JP2927352B1 - Etching waste liquid recycling method and its apparatus - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To completely recover a copper chloride etching waste liquid generated in an etching tank and to perform a regenerating reaction, and then supply the waste liquid to a plating operation again, thereby reducing raw material costs and reducing environmental pollution pollution problems. Provided is a waste liquid recycling method and a device therefor. SOLUTION: The etching waste liquid recycling method of the present invention recovers a copper chloride waste liquid generated in an etching tank,
After going through the synthesis step, the thermal decomposition step, the dehydration step, and the dissociation step, it is further sent to the electroplating step to perform electroplating, thereby recycling the copper chloride waste liquid generated in the etching tank and preventing pollution problems of environmental protection. At the same time, raw material costs can be reduced. The apparatus employed in the above method includes a recovery unit for recovering copper chloride waste liquid, a raw material supply unit for supplying a reaction raw material, a reaction unit for performing a reaction, and a dehydration unit for dehydrating a reaction product. It comprises a dissociation unit for dissociating and producing an electrolytic solution, and an electroplating unit for performing electroplating using the obtained electrolytic solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an etching waste liquid recycling method and an apparatus therefor, and more particularly to a method for completely recovering copper chloride etching waste liquid generated in an etching tank, regenerating it, supplying it again to a plating operation, and reducing the raw material cost. The present invention relates to an etching waste liquid recycling method and an apparatus thereof that can reduce pollution and environmental pollution problems.

[0002]

2. Description of the Related Art Printed circuit boards (PCBs) and the like have already become indispensable components of high-precision electronic products. After the metal film is coated by electroplating, based on the layout of the electric circuit, unnecessary portions other than the electric circuit on the substrate provided with the copper metal coating film are removed by etching using a photoengraving technique, and the copper printed on the substrate. Form a circuit.

[0003] The above-mentioned conventional etching operation uses copper chloride (C
The etching is performed by using uCl ₂ ), and the copper metal in the portion of the substrate surface to be etched is oxidized and removed using copper chloride as an oxidizing agent, and the reaction formula is as follows. Cu + CuCl ₂ → 2CuCl Then, the cuprous chloride (Cu
Cl) to solve the reaction products
l) and hydrogen peroxide (H ₂ O ₂ ) are added to cause an oxidation-reduction reaction, and the cuprous chloride is oxidized to copper oxide for continuous use. The oxidation-reduction reaction formula is as follows: It is on the street.

2CuCl + 2HCl + H ₂ O ₂ → 2Cu
Cl ₂ + 2H ₂ O However, the above etching reaction is carried out for a certain time,
When the concentration of Cu ²⁺ increases and reaches 50 g / 1, the etching effect is gradually weakened, the required time for etching is prolonged, and the production efficiency is significantly affected. Conventionally, copper chloride etching waste liquid is recovered to produce copper sulfate and used as a herbicide. However, since the unit price of this kind of herbicide is too low, it is not economically viable. In addition, there are those who intend to introduce the copper sulfate into the plating tank and use it as a supplementary material for copper ions (Cu ²⁺ ).
Since O ²⁻ and H ₂ O gradually increase with the reaction time, there is a problem that imbalance occurs in the electrolytic solution. The reaction formula is as follows.

[0005] _{CuSO 4 · 5H 2 O → Cu} 2+ + SO 4 2-
+ 5H ₂ O

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned various technical obstacles that occur during the processing of the conventional etching waste liquid and the environmental pollution problem that arises jointly, the first object of the present invention is to provide an etching tank for an etching tank. An object of the present invention is to provide an etching waste liquid recycling method capable of reducing the cost of raw materials and reducing the pollution problem of environmental preservation by completely recovering the copper chloride etching waste liquid and causing it to undergo a regeneration reaction, and then supplying it to the plating operation again to reduce the cost of raw materials. .

A second object of the present invention is to provide the above-mentioned present invention, which exhibits a high etching waste liquid recovery function, can sufficiently reduce environmental protection pollution problems, and can be expected to reduce raw material costs. An object of the present invention is to provide an apparatus which can be used in an etching waste liquid recycling method.

[0008]

In order to achieve the above object, an etching waste liquid recycling method according to the present invention comprises a recovery step of recovering copper chloride etching waste liquid generated in an etching tank, and adding sodium hydroxide to the recovery step. Reacting with the waste copper chloride etching waste liquid to produce copper hydroxide, and a thermal process for thermally decomposing the copper hydroxide product produced in the above-mentioned synthesis step at a temperature of 80 ° C. or more to produce solid copper oxide. Decomposition step, dehydration of the solid copper oxide obtained in the thermal decomposition step, dehydration step to obtain a dried copper oxide solid, the dried copper oxide solid obtained in the dehydration step, dissolved by sulfuric acid A dissociation step of forming a copper ion-containing electrolyte, and electroplating by transporting the copper ion-containing electrolyte produced in the dissociation step into a plating tank. Configured to include a gas-plating step.

On the other hand, the etching waste liquid recycling apparatus of the present invention comprises a recovery unit for recovering copper chloride etching waste liquid, a raw material supply unit for supplying sodium hydroxide to a recycling reaction, a copper chloride etching waste liquid from the recovery unit, and A reaction unit that receives sodium hydroxide from the raw material supply unit and performs a recycling reaction, generates and sends out hydrous copper oxide, and a dehydration unit that dehydrates the hydrous copper oxide generated in the above reaction unit and sends out dried copper oxide. A storage space for accommodating the dried copper oxide sent out by the dehydration unit, partitioning the interior of the storage space into a plurality of dissociation chambers that circulate through a partition plate, and supplying a sulfuric acid solution to the dried copper oxide; Dissociation unit to dissociate copper sulfate electrolyte, electrolyte inlet and electroplating A liquid outlet is provided, and the copper sulfate electrolytic solution obtained by dissociation in the dissociation unit is fed into the electrolytic solution inlet to perform electroplating, and the sulfuric acid residual solution after electroplating is discharged from the electroplating residual liquid outlet. And a plating unit.

[0010] Then, regarding the above method and its apparatus,
It is even more preferable that a great deal of skill be devised in each detail and appropriate steps or members be added so as to further improve the operation and effect. According to the method and the apparatus of the present invention configured as described above, the copper chloride etching waste liquid generated in the etching tank is recovered, and after performing various reactions in the reaction unit to generate solid copper oxide, Since the dissociation unit builds up the electrolyte solution required by the electroplating unit, there is no need to release the copper chloride etching waste solution generated in the etching tank, and the entire solution can be recovered and reused.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described based on embodiments, but the present invention is not limited to these embodiments. First, as shown in FIG. 1, the etching waste liquid recycling method and apparatus of the present invention mainly include the following steps.

A) Recovery Step That is, it refers to recovering the copper chloride etching waste liquid generated in the etching tank 1. Generally, during the etching process,
After the copper chloride (CuCl ₂ ) undergoes an oxidation-reduction reaction with copper, the subsequent treatment is further performed using hydrochloric acid (HCl) and hydrogen peroxide (H ₂ O ₂ ), and the reaction formula is as follows. is there.

Cu + CuCl ₂ → 2CuCl 2CuCl + 2HCl + H ₂ O ₂ → 2CuCl ₂ + 2H
₂ O Then, if the etching treatment is performed for a certain period of time, the concentration of copper ions (Cu ²⁺ ) in the copper chloride etching waste liquid after the treatment gradually increases, so that the etching effect is weakened and it is no longer necessary in actual use. In the present invention, the copper chloride etching waste liquid is collected and recycled.

The recovery step of the present invention is to recover using a recovery unit, and the recovery unit is not particularly limited, as long as the copper chloride etching waste liquid in the etching tank 1 can be recovered. An exhaust pipe may be provided to lead out the copper chloride etching waste liquid in the etching tank 1. b) Synthesis step The above-mentioned recovered copper chloride etching waste liquid is stored in a waste liquid storage tank 3
Sodium hydroxide (NaOH) previously stored in the raw material supply tank 4 of the raw material supply unit.
And reacting them together in the reaction tank 5 of the reaction unit to produce a copper hydroxide product (Cu (OH) ₂ ). The reaction formula is as follows.

CuCl ₂ + 2NaOH → Cu (OH) ₂
+ 2NaCl c) pyrolysis step Subsequently, the resulting copper hydroxide product (Cu (O
H) ₂ ) is thermally decomposed by a heating method at a temperature of 80 ° C. or higher in the reaction tank 5 of the reaction unit. The reaction formula is as follows.

[0016] When the copper hydroxide is thermally decomposed, it is decomposed into solid copper oxide and deposited on the bottom of the reaction tank 5, whereby sodium chloride and water as by-products generated by the reaction in the reaction tank 5 are eliminated.

D) Dehydration Step Since the solid copper oxide deposited on the bottom of the reaction tank 5 is partially contaminated with moisture and sodium chloride, the copper oxide is taken out from the bottom of the reaction tank 5 and the dehydration unit 6 is removed. Dehydration and dechlorination with water. As the dehydration unit 6 employed in the present invention, a conventional general dehydration device such as a centrifugal device may be used, and a pure copper oxide solid dried through the dehydration unit 6 can be obtained.

E) Dissociation Step The dried copper oxide solid obtained by the dehydration unit 6 is sent to the dissociation unit 7 and dissolved and dissociated using sulfuric acid (H ₂ SO ₄ ) to perform copper sulfate (CuSO ₄ ) electrolysis. Make liquid. The reaction formula is as follows. CuO _(s) + H ₂ SO ₄ → CuSO ₄ + H ₂ O In the present invention, the dissociation unit 7 is replaced with the dehydration unit 6
And a storage space 71 for dried copper oxide taken out of the storage space 71. The interior of the storage space 71 is partitioned into a plurality of dissociation chambers whose upper and lower regions are interconnected by partitioning plates 72 and 73, and a sulfuric acid solution is supplied in the following electroplating unit. Then, the dissociation reaction of the copper oxide is performed.

F) Electroplating Step The copper sulfate electrolyte produced in the dissociation step is transported into the plating tank of the electroplating unit 8 for electroplating, and the etching waste liquid generated in the etching tank 1 of the present invention is recycled. Can be sufficiently achieved. Then, in the electroplating unit 8 according to the present invention, the electrolysis solution transported from the dissociation unit 7 and the plating waste solution (including sulfuric acid residual solution and low-concentration copper sulfate waste solution) generated after the electroplating treatment are combined. The electroplating unit 8 is provided with an electrolyte inlet and an electroplating residue outlet, and the copper sulfate electrolyte is transported to the electroplating unit 8 through the electrolyte inlet to perform electroplating. Further, a circulation pipe is further provided at the outlet of the electroplating residual liquid, and the sulfuric acid residual liquid generated after the electroplating is circulated to the dissociation unit 7 for reuse.

In order to improve the reaction efficiency by mixing the transported copper chloride and sodium hydroxide reactants more uniformly in the reaction tank 5, a stirring member is provided in the reaction tank 5, and the reaction in the tank is performed. The product may be sufficiently stirred to increase the contact area to improve the reaction efficiency. The stirring member referred to here is a mechanical stirrer generally used in the related art, for example, a double arm stirrer, a screw stirrer, or the like.

Since the copper chloride transported to the dissociation unit 7 is in the form of a solid, a pulverizing member 9 is added to the dehydration unit for accelerated dissolution, and the solid chloride previously formed in the dehydration unit 6 is solidified. Copper may be pulverized, and a conventional general polishing machine can be used as the pulverizing member 9. Further, in order to make the electrolytic solution sent into the electroplating unit 8 more pure, a purifying unit 10 is provided at an outlet of the dissociation unit 7 and the electrolytic solution is purified by a weak electrolytic purifying step of the purifying unit 10. For example, iron ions (Fe ⁺³ ) and zinc ions (Zn ⁺² ) contaminated in the liquid may be removed. The purifying unit 10 is provided with one or more electrodes 101 therein, performs weak electrolysis by a weak electrolysis method, and precipitates and removes non-copper ion metallic impurities. Electrodes.

Since the electrolyte solution produced by the dissociation unit 7 can be operated more smoothly by the whole system of the present invention, a transport member 11 may be provided between the dissociation unit 7 and the electroplating unit 8. The transport member 11 is formed by a pressurizing pump, and the external force is pressurized to ensure a smooth transport state of the electrolytic solution inside the system and maintain a smooth flow in the pipeline.

In addition, in order to further purify the electrolyte fed into the electroplating unit 8, a filter member 12 may be provided at the electrolyte inlet of the electroplating unit 8, and the filter member 12 may be provided with a filter. It is formed of a filter material or activated carbon having fine pores, whereby it is possible to remove impurities contaminated in the electrolytic solution one step further. As described above, the main source of the raw material in the dissociation unit 7 is the dehydration unit 6
Is an electroplating residual liquid circulated from the dried copper oxide and the electroplating unit 8 produced in the above step, and an outlet for the electroplating residual liquid in order to maintain the concentration of the produced electrolyte (copper sulfate concentration) at a predetermined standard A sensor 13 for detecting the concentration of copper ions contained in the circulating electroplating residual solution, and also providing a supply control member 14 at the front end (copper oxide inlet front end) of the dissociation unit 7. And the sensor 13 controls the supply amount of copper oxide to the dehydration unit 6 based on the value detected by the sensor 13. The sensor 1
Reference numeral 3 denotes a general concentration measurement analyzer, and the supply amount control member 14 is not particularly limited as long as it can adjust and control the flow rate.
For example, a conventional general-use automatic pulverizing feeder may be used.

The electrode employed in the electroplating unit 8 of the present invention has a cathode which can be electroplated by hanging a material to be plated directly on the electroplating unit 8 and an anode which is coated with titanium. Electroplating can be performed by presenting a porous flat plate made of the iridium oxide material described above as an insoluble anode made to have an outer shape matching the surface shape of the material to be plated. And, because of the precision of electroplating, the volume of the non-soluble anode itself is extremely small and does not change, so that the current distribution control of electroplating is relatively easy, and at the same time, the distance between the cathodes is shortened as much as possible. A uniform electroplating effect can be obtained. Generally, when a non-soluble anode is used, the distance between the cathodes is kept at a short distance within a range of 2 to 3 cm.

[0025]

According to the present invention formed as described above, the copper chloride etching waste liquid generated in the etching tank is recovered, subjected to various reactions in the above reaction unit to produce solid copper oxide, and further subjected to electroplating. Since the unit is made up with the required electrolyte, there is no need to release the copper chloride etching waste liquid generated in the etching tank, all of which can be recovered and reused, thus saving waste processing equipment costs and costs. In addition, it is possible to reduce the partial raw material cost of the electroplating and to exert an excellent effect on environmental protection.

[Brief description of the drawings]

FIG. 1 is a layout display diagram of a relatively preferred embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Etching tank 2 Waste liquid discharge pipe 3 Waste liquid storage tank 4 Raw material supply tank 5 Reaction tank 6 Dehydration unit 7 Dissociation unit 8 Electroplating unit 9 Crushing unit 10 Purification unit 11 Transport member 12 Filtration member 13 Sensor 14 Supply amount control member

Claims (27)

(57) [Claims] A collecting step of collecting a copper chloride etching waste liquid generated in an etching tank; a synthesizing step of adding sodium hydroxide to react with the collected copper chloride etching waste liquid to generate copper hydroxide; A pyrolysis step of pyrolyzing the copper hydroxide product generated in the step under a temperature of 80 ° C. or more to produce solid copper oxide; and dehydrating the solid copper oxide obtained in the pyrolysis step,
A dehydration step of obtaining a dried copper oxide solid; a dissociation step of dissolving the dried copper oxide solid obtained in the dehydration step with sulfuric acid to form a copper ion-containing electrolyte; and a copper produced in the dissociation step. An electroplating step of transporting the ion-containing electrolytic solution into the plating tank to perform electroplating; 2. The method according to claim 1, wherein the dehydrating step further includes a pulverizing step, wherein the dried copper oxide solid after dehydration is pulverized.
2. The etching waste liquid recycling method described in 1. 3. The etching waste liquid recycling method according to claim 1, wherein the dehydrating step further includes a flow rate control step, and controls an amount of the copper oxide supplied and pulverized in the dissociation step. 4. The etching waste liquid recycling method according to claim 1, wherein the dissociation step further includes a purification step, and other non-copper metal ions contained in the produced copper ion-containing electrolyte are removed by electrolytic deposition. 5. The etching waste liquid recycling method according to claim 4, wherein said purifying step removes non-copper metal ions by a weak electrolysis method. 6. The sulfuric acid used in the dissociation step,
The etching waste liquid recycling method according to claim 1, wherein the residual sulfuric acid liquid during the electroplating step is circulated and supplied. 7. The etching waste liquid recycling method according to claim 5, wherein the electrode in the weak electrolysis method in the purification step is formed of a titanium metal electrode. 8. The electroplating step further comprises: a) producing an insoluble anode member having an outer shape matching the surface shape of the material to be plated; and b) suspending the material to be plated on a cathode, and suspending the produced anode member. 2. The method of claim 1, further comprising the steps of: c) conducting electricity between the cathode and the anode to perform electroplating. 9. The etching waste liquid recycling method according to claim 8, wherein the insoluble anode member is formed of a titanium-coated iridium oxide material. 10. The method according to claim 8, wherein said insoluble anode member is formed of a porous flat plate. 11. An etching waste liquid recycling method according to claim 8, wherein the electroplating is performed while maintaining a distance between the insoluble anode member and the material to be plated at 2 to 3 cm. 12. A recovery unit for recovering a copper chloride etching waste liquid, a raw material supply unit for supplying sodium hydroxide to a recycling reaction, and a copper chloride etching waste liquid from the recovery unit and receiving sodium hydroxide from the raw material supply unit. A reaction unit that performs a recycle reaction to generate and send hydrous copper oxide, a dehydration unit that dehydrates the hydrous copper oxide generated in the reaction unit, and sends out dried copper oxide, and a dried copper oxide that is sent out by the dehydration unit Is provided, and the inside of the storage space is partitioned by a partition plate into a plurality of dissociation chambers that circulate with each other, and a sulfuric acid solution is supplied to dissociate the dried copper oxide to form a copper sulfate electrolyte. A dissociation unit to be formed, an electrolyte inlet and an electroplating residue outlet, and the dissociation from the electrolyte inlet. Performs electroplating by feeding copper sulfate electrolytic solution obtained by dissociation in knit, etching waste liquid recycling device comprising an electric plating unit for feeding the sulfuric acid remaining liquid after electroplating than the electrical plating residual liquid outlet, a. 13. A stirring member is provided in the reaction unit,
13. The etching waste liquid recycling apparatus according to claim 12, wherein the fed copper oxide and sodium hydroxide are sufficiently stirred to cause a uniform reaction. 14. The etching waste liquid recycling apparatus according to claim 12, wherein the dewatering unit is formed by a centrifugal or pressure filtration type dewatering member. 15. A purifying unit is provided at an outlet end of the dissociating unit, one or more electrodes are formed inside the purifying unit to perform weak electrolysis, and an electrolytic solution sent from the dissociating unit is discharged. 13. The etching waste liquid recycling apparatus according to claim 12, wherein the purification unit receives and purifies the etching waste liquid. 16. The etching waste liquid recycling apparatus according to claim 15, wherein the electrode used in the purifying unit is formed of a titanium metal electrode. 17. The etching waste liquid recycling apparatus according to claim 12, wherein a transporting member is provided at a front end of the electrolytic solution inlet of the electroplating unit to enhance feeding of the electrolytic solution to the electroplating unit. 18. The etching waste liquid recycling apparatus according to claim 17, wherein said transport member is formed by a pressure pump. 19. A filter member is provided between the electrolyte inlet of the electroplating unit and the purification unit,
13. The etching waste liquid recycling apparatus according to claim 12, wherein impurities are removed by filtration from the electrolyte during transportation. 20. The etching waste liquid recycling apparatus according to claim 19, wherein the filtering member is formed of a fine filtering material or activated carbon. 21. A circulating pipe is attached to the electroplating unit, one end of the circulating pipe is connected to the electroplating residual liquid outlet, and the other end is connected to the inside of the dissociation unit. 13. The etching waste liquid recycling apparatus according to claim 12, wherein the electroplating residual liquid is circulated to the dissociation unit. 22. A sensor is provided at the outlet of the electroplating residue to detect the concentration of copper ions contained in the outflowing electroplating residue, and a supply control member is also provided at the front end of the dissociation unit. 13. The etching waste liquid recycling apparatus according to claim 12, wherein the amount of copper oxide supplied to the dehydration unit is controlled based on a value detected by the sensor. 23. The etching waste liquid recycling apparatus according to claim 12, wherein a pulverizing member is provided between the dehydration unit and the dissociation unit to pulverize the copper oxide sent from the dehydration unit. 24. The electroplating unit according to claim 12, wherein the electroplating unit comprises a cathode on which the material to be plated is hung and a non-soluble anode which is a metal member whose external shape matches the surface shape of the material to be plated. Etching waste liquid recycling equipment. 25. The etching waste liquid recycling apparatus according to claim 24, wherein the insoluble anode is formed of a titanium-coated iridium oxide material. 26. The etching waste liquid recycling apparatus according to claim 24, wherein the insoluble anode is formed of a porous flat plate. 27. The etching waste liquid recycling apparatus according to claim 24, wherein the electroplating is performed while maintaining the distance between the insoluble anode member and the material to be plated at 2 to 3 cm.