JPS59197555A - Method and apparatus for replenishing metal ion to chemical plating bath - Google Patents

Abstract

PURPOSE:To prolong the life of a chemical plating bath and to enhance the quality of a plating film, by replenishing a plating metal ion to the chemical plating bath by treating said chemical plating bath with a cation exchange resin having the metal ion adsorbed therewith. CONSTITUTION:An ion exchange tower 3 is packed with a weak acidic ion exchange resin 13 which is, in turn, washed with pure water in a storage tank 7. Subsequently, sulfuric acid with a concn. of about 5% is sent to the exchange tower 3 from an acid tank 4 to convert a part of the ion exchange resin 13 to a H type while a caustic soda solution with a concn. of about 4% is sent to the exchange tower 3 from an alkali storage tank 5 to convert the same to a Na type. In the next step, the ion exchange resin 13 is washed with water and, thereafter, a copper sulfate solution with a concn. of about 16% is sent from a copper salt storage tank 6 to convert the Na type to a Cu type through the adsorption of a copper ion. After washing and backwashing are further performed, the chemical plating bath of a copper ion replenishing tank 2 is passed through the ion exchange tower 3 by a pump P-1 to elute the copper ion which is, in turn, again returned to the replenishing tank 2 to be supplied to a chemical copper plating tank 1 through a recirculation tank 10 and a filter 11 while the plating bath of the plating tank 1 is sent to the replenishing tank 2 by the pump P-1.

Description

[Detailed description of the invention] The present invention improves the service life of the chemical plating solution, stabilizes the chemical plating reaction, and improves the quality of the plated product when chemical plating is performed continuously or continuously. Chemical plating of depleted metal ions to the enemy? I am inspired by IW feeding methods and devices.

Generally, chemical plating, especially chemical copper plating, is widely used industrially as a plating method for printed wiring boards and other electronic equipment parts.
As a result, copper precipitation inevitably causes a decrease in copper ions, resulting in a significant loss in the copper precipitation rate.

In order to compensate for the consumption of copper ions due to such chemical plating reactions, it has been necessary to increase the copper bath solution, especially the copper gravel bath solution. Therefore, if chemical copper plating solution is used continuously,
In the chemical plating solution, sulfate ions that are not consumed in the plating reaction accumulate, p+-+ Also, the alkali metal hydroxide added to adjust the state of the solution, especially sulfuric acid, which is a reaction product with sodium hydroxide. vinegar)
l) Lamb accumulates and the salt concentration in the plating solution increases.

This salt accumulation deteriorates the stability of the chemical copper plating solution,
This results in a significant decrease in the deposition rate and, in turn, in the ductility and tensile strength of the deposited film.

Therefore, in the past, focusing on the fact that the specific gravity of the chemical plating solution increases as the salt concentration in the chemical plating solution increases, the entire chemical plating solution was removed when the specific gravity of the chemical plating solution exceeded a certain value. Either the chemical plating solution was discarded and replaced with a new chemical plating solution, or a part of the chemical plating solution was discarded and a new chemical plating solution was added. In any case, in the conventional chemical steel plating method, the chemical plating solution had to be thickened due to the high salt concentration.

By the way, the chemical plating solution to be discarded has a concentration of 1% CO.
L) Since it contains complexing agents and heavy metals, its waste liquid treatment is extremely difficult and necessarily requires a large amount of cost. Furthermore, even if some of the chemical plating solutions were to be replaced, the cost of setting up the chemical plating solution would be costly and would easily account for a proportion of the plating cost, which was a problem.

In order to solve these problems, one method that has already been proposed is to evaporate water under reduced pressure and remove sodium sulfate by crystallization.Another method is to remove sodium sulfate by crystallization. This is a method of removing ions. The former method uses thermal engineering, which is not preferable from an energy-saving perspective, and in order to remove crystallization, it is necessary to avoid the presence of sodium sulfate at a good concentration in the electroless steel plating solution. must not. However, products of good quality cannot be expected from such a plating solution. In addition, deionization by electrodialysis not only deionizes the accumulated ions but also removes the complexing agent, which leaves problems in managing the plating solution and processing the concentrated cotton solution.

Since all of these improvement measures are methods for removing salts accumulated in the plating solution, sulfates, which are undesirable for chemical plating, are always present in these electroless plating solutions.

Therefore, a proposal was made for a method of replenishing copper ions to avoid contamination with sulfate ions. As a supplementary wire method for this copper ion, there is a method of replenishing the copper ion by dissolving the metal steel anode, and as the 01 (- ion concentration is high, copper hydroxide is precipitated on the anode surface. It deposits and covers the electrode, reducing the dissolution efficiency of the anode and causing problems.
-1 Yes. Moreover, when the PM content of the solution is high, plating reactions are more likely to occur, and metal steels are often used in electrolytic printing, etc. due to the problem of co-printing. The present invention is based on the idea that, in a chemical copper plating solution, copper f-ion combines with a complexing agent and dissolves.

In other words, the non-invention is to apply a chemical plating solution, such as a chemical copper plating solution, to a cation exchange resin, at least a part of which is a metallic type for plating, such as a prepared cation exchange resin, or a cation exchange resin that coordinates or adsorbs copper ions. By treating with a chelate resin or a mixture thereof, plating metal ions, such as copper ions, are supplied to a chemical plating solution, such as a chemical copper plating solution.

In the present invention, a metal salt solution is passed through an H-type cation exchange resin or a chelate resin in advance to perform ion exchange, and the H-type H ions are replaced with metal ions. The chelate resin coordinates or adsorbs the metal ions, and only the fluorescent ions are captured by the ion exchanger and/or the chelate resin, and the captured metal ions are eluted into the plating solution, so the anions are separated. , therefore only metal ions can be replenished.

Metal ions, such as copper ions, are desorbed from this metal type, for example, prepared cation exchange resin, using a metal ion chelating agent (complexing agent), such as a copper ion chelating agent, present in the chemical plating solution. In other words, it is thought that this is due to the complexing agent. This desorption is preferably carried out in an alkaline range of 411 or less to an acidic range. For example, in the high alkaline areas of more than 11 states,
When a chemical copper plating solution is passed through a prepared ion exchange resin to desorb copper ions, a reduction reaction of copper ions occurs within the ion exchange resin layer over a long period of time, and the ion exchange resin Copper precipitates inside. In order to suppress the reduction reaction of copper ions in the ion exchange resin PICO during the desorption of copper ions with the chemical copper plating solution, the chemical copper plating solution is passed through an H-type cation exchange resin in advance to dealkalize it or By making a part of the ion exchange resin of the ion exchange resin layer through which the liquid passes through, the level of the chemical steel l-1 plating solution through which the liquid passes can be maintained at 11 or less, and the ion exchange resin layer can be maintained at 11 or less. Reductive precipitation of copper ions within the fat layer can be prevented.

In accordance with the second aspect of the present invention, the cation exchange resin is ion-exchanged with a chemical plating solution, such as a chemical copper plating solution, in a metal form, for example, in a prepared form, to form a chemical metal plating solution, such as a chemical copper plating solution, with metal ions, e.g. Any of strongly related cation exchange resins, weakly hostile cation exchange resins, and weakly hostile cation exchange resins that can elute copper ions can be used.

Among these 1-field ion-based resins, it is desirable to use a weakly hostile cation exchange resin because it has a large ion exchange capacity and is easy to mix in adsorption and desorption. However, even in these cases, it is particularly desirable to use macroporous, weakly acidic, cationic, parent-converted resins.

In this specification, the term "chemical plating solution" refers to a chemical plating solution for copper, nickel, cobal [, zinc, and other metals] that uses metal ions and a chelating agent (complexing agent) for the metal ions. If so, there is no problem even if it contains any other ingredients.In addition, this term
It also refers to chemical plating and additives that have consumed metal ions during operation, such as water sensitizing sodium baths, and other ingredients.

In addition, the term 1-Chemical copper plating solution refers not only to the chemical plating solution that has depleted copper ions during the chemical steel plating operation, but also to the chemical copper plating solution during the operation. .

In addition, in the present invention, the ion exchange operation is performed by bringing the ion exchange resin or chelate resin into contact with the chemical plating solution.
Any ion exchange operation method can be used for n. The method and apparatus of the present invention will be explained below with reference to the drawings.

The figure is a flow sheet of chemical steel plating according to one embodiment of the present invention.

1. Copper ion desorption process A part of the chemical copper plating solution 1', which has been depleted of copper ions by the chemical copper plating reaction in the chemical steel plating bond 1, is sent to the copper ion supply 41iI2 by the pump P-3.

At the same time, by pump P-2, this amount of liquid is
A chemical plating solution in which copper ions have been eluted from the prepared ion exchange resin 13 is sent from the copper ion supply tank 2 to the circulation tank 10 of the chemical copper plating machine 1.

This liquid is supplied to the chemical steel plating solution 1' in the chemical steel plating tank 1.
The copper ion hardness of the steel is drilled until it falls within the range of the kanji grade. The chemical steel plating solution in the chemical copper plating @ ina 1 is circulated to the chemical copper plating tank 1 via the circulation #i10 and the filter 11 by the pump P-4. The chemical copper plating sent to the copper ion supply tank 2 by pump P-3 is 1. Pump P
-1, the liquid enters the ion father exchange tower 3 through the valve 14, filter 12, and valve 15, and the liquid flowing out from the ion father exchange tower 3 returns to the copper ion replenishment tank 2 via the valve 20. This t
While circulating the solution, copper ions are eluted from the prepared ion exchange resin 13 into the chemical copper plating solution, thereby increasing the strength of copper ions in the chemical copper plating solution.

Although the mechanism of the ion exchange resin desorbing copper ions from the ion exchange resin 13 prepared in the same manner as this chemical copper plating cannot be clearly explained, it can be assumed that the copper chelating agent in the chemical steel plating solution and the copper ions The bonding force of ion exchange resin 13
This is thought to be due to the fact that q=1 is smaller than the bonding force between the exchange tower and copper ions.

When all the copper ions have been desorbed from the prepared ion exchange resin 13, the copper ions are adsorbed by an ion exchange reaction,
The ion exchange resin 13 is converted into a reconditioned type.

In the adsorption step of copper ions, 1 ton of Na-type weakly acidic cation exchange resin layer is filled into the ion exchange tower 3, pump P-8 is used to pump pure water from the pure water storage tank 7 through the valve 16, and the ion exchange tower is pumped through the valve 16. 3 to wash the ion exchange resin 13 with water. Washing wastewater is discharged from the valve 21 to the wastewater treatment device 24 . After washing with water, for example, 5% sulfuric acid is passed through the ion exchange tower 3 from the branch storage tank 4 via the valves 17 and 16 using the pump P-5, and a part of the ion exchange mt+1013 is regenerated into H type. do. The recycled waste water is discharged from the valve 21 to the single water treatment device 24 .

After the ion exchange resin is pumped from the copper salt storage tank 6, the pump P-
7, for example, a 16% copper sulfate solution is passed through the ion exchange tower 3 through the valve 19 and the valve 16, and the copper ions are adsorbed on the ion exchange resin 13 to form Na-type, r-on, or sulfuric acid. Convert city to type 7111Il. adsorption/dissipationr
i: Shinkai Natl) The ram containing all the ram is discharged from the valve 21 to the waste water treatment device 24. By this adsorption operation, 80'? After the adsorption operation is completed, water is passed from the pure water storage tank 7 to the ion exchange tower 3 via the valve 16 by the pump P-8 and into the ion exchange resin. The remaining copper sulfate is removed by washing with water. The washing liquid is discharged from the valve 21 to the waste water treatment device 24. After washing for 40 minutes, pour pure water into valve 26.
The water is passed through the ion exchange tower 3 for backwashing. By this backwashing operation, the H type ion exchange resin 13 in the ion exchange tower 3 and the prepared ion exchange resin 13 are mixed.

After backwashing, the chemical steel plating solution in the ion supply tank 2 is transferred to the ion exchange tower 3 through the 15 valves by pump P-1.
, -C through the liquid, Isoon:! 1! The water remaining in the exchange tower 3 is pushed out, and this waste water is discharged from the pulp 21.

In this way, chemical copper plating @'tTIi is substituted and filled into the column 3.

Therefore, the valve 21 is closed, the valve 2o is enclosed, and the chemical steel plating solution is passed from the copper ion supply tank 2 to the total ion exchange tower 3, and the copper ions are removed from the prepared ion exchange resin 13 by the chemical steel plating solution. Elute.

That is, the composition CuO,038mol/l//l, E
DTA, 111 mol/l of 2 NaH O and 0.06 mol/l formalin;
The chemical steel plating solution is placed in the gold copper ion supply tank 6 on the shelf 12.1, and the chemical copper plating solution is pumped through the valve 14, the filter 12, the valve 15, and the ion exchange tower 3 by the pump P-1.
Then, via the valve 20, the copper ion supply tank 2 was circulated at SV6 for 1 hour. The / was increased. Use it as a copper ion replenishment solution for this liquid chemical copper plating cypress 1.
Chemical steel plating with a good plating film was achieved.

The ion exchange resin used in this example was macroporous weakly acidic cation Matamata fat (KBC-5 (trade name: 1 ton) manufactured by Japan Filter Integrated Corporation. This ion exchange resin was packed into an ion exchange tower and Regenerated into H type using kanban and washed with water, 4%
After conditioning with caustic no-bath solution and washing with water,
% steel sulfate solution was passed through an ion exchange tower to adsorb copper ions on the ion exchange resin. Water washing was performed for about 60 minutes to remove sulfate ions in the ion exchange tower. This I
The amount of copper ions adsorbed on the ion exchange resin L is approximately 70?
Met.

Next, 4 tons of chemical copper plating solution was prepared. The composition of the liquid is ELITA °2Na O, 11 mol/l, 37
%Hol j-1 Mariy 5ml/L NaOHPii12.2 z,z,2'-dipyridyl 20■/l PE No. 100
It was 0.020 go/l.

The composition of this solution differs from that of ordinary chemical copper plating solutions in that it does not contain copper ions. When 2 tons of this chemical steel plating solution containing no copper ions was put into a copper ion assistant and circulated through the n1 ion exchange tower at SV4 for 30 minutes, the amount of copper ions in the chemical copper plating solution was 0.03.
Mol/lto'h. Furthermore, as a result of circulating fluid for 1 hour,
The amount of copper ions in the chemical steel plating solution in the copper ion replenishment tank rose to H o, o s o mol/l, and the amount of copper ions in the chemical steel plating solution increased to 8 mol/l.
．． It was 2.

Prepare a chemical copper plating solution containing 0.04 mol/l of copper ions, put it into a chemical steel plating bath, and set the plating temperature to 70°C.
, with a plating load of 1ttri7t, the thickness of deposited copper is approximately 30μ
I tried chemical copper plating @ five times in a row with M once.

After these 5 times of chemical copper plating, no sulfate was observed in the chemical copper plating solution. The elongation rate and tensile strength of the deposited copper in the fifth chemical copper plating were almost the same as in the case of a new chemical copper plating solution, that is, in the case of the first time. To replenish the copper ions consumed during the five chemical copper plating reactions, use the copper ion replenishment cap to replenish the copper ion replenisher, copper ion replenisher, copper ion replenisher. The plating solution was pumped. At the same time, the same amount of chemical copper plating solution as the amount sent to this copper ion replenishment tank is sent to the copper ion replenishment tank to maintain the balance of the solution. Ta.

The reducing agent consumed during chemical steel plating was replenished by sending 10% formalin solution from the reducing agent supply and 20% caustic #g from the alkaline agent supply.

As described above, the present invention can prevent the accumulation of salts, which is a drawback of conventional chemical copper plating methods, thereby extending the life of the chemical copper plating solution, improving the quality of the plating film, and reducing the plating cost. can be reduced.

Although the above description has focused on examples of using cationic or fat-converted whole stools, the present invention is not limited by these descriptions.

[Brief explanation of the drawing]

The figure is a flow sheet showing one embodiment of the present invention. In the figure, 1 is chemical plating ycii, 1' is chemical plating ycii, 2 is copper ion replenishment tank, 3 is ion father exchange tower, and 13 is ion night dust. resin, 4 is an acid storage tank, 5 is an alkali storage tank, 6 is a copper salt storage tank, 7 is a pure water storage tank, 23 is a copper concentration controller, 2
4 is a wastewater treatment device. Procedural amendment 1. Case Description 1982 Patent Application No. 68896 2 Title of Invention Method and Apparatus for Replenishing Metal Ions to Chemical Plating Solution 3
Relationship with the case of the person making the amendment Patent applicant 11mi Address 1-11 Omori Kita, Ota-ku, Tokyo Name Nippon Filter Co., Ltd. 4 Agent 7 Contents of amendment (1) Patent claim The range is as shown in the attached sheet. (2) Detailed explanation of the invention is as follows: 1. On page 3 of the specification, lines 8 to 10, it is stated that ``It deteriorates stability...results in a decrease in tensile strength. " has been corrected to "deteriorates the stability and causes deterioration of the quality of the plating film." 2. On page 4 of the specification, lines 18 to 20, [is the target accumulated ion...problems remain. ``Because the chemical copper plating solution has an alkaline pH of 11.5 or higher, the durability of the ion exchange membrane is poor, and copper precipitates in the electrodialysis tank, leaving many practical problems. ”, he corrected himself. 3. In the second to fourth lines of page 5 of the specification, amend the statement ``Because it is a method of removal, it exists...'' to ``It is a method of removal.'' . 4. In the 15th line of No. 5rA of the specification, the phrase "Plating reaction is likely to occur" is corrected to "Reduction reaction is likely to occur." 5. On the 4th and 5th lines of page 8 of the specification, it says ``Weakly acidic cation exchange resin... Any cation exchange resin should be used.'' ``Weakly acidic cation exchange resin.'' Please use either of the above.” 6. On page 8, line 13 of the specification, the phrase "cobalt, zinc and other metals" is amended to read "cobalt and other metals." 7. At the end of No. 11 TA of the specification, there is a statement that "After the ion exchange resin is regenerated, from the copper salt storage tank 6," [After the ion exchange resin is regenerated, from the alkali storage tank 5 by pump P-6, e.g.
% strength soda solution is passed through the ion exchange tower 3 via valves 18 and 16 to convert the ion exchange resin into Na type. Next, pump P-8 sends pure water from the pure water tank to wash away excess sodium hydroxide, and then to the copper salt storage tank 6.
From,” he corrected. 8. In the 8th line of page 12 of the specification, the statement "80 g of copper ions in" is corrected to "approximately 809 copper ions in". 9. On page 13 of the specification, lines 8 and 9, it says, ``In other words, the composition Cu... EDTA ・2Na0.11 mol/1 (40 gil!
) and formalin 0.06 mol/1 (5 shuttles/β),
Correct with pl-112, IJ. 10. On page 13, line 16 and $17 of the specification, “C
u O, 1 mol/11 pH 7...Ion is 0.0
It increased by 6 mol/β. It says "l"' Cu O, 1
mol/n(6,32#), pH is 7, copper ion is 0
,06 mol/1 (3, Fht/β) increased. ” he corrected. 11. rEDTA ・2N on page 14, line 14 of the specification
a0.11 mol/β, 37% hol"
・2NaO, 11 mol/1 (40 g/l), 37%
"Hor," he corrected. 12, 1-PEG well 100 on page 14, line 16 of the specification
0 2011j! #! J and aruwo l'-PEC4100
Corrected to 015 hit/IJ. 13. In the second line of page 15 of the specification, “The amount of saw ions is 0.
．． 03 mol/1" is replaced by "The amount of copper ion is 0.0
Corrected to 3 mol/l (1,9y#lito). 14. 10.080 mol/l on page 15, line 5 of the specification
"l'-0,080 mol/l (5
, 1g/j.'' 15. On page 15, line 9 of the specification, it says "Chemical copper plating with 0.04 mol of copper ions/p". Attachment 2, Claims (1) A chemical plating solution, at least a part of which is a metal type for plating, or at least a kind of cation exchange resin or at least a part thereof. Chemical plating characterized by replenishing plating metal ions to a chemical plating solution by treating with at least one kind of 431 fat or a mixture thereof, in which plating metal ions are coordinated or adsorbed. A method of replenishing metal ions into a liquid. (2) At least one type of cation exchange resin, at least a part of which is of a metal type for plating, or at least one type of chelate resin, at least a part of which has metal ions for plating coordinated or adsorbed; An apparatus for replenishing metal ions into a chemical plating solution, which is filled with a mixture of these, and is equipped with a chemical plating solution inlet and an ion exchange device that increases the metal ion concentration of the chemical plating solution. .

Claims (1)

[Claims] 1. A chemical plating solution is prepared by using at least one type of cation exchange resin, at least a part of which is of a metal type for plating, or at least a part of which has metal ions for plating coordinated or adsorbed. 0
A method for replenishing metal ions to a chemical plating solution, characterized in that metal ions for plating are supplied to the chemical plating solution by treating the chemical plating solution with at least one kind of chelate resin or a mixture thereof. 2. At least one cation exchange resin, at least a part of which is in the form of a metal for plating, or at least one chelate resin, at least a part of which has metal ions for plating coordinated or absorbed. replenishes metal ions to a chemical plating solution, which is characterized in that it is equipped with an ion exchange tank having a chemical plating solution acid population and an eluent outlet in which the concentration of metal ions in the chemical plating solution is increased. Or a dense transfer device.