve 5 is switched to be connected to a dotted line state shown in the figure, the carrier liquid (H ₂ O) flows in the sampling loop 6 and the plating solution sample collected in the sampling loop 6 is shaded. It is carried from the ion exchange membrane tube 8 to the ultraviolet absorption detector 9.

Gold complex ions such as sulfite ion, thiosulfate ion and [Au (S ₂ O ₃ ) ₂ ] ^3- in the plating solution sample are captured on the anion exchange membrane, and chloride ion is eluted instead. It is sent to the ultraviolet absorption detector 9 by the carrier liquid. Since thiourea, which is a reducing agent, is a nonionic substance, it is carried to the ultraviolet absorption detector 9 without being captured in the anion exchange membrane tube 8.

The measurement wavelength of the ultraviolet absorption detector 9 is set to 240 nm. Using this ultraviolet absorption detector 9, the thiourea concentration in the plating solution can be measured based on the principle described below.

That is, as is apparent from the absorption curve shown in FIG. 2, the ultraviolet absorption of thiourea shows a maximum absorption at 235 nm, whereas chlorine ions eluted by ion exchange of sulfite ions, thiosulfate ions, etc. Shows no absorption.

In addition, thiourea is oxidized with the progress of plating to generate urea, and this urea does not show ultraviolet absorption as shown in FIG.

Therefore, if the wavelength of the ultraviolet absorption detector 9 is set to 235 to 240 nm, the absorbance of only thiourea in the plating solution can be measured.

The thiourea concentration in the plating solution can be calculated by measuring the absorbance using the thiourea standard solution at the set concentration in the same manner as described above, and calculating the proportionality based on the measured absorbance.

In addition to the method using the anion exchange membrane tube 8, the anion exchanger 7 is composed of two layers of flat anion exchange membranes, a plating solution sample for measuring the concentration inside, and a regenerating solution outside the plating solution. It may have a structure in which a KCl solution is passed.

Example 2 FIG. 3 shows a configuration of an example of a component concentration adjusting device applied to an electroless plating solution device.

In this example, KAuCl ₄ , Na ₂ SO ₃ , Na ₂ S
The component concentration of the electroless plating solution mainly composed of ₂ O ₃ , thiourea and the like is adjusted.

As shown in FIG. 3, the component concentration adjusting device of this embodiment includes a water tank 1 for storing water as a carrier liquid, a regenerating liquid tank 2 for storing a 0.2 N-KCl solution as a regenerating liquid, a metering pump 3,
4. It has a six-way valve 5, a sampling loop 6, an anion exchanger 7, an anion exchange membrane tube 8, and an ultraviolet absorption detector 9. These have substantially the same configuration as the reducing agent concentration measuring apparatus shown in FIG.

The component concentration adjusting apparatus of the present embodiment further includes an atomic absorption spectrophotometer 35 as a means for measuring the gold component concentration of the plating solution, and an arithmetic control unit 10 described later.

The component concentration adjusting apparatus of the present embodiment is provided with a water tank 1, a gold replenisher tank 14, and a thiourea replenisher tank 15 as means for adjusting the concentration of the plating solution in the plating tank 13. Further, a gold standard liquid tank 11 and a thiourea standard liquid tank 12 for storing a calibration liquid used for calibrating the ultraviolet absorption detector 9 and the atomic absorption photometer 35 are provided.

Each of the above tanks, an ultraviolet absorption detector 9 and an atomic absorption spectrophotometer
A piping system connecting 35 is a metering pump 3, 4, 25 to 27, 33, a six-way valve 5 having a sampling loop 6, a six-way valve 28 having a sampling loop 29, and a solenoid valve 16 to 22.
, Manifolds 23 and 24, and a dilution tank 30.

 Hereinafter, the piping system of the present embodiment will be described.

The water tank 1 is connected to the solenoid valve 16, and the gold standard solution tank 11 is connected to the solenoid valve 17.
The thiourea standard solution tank 12 is connected to a solenoid valve 18, and the plating tank 13 is connected to a solenoid valve 19. The solenoid valves 16 to 19 are connected to the suction side of the metering pump 25 via the manifold 23. The discharge side of the metering pump 25 is a six-way valve
By switching 28, the pipe is connected to the sample loop 29 of the six-way valve 28 or the external discharge port.

One port of the six-way valve 28 is connected to the discharge side of the metering pump 27. The discharge side of metering pump 27 is a six-way valve
By switching 28, the pipe is connected to the sample loop 29 of the six-way valve 28 or the dilution tank 30.
The water tank 1 is connected to the suction side of the metering pump 27.

The dilution tank 30 is connected to an atomic absorption photometer 35 having an autosampler 34. Further, the dilution tank 30 is provided with a solenoid valve 31.
The measurement liquid connected to the nitrogen tank 32 and sent to the dilution tank can be stirred in a nitrogen stream.

The dilution tank 30 is connected to the suction side of the metering pump 33. The discharge side of the metering pump 33 is connected to one port of the six-way valve 5. The discharge side of the metering pump 33 is connected to the sample loop 6 of the six-way valve 5 or the external discharge port by switching the six-way valve 5.

Another port of the six-way valve 5 is connected to the discharge side of the metering pump 3. The discharge side of the metering pump 3 is connected to the sample loop 6 of the six-way valve 5 or the anion exchanger 7 by switching the six-way valve 5. A water tank 1 is provided on the suction side of the metering pump 3.
Is connected.

The regenerating liquid tank 2 is connected to the suction side of the metering pump 4, and the discharge side of the metering pump 4 is connected to the anion exchanger 7.

The gold replenisher tank 14 is connected to the solenoid valve 20, and the thiourea replenisher tank
25 is connected to the solenoid valve 21, and the water tank 1 is connected to the solenoid valve 22. The solenoid valves 20 to 22 are connected to the suction side of the metering pump 26 via the manifold 24. And the metering pump 26
The plating tank 13 is disposed on the discharge side of the plating tank 13. That is, each solution stored in the gold replenisher tank 14 and the thiourea replenisher tank 15 is connected to the plating tank 13 by the metering pump 26 so as to be supplied to the plating tank 13.

The arithmetic and control unit 10 includes on / off control of the metering pumps 3, 4, 25 to 27 and 33, opening and closing control of the solenoid valves 16 to 22 and 31, switching control of the six-way valves 5, 28, the ultraviolet absorption detector 9 and the atomic Calculation operations such as collection of a data signal from the absorptiometer 35, calculation of concentration, calculation of the amount of replenisher to be replenished, and the like are performed.

Further, the arithmetic and control unit 10 supplies a required amount of the replenisher to the plating tank 13 from the gold replenisher tank 14 and the thiourea replenisher tank 15, and adjusts the component concentration of the plating solution to a set range.

Although not shown, the arithmetic and control unit includes, for example, a central processing unit (CPU), a memory for storing an operation program of the CPU, operation data and the like, an output device for visually displaying operation results, data, control signals, and the like. I / O for input / output processing,
It comprises an interface, an input device for giving instructions and evaluations from outside, and the like.

Next, the operation of each part when adjusting the concentration of the plating solution component in the plating tank 13 will be described.

First, in response to a command from the arithmetic and control unit 10, the electromagnetic valve 19 is opened, the metering pump 25 is driven, and a part of the plating plate is collected from the plating tank 13 into the sampling loop 29 of the hexagonal valve 28. The metering pump 27 is driven for a certain time and the dilution tank
A certain amount of H ₂ O (water) is fed into 30, and the plating solution sample collected in the sampling loop 29 is simultaneously sent to the dilution tank 30 by switching the six-way valve 28 on the way.

Then open the solenoid valve 31 and briefly dilute the nitrogen gas
The plating solution is agitated by flowing into the dilution tank 30 to dilute the plating solution in the dilution tank 30 at a predetermined magnification. A part of the diluted plating solution sample is sent to an atomic absorption spectrophotometer 35 by an autosampler 34, and the gold concentration in the plating solution is measured.

On the other hand, by driving the metering pump 33, a part of the diluted plating solution sample is collected in the sampling loop 6 of the six-way valve 5, and thereafter, the same method as the method in the reducing agent concentration measuring device shown in FIG. Is used to measure the concentration of thiourea in the plating solution.

The switching of these six-way valves, the driving of the metering pump, and the like are performed by automatic control using the arithmetic and control unit 10.

The calibration of the atomic absorption photometer 35 and the ultraviolet absorption detector 9 is as follows.
The gold standard solution stored in the gold standard solution tank 11 and the thiourea standard solution stored in the thiourea standard solution tank 12 are adjusted to the same concentration as the control (set) concentration of gold and thiourea in the plating solution. And
The operation is performed at least once a day in the same manner as in the measurement of the component concentration of the plating solution.

The calibration value obtained using the standard solution is stored in the arithmetic and control unit 10, and the gold and thiourea concentrations in the plating solution are calculated by a proportional calculation with the calibration value. Then, the replenishment amounts are calculated.

Then, using the metering pump 26, the replenisher is replenished from the gold replenisher bath 14 and the thiourea replenisher bath 15 to the plating bath 13 by the calculated replenishment amount.

That is, the concentrations of gold and thiourea, the concentrations of replenishers of gold and thiourea, the volume of the plating tank 13,
The required amount of replenisher can be replenished by calculating the replenishment time of gold and thiourea based on the flow rate of the metering pump 26 and opening the solenoid valves 20 and 21 sequentially for a predetermined time.

After replenishment of gold and thiourea, the solenoid valve 22
Open and wash the piping system with water.

Embodiment 3 FIG. 4 shows an embodiment using a density control device different from that of FIG.

In this embodiment, as in the embodiment shown in FIG. 3, an atomic absorption spectrophotometer and an ultraviolet absorption detector are used as measuring devices. In this embodiment, a pH electrode is newly provided, and The calibration method of the absorptiometer and the piping system are different.

Na ₂ S ₂ O ₃ , which contains KAuCl ₄ as a gold component and has reducing properties
An example of controlling the concentration of the electroless plating solution containing Na ₂ SO ₃ and thiourea will be described.

The concentration control device of the present embodiment includes an atomic absorption spectrophotometer 102 for measuring the concentration of gold components in the plating solution, and an ion for non-reducing ion exchange of reducing anions such as sulfite ions and thiosulfate ions. An anion exchanger 202 equipped with an exchange membrane tube 201, an ultraviolet absorption detector 203 for measuring the concentration of thiourea, which acts as a reducing agent in the plating solution,
A sequencer 501 having an electrode 302 and a pH meter 303, a control function for calibrating each measuring device and measuring the concentration of the plating solution component, and a calculation function for calculating the consumption of the plating solution component and supply of the consumed component And a calculation control means 401 having a supply control function for controlling the

The arithmetic and control unit 401 has substantially the same configuration as the arithmetic and control unit 10 described in the second embodiment.

The sequencer 501 includes a memory that stores a program control procedure set in advance as a program, and a CPU that sequentially controls the operations of the solenoid valve, the metering pump, the six-way valve, and the like according to the program stored in the memory. Is done.

The sequencer 501 operates according to an instruction from the arithmetic and control unit 401.

In FIG. 4, a solid line is a piping system, and a broken line is a signal transmission path. The transmission path of the sequencer 501 is not shown.

Further, the concentration control device of this embodiment is an atomic absorption spectrophotometer.
Metal component standard solution tank 610 used for the standard solution for calibrating 102
A reducing agent additive solution tank 618, a reducing agent standard solution tank 611 for storing a standard solution for calibrating the ultraviolet absorption detector 203, and a pH electrode 302.
PH buffer solution tank 612 storing a standard solution for calibrating, metal component replenishment solution tank 614 for replenishing metal ions consumed by plating, and reducing agent replenishment solution tank 615 for replenishing the reducing agent consumed by plating, pH adjusting solution replenisher tank 6 for adjusting pH
With 16.

The regenerating solution for supplying anions flowing to the anion exchanger 202 is stored in the regenerating solution tank 619. Further, water used for cleaning the pipe and diluting the sample solution is stored in the water tank 617.

As the replenisher replenished to the plating tanks 61 to 65 by the instruction of the arithmetic control means 401, the liquid stored in the metal component replenisher tank 614, the reducing agent replenisher tank 615, and the pH adjusting liquid replenisher tank 616 is used. You.

The plating tanks 61 to 65 shown in FIG. 4 may be incorporated in the apparatus of this embodiment, or may be connected by a piping system from outside the apparatus. Further, the number of plating tanks is not limited to five.

Each of the measuring devices and each of the solution tanks are connected by a piping system, and each piping system is provided with a solenoid valve, a manifold, a three-way valve, a six-way valve, and a metering pump according to the purpose.

Each of the plating tanks 61 to 65 has an electromagnetic valve 626
~ 630 are connected. One side of the solenoid valve 625 is connected to the water tank 617. The other of solenoid valves 626 to 630 is manifold 64
It is connected to one of the three-way valves 650 through one.

The metal component standard liquid tank 610, a reducing agent standard liquid tank 611,
Electromagnetic valves 621 to 624 are connected to one of the pH buffer solution tank 612 and a Na ₂ S ₂ O ₃ solution tank 613 described later. One side of the solenoid valve 620 is connected to the water tank 617. Solenoid valve 620-6
The other of the 24 is connected to one of the three-way valves 650 via a manifold 640.

The other side of the three-way valve 650 is connected to the suction side of a sampling pump 651 for sampling, and the discharge side of the metering pump 651 for sampling is connected to one port of a six-way valve 660 having a sample loop 661. doing. Another port of the six-way valve 660 is connected to a flow cell 301 into which a pH electrode 302 is inserted. A pH electrode 302 is inserted into the flow cell 301, and the pH measured there is displayed on a pH meter 303.

The metering pump 652, whose suction side is connected to the water tank 617, has its discharge side connected to the dilution tank 670 via a six-way valve 660. In the dilution tank 670, a solenoid valve is provided from a nitrogen gas cylinder 680.
Nitrogen gas is sent in via 681. The solenoid valve 671 is used when the solution in the dilution tank 670 is discarded.

The suction side of the metering pump 656 is connected to the dilution tank 670 through a six-way valve 664 having a sample loop 665 and a diluting sample collection pipe passing through a six-way valve 666 having a sample loop 667.

The suction side of the metering pump 654 is connected to a reducing agent addition liquid tank 618 via a six-way valve 662 having a sample loop 663. The suction side of the metering pump 665 is connected to the water tank 617, and the discharge side of the metering pump 655 is connected to the six-way valves 662 and 664.
Is connected to the dilution tank 672 via a.

From the dilution tank 672, the measurement sample is sent to the atomic absorption spectrophotometer 102 by the autosampler 101. Nitrogen gas is sent into the dilution tank 672 via an electromagnetic valve 682. Solenoid valve 673
Is a solenoid valve for solution disposal.

The suction side of the metering pump 657 is connected to the water tank 617.
Then, from the discharge side of the metering pump 657, the six-way valve 666
From the ion exchange membrane tube 201 through the ultraviolet absorption detector 2
To 03, the carrier liquid (H ₂ O) is sent at a constant speed. The metering pump 658 sends the regenerating solution from the regenerating solution tank 619 to the outer cylinder of the ion exchanger 202.

The metal component replenisher tank 614 is connected via a solenoid valve 636, and the reducing agent replenisher tank 615 is connected via a solenoid valve 637.
616 is connected to the manifold 643 via the solenoid valve 638, and the water tank 617 is connected to the manifold 643 via the solenoid valve 639. And, the manifold 643 is connected to the suction side of the replenishing fixed quantity pump 653. The discharge side of the replenishing fixed quantity pump 653 is connected to one of the solenoid valves 631 to 635 via the manifold 642, and each solenoid valve is connected to the plating tanks 61 to 65.

Calibration of pH meter, calibration of atomic absorption spectrophotometer 102, calibration of ultraviolet absorption detector 203, measurement of plating solution pH, measurement of reducing agent component concentration of plating solution and measurement of gold component concentration of plating solution Is performed by the sequencer 501 in accordance with a command from the arithmetic control means 401.

That is, solenoid valves 620-630,671,673,681,682, metering pumps 651,652,654-658, three-way valve 650, six-way valve 66
0, 662, 664, and 666 are sequentially activated by a command from the sequencer 501.

The calibration method of the measuring device and the method for measuring the concentration of the plating solution component will be described with reference to FIG. In FIG.
The operation enclosed by the double frame is performed by the arithmetic and control unit 401, and the others are performed by the sequencer 501.

 Calibration of the pH meter is performed as follows.

A flow path to be fed into the flow cell 301 is formed through the solenoid valve 623, the three-way valve 650, and the six-way valve 660, and the metering pump 651 is driven to drive the sodium borate buffer solution (pH about 9.2) contained in the buffer solution tank 612. ) Is poured into the flow cell 301. The metering pump 651 is stopped after driving for a certain period of time, and the pH of the pH buffer solution is measured using the pH electrode 302 inserted into the flow cell 301.

After the pH measurement, the electromagnetic valve 620 is opened, and the metering pump 651 is driven to wash the pH electrode cell and the like.

The arithmetic control means 401 stores in advance a permissible range of fluctuation of the calibration values obtained by repeated preliminary experiments, and performs an abnormal value test of the obtained calibration values.

The permissible range is set to an appropriate range by calculating the range of variation of the calibration value in advance through repeated preliminary experiments.

Calibration of pH meter and UV absorption detector 20 described later
3 calibration, atomic absorption photometer 102 calibration, plating solution component concentration measurement, pH meter 303, pH electrode 302, atomic absorption photometer
102, Improper ultraviolet absorption detector 203, reduced ion exchange capacity of ion exchanger, abnormalities of each metering pump, liquid leaks in each piping system, generation of air bubbles in the piping, etc. Affects concentration measurements of liquid components.

When the calibration value deviates from an allowable range described later, the operator is notified by an alarm, and a confirmation is made as to whether to perform the measurement again or to terminate the measurement. In this way, erroneous management based on erroneous measured values is prevented.

The calibration of the ultraviolet absorption spectrophotometer 203 is performed as follows.

After the reducing agent standard solution stored in the reducing agent standard solution tank 611 is taken into the sample loop 661 by the metering pump 651,
By driving the metering pump 652 for a certain period of time,
After that, a certain amount of water is fed into the dilution tank 670. The six-way valve 660 is switched on the way, and the reducing agent standard solution in the sample loop 661 is simultaneously sent to the dilution tank 670, and the reducing agent standard solution is diluted in the dilution tank 670, for example, by 50 times. Further, the metering pump 656 is driven to collect the diluted standard solution in the sample loop 667.

The diluted standard solution passes through an ion-exchange membrane tube 201, and an ultraviolet absorption detector 2 whose measurement wavelength is set to 240 nm.
Measured at 03.

The measurement is performed by sampling the reducing agent standard solution diluted 50 times twice.

The arithmetic control means 401 calculates an average value of two measurements,
Perform an outlier test.

The abnormal value test is performed on both the average value and the variance (absolute value of the difference) of the values measured twice. If any one of the average value and the variation deviates from the previously input allowable range, the operator is notified by an alarm, and confirmation is made as to whether to perform the measurement again or to terminate the measurement.

For this reason, the permissible range is set in advance to an appropriate range through repeated preliminary experiments so that abnormalities in these devices can be found immediately.

Calibration of the atomic absorption photometer 102 is performed as follows.

The standard solution is a mixture of a metal component standard solution obtained by removing thiourea as a reducing agent from the plating solution used in the present embodiment and a reducing agent addition solution composed of a thiourea solution.

The gold standard solution stored in the metal component standard solution tank 610 is diluted with the dilution tank 6
Within 70, in the same way as the preparation of the standard solution for the UV absorption detector,
For example, dilute 50 times.

The metering pump 656 is driven to collect the diluted standard solution into the sample loop 665. At this time, the metering pump 65
Drive 4 to place the reducing agent additive liquid tank in the sample loop 663.
Take thiourea solution from 618. And metering pump 6
55 is driven for a certain time, and in the middle thereof, the six-way valve 664 and the six-way valve 662 are simultaneously switched, and the thiourea solution in the sample loop 663 and the dilution standard solution in the sample loop 665 are simultaneously sent to the dilution tank 672, The mixed solution in the dilution tank 672 is
For example, dilute 100 times.

The standard solution is based on the thiourea added solution concentration and the sample loop 663.
And adjust the composition ratio to be close to the composition ratio of the plating solution management concentration.

The standard solution obtained by the above method was
After being collected by 1, it is measured by the atomic absorption spectrophotometer 102. Again, the standard solution in the dilution tank 672 is sampled and measured.

After the measurement, the solenoid valves 671 and 673 are opened to discard the diluted sample, H ₂ O is sent by the metering pumps 652 and 655, and the dilution tank 670 and 672
Is washed. Further, the electromagnetic valve 620 is opened to drive the metering pump 651, and the piping system for collecting the standard solution is washed.

The arithmetic control means 401 calculates an average value of two measurements,
An abnormal value test is performed in the same manner as the above-described abnormal test of the ultraviolet absorption detector.

When an abnormal value is measured, an alarm device sounds and informs the operator of the abnormality, and it is confirmed whether to perform the measurement again or to terminate the measurement.

pH meter 303, atomic absorption spectrophotometer 102, ultraviolet absorption detector 20
For the third, calibration should be performed at least once a day.

The measurement of the component concentration of the plating solution and the calculation of the correction amount will be described.

 The pH of the plating solution is measured as follows.

For example, a plating solution is supplied from the plating tank 61, and a metering pump 651 is driven, so that a solenoid valve 626, a three-way valve 650, and a six-way valve 660 are provided.
Is sent to the flow cell 301. After stopping the metering pump 651, the pH of the plating solution in the flow cell 301 is measured by the pH electrode 302. After that, the piping system is cleaned.

The concentration of the reducing agent component in the plating solution is measured as follows.

For example, a plating solution is poured from the plating tank 61 into the sample loop 661 of the six-way valve 660 via the solenoid valve 626 and the three-way valve 650 by driving the metering pump 651.

Driving the metering pump 652, from the water tank 617, to the dilution tank 670
A certain amount of water On the way, the plating solution sample in the sample loop 661 described above is simultaneously sent to the dilution tank 670 and diluted 50 times.

After opening the solenoid valve 681, nitrogen gas is flown into the dilution tank 670 for a short time to stir the liquid.

The six-way valve 666 is switched so that a part of the 50-fold diluted sample in the dilution tank 670 is sent to the sample loop 667, and the metering pump 656 is driven to dilute the diluted sample into the sample loop 667.
Send to

H ₂ O is constantly fed to the anion exchange membrane tube 201 at a flow rate of 2 ml / min by the metering pump 657. Further, by switching the six-way valve 666, the diluted sample collected in the sample loop 667 is sent to the anion exchange membrane tube 201.

Outside the anion exchange membrane tube 201 of the anion exchanger 202, for example, a 0.2 N-KCl solution stored in a regenerating solution tank 619 is sent at a flow rate of, for example, 2 ml / min by a metering pump 658. The ion-exchange membrane tube 201 is always regenerated to a chlorine ion type. This anion exchange membrane tube 201
When the plating solution sample is sent into the inside, the sulfite ion, thiosulfate ion, gold complex and the like in the plating solution are captured on the anion exchange membrane, and chloride ion is eluted instead.

On the other hand, since thiourea as a reducing agent is a nonionic substance, it is sent to the ultraviolet absorption detector 203 together with the eluted chlorine ions without being captured in the anion exchange membrane tube 201.

The measurement wavelength of the ultraviolet absorption detector 203 is set to 240 nm at which thiourea absorbs. Since chloride ions do not show absorption at 240 nm, the absorbance is measured only with thiourea.

By driving the metering pump 657 again, the sample loop 667
A 50-fold diluted sample is collected therein, and the same operation is repeated, and the absorbance is measured twice.

 The measurement of the concentration of the gold component in the plating solution is performed as follows.

A six-way valve 664 is connected so that a part of the 50-fold diluted sample in the dilution tank 670 is sent to the sample loop 665, and the metering pump 656 is driven to send the diluted sample to the sample loop 665.

The metering pump 655 is driven for a certain period of time to insert a certain amount of water into the dilution tank 672. On the way, the six-way valve 664 is switched, and the diluted sample in the sample loop 665 is sent into the dilution tank 672, for example, diluted 100 times. Open solenoid valve 682,
Stir with nitrogen gas. A part of the sample in the dilution tank 672, which has been diluted in two steps, is analyzed by the autosampler 101 using an atomic absorption spectrophotometer.
It is sent to 02 to measure the gold concentration.

Again, the autosampler 101 is operated to sample the diluent and measure the gold concentration.

After the measurement, the solenoid valves 671 and 673 are opened to discard the diluted sample, and H ₂ O is sent by the metering pumps 652 and 655 to wash the dilution tanks 670 and 672. Also open the solenoid valve 625 and open the metering pump 6
Drive 51 to wash the plating solution collection piping.

The arithmetic control means 401 measures the average value of the measured values of the concentration of the gold component in the plating solution and the measured value of the concentration of the reducing agent component in the plating solution obtained by the two measurements, and measures the standard solution twice. The proportional calculation with the average value of the calibration values thus performed is performed as in equation (1) to calculate the concentrations of gold and thiourea in the plating solution.

Desired plating solution concentration Even when the measuring device has a background, if the standard solution and the target control concentration are substantially the same, the error in the vicinity of this is very small.

Of course, the method for measuring the concentration is not limited to the above method, and a calibration curve may be created using several types of standard solutions having different concentrations.

The arithmetic control means 401 checks whether the calculated concentration and pH value of the plating solution are within the allowable range of the set concentration. If the value is out of the allowable range, the worker is notified by an alarm and the measurement is performed again or the measurement is confirmed. In this way, erroneous management based on erroneous measured values is prevented.

Further, the arithmetic and control unit 401 calculates the replenishment amount by obtaining the consumption of the component accompanying the progress of the plating from the difference between the calculated concentration of the plating solution and the set concentration. In the replenishment, the operation time of the solenoid valve and the drive time of the pump need to be changed according to the replenishment amount.

The replenishment from the metal component replenisher bath 614 and the reducing agent replenisher bath 615 to the plating bath is performed by opening the electromagnetic valves 631 to 635 and operating the metering pump 653.

The replenishment time of gold and thiourea is calculated from the concentration of the replenisher of gold and thiourea, the volume of the plating tank, the flow rate of the metering pump 653, etc., and the solenoid valves 636 and 637 are sequentially opened for a predetermined time to reduce the required amount. refill.

The replenishment of the pH adjusting solution is performed by opening the solenoid valve 638 for a preset replenishing time according to the measured value of the pH of the plating solution.

After replenishment of each replenisher, the solenoid valve 639 is opened for a certain time each time, and the piping system is washed with water.

Further, the arithmetic and control means of the present embodiment comprises an anion exchanger
It has a program to check 202 ion exchange capacity.

If only the thiourea concentration in the plating solution exceeds the allowable range, the cause may be a decrease in the ion exchange capacity of the anion exchanger 202. At this time, the check can be performed by the following operation (automatic) by the operator's selection of the program.

This program selection can be instructed from an input device such as a keyboard (not shown) of the arithmetic control means 401.

That is, the solenoid valve 624 is opened and the Na ₂ S ₂ O
₃ Collect the solution in the sample loop 661 and dilute it into the dilution tank 670.
After dilution in the same way, in the same manner as the thiourea concentration measurement,
The absorbance is measured by the ultraviolet absorption spectrophotometer 203.

If the ion exchange capacity of the anion exchanger 202 is normal, all thiosulfate ions are captured on the anion exchange membrane, and chloride ions are eluted instead, so that the ultraviolet absorbance becomes zero. However, if the anion exchange capacity decreases,
Since part or all of the thiosulfate ions are sent to the ultraviolet absorption detector 203 as they are, they show some absorbance, and abnormalities can be easily found.

Hereinafter, the operation of the embodiment described above will be described.

Reducing ions such as sulfite ions and thiosulfate ions;
When a plating solution containing a sulfite ion or a gold complex having a thiosulfate ion as a ligand is passed through an anion exchange membrane to which chloride ions are adsorbed, sulfite ions or thiosulfate ions having a high affinity for anion exchange substances are generated. Anion exchange material is trapped, and an equivalent amount of chloride ion is eluted instead.

Thus, the reducing ions contained in the plating solution are exchanged for anions which do not interfere with the measurement of the quantitative analysis of the reducing agent contained in the plating solution.

However, thiourea is not trapped by the anion exchange membrane because of its nonionicity, and flows out of the anion exchanger as it is. The concentration of thiourea can be accurately measured by an ultraviolet absorption detector provided after the anion exchanger because chlorine ions do not show ultraviolet absorption.

If the reducing agent is a substance that does not exhibit ultraviolet absorption, such as formaldehyde, for example, an electrochemical quantification device, for example, a potentiometric titration device is provided instead of an ultraviolet absorption detector. The concentration can be calculated from the amount. Also at this time, the chlorine ions do not interfere with the measurement. A coulometric device, a voltammetric device, or the like can also be used as the electrochemical quantitative device.

In order to perform the quantitative analysis of the gold component, an analyzer such as plasma emission spectroscopy may be used instead of the atomic absorption method. However, in general, the plasma emission spectroscopy requires a larger measuring device than the atomic absorption method.

In particular, in the concentration control device of Example-3, not only the metal component but also the standard solution in which the metal component and the reducing agent component were mixed was used as the standard solution for the atomic absorption spectrophotometer, and the measurement which tends to occur by the atomic absorption method Prevent value fluctuations. Further, by mixing the metal component and the reducing agent component immediately before the measurement, a standard solution that does not undergo liquid decomposition can be prepared, and accurate measurement can be performed.

The pH is measured once a day, but may be measured a plurality of times.

In the present embodiment, the measurement and calibration by the measurement device are controlled by using a sequencer to perform automation, but without using a sequencer, using an arithmetic control unit,
Measurement and calibration control by the measurement device may be performed.

The arithmetic control unit fetches the measured value and the calibration value sent from the measuring device, and calculates the concentration in accordance with the above equation (1). From the difference between the determined concentration of the plating solution and the set concentration, the amount of component consumption accompanying the progress of plating is determined to calculate the replenishment amount. Then, according to the information on the amount of the consumable component, the amount of the consumed component is successively replenished from the replenishing solution tank, so that the component concentration of the plating solution is always managed within a certain range. As a result, the plating speed can be kept constant.

Further, the arithmetic and control means performs an abnormality test of the calibration value and an abnormality test of the measured value of the component concentration of the plating solution. Depending on the calibration value and the measured value, remeasurement and checking of the apparatus are immediately performed. Thus, the reliability of the measured value is improved.

The concentration and the concentration of gold and thiourea were measured every hour by using the concentration control device of Example-3, and a replenishment of the pH adjusting solution, the gold and thiourea replenisher was performed, and the load was adjusted to 1 dm ² /. About 2
The plating was performed for 0 hours.

At this time, the plating rate was adjusted to the range of 1.0 to 0.85 μm / hour because the pH was 9 to 9.1, the gold concentration was automatically controlled to within the set concentration ± 5%, and the thiourea concentration was automatically controlled to within the set concentration ± 3%. We were able to.

Almost the same results were obtained with the concentration control device of Example-2.

As described above, since the concentration control device of the present invention keeps the plating speed constant during the progress of plating, uniform plating without unevenness can be performed. That is, the concentration control device of the present embodiment can be used as an excellent plating device.

Further, the concentration control apparatus of the present invention controls the concentration of the plating solution components by appropriately changing the replenisher and the standard solution depending on the plating solution components to be used in various plating solutions other than the non-cyanide electroless plating solution. can do. Similarly, the present invention can also be applied to a non-cyanide electroless plating apparatus.

In the concentration control devices of Examples 2-3, an atomic absorption spectrophotometer is used for the concentration analysis of the gold component, but it is possible to provide a metal component concentration measuring means that selects an analyzer suitable for the metal component to be measured. it can. Similarly, although an ultraviolet absorption detector is used for the analysis of the concentration of the reducing agent component, a nonmetallic component measuring means capable of measuring the concentration of nonmetallic components other than the reducing agent can be provided.

The arithmetic and control unit of the concentration management device including the metal component measuring unit and the non-metal component measuring unit as described above is described in Example-
The arithmetic control means as described in 2 and 3 can be used.

For example, a polarograph as a metal component measuring means,
For example, a concentration control device equipped with a liquid chromatograph as a nonmetallic component measuring means is not a plating tank, for example,
By connecting to a waste liquid tank such as a factory wastewater, the metal component measuring means measures, for example, the concentration of cadmium, and the nonmetallic component measuring means measures, for example, the concentration of an organic substance such as ketone, so that the water quality of the factory wastewater can be controlled. . At this time, the standard solution and the replenisher used are appropriately changed according to the metal component and the nonmetal component contained in the factory wastewater.

[Effects of the Invention] As described in detail above, in the method for adjusting the component concentration of the plating solution of the present invention, an anion shared in the plating solution is converted into another anion species that does not disturb the measurement of the reducing agent. Thus, the concentration of the reducing agent can be measured, so that the concentration of the reducing agent in the plating solution can be measured with high accuracy.

Furthermore, if the apparatus using the above method is provided with a function of calculating and replenishing the consumption of the plating solution, the component concentration of the plating solution can be constantly adjusted within a certain range, and automatic management of the plating solution can be performed. Can be achieved.

Further, the concentration management device using the concentration adjustment method of the present invention, which has a metal component concentration measurement unit, a non-metal component concentration measurement unit, and an arithmetic control unit, measures the concentration of the metal component and the concentration of the non-metal component in the solution. Can be measured. When each measured value is out of the predetermined control range, the arithmetic and control unit operates to add the replenisher stored in the replenisher tank to keep the concentration of each component of the solution within the control range. Can be.

[Brief description of the drawings]

FIG. 1 is a system diagram showing the configuration of an embodiment of a concentration measuring device used in the concentration adjusting method of the present invention, and FIG.
FIG. 3 is an ultraviolet absorption spectrum diagram of urea and KCl, FIG. 3 is a system diagram showing a configuration of one embodiment of a concentration adjusting device used for concentration adjustment of the present invention, and FIG. 5 is a system diagram showing an embodiment of a plating apparatus to be performed, and FIG.
FIG. 6 is a flowchart showing the operation of the arithmetic and control means used in the embodiment shown in FIG. 4. FIG. 6 shows the change over time of the components when plating is performed using a non-cyanide plating solution without adding a replenisher. FIG. 7 is a graph showing the change over time of the components and the change over time of the plating rate when plating is performed using a non-cyanide plating solution with the addition of a replenisher as the plating progresses. 7 ... anion exchanger, 8 ... anion exchange membrane tube, 9 ... ultraviolet absorption detector, 10 ... arithmetic and control unit, 11 ...
... gold standard solution tank, 12 ... thiourea standard solution tank, 13 ... plating tank, 14 ... gold supplementary replenishment tank, 15 ... thiourea replenishment solution tank, 35 ...
… Atomic absorption spectrophotometer, 610 …… Metal component standard liquid tank, 611 ……
Reducing agent standard solution tank, 612 …… pH buffer solution tank, 613 …… Na ₂ S ₂ O ₃
Solution tank, 614 ... Metal component replenishment tank, 615 ... Reducing agent replenishment tank, 616 ... pH adjustment liquid replenishment tank, 618 ... Reducing agent addition liquid tank, 619 ... Regeneration liquid tank, 101 ... Autosampler, 102
…… Atomic absorption spectrometer, 201 …… Anion exchange membrane tube, 202 …… Anion exchanger, 203 …… UV absorption detector,
301: Flow cell, 302: pH electrode, 303: pH meter, 401: Operation control means.

Claims (2)

(57) [Claims] 1. A method for adjusting a component concentration of a plating solution containing a metal component, an anion and a reducing agent, wherein the anion is replaced by another anion species which does not interfere with the measurement of the concentration of the reducing agent. Thereafter, a step of measuring the reducing agent concentration and the metal component concentration; a step of calculating a consumption amount of the reducing agent and the metal component based on the measured reducing agent concentration and the metal component concentration; and Replenishing the plating solution with a replenisher containing a reducing agent and a metal component corresponding to the above, wherein the metal component is a gold ion, the anion is at least one of a thiosulfate ion and a sulfite ion, The method according to claim 1, wherein the reducing agent is thiourea, and the other ionic species is at least one of a chloride ion and a carbonate ion. 2. A plating method, wherein gold plating is performed using a plating solution whose component concentration has been adjusted using the component concentration adjusting method according to claim 1.