Method for improving color of gold surface of PCB and gold-plated product

Abstract

The invention discloses a method for improving the color of a gold surface of a PCB and a gold-plated product, and relates to the field of electroplating, and the method comprises the following steps: S1, mixing pyridine, organic acid, potassium oxalate and water, and adjusting the pH value to 4-6 to obtain an electroplating solution; s2, immersing the electroplated part into an electroplating solution, and carrying out electroplating treatment for 5-30 minutes; and S3, the electroplated part is taken out, washed with clear water and dried. The application has the effect of improving the color of the gold surface of the PCB and the gold-plated product.

Description

Technical Field

[0001] The invention relates to the field of electroplating, and in particular to a method for improving the gold surface color of PCB and gold-plated products. Background Art

[0002] With the trend of miniaturization and high performance of electronic products, the requirements for the surface quality of PCBs and gold-plated products are increasing. At present, the gold surface color of PCBs and gold-plated products is affected by many factors, the two most important of which are the substrate material and the composition of the plating solution.

[0003] Traditional gold plating processes often focus on improving the thickness of the gold layer and its conductivity, lack effective color adjustment ingredients, and ignore the consistency and brightness of the color, resulting in uneven appearance quality of the finished products and affecting market competitiveness.

[0004] Therefore, as consumers' requirements for the appearance quality of electronic products continue to increase, the industry urgently needs to develop a new process that can not only ensure the good color of the electroplated gold layer but also take into account economic benefits. Summary of the invention

[0005] In order to improve the gold surface color of PCB and gold-plated products, the present application provides a method for improving the gold surface color of PCB and gold-plated products.

[0006] The present application provides a method for improving the surface color of PCB and gold-plated products using the following technical solutions: A method for improving the gold surface color of PCB and gold-plated products, comprising the following steps: S1. Mix pyridine, an organic acid, potassium oxalate and water, and adjust the pH to 4-6 to obtain a plating solution; S2. Immerse the electroplated part in the electroplating solution and perform electroplating for 5-30 minutes; S3. Take out the electroplated parts, rinse them with clean water and dry them.

[0007] By adopting the above technical solution, the present application adds pyridine and organic acid to the electroplating solution, which can promote the uniform deposition of gold particles on the substrate. The unique conjugated system of the pyridine molecular structure gives the metal coating a better gloss, making the color fuller and more stable.

[0008] Preferably, in step S1, the concentration of pyridine is 5-30 g / L; the concentration of potassium oxalate is 50-100 g / L; and the concentration of the organic acid is 15-25 g / L.

[0009] By adopting the above technical solution, the concentration of each component in the electroplating solution defined in the present application will increase the current efficiency and metal deposition rate, improve the dispersion ability of the coating, and make the coating thickness distribution more uniform.

[0010] Preferably, in step S2, the current density during the electroplating process is 1-1.5 A / dm 2 .

[0011] By adopting the above technical solution and setting a good current density, the formation of the coating can be accelerated, the crystallinity of the coating can be increased, the grain size can be reduced, and the hardness and wear resistance of the coating can be improved.

[0012] Preferably, in step S2, ultrasonic vibration is set during the electroplating process, the frequency of the ultrasonic vibration is 30-50 kHz, and the ultrasonic time is 10-15 min.

[0013] By adopting the above technical solution, ultrasonic vibration is used in the electroplating process to optimize the coating structure at the micro level, significantly improve the visual appearance, and help extend the service life of the coating, meeting the requirements of electronic products for high performance and long life; prevent particle deposition, ensure that the coating is delicate and smooth, further promote the uniform distribution of gold particles, and enhance the depth and saturation of the color of the gold-plated surface.

[0014] Preferably, in step S2, the temperature of the electroplating treatment is 50-60°C.

[0015] By adopting the above technical solution and controlling the temperature during the electroplating process, the conductivity of the electrolyte can be increased, and the diffusion rate of ions can be promoted, thereby improving the electroplating efficiency and deposition rate, so that the electroplated parts can obtain a delicate coating structure.

[0016] Preferably, the organic acid is acetic acid.

[0017] By adopting the above technical solution, the selection of acetic acid can help maintain the stability of the electroplating solution, thereby improving the crystallization fineness and brightness of the coating.

[0018] Preferably, the concentration ratio of pyridine to potassium oxalate is 1:(6.5-7.5).

[0019] By adopting the above technical solution, when the concentration ratio of pyridine and potassium oxalate is at a specific ratio, the brightness and consistency of the gold surface color of PCB and gold-plated products are significantly enhanced, thereby improving the appearance quality of the product.

[0020] Preferably, the electroplating solution comprises the following raw materials in parts by weight: 10-20 parts by weight of nickel sulfate.

[0021] By adopting the above technical solution, nickel sulfate is added to the electrolyte to provide ions for electrodeposited metals. Nickel sulfate can assist in forming fine crystals on the surface of the electroplated parts, further improving the aesthetics of the coating.

[0022] Preferably, the electroplating treatment time is 10-15 minutes.

[0023] By adopting the above technical solution, setting a better electroplating treatment time can ensure that the coating has good crystal structure and physical properties. Too short an electroplating time may cause the coating to be loose and uneven, while too long a time may cause the coating to be too thick, or even produce cracks or other defects.

[0024] In summary, this application has the following beneficial technical effects: 1. The present application adds pyridine and organic acid to the electroplating solution, which can promote the uniform deposition of gold particles on the substrate. The unique conjugated system of the pyridine molecular structure gives the metal coating a better gloss, making the color fuller and more stable.

[0025] 2. The concentration of each component in the electroplating solution specified in this application will increase the current efficiency and metal deposition rate, improve the dispersion ability of the coating, and make the coating thickness distribution more uniform.

[0026] 3. Ultrasonic vibration is used in the electroplating process to optimize the coating structure at the microscopic level, significantly improve the visual perception, and help extend the service life of the coating, meeting the requirements of electronic products for high performance and long life; prevent particle deposition, ensure the coating is delicate and smooth, further promote the uniform distribution of gold particles, and enhance the depth and saturation of the color of the gold-plated surface. DETAILED DESCRIPTION

[0027] The present application is further described in detail below with reference to examples and comparative examples. Example

[0028] Example 1 A method for improving the gold surface color of PCB and gold-plated products, comprising the following steps: S1. Mix 20g of pyridine, 40g of organic acid, 40g of potassium oxalate and 100g of water and stir for 1 min, adjust the pH to 4, and obtain an electroplating solution; wherein the concentration of pyridine is 5g / L, the organic acid is acetic acid, and the concentration is 15g / L; the concentration of potassium oxalate is 50g / L.

[0029] S2. Immerse the electroplated part in the electroplating solution and perform electroplating for 5 minutes at a temperature of 50°C; the current density is 1A / dm 2 .

[0030] S3. Take out the electroplated parts, rinse them with clean water, and dry them at a temperature of 80°C.

[0031] Example 2 A method for improving the gold surface color of PCB and gold-plated products, comprising the following steps: S1. Mix 20g of pyridine, 40g of organic acid, 40g of potassium oxalate and 100g of water and stir for 1 min, adjust the pH to 6, and obtain an electroplating solution; wherein the concentration of pyridine is 30g / L, the organic acid is acetic acid, and the concentration is 25g / L; the concentration of potassium oxalate is 100g / L.

[0032] S2. Immerse the electroplated part in the electroplating solution and perform electroplating for 30 minutes at a temperature of 60°C; the current density is 1.5A / dm 2 .

[0033] S3. Take out the electroplated parts, rinse them with clean water, and dry them at a temperature of 80°C.

[0034] Example 3 A method for improving the gold surface color of PCB and gold-plated products, comprising the following steps: S1. Mix 20g of pyridine, 40g of organic acid, 40g of potassium oxalate and 100g of water and stir for 1 min, adjust the pH to 4, and obtain an electroplating solution; wherein the concentration of pyridine is 20g / L, the organic acid is acetic acid, and the concentration is 20g / L; the concentration of potassium oxalate is 75g / L.

[0035] S2. Immerse the electroplated part in the electroplating solution and perform electroplating for 20 minutes at a temperature of 55°C; the current density is 1.2A / dm 2 .

[0036] S3. Take out the electroplated parts, rinse them with clean water, and dry them at a temperature of 80°C.

[0037] Example 4 A method for improving the gold surface color of PCB and gold-plated products, which is different from Example 3 in that: during the process of preparing the electroplating solution in step S1, 10g of nickel sulfate is also added.

[0038] Example 5 A method for improving the gold surface color of PCB and gold-plated products, which is different from Example 3 in that: during the process of preparing the electroplating solution in step S1, 20g of nickel sulfate is also added.

[0039] Example 6 A method for improving the gold surface color of PCB and gold-plated products, which is different from Example 5 in that: in the process of preparing the electroplating solution in step S1, the concentration of pyridine is 10g / L and the concentration of potassium oxalate is 65g / L.

[0040] Example 7 A method for improving the gold surface color of PCB and gold-plated products, which is different from Example 5 in that: in the process of preparing the electroplating solution in step S1, the concentration of pyridine is 10g / L and the concentration of potassium oxalate is 75g / L.

[0041] Example 8 A method for improving the gold surface color of PCB and gold-plated products, which is different from Example 7 in that: during the electroplating process in step S2, ultrasonic vibration with a frequency of 30 kHz is applied.

[0042] Example 9 A method for improving the gold surface color of PCB and gold-plated products, which is different from Example 7 in that: during the electroplating process in step S2, ultrasonic vibration with a frequency of 50 kHz is applied.

[0043] Example 10 A method for improving the gold surface color of PCB and gold-plated products, which is different from Example 7 in that: during the electroplating process in step S2, ultrasonic vibration with a frequency of 80 kHz is applied.

[0044] Embodiment 11 A method for improving the gold surface color of PCB and gold-plated products, which is different from Example 9 in that: during the electroplating process in step S2, the current density is 1.3A / dm 2 , the electroplating time was 12 min, and the ultrasonic frequency was 35 kHz.

[0045] Comparative Example Comparative Example 1 A method for improving the gold surface color of PCB and gold-plated products, which is different from Example 3 in that pyridine is not added.

[0046] Comparative Example 2 A method for improving the gold surface color of PCB and gold-plated products, which is different from Example 3 in that an equal amount of potassium oxalate is replaced by sodium sulfate.

[0047] Comparative Example 3 A method for improving the gold surface color of PCB and gold-plated products, which is different from Example 3 in that an equal amount of pyridine is replaced by furan.

[0048] Comparative Example 4 A method for improving the gold surface color of PCB and gold-plated products, which is different from Example 3 in that: in step S2, the electroplating treatment time is 60 minutes.

[0049] Comparative Example 5 A method for improving the gold surface color of PCB and gold-plated products, which is different from Example 5 in that an equal amount of pyridine is replaced by pyrimidine.

[0050] Performance testing: Color stability: The surfaces of the plated layers of the electroplated parts prepared in Examples 1-11 and Comparative Examples 1-5 were visually measured and scored.

[0051] Adhesion: The electroplated parts prepared in Examples 1-11 and Comparative Examples 1-5 were measured with reference to GB / T9286.

[0052] Heat resistance: The electroplated parts prepared in Examples 1-11 and Comparative Examples 1-5 were baked at 200° C. for 30 minutes, and the color change and peeling phenomena were observed. Color stability score Adhesion Heat resistance Example 1 92 Level 1 No peeling, slight cracking Example 2 92 Level 1 No peeling, slight cracking Example 3 95 Level 1 No peeling, slight cracking Example 4 96 Level 0 No peeling or cracking Example 5 96 Level 0 No peeling or cracking Example 6 97 Level 0 No peeling or cracking Example 7 97 Level 0 No peeling or cracking Example 8 98 Level 0 No peeling or cracking Example 9 98 Level 0 No peeling or cracking Example 10 88 Level 1 Slight peeling around Embodiment 11 99 Level 0 No peeling or cracking Comparative Example 1 77 Level 2 Slight peeling around Comparative Example 2 85 Level 1 Slight peeling around Comparative Example 3 83 Level 1 Slight peeling around Comparative Example 4 82 Level 3 Slight peeling around Comparative Example 5 81 Level 2 Slight peeling around

[0053] According to the data comparison of Examples 1-3 and Comparative Examples 1-5, the addition of pyridine and organic acid to the electroplating solution can promote the uniform deposition of gold particles on the substrate, and the unique conjugated system of the pyridine molecular structure gives the metal coating a better gloss, making the color fuller and more stable.

[0054] According to the data comparison of Examples 3-5, it can be obtained that adding nickel sulfate in the electrolyte provides ions for electrodeposited metals. Nickel sulfate can assist in forming fine crystals on the surface of the electroplated parts, further improving the aesthetics of the coating.

[0055] According to the data comparison of Examples 5-7, when the concentration ratio of pyridine and potassium oxalate is at a specific ratio, the brightness and consistency of the gold surface color of PCB and gold-plated products are significantly enhanced, thereby improving the appearance quality of the products.

[0056] According to the data comparison of Examples 7-10, ultrasonic vibration is used in the electroplating process to optimize the coating structure at the microscopic level, significantly improve the visual perception, and help extend the service life of the coating, meeting the requirements of electronic products for high performance and long life; prevent particle deposition, ensure that the coating is delicate and smooth, further promote the uniform distribution of gold particles, and enhance the depth and saturation of the color of the gold-plated surface.

[0057] According to the data comparison of Example 9 and Example 11, it can be obtained that setting a good current density can accelerate the formation of the coating, increase the crystallinity of the coating, reduce the grain size, and improve the hardness and wear resistance of the coating.

Claims

1. A method for improving the gold surface color of PCB and gold-plated products, characterized in that: The following steps are involved: S1. Mix pyridine, an organic acid, potassium oxalate and water, and adjust the pH to 4-6 to obtain a plating solution; S2. Immerse the electroplated part in the electroplating solution and perform electroplating for 5-30 minutes; S3. Take out the electroplated parts, rinse them with clean water and dry them.

2. The method for improving the gold surface color of PCB and gold-plated products according to claim 1, characterized in that: In step S1, the concentration of pyridine is 5-30 g / L; the concentration of potassium oxalate is 50-100 g / L; and the concentration of the organic acid is 15-25 g / L.

3. The method for improving the gold surface color of PCB and gold-plated products according to claim 1, characterized in that: In step S2, the current density during the electroplating process is 1-1.5A / dm².

4. The method for improving the gold surface color of PCB and gold-plated products according to claim 1, characterized in that: In step S2, ultrasonic vibration is set during the electroplating process, the frequency of the ultrasonic vibration is 30-50 kHz, and the ultrasonic time is 10-15 minutes.

5. The method for improving the gold surface color of PCB and gold-plated products according to claim 1, characterized in that: In step S2, the temperature of the electroplating treatment is 50-60°C.

6. The method for improving the gold surface color of PCB and gold-plated products according to claim 1, characterized in that: The organic acid is acetic acid.

7. The method for improving the gold surface color of PCB and gold-plated products according to claim 1, characterized in that: The concentration ratio of pyridine to potassium oxalate is 1:(6.5-7.5).

8. The method for improving the gold surface color of PCB and gold-plated products according to claim 1, characterized in that: The electroplating solution comprises the following raw materials in parts by weight: 10-20 parts by weight of nickel sulfate.

9. The method for improving the gold surface color of PCB and gold-plated products according to claim 1, characterized in that: The electroplating treatment time is 10-15 minutes.