Iron-nickel alloy rapid and stable etching solution and working method thereof

Abstract

The invention belongs to the technical field of etching processing, and particularly relates to an iron-nickel alloy rapid and stable etching solution and a working method thereof, the etching solution comprises 30-40 wt% of ferric trichloride, hydrochloric acid with the concentration of 80-140 mL / L, nitric acid with the concentration of 20-60 mL / L, sodium hypochlorite with the concentration of 20-50 g / L, glacial acetic acid with the concentration of 10-40 mL / L and ultrapure deionized water. The etching temperature is about 40 DEG C; the etching time is 10 to 60 minutes. The etching speed is 20 [mu] m / min, and the maximum etching amount is 5g / L; according to the method, the concentration of ferric trichloride, the concentration of nitric acid, the concentration of hydrochloric acid, the concentration of sodium hypochlorite, the concentration of glacial acetic acid and the reaction temperature are optimized and adjusted, excessive etching or uneven etching can be avoided, accurate etching of a fine structure is ensured, and the method is particularly suitable for complex iron-nickel alloy patterns. Meanwhile, deposition or blockage caused by byproducts is reduced, the etching reaction speed is increased, the processing time is shortened, and therefore the etching efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of etching processing, and in particular relates to a fast and stable iron-nickel alloy etching solution and a working method thereof. Background Art

[0002] Etching is a technology that uses chemical reactions to remove specific parts of the material surface. It is widely used in metal processing, printed circuit board manufacturing, semiconductor manufacturing and other fields. Etching can accurately form complex patterns or structures on the material surface. The etching process usually includes the following steps: pre-treatment (cleaning, degreasing), coating of anti-corrosion layer, exposure and development, etching and post-processing.

[0003] Selecting the right etching solution is crucial to ensure etching quality and efficiency. Some traditional etching solutions may contain harmful substances, such as hexavalent chromium, which are now gradually being replaced by safer and more environmentally friendly alternatives. Different metals or alloys have different reactivity to etching solutions. Depending on production needs, sometimes fast etching is required to improve production efficiency, while sometimes it is desirable to control the etching speed to obtain finer patterns. The etching rate can be adjusted by adjusting the etching solution concentration, temperature, or adding inhibitors.

[0004] Due to its excellent physical properties and chemical stability, iron-nickel alloys are widely used in many high-tech fields, such as precision instruments, aerospace, electronic components, etc. Therefore, it is very important to perform precise etching on them. The selection of etching solution for iron-nickel alloys needs to take into account factors such as alloy composition, etching accuracy requirements, etching speed, and environmental impact. Ferric chloride (FeCl3) solution is suitable for rough etching or pretreatment of iron-nickel alloys. It is characterized by fast etching speed and is suitable for large-area etching. It is low in cost and easy to obtain. As etching proceeds, Fe 3+ When reacting with iron-nickel alloy, it is gradually reduced to Fe 2+ At the same time, the metal nickel is oxidized to generate Ni 2+ And enter the etching solution. 3+ The reduction in concentration and Ni 2+ With the increase of Ni content, the etching efficiency gradually decreases. 2+ The increase in concentration also tends to cause the etched surface to become rough.

[0005] The Chinese invention patent with publication number CN117328065A discloses a semiconductor iron-nickel alloy thinning etching solution, its preparation method and use, using inorganic acid and organic acid, with surfactant, better chelating Fe ions, preventing the formation of precipitation and being unable to clean. Oxalic acid and glacial acetic acid are selected to etch and chelate iron ions more gently, suppress the damage of dissolved iron ions to the metal surface, maintain a stable and controllable etching rate, and prevent the etching reaction from being violent and causing the substrate roughness to become larger. However, for some processing processes that require more refined etching quality of the iron-nickel alloy surface, such as precision instruments and chips, during the etching process, such etching solutions are prone to excessive etching, surface roughness increases, and even damages the workpiece. At the same time, the dosage of its specific reagents is relatively broad, and there is room for improvement in etching efficiency.

[0006] How to improve the composition of iron-nickel alloy etching solution, provide more suitable reaction conditions, further improve etching efficiency, and avoid affecting the environment has become an urgent problem to be solved. Summary of the invention

[0007] In view of the above-mentioned deficiencies in the prior art, the problem to be solved by the present invention is that the etching efficiency is not high in the existing iron-nickel alloy etching process, and for precision components, over-etching will occur, and the surface roughness will increase. The present invention provides a fast and stable iron-nickel alloy etching solution and a working method thereof, improves the formula and component ratio of the etching solution, adds corrosion inhibitors and oxidants, increases the etching speed, and achieves the effect of surface fine processing.

[0008] The present invention adopts the following technical scheme: a fast and stable iron-nickel alloy etching solution, comprising 30-40wt% of trivalent iron salt, 80-140mL / L of a first strong acid concentration, 20-60mL / L of a second strong acid concentration, 20-50g / L of an oxidant, 10-40mL / L of a corrosion inhibitor, and 15-30ml / L of a complexing agent.

[0009] The etching solution according to another embodiment of the present invention or any of the aforementioned embodiments further comprises ultrapure deionized water.

[0010] According to another embodiment of the present invention or the etching solution of any of the above embodiments, the trivalent iron salt is ferric chloride.

[0011] According to another embodiment of the present invention or the etching solution of any of the above embodiments, the first strong acid is hydrochloric acid, and the second strong acid is nitric acid.

[0012] According to another embodiment of the present invention or the etching solution of any of the aforementioned embodiments, the oxidant is sodium hypochlorite, the corrosion inhibitor is glacial acetic acid, and the complexing agent is ethylenediaminetetraacetic acid.

[0013] According to another embodiment of the present invention or the etching solution of any of the above embodiments, the concentration of sodium hypochlorite is 40 g / L, and the concentration of glacial acetic acid is 20 ml / L.

[0014] Correspondingly, a working method of a fast and stable etching solution for iron-nickel alloy is disclosed, wherein the etching temperature is about 40° C. and the etching time is 10-60 minutes.

[0015] According to a working method of etching liquid in another embodiment of the present invention or any of the above embodiments, during the etching process, the etching liquid should be stirred evenly to avoid uneven etching caused by different local chemical reaction rates.

[0016] According to another embodiment of the present invention or any of the aforementioned embodiments, the etching liquid working method, wherein, before etching, ensure that the surface of the iron-nickel alloy is clean and free of grease, oxides or other impurities to ensure the uniformity and consistency of the etching effect; after etching, the workpiece should be immediately removed from the etching liquid and thoroughly cleaned to remove residual chemicals to prevent continued reaction or surface contamination.

[0017] Beneficial effects of the present invention: The fast and stable iron-nickel alloy etching solution and the working method thereof disclosed by the present invention optimize and adjust the concentration of ferric chloride, nitric acid, hydrochloric acid, sodium hypochlorite, glacial acetic acid, and reaction temperature, thereby avoiding excessive etching or uneven etching, ensuring accurate etching of fine structures, and being particularly suitable for complex iron-nickel alloy patterns. At the same time, the deposition or blockage caused by by-products is reduced, the rate of etching reaction is accelerated, and the processing time is shortened, thereby improving etching efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the etching rate curve of the iron-nickel alloy at different temperatures according to the present invention; Figure 2 It is a curve schematic diagram of the effect of ferric chloride concentration on etching rate according to the present invention; Figure 3 It is a curve schematic diagram of the effect of nitric acid concentration on etching rate according to the present invention; Figure 4 It is a curve schematic diagram of the effect of hydrochloric acid concentration on etching rate according to the present invention; Figure 5 It is a curve schematic diagram of the effect of sodium hypochlorite concentration on etching rate according to the present invention; Figure 6 It is a curve schematic diagram of the effect of glacial acetic acid on etching rate according to the present invention; DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] The fast and stable etching solution of the present invention has a fast etching speed of 20 μm / min, high stability and a maximum etching amount of 5 g / L.

[0021] The present invention uses ultrapure deionized water to prepare etching solution. The content of ions, particles and microorganisms in ultrapure deionized water is extremely low, which can effectively prevent impurities from contaminating the etching solution and prevent impurities from reacting adversely with chemical components in the etching solution to affect the etching effect. Ultrapure deionized water does not contain any dissolved salts or organic matter, which can ensure that the components of the etching solution remain pure, reduce unnecessary chemical reactions, and thus improve the stability and life of the etching solution. Dissolved oxygen and other impurities in ordinary water may cause metal corrosion. The use of ultrapure deionized water can reduce these impurities, reduce the risk of corrosion, and extend the service life of equipment and materials.

[0022] The present invention provides a fast and stable etching solution for iron-nickel alloy, comprising 30-40 wt % of a ferric iron salt, 80-140 mL / L of a first strong acid concentration, 20-60 mL / L of a second strong acid concentration, 20-50 g / L of an oxidant, 10-40 mL / L of a corrosion inhibitor, and 15-30 ml / L of a complexing agent. Ultrapure deionized water is also included. The ferric iron salt is ferric chloride, the first strong acid is hydrochloric acid, and the second strong acid is nitric acid. The oxidant is sodium hypochlorite. Iron-nickel alloy etching usually requires an oxidant to promote the reaction, which can help accelerate the oxidation and dissolution of the metal, thereby accelerating the reaction.

[0023] The corrosion inhibitor is glacial acetic acid. The main function of adding the corrosion inhibitor to the etching solution is to slow down the corrosion rate during the etching process and protect the parts that do not need to be corroded, thereby making the etching more controllable.

[0024] The complexing agent is ethylenediaminetetraacetic acid, which can form a stable complex with metal ions to prevent the metal ions from being deposited back on the surface, thereby accelerating the etching process.

[0025] Preferably, the concentration of sodium hypochlorite is 40 g / L, and the concentration of glacial acetic acid is 20 ml / L.

[0026] Accordingly, a working method of a fast and stable etching solution for an iron-nickel alloy is disclosed, wherein the etching temperature is about 40°C; and the etching time is 10-60 minutes. During the etching process, the etching solution should be stirred evenly to avoid uneven etching caused by different local chemical reaction rates. Before etching, ensure that the surface of the iron-nickel alloy is clean and free of grease, oxides or other impurities to ensure the uniformity and consistency of the etching effect; after etching, the workpiece should be immediately removed from the etching solution and thoroughly cleaned to remove residual chemicals to prevent continued reaction or surface contamination.

[0027] Working principle of the present invention: The present invention adopts the following method and principle to increase the reaction speed of ferric chloride (FeCl3) etching solution: 1. Increase the concentration of etching solution: Adjusting the concentration of ferric chloride, hydrochloric acid, nitric acid, glacial acetic acid, and sodium hypochlorite in the ferric chloride solution can increase the content of active ingredients involved in the reaction during the etching process, thereby accelerating the reaction rate. However, too high a concentration may lead to uneven etching, and the concentration range needs to be carefully controlled.

[0028] 2. Raise the temperature: Raising the temperature of the etching solution will speed up the molecular movement, thereby increasing the reaction rate. Usually within the temperature range (such as 40°C to 50°C), the etching rate will be significantly accelerated, but care should be taken to avoid excessively high temperatures that may cause the evaporation of harmful substances.

[0029] 3. Stirring or flowing: By stirring the etching solution or using a flowing etching environment, the contact between the reactants and the material to be etched can be accelerated, and the reaction products can be removed to improve the reaction efficiency. Stirring can reduce local saturation and ensure uniform etching.

[0030] Adjusting pH: The reaction conditions of the etching solution can be optimized by properly adjusting its acidity and alkalinity (adding two acids), thereby accelerating the reaction rate.

[0031] Reducing oxide film: During the etching process, oxide film or other byproducts may be generated on the metal surface, which hinders further reaction. The present invention uses a complexing agent to reduce the formation of such film and improve etching efficiency.

[0032] The present invention obtains the best etching effect of ferric chloride etching solution on steel sheet at 40°C through the following research. Therefore, in the actual operation of the factory, the temperature should be controlled at about 40°C, and the etching solution formula used is 40wt% ferric chloride concentration, 80ml / L hydrochloric acid concentration, 180ml / L nitric acid concentration, 45g / L sodium hypochlorite concentration, and 20mL / L glacial acetic acid concentration, so that the production efficiency is maximized and greater economic benefits are obtained.

[0033] Research process of the present invention: Determination of etching temperature: like Figure 1 As shown in the figure, the etching speed of Fe-Ni alloy at different temperatures. It can be clearly seen that as the temperature increases, the etching speed increases. This is because as long as the temperature increases, the energy of the reaction particles increases. 3+ The chance of reacting with Fe, Ni and other atoms on the sample surface increases, and the reaction rate also increases. As the temperature rises further, hydrochloric acid, nitric acid and other components in the solution will escape into the air, endangering the human body and the environment. If the temperature is below 20 degrees, a refrigeration system may be required for control. Therefore, taking into account the actual situation of the factory, when the reaction temperature is too high, it will not only increase the difficulty of reaction control, but also increase resource consumption and cost. Therefore, through experiments, it is determined that the optimal etching temperature of the ferric chloride etching solution is set at 40 ℃.

[0034] like Figure 2 As shown in the figure, it is a curve of the effect of ferric chloride concentration on etching rate. As can be seen from the figure, with the increase of ferric chloride concentration, the etching rate increases significantly, but when the concentration exceeds 45wt%, the etching rate increases gradually. This is because a higher concentration of Fe³⁺ can provide more oxidants, accelerating the metal surface and Fe 3+ The metal (such as iron and nickel) is oxidized and dissolved faster to form Fe 2+ and metal ions (such as Ni 2+ However, when the concentration of ferric chloride is too high, the viscosity of the etching solution increases, resulting in a slow etching rate. 3+ It may cause over-oxidation and side reactions. For example, the generated metal oxides or salts may be deposited on the metal surface to form a passivation layer, which hinders the further etching and reduces the etching efficiency. When the concentration is too low, it may cause uneven etching and too slow etching rate, especially in the case of large surface area or complex geometry, and incomplete etching may occur. Therefore, the concentration of ferric chloride is more suitable at 40wt%.

[0035] Determination of nitric acid concentration in etching solution: like Figure 3As shown in the figure, the effect of nitric acid concentration in the etching solution on the etching speed at a temperature of 40°C. It can be seen from the figure that when the nitric acid concentration is less than 130ml / L, the etching speed increases slowly, and when the nitric acid concentration is greater than 130ml / L, the etching speed increases rapidly; when the nitric acid concentration is 60ml / L, the etching speed is 6μm / min, and when the nitric acid concentration is 240ml / L, the etching speed is 40μm / min, indicating that nitric acid can accelerate the etching of iron-nickel alloy. Nitric acid itself is a highly oxidizing acid and is the main oxidant in the etching solution. Its etching ability for iron-nickel alloy is not strong when used alone, but when it is dissolved with FeCl3, it plays a synergistic role in the etching of stainless steel, thereby greatly accelerating the etching speed. However, when the nitric acid concentration is too high, uneven etching will result, especially when the oxidizing effect of nitric acid is too strong, it will cause local accelerated corrosion. This uneven corrosion will produce rough textures on the metal surface, affecting the etching accuracy and product quality, and even destroying the integrity of the material in severe cases. Therefore, when the concentration of nitric acid is 180mL / L, the corrosion rate is moderate and the surface quality is good.

[0036] Determination of hydrochloric acid concentration in etching solution: like Figure 4 As shown in the figure, the effect of hydrochloric acid concentration on etching speed at 40°C. When the hydrochloric acid concentration is 40ml / L to 120ml / L, the etching speed increases rapidly. This is because the solution contains a large amount of nitric acid. When hydrochloric acid is added, it reacts with hydrochloric acid to generate NOCl, which is a much stronger oxidant than nitric acid, so it plays a role in rapid etching of stainless steel. When the hydrochloric acid concentration is greater than 80ml / L, the etching speed slowly decreases. This is because a high concentration of chloride ions will be generated during the reaction, and the generated Fe 2+ 、Ni 2+ It plays a complexing role. It makes mass transfer at the reaction interface difficult, thus reducing the reaction rate. Compared with the change of HCl concentration, the etching rate does not change much, which shows that hydrochloric acid has little effect on the etching rate. However, the concentration of hydrochloric acid can affect the surface structure of the iron-nickel alloy after etching. After the hydrochloric acid reaction, it can increase the specific surface area of ​​the alloy surface, thereby accelerating the reaction rate. Therefore, when the hydrochloric acid concentration is 80ml / L, the etching rate is the fastest.

[0037] Determination of sodium hypochlorite concentration in etching solution: like Figure 5 As shown in the figure, it is the relationship between the concentration of sodium hypochlorite in the etching solution and the etching rate at a temperature of 40°C. It can be seen from the figure that the etching rate gradually increases with the increase of sodium chlorate concentration. This is because sodium hypochlorite can react with the metal surface to generate metal oxides or metal ions through its strong oxidizing effect. This oxidation process will accelerate the dissolution rate of the metal, thereby increasing the etching rate. At the same time, sodium hypochlorite can effectively oxidize elements such as Fe and Ni, promoting Fe3+ and Ni 2+ The formation of chlorine gas accelerates the dissolution of the iron-nickel alloy and directly affects the improvement of the etching rate. However, although sodium hypochlorite can significantly increase the etching rate, excessive oxidizing properties will cause the etching surface to become rough, and the metal surface will be over-oxidized or partially unevenly corroded, thus affecting the etching quality. Therefore, the content of sodium hypochlorite should be controlled at 45g / L.

[0038] like Figure 6 As shown in the figure, it is the relationship curve between acetic acid concentration and etching rate. It can be seen from the figure that when the acetic acid concentration is low, the etching rate first increases, but as the concentration increases further, the etching rate decreases significantly. This is because acetic acid is an organic weak acid and can act as a pH regulator in the etching solution. Etching reactions often require an acidic environment to promote the dissolution and oxidation reaction of metals. As the concentration of acetic acid increases, the acidity of the etching solution may increase, thereby promoting the etching reaction. However, the acidity of acetic acid is relatively weak, and it will not increase the etching rate as drastically as strong acids (such as hydrochloric acid or nitric acid). Therefore, the increase of acetic acid may have a certain accelerating effect, but it will not be very significant. However, as the acetic acid content increases further, acetic acid will form metal-acetic acid complexes with certain metal ions (such as iron and nickel). The formation and separation of these complexes on the metal surface will affect the etching rate. The formation of the complex may temporarily inhibit the further corrosion of the metal, so when the acetic acid content is high, the etching rate is significantly reduced, showing the characteristics of a corrosion inhibitor. In this study, glacial acetic acid is mainly used as a corrosion inhibitor to control the etching rate so that the etching speed will not be too fast. Therefore, the acetic acid content of 20mL / L can meet the use requirements.

[0039] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above implementation is only to illustrate the technical concept and features of the present invention, and its purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and it cannot be used to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A fast and stable etching solution for iron-nickel alloy, characterized in that: The method comprises 30-40 wt % of trivalent iron salt, 80-140 mL / L of the first strong acid concentration, 20-60 mL / L of the second strong acid concentration, 20-50 g / L of oxidant, 10-40 mL / L of corrosion inhibitor and 15-30 ml / L of complexing agent.

2. The fast and stable iron-nickel alloy etching solution according to claim 1, characterized in that: Ultrapure deionized water was also included.

3. The fast and stable iron-nickel alloy etching solution according to claim 1, characterized in that: The trivalent iron salt is ferric chloride.

4. The fast and stable iron-nickel alloy etching solution according to claim 1, characterized in that: The first strong acid is hydrochloric acid, and the second strong acid is nitric acid.

5. The fast and stable iron-nickel alloy etching solution according to claim 1, characterized in that: The oxidant is sodium hypochlorite, the corrosion inhibitor is glacial acetic acid, and the complexing agent is ethylenediaminetetraacetic acid.

6. The fast and stable iron-nickel alloy etching solution according to claim 1, characterized in that: The concentration of sodium hypochlorite is 40 g / L, and the concentration of glacial acetic acid is 20 ml / L.

7. A method for producing a fast and stable etching solution for an iron-nickel alloy, characterized in that: The etching temperature is 40°C; the etching time is 10-60 minutes.

8. The working method of a fast and stable iron-nickel alloy etching solution according to claim 7, characterized in that: During the etching process, the etching solution is stirred evenly to avoid uneven etching due to different local chemical reaction rates.

9. The working method of a fast and stable iron-nickel alloy etching solution according to claim 7, characterized in that: Before etching, make sure the surface of the iron-nickel alloy is clean and free of grease, oxides or other impurities to ensure the uniformity and consistency of the etching effect; after etching, remove the workpiece from the etching solution and thoroughly clean it to remove residual chemicals to prevent continued reaction or surface contamination.

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