Double-reducing-agent chemical copper plating solution suitable for PET copper plating and application of double-reducing-agent chemical copper plating solution

Abstract

The invention belongs to the technical field of chemical plating, and particularly relates to a double-reducing-agent chemical copper plating solution suitable for PET copper plating and application, and the double-reducing-agent chemical copper plating solution comprises 6-10 g / L of copper sulfate, 15-25 g / L of sodium hypophosphite, 40-60 mg / L of dimethylamino borane, 15-30 g / L of a complexing agent, 10-20 mg / L of a stabilizer, 0.5-1.5 mg / L of an accelerator, 0.5-1.5 g / L of metal ion salt and 200-300 mg / L of an anionic surfactant. According to the double-reducing-agent chemical copper plating solution, the production cost of composite copper foil can be reduced, the electrical resistivity of a copper plating layer is reduced, the binding force between PET and the copper plating layer is increased, and the copper plating speed of the chemical copper plating solution is increased.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical plating, and in particular relates to a double-reducing agent chemical copper plating solution suitable for PET copper plating and an application thereof. Background Art

[0002] As a high-performance material with great potential, composite copper foil occupies an important position in modern industry. It uses plastic as the substrate and covers the surface with conductive metal, giving the material excellent electrical and mechanical properties. Among the many covering methods, vapor deposition, cathode sputtering, chemical plating, metal spraying, etc. each has its own characteristics. Although methods such as vapor deposition and metal spraying can achieve high-quality metal coverage, the cost is relatively high, which makes them face certain challenges in large-scale industrial applications. In contrast, chemical plating has a lower cost and can also achieve a more ideal effect, so it has been widely used in industry.

[0003] In the process of chemical plating, the selection of reducing agent is crucial. Formaldehyde is commonly used as a reducing agent in traditional methods. However, formaldehyde will produce toxic gases under high temperature conditions, which not only causes serious pollution to the environment, but also poses a huge threat to the health of operators. In order to solve this problem, the industry has gradually begun to use sodium hypophosphite as a substitute. Although sodium hypophosphite has obvious advantages in environmental protection, its reducing ability is not as good as formaldehyde. When a complexing agent is added to the chemical copper plating solution, especially a double complexing agent, the plating speed will be significantly slowed down, and even no reaction may occur, which will undoubtedly increase the production time cost and affect the production efficiency. For PET composite copper foil, the quality of its bonding strength is not only closely related to the roughening link in the pretreatment, but also has an important relationship with the composition of the chemical plating solution. The composition of the chemical copper plating solution plays a key role in the quality of the copper plating effect, such as surface morphology and resistance. Chinese patent application CN201310191861.8 discloses a plastic copper plating solution, but its effect of copper plating on the surface of PET plastic is not ideal.

[0004] Therefore, it is very necessary to develop a double reducing agent chemical copper plating solution suitable for PET copper plating. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the prior art and provide a double reducing agent chemical copper plating solution suitable for PET copper plating and its application, which can reduce the production cost of composite copper foil, reduce the resistivity of the copper plating layer, increase the bonding force between PET and the copper plating layer, and increase the copper plating speed of the chemical copper plating solution.

[0006] In order to achieve the above purpose, one of the technical solutions of the present invention is: a double reducing agent chemical copper plating solution suitable for PET copper plating, whose components include: 6-10g / L copper sulfate, 15-25g / L sodium hypophosphite, 40-60mg / L dimethylamino borane, 15-30g / L complexing agent, 10-20mg / L stabilizer, 0.5-1.5mg / L accelerator, 0.5-1.5g / L metal ion salt, and 200-300mg / L anionic surfactant.

[0007] In a preferred embodiment of the present invention, the complexing agent is at least one of ethylenediaminetetraacetic acid, potassium sodium tartrate and sodium citrate.

[0008] In a preferred embodiment of the present invention, the stabilizer is at least one of potassium ferrocyanide and sodium diphenylamine sulfonate.

[0009] In a preferred embodiment of the present invention, the accelerator is L-arginine.

[0010] In a preferred embodiment of the present invention, the metal ion salt is nickel sulfate.

[0011] In a preferred embodiment of the present invention, the pH value of the chemical copper plating solution is adjusted to 8-10 by adding an alkaline solution.

[0012] More preferably, the alkaline solution is aqueous ammonia.

[0013] In a preferred embodiment of the present invention, the chemical copper plating solution is used at a temperature of 60-70°C.

[0014] In order to achieve the above purpose, the second technical solution of the present invention is: application of the above-mentioned double reducing agent chemical copper plating solution in PET copper plating.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The double reducing agent chemical copper plating solution of the invention can reduce the production cost of the composite copper foil, reduce the resistivity of the copper plating layer, increase the bonding force between the PET and the copper plating layer, and increase the copper plating speed of the chemical copper plating solution. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is described in more detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to these embodiments.

[0018] A double reducing agent chemical copper plating solution suitable for PET copper plating, comprising: 6-10 g / L copper sulfate, 15-25 g / L sodium hypophosphite, 40-60 mg / L dimethylamino borane, 15-30 g / L complexing agent, 10-20 mg / L stabilizer, 0.5-1.5 mg / L accelerator, 0.5-1.5 g / L metal ion salt, and 200-300 mg / L anionic surfactant.

[0019] The complexing agent is at least one of ethylenediaminetetraacetic acid, potassium sodium tartrate and sodium citrate.

[0020] The stabilizer is at least one of potassium ferrocyanide and sodium diphenylamine sulfonate.

[0021] The accelerator is L-arginine.

[0022] The metal ion salt is nickel sulfate.

[0023] The pH value of the chemical copper plating solution is adjusted to 8-10 by adding an alkaline solution.

[0024] The alkaline solution is aqueous ammonia.

[0025] The chemical copper plating solution is used at a temperature of 60-70°C.

[0026] Application of the above-mentioned double reducing agent chemical copper plating solution in PET copper plating.

[0027] Example 1

[0028] A double reducing agent chemical copper plating solution suitable for PET copper plating, each liter of chemical copper plating solution contains the following components:

[0029] Copper sulfate 8g, sodium hypophosphite 20g, dimethylamino borane 50mg, complexing agent ethylenediaminetetraacetic acid 20g, stabilizer 12mg (including sodium diphenylamine sulfonate 10mg, potassium ferrocyanide 2mg), accelerator L-arginine 1mg, metal ion salt nickel sulfate 1g, anionic surfactant polyethylene glycol 250mg.

[0030] The above components were added with deionized water to make up to 1 L, and 25 wt% alkaline ammonia solution was added to adjust the pH value to 9. The mixture was heated to 65° C. when used.

[0031] Example 2

[0032] A double reducing agent chemical copper plating solution suitable for PET copper plating, each liter of chemical copper plating solution contains the following components:

[0033] Copper sulfate 8g, sodium hypophosphite 20g, dimethylamino borane 50mg, complexing agent 25g (including ethylenediaminetetraacetic acid 20g, potassium sodium tartrate 5g), stabilizer 15mg (including sodium diphenylamine sulfonate 10mg, potassium ferrocyanide 5mg), accelerator L-arginine 1mg, metal ion salt nickel sulfate 1g, anionic surfactant polyethylene glycol 250mg.

[0034] The above components were added with deionized water to make up to 1 L, and 25 wt% alkaline ammonia solution was added to adjust the pH value to 9. The mixture was heated to 65° C. when used.

[0035] Example 3

[0036] A double reducing agent chemical copper plating solution suitable for PET copper plating, each liter of chemical copper plating solution contains the following components:

[0037] Copper sulfate 8g, sodium hypophosphite 20g, dimethylamino borane 50mg, complexing agent 25g (including ethylenediaminetetraacetic acid 20g, sodium citrate 5g), stabilizer 15mg (including sodium diphenylamine sulfonate 10mg, potassium ferrocyanide 5mg), accelerator L-arginine 1mg, metal ion salt nickel sulfate 1g, anionic surfactant polyethylene glycol 250mg.

[0038] The above components were added with deionized water to make up to 1 L, and 25 wt% alkaline ammonia solution was added to adjust the pH value to 9. The mixture was heated to 65° C. when used.

[0039] Comparative Example 1

[0040] A chemical copper plating solution, each liter of the chemical copper plating solution contains the following components:

[0041] Copper sulfate 8g, sodium hypophosphite 20g, ethylenediaminetetraacetic acid 20g, potassium sodium tartrate 5g, sodium diphenylamine sulfonate 10mg, potassium ferrocyanide 5mg, L-arginine 1mg, nickel sulfate 1g, polyethylene glycol 250mg.

[0042] The above components were added with deionized water to make up to 1 L, and 25 wt% alkaline ammonia solution was added to adjust the pH value to 9. The mixture was heated to 65° C. when used.

[0043] Comparative Example 2

[0044] A chemical copper plating solution, each liter of the chemical copper plating solution contains the following components:

[0045] Copper sulfate 8g, sodium hypophosphite 20g, dimethylaminoborane 50mg, ethylenediaminetetraacetic acid 20g, potassium sodium tartrate 5g, potassium ferrocyanide 5mg, L-arginine 1mg, nickel sulfate 1g, polyethylene glycol 250mg.

[0046] The above components were added with deionized water to make up to 1 L, and 25 wt% alkaline ammonia solution was added to adjust the pH value to 9. The mixture was heated to 65° C. when used.

[0047] The copper deposition rate and copper deposition bonding strength of the chemical copper plating solutions of Examples 1-3 and Comparative Examples 1-2 on PET were tested according to the following method. The test results are shown in Table 1.

[0048] (1) Copper deposition rate test

[0049] a Cut a PET area (S) of about 40mm×60mm and lightly sand it;

[0050] b. Place the polished PET in an ethanol solution and perform ultrasound for 10 minutes;

[0051] c. Degreasing: Put the PET into the degreasing solution for degreasing at 65°C for 15 minutes;

[0052] d Roughening: The deoiled PET is placed in a roughening solution for roughening (the roughening solution contains potassium permanganate and sodium hydroxide) at 65°C for 10 minutes; the roughened PET is dried and cooled to room temperature and then weighed (accurate to 0.0001g), and the weight is recorded and calculated as W1;

[0053] e Sensitization: The roughened PET was immersed in the sensitization solution for 5 minutes, the time was 5 minutes, and the temperature was room temperature;

[0054] f Activation: The sensitized PET is placed in palladium chloride activation solution for activation for 5 minutes at room temperature;

[0055] g. Immerse the activated PET in the chemical copper plating solution for 10 minutes, then rinse it with water, blow it dry with a fan, and then put it in a drying oven at 60°C for 5 hours; place the dried board in a dryer to cool it to room temperature and weigh it (accurate to 0.0001g), and the weight is calculated as W2;

[0056] h Copper deposition rate thickness calculation: [(W2-W1)÷(8.96×S×2)]×10000.

[0057] After each of the above steps, multiple water washing is required to prevent impurities from contaminating the chemical copper plating solution.

[0058] (2) Copper deposition bonding strength test

[0059] The bonding strength was tested by using the tape bonding method and the rubbing method. The dried PET was bonded with tape, rubbed with a 100g weight, and then torn to observe the amount of copper attached to the tape. Finally, the tape was rubbed to observe the amount of copper falling off the PET surface.

[0060] Table 1 Test results of copper deposition rate and copper deposition bonding strength of chemical copper plating solutions of Examples 1-3 and Comparative Examples 1-2

[0061]

[0062] From the test results of Table 1, it can be seen that the deposition rates of the chemical copper plating solutions of Examples 1-3 on the PET surface are relatively high, which are 1.8μm / h, 1.4μm / h, and 1.5μm / h, respectively, and the copper deposition bonding strength is good. In Comparative Example 1, there is no copper deposition on the PET surface. Although the deposition rate of Comparative Example 2 is 2.0μm / h, its bonding strength is very poor, and a large amount of shedding occurs. Comparing the results of Example 2 and Comparative Example 1, it can be seen that the use of dimethylamine borane can help the copper plating solution with ethylenediaminetetraacetic acid as the main complexing agent to deposit copper; the reference example 2 and some components of Comparative Example 2 show that sodium diphenylamine sulfonate can enhance the copper plating bonding strength, thereby improving the copper plating quality. In addition, it can be seen from the resistivity test results that the resistivity of Example 2 is the smallest, indicating that potassium sodium tartrate and sodium diphenylamine sulfonate can refine the grain size of copper, thereby reducing the resistivity.

[0063] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A double reducing agent chemical copper plating solution suitable for PET copper plating, characterized in that: Its components include 6-10 g / L of copper sulfate, 15-25 g / L of sodium hypophosphite, 40-60 mg / L of dimethylamino borane, 15-30 g / L of complexing agent, 10-20 mg / L of stabilizer, 0.5-1.5 mg / L of accelerator, 0.5-1.5 g / L of metal ion salt and 200-300 mg / L of anionic surfactant.

2. The double reducing agent chemical copper plating solution according to claim 1, characterized in that: The complexing agent is at least one of ethylenediaminetetraacetic acid, potassium sodium tartrate and sodium citrate.

3. The double reducing agent chemical copper plating solution according to claim 1, characterized in that: The stabilizer is at least one of potassium ferrocyanide and sodium diphenylamine sulfonate.

4. The double reducing agent chemical copper plating solution according to claim 1, characterized in that: The accelerator is L-arginine.

5. The double reducing agent chemical copper plating solution according to claim 1, characterized in that: The metal ion salt is nickel sulfate.

6. The double reducing agent chemical copper plating solution according to claim 1, characterized in that: The pH value of the chemical copper plating solution is adjusted to 8-10 by adding an alkaline solution.

7. The double reducing agent chemical copper plating solution according to claim 1, characterized in that: The alkaline solution is aqueous ammonia.

8. The double reducing agent chemical copper plating solution according to claim 1, characterized in that: The chemical copper plating solution is used at a temperature of 60-70°C.

9. Use of the double reducing agent chemical copper plating solution according to any one of claims 1 to 8 in PET copper plating.

Images