Environment-friendly cyanide-free electroplating process

Abstract

The invention relates to an environment-friendly cyanide-free electroplating process which is simple and exquisite in step and easy to control, and each step is carefully and finely. The surface layer of the plating piece is cleaned up through the plating piece cleaning step, the plating piece is soaked in micro-etching liquid through the plating piece surface micro-etching step, the micro-etching liquid conducts micro-etching treatment on the surface of the plating piece, and therefore the surface of the plating piece is roughened. Pre-plating treatment is carried out on the surface of the plating piece through the plating piece surface first-time washing step and the plating piece pre-plating step, and a pre-plating layer is generated on the surface of the plating piece. The surface of the plating piece is electroplated through the second washing step of the surface of the plating piece and the electroplating step of the plating piece. And the electroplated part is subjected to blow-drying treatment through the step of air drying of the electroplated part. The environment-friendly cyanide-free electroplating process is environment-friendly, non-toxic, high in electroplating efficiency and good in stability, and a plating layer produced on a plated part is good in compactness and uniformity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of cyanide-free electroplating, in particular to an environmentally friendly cyanide-free electroplating process. BACKGROUND

[0002] Electroplating is a process of plating a thin film of other metals or alloys on the surface of certain metals by using electrolysis. It is a process of attaching a metal film to the surface of metal or other material parts by using electrolysis, thereby preventing metal oxidation, improving wear resistance, electrical conductivity, reflectivity, corrosion resistance, and aesthetics. The outer layer of many coins is also electroplated. During electroplating, the plating metal or other insoluble material serves as the anode, and the workpiece to be plated serves as the cathode. The cations of the plating metal are reduced on the surface of the workpiece to be plated to form a plating layer. To exclude the interference of other cations and ensure uniform and firm plating, a solution containing the cations of the plating metal is used as the electroplating solution to maintain the concentration of the cations of the plating metal unchanged. The purpose of electroplating is to plate a metal layer on the substrate.

[0003] However, cyanide-free electroplating refers to a new electroplating process that uses non-cyanide electrolyte instead of toxic cyanide electrolyte. Widely used in production are pyrophosphate copper plating, ammonium salt zinc plating, zincate zinc plating, pyrophosphate zinc plating, and nickel-iron ternary alloy plating. Cyanide-free electroplating can avoid worker poisoning and environmental pollution. Traditional cyanide-free electroplating processes, such as the patent with the application number CN202111243386.5 and the invention name of cyanide-free gold plating solution and its application, electroplating method for gold bump, and gold bump and electronic component, have low electroplating efficiency and low stability. SUMMARY

[0004] Therefore, it is necessary to provide an environmentally friendly cyanide-free electroplating process to solve the technical problems of low electroplating efficiency and low stability of traditional cyanide-free electroplating processes.

[0005] An environmentally friendly cyanide-free electroplating process, which comprises the following steps: A plating part cleaning step: cleaning the surface layer of the plating part; A plating part surface micro-etching step: soaking the plating part in a micro-etching solution; A first plating part surface rinsing step: rinsing the micro-etching solution on the surface layer of the plating part clean; A plating part pre-plating step: soaking the plating part in a pre-plating solution; A second plating part surface rinsing step: rinsing the pre-plating solution on the surface layer of the plating part clean; The plating piece is subjected to electroplating treatment, and the electroplating solution comprises the following components: cuprous sulfate 20 g / L to 30 g / L, cuprous chloride 10 g / L to 20 g / L, dithiooxamide 20 g / L to 40 g / L, hydroxyethylidene diphosphonic acid 10 g / L to 20 g / L, ethylenediamine 2 g / L to 10 g / L, sodium tartrate 4 g / L to 12 g / L, sodium methylsulfonate 5 g / L to 10 g / L, polyethylene glycol 30 mg / L to 60 mg / L, polyvinyl alcohol 0.5 g / L to 1 g / L, and polyethylene oxide 0.2 g / L to 0.5 g / L; The plating piece is subjected to air drying treatment after electroplating.

[0006] In one of the embodiments, in the plating piece surface etching step, the etching solution comprises: hydrogen peroxide 40 mg / L to 60 mg / L, sulfuric acid 30 mg / L to 90 mg / L, sodium persulfate 20 mg / L to 30 mg / L, sodium chloride 100 mg / L to 200 mg / L, tartaric acid 3 g / L to 6 g / L, diethylene glycol methyl ether 2 g / L to 4 g / L, and dibenzotriazole 4 g / L to 8 g / L.

[0007] In one of the embodiments, in the plating piece surface etching step, the soaking time is 1 minute to 2 minutes, and the temperature of the etching solution is 35 degrees Celsius to 45 degrees Celsius.

[0008] In one of the embodiments, in the plating piece pre-plating step, the pre-plating solution comprises the following components by mass: anhydrous copper sulfate 2 g / L to 4 g / L, copper chloride 2 g / L to 5 g / L, copper nitrate 3 g / L to 6 g / L, methanol 4 g / L to 8 g / L, sodium dodecyl benzene sulfonate 1 g / L to 2 g / L, triethanolamine 1 g / L to 2 g / L, sodium hypophosphite 12 g / L to 40 g / L, and citric acid 4 g / L to 8 g / L.

[0009] In one of the embodiments, the temperature of the pre-plating solution is 45 degrees Celsius to 55 degrees Celsius, and the soaking time is 2 minutes to 5 minutes.

[0010] In one of the embodiments, in the plating piece electroplating step, the electroplating solution further comprises a stabilizer 30 mg / L to 50 mg / L, and the stabilizer is 6-maleic acid nitroquinolizine salt.

[0011] In one of the embodiments, in the plating piece electroplating step, the electroplating solution further comprises a brightener 8 g / L to 20 g / L, and the brightener is a mixture of antimony sulfate and antimony nitrate.

[0012] In one of the embodiments, in the plating step, the plating solution further comprises a surfactant at 20-30 mg / L, and the surfactant is an allyloxy polyoxyethylene ether.

[0013] In one of the embodiments, in the plating step, the cathode current density is 25-35 A / dm 2 . 2 .

[0014] In one of the embodiments, in the plating step, the temperature of the plating solution is 50-80 degrees Celsius.

[0015] The above-mentioned environmental protection non-cyanide plating process steps are concise and ingenious, easy to control, and each step is careful and meticulous. Through the plating part cleaning step, the surface of the plating part is cleaned, through the plating part surface micro-etching step, the plating part is soaked in the micro-etching solution, so that the micro-etching solution performs micro-etching treatment on the surface of the plating part, thereby roughening the surface of the plating part. Through the first rinsing step and the plating part pre-plating step, pre-plating treatment is performed on the surface of the plating part to generate a pre-plating layer. Through the second rinsing step and the plating step, the surface of the plating part is plated. Through the plating part air-drying step, the plated plating part is blow-dried. The above-mentioned environmental protection non-cyanide plating process is environmentally friendly, non-toxic, high in plating efficiency, good in stability, good in compactness and uniformity of the plating layer in the production of the plating part. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a flowchart of the environmental protection non-cyanide plating process in one of the embodiments. DETAILED DESCRIPTION

[0017] In order to make the above-mentioned objects, features and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application are described in detail below in combination with the drawings. In the following description, a large number of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the scope of the present application, so the present application is not limited to the specific embodiments disclosed below. In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0018] In addition, the terms "first", "second", etc. are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or an ordered sequence. Thus, features referring to "first", "second" etc. can include at least one of the features, explicitly or implicitly.

[0019] In the present application, unless specifically defined otherwise, the terms "mounting", "connecting", "connecting", "fixing" and the like are to be construed broadly, for example, can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically defined. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0020] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0021] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there can be a mediating element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or there can be a mediating element. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation.

[0022] Please refer to Figure 1 The present application provides an environmentally friendly cyanide-free electroplating process, which comprises the following steps: Step 101: plating part cleaning step: clean the surface layer of the plating part.

[0023] Specifically, first, the floating dust and impurities on the surface layer of the plating part are cleaned with pure water, then the oxide layer on the surface layer of the plating part is cleaned with pickling solution, and finally the oil stains on the surface layer of the plating part are removed with degreasing solution.

[0024] Step 102: surface micro-etching step: immerse the plated part in a micro-etching solution.

[0025] Specifically, the plated part is immersed in the micro-etching solution for 1-2 minutes at a temperature of 35-45°C. The micro-etching solution comprises 40-60 mg / L of hydrogen peroxide, 30-90 mg / L of sulfuric acid, 20-30 mg / L of sodium persulfate, 100-200 mg / L of sodium chloride, 3-6 g / L of tartaric acid, 2-4 g / L of diethylene glycol methyl ether, and 4-8 g / L of benzotriazole. The micro-etching solution comprising the above components can ensure micro-etching of the plated part surface, roughening the plated part surface while avoiding excessive corrosion of the plated part surface.

[0026] Step 103: first rinsing step: rinse the micro-etching solution on the surface of the plated part.

[0027] Specifically, the micro-etching solution on the surface of the plated part is rinsed clean using pure water. Step 104: pre-plating step: immerse the plated part in a pre-plating solution.

[0028] Specifically, the plated part is immersed in the pre-plating solution. The pre-plating solution has a temperature of 45-55°C and is immersed for 2-5 minutes. In this embodiment, the pre-plating solution comprises the following components by mass: 2-4 g / L of anhydrous copper sulfate, 2-5 g / L of copper chloride, 3-6 g / L of copper nitrate, 4-8 g / L of methanol, 1-2 g / L of sodium dodecyl benzene sulfonate, 1-2 g / L of triethanolamine, 12-40 g / L of sodium hypophosphite, and 4-8 g / L of citric acid. The pre-plating solution comprising the above components can form a thin copper layer on the surface of the plated part, increasing the stability of the combination between the electroplated layer formed in the later electroplating step and the plated part.

[0029] Step 105: second rinsing step: rinse the pre-plating solution on the surface of the plated part.

[0030] Specifically, the pre-plating solution on the surface of the plated part is rinsed clean using pure water.

[0031] Step 106: plating step: the plating piece is subjected to plating treatment, the plating solution comprises the following components: cuprous sulfate 20 g / L to 30 g / L, cuprous chloride 10 g / L to 20 g / L, dithiooxamide 20 g / L to 40 g / L, hydroxyethylidene diphosphonic acid 10 g / L to 20 g / L, ethylenediamine 2 g / L to 10 g / L, sodium tartrate 4 g / L to 12 g / L, sodium methylsulfonate 5 g / L to 10 g / L, polyethylene glycol 30 mg / L to 60 mg / L, polyvinyl alcohol 0.5 g / L to 1 g / L, and polyethylene oxide 0.2 g / L to 0.5 g / L. The cathode current density is 25 A / dm 2 to 35 A / dm 2 The temperature of the plating solution is 50 degrees Celsius to 80 degrees Celsius. The plating solution composed of the above components can quickly form a dense plating layer on the surface layer of the plating piece.

[0032] Step 107: air drying step of the plating piece: the plating piece after plating is subjected to air drying treatment.

[0033] Specifically, the plating piece after plating is subjected to air drying treatment with a hot air blower.

[0034] In order to increase the stability and efficiency of the plating process, in one embodiment, in the plating step of the plating piece, the plating solution further comprises a stabilizer 30 mg / L to 50 mg / L, and the stabilizer is 6-maleic acid nitroquinolizine salt. The 6-maleic acid nitroquinolizine salt can ensure the stable progress of the plating process while improving the plating rate.

[0035] In order to increase the gloss of the plating layer formed on the surface layer of the plating piece during plating operation, in one embodiment, in the plating step of the plating piece, the plating solution further comprises a brightener 8 g / L to 20 g / L, and the brightener is a mixture of antimony sulfate and antimony nitrate. Antimony sulfate and antimony nitrate can increase the gloss of the plating layer formed on the surface layer of the plating piece during plating operation.

[0036] In order to increase the uniformity of the plating layer formed on the surface layer of the plating piece during plating operation, in one embodiment, in the plating step of the plating piece, the plating solution further comprises a surfactant 20 mg / L to 30 mg / L, and the surfactant is allyloxy polyoxyethylene ether. Allyloxy polyoxyethylene ether can reduce the surface tension of the plating solution, enhance the wettability, make the plating solution uniformly cover the surface of the plating piece, and reduce the defects of the plating layer caused by air bubbles. On the other hand, it can make the pits on the surface layer of the plating piece preferentially undergo plating deposition, thereby ensuring the flatness of the plating layer.

[0037] The above-mentioned environmental protection non-cyanide electroplating process steps are simple, easy to control, and each step is careful and meticulous. The surface of the plated part is cleaned through the plated part cleaning step, the plated part is immersed in the micro-etching liquid through the plated part surface micro-etching step, the micro-etching liquid is used for micro-etching treatment on the surface of the plated part, so as to roughen the surface of the plated part. The plated part surface is pre-plated through the first plated part surface rinsing step and the plated part pre-plating step, and a pre-plating layer is generated on the surface of the plated part. The plated part surface is electroplated through the second plated part surface rinsing step and the plated part electroplating step. The plated part is blown dry after electroplating through the plated part air-drying step. The above-mentioned environmental protection non-cyanide electroplating process is environmental protection and non-toxic, has high electroplating efficiency, good stability, good compactness and uniformity of the plated layer in the production of the plated part.

[0038] The technical features of the above-mentioned embodiments can be combined in any manner. In order to make the description simple, all possible combinations of the technical features in the above-mentioned embodiments are not described, however, as long as the combinations of the technical features do not contradict each other, they should be considered as the scope of the present application.

[0039] The above-mentioned embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of the present application. Therefore, the scope of the patent of the present application should be subject to the appended claims.

Claims

1. An environmentally friendly cyanide-free electroplating process, characterized by, The process comprises the following steps: A plating part cleaning step: clean the surface layer of the plating part; A plating part surface micro-etching step: immerse the plating part in a micro-etching solution; A first plating part surface rinsing step: rinse the micro-etching solution on the surface layer of the plating part; A plating part pre-plating step: immerse the plating part in a pre-plating solution; A second plating part surface rinsing step: rinse the pre-plating solution on the surface layer of the plating part; A plating part electroplating step: electroplate the plating part, the electroplating solution comprising the following components: cuprous sulfate 20 g / L to 30 g / L, cuprous chloride 10 g / L to 20 g / L, dithiooxamide 20 g / L to 40 g / L, hydroxyethylidene diphosphonic acid 10 g / L to 20 g / L, ethylenediamine 2 g / L to 10 g / L, sodium tartrate 4 g / L to 12 g / L, sodium methylsulfonate 5 g / L to 10 g / L, polyethylene glycol 30 mg / L to 60 mg / L, polyvinyl alcohol 0.5 g / L to 1 g / L, and polyethylene oxide 0.2 g / L to 0.5 g / L; A plating part air-drying step: blow-dry the electroplated plating part.

2. The process according to claim 1, characterized in that, In the plating part surface micro-etching step, the micro-etching solution comprises: hydrogen peroxide 40 mg / L to 60 mg / L, sulfuric acid 30 mg / L to 90 mg / L, sodium persulfate 20 mg / L to 30 mg / L, sodium chloride 100 mg / L to 200 mg / L, tartaric acid 3 g / L to 6 g / L, diethylene glycol methyl ether 2 g / L to 4 g / L, and dibenzotriazole 4 g / L to 8 g / L.

3. The process of claim 2, wherein, In the plating part surface micro-etching step, the immersion time is 1 minute to 2 minutes, and the temperature of the micro-etching solution is 35 degrees Celsius to 45 degrees Celsius.

4. The process of claim 1, wherein, In the plating part pre-plating step, the pre-plating solution comprises the following components by mass: anhydrous copper sulfate 2 g / L to 4 g / L, copper chloride 2 g / L to 5 g / L, copper nitrate 3 g / L to 6 g / L, methanol 4 g / L to 8 g / L, sodium dodecyl benzene sulfonate 1 g / L to 2 g / L, triethanolamine 1 g / L to 2 g / L, sodium hypophosphite 12 g / L to 40 g / L, and citric acid 4 g / L to 8 g / L.

5. The process of claim 4, wherein, The temperature of the pre-plating solution is 45 degrees Celsius to 55 degrees Celsius, and the immersion time is 2 minutes to 5 minutes.

6. The process of claim 1, wherein, In the plating part electroplating step, the electroplating solution further comprises a stabilizer 30 mg / L to 50 mg / L, and the stabilizer is 6-maleic acid nitroquinolizine salt.

7. The process of claim 1, wherein, In the plating part electroplating step, the electroplating solution further comprises a brightener 8 g / L to 20 g / L, and the brightener is a mixture of antimony sulfate and antimony nitrate.

8. The process of claim 7, wherein, In the plating part electroplating step, the electroplating solution further comprises a surfactant 20 mg / L to 30 mg / L, and the surfactant is allyloxy polyoxyethylene ether.

9. The process of claim 1, wherein, In the plating step, the cathode current density is 25 A / dm 2 to 35 A / dm 2 .

10. The process of claim 1, wherein, In the plating part electroplating step, the temperature of the electroplating solution is 50 degrees Celsius to 80 degrees Celsius.

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