A device and method for preparing a copper sulfate plating solution for chip packaging

Abstract

The application discloses a kind of copper sulfate electroplating solution preparation device and method for chip packaging, it is related to chip packaging technical field, and its technical solution points are as follows: including copper sulfate pentahydrate storage tank, negative pressure feeder, feed volume bin, electronic scale, copper sulfate solution preparation tank, preparation pump one, micropore filter one, resin barrel, electroplating solution preparation tank, spiral spray head, preparation pump two, heat exchanger, micropore filter two;Copper sulfate pentahydrate storage tank is connected by negative pressure feeder, feed volume bin, electronic scale and copper sulfate solution preparation tank;Copper sulfate solution preparation tank is communicated with electroplating solution preparation tank by micropore filter one and resin barrel, and copper sulfate solution is added into electroplating solution preparation tank by preparation pump one after preparation in copper sulfate solution preparation tank;Electroplating solution preparation tank and preparation pump two, heat exchanger form circulating system, and micropore filter two is used to fill electroplating solution.The whole preparation device of the application adopts automatic instrument and logic control, and full-process can realize automatic and intelligent operation.

Description

Technical Field

[0001] This invention relates to the field of chip packaging technology, and more specifically, to an apparatus and method for preparing copper sulfate electroplating solution for chip packaging. Background Technology

[0002] Copper plating is a common metal plating process that improves the appearance, performance, and corrosion resistance of metals by depositing a layer of copper onto their surfaces. Copper is considered an excellent metal interconnect material in chips due to its excellent electrical conductivity, high thermal conductivity, low melting point, and good ductility. Copper plating is a key technology for metal interconnects in packaging, and it relies heavily on high-quality plating solutions. CuSO4 copper plating solution is a commonly used copper plating solution, composed of copper sulfate (CuSO4) and other auxiliary agents.

[0003] Currently, Damascus copper interconnect technology is widely used in integrated circuit manufacturing processes. Copper deposition technology is a key technology in Damascus copper interconnect technology. Whether the copper deposited in the microgrooves (holes) is dense and free of voids or cracks directly affects the resistivity and anti-migration performance of the copper interconnect lines. The key semiconductor material for realizing Damascus copper interconnect technology is high-purity copper sulfate electroplating solution. The purity requirements of this product are very high; otherwise, the reliability of the copper wiring will be affected. At present, most methods for producing ultra-clean, high-purity copper sulfate electroplating solution for copper interconnects at home and abroad are ordinary chemical methods. This involves using high-purity copper (purity greater than 99.999%) and high-purity sulfuric acid, nitric acid, and hydrogen peroxide (SEMI-CI grade or above) as raw materials to prepare a dilute copper sulfate solution. The solution is then evaporated and concentrated to saturation, cooled, and crystallized to precipitate CuSO4·5H2O crystals. Finally, ultrapure water is used to prepare the solution according to the product's technical requirements. This method has a long process route, high requirements for raw material quality, and cannot control the fluctuation of metal impurity content in the raw materials. After the reaction, H2O2 or HNO3 needs to be removed, resulting in the emission of waste gas and wastewater, which pollutes the environment and has high production costs. For linewidth designs below 65nm, it is difficult to guarantee reliability. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned problems and provide an apparatus and method for preparing copper sulfate electroplating solution for chip packaging.

[0005] The above-mentioned technical objective of this invention is achieved through the following technical solution: comprising a pentahydrate copper sulfate storage tank, a negative pressure feeder, a feed volume silo, an electronic scale, a copper sulfate solution preparation tank, a preparation pump one, a microporous filter one, a resin tank, an electroplating solution preparation tank, a spiral nozzle, a preparation pump two, a heat exchanger, and a microporous filter two; the pentahydrate copper sulfate storage tank is connected to the copper sulfate solution preparation tank via the negative pressure feeder, the feed volume silo, and the electronic scale; the copper sulfate solution preparation tank is connected to the electroplating solution preparation tank via the microporous filter one and the resin tank; the copper sulfate solution, after being prepared in the copper sulfate solution preparation tank, is added to the electroplating solution preparation tank via the preparation pump one; the electroplating solution preparation tank, the preparation pump two, and the heat exchanger form a circulation system, and the electroplating solution is filled through the microporous filter two.

[0006] The present invention is further configured such that: the top of the copper sulfate solution preparation tank is provided with a copper sulfate pentahydrate feeding pipeline and an ultrapure water feeding pipeline, the ultrapure water feeding pipeline is equipped with a mass flow meter and a pneumatic valve; the copper sulfate pentahydrate feeding pipeline is equipped with a feed volume chamber and a pneumatic valve.

[0007] The present invention is further configured such that: the electroplating solution preparation tank is provided with electronic-grade sulfuric acid feeding pipeline, electronic-grade hydrochloric acid feeding pipeline, ultrapure water feeding pipeline and organic additive feeding pipeline, and each of the electronic-grade sulfuric acid feeding pipeline, electronic-grade hydrochloric acid feeding pipeline, ultrapure water feeding pipeline and organic additive feeding pipeline is equipped with a mass flow meter and a pneumatic valve, and the mass flow meter and the pneumatic valve are electrically connected to the DCS control system.

[0008] The present invention is further configured such that: the copper sulfate pentahydrate feeding pipeline, the ultrapure water feeding pipeline, the electroplating solution preparation tank, the preparation pump one, the preparation pump two, the heat exchanger, and the electronic grade sulfuric acid feeding pipeline, the electronic grade hydrochloric acid feeding pipeline, the ultrapure water feeding pipeline, and the organic additive feeding pipeline are all made of stainless steel 304 or 316L lined with PFA material, and the PFA is modified high-smoothness PFA material.

[0009] The present invention is further configured such that an ultrapure water adding spiral nozzle is provided inside the electroplating solution preparation tank.

[0010] The present invention is further configured such that: the first microporous filter has a fin-type pleated microporous filter element with a filter element precision of 0.1 micrometers; the second microporous filter has a fin-type pleated microporous filter element with a filter element precision of 0.05 micrometers; the microporous filter element skeleton is made of PFA material, the filter membrane is made of PTFE material, and the filter membrane is modified for hydrophilicity, with a surface tension of 35-40 mN / m after modification.

[0011] The present invention is further configured such that the resin tank is made of aminophosphonic acid chelating resin.

[0012] This invention further discloses a method for preparing a copper sulfate electroplating solution for chip packaging, which uses the aforementioned copper sulfate electroplating solution preparation apparatus for chip packaging and includes the following steps:

[0013] S1: First, add a certain amount of ultrapure water to the copper sulfate solution preparation tank, turn on the self-circulation system of the preparation tank, and the electroplating high-grade pentahydrate copper sulfate is sucked into the feeding volume hopper through the negative pressure feeder. The feeding volume hopper is placed on a high-precision electronic scale, and the weight is connected to the regulating valve at the outlet of the negative pressure feeder. The weight of the pentahydrate copper sulfate is precisely controlled by the combined process of volume and weight. The pentahydrate copper sulfate is slowly added to the preparation tank, and the circulation time is 2-4 hours.

[0014] S2: After the copper sulfate solution is prepared, it passes through a microporous filter and a resin tank to remove particulate matter and some metal ions before entering the electroplating solution preparation tank. The circulating heat exchange system of the electroplating solution preparation tank is turned on to cool it down. Then, ultrapure water, electronic grade sulfuric acid, and electronic grade hydrochloric acid are added in sequence according to the proportion. The reagents are added while circulating and cooling.

[0015] S3: Organic additives, including leveling agents, inhibitors, and accelerators, are added sequentially to the electroplating base solution. The amount of organic additives added is controlled by a mass flow meter, and the diameter of the feeding pipeline is less than 10 mm. After the additives are added, the solution is circulated for 3-6 hours and then sampled for testing. If the quality requirements are met, the electroplating solution is filled into the packaging barrel after passing through a microporous filter II. The copper sulfate prepared by this method has a stable controlled ratio: CuSO4 addition of 180-240 g / L, electronic grade sulfuric acid of 45-80 g / L, electronic grade hydrochloric acid of 40-80 ppm, accelerator of 5-15 ppm, inhibitor of 0.1-1 mg / L, and leveling agent of 0.05-0.2 mg / L.

[0016] The invention is further configured such that: the fixed volume silo in S1 is elliptical and the chamber is a smooth arc; the regulating valve at the outlet of the negative pressure feeder is interlocked with the weight of the electronic scale, and as the weight approaches the target value, the regulating valve automatically closes until it is closed.

[0017] The present invention is further configured such that the temperature during the preparation process and after preparation in S2 is controlled at 25-35°C.

[0018] The present invention is further configured such that: the mass flow meter and pneumatic valve signals on the organic additive pipeline in S3 are connected to the DCS; the addition interval for each reagent is 5-10 minutes; and the organic additives are added using high-purity nitrogen back pressure.

[0019] In summary, the present invention has the following beneficial effects:

[0020] 1. This invention purifies copper sulfate solution under weakly acidic conditions, using a preferred resin to remove metal ions such as Fe, Cr, and Ni, as well as particulate matter, thus ensuring the purity of the main raw material, copper sulfate solution; and employs a feed volume silo and weighing method to precisely control the amount of copper sulfate added.

[0021] 2. The electroplating solution preparation tank of the present invention uses stainless steel lined with modified PFA material to prevent sulfuric acid and Cl- from corroding stainless steel, while increasing the smoothness of the inner wall of the equipment and minimizing the adhesion of organic additives on the surface of the equipment, thereby affecting the electroplating solution ratio.

[0022] 3. The electroplating solution preparation tank of the present invention is equipped with an ultrapure water spiral spray head. After each production is completed, the inner wall of the preparation tank is sprayed and cleaned, and then discharged from the bottom of the preparation tank. This reduces the interference of residual substances on the wall, while cleaning away trace amounts of PFA layer precipitates and ensuring the quality of the electroplating solution.

[0023] 4. In the preparation process of the electroplating solution of the present invention, the order of thermometer materials and technology is strictly controlled to avoid excessive temperature causing oxidizing agents and other reactions of electroplating additives, thus ensuring the performance and lifespan of the electroplating solution;

[0024] 5. The copper sulfate solution and electroplating solution of the present invention use a hydrophilic microporous filter membrane, which reduces the surface tension from 15-25 mN / m of the hydrophobic membrane to 35-40 mN / m, thereby enhancing the permeability of the aqueous solution and preventing air bubbles from clogging the membrane pores and affecting the filtration efficiency.

[0025] 6. The entire preparation device of the present invention adopts automated instruments and logic control, and the whole process can realize automated and intelligent operation. Attached Figure Description

[0026] Figure 1 This is a structural diagram of the device of the present invention.

[0027] In the diagram: 1. Copper sulfate pentahydrate storage tank; 2. Negative pressure feeder; 3. Feed volume silo; 4. Electronic scale; 5. Copper sulfate solution preparation tank; 6. Preparation pump one; 7. Microporous filter one; 8. Resin tank; 9. Electroplating solution preparation tank; 10. Spiral nozzle; 11. Preparation pump two; 12. Heat exchanger; 13. Microporous filter two; 14. Copper sulfate pentahydrate feeding line; 15. Ultrapure water feeding line; 16. Mass flow meter; 17. Pneumatic valve; 18. Electronic grade sulfuric acid feeding line; 19. Electronic grade hydrochloric acid feeding line; 20. Organic additive feeding line. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be described in further detail below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0030] Example 1:

[0031] like Figure 1 As shown, a copper sulfate electroplating solution preparation device for chip packaging includes a copper sulfate pentahydrate storage tank 1, a negative pressure feeder 2, a feeding volume silo 3, an electronic scale 4, a copper sulfate solution preparation tank 5, a preparation pump 1 6, a microporous filter 1 7, a resin tank 8, an electroplating solution preparation tank 9, a spiral nozzle 10, a preparation pump 2 11, a heat exchanger 12, and a microporous filter 2 13; the resin tank 8 uses aminophosphonic acid type chelating resin.

[0032] The copper sulfate pentahydrate storage tank 1 is connected to the copper sulfate solution preparation tank 5 via a negative pressure feeder 2, a feed volume silo 3, and an electronic scale 4. The top of the copper sulfate solution preparation tank 5 is equipped with a copper sulfate pentahydrate and ultrapure water feeding pipeline 15. The ultrapure water feeding pipeline 15 is equipped with a mass flow meter 16 and a pneumatic valve 17. The copper sulfate pentahydrate feeding pipeline is equipped with a feed volume silo 3 and a pneumatic valve 17. The amount of copper sulfate added is controlled by the feed volume silo 3 and the weighing device.

[0033] The copper sulfate solution preparation tank 5 is connected to the electroplating solution preparation tank 9 via a microporous filter 7 and a resin tank 8. After the copper sulfate solution is prepared in the copper sulfate solution preparation tank 5, it is added to the electroplating solution preparation tank 9 through a preparation pump 6. The electroplating solution preparation tank 9 is equipped with an electronic grade sulfuric acid feeding pipeline 18, an electronic grade hydrochloric acid feeding pipeline 19, an ultrapure water feeding pipeline 15, and an organic additive feeding pipeline 20. Each pipeline is equipped with a mass flow meter 16 and a pneumatic valve 17. The electrical signals of the flow meters and the pneumatic valve 17 are connected to the DCS control system. The reagents required for the preparation of the electroplating solution are added in a specific order through the above pipelines to prepare the electroplating solution.

[0034] The electroplating solution preparation tank 9 is equipped with an ultrapure water addition spiral nozzle 10. Since the electroplating solution is produced intermittently, the spiral nozzle 10 is used to spray ultrapure water to clean the inner wall and device of the equipment for each batch of preparation, so as to reduce the interference of organic additives accumulated on the inner lining wall on the next batch of preparation.

[0035] The electroplating solution preparation tank 9, the preparation pump 11, and the heat exchanger 12 form a circulation system, and the electroplating solution is filled through the microporous filter 13.

[0036] Electroplating solution preparation tank 9, preparation pump 1 6, preparation pump 2 11, heat exchanger 12, and all pipelines are made of stainless steel 304 or 316L lined with PFA material, which is modified high-smoothness PFA material.

[0037] Microporous filter 17 is equipped with a fin-type pleated microporous filter element with a filter element precision of 0.1 microns; Microporous filter 213 is equipped with a fin-type pleated microporous filter element with a filter element precision of 0.05 microns; The microporous filter element skeleton is made of PFA material, and the filter membrane is made of PTFE material. The filter membrane is modified to be hydrophilic, and the surface tension after modification is 35-40 mN / m.

[0038] A method for preparing a copper sulfate electroplating solution for chip packaging, using the aforementioned apparatus, includes the following steps:

[0039] S1: First, add a certain amount of ultrapure water to the copper sulfate solution preparation tank 5, turn on the self-circulation system of the preparation tank, and the electroplating high-grade pentahydrate copper sulfate is sucked into the feeding volume chamber 3 through the negative pressure feeder 2. The feeding volume chamber 3 is placed on the high-precision electronic scale 4, and the weight is connected to the regulating valve at the outlet of the negative pressure feeder 2. The weight of the pentahydrate copper sulfate is precisely controlled by the combined process of volume and weight. The pentahydrate copper sulfate is slowly added to the preparation tank, and the circulation time is 2-4 hours.

[0040] S2: After the copper sulfate solution is prepared, it passes through a microporous filter 7 and a resin tank 8 to remove particulate matter and some metal ions before entering the electroplating solution preparation tank 9. The circulating heat exchange system of the electroplating solution preparation tank 9 is turned on to cool it down. Then, ultrapure water, electronic grade sulfuric acid, and electronic grade hydrochloric acid are added in sequence according to the proportion. The reagents are added while circulating and cooling. The temperature is controlled at 25-35℃ during the preparation process and after preparation.

[0041] S3: Organic additives, including leveling agents, inhibitors, and accelerators, are added sequentially to the electroplating base solution. The amount of organic additives added is controlled by a mass flow meter 16. The diameter of the feeding pipeline is less than 10 mm. The mass flow meter 16 and the pneumatic valve 17 on the organic additive pipeline are both connected to the DCS. Each reagent is added at 5-10 minute intervals. All organic additives are added using high-purity nitrogen backpressure to prevent air from entering the additive storage tank and pipeline. After the additives are added, the solution is circulated for 3-6 hours and then sampled for testing. After meeting the quality requirements, the electroplating solution is filled into the packaging barrel after passing through the microporous filter 13. The copper sulfate prepared by this method has a stable controlled ratio: CuSO4 addition of 180-240 g / L and electronic grade sulfuric acid of 45-80 g / L. The fixed-volume silo in S1 is elliptical with a smooth arc to avoid raw material residue. The regulating valve at the outlet of the negative pressure feeder 2 is interlocked with the electronic scale 4. As the weight approaches the target value, the regulating valve automatically closes until it is closed, thus precisely controlling the weight.

[0042] Specific experiments:

[0043] Add 720 kg of copper sulfate pentahydrate to a volume of 2 m³. 3 The solution was circulated in ultrapure water for 4 hours, then passed through a 0.1μm microporous pleated filter and resin. The circulating heat exchange system of electroplating solution preparation tank 9 was then turned on. Ultrapure water, electronic-grade sulfuric acid, and electronic-grade hydrochloric acid were added sequentially according to the specified ratio, while simultaneously circulating and cooling down to 35℃. Then, 1m³ of ultrapure water was slowly added, maintaining the solution temperature at 35℃. Electroplating additives, including leveling agent, inhibitor, and accelerator, were added sequentially according to the specified ratio. After addition, the solution was circulated for 6 hours. The prepared electroplating solution contained the following components: CuSO₄ 233g / L, sulfate 65g / L, chloride ions 72ppm, accelerator 13ppm, inhibitor 0.8mg / L, and leveling agent 0.15mg / L. Impurities in the electroplating solution, including Fe, Cr, and Ni, were <10ppb, and 0.1μm particles were <10pcs / mL.

[0044] Example 2:

[0045] 600 kg of copper sulfate pentahydrate was added to 2 m³ of ultrapure water and circulated for 2 hours. The solution was then passed through a 0.1 μm microporous pleated filter and resin. The circulating heat exchange system of electroplating solution preparation tank 9 was turned on, and ultrapure water, electronic-grade sulfuric acid, and electronic-grade hydrochloric acid were added sequentially according to the specified ratio, while simultaneously circulating and cooling until the temperature reached 35°C. Then, 1 m³ of ultrapure water was slowly added, maintaining the solution temperature at 30°C. Electroplating additives, including leveling agent, inhibitor, and accelerator, were then added sequentially according to the specified ratio. After all additions were completed, the solution was circulated for 3 hours. The composition of the prepared electroplating solution was as follows: CuSO₄ content 204 g / L, sulfate ion 61 g / L, chloride ion 69 ppm, accelerator 11 ppm, inhibitor 0.6 mg / L, and leveling agent 0.13 mg / L. The impurities in the electroplating solution, including Fe, Cr, and Ni ions, were <10 ppb, and 0.1 μm particles were <10 pcs / mL.

[0046] Implementation Case 3:

[0047] 540 kg of copper sulfate pentahydrate was added to 2 m³ of ultrapure water and circulated for 4 hours. The solution was then passed through a 0.1 μm microporous pleated filter and resin. The circulating heat exchange system of electroplating solution preparation tank 9 was turned on, and ultrapure water, electronic-grade sulfuric acid, and electronic-grade hydrochloric acid were added sequentially according to the specified ratio, while simultaneously circulating and cooling down to 35°C. Then, 1 m³ of ultrapure water was slowly added, maintaining the solution temperature at 25°C. Electroplating additives, including leveling agent, inhibitor, and accelerator, were then added sequentially according to the specified ratio. After all additions were completed, the solution was circulated for 6 hours. The composition of the prepared electroplating solution was as follows: CuSO₄ content 208 g / L, sulfate ion 53 g / L, chloride ion 55 ppm, accelerator 7 ppm, inhibitor 0.2 mg / L, and leveling agent 0.06 mg / L. The impurities in the electroplating solution, including Fe, Cr, and Ni, were <10 ppb, and 0.1 μm particles were <10 pcs / mL.

[0048] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. An apparatus for preparing copper sulfate electroplating solution for chip packaging, characterized in that: The system includes a copper sulfate pentahydrate storage tank (1), a negative pressure feeder (2), a feed volume silo (3), an electronic scale (4), a copper sulfate solution preparation tank (5), a preparation pump one (6), a microporous filter one (7), a resin tank (8), an electroplating solution preparation tank (9), a spiral nozzle (10), a preparation pump two (11), a heat exchanger (12), and a microporous filter two (13); the copper sulfate pentahydrate storage tank (1) is fed by the negative pressure feeder (2), the feed volume silo (3), and the electronic scale (4). The copper sulfate solution preparation tank (5) is connected to the copper sulfate solution preparation tank (5) through a microporous filter (7) and a resin tank (8). The copper sulfate solution is prepared in the copper sulfate solution preparation tank (5) and then added to the electroplating solution preparation tank (9) through a preparation pump (6). The electroplating solution preparation tank (9) forms a circulation system with the preparation pump (11) and the heat exchanger (12), and is filled with electroplating solution through a microporous filter (13). The copper sulfate solution preparation tank (5) is equipped with a copper sulfate pentahydrate feeding pipeline (14) and an ultrapure water feeding pipeline (15) at the top. The ultrapure water feeding pipeline (15) is equipped with a mass flow meter (16) and a pneumatic valve (17). The copper sulfate pentahydrate feeding pipeline is equipped with a feed volume hopper (3) and a pneumatic valve (17). The electroplating solution preparation tank (9) is equipped with an electronic-grade sulfuric acid feeding line (18), an electronic-grade hydrochloric acid feeding line (19), an ultrapure water feeding line (15), and an organic additive feeding line (20). Each of the electronic-grade sulfuric acid feeding line (18), electronic-grade hydrochloric acid feeding line (19), ultrapure water feeding line (15), and organic additive feeding line (20) is equipped with a mass flow meter (16) and a pneumatic valve (17). The mass flow meter (16) and the pneumatic valve (17) are connected to the DCS control system via electrical signals.

2. The apparatus for preparing copper sulfate electroplating solution for chip packaging according to claim 1, characterized in that: The copper sulfate pentahydrate feeding pipeline (14), ultrapure water feeding pipeline (15), electroplating solution preparation tank (9), preparation pump one (6), preparation pump two (11), heat exchanger (12), electronic grade sulfuric acid feeding pipeline (18), electronic grade hydrochloric acid feeding pipeline (19), ultrapure water feeding pipeline (15) and organic additive feeding pipeline (20) are all made of stainless steel 304 or 316L lined with PFA material, and the PFA is modified high-smoothness PFA material.

3. The apparatus for preparing copper sulfate electroplating solution for chip packaging according to claim 1, characterized in that: The electroplating solution preparation tank (9) is equipped with an ultrapure water adding spiral nozzle (10).

4. The apparatus for preparing copper sulfate electroplating solution for chip packaging according to claim 1, characterized in that: The microporous filter one (7) is equipped with a fin-type pleated microporous filter element with a filter element precision of 0.1 micrometers; the microporous filter two (13) is equipped with a fin-type pleated microporous filter element with a filter element precision of 0.05 micrometers; the microporous filter element skeleton is made of PFA material, the filter membrane is made of PTFE material, the filter membrane is modified for hydrophilicity, and the surface tension after modification is 35-40mN / m.

5. The apparatus for preparing copper sulfate electroplating solution for chip packaging according to claim 1, characterized in that: The resin tank (8) is made of aminophosphonic acid chelating resin.

6. A method for preparing a copper sulfate electroplating solution for chip packaging, characterized in that: The preparation of the copper sulfate electroplating solution for chip packaging, using any one of claims 1 to 5, includes the following steps: S1: First, add a certain amount of ultrapure water to the copper sulfate solution preparation tank (5), turn on the self-circulation system of the preparation tank, and the electroplated high-grade pentahydrate copper sulfate is sucked into the feed volume chamber (3) through the negative pressure feeder (2). The feed volume chamber (3) is placed on the high-precision electronic scale (4), and the weight is connected to the regulating valve at the outlet of the negative pressure feeder (2). The weight of the pentahydrate copper sulfate is precisely controlled by the combined process of volume and weight. The pentahydrate copper sulfate is slowly added to the preparation tank, and the circulation time is 2-4 hours. S2: After the copper sulfate solution is prepared, it passes through a microporous filter (7) and a resin tank (8) to remove particulate matter and some metal ions before entering the electroplating solution preparation tank (9). The circulating heat exchange system of the electroplating solution preparation tank (9) is turned on to cool down. Then, ultrapure water, electronic grade sulfuric acid and electronic grade hydrochloric acid are added in sequence according to the proportion. The reagents are added while circulating and cooling down. S3: Organic additives, including leveling agent, inhibitor, and accelerator, are added sequentially to the electroplating base solution. The amount of organic additives added is controlled by a mass flow meter (16), and the diameter of the feeding pipeline is less than 10 mm. After the additives are added, the solution is circulated for 3 to 6 hours and then sampled for testing. After meeting the quality requirements, the electroplating solution is filled into the packaging barrel after passing through a microporous filter II (13). The copper sulfate prepared by this method has a stable control ratio: CuSO4 addition amount is 180 to 240 g / L, electronic grade sulfuric acid 45 to 80 g / L, electronic grade hydrochloric acid 40 to 80 ppm, accelerator 5 to 15 ppm, inhibitor 0.1 to 1 mg / L, and leveling agent 0.05 to 0.2 mg / L.

7. The method for preparing a copper sulfate electroplating solution for chip packaging according to claim 6, characterized in that: The fixed volume silo in S1 is elliptical and the body is a smooth arc. The regulating valve at the outlet of the negative pressure feeder (2) is interlocked with the weight of the electronic scale (4). As the weight approaches the target value, the regulating valve automatically closes until it is closed.

8. The method for preparing a copper sulfate electroplating solution for chip packaging according to claim 6, characterized in that: The preparation process and the temperature after preparation in S2 are both controlled at 25-35℃.

9. The method for preparing a copper sulfate electroplating solution for chip packaging according to claim 6, characterized in that: The mass flow meter (16) and pneumatic valve (17) on the organic additive pipeline in S3 are connected to the DCS. Each reagent is added at intervals of 5-10 minutes. All organic additives are added using high-purity nitrogen back pressure.

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