Electroless copper plating solution, production process and application for improving surface roughness

Abstract

The present invention discloses an electroless copper plating solution, a production process and an application thereof that are helpful for improving surface roughness, belonging to the technical field of electroless copper plating solutions. Each liter of the electroless copper plating solution includes the following raw materials: copper salt: 16.1 - 21.8 g; reducing agent: 3.6 - 5.2 g; complexing agent: 10.3 - 12.5 g; pH regulator: 9.3 - 23.5 g; inhibitor: 3.8 - 6.2 g; surface modification auxiliary agent: 0.08 - 0.21 g; the balance is deionized water; the inhibitor includes the following raw materials in weight percentages: silane coupling agent 25.7 - 35.2%, polyacrylate 16.9 - 22.3%, sucrose 16.2 - 18.6%, and the balance is deionized water; the surface modification auxiliary agent adopts polyethylene glycol-modified sodium alginate nanogel; the inhibitor of the present invention has a weak affinity for copper ions, avoiding the generation of unstable intermediate products or precipitates during the reaction from affecting the stability of the plating solution. The prepared plating solution has no obvious turbidity and impurities, the flatness of the copper plating layer is good, and the surface roughness is effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of chemical copper plating solution, and in particular to a chemical copper plating solution, a production process and an application thereof which are helpful in improving surface roughness. Background Art

[0002] Chemical copper plating technology is a technology that uses chemical reducing agents to reduce copper ions in the solution into metallic copper and deposit it on the surface of the plated part without an external current. It is commonly used in the fields of printed circuit board (PCB) manufacturing and plastic electroplating.

[0003] The ingredients of chemical copper plating solution generally contain copper salts, reducing agents, chelating agents and pH adjusters. Common copper salts include copper sulfate, copper chloride, copper nitrate, etc., reducing agents include formaldehyde, etc., chelating agents include EDTA, disodium EDTA, etc., and pH adjusters include sodium hydroxide, etc.

[0004] At present, in order to improve the surface roughness of products, the method of adding brighteners, leveling agents, and inhibitors (such as benzotriazole (BTA) etc.) is generally adopted. Among them, the inhibitor principle is: the inhibitor molecules can selectively adsorb on the active sites on the surface of the plated part or the growth points of the copper crystals, preventing new copper atoms from continuing to deposit at the positions where the inhibitors have been adsorbed. Copper atoms can only be deposited in areas not covered by the inhibitors, thereby changing the growth mode of the copper crystals, slowing down the growth rate, and making the growth of the crystals more orderly, which is conducive to the formation of a delicate and uniform copper plating layer. At the same time, the inhibitor reacts with copper salts to form a protective film on the surface of the copper plating layer, further limiting the disordered growth of copper crystals, which is conducive to improving the surface roughness of the copper plating layer.

[0005] However, the inhibitor may have complex interactions with other components in the plating solution. For example, if the inhibitor is a nitrogen-containing heterocyclic compound, it may compete with the complexing agent for coordination with the copper ions. If the inhibitor has a strong affinity for copper ions, it will seize copper ions from the complexing agent-copper ion complex to form an inhibitor-copper ion complex. On the one hand, this reaction may produce unstable intermediates or precipitates, affecting the stability of the plating solution and causing the plating solution to become turbid. If it is mixed in the copper plating layer, it will affect the quality of the copper plating layer. On the other hand, the new complex or precipitate generated adheres to the surface of the plated part, which will reduce the flatness of the copper plating layer and increase the surface roughness.

[0006] Based on this, the present invention designs a chemical copper plating solution, a production process and an application that are helpful to improve the surface roughness to solve the above problems. Summary of the invention

[0007] In view of the above-mentioned shortcomings of the prior art, the present invention provides a chemical copper plating solution, a production process and an application thereof which are helpful in improving surface roughness.

[0008] To achieve the above object, the present invention is realized through the following technical solutions:

[0009] A electroless copper plating solution helpful for improving surface roughness, and each 1 liter of the electroless copper plating solution includes the following raw materials:

[0010] Copper salt: 16.1 - 21.8 g;

[0011] Reducing agent: 3.6 - 5.2 g;

[0012] Complexing agent: 10.3 - 12.5 g;

[0013] pH regulator: 9.3 - 23.5 g;

[0014] Inhibitor: 3.8 - 6.2 g;

[0015] Surface modification auxiliary agent: 0.08 - 0.21 g;

[0016] The balance is deionized water;

[0017] The inhibitor includes raw materials in the following weight percentages: silane coupling agent 25.7 - 35.2%, polyacrylate 16.9 - 22.3%, sucrose 16.2 - 18.6%, and the balance is deionized water;

[0018] The surface modification auxiliary agent adopts polyethylene glycol modified sodium alginate nanogel; by freeze - drying and crushing the sodium alginate nanogel and then adding it into an aqueous solution of polyethylene glycol with a concentration of 15.3 - 18.6 w% for swelling reaction for 15 - 20 minutes, polyethylene glycol modified sodium alginate nanogel is obtained.

[0019] Furthermore, the silane coupling agent is selected as γ - glycidoxypropyltrimethoxysilane.

[0020] Furthermore, the polyacrylate is selected as sodium polyacrylate.

[0021] Furthermore, the preparation method of the inhibitor is as follows:

[0022] Step (1), at room temperature, sucrose is added to deionized water to form a sucrose solution;

[0023] Step (2), heating to 48 - 60 °C, controlling the stirring speed at 300 - 350 revolutions per minute, and slowly adding 1 / 2 of the silane coupling agent to the sucrose solution. The silane coupling agent is uniformly dispersed and hydrolyzed for 30 - 35 minutes to provide active sites for the reaction;

[0024] Step (3): Mix the remaining 1 / 2 of the silane coupling agent with polyacrylate at 45 - 55 °C and stir at a speed of 150 - 200 revolutions per minute for 40 - 55 minutes to ensure full reaction.

[0025] Step (4): Adjust the pH value of the solution obtained in step (2) to 10 - 11, and drop the product obtained in step (3) into the solution obtained in step (2) at a dropping rate controlled at 1.5 - 3.0 grams per minute, with a stirring speed of 300 - 500 revolutions per minute.

[0026] Furthermore, the complexing agent is selected from a mixture of sodium tripolyphosphate, nitrilotriacetic acid, and sodium tartrate in a ratio of 2 - 2.2:3.1 - 3.7:0.5 - 1.

[0027] Furthermore, the copper salt is selected from one or a combination of copper sulfate, copper chloride, and copper nitrate.

[0028] Furthermore, the reducing agent is selected from sodium hypophosphite.

[0029] Furthermore, the pH regulator is selected from sodium hydroxide.

[0030] To better achieve the object of the present invention, the present invention also provides a production process of the electroless copper plating solution for improving surface roughness, including the following steps:

[0031] Step a: At room temperature, stir and mix the inhibitor and the surface modification assistant evenly to obtain mixture A for standby.

[0032] Step b: Take a container and add deionized water, then slowly add the copper salt to the deionized water while stirring, with the stirring speed controlled at 100 - 150 revolutions per minute to obtain a solution with uniformly distributed copper ions.

[0033] Step c: Add the complexing agent to the container of the solution with uniformly distributed copper ions, also add it slowly and stir, with the stirring speed controlled at 150 - 185 revolutions per minute to fully complex the complexing agent with the copper ions, and then adjust the pH value of the solution to 11 - 13 with the pH regulator to obtain mixture B.

[0034] Step d: Then add the reducing agent to mixture B and stir for 10 - 15 minutes; then add mixture A, with the stirring speed controlled at 200 - 255 revolutions per minute and stir for 15 - 20 minutes to obtain the electroless copper plating solution for improving surface roughness.

[0035] To better achieve the object of the present invention, the present invention also provides the application of the electroless copper plating solution in the fields of printed circuit board manufacturing and plastic electroplating.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows: The inhibitor of the present invention has a weak affinity for copper ions, avoiding the generation of unstable intermediate products or precipitates during the reaction, which may affect the stability of the plating solution. The prepared plating solution has no obvious turbidity and impurities, the flatness of the copper plating layer is good, and the surface roughness is effectively reduced. When preparing the inhibitor, first prepare a sucrose solution; then add half of the silane coupling agent to the sucrose solution for uniform dispersion and hydrolysis to provide active sites for the reaction, and adjust the pH value of the obtained solution to 10-11. Using half of the silane coupling agent can avoid too violent hydrolysis reaction, too fast generation speed and uneven distribution of active sites, which is not conducive to subsequent orderly reactions. Then mix the remaining half of the silane coupling agent with polyacrylate to form a relatively stable intermediate product, which is conducive to more orderly further reactions; finally, mix the two solutions, which is conducive to avoiding too violent reactions caused by mixing all reactants at once and affecting the effect of the inhibitor. The surface modification adjuvant uses polyethylene glycol-modified sodium alginate nanogel, enabling polyethylene glycol molecules to penetrate into the interior of the gel and interact with the sodium alginate molecular chain to effectively modify the sodium alginate nanogel, reducing the surface energy, better adsorbing on the surface of the workpiece to be plated, enhancing the network structure stability of the gel, being conducive to reducing the surface roughness, enhancing the bonding force between the plating layer and the workpiece to be plated, and enhancing the bending resistance. Specific Embodiments

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0038] Example 1: The production process of electroless copper plating solution helpful for improving surface roughness includes the following steps:

[0039] Step 1: Weigh the raw materials: Each 1 liter of electroless copper plating solution includes the following raw materials: copper salt: 16.1 g, copper sulfate; reducing agent: 5.2 g, sodium hypophosphite; complexing agent: 10.3 g, a mixture of sodium tripolyphosphate, nitrilotriacetic acid, and sodium tartrate in a ratio of 2.2:3.1:1; pH regulator: 9.3 g, sodium hydroxide; inhibitor: 6.2 g; surface modification adjuvant: 0.08 g; the balance is deionized water.

[0040] The inhibitor comprises raw materials in the following weight percentages: 25.7% of silane coupling agent, 22.3% of polyacrylate, 16.2% of sucrose, and the balance being deionized water; the silane coupling agent is selected as γ-glycidoxypropyltrimethoxysilane; the polyacrylate is selected as sodium polyacrylate. The preparation method of the inhibitor is as follows: Step (1), at room temperature, sucrose is added to deionized water to form a sucrose solution; Step (2), the temperature is raised to 48 °C, the stirring speed is controlled at 350 revolutions per minute, and 1 / 2 of the silane coupling agent is slowly added to the sucrose solution, and the silane coupling agent is uniformly dispersed and hydrolyzed for 30 minutes to provide active sites for the reaction; Step (3), at 55 °C, the remaining 1 / 2 of the silane coupling agent is mixed with the polyacrylate, and stirred at a speed of 150 revolutions per minute for 55 minutes to ensure full progress of the reaction; Step (4), the pH value of the solution obtained in Step (2) is adjusted to 10 - 11, and the product obtained in Step (3) is added dropwise to the solution obtained in Step (2), and the dropping speed is controlled at 1.5 grams per minute, and the stirring speed is 500 revolutions per minute.

[0041] The surface modification assistant adopts polyethylene glycol modified sodium alginate nanogel; by freeze-drying and pulverizing the sodium alginate nanogel and then adding it to an aqueous solution of polyethylene glycol with a concentration of 15.3 w% for a swelling reaction for 20 minutes, polyethylene glycol modified sodium alginate nanogel is obtained.

[0042] Step 2, at room temperature, the inhibitor and the surface modification assistant are stirred and mixed evenly to obtain mixture A for standby;

[0043] Step 3, take a container and add deionized water, then slowly add the copper salt to the deionized water while stirring, and the stirring speed is controlled at 100 revolutions per minute to obtain a solution with uniformly distributed copper ions;

[0044] Step 4, add a complexing agent to the container with the solution of uniformly distributed copper ions, and also add it slowly while stirring, and the stirring speed is controlled at 150 revolutions per minute to fully complex the complexing agent with the copper ions, and then adjust the pH value of the solution to 11 - 13 with a pH regulator to obtain mixture B;

[0045] Step 5, then add a reducing agent to mixture B and stir for 10 minutes; then add mixture A, and the stirring speed is controlled at 255 revolutions per minute and stir for 15 minutes to obtain an electroless copper plating solution that helps to improve the surface roughness.

[0046] Example 2: The production process of an electroless copper plating solution that helps to improve the surface roughness, comprising the following steps:

[0047] Step 1. Weigh the raw materials: In every 1 liter of electroless copper plating solution, it includes the following raw materials: copper salts: 21.8 g, a composition of copper chloride and copper nitrate with a mass ratio of 1:1; reducing agent: 3.6 g, sodium hypophosphite; complexing agent: 12.5 g, a mixture of sodium tripolyphosphate, nitrilotriacetic acid and sodium tartrate in a ratio of 2:3.7:0.5; pH regulator: 23.5 g, sodium hydroxide; inhibitor: 3.8 g; surface modification auxiliary agent: 0.21 g; the balance is deionized water.

[0048] The inhibitor includes raw materials with the following weight percentages: silane coupling agent 35.2%, polyacrylate 16.9%, sucrose 18.6%, and the balance is deionized water; the silane coupling agent is selected as γ-glycidoxypropyltrimethoxysilane; the polyacrylate is selected as sodium polyacrylate. The preparation method of the inhibitor is as follows: Step (1), at room temperature, sucrose is added to deionized water to form a sucrose solution; Step (2), the temperature is raised to 60 °C, the stirring speed is controlled at 300 revolutions per minute, and 1 / 2 of the silane coupling agent is slowly added to the sucrose solution, and the silane coupling agent is uniformly dispersed and hydrolyzed for 35 minutes to provide active sites for the reaction; Step (3), at 45 °C, the remaining 1 / 2 of the silane coupling agent is mixed with the polyacrylate, and stirred at a speed of 200 revolutions per minute for 40 minutes to ensure that the reaction proceeds fully; Step (4), adjust the pH value of the solution obtained in Step (2) to 10 - 11, and drop the product obtained in Step (3) into the solution obtained in Step (2), with the dropping speed controlled at 3.0 g / minute and the stirring speed at 300 revolutions per minute.

[0049] The surface modification auxiliary agent adopts polyethylene glycol-modified sodium alginate nanogel; by freeze-drying and pulverizing the sodium alginate nanogel and then adding it to an aqueous solution of polyethylene glycol with a concentration of 18.6 w% for a swelling reaction for 15 minutes, polyethylene glycol-modified sodium alginate nanogel is obtained.

[0050] Step 2. At room temperature, the inhibitor and the surface modification auxiliary agent are stirred and mixed evenly to obtain mixture A for standby.

[0051] Step 3. Take a container and add deionized water, then slowly add the copper salts to the deionized water while stirring, with the stirring speed controlled at 150 revolutions per minute to obtain a solution with uniformly distributed copper ions.

[0052] Step 4. Add the complexing agent to the container with the solution of uniformly distributed copper ions, also add it slowly and stir, with the stirring speed controlled at 150 revolutions per minute to make the complexing agent fully complex with the copper ions, and then adjust the pH value of the solution to 11 - 13 with the pH regulator to obtain mixture B.

[0053] Step 5: Then, a reducing agent is added to mixture B and stirred for 15 minutes; then mixture A is added, and the stirring speed is controlled at 200 revolutions per minute and stirred for 20 minutes to obtain an electroless copper plating solution that helps improve surface roughness.

[0054] Example 3: A production process of an electroless copper plating solution that helps improve surface roughness, including the following steps:

[0055] Step 1: Weigh the raw materials: Each 1 liter of electroless copper plating solution includes the following raw materials: copper salt: 18.5 g, copper chloride; reducing agent: 4.6 g, sodium hypophosphite; complexing agent: 11.4 g, a mixture of sodium tripolyphosphate, nitrilotriacetic acid, and sodium tartrate in a ratio of 2.1:3.5:0.7; pH regulator: 15.5 g, sodium hydroxide; inhibitor: 5.3 g; surface modification auxiliary agent: 0.12 g; the balance is deionized water.

[0056] The inhibitor includes the following raw materials by weight percentage: silane coupling agent 28.9%, polyacrylate 18.6%, sucrose 17.1%, and the balance is deionized water; the silane coupling agent is selected as γ-glycidoxypropyltrimethoxysilane; the polyacrylate is selected as sodium polyacrylate. The preparation method of the inhibitor is as follows: Step (1): Under normal temperature conditions, sucrose is added to deionized water to form a sucrose solution; Step (2): The temperature is raised to 55°C, and the stirring speed is controlled at 320 revolutions per minute. Slowly add 1 / 2 of the silane coupling agent to the sucrose solution, and the silane coupling agent is uniformly dispersed and hydrolyzed for 32 minutes to provide active sites for the reaction; Step (3): Under the condition of 48°C, mix the remaining 1 / 2 of the silane coupling agent with the polyacrylate and stir at a speed of 180 revolutions per minute for 45 minutes to ensure that the reaction proceeds fully; Step (4): Adjust the pH value of the solution obtained in Step (2) to 10 - 11, and drop the product obtained in Step (3) into the solution obtained in Step (2) at a dropping speed of 2 g / minute and a stirring speed of 400 revolutions per minute.

[0057] The surface modification auxiliary agent uses polyethylene glycol-modified sodium alginate nanogel; by freeze-drying and crushing the sodium alginate nanogel and adding it to an aqueous solution of polyethylene glycol with a concentration of 16.8 w% for a swelling reaction for 18 minutes, polyethylene glycol-modified sodium alginate nanogel is obtained.

[0058] Step 2: At normal temperature, the inhibitor and the surface modification auxiliary agent are stirred and mixed evenly to obtain mixture A for standby.

[0059] Step 3: Take a container and add deionized water, then slowly add the copper salt to the deionized water while stirring, and the stirring speed is controlled at 130 revolutions per minute to obtain a solution with uniformly distributed copper ions.

[0060] Step 4: Add a complexing agent to the solution container with uniformly distributed copper ions, and also add it slowly while stirring. Control the stirring speed at 170 revolutions per minute to allow the complexing agent to fully complex with the copper ions. Then, adjust the pH value of the solution to 11 - 13 using a pH regulator to obtain Mixture B.

[0061] Step 5: Then, add a reducing agent to Mixture B and stir for 12 minutes; then add Mixture A and control the stirring speed at 250 revolutions per minute and stir for 17 minutes to obtain an electroless copper plating solution that helps improve surface roughness.

[0062] Comparative Example 1: The difference from Example 3 is that the preparation method of the inhibitor is replaced with: directly blending a silane coupling agent, polyacrylate, sucrose, and deionized water.

[0063] Comparative Example 2: The difference from Example 3 is that the surface modification auxiliary agent is replaced with sodium alginate nanogel.

[0064] Comparative Example 3: The difference from Example 3 is that the inhibitor is replaced with benzotriazole.

[0065] Experimental Example: Respectively place the workpieces to be plated (ABS plastic) into the electroless copper plating solutions of Examples 1 - 3 and Comparative Examples 1 - 3 at 75 °C for 1 h to obtain plated workpieces, and detect the performance of each plated workpiece. The results are shown in Table 1.

[0066] Surface roughness: GB / T 3505 - 2009.

[0067] Test for the adhesion between the coating and the workpiece to be plated: Coating adhesion scratch tester.

[0068] Bending test: Repeatedly bend the plated workpiece 120 degrees until cracks appear in the copper plating layer and then stop, and record the number of bending times.

[0069] Table 1 Performance test results

[0070]

[0071] The inhibitor of the present invention has a weak affinity for copper ions, avoiding the generation of unstable intermediate products or precipitates during the reaction, which may affect the stability of the plating solution. The prepared plating solution has no obvious turbidity and impurities, and the flatness of the copper plating layer is good, and the surface roughness is effectively reduced. When preparing the inhibitor, a sucrose solution is first prepared; then 1 / 2 of the silane coupling agent is added to the sucrose solution for uniform dispersion and hydrolysis to provide active sites for the reaction, and the pH value of the obtained solution is adjusted to 10-11. Using 1 / 2 of the silane coupling agent can avoid too violent hydrolysis reaction, too fast generation rate and uneven distribution of active sites, which is not conducive to subsequent orderly reactions. Then the remaining 1 / 2 of the silane coupling agent is mixed and reacted with polyacrylate to form a relatively stable intermediate product, which is conducive to more orderly further reactions; finally, the two solutions are mixed, which is conducive to avoiding too violent reactions caused by the one-time mixing of all reactants and affecting the inhibitor effect. The surface modification adjuvant uses polyethylene glycol-modified sodium alginate nanogel, enabling polyethylene glycol molecules to penetrate into the interior of the gel and interact with the molecular chains of sodium alginate to effectively modify the sodium alginate nanogel, reducing the surface energy, being able to better adsorb on the surface of the workpiece to be plated, enhancing the network structure stability of the gel, being conducive to reducing the surface roughness, enhancing the adhesion between the plating layer and the workpiece to be plated, and enhancing the bending resistance.

[0072] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A chemical copper plating solution that helps improve surface roughness, characterized in that: Each 1 liter of chemical copper plating solution includes the following raw materials: Copper salt: 16.1-21.8 g; Reducing agent: 3.6-5.2 g; Complexing agent: 10.3-12.5 g; pH adjuster: 9.3-23.5 g; Inhibitor: 3.8-6.2 g; Surface modification auxiliary agent: 0.08-0.21 g; The balance is deionized water; The inhibitor comprises the following raw materials in weight percentage: 25.7-35.2% of silane coupling agent, 16.9-22.3% of polyacrylate, 16.2-18.6% of sucrose, and the balance of deionized water. The preparation method of the inhibitor comprises the following steps: step (1), at room temperature, sucrose is added into deionized water to form a sucrose solution; step (2), heating to 48-60° C., stirring at 300-350 rpm, slowly adding 1 / 2 of the silane coupling agent into the sucrose solution, and the silane coupling agent is evenly dispersed and Hydrolyze for 30-35 minutes to provide active sites for the reaction; step (3), at 45-55°C, mix the remaining 1 / 2 of the silane coupling agent with the polyacrylate, and stir at 150-200 rpm for 40-55 minutes to ensure that the reaction is fully carried out; step (4), adjust the pH value of the solution obtained in step (2) to 10-11, and add the product obtained in step (3) dropwise to the solution obtained in step (2), with the dropping speed controlled at 1.5-3.0 g / min and the stirring speed at 300-500 rpm; The surface modification auxiliary agent is polyethylene glycol-modified sodium alginate nanogel; the polyethylene glycol-modified sodium alginate nanogel is obtained by freeze-drying and crushing the sodium alginate nanogel and then adding the resulting solution to polyethylene glycol with a concentration of 15.3-18.6w% for swelling reaction for 15-20 minutes.

2. The chemical copper plating solution for improving surface roughness according to claim 1, characterized in that: The silane coupling agent is γ-glycidyloxypropyltrimethoxysilane.

3. The chemical copper plating solution for improving surface roughness according to claim 2, characterized in that: The polyacrylate is sodium polyacrylate.

4. The chemical copper plating solution for improving surface roughness according to claim 3, characterized in that: The complexing agent is a mixture of sodium tripolyphosphate, nitrilotriacetic acid and sodium tartrate in a ratio of 2-2.2:3.1-3.7:0.5-1.

5. The chemical copper plating solution for improving surface roughness according to claim 4, characterized in that: The copper salt is selected from a combination of one or more of copper sulfate, copper chloride and copper nitrate.

6. The chemical copper plating solution for improving surface roughness according to claim 5, characterized in that: The reducing agent is sodium hypophosphite.

7. The chemical copper plating solution for improving surface roughness according to claim 6, characterized in that: The pH regulator is sodium hydroxide.

8. A method for preparing a chemical copper plating solution that helps improve surface roughness according to claim 7, characterized in that: The following steps are involved: Step a, at room temperature, stirring and mixing the inhibitor and the surface modification auxiliary agent to obtain a mixture A for standby use; Step b, taking a container and adding deionized water, then slowly adding copper salt into the deionized water, stirring while adding, and controlling the stirring speed at 100-150 rpm to obtain a solution with uniformly distributed copper ions; Step c, adding a complexing agent to a solution container in which copper ions are evenly distributed, also slowly adding and stirring, the stirring speed is controlled at 150-185 rpm, so that the complexing agent and the copper ions are fully complexed, and then adjusting the pH value of the solution to 11-13 with a pH adjusting agent to obtain a mixture B; Step d: then add a reducing agent to the mixture B and stir for 10-15 minutes; then add the mixture A, control the stirring speed at 200-255 rpm, and stir for 15-20 minutes to obtain a chemical copper plating solution that helps improve the surface roughness.

9. Use of the chemical copper plating solution according to any one of claims 1 to 7 in the fields of printed circuit board manufacturing and plastic electroplating.

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