A method for recovering water and copper from a copper chemical mechanical polishing waste stream

Abstract

A method for recovering water and copper from a copper chemical mechanical polishing (Cu-CMP) waste stream is disclosed. Water in the waste stream is recovered by distillation and copper is recovered by sulfuric acid treatment of sintered solids. The method provides at least 80% water recovery and at least 80% copper recovery.

Description

Technical Field

[0001] This invention relates to a method for recovering water and copper from waste streams of copper chemical mechanical polishing. Background Technology

[0002] Chemical mechanical polishing (CMP) has become a key technology in semiconductor integrated circuit manufacturing. Recently, CMP has also been introduced into multilayer printed circuit board (PCB) manufacturing processes. CMP uses abrasive and chemically etchable pastes to create a flat surface on the substrate. Depending on the substrate to be polished, appropriate abrasive pastes and polishing pads can be selected. CMP has been widely used on various substrates, including copper, tungsten, and polysilicon. Therefore, Cu-CMP indicates that the CMP process is applied to a substrate containing copper circuitry.

[0003] The waste stream generated by the Cu-CMP process contains abrasive particles, dissolved copper ions, oxidants (e.g., hydrogen peroxide), and organic matter, including surfactants, chelating agents, stabilizers, and dispersants. Cu-CMP wastewater from semiconductor manufacturing processes typically has a Cu ion concentration of less than 100 ppm; Cu-CMP wastewater from PCB manufacturing processes has a Cu ion concentration ranging from 100 ppm to 5,000 ppm. Environmental regulations require that CMP waste streams be treated before discharge to reduce the copper concentration in the wastewater to discharge targets, typically less than 0.5 ppm. Various treatment methods have been developed to remove harmful components from the waste streams. A treatment method that allows for the recycling of materials contained in the waste stream is particularly valuable because it contributes to environmental sustainability.

[0004] US Patent 6,398,964 discloses a method for treating wastewater from copper plating, copper cleaning streams, and Cu-CMP processes. The process involves first combining copper plating wastewater and waste liquid from the Cu-CMP process, adding a flocculant or coagulant to form larger solid particles, and then separating the solids and liquid by filtration to obtain a copper-containing liquid. Copper ions in this copper-containing liquid are then recovered by electrolytic deposition. This method can produce harmless sludge by removing copper. However, this method is not suitable for treating Cu-CMP waste streams alone because the copper concentration in the waste stream is too low, resulting in inefficient electrolytic deposition. Another disadvantage of this method is the need to add large amounts of flocculant or coagulant to the waste stream, leading to the introduction of more new organic pollutants.

[0005] PCT patent application publication WO2021 / 207298 discloses a system and method for treating a Cu-CMP waste stream using ultrafiltration and ion exchange. The method involves first passing the waste stream through an ultrafiltration unit to separate the abrasive particles from the copper-containing waste liquid; then using an ion exchange unit to remove dissolved copper, thereby reducing the copper concentration in the treated wastewater to a discharge target. However, due to the presence of residual hydrogen peroxide in the waste stream, the ultrafiltration membrane used in the system undergoes oxidative degradation and damage. Furthermore, the small abrasive particles easily clog the flow channels in the ultrafiltration unit, resulting in low filtration efficiency.

[0006] US Patent Application Publication US2011 / 0070811 discloses a method and apparatus for recycling CMP waste streams. This invention employs methods such as depth filtration, centrifugation, microfiltration, nanofiltration, and ultrafiltration, alone or in combination, to obtain reusable polishing slurry and recyclable water. However, the concentration, particle size, and uniformity of the abrasive particles in the polishing slurry are known to be key factors affecting the removal rate and defect control in CMP processes. Although the method disclosed in the aforementioned patent application is interesting and novel, its practical feasibility is not high. This is because the recovered abrasive particles may have been broken or agglomerated during the first polishing process, making it difficult to achieve the expected removal rate and stable defect control with a polishing slurry containing recovered abrasive particles.

[0007] The present invention therefore aims to provide a simple method for recovering water and copper from Cu-CMP waste streams, which overcomes the complex processes employed in the prior art and avoids various technical defects associated with related processes. The copper-containing solution recovered from the method of the present invention can be directly used as an electroplating solution in PCB electroplating processes, while the recovered water can be directly used for cleaning. Summary of the Invention

[0008] This invention provides a method for recovering water and copper from a waste stream of copper chemical mechanical polishing (Cu-CMP), comprising the following steps:

[0009] (a) Provide a waste stream for Cu-CMP;

[0010] (b) Remove most of the water from the waste stream of step (a) by distillation to obtain sludge and distilled water;

[0011] (c) Dry the sludge obtained from step (b) by hot air drying or spray drying;

[0012] (d) The dried sludge obtained in step (c) is sintered at a temperature of about 400°C to about 800°C for about 40 minutes to about 240 minutes to remove organic matter and obtain sintered solid.

[0013] (e) Treat the sintered solid obtained from step (d) with an aqueous sulfuric acid solution to form a mixture containing a copper sulfate solution and an insoluble solid;

[0014] (f) Separating the copper sulfate solution and the insoluble solid obtained from step (e) by centrifugation, filtration, or both; and

[0015] (g) The separated copper sulfate solution is recovered for recycling; wherein,

[0016] The waste stream of the Cu-CMP includes grinding particles, copper ions, and organic matter.

[0017] According to one embodiment of the method of the present invention, the copper ion concentration of the waste stream of Cu-CMP is between about 100 ppm and about 5000 ppm.

[0018] According to one embodiment of the method of the present invention, the waste stream of the Cu-CMP further comprises non-copper metal ions, and the concentration of each non-copper metal ion is in the range of 100 ppm or less, wherein the non-copper metal ions are selected from one or more of the group consisting of Ca, Cd, Co, Cr, Fe, Mg, Ni, Pb, Ti and Zn.

[0019] According to one embodiment of the method of the present invention, the distillation in step (b) is carried out under reduced pressure of 1 kPa to 50 kPa.

[0020] According to one embodiment of the method of the present invention, the distilled water obtained from step (b) contains copper ions at a concentration of less than 10 ppm and organic matter with a total organic carbon content (TOC) of less than 200 ppm.

[0021] According to one embodiment of the method of the present invention, the drying method in step (c) is hot air drying, which includes i) placing the sludge obtained from step (b) in an oven or heating chamber at a temperature of 45°C to 200°C, and ii) blowing hot air through the sludge at a flow rate of about 50 L / min to about 500 L / min for a duration of about 40 minutes to about 240 minutes.

[0022] According to one embodiment of the method of the present invention, the dried sludge obtained from step (c) contains, based on its total weight, about 80% or more of silica, about 5% to about 10% of copper, and about 0.001% to about 0.01% of titanium.

[0023] According to one embodiment of the method of the present invention, the concentration of the sulfuric acid aqueous solution in step (e) is about 1 to 9 mol / L, and the amount of the sulfuric acid aqueous solution added is 1 mL to 10 mL / 1 gram of sintered solid.

[0024] According to one embodiment of the method of the present invention, the separation method of step (f) is centrifugation at a speed of at least 500 rpm for a duration of about 1 minute to about 30 minutes.

[0025] According to one embodiment of the method of the present invention, the copper sulfate solution recovered in step (g) has a copper ion concentration of about 1,000 ppm to about 50,000 ppm.

[0026] According to one embodiment of the method of the present invention, the water recovery rate is 80% or greater based on the total volume of the waste stream of the Cu-CMP.

[0027] According to one embodiment of the method of the present invention, the total copper content of the waste stream from the copper chemical mechanical polishing in step (a) is 80% or greater.

[0028] According to one embodiment of the method of the present invention, the recovered copper sulfate solution is recycled in the copper electroplating process.

[0029] The present invention also provides a method for manufacturing a printed circuit board, comprising a copper electroplating process using an electroplating solution containing a copper sulfate solution recovered by the method of the present invention. Attached Figure Description

[0030] Figure 1 The diagram shown is a schematic flowchart of the method according to the present invention. Invention Details

[0032] All publications, patent applications, patents, and other references mentioned in this application are expressly incorporated herein by reference for all purposes, as if fully set forth herein. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In case of any conflict, this specification (including definitions) shall prevail.

[0033] When quantities, concentrations, or other values ​​or parameters are given as a list of ranges, preferred ranges, or preferred upper and lower limits, this should be understood as explicitly disclosing all ranges formed by any group of values ​​consisting of any upper or preferred value and any lower or preferred value, whether or not the range is disclosed individually. For example, when a range of “1 to 5” is described, the described range should be interpreted as including ranges “1 to 4,” “1 to 3,” “1–2,” “1–2 and 4–5,” “1–3 and 5,” etc. Unless otherwise stated, when numerical ranges are described herein, the range is intended to include its endpoints as well as all integers and fractions within that range.

[0034] When the term “about” is used to describe a range of values ​​or endpoints, this disclosure should be understood to include the specific values ​​or endpoints mentioned.

[0035] Furthermore, unless otherwise explicitly stated, "or" refers to an inclusive "or," not an exclusive "or." For example, condition A "or" B is satisfied by any of the following: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); and both A and B are true (or exist).

[0036] As used herein, the terms “an” and “a” include the concepts of “at least one” and “one or more”.

[0037] Unless otherwise specified, all concentrations in this document are calculated by weight of the component per unit volume, in mg / L or ppm, and the two can be used interchangeably.

[0038] The purpose of this invention is to provide a material recycling method that recovers copper from waste streams into the copper electroplating process without requiring further purification of the recovered copper sulfate solution. Furthermore, another objective of this invention is to recover water for cleaning purposes.

[0039] This invention provides a method for recovering water and copper from a waste stream of copper chemical mechanical polishing (Cu-CMP), comprising the following steps:

[0040] (a) Provide a waste stream for Cu-CMP;

[0041] (b) Remove most of the water from the waste stream of step (a) by distillation to obtain sludge and distilled water;

[0042] (c) Dry the sludge obtained from step (b) by hot air drying or spray drying;

[0043] (d) The dried sludge obtained in step (c) is sintered at a temperature of about 400°C to about 800°C for about 40 minutes to about 240 minutes to remove organic matter and obtain sintered solid.

[0044] (e) Treat the sintered solid obtained from step (d) with an aqueous sulfuric acid solution to form a mixture containing a copper sulfate solution and an insoluble solid;

[0045] (f) Separating the copper sulfate solution and the insoluble solid obtained from step (e) by centrifugation, filtration, or both; and

[0046] (g) The separated copper sulfate solution is recovered for recycling.

[0047] In this invention, the waste stream from Cu-CMP is typically a waste stream containing abrasive particles (e.g., silica particles), copper ions, oxidant (H2O2), and organic matter; the organic matter typically includes surfactants, chelating agents, stabilizers, and dispersants. While the organic matter can stabilize suspended particles in the chemical mechanical polishing slurry, its presence also makes solid-liquid separation of the waste stream difficult.

[0048] The pH value of the Cu-CMP waste stream is generally between 8 and 10, and the contents of various components are typically shown in Table 1 below:

[0049] Table 1. Components and their contents in Cu-CMP waste stream

[0050]

[0051] Distillation steps

[0052] Because the copper ion concentration in Cu-CMP waste streams is too low, typically only 100 ppm to 5,000 ppm, it is usually impossible to recover it effectively directly. In the method of this application, for the Cu-CMP waste stream, the first step of treatment is to distill off most of the water in the waste stream and collect its distillate, i.e., distilled water; this also increases the copper ion concentration in the original waste sludge.

[0053] Various commercial distillation apparatuses can be used in the method of this application, such as rotary evaporators, vacuum distillation evaporators, vapor recompression evaporators, etc.

[0054] In a preferred embodiment of the invention, the distillation apparatus is a rotary evaporator. Using a rotary evaporator under reduced pressure and increased temperature, the moisture contained in the waste stream can be easily evaporated. The distillation is typically carried out under reduced pressure of 1 kPa to 50 kPa.

[0055] The distilled water was then collected and subjected to elemental analysis. Typical impurities and their contents are shown in Table 2. The analytical methods used are well known to those skilled in the art.

[0056] Table 2. Typical impurities in distilled water and their content

[0057] Total organic carbon (TOC) copper ions ppm ≤200 ≤10

[0058] As can be seen from the values ​​in Table 2, the distilled water collected using the method of the present invention is pure enough to be recycled and used directly in the cleaning steps of the PCB manufacturing process.

[0059] Since most of the water in the waste stream is evaporated during the distillation step, the resulting sludge contains a variety of inorganic substances, organic substances, and a small amount of water.

[0060] Drying steps

[0061] The drying step involves further drying the sludge obtained from the distillation step.

[0062] There are no particular limitations on the drying steps, and any drying method known to those skilled in the art can be used.

[0063] Examples of the drying methods include, but are not limited to, hot air drying, spray drying, atmospheric pressure drying, vacuum drying, and freeze drying. The specific drying method can be selected by those skilled in the art based on the amount of sludge to be dried.

[0064] In one embodiment of the invention, the drying step employs hot air drying in an oven.

[0065] When using hot air drying, the temperature of the hot air can be from 45°C to 200°C, and the drying time can be from about 40 minutes to about 240 minutes. A preferred hot air temperature is from 60°C to 180°C, and the drying time is from about 60 minutes to about 180 minutes. A more preferred hot air temperature is 120°C, and the drying time is about 120 minutes.

[0066] Hot air can be blown through the sludge obtained after the distillation step at a flow rate of about 50 L / min to about 500 L / min; the preferred hot air flow rate is about 100 L / min to about 400 L / min; the more preferred hot air flow rate is about 200 L / min to about 300 L / min.

[0067] After drying, the water content in the sludge obtained in the original distillation step is further reduced, thereby obtaining a dried solid, and its typical components and contents are shown in Table 3.

[0068] Table 3. Typical components and contents of dried sludge

[0069] Element silicon dioxide Cu Ti organic matter weight% Approximately 80-90 Approximately 5 to 10 0.001～0.01 margin

[0070] Sintering steps

[0071] Since the sludge obtained after the drying step contains a large amount of organic matter, in order to remove the organic matter, the method of the present invention employs a sintering step to further perform high-temperature sintering treatment on the dried sludge.

[0072] The sintering process primarily involves treating the dried sludge at a sufficiently high temperature for a sufficiently long time to oxidize and decompose the organic matter within it. Simultaneously, due to the high-temperature environment during sintering, the silica hydrates and copper hydroxides in the dried sludge are also dehydrated and decomposed, resulting in powdery particles mainly composed of silica and copper oxide.

[0073] There are no particular restrictions on the equipment used in the sintering step, as long as it meets the essential requirements of sintering.

[0074] The sintering process can typically employ a muffle furnace or other industrial-grade sintering equipment, such as a chain sintering furnace or a conveyor belt sintering furnace. When using a muffle furnace as the sintering equipment, the sintering conditions can be, for example, a temperature set in the range of about 400°C to about 1000°C, preferably in the range of about 600°C to about 800°C; the sintering time can be about 1 hour to about 10 hours, preferably about 2 hours to about 8 hours, more preferably about 3 hours to about 6 hours.

[0075] During the sintering process, the resulting solid loses its organic matter. For example, depending on the organic matter content of the original dried sludge, the sintered solid obtained by sintering will lose approximately 10% to 60% of its weight, or approximately 20% to 50% of its weight.

[0076] Sulfuric acid treatment steps

[0077] After the sintering steps described above, the resulting sintered solid is subjected to acid treatment to dissolve the copper oxide. During this acid treatment, the copper oxide in the powder particles obtained from the sintering step reacts with the acid to form a copper salt solution; silicon dioxide, however, does not react with the acid.

[0078] The acid selected must be capable of readily dissolving copper oxide to obtain a copper-containing solution; and preferably, the resulting copper-containing solution can be easily recycled. The acid can be sulfuric acid, nitric acid, or hydrochloric acid, etc.; considering the recyclability of the copper-containing solution, sulfuric acid is preferred.

[0079] In one exemplary embodiment, the acid is sulfuric acid, and the specific chemical reaction that occurs is as follows:

[0080] CuO + H₂SO₄ = CuSO₄ + H₂O.

[0081] In other words, when sulfuric acid is used as the acid treatment step for copper oxide, the resulting copper-containing solution is a copper sulfate solution. This copper sulfate solution can be conveniently used in subsequent copper electroplating processes.

[0082] When the acid is sulfuric acid, the acid solution is an aqueous solution of sulfuric acid with a concentration of about 1 to 9 mol / L, preferably about 2 to 8 mol / L, and more preferably about 3 to 7 mol / L.

[0083] The amount of sulfuric acid aqueous solution added is 1 mL to 10 mL / 1 gram of sintered solid.

[0084] Treatment with an aqueous sulfuric acid solution yields a mixture containing a copper sulfate solution and an insoluble solid, primarily silicon dioxide.

[0085] Because organic matter has been completely removed and silica is insoluble in sulfuric acid, the main metallic component of the copper sulfate solution is copper ions. In addition, the copper sulfate solution also contains small amounts of non-copper metallic impurities derived from chemical mechanical polishing slurries, including but not limited to Ca, Cd, Co, Cr, Fe, Mg, Ni, Pb, Ti, Zn, or combinations thereof.

[0086] Separation steps

[0087] To separate the copper sulfate solution and insoluble solids from a mixture treated with sulfuric acid, the mixture is usually subjected to centrifugation, filtration, or a combination of both.

[0088] There are no particular restrictions on the specific centrifugation and / or filtration operations, which can be selected by those skilled in the art based on the condition of the resulting mixture.

[0089] There are no particular restrictions on centrifugation operations; any centrifuge equipment that meets the required rotational speed can be used. Examples of centrifuge equipment include filter centrifuges and lift centrifuges.

[0090] When a centrifuge is used for separation, the centrifuge speed can typically be greater than 500 rpm; or in the range of 1,000 rpm to 10,000 rpm; or in the range of 2,000 rpm to 8,000 rpm.

[0091] There are no particular restrictions on filtration operations. In terms of industrial operability, filter presses, vacuum filters, gravity filters, etc., can be used.

[0092] The method of the present invention includes the processing steps described above, and may also include, for example: Figure 1 As shown, the recovered distilled water and copper sulfate solution are used in a recycling process step.

[0093] It is noteworthy that the copper sulfate solution obtained by the method of this invention has a very high purity, specifically, a purity higher than that required for copper electroplating processes. Therefore, the copper sulfate solution can be used to replenish fresh copper sulfate solution in copper electroplating processes, and / or to prepare the Virgin Make-up Solution (VMS) for copper electroplating tanks. The VMS contains water, sulfuric acid, copper sulfate, and a small amount of hydrochloric acid.

[0094] Many aspects and embodiments of the invention have been described above, but these descriptions are exemplary and not restrictive. After reading this specification, those skilled in the art will understand that other aspects and implementations are possible without departing from the scope of the invention. Other features and advantages of the invention will become apparent from the following detailed description and claims. Detailed Implementation

[0095] Analytical methods

[0096] Total organic carbon (TOC) content: The total organic carbon content was measured by a TOC analyzer. Specifically, the TOC analyzer used in the method of this invention was a Mettler Toledo 5000TOCi.

[0097] The metal ion content was measured using an inductively coupled plasma optical emission spectrometer (ICP-OES). Specifically, the instrument used in the method of this invention is the PerkinElmer Optima model. TM 7000DV.

[0098] Waste flow sample

[0099] The specific sample was collected from waste streams of CMP processes performed on a substrate containing copper circuitry, and the applied polishing slurry was EX RDS-MK10-001. Testing revealed that the sample had a copper ion concentration of 2640 ppm and a pH of 8.7.

[0100] Example 1

[0101] A 1L sample of Cu-CMP waste stream was distilled using a rotary evaporator at 0.2 atm and 85°C to obtain sludge with most of the water removed and collected distilled water, yielding 0.86L of the sludge and distilled water. Analysis of the distilled water revealed a copper ion concentration of less than 0.1 ppm and a total organic carbon content of 94 ppm. The calculated water recovery rate was 86%.

[0102] The aforementioned sludge was placed in a hot air oven for drying; the oven temperature was set to 120°C, and the drying time was 2 hours. 53.02 g of the dried sludge was obtained. Analysis revealed that it contained approximately 90% silica, approximately 5% copper, approximately 0.005% titanium, and the remainder being organic matter.

[0103] The dried sludge was sintered in a muffle furnace at 500°C for 4 hours, yielding a sintered solid (30.90g) in powder form. A 1.00g sample was tested, revealing a copper content of 8.47%, meaning the total weight of copper in the 30.90g sintered solid was 2.617g.

[0104] Example 2

[0105] Take 10.00 g of the sintered powder obtained in Example 1, and add 50 mL of sulfuric acid (3.8 mol / L concentration) to the sintered powder. Stir thoroughly to ensure complete reaction with the sulfuric acid, forming a mixture containing copper sulfate solution and insoluble solids. Transfer the mixture to a centrifuge tube. After centrifugation at 5000 rpm for 5 minutes, collect 41 mL of the supernatant and analyze the content of various elements.

[0106] Example 3

[0107] Take 10.00 g of the sintered powder obtained in Example 1 and treat it with sulfuric acid according to the following steps: Step 1: Add 20 mL of sulfuric acid (3.8 mol / L) to the sintered powder. Stir thoroughly to ensure complete reaction with the sulfuric acid. Transfer the resulting mixture to a centrifuge tube. Step 2: Centrifuge at 5000 rpm for 5 minutes and collect the supernatant. Step 3: Add 10 mL of sulfuric acid (3.8 mol / L) to the precipitate in the centrifuge tube and shake vigorously; centrifuge at 5000 rpm for 5 minutes and collect the supernatant. Step 4: Repeat Step 3 twice. Finally, mix the supernatants collected in Steps 2-4, totaling 43 mL, and analyze the content of various elements.

[0108] The supernatant obtained after centrifugation was collected, and the content of various elements in it was analyzed by ICP. The test results and the quality control specifications for typical copper sulfate solutions used in copper plating are shown in Tables 4 and 5 below.

[0109] The recovery rate of the method described in this invention can be calculated using the following formulas (1), (2), and (3), wherein, firstly, the copper recovery rate (A) from step (a) to step (d) is calculated using formula (1); then, the copper recovery rate (B) from step (e) to step (g) is calculated using formula (2). Finally, the copper recovery rate of the method described in this invention is calculated using formula (3).

[0110] Copper recovery rate (A) = Total copper in sintered powder / Total copper in waste stream — Formula (1)

[0111] Wherein, the total copper content of the waste stream = Cu ion concentration of the waste stream in Cu-CMP × volume of the waste stream;

[0112] Copper recovery rate (B) = Copper content of supernatant / Copper content of sample — Formula (2)

[0113] Wherein, the copper content of the supernatant = the Cu ion concentration of the supernatant × the volume of the supernatant;

[0114] The copper recovery rate of this method = copper recovery rate (A) × copper recovery rate (B) — formula (3)

[0115] Table 4: Water and copper recovery rates of the method of the present invention

[0116]

[0117] Table 5: Analysis results of non-copper metal elements

[0118] Non-copper metal concentration (ppm) Example 1 Example 2 Electroplating solution specifications Cd <1 <1 ≤2 Cr 1.74 1.76 <7 Fe 9.26 9.66 ≤20 Mg 3.43 2.30 - Ni 1.16 1.30 ≤15 Pb - - ≤20 Pd <1 <1 - Ti <1 1.59 - Zn 3.82 3.84 ≤30

[0119] The results in Table 4 indicate that the distilled water collected in Example 1 is sufficiently pure to be recycled and used directly in the cleaning steps associated with the copper electroplating process.

[0120] Furthermore, the method of the present invention can also recover most of the copper from the original Cu-CMP waste stream. A comparison of copper recovery rates between Examples 2 and 3 shows that in Example 3, batch treatment with sulfuric acid solution in the same total amount easily improved the copper recovery rate (from 84% to 97%).

[0121] Furthermore, the results in Table 5 show that the non-copper metal elements contained in the recovered copper sulfate solution are all within the typical quality specifications for electroplating solutions. Therefore, the recovered copper sulfate solution can be used as a supplementary electroplating solution without causing any negative impact.

[0122] In summary, it can be seen that the method according to the present invention is very suitable for recovering water and copper from Cu-CMP waste streams, and the recovered copper and water are suitable for recycling.

Claims

1. A method for recovering water and copper from a copper chemical mechanical polishing waste stream, comprising the following steps: (a) Providing a waste stream for copper chemical mechanical polishing; (b) Remove most of the water from the waste stream of step (a) by distillation to obtain sludge and distilled water; (c) Dry the sludge obtained from step (b) by hot air drying or spray drying; (d) The dried sludge obtained in step (c) is sintered at a temperature of 400°C to 1000°C for 1 to 10 hours to remove organic matter and obtain sintered solid. (e) Treat the sintered solid obtained from step (d) with an aqueous sulfuric acid solution to form a mixture containing a copper sulfate solution and an insoluble solid; (f) Separating the copper sulfate solution and the insoluble solid obtained from step (e) by centrifugation, filtration, or both; and (g) The separated copper sulfate solution is recovered for recycling; in, The waste stream from the copper chemical mechanical polishing includes abrasive particles, copper ions, and organic matter.

2. The method according to claim 1, wherein the copper ion concentration of the waste stream from the copper chemical mechanical polishing is between 100 ppm and 5000 ppm.

3. The method according to claim 1, wherein the waste stream from the copper chemical mechanical polishing further comprises non-copper metal ions, and the concentration of each non-copper metal ion is in the range of 100 ppm or less, wherein the non-copper metal ions are selected from one or more of the group consisting of Ca, Cd, Co, Cr, Fe, Mg, Ni, Pb, Ti and Zn.

4. The method according to claim 1, wherein the distillation in step (b) is carried out under reduced pressure of 1 kPa to 50 kPa.

5. The method according to claim 1, wherein the distilled water obtained from step (b) contains copper ions at a concentration of less than 10 ppm and organic matter with a total organic carbon content of less than 200 ppm.

6. The method according to claim 1, wherein the drying method in step (c) is hot air drying, comprising i) placing the sludge obtained in step (b) in an oven or heating chamber at a temperature of 45°C to 200°C, and ii) blowing hot air through the sludge at a flow rate of 50 L / min to 500 L / min for a duration of 40 minutes to 240 minutes.

7. The method of claim 1, wherein the dried sludge obtained from step (c) contains, based on its total weight, 80% or more silica, 5% to 10% copper, and 0.001% to 0.01% titanium.

8. The method according to claim 1, wherein the concentration of the sulfuric acid aqueous solution in step (e) is 1 to 9 mol / L, and the amount of the sulfuric acid aqueous solution added is 1 mL to 10 mL / 1 gram of sintered solid.

9. The method according to claim 1, wherein the separation method in step (f) is centrifugation at a speed of at least 500 rpm for a duration of 1 minute to 30 minutes.

10. The method of claim 1, wherein the copper sulfate solution recovered in step (g) has a copper ion concentration of 1,000 ppm to 50,000 ppm.

11. The method of claim 1, wherein, based on the total volume of the waste stream from the copper chemical mechanical polishing in step (a), the water recovery rate is 80% or greater.

12. The method of claim 1, wherein the total copper content of the waste stream from the copper chemical mechanical polishing in step (a) is 80% or greater, and the copper recovery rate is 80% or greater.

13. The method according to claim 1, wherein the copper sulfate solution recovered in step (g) is recycled in the copper electroplating process.

14. A method of manufacturing a printed circuit board, comprising a copper electroplating process using an electroplating solution containing a copper sulfate solution recovered by the method of claim 1.

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