CN111394718B

CN111394718B - Passivation solution and copper surface film forming treatment method

Info

Publication number: CN111394718B
Application number: CN202010144118.7A
Authority: CN
Inventors: 熊猛; 易金彪; 况金权
Original assignee: Guangdong Dongming New Material Technology Co ltd
Current assignee: Guangdong Dongming New Material Technology Co ltd
Priority date: 2020-03-04
Filing date: 2020-03-04
Publication date: 2022-11-11
Anticipated expiration: 2040-03-04
Also published as: CN111394718A

Abstract

The invention relates to the technical field of copper surface treatment, and discloses a passivation solution and a copper surface film forming treatment method. The passivation solution comprises the following components in parts by weight: 0.5 to 2 portions of fluotantalate, 1 to 5 portions of metavanadate, 0.5 to 2 portions of corrosion inhibitor and 0.5 to 5 portions of surfactant. The copper surface film forming treatment method comprises the steps of degreasing treatment, polishing treatment, film removing treatment, passivation treatment, drying treatment and the like. The method has the advantages of simple operation, high film forming speed and good passivation effect, and can ensure that the passivated copper workpiece has excellent corrosion resistance.

Description

Passivation solution and copper surface film forming treatment method

Technical Field

The invention relates to the technical field of copper surface treatment, in particular to a passivation solution and a copper surface film forming treatment method.

Background

Copper is an alloy mainly composed of copper elements, has strong wear resistance and plasticity, is one of common basic metal materials in industrial production, and is widely used for small hardware such as joints, valves, heat exchangers, condensers, pipelines, submarine transportation pipes, electric appliance circuit gaskets, mechanical gears, locks and the like. Pure copper is soft metal, has red orange color band metallic luster when the surface is just cut, and has a purplish red simple substance. The ductility is good, and the thermal conductivity and the electric conductivity are high, so the material is the most commonly used material in cables and electric and electronic components, can also be used as a building material, and can form a plurality of alloys. Copper alloys have excellent mechanical properties and very low electrical resistivity, the most important of which are bronze and brass. In addition, copper is also a durable metal that can be recycled many times without compromising its mechanical properties. The surface of the copper has beautiful metallic luster after being machined, but if the surface of the copper is not passivated, the surface of the copper is easily oxidized to lose luster, the copper is further corroded in a humid environment, a matrix is damaged, and the phenomena of rust, verdigris and the like occur. In order to prevent discoloration and rust, the surface of copper is generally passivated with chromic acid or plated. However, chromic acid with high toxicity is used for the chromic acid passivation treatment, which is not environment-friendly; the electroplating process is relatively costly. In order to overcome the problems, the research on the passivation treatment of copper by replacing chromic acid with environment-friendly passivation solution has great significance.

For example, chinese patent CN103085380a discloses a method for passivating copper superhydrophobicity, and the adopted chemical deposition solution comprises the following components in concentration: 0.1mol/L copper sulfate, 0.005mol/L nickel sulfate, 1mol/L sodium acetate, 1mol/L boric acid, 1mol/L sodium hypophosphite and 35ppm polyethylene glycol. The passivation method is to place the copper workpiece in the chemical deposition solution for passivation treatment. Although the passivation method is simple to operate and environment-friendly, the passivation method has general corrosion resistance in acid, alkali and salt media and cannot be used for a long time in extreme severe environments such as oceans and the like; in addition, in the actual production, the film forming speed is too slow, the limitation is large, and the method cannot be applied to industrial large-scale production.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides the passivating solution with simple operation and higher film forming speed and the copper surface film forming treatment method, so that a passivated copper workpiece has excellent corrosion resistance.

The purpose of the invention is realized by the following technical scheme:

the passivation solution comprises the following components in parts by weight:

0.5 to 2 portions of fluotantalate, 1 to 5 portions of metavanadate, 0.5 to 2 portions of corrosion inhibitor and 0.5 to 5 portions of surfactant.

In one embodiment, the fluorotantalate comprises at least one of potassium fluorotantalate and sodium fluorotantalate.

In one embodiment, the metavanadate comprises at least one of sodium metavanadate, potassium metavanadate, and ammonium metavanadate.

In one embodiment, the corrosion inhibitor is 2-mercaptobenzothiazole.

In one embodiment, the surfactant is an alkyl glycoside.

In one embodiment, the pH of the passivating solution is from 7 to 8.

A copper surface film forming treatment method comprises the following steps:

and putting a copper workpiece into the passivation solution of any one of the embodiments, and performing passivation treatment to form a passivation film on the surface of the copper workpiece.

In one embodiment, before the operation of placing the copper workpiece into the passivation solution, the method further comprises the following steps:

putting the copper workpiece into degreasing and deoiling liquid at the temperature of 60-70 ℃, and carrying out degreasing treatment for 5-15 min; the degreasing deoiling liquid comprises the following components in parts by weight: 20 to 25 portions of sodium hydroxide, 20 to 25 portions of sodium carbonate, 8 to 20 portions of sodium tripolyphosphate and 0.5 to 2 portions of TX-10 active agent;

putting the copper workpiece into polishing solution at the temperature of 20-30 ℃ and carrying out polishing treatment for 1-3 min; the polishing solution comprises the following components in parts by weight: 15 to 25 portions of sulfuric acid, 200 to 300 portions of hydrogen peroxide, 3 to 10 portions of thiourea and 0.1 to 1 portion of activator;

placing the copper workpiece into a film removing solution at the temperature of 20-30 ℃ for film removing treatment for 15-25 s; the membrane removing liquid comprises the following components in parts by weight: 30 to 70 portions of sulfuric acid and 1 to 5 portions of wetting agent.

In one embodiment, after the passivation treatment operation, the copper workpiece is further subjected to a drying treatment at a temperature of 60-80 ℃ for 10-15 min.

Compared with the prior art, the invention has at least the following advantages:

the invention is chromium-free, low-toxicity and environment-friendly, uses the main film-forming salts of fluotantalate and metavanadate to passivate the surface of the copper workpiece, so as to generate a layer of compact passivation film containing vanadium oxide and tantalum oxide on the surface of the copper workpiece, and compared with single film-forming salts, the vanadium oxide and the tantalum oxide can mutually fill the gaps between the vanadium oxide and the tantalum oxide and the surface of the copper workpiece, so that the passivation film has higher compactness. Particularly, tantalum oxide has very excellent chemical properties and extremely high corrosion resistance, and does not react to hydrochloric acid, concentrated nitric acid and aqua regia under both cold and hot conditions. The fluorine element can promote the reaction of the tantalum element and the copper workpiece, accelerate the formation of a passivation film and improve the bonding strength of the passivation film and the copper workpiece. And the compactness and uniformity of the passive film can be improved by the corrosion inhibition effect of the corrosion inhibitor and the dispersion effect of the surfactant. Therefore, by proper proportion of the fluorotantalate, the metavanadate, the corrosion inhibitor and the surfactant, the formation of the passivation film can be accelerated, the compactness and the uniformity of the passivation film can be improved, the bonding strength of the passivation film and the copper workpiece can be improved, so that the passivated copper workpiece has extremely high corrosion resistance and does not react to hydrochloric acid, concentrated nitric acid and aqua regia under cold and hot conditions.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a flowchart illustrating a method for forming a film on a copper surface according to one embodiment of the present invention.

FIG. 2 is an external view of a copper workpiece after a 24-hour salt spray test in example 1.

FIG. 3 is an appearance diagram of a copper workpiece after 24h salt spray test after the film forming treatment in example 2 of the present invention.

FIG. 4 is an appearance diagram of a copper workpiece after 24h salt spray test after the film forming treatment in example 3 of the present invention.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully hereinafter with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In one embodiment, referring to fig. 1, a method for forming a film on a copper surface includes the following steps:

s110, putting the copper workpiece into degreasing and deoiling liquid for degreasing.

Generally, in the process of die-casting a copper workpiece, in order to make the formed copper workpiece easily separate from a die, a certain oily mold release agent is usually used to facilitate the separation of the copper workpiece from the die, so that the oily mold release agent can be adhered to the surface of the copper workpiece and is difficult to wash away by clear water, and oil stains adhered to the surface of the copper workpiece greatly affect subsequent processes, which easily affects the treatment effect of the subsequent processes. Therefore, it is necessary to remove the oily release agent by degreasing treatment to remove oil stains on the surface of the copper workpiece.

In order to better remove oil stains on the surface of a copper workpiece, in particular to remove stubborn oil stains on the surface of the copper workpiece, in one embodiment, the degreasing deoiling liquid comprises the following components in parts by weight: 20 to 25 portions of sodium hydroxide, 20 to 25 portions of sodium carbonate, 8 to 20 portions of sodium tripolyphosphate and 0.5 to 2 portions of TX-10 active agent. If the grease is not removed completely, the grease can prevent the chemical reaction between the zinc alloy workpiece and the passivating agent, so that the passivating film is light and dull in color, and even no passivating film exists in severe cases. The degreasing and degreasing fluid is similar and compatible with stubborn oil stains through sodium hydroxide, sodium carbonate and sodium tripolyphosphate, and is combined with a strong TX-10 active agent to emulsify the stubborn oil stains so as to achieve the purpose of efficiently removing the stubborn oil stains. For another example, the degreasing deoiling liquid comprises the following components in concentration: 20 g/L-25 g/L of sodium hydroxide, 20 g/L-25 g/L of sodium carbonate, 8 g/L-20 g/L of sodium tripolyphosphate and 0.5 g/L-2 g/L of TX-10 active agent. So can get rid of the stubborn greasy dirt on copper workpiece surface betterly, and can avoid the degrease to remove the problem that fluid and copper workpiece reaction attached to copper workpiece surface and influence the passivation treatment effect.

In order to better remove stubborn oil stains on the surface of the copper workpiece, in one embodiment, the copper workpiece is put into degreasing and degreasing liquid for ultrasonic degreasing treatment. So through the extremely strong degrease deoiling fluid of above-mentioned greasy dirt ability, combine ultrasonic vibration cleaning ability, can further get rid of the stubborn greasy dirt on copper workpiece surface. For another example, the temperature of the degreasing treatment is 60 ℃ to 70 ℃. More preferably, the temperature of the degreasing treatment is 65 ℃. For another example, the time of the degreasing treatment is 5min to 15min. More preferably, the time of the degreasing treatment is 10min, so that stubborn oil stains on the surface of the copper workpiece are better removed.

In one embodiment, after the degreasing operation and before the subsequent processes, i.e., before step S120, a water washing operation is further performed on the copper workpiece. For example, the copper workpiece is subjected to a water washing operation with deionized water, and as another example, the water washing operation is a counter-current water washing operation. In another example, the counter-current water washing operation is carried out using air agitation. For another example, the countercurrent washing operation is carried out for 2-3 times at normal temperature, so that degreasing and deoiling liquid on the surface of the copper workpiece can be cleaned, the influence of the degreasing and deoiling liquid on the subsequent process is reduced, and the passivation effect of the copper workpiece is improved.

And S120, putting the copper workpiece into polishing liquid for polishing treatment.

It should be noted that the surface of the copper workpiece is smooth, so that the bonding force between the passivation film generated by the subsequent passivation treatment and the copper workpiece is low, and the corrosion resistance is poor, so that the copper workpiece needs to be polished to increase the roughness of the surface of the copper workpiece and increase the bonding area between the passivation film and the copper workpiece, thereby improving the bonding strength between the copper workpiece and the passivation film, and further improving the corrosion resistance of the passivated copper workpiece.

In order to better improve the polishing treatment effect, in one embodiment, the polishing solution comprises the following components in parts by weight: 15 to 25 portions of sulfuric acid, 200 to 300 portions of hydrogen peroxide, 3 to 10 portions of thiourea and 0.1 to 1 portion of activator. Therefore, through the strong corrosion action of the sulfuric acid and the hydrogen peroxide, the corrosion inhibition action of the thiourea and the dispersion action of the active agent, micron-sized gullies can be formed on the surface of the copper workpiece more uniformly, the roughness of the surface of the copper workpiece can be increased through the micron-sized gullies, the combination area of the passivation film and the copper workpiece can be increased, the combination strength of the copper workpiece and the passivation film is improved, and the corrosion resistance of the passivated copper workpiece is further improved. As another example, the polishing solution includes the following components in the following concentrations: 15 g/L-25 g/L sulfuric acid, 200 g/L-300 g/L hydrogen peroxide, 3 g/L-10 g/L thiourea and 0.1 g/L-1 g/L active agent. This can improve the effect of the polishing treatment even more. In another example, the active agent is at least one of sodium dodecylbenzene sulfonate, a polyoxyethylene type active agent, an OP active agent, a TX-10 active agent, and an AEO-9 active agent. This can improve the effect of the polishing treatment even more.

In order to further improve the polishing effect, in one embodiment, the temperature of the polishing process is 20 ℃ to 30 ℃. More preferably, the temperature of the polishing process is 25 ℃. This can further improve the effect of the polishing treatment. For another example, the polishing time is 1min to 3min. More preferably, the time of the polishing process is 2min. This can further improve the effect of the polishing treatment. For another example, the copper workpiece is put into the polishing solution to be polished. Therefore, by using the polishing solution with excellent polishing effect, and combining the mechanical effect (namely dispersion effect), the cavitation effect and the thermal effect of the ultrasonic wave, the polishing effect of the polishing solution can be enhanced, the uniformity of the distribution of the micron gullies can be increased, the depth of the micron gullies can be increased, and the complexity of the structure of the micron gullies can be increased, so that the bonding strength of the copper workpiece and the passivation film can be improved, and the corrosion resistance of the passivated copper workpiece can be further improved.

In one embodiment, a water washing operation is also performed on the copper workpiece after the polishing process and before the subsequent process, i.e., step S130. For example, the copper workpiece is subjected to a water washing operation with deionized water, and as another example, the water washing operation is a counter-current water washing operation. In another example, the counter-current water washing operation is carried out using air agitation. For another example, at normal temperature, countercurrent washing operation is performed for 2-3 times, so that the polishing solution on the surface of the copper workpiece can be washed away, the influence of the polishing solution on the subsequent process is reduced, and the passivation effect of the copper workpiece is improved.

S130, placing the copper workpiece into a film removing liquid for film removing treatment.

It can be understood that a sparse oxide film may be formed on the copper workpiece due to air oxidation, which affects the low binding force between the passivation film generated by the subsequent passivation treatment and the copper workpiece and the poor corrosion resistance, so that the copper workpiece needs to be subjected to film removal treatment to improve the binding strength between the copper workpiece and the passivation film, and further improve the corrosion resistance of the passivated copper workpiece.

In order to better improve the effect of the stripping treatment, in one embodiment, the stripping solution comprises the following components in parts by weight: 30 to 70 portions of sulfuric acid and 1 to 5 portions of wetting agent. Therefore, through the strong corrosion action of the sulfuric acid, the dispersion action of the wetting agent is combined, the surface tension or the interfacial tension of the sulfuric acid is reduced, so that the sulfuric acid can be spread on the surface of the copper workpiece and can permeate into the surface of the copper workpiece, an oxidation film on the surface of the copper workpiece is uniformly removed, the activation effect is achieved on the surface of the copper workpiece, the reaction of the copper workpiece and the passivation solution is facilitated, meanwhile, the roughness of the surface of the copper workpiece can be further increased, the depth of a micron gully is further increased, the complexity of the structure of the micron gully is further increased, the bonding strength of the copper workpiece and the passivation film is further improved, and the corrosion resistance of the passivated copper workpiece is further improved. For another example, the stripping solution comprises the following components in concentration: 30-70 g/L of sulfuric acid and 1-5 g/L of wetting agent. Thus, the effect of the film removing treatment can be better improved. As another example, the wetting agent is at least one of sodium dodecylbenzene sulfonate, a polyoxyethylene-type active agent, an OP active agent, a TX-10 active agent, and an AEO-9 active agent. Thus, the effect of the film removing treatment can be better improved.

In order to further improve the effect of the polishing treatment, in one embodiment, the temperature of the polishing treatment is 20 ℃ to 30 ℃, so that the effect of the polishing treatment can be further improved. More preferably, the temperature of the polishing process is 25 ℃, so that the effect of the polishing process can be further improved. In another example, the polishing time is 15s to 25s, which can further improve the polishing effect. More preferably, the time of the polishing process is 20s, so that the effect of the polishing process can be further improved. In another example, the copper workpiece is put into a stripping solution for stripping treatment. Therefore, by using the film removing liquid with excellent film removing effect and combining the mechanical effect (namely dispersion effect), the cavitation effect and the thermal effect of ultrasonic waves, the film removing effect of the film removing liquid can be further enhanced, the uniformity of the distribution of the micron gullies can be further increased, the depth of the micron gullies can be further increased, and the complexity of the structure of the micron gullies can be further increased, so that the bonding strength between the copper workpiece and the passivation film can be further improved, and the corrosion resistance of the passivated copper workpiece can be further improved.

In one embodiment, a water washing operation is also performed on the copper workpiece after the film removing operation and before the subsequent processes, i.e., step S140. For example, the copper workpiece is subjected to a water washing operation with deionized water, and as another example, the water washing operation is a counter-current water washing operation. In another example, the counter-current water washing operation is carried out using air agitation. For another example, at normal temperature, countercurrent washing is performed for 2-3 times, so that the membrane removing liquid on the surface of the copper workpiece can be washed away, the influence of the membrane removing liquid on the subsequent process is reduced, and the passivation effect of the copper workpiece is improved.

S140, putting the copper workpiece into passivation solution for passivation treatment to form a passivation film on the surface of the copper workpiece.

The corrosion resistance of the passivated copper workpiece is improved by generating a layer of compact passivation film on the surface of the copper workpiece through passivation treatment.

The corrosion resistance of the passivation film is closely related to the components and the component proportion of the passivation solution, and in order to improve the corrosion resistance of the passivation film, in one embodiment, the passivation solution comprises the following components in parts by weight: 0.5 to 2 portions of fluotantalate, 1 to 5 portions of metavanadate, 0.5 to 2 portions of corrosion inhibitor and 0.5 to 5 portions of surfactant. Thus, the surface of the copper workpiece is passivated by using the main film-forming salts of the fluorotantalate and the metavanadate, so that a layer of compact passivation film containing vanadium oxide and tantalum oxide is generated on the surface of the copper workpiece. Particularly, tantalum oxide has very excellent chemical properties, has extremely high corrosion resistance, and is unreactive to hydrochloric acid, concentrated nitric acid, and "aqua regia" both under cold and hot conditions. The fluorine element can promote the reaction of the tantalum element and the copper workpiece, accelerate the formation of a passivation film and improve the bonding strength of the passivation film and the copper workpiece. And the corrosion inhibition effect of the corrosion inhibitor and the dispersion effect of the surfactant are added, so that the compactness and uniformity of the passive film can be improved. Therefore, by proper proportion of the fluotantalate, the metavanadate, the corrosion inhibitor and the surfactant, the formation of the passivation film can be accelerated, the compactness and the uniformity of the passivation film can be improved, the bonding strength of the passivation film and the copper workpiece can be improved, so that the passivated copper workpiece has extremely high corrosion resistance and does not react with hydrochloric acid, concentrated nitric acid and aqua regia under cold and hot conditions.

In order to accelerate the formation of the passivation film, improve the compactness and uniformity of the passivation film and improve the bonding strength of the passivation film and the copper workpiece, so that the passivated copper workpiece has extremely high corrosion resistance, in one embodiment, the passivation solution comprises the following components in concentration: 0.5-2 g/L of fluotantalate, 1-5 g/L of metavanadate, 0.5-2 g/L of corrosion inhibitor and 0.5-5 g/L of surfactant. Therefore, the formation of the passivation film can be accelerated, the compactness and the uniformity of the passivation film can be improved, and the bonding strength between the passivation film and the copper workpiece can be improved, so that the passivated copper workpiece has extremely high corrosion resistance.

In order to further accelerate the formation of the passivation film, further improve the compactness and uniformity of the passivation film, and further improve the bonding strength between the passivation film and the copper workpiece, so that the passivated copper workpiece has extremely high corrosion resistance, in one embodiment, the passivation solution comprises the following components in concentration: 1.2g/L of fluotantalate, 3g/L of metavanadate, 1.2g/L of corrosion inhibitor and 2.2g/L of surfactant. Therefore, the formation of the passive film can be accelerated, the compactness and uniformity of the passive film can be improved, and the bonding strength of the passive film and a copper workpiece can be improved, so that the passivated copper workpiece has extremely high corrosion resistance. Therefore, the formation of the passivation film can be further accelerated, the compactness and uniformity of the passivation film can be further improved, and the bonding strength between the passivation film and the copper workpiece can be further improved, so that the passivated copper workpiece has extremely high corrosion resistance. As another example, the fluorotantalate includes at least one of potassium fluorotantalate and sodium fluorotantalate. As another example, the metavanadate includes at least one of sodium metavanadate, potassium metavanadate, and ammonium metavanadate. As another example, the corrosion inhibitor is 2-mercaptobenzothiazole. As another example, the surfactant is an alkyl glycoside. Therefore, the formation of the passive film can be further accelerated, the compactness and uniformity of the passive film can be further improved, and the bonding strength of the passive film and a copper workpiece can be further improved, so that the passivated copper workpiece has extremely high corrosion resistance.

In order to further improve the passivation effect of the copper workpiece, in one embodiment, the pH value of the passivation solution is 7-8, and the pH value of the passivation solution is close to neutral, so that the using condition of the passivation solution is very mild. More preferably, the pH of the passivation solution is 7.5. This enables further passivation of the copper workpiece. For another example, the temperature of the passivation treatment is 40 ℃ to 50 ℃, the temperature of the passivation treatment does not need high temperature, and the operation condition is very mild. More preferably, the temperature of the passivation treatment is 45 ℃. This enables further passivation of the copper workpiece. For another example, the time of the passivation treatment is 2min to 5min, so that a good passivation effect can be achieved in a short time. More preferably, the time of the passivation treatment is 3min. This enables further passivation of the copper workpiece.

In one embodiment, after the passivation process is performed and before the subsequent process, i.e., before step S150, a water washing operation is also performed on the copper workpiece. For example, the copper workpiece is subjected to a water washing operation with deionized water, and as another example, the water washing operation is a counter-current water washing operation. In another example, the counter-current water washing operation is carried out using air agitation. For another example, at normal temperature, countercurrent washing operation is carried out for 2-3 times, so that the passivation solution on the surface of the copper workpiece can be washed away, the influence of the passivation solution on the subsequent process is reduced, and the bonding strength of the passivation film and the copper workpiece is improved.

S150, drying the copper workpiece.

It is understood that the wet passivation film after the passivation process is not completely stable, and if the temperature is too high, the passivation film is damaged; if the temperature is low, the drying effect is not good. In order to achieve a better drying effect, in one embodiment, the temperature of the drying treatment is 60 ℃ to 80 ℃, so that a better drying effect can be achieved. More preferably, the temperature of the drying treatment is 70 ℃, so that better drying effect can be achieved. For another example, the drying time is 10min to 15min. So can reach better drying effect. More preferably, the drying time is 12min to 13min. So can reach better drying effect.

In order to solve the problem that the corrosion resistance of the passivation film is generally deteriorated due to the fact that the corrosion material diffuses gradually from the inside of the passivation film as corrosion points, which is often only a few micrometers, the corrosion resistance of the passivation film is not determined by the entire passivation film, but the fine poor bonding portions are often determined by the presence of the passivation film, and the corrosion resistance of the passivation film is generally deteriorated, the fine poor bonding portions need to be repaired, and in order to further improve the corrosion resistance of the passivated copper workpiece, in one embodiment, after the drying operation, the copper workpiece is subjected to salt spray treatment at a temperature of 150 to 200 ℃ for 24 to 48 hours, then the copper workpiece is placed in water, and then ultrasonic cleaning treatment is performed, and then the copper workpiece is placed in the passivation solution to perform the passivation treatment. It should be noted that if the passivation film has a fine and poor bonding portion, the passivation film will be separated from the surface of the copper workpiece after the high-temperature salt spray treatment and the ultrasonic cleaning treatment, so that the fine portion of the surface of the copper workpiece is exposed, and then the passivation film with stronger bonding force and higher compactness is regenerated at the exposed fine portion, thereby further improving the corrosion resistance of the passivated copper workpiece.

the invention is chromium-free, low-toxicity and environment-friendly, uses the main film-forming salts of fluotantalate and metavanadate to passivate the surface of the copper workpiece, so as to generate a layer of compact passivation film containing vanadium oxide and tantalum oxide on the surface of the copper workpiece, and compared with single film-forming salts, the vanadium oxide and the tantalum oxide can mutually fill the gaps between the vanadium oxide and the tantalum oxide and the surface of the copper workpiece, so that the passivation film has higher compactness. Particularly, tantalum oxide has very excellent chemical properties and extremely high corrosion resistance, and does not react to hydrochloric acid, concentrated nitric acid and aqua regia under both cold and hot conditions. The fluorine element can promote the reaction of the tantalum element and the copper workpiece, accelerate the formation of a passivation film and improve the bonding strength of the passivation film and the copper workpiece. And the corrosion inhibition effect of the corrosion inhibitor and the dispersion effect of the surfactant are added, so that the compactness and uniformity of the passive film can be improved. Therefore, by proper proportion of the fluorotantalate, the metavanadate, the corrosion inhibitor and the surfactant, the formation of the passivation film can be accelerated, the compactness and the uniformity of the passivation film can be improved, the bonding strength of the passivation film and the copper workpiece can be improved, so that the passivated copper workpiece has extremely high corrosion resistance and does not react to hydrochloric acid, concentrated nitric acid and aqua regia under cold and hot conditions.

The following are detailed description of the embodiments

Example 1

S111, putting the copper workpiece into degreasing and deoiling liquid at the temperature of 60 ℃, performing degreasing treatment for 15min, and then performing water washing operation on the copper workpiece; the degreasing deoiling liquid comprises the following components in concentration: 25g/L of sodium hydroxide, 25g/L of sodium carbonate, 8g/L of sodium tripolyphosphate and 1g/L of TX-10 active agent.

S121, putting the copper workpiece into polishing solution at the temperature of 20 ℃, polishing for 3min, and then washing the copper workpiece; the polishing solution comprises the following components in concentration: 25g/L of sulfuric acid, 300g/L of hydrogen peroxide, 4g/L of thiourea and 0.5g/L of sodium dodecyl benzene sulfonate.

S131, putting the copper workpiece into a film removing liquid at the temperature of 20 ℃, performing film removing treatment for 25S, and then performing water washing operation on the copper workpiece; the membrane removing liquid comprises the following components in concentration: 30g/L of sulfuric acid and 2g/L of AEO-9 active agent.

S141, putting the copper workpiece into passivation solution at the temperature of 45 ℃, performing passivation treatment for 3min to form a passivation film on the surface of the copper workpiece, and then performing water washing operation on the copper workpiece; wherein the passivation solution comprises the following components in concentration: 1g/L of potassium fluotantalate, 2g/L of sodium metavanadate, 0.5g/L of 2-mercaptobenzothiazole and 0.5g/L of alkyl glycoside.

S151, drying the copper workpiece for 15min at the temperature of 60 ℃.

Example 2

S112, putting the copper workpiece into degreasing and deoiling liquid at the temperature of 70 ℃, and performing degreasing treatment for 5min; the degreasing deoiling liquid comprises the following components in concentration: 20g/L of sodium hydroxide, 20g/L of sodium carbonate, 16g/L of sodium tripolyphosphate and 2g/L of TX-10 active agent.

S122, putting the copper workpiece into polishing liquid at the temperature of 30 ℃, and performing polishing treatment for 1min; the polishing solution comprises the following components in concentration: 15g/L of sulfuric acid, 200g/L of hydrogen peroxide, 3g/L of thiourea and 1g/L of AEO-9 active agent.

S132, placing the copper workpiece into a film removing liquid at the temperature of 30 ℃ to carry out film removing treatment for 15S; the membrane removing liquid comprises the following components in concentration: 70g/L of sulfuric acid and 5g/L of polyoxyethylene type active agent.

S142, putting the copper workpiece into a passivation solution at the temperature of 40 ℃, and carrying out passivation treatment for 5min to form a passivation film on the surface of the copper workpiece; wherein the passivation solution comprises the following components in concentration: 2g/L of sodium fluorotantalate, 5g/L of potassium metavanadate, 1g/L of 2-mercaptobenzothiazole and 1g/L of alkyl glycoside.

S152, drying the copper workpiece for 10min at the temperature of 80 ℃.

Example 3

S113, putting the copper workpiece into degreasing and deoiling liquid at the temperature of 65 ℃, and performing degreasing treatment for 5-15 min; the degreasing deoiling liquid comprises the following components in concentration: 23g/L of sodium hydroxide, 22g/L of sodium carbonate, 20g/L of sodium tripolyphosphate and 0.5g/L of TX-10 active agent.

S123, putting the copper workpiece into polishing liquid at normal temperature, and performing polishing treatment for 2min; the polishing solution comprises the following components in concentration: 20g/L of sulfuric acid, 250g/L of hydrogen peroxide, 10g/L of thiourea and 0.1g/L of sodium dodecyl benzene sulfonate.

S133, placing the copper workpiece into a film removing liquid at normal temperature, and performing film removing treatment for 20S; the membrane removing liquid comprises the following components in concentration: 50g/L of sulfuric acid and 1g/L of sodium dodecyl benzene sulfonate.

S143, putting the copper workpiece into passivation solution at the temperature of 50 ℃, and carrying out passivation treatment for 2min to form a passivation film on the surface of the copper workpiece; wherein the pH value of the passivation solution is 7-8, and the passivation solution comprises the following components in concentration: 0.5g/L of sodium fluotantalate, 1g/L of potassium metavanadate, 2g/L of 2-mercaptobenzothiazole and 3g/L of alkyl glycoside.

S153, drying the copper workpiece for 13min at the temperature of 70 ℃.

Example 4

S114, putting the copper workpiece into degreasing deoiling liquid at the temperature of 65 ℃, and performing degreasing treatment for 10min; the degreasing deoiling liquid comprises the following components in concentration: 22g/L of sodium hydroxide, 23g/L of sodium carbonate, 14g/L of sodium tripolyphosphate and 1.2g/L of TX-10 active agent.

S124, putting the copper workpiece into polishing solution at normal temperature, and performing polishing treatment for 2min; the polishing solution comprises the following components in concentration: 20g/L of sulfuric acid, 250g/L of hydrogen peroxide, 6.5g/L of thiourea and 0.6g/L of AEO-9 active agent.

S134, placing the copper workpiece into a film removing liquid at normal temperature, and performing film removing treatment for 20S; the film removing liquid comprises the following components in concentration: 50g/L of sulfuric acid and 3g/L of AEO-9 active agent.

S144, putting the copper workpiece into passivation solution at the temperature of 45 ℃, and carrying out passivation treatment for 3min to form a passivation film on the surface of the copper workpiece; wherein the passivation solution comprises the following components in concentration: 1.2g/L of potassium fluotantalate, 3g/L of ammonium metavanadate, 1.2g/L of 2-mercaptobenzothiazole and 2.2g/L of alkyl glycoside.

S154, drying the copper workpiece at the temperature of 70 ℃ for 12min.

Example 5

The passivation solutions used in examples 1 to 4 were the passivation solutions just prepared, while the passivation solution used in example 5 was the passivation solution stored for 360 days, and the rest was the same as in example 4.

Comparative example 1

S116, putting the copper workpiece into degreasing deoiling liquid at the temperature of 65 ℃, and performing degreasing treatment for 10min; the degreasing deoiling liquid comprises the following components in concentration: 22g/L of sodium hydroxide, 23g/L of sodium carbonate, 14g/L of sodium tripolyphosphate and 1.2g/L of TX-10 active agent.

S126, putting the copper workpiece into polishing liquid at normal temperature, and performing polishing treatment for 2min; the polishing solution comprises the following components in concentration: 20g/L of sulfuric acid, 250g/L of hydrogen peroxide, 6.5g/L of thiourea and 0.6g/L of AEO-9 active agent.

S136, placing the copper workpiece into a film removing liquid at normal temperature, and performing film removing treatment for 20S; the film removing liquid comprises the following components in concentration: 50g/L of sulfuric acid and 3g/L of AEO-9 active agent.

S146, putting the copper workpiece into passivation solution at the temperature of 45 ℃, and carrying out passivation treatment for 3min to form a passivation film on the surface of the copper workpiece; wherein the passivation solution comprises the following components in concentration: 1.2g/L of potassium fluozirconate, 3g/L of ammonium metavanadate, 1.2g/L of thiourea and 2.2g/L of TX-10 active agent.

And S156, drying the copper workpiece for 12min at the temperature of 70 ℃.

And (3) performance testing: 1. the copper workpieces subjected to film formation treatment in examples 1 to 5 and comparative example 1 were placed on an M-2000 ring block type frictional wear tester, and the dynamic friction coefficients of the respective passive films were measured. 2. The copper workpieces after the film formation treatments of examples 1 to 5 and comparative example 1 were subjected to a hundred-grid test. 3. The copper workpieces subjected to film formation treatment in examples 1 to 5 and comparative example 1 were placed in 98% aqua regia solutions, and the surfaces were observed after 30 min. 4. The copper workpieces subjected to the film forming treatment in examples 1 to 5 and comparative example 1 were placed in 25% sodium hydroxide solutions, and the surfaces were observed after 30 min. 5. Salt spray tests were carried out on the copper workpieces subjected to the film forming treatments of examples 1 to 5 and comparative example 1 according to ASTM B-117, and the surfaces were observed after spraying for 24 hours, wherein the appearance of the copper workpiece subjected to the salt spray test for 24 hours after the film forming treatment of example 1 is shown in FIG. 2, the appearance of the copper workpiece subjected to the salt spray test for 24 hours after the film forming treatment of example 2 is shown in FIG. 3, and the appearance of the copper workpiece subjected to the salt spray test for 24 hours after the film forming treatment of example 3 is shown in FIG. 4. 6. The copper workpieces subjected to film formation treatment in examples 1 to 5 and comparative example 1 were subjected to a salt spray test in accordance with ASTM B-117, and the surfaces thereof were observed after continuous spraying for 168 hours. The results of the above performance tests are shown in Table 1.

TABLE 1

As can be seen from table 1, fig. 2 and fig. 3, the film forming method of the present invention is simple in operation, mild in action conditions, and fast in film forming speed. The passivation solution of the invention has no chromium, low toxicity and environmental protection, has good storage resistance, forms a passivation film on a copper workpiece after the film forming treatment of the passivation solution of the invention, has uniform and smooth passivation film, higher bonding strength with the copper workpiece, excellent glossiness, lubricity, alkali resistance, acid resistance and corrosion resistance,

the above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent should be subject to the appended claims.

Claims

1. The passivation solution is characterized by comprising the following components:

0.5 to 2g/L of fluotantalate, 1 to 5g/L of metavanadate, 0.5 to 2g/L of corrosion inhibitor and 0.5 to 5g/L of surfactant;

the corrosion inhibitor is 2-mercaptobenzothiazole;

the pH value of the passivation solution is 7~8;

the fluotantalate comprises at least one of potassium fluotantalate and sodium fluotantalate;

the surfactant is alkyl glycoside.

2. The passivation solution of claim 1, wherein the metavanadate comprises at least one of sodium metavanadate, potassium metavanadate, and ammonium metavanadate.

3. A method for forming a film on a copper surface, comprising the steps of:

putting a copper workpiece into the passivation solution of any one of claims 1~2, and performing passivation treatment to form a passivation film on the surface of the copper workpiece.

4. The method for film formation on the copper surface according to claim 3, wherein the temperature of the passivation treatment is 40 ℃ to 50 ℃, and the time of the passivation treatment is 2min to 5min.

5. The method according to claim 4, further comprising, before the step of placing the copper workpiece in the passivation solution:

putting the copper workpiece into degreasing deoiling liquid at the temperature of 60-70 ℃, and performing degreasing treatment for 5-15min; the degreasing deoiling liquid comprises the following components in parts by weight: 20 to 25 parts of sodium hydroxide, 20 to 25 parts of sodium carbonate, 8 to 20 parts of sodium tripolyphosphate and 0.5 to 2 parts of TX-10 active agent;

putting the copper workpiece into polishing liquid at the temperature of 20-30 ℃, and performing polishing treatment for 1-3 min; the polishing solution comprises the following components in parts by weight: 15 to 25 parts of sulfuric acid, 200 to 300 parts of hydrogen peroxide, 3 to 10 parts of thiourea and 0.1 to 1 part of an active agent;

putting the copper workpiece into a film removing liquid at the temperature of 20-30 ℃, and performing film removing treatment for 15s-25s; the membrane removing liquid comprises the following components in parts by weight: 30 to 70 parts of sulfuric acid and 4736 parts of a wetting agent 1~5.

6. The method for film formation on the copper surface according to claim 5, wherein after the passivation treatment, the copper workpiece is further dried at a temperature of 60 ℃ to 80 ℃ for 10min to 15min.