JP3437600B2 - Method and apparatus for automatic analysis of solder plating solution - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder plating solution automatic analysis method and apparatus , and more particularly to a solder plating solution automatic analysis method and apparatus for sampling and automatically analyzing a solder plating solution during a solder plating process.

[0002]

2. Description of the Related Art Recently, solder plating has been frequently applied to electronic parts. Solder plating baths for this solder plating include fluoric acid baths and organic sulfonic acid baths. Solder plating obtained with a borofluoric acid bath has good physical properties and is often used, but it is not possible to obtain high-quality plating with high current density, wastewater treatment is difficult, or wastewater standards are strict. For this reason, organic sulfonic acid baths have recently been used. Therefore, in order to obtain a conductive solder plating film having an adhesive function required for electronic parts such as lead frames, it is necessary to control the composition concentration of the solder plating bath. In this case, the composition to be controlled is a free acid that gives conductivity to the plating bath, Sn ²⁺ , Pb ²⁺ that constitutes the plating film, and an additive used to obtain a plating film with stable quality. Therefore, it is necessary to maintain those concentrations within the set control concentration and standard control range. In order to control the composition concentration of the plating bath with the standard control width, it is necessary to accurately analyze the composition concentration of the solder plating solution in the solder plating process, but conventionally, it took a lot of time to analyze manually. is doing.

[0003]

However, in the above-mentioned conventional analytical method, Sn ²⁺ , free acid, Pb ^{2+ are used.}
In order to analyze the above, there is a problem that three analysis containers must be used and must be analyzed manually.
Further, in the case of the organic sulfonic acid bath, there is a problem that the concentration of the additive must be separately analyzed.

The present invention has been made in view of the above circumstances, and it is possible to quantitatively analyze Sn ²⁺ , free acid and Pb ²⁺ in a solder plating solution in a solder plating process in one analysis container. It is an object of the present invention to provide a solder plating solution automatic analysis method and apparatus capable of analyzing the additive concentration in the additive concentration analysis unit after pretreatment of the solder plating solution in the analysis container.

[0005]

In order to achieve the above-mentioned object, the solder plating solution automatic analysis method of the present invention comprises a sampling step of sampling the solder plating solution in the solder plating step and transferring it to a container for analysis, Repeat the analysis process for analysis and the cleaning process for cleaning after analysis, 1
It is characterized in that Sn ²⁺ , free acid and Pb ²⁺ are analyzed in one analysis container.

Further, the method for automatically analyzing a solder plating solution of the present invention comprises a pretreatment step of performing a pretreatment such as dilution of the solder plating solution using the analysis container, and a solution obtained through the pretreatment step as an additive concentration. And an analysis step of analyzing the additive concentration in the analysis section.

[0007]

According to the present invention having the above-mentioned structure, the solder plating solution in the solder plating step is sampled and transferred to the analysis container, and Sn ²⁺ , free acid, P
Quantitative analysis of any one of b ²⁺ , for example Sn ²⁺ ,
After draining the analyzed solder plating solution, wash the analysis container and electrodes, etc., again sample the solder plating solution in the solder plating process and transfer it to the analysis container, the components analyzed in the previous analysis Of the remaining two components except for the free acid, for example, the free acid is quantitatively analyzed, washed after the analysis, and the solder plating solution is sampled and transferred to a container for analysis. By performing a quantitative analysis of ²⁺ and performing a final washing, Sn ²⁺ , free acid, Pb
²⁺ analyzes can be performed in one analytical vessel. Furthermore, after performing the analysis for the three components, the solder plating solution in the solder plating step is sampled and transferred to an analysis container, and after performing a pretreatment such as dilution of the solder plating solution in the analysis container, The additive concentration can be analyzed by guiding it to the additive concentration analysis unit.

[0008]

EXAMPLE An example of an automatic solder plating solution analyzing method according to the present invention will be described below with reference to FIG. A circulation bath 2 for analyzing a solder plating solution, which is connected via a pipe to a solder plating bath 1 in the solder plating process, is installed. Solder plating tank 1 and circulation tank 2 for solder plating solution analysis
Are connected by a supply pipe 3a and a return pipe 3b, and a circulation sampling pump P is connected to the supply pipe 3a.
₁ and the valve V ₁ are installed, and by constantly operating the circulation sampling pump P ₁ , the solder plating solution is taken out from the solder plating tank 1 during the solder plating process into the solder plating solution analysis circulation tank 2 and Is returned to the solder plating tank 1.

An analysis container 4 is installed adjacent to the solder plating solution analysis circulation tank 2, and a PH electrode 5 and a redox electrode 6 are installed in the analysis container 4. A light emitting portion 7a and a light receiving portion 7b are provided outside the analysis container 4.
A transparency measuring device 7 is installed. A magnetic stirrer 8 is installed outside the bottom of the analysis container 4 so that the liquid in the analysis container 4 is agitated. A waste liquid pipe 3c is connected to the bottom of the analysis container 4, and an electromagnetic valve V ₂ is interposed in this pipe 3c.

A sampling container 10 is provided for sampling the solder plating solution from the solder plating solution analysis circulation tank 2 and transferring it to the analysis container 4. The sampling container 10 is a sampling mechanism (not shown). This enables the solder plating solution analysis circulation tank 2 and the analysis container 4 to move as indicated by the broken line.

A sampling pipe 3d is connected to the sampling container 10, and a sampling pump P ₂ is connected to the pipe 3d. As a result, after the sampling container 10 is inserted into the solder plating solution analysis circulation tank 2 by the sampling mechanism, the sampling pump P ₂ is operated to suck a predetermined amount of the solder plating solution,
After that, the sampling container 10 is moved to the analysis container 4, and the solder plating solution is transferred from the sampling container 10 into the analysis container 4.

When the sampling container 10 reaches the position of the analysis container 4, it is connected to the pure water pipe 3e. A valve V ₃ and a pure water pump P ₇ are installed in the pure water pipe 3e, and the ends thereof are connected to a pure water tank T _1. After discharging the solder plating solution from the sampling container 10, sampling is performed. Container 1
The solder plating solution adhering to the wall surface of No. 0 is cleaned and removed with pure water.

A suction supply pipe 3f is provided in the analysis container 4.
Is inserted, the pipe 3f is connected to the additive concentration analysis unit 12 via the three-way valve V ₄ , and the pipe 3f is connected to the suction pump P ₃ via the three-way valve V ₅ . . The NO port of the three-way valve V ₅ is the waste liquid pipe 3c.
It is connected to the. The additive concentration analysis unit 12 includes a flow cell 12a, a light emitting unit 12b, and a light receiving unit 12c.

A cleaning reagent tank T ₂ , a titration reagent tank T ₃ and a standard solution reagent tank T ₄ are installed adjacent to the pure water tank T ₁ . Note that in FIG. 1, each of the reagent tanks T _{1 to} T ₄ is shown for the sake of simplification, but in reality, each is composed of a plurality of reagent tanks. The reagent tank T ₂ is inserted reagents pipe 3g reagent pump P ₄ is installed, titrated pipe 3h the titration pump P ₅ is installed is inserted into the titration reagent tank T _3, further standard solution for standard solution pipe 3i standard pump P ₆ is installed in the reagent tank T ₄ is inserted. In FIG. 1, the pumps P ₄ to
Although each P ₆ is shown in the figure, it is actually composed of a plurality of pumps corresponding to the reagent tanks.

Next, a solder plating solution automatic analysis method using the apparatus configured as described above will be described. The circulation sampling pump P ₁ is always operating, the solder plating solution is taken out from the solder plating tank 1, circulates in the solder plating solution analyzing circulation tank 2 and returns to the solder plating tank 1 again. First, after inserting the sampling container 10 into the circulation bath 2 for analyzing the solder plating solution, the sampling pump P ₂ is operated to suck a predetermined amount of the solder plating solution into the sampling container 10, and then the sampling mechanism is operated again. Then, it is brought to the position of the analysis container 4, and the solder plating solution in the sampling container 10 is discharged and transferred to the analysis container 4. At this time, although the solder plating solution adheres to the wall surface of the sampling container 10, the pure water pump P
₇ , the valve V ₃ is opened, pure water is supplied into the sampling container 10 through the pipe 3e to wash the inside of the sampling container 10, and the sampling container 1
All of the solder plating solution attached to 0 is transferred to the analysis container 4.

Next, the three-way valve V ₄ is switched to operate the pure water pump P ₇ , pure water is supplied into the analysis container 4 through the branch pipe 3j, the three-way valve V ₄ and the pipe 3f, and the solder is applied. The plating solution is diluted to generate a predetermined amount of analysis solution. Then, the reagent pump P ₄ is operated to add the titration reagent, and then the titration pump P ₅ is operated to perform titration to analyze Sn ²⁺ . At this time, the redox titration with a specified iodine solution is used for the analysis of Sn ²⁺ , and the redox electrode 6 is used as a detection sensor of the end point. After the Sn ²⁺ quantitative analysis is completed by this titration, the analytical container 4 and the electrodes 5 and 6 are washed. That is, by operating the reagent pump P ₄ , the reagent tank T
After supplying a predetermined cleaning reagent from ₂ to the inside of the analysis container 4, the water is drained, and then the pure water pump P ₇ is operated to supply pure water to the analysis container 4 to wash the pure water. Open ₂ and drain pure water.

Next, the sampling mechanism is operated again to sample a new solder plating solution (predetermined amount) by the sampling container 10 and transfer it to the analysis container 4.
The details of this sampling are the same as those described above, and will be omitted. Then, the pure water pump P ₇ is operated to supply pure water to the analysis container 4, and the solder plating solution is diluted to generate a predetermined amount of analysis solution. Next, the titration pump P ₅ is operated to perform titration to quantitatively analyze the free acid. At this time, neutralization titration with a normal sodium hydroxide solution is used for analysis of free acid, and the PH electrode 5 is used as a detection sensor at the end point.

After the free acid analysis is completed by this titration, the analysis container 4 and the electrodes 5 and 6 are washed. That is, the reagent pump P ₄ is operated to supply a predetermined cleaning reagent from the reagent tank T ₂ to the analysis container 4 and then drained, and then the pure water pump P ₇ is used to perform pure water cleaning.

When the free acid analysis is completed through the above steps, the sampling mechanism is operated again to sample a predetermined amount of the solder plating solution from the solder plating solution analysis circulation tank 2 by the analysis container 4 and analyze the container 4 for analysis. Move to. Then, the pure water pump P ₇ is operated to supply pure water to the analysis container 4, and the solder plating solution is diluted to generate a predetermined amount of analysis solution. Next, the reagent pump P ₄ is operated to add the titration reagent, and then the titration pump P ₅ is operated to perform the titration Pb
Perform ²⁺ quantitative analysis. At this time, the standard E is required for the analysis of Pb ^2+.
Chelate photometric titration with a DTA solution is used, and a transmittance measuring device 7 in a specific wavelength range is used as a detection sensor at the end point. After the titration is completed, the reagent pump P ₄ is operated to supply the cleaning reagent and drain it, and then the pure water pump P ₇ is operated to perform pure water cleaning.

After the above steps, Sn ²⁺ , free acid and Pb ²⁺ are analyzed in one analytical container 4, and then the additive concentration is analyzed. In this additive analysis step, first, the pure water pump P ₇ is operated to operate the pipe 3j, the three-way valve V ₄ and the pipe 3f.
A predetermined amount of pure water is put into the analysis container 4 via the above, and after draining, the pure water pump P ₇ is operated again to put a predetermined amount of pure water into the analysis container 4. Then, the suction pump P ₃ is operated to guide the pure water to the flow cell 12a of the additive concentration analysis unit 12, and the absorbance is measured by the light emitting unit 12b and the light receiving unit 12c, and the absorbance of this pure water is taken as a zero point. After draining this pure water, the sampling mechanism is operated to sample a predetermined amount of the solder plating solution by the sampling container 10 and transfer it to the analysis container 4. Then, the pure water pump P ₇ is operated to supply pure water to the analysis container 4, and the solder plating solution is diluted to generate a predetermined amount of analysis solution.

Next, the suction pump P ₃ is operated to guide the analysis solution to the flow cell 12a of the additive concentration analysis section 12, and the absorbance is measured by the light emitting section 12b and the light receiving section 12c. 4 and the additive concentration analysis unit 12 to waste liquid. Then, pure water is supplied from the pure water pump P _7, and the analysis container 4, the electrodes 5, 6 and the additive concentration analysis unit 12 are supplied.
To wash. After that, the analysis container 4 and the like are washed with a washing reagent and pure water.

After the above steps are repeated a predetermined number of times, cleaning is performed by chemical cleaning in order to remove the analysis product attached to the analysis container 4, the electrodes 5 and 6 in the analysis container 4 and the additive concentration analysis section 12. Carry out the process. In this cleaning step, the reagent pump P ₄ is operated to supply hydrochloric acid from the reagent tank T ₂ to each cleaning location, and after immersion for a predetermined time (for example, 60 minutes), drainage is performed and the pure water pump P ₇ is operated. Repeat pure water cleaning multiple times.

When the analysis of Sn ²⁺ , free acid, Pb ²⁺ and additive concentration is repeated a predetermined number of times, PH calibration and / or additive calibration becomes necessary. Next, the PH calibration process and the additive calibration process will be described. First, the liquid remaining in the analysis container 4 is drained, and then the standard liquid pump P ₆ is operated to put a predetermined amount of PH7 standard liquid into the analysis container 4. Next, this liquid is drained, and a predetermined amount of P is again used.
Pour the H7 standard solution into the analytical container 4, measure the PH, and
The calibration of H7 is completed.

After draining the waste liquid, washing with pure water is carried out, and this time, a predetermined amount of PH4 standard liquid is put into the analytical container 4. Then, after draining the liquid, a predetermined amount of the PH4 standard liquid is put into the analysis container 4 again, the PH is measured, and the PH calibration is completed. Finally, the liquid is drained and then washed with pure water.

On the other hand, in the additive calibrating process, the pure water pump P ₇
Is operated to put a predetermined amount of pure water into the analysis container, and after draining, a predetermined amount of pure water is put into the analysis container 4 again, and then the suction pump P ₃ is operated to add pure water to the additive concentration. It leads to the analysis unit 12. Then, after measuring the absorbance of pure water, the water is drained, and the standard solution (predetermined amount) is supplied to the standard solution pump P this time.
Run ₆ and put in container 4 for analysis. Then, the deionized water pump P ₇ is operated to supply deionized water to the analytical container 4 to dilute the standard liquid to produce a predetermined amount of liquid. Then, this solution is introduced into the additive concentration analysis unit 12 and the absorbance is measured to prepare a calibration curve. Finally, after draining the liquid, the reagent pump P ₄ is operated to introduce a predetermined amount of cleaning reagent to the additive concentration analysis unit 12, and after the waste liquid is drained, the pure water pump P ₇ is operated to perform pure water cleaning.

In the embodiment described above, Sn ²⁺ ,
Although an example in which the solder plating solution is analyzed in the order of free acid, Pb ²⁺ , and additive concentration has been described, the composition concentrations can be analyzed without being limited to this order. Further, although the embodiment in which the present invention is applied to the organic sulfonic acid bath has been described, the present invention can of course be applied to the borofluoric acid bath.

[0027]

As described above, according to the present invention, a sampling step of sampling the solder plating solution in the solder plating step and transferring it to an analysis container, an analysis step of performing a quantitative analysis, and a cleaning step after the analysis are performed. By repeating the washing process sequentially, Sn ²⁺ , free acid, P
The b ²⁺ analysis can be performed automatically.

Further, according to the present invention, after performing a pretreatment such as dilution of a solder plating solution using the analysis container,
The additive concentration can be automatically analyzed by guiding it to the additive concentration analysis unit. Therefore, according to the present invention, the additive concentration can be analyzed in addition to the composition concentration of Sn ²⁺ , free acid and Pb ²⁺ , and all the components of the solder plating bath consisting of the organic sulfonic acid bath are automatically analyzed. Can be analyzed. In addition to this, according to the present invention, PH calibration and additive calibration can be automatically performed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of a solder plating solution automatic analysis method according to the present invention.

[Explanation of symbols]

1 Solder plating bath 2 Solder plating solution analysis circulation tank 3 piping 4 Analytical containers 5 PH electrode 6 Redox electrode 7 Transmittance measuring instrument 8 magnetic stirrer 10 Sampling container 12 Additive concentration analysis section

Claims (9)

(57) [Claims] 1. A sampling container for sampling a solder plating solution in a solder plating process and transferring it to an analysis container, an analysis process for quantitative analysis, and a cleaning process for cleaning after analysis are repeated one by one. And Sn ²⁺ ,
A solder plating solution automatic analysis method, characterized by performing analysis of free acid and Pb ²⁺ . 2. A pretreatment step of performing a pretreatment such as diluting a solder plating solution using the analysis container, and an analysis of analyzing the additive concentration in the additive concentration analysis section of the solution which has undergone the pretreatment step. The solder plating solution automatic analysis method according to claim 1, further comprising a step. 3. A plating solution during the solder plating process
Sampling process for ringing and quantitative analysis for quantitative analysis of the plating solution sampled
Analyze the analysis step and the additive concentration of the sampled plating solution.
And an additive concentration analysis step of
Automatic plating solution analysis method. 4. Additive calibration after the step of claim 3.
A method for automatically analyzing a solder plating solution, which is characterized by performing. 5. The quantitative analysis step comprises Sn ²⁺ , free
A quantitative analysis of acid and Pb ²⁺ is performed.
3. The automatic solder plating solution analysis method described in 3. 6. The quantitative analysis step is performed by titration.
The solder plating solution automatic analysis according to claim 3,
Method. 7. A plating solution during the solder plating process
Sampling device for ring and quantitative analysis for quantitative analysis of the plating solution sampled
Analyze the analyzer and the additive concentration of the sampled plating solution.
And an additive concentration analyzer
Automatic plating solution analyzer. 8. The quantitative analyzer comprises Sn ²⁺ , free
A quantitative analysis of acid and Pb ²⁺ is performed.
7. Solder plating solution automatic analyzer according to 7. 9. The quantitative analysis device is operated by titration.
The solder plating solution automatic analysis according to claim 7,
apparatus.