阅读说明：本技术 一种蚀刻液及其制备方法和应用 (Etching solution and preparation method and application thereof ) 是由 颜光明 雷霆 詹振翔 吕依芮 于 2020-11-23 设计创作，主要内容包括：本发明公开了一种蚀刻液及其制备方法和应用,蚀刻液包括以下组分：硝酸、氟离子源、缓蚀剂和溶剂；缓蚀剂为聚合物缓蚀剂。本发明的蚀刻液应用于钛及其合金的蚀刻工艺,包括以下步骤：(1)将钛及其合金的待蚀刻金属板进行覆膜处理；(2)在覆膜后的金属板上覆盖底片进行曝光处理,并对曝光后的金属板进行显影；(3)对显影后的金属板使用蚀刻液进行喷淋蚀刻,得到最终成品。本发明的蚀刻液易于制备,蚀刻液及蚀刻方法可实现精密蚀刻,还可减少对操作人员的伤害以及对环境的污染；且具有更大范围的操作温度。(The invention discloses an etching solution and a preparation method and application thereof, wherein the etching solution comprises the following components: nitric acid, a fluoride ion source, a corrosion inhibitor and a solvent; the corrosion inhibitor is a polymer corrosion inhibitor. The etching solution is applied to the etching process of titanium and titanium alloy, and comprises the following steps: (1) carrying out film coating treatment on a metal plate to be etched of titanium and titanium alloy; (2) covering a film on the coated metal plate, carrying out exposure treatment, and developing the exposed metal plate; (3) and (4) carrying out spray etching on the developed metal plate by using an etching solution to obtain a final finished product. The etching solution is easy to prepare, can realize precise etching, and can reduce the harm to operators and the pollution to the environment; and has a greater range of operating temperatures.)

1. The etching solution is characterized by comprising the following components: nitric acid, a fluoride ion source, a corrosion inhibitor and a solvent; the corrosion inhibitor is a polymer corrosion inhibitor.

2. The etching solution of claim 1, wherein the polymeric corrosion inhibitor is one or more of poly-cellulose, polyepoxysuccinic acid and polyvinylpyrrolidone.

3. The etching solution of claim 1, wherein the concentration of the polymeric corrosion inhibitor in the etching solution is 0.2g/L to 2 g/L.

4. The etching solution of claim 1, wherein the fluoride ion source is an ammonium bifluoride solid.

5. The etching solution of any one of claims 1 to 4, wherein the nitric acid in the etching solution accounts for 7 to 30 percent of the total volume of the etching solution, and the concentration of the fluoride ion source in the etching solution is 50 to 400 g/L.

6. A method for preparing an etching solution according to any one of claims 1 to 5, comprising the steps of:

(1) slowly adding the polymer corrosion inhibitor into a solvent under the stirring condition until the polymer corrosion inhibitor is completely dissolved to obtain a mixed solution;

(2) and adding the fluoride ion source and nitric acid into the mixed solution, and continuously stirring for 20-60 min to obtain the etching solution.

7. Use of the etching solution according to claims 1 to 5 or the etching solution obtained by the preparation method according to claim 6, wherein the etching solution is used in an etching process of titanium or an alloy thereof.

8. Use according to claim 7, wherein the etching process comprises in particular the steps of:

(1) carrying out film coating treatment on the metal plate to be etched of the titanium or the titanium alloy;

(2) covering a film on the coated metal plate for exposure treatment, and developing the exposed metal plate;

(3) and carrying out spray etching on the developed metal plate by using the etching solution, and carrying out post-treatment to obtain a final finished product.

9. The use of claim 8, wherein the spray pressure of the spray etching in step (3) is 1.5-3 kg/cm²。

10. The use of claim 8, wherein the spraying temperature of the spray etching in the step (3) is 25-60 ℃ and the spraying time is 3-10 min.

Technical Field

The invention relates to the technical field of wet etching, in particular to an etching solution and a preparation method and application thereof.

Background

Titanium is an important structural metal developed in the 50 s of the 20 th century, and titanium alloy is widely used in various fields due to the characteristics of high strength, good corrosion resistance, high heat resistance and the like. Titanium alloys are alloys based on titanium with other elements added. Titanium and its alloy have the characteristics of high strength and good corrosion resistance, so the etching processing is difficult, and the requirements on etching solution and etching process are high.

The prior etching technology has the following defects and shortcomings:

(1) in the prior art, wet etching is generally adopted, and has the limitation of isotropic etching, the aperture obtained by etching cannot be smaller than the thickness of a workpiece, the aperture is generally 1.2 to 2 times of the thickness of the workpiece, the side etching amount is large, the tolerance is difficult to control, and the precise etching is difficult to realize.

(2) In the prior art, etching solution consisting of hydrofluoric acid and nitric acid is generally adopted, a large amount of nitrogen oxides volatilize in the etching process, and theoretically, 4mol of nitrogen oxides are generated for every 1mol of titanium etched. Such Nitrogen Oxides (NO)₂) Is irritant gas, has high toxicity, causes harm to the body of an operator on one hand, and causes a great deal of pollution to the environment on the other hand. Meanwhile, the prior art needs to pay attention to temperature control during etching, because the volatilization amount of nitrogen oxide is larger at high temperature, so the service temperature of the prior art cannot exceed 40 ℃.

Disclosure of Invention

The invention provides an etching solution and a preparation method and application thereof, and aims to solve the problems of low etching precision, limited operation temperature and easy generation of pollution gas in the etching process in the prior etching technology.

In order to solve the technical problems, the invention adopts the following technical scheme:

an etching solution comprises the following components: nitric acid, a fluoride ion source, a corrosion inhibitor and a solvent; the corrosion inhibitor is a polymer corrosion inhibitor.

The technical scheme is that the polymer corrosion inhibitor is added into the etching solution, and can be preferentially adsorbed on the side wall of the etching seam in a specific process for etching metal, such as a pressure spray etching process, so that the etching speed of the side surface of the etching seam is effectively reduced, the isotropic etching limitation of wet etching is broken through, anisotropic etching is realized to a certain extent, the width and tolerance of the etching seam can be accurately controlled, and precise etching is realized.

Preferably, the polymer corrosion inhibitor is one or more of poly-cellulose, polyepoxysuccinic acid and polyvinylpyrrolidone. After repeated research and multiple tests, the inventor confirms the optimal preferred scheme of the polymer corrosion inhibitor, the three corrosion inhibitors are screened from a plurality of water-soluble polymers through a large number of experiments, compared with other polymer corrosion inhibitors, the corrosion inhibitor has better physical adsorption effect on titanium alloy, can ensure the smooth implementation of the whole etching technical scheme, can enable the side wall of an etching hole to be straighter, reduces burrs of the etching hole and improves the etching precision.

Preferably, the concentration of the polymer corrosion inhibitor in the etching solution is 0.2 g/L-2 g/L. The inventor researches and discovers that when the concentration of the polymer is lower than 0.2g/L, the corrosion inhibition effect is insufficient, the side corrosion is increased, the etching precision cannot be ensured, and the etching failure can be even caused more seriously; when the concentration of the polymer corrosion inhibitor is too high, the corrosion inhibition effect on titanium and titanium alloy is too strong, so that the etching time is too long, and the cost is increased; therefore, the polymer corrosion inhibitor within the concentration range of 0.2-2 g/L can meet the etching requirements of titanium alloys of different types and different thicknesses.

Preferably, the fluoride ion source is ammonium bifluoride. The preferred method selects ammonium bifluoride as the fluoride ion source in the etching solution instead of hydrofluoric acid in the prior art, and can reduce the generation of nitrogen oxide to the maximum extent (the concentration of the generated nitrogen oxide is less than 2 mg/m)³) Thereby reducing the harm to operators and the pollution to the environment; meanwhile, the etching solution using ammonium bifluoride as the fluoride ion source has a wider range of operating temperature, which can reach 60 ℃ at most (40 ℃ is common in the prior art).

Preferably, the nitric acid in the etching solution accounts for 7-30% of the total volume of the etching solution, and the concentration of the fluoride ion source in the etching solution is 50-400 g/L. Nitric acid is an oxidizing acid, and the purpose of adding nitric acid is three: one is to add hydrogen ions to the system, the other is to moderate the corrosion process of fluorine ions, and the third is that sufficient nitric acid can inhibit the hydrogen embrittlement phenomenon of titanium metal. Therefore, the proportion of the nitric acid and the fluoride ion source is required to meet the requirement of the etching rate, and the amount of the nitric acid is required to ensure that the etched titanium metal does not generate hydrogen embrittlement.

Based on the same technical concept, the invention also provides a preparation method of the etching solution, which comprises the following steps:

(1) slowly adding the polymer corrosion inhibitor into the solvent under the stirring condition until the polymer corrosion inhibitor is completely dissolved to obtain a mixed solution;

(2) and adding a fluoride ion source and nitric acid into the mixed solution, and continuously stirring for 20-60 min to obtain the etching solution.

Based on the same technical concept, the invention also provides application of the etching solution in the technical scheme, and the etching solution is used for etching titanium or titanium alloy by a spray etching process.

The technical idea of the technical scheme is that the polymer corrosion inhibitor in the etching solution can be preferentially adsorbed on the side wall of the etching seam under the pressure of spray etching by matching the spray etching process with the etching solution, so that the lateral etching speed is greatly reduced, and the anisotropic etching is realized to a certain extent. For example, etched striped through holes with a slit width of 0.12mm and a tolerance of less than 0.01mm were obtained on a TA2 titanium alloy sheet material with a thickness of 0.15 mm.

Preferably, the application of the etching solution specifically includes the following steps:

(1) carrying out film coating treatment on a metal plate to be etched of titanium or titanium alloy;

(2) covering a film on the coated metal plate, carrying out exposure treatment, and developing the exposed metal plate;

(3) and (4) carrying out spray etching on the developed metal plate by using an etching solution, and carrying out post-treatment to obtain a final finished product.

Preferably, the spraying pressure of the spraying etching operation in the step (3) is 1.5-3 kg/cm². The inventor researches and discovers that the etching product with the most accurate seam width can be obtained by the spray etching operation within the pressure range, and the polymer corrosion inhibitor cannot be preferentially attached to the side wall of the seam due to the excessively low spray pressure, so that the accuracy of the seam width is not enough; too high a spray pressure can lead to uncertainty in the distribution of the polymeric corrosion inhibitor, resulting in increased crevice tolerances.

Preferably, the spraying temperature of the spraying etching operation in the step (3) is 25-60 ℃. The higher the temperature, the higher the etching rate, the greater the etching rate has a great influence on the etching effect, and the lateral etching amount becomes larger both too fast and too slow.

Preferably, the spraying time of the spraying etching operation in the step (3) is 3-10 min. The spraying time is determined by the etching rate, the etching time is only required to be enough to enable the titanium metal to form the through hole, the through hole cannot be formed when the spraying time is too short, and the lateral erosion amount is increased and the etching precision is reduced when the spraying time is too long.

Preferably, in the step (3), the spraying angle in the spraying etching operation is perpendicular to the metal plate to be etched. The spraying angle is adjusted to be perpendicular to the metal plate to be etched, so that the polymer corrosion inhibitor can be better and preferentially attached to the side wall of the etching hole, and the etching precision is improved.

Preferably, the post-treatment in step (3) includes a film removal operation and a cleaning operation.

Compared with the prior art, the invention has the advantages that:

(1) the etching solution can break through the isotropic etching limitation of wet etching by matching with a specific process, and realizes precise etching; can also minimize the generation of nitrogen oxide during the etching process (the concentration of the generated nitrogen oxide is less than 2 mg/m)³) Thereby reducing the harm to operators and the pollution to the environment; according to the inventionCompared with the prior art, the etching solution has a wider operating temperature range which can reach 60 ℃ at most.

(2) The etching solution has simple preparation method, does not need complex equipment and process, and is suitable for large-scale industrial production.

(3) The etching method of the invention can break through the isotropic etching limitation of wet etching, realize anisotropic etching to a certain extent, accurately control the width of the etching slit and the tolerance, and realize precise etching.

Drawings

FIG. 1 is a view of a titanium metal etching product of example 1.

Detailed Description

The invention is described in further detail below with reference to the figures and specific examples.

Example 1:

the etching solution of the embodiment comprises nitric acid, ammonium bifluoride, a hydroxyethyl cellulose polymer corrosion inhibitor and water; wherein the concentration of the hydroxyethyl cellulose in the etching solution is 1.5g/L, the volume fraction of the nitric acid in the etching solution is 12%, and the concentration of the ammonium bifluoride in the etching solution is 100 g/L.

The preparation method of the etching solution of the embodiment comprises the following steps:

(1) adding hydroxyethyl cellulose as a polymer corrosion inhibitor into water under the condition of vigorous stirring, and obtaining a mixed solution after the polymer corrosion inhibitor is completely dissolved;

(2) and (3) continuously adding fluoride ion sources of ammonium bifluoride and nitric acid into the mixed solution, and continuously stirring for 30min to obtain uniform and stable etching solution.

The etching solution of the embodiment can be applied to the etching process of titanium and titanium alloy, and specifically comprises the following steps:

(1) pretreatment and cleaning: sequentially carrying out alkali washing, electrolytic oil removal, acid washing, water washing and drying on a TA2 titanium plate (with the thickness of 0.15 mm);

(2) roll coating: carrying out film coating treatment on the titanium plate after pretreatment and cleaning, carrying out roller coating by using ink mainly comprising resin and a photosensitizer, and drying the titanium plate by using a tunnel furnace after a protective layer of the ink is coated in a roller manner, wherein the thickness of a coating film is 20-40 micrometers;

(3) exposure: putting the titanium plate into a film negative (a workpiece design drawing is on the negative), and exposing by using an exposure machine;

(4) and (3) developing: developing and drying the exposed titanium plate by using 1% sodium bicarbonate, and developing the pattern to be etched;

(5) etching: the developed titanium plate was placed in an etching machine, and the etching solution of this example was used for spray etching with a spray pressure of 2.5kg/cm²Spraying at 35 deg.C for 5min to form etched through hole;

(6) removing the film: and soaking the etched product in 10% sodium hydroxide solution at 80 ℃ for 1 hour to enable the protective layer to fall off, and then carrying out acid washing, water washing and drying in sequence to finish the etching process of the titanium metal plate.

The etched titanium metal plate is detected on a quadratic element detector, as shown in fig. 1, the edge of an etched seam of the product is straight and sharp, the width of the etched seam is 0.122mm, the tolerance is 0.007mm and less than 0.01mm, and the aperture size obtained by etching is less than the thickness (0.15mm) of a workpiece, so that the design requirement is met.

Example 2:

the etching solution of the embodiment comprises nitric acid, ammonium bifluoride, a polyvinylpyrrolidone polymer corrosion inhibitor and water; wherein the concentration of the polyvinylpyrrolidone in the etching solution is 0.8g/L, the volume fraction of the nitric acid in the etching solution is 15%, and the concentration of the ammonium bifluoride in the etching solution is 150 g/L.

The preparation method of the etching solution of the embodiment comprises the following steps:

(1) adding polyvinylpyrrolidone serving as a polymer corrosion inhibitor into water under the condition of vigorous stirring, and obtaining a mixed solution after the polymer corrosion inhibitor is completely dissolved;

(2) and (3) continuously adding fluoride ion sources of ammonium bifluoride and nitric acid into the mixed solution, and continuously stirring for 40min to obtain uniform and stable etching solution.

The etching solution of the embodiment can be applied to the etching process of titanium and titanium alloy, and specifically comprises the following steps:

(1) pretreatment and cleaning: sequentially carrying out alkali washing, electrolytic oil removal, acid washing, water washing and drying on a TA2 titanium plate (with the thickness of 0.20 mm);

(2) roll coating: carrying out film coating treatment on the titanium plate after pretreatment and cleaning, carrying out roller coating by using ink mainly comprising resin and a photosensitizer, and drying the titanium plate by using a tunnel furnace after a protective layer of the ink is coated in a roller manner, wherein the thickness of a coating film is 20-40 micrometers;

(3) exposure: putting the titanium plate into a film negative (a workpiece design drawing is on the negative), and exposing by using an exposure machine;

(4) and (3) developing: developing and drying the exposed titanium plate by using 1% sodium bicarbonate, and developing the pattern to be etched;

(5) etching: the developed titanium plate was placed in an etching machine, and the etching solution of this example was used for spray etching with a spray pressure of 2.0kg/cm²Spraying at 45 deg.C for 6min to form etched through hole;

(6) removing the film: and soaking the etched product in 10% sodium hydroxide solution at 80 ℃ for 1 hour to enable the protective layer to fall off, and then carrying out acid washing, water washing and drying in sequence to finish the etching process of the titanium metal plate.

And (3) detecting the etched titanium metal plate on a quadratic element detector, wherein the width of an etching slit is 0.150mm, the tolerance is less than 0.01mm, and the aperture size obtained by etching is less than the thickness (0.20mm) of the workpiece, so that the design requirement is met.

Example 3:

the etching solution of the embodiment comprises nitric acid, ammonium bifluoride, polyepoxysuccinic acid polymer corrosion inhibitor and water; wherein the concentration of the polyepoxysuccinic acid in the etching solution is 0.2g/L, the volume fraction of the nitric acid in the etching solution is 18 percent, and the concentration of the ammonium bifluoride in the etching solution is 200 g/L.

The preparation method of the etching solution of the embodiment comprises the following steps:

(1) adding a polymer corrosion inhibitor polyepoxysuccinic acid into water under the condition of vigorous stirring, and obtaining a mixed solution after the polymer corrosion inhibitor is completely dissolved;

(2) and (3) continuously adding fluoride ion sources of ammonium bifluoride and nitric acid into the mixed solution, and continuously stirring for 60min to obtain uniform and stable etching solution.

The etching solution of the embodiment can be applied to the etching process of titanium and titanium alloy, and specifically comprises the following steps:

(1) pretreatment and cleaning: sequentially carrying out alkali washing, electrolytic oil removal, acid washing, water washing and drying on a TC4 titanium alloy plate (with the thickness of 0.30 mm);

(2) roll coating: carrying out film coating treatment on the titanium plate after pretreatment and cleaning, carrying out roller coating by using ink mainly comprising resin and a photosensitizer, and drying the titanium plate by using a tunnel furnace after a protective layer of the ink is coated in a roller manner, wherein the thickness of a coating film is 20-40 micrometers;

(3) exposure: putting the titanium plate into a film negative (a workpiece design drawing is on the negative), and exposing by using an exposure machine;

(4) and (3) developing: developing and drying the exposed titanium plate by using 1% sodium bicarbonate, and developing the pattern to be etched;

(5) etching: the developed titanium plate was placed in an etching machine, and spray etching was carried out using the etching solution of this example, with the spray pressure set at 3.0kg/cm²Spraying at 60 deg.C for 6min to form etched through hole;

(6) removing the film: and soaking the etched product in 10% sodium hydroxide solution at 80 ℃ for 1 hour to enable the protective layer to fall off, and then carrying out acid washing, water washing and drying in sequence to finish the etching process of the titanium metal plate.

And (3) detecting the etched titanium metal plate on a quadratic element detector, wherein the width of an etching slit is 0.22mm, the tolerance is less than 0.01mm, and the aperture size obtained by etching is less than the thickness (0.30mm) of the workpiece, so that the design requirement is met.

Comparative example 1:

the etching solution of the comparative example comprises the following components in volume fraction: 15% nitric acid and 5% hydrofluoric acid, and the solvent is water.

The etching solution of the comparative example can be applied to the etching process of titanium and titanium alloy, and specifically comprises the following steps:

(1) carrying out pretreatment, roll coating, exposure and development on a TA2 titanium alloy plate (with the thickness of 0.15mm) to be etched;

(2) carrying out common spray etching on the treated TA2 titanium alloy plate;

(3) and (4) removing the film and cleaning the etched titanium alloy plate.

And detecting the etched through hole of the etched titanium alloy plate, wherein the detection shows that the edge of the etched through hole is in a sawtooth shape, a large number of burrs are formed, the seam width is 0.185mm, the thickness of the etched through hole is 0.15mm larger than that of the titanium alloy plate, and the tolerance is 0.03 mm.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-described embodiments. Modifications and variations that may occur to those skilled in the art without departing from the spirit and scope of the invention are to be considered as within the scope of the invention.