Copper etching liquid and method of configuring same, etching method and use

Abstract

This invention provides a copper etching solution, its preparation method, etching method, and application. The copper etching solution comprises 1-30 parts cerium ammonium sulfate, 0-20 parts inorganic acid, 0-20 parts organic acid, and 0-90 parts water. The inorganic acid includes one or more of sulfuric acid, phosphoric acid, hypochlorous acid, chloric acid, boric acid, carbonic acid, nitric acid, nitrous acid, and hydrochloric acid. The organic acid includes one or more of citric acid, acetic acid, tartaric acid, malic acid, formic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, glycolic acid, acrylic acid, methacrylic acid, lactic acid, gluconic acid, maleic acid, benzoic acid, and salicylic acid. The copper etching solution of this invention exhibits good etching properties for copper and minimal damage to nickel-chromium alloys.

Description

Technical Field

[0001] This invention relates to the field of electronic chemical technology, and in particular to a copper etching solution, its preparation method, etching method, and application. Background Technology

[0002] Nickel-chromium alloys possess high resistivity and strain sensitivity coefficients, as well as excellent mechanical properties, making them a primary material for fabricating room-temperature and high-temperature strain gauges. The electrodes of this type of strain gauge require a copper metal layer to ensure excellent weldability. After the nickel-chromium alloy foil is laminated with a copper layer, the copper layer is used to form the strain gauge electrode pattern through photolithography. The etching of the copper metal layer during photolithography is crucial; it is necessary to form a complete electrode pattern without allowing the etching solution to corrode the nickel-chromium alloy layer and affect the strain gauge performance. Current technology lacks an etching solution suitable for etching the copper layer laminated on nickel-chromium alloys while minimizing damage to the nickel-chromium alloy.

[0003] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0004] This invention provides a copper etching solution, its preparation method, etching method, and application, aiming to solve the technical problems mentioned in the background section of the prior art regarding copper etching solutions.

[0005] The contents of this invention are as follows:

[0006] The first aspect of the present invention provides a copper etching solution comprising 1-30 parts of cerium ammonium sulfate, 0-20 parts of inorganic acid, 0-20 parts of organic acid and 0-90 parts of water;

[0007] The inorganic acids include one or more of sulfuric acid, phosphoric acid, hypochlorous acid, chloric acid, boric acid, carbonic acid, nitric acid, nitrous acid, and hydrochloric acid;

[0008] The organic acids include one or more of citric acid, acetic acid, tartaric acid, malic acid, formic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, glycolic acid, acrylic acid, methacrylic acid, lactic acid, gluconic acid, maleic acid, benzoic acid, and salicylic acid.

[0009] In an optional embodiment of the first aspect of the present invention, the inorganic acid is one or more of nitric acid, hydrochloric acid, sulfuric acid, and phosphoric acid.

[0010] In an optional embodiment of the first aspect of the invention, the organic acid is one or more of citric acid, acetic acid, formic acid, lactic acid, and acrylic acid.

[0011] In one optional embodiment of the first aspect of the present invention, the mixture comprises, by mass ratio: 10 parts cerium ammonium sulfate, 5 parts hydrochloric acid, 5 parts acetic acid and 80 parts water.

[0012] A second aspect of the present invention provides a method for preparing a copper etching solution, comprising:

[0013] The facility provides ceric ammonium sulfate, inorganic acid, organic acid, and water, wherein, by mass ratio, ceric ammonium sulfate comprises 1-30 parts, inorganic acid 0-20 parts, organic acid 0-20 parts, and water 0-90 parts. The inorganic acid includes one or more of sulfuric acid, phosphoric acid, hypochlorous acid, chloric acid, boric acid, carbonic acid, nitric acid, nitrous acid, and hydrochloric acid. The organic acid includes one or more of citric acid, acetic acid, tartaric acid, malic acid, formic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, glycolic acid, acrylic acid, methacrylic acid, lactic acid, gluconic acid, maleic acid, benzoic acid, and salicylic acid.

[0014] A copper etching solution is obtained by mixing cerium ammonium sulfate, inorganic acid, organic acid and water evenly.

[0015] A third aspect of the present invention provides a method for etching a copper layer composite on a nickel-chromium alloy sheet, comprising the following steps:

[0016] Provides cerium ammonium sulfate, inorganic acids, organic acids, and water;

[0017] A copper etching solution is obtained by uniformly mixing cerium ammonium sulfate, inorganic acid, organic acid, and water. The solution comprises, by mass ratio, 1-30 parts cerium ammonium sulfate, 0-20 parts inorganic acid, 0-20 parts organic acid, and 0-90 parts water. The inorganic acid includes one or more of sulfuric acid, phosphoric acid, hypochlorous acid, chloric acid, boric acid, carbonic acid, nitric acid, nitrous acid, and hydrochloric acid. The organic acid includes one or more of citric acid, acetic acid, tartaric acid, malic acid, formic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, glycolic acid, acrylic acid, methacrylic acid, lactic acid, gluconic acid, maleic acid, benzoic acid, and salicylic acid.

[0018] The copper etching solution is used to etch the nickel-chromium alloy sheet with a composite copper layer after masking and development to obtain a nickel-chromium alloy sheet with a patterned copper layer.

[0019] In an optional embodiment of the third aspect of the present invention, the etching of the nickel-chromium alloy sheet of the composite copper layer after masking and development by the copper etching solution is carried out at room temperature for 20-30 minutes.

[0020] In an optional embodiment of the third aspect of the present invention, the etching of the nickel-chromium alloy sheet of the composite copper layer after masking and developing by the copper etching solution is carried out under heating conditions, and the etching time is 5-10 minutes.

[0021] In an optional embodiment of the third aspect of the present invention, the heating condition is 30~60°C.

[0022] The fourth aspect of this invention provides an application of a copper etching solution in the preparation of strain gauges based on nickel-chromium alloy sheets with composite copper layers, wherein the copper etching solution comprises, by mass, 1-30 parts of cerium ammonium sulfate, 0-20 parts of inorganic acid, 0-20 parts of organic acid and 0-90 parts of water;

[0023] The inorganic acids include one or more of sulfuric acid, phosphoric acid, hypochlorous acid, chloric acid, boric acid, carbonic acid, nitric acid, nitrous acid, and hydrochloric acid;

[0024] The organic acids include one or more of citric acid, acetic acid, tartaric acid, malic acid, formic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, glycolic acid, acrylic acid, methacrylic acid, lactic acid, gluconic acid, maleic acid, benzoic acid, and salicylic acid.

[0025] Beneficial Effects: This invention provides a copper etching solution, its preparation method, etching method, and application. The copper etching solution comprises 1-30 parts of cerium ammonium sulfate, 0-20 parts of inorganic acid, 0-20 parts of organic acid, and 0-90 parts of water. The inorganic acid includes one or more of sulfuric acid, phosphoric acid, hypochlorous acid, chloric acid, boric acid, carbonic acid, nitric acid, nitrous acid, and hydrochloric acid. The organic acid includes one or more of citric acid, acetic acid, tartaric acid, malic acid, formic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, glycolic acid, acrylic acid, methacrylic acid, lactic acid, gluconic acid, maleic acid, benzoic acid, and salicylic acid. The copper etching solution of the present invention is mainly composed of cerium ammonium sulfate and water, with the addition of inorganic acids such as nitric acid / hydrochloric acid / sulfuric acid / phosphoric acid, and organic acids such as formic acid / acetic acid / citric acid. It can effectively etch only copper metal to form the required pattern, while having little impact on nickel-chromium (Ni / Cr) alloys. The etching effect is excellent and the efficiency is high. Detailed Implementation

[0026] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention.

[0027] The first aspect of the present invention provides a copper etching solution comprising 1-30 parts of cerium ammonium sulfate, 0-20 parts of inorganic acid, 0-20 parts of organic acid, and 0-90 parts of water; wherein the inorganic acid comprises one or more of sulfuric acid, phosphoric acid, hypochlorous acid, chloric acid, boric acid, carbonic acid, nitric acid, nitrous acid, and hydrochloric acid; and wherein the organic acid comprises one or more of citric acid, acetic acid, tartaric acid, malic acid, formic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, glycolic acid, acrylic acid, methacrylic acid, lactic acid, gluconic acid, maleic acid, benzoic acid, and salicylic acid.

[0028] In a more specific embodiment of the present invention, the inorganic acid is one or more of nitric acid, hydrochloric acid, sulfuric acid, and phosphoric acid. The organic acid is one or more of citric acid, acetic acid, formic acid, lactic acid, and acrylic acid. By using the above-mentioned organic and inorganic acids, both etching efficiency and cost are balanced, making it more economical. In summary, the present invention proposes an etching solution for a nickel-chromium alloy composite metal copper layer. The etching solution exhibits excellent selectivity for metals, effectively corroding copper metal with complete and uniform etching patterns at high efficiency, while showing virtually no corrosion to the nickel-chromium alloy, ensuring the quality of products such as strain gauges.

[0029] In one exemplary embodiment of the copper etching solution of the present invention, the copper etching solution comprises, by mass ratio: 10 parts cerium ammonium sulfate, 5 parts hydrochloric acid, 5 parts acetic acid, and 80 parts water. In this embodiment, the proportions of cerium ammonium sulfate, hydrochloric acid, acetic acid, and acetic acid are only 20%, which greatly reduces the amount of cerium ammonium sulfate, hydrochloric acid, acetic acid, and acetic acid used, thus ensuring the etching effect while also taking into account the economy of the formulation.

[0030] A second aspect of the present invention provides a method for preparing a copper etching solution, comprising:

[0031] The facility provides ceric ammonium sulfate, inorganic acid, organic acid, and water, wherein, by mass ratio, ceric ammonium sulfate comprises 1-30 parts, inorganic acid 0-20 parts, organic acid 0-20 parts, and water 0-90 parts. The inorganic acid includes one or more of sulfuric acid, phosphoric acid, hypochlorous acid, chloric acid, boric acid, carbonic acid, nitric acid, nitrous acid, and hydrochloric acid. The organic acid includes one or more of citric acid, acetic acid, tartaric acid, malic acid, formic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, glycolic acid, acrylic acid, methacrylic acid, lactic acid, gluconic acid, maleic acid, benzoic acid, and salicylic acid.

[0032] A copper etching solution is obtained by uniformly mixing cerium ammonium sulfate, inorganic acid, organic acid, and water. In this invention, the order of adding cerium ammonium sulfate, inorganic acid, organic acid, and water is not fixed. However, for operational safety, water and cerium ammonium sulfate can be added first, followed by inorganic acid and organic acid. When adding inorganic acid and organic acid, the inner wall of the container can be used for drainage.

[0033] A third aspect of the present invention provides a method for etching a copper layer composite on a nickel-chromium alloy sheet, comprising the following steps:

[0034] Provides cerium ammonium sulfate, inorganic acids, organic acids, and water;

[0035] A copper etching solution is obtained by uniformly mixing cerium ammonium sulfate, inorganic acid, organic acid, and water. The solution comprises, by mass ratio, 1-30 parts cerium ammonium sulfate, 0-20 parts inorganic acid, 0-20 parts organic acid, and 0-90 parts water. The inorganic acid includes one or more of sulfuric acid, phosphoric acid, hypochlorous acid, chloric acid, boric acid, carbonic acid, nitric acid, nitrous acid, and hydrochloric acid. The organic acid includes one or more of citric acid, acetic acid, tartaric acid, malic acid, formic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, glycolic acid, acrylic acid, methacrylic acid, lactic acid, gluconic acid, maleic acid, benzoic acid, and salicylic acid.

[0036] The copper etching solution is used to etch the nickel-chromium alloy sheet with a composite copper layer after masking and development to obtain a nickel-chromium alloy sheet with a patterned copper layer.

[0037] In an optional embodiment of the third aspect of the present invention, the etching of the nickel-chromium alloy sheet of the composite copper layer after masking and development by the copper etching solution is carried out at room temperature for an etching time of 20-30 min, for example 20 min, 25 min and 30 min.

[0038] In an optional embodiment of the third aspect of the present invention, the etching of the nickel-chromium alloy sheet with the composite copper layer after masking and development by the copper etching solution is performed under heating conditions for a time of 5-10 minutes, such as 5 minutes, 7 minutes, and 10 minutes.

[0039] In an optional embodiment of the third aspect of the invention, the heating conditions are 30~60°C. For example, 30°C, 40°C, 45°C, 50°C, and 60°C.

[0040] The fourth aspect of this invention provides the application of a copper etching solution in the preparation of strain gauges based on nickel-chromium alloy sheets with composite copper layers. The copper etching solution, by mass parts, comprises 1-30 parts cerium ammonium sulfate, 0-20 parts inorganic acid, 0-20 parts organic acid, and 0-90 parts water. The inorganic acid includes one or more of sulfuric acid, phosphoric acid, hypochlorous acid, chloric acid, boric acid, carbonic acid, nitric acid, nitrous acid, and hydrochloric acid. The organic acid includes one or more of citric acid, acetic acid, tartaric acid, malic acid, formic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, glycolic acid, acrylic acid, methacrylic acid, lactic acid, gluconic acid, maleic acid, benzoic acid, and salicylic acid.

[0041] To better illustrate the effects of the technical solution of the present invention, the following embodiments and comparative examples were constructed to test the etching effect.

[0042] Example 1: The etching solution comprises 10 parts cerium ammonium sulfate, 5 parts nitric acid, 2 parts acetic acid, and 85 parts water, mixed evenly. It is then used to etch the developed composite metal sheet at room temperature for 20 minutes. The copper metal is completely etched, producing the desired pattern with smooth and flat edges. After the copper etching is complete, the underlying nickel-chromium (Ni / Cr) alloy layer is bright and smooth. This etching solution has minimal impact on the corrosion of the nickel-chromium (Ni / Cr) alloy.

[0043] Example 2: The etching solution comprises 10 parts cerium ammonium sulfate, 5 parts nitric acid, 6 parts acetic acid, and 79 parts water, mixed evenly. It is then used to etch the developed composite metal sheet at 40°C for 5 minutes. The copper metal is completely etched, producing the desired pattern with smooth and flat edges. After the copper etching is complete, the underlying nickel-chromium (Ni / Cr) alloy layer is bright and smooth. This etching solution has minimal impact on the corrosion of the nickel-chromium (Ni / Cr) alloy.

[0044] Example 3: The etching solution comprises 10 parts cerium ammonium sulfate, 5 parts nitric acid, 6 parts acetic acid, 5 parts citric acid, and 74 parts water. The mixture is thoroughly combined and used to etch the developed composite metal sheet at 40°C for 5 minutes. The copper metal is completely etched, producing the desired pattern with smooth and flat edges. After the copper etching is complete, the underlying nickel-chromium (Ni / Cr) alloy layer remains bright and smooth. This etching solution has minimal impact on the corrosion of the nickel-chromium (Ni / Cr) alloy.

[0045] Example 4: The etching solution comprises 10 parts cerium ammonium sulfate, 5 parts hydrochloric acid, 5 parts acetic acid, and 80 parts water, mixed evenly. It is then used to etch the developed composite metal sheet at 50°C for 5 minutes. The copper metal is completely etched, producing the desired pattern with smooth and flat edges. After the copper etching is complete, the underlying nickel-chromium (Ni / Cr) alloy layer is bright and smooth. This etching solution has minimal impact on the corrosion of the nickel-chromium (Ni / Cr) alloy.

[0046] Example 5: The etching solution comprises 10 parts cerium ammonium sulfate, 5 parts hydrochloric acid, 5 parts citric acid, and 80 parts water, mixed evenly. It is then used to etch the developed composite metal sheet at 50°C for 5 minutes. The copper metal is completely etched, producing the desired pattern with smooth and flat edges. After the copper etching is complete, the underlying nickel-chromium (Ni / Cr) alloy layer is bright and smooth. This etching solution has minimal impact on the corrosion of the nickel-chromium (Ni / Cr) alloy.

[0047] Example 6: The etching solution comprises 10 parts cerium ammonium sulfate, 5 parts sulfuric acid, 5 parts citric acid, and 80 parts water, mixed evenly. It is used to etch the developed composite metal sheet at 45°C for 5 minutes. The copper metal is completely etched, producing the desired pattern with smooth and flat edges. After the copper etching is complete, the underlying nickel-chromium (Ni / Cr) alloy layer is bright and smooth. This etching solution has minimal impact on the corrosion of the nickel-chromium (Ni / Cr) alloy.

[0048] Comparative Example 1: The etching solution contained 10 parts ferric chloride, 3 parts hydrochloric acid, and 87 parts water. They were mixed evenly to form an etching solution. The solution was used to etch the developed composite metal sheet at 40°C for 5 minutes. The copper metal was completely etched, and the desired pattern was etched out. The edges of the pattern were smooth and flat. However, the underlying nickel-chromium (Ni / Cr) alloy lost its metallic luster, and a passivation layer was formed on the surface. The surface was severely oxidized, which affected the product quality.

[0049] Comparative Example 2: The etching solution consisted of 8 parts hydrogen peroxide, 5 parts hydrochloric acid, and 87 parts water, mixed evenly to form an etching solution. This solution was used to etch the developed composite metal sheet at 40°C for 5 minutes. The copper metal was completely etched, producing the desired pattern with smooth and flat edges. However, the underlying nickel-chromium (Ni / Cr) alloy lost its metallic luster, a passivation layer formed on the surface, and was severely oxidized, leading to a decrease in product quality. The formulation parameters and results of each embodiment and comparative example are shown in Table 1 below. In Examples 1-6 of this invention, the copper layer lines etched on the nickel-chromium alloy sheet were uniform, and the corrosion of the nickel-chromium alloy was minimal.

[0050] Table 1. Formulation parameters and etching effects of various embodiments and comparative examples.

[0051]

[0052] In summary, this invention proposes an etching solution for nickel-chromium alloy composite copper layers. The etching solution has excellent selectivity for metals, can effectively corrode copper metal, and produces complete, uniform, and highly efficient etched patterns, while having virtually no corrosion on nickel-chromium alloys, thus ensuring the quality of products such as strain gauges.

[0053] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of etching a composite copper layer of a nickel-chromium alloy sheet material, characterized in that, Includes the following steps: Provides cerium ammonium sulfate, inorganic acids, organic acids, and water; A copper etching solution is prepared by uniformly mixing cerium ammonium sulfate, inorganic acid, organic acid, and water, wherein, by mass ratio: 10 parts cerium ammonium sulfate, 5 parts inorganic acid, 6 parts organic acid, and 79 parts water, wherein the inorganic acid is nitric acid and the organic acid is acetic acid; or, 10 parts cerium ammonium sulfate, 5 parts inorganic acid, 11 parts organic acid, and 74 parts water, wherein the inorganic acid is nitric acid, and the organic acids are acetic acid and citric acid, wherein acetic acid comprises 6 parts and citric acid comprises 5 parts; or, 10 parts cerium ammonium sulfate, 5 parts inorganic acid, 5 parts organic acid, and 80 parts water, wherein the inorganic acid is hydrochloric acid, and the organic acid is acetic acid or citric acid; or, 10 parts cerium ammonium sulfate, 5 parts inorganic acid, 5 parts organic acid and 80 parts water, wherein the inorganic acid is sulfuric acid and the organic acid is citric acid; The copper etching solution is used to etch the nickel-chromium alloy sheet with a composite copper layer after masking and development to obtain a nickel-chromium alloy sheet with a patterned copper layer.

2. The method of claim 1, wherein the nickel-chromium alloy sheet composite copper layer is etched by the acid solution. The etching of the nickel-chromium alloy sheet with the composite copper layer after masking and development is carried out at room temperature for 20-30 minutes using the copper etching solution.

3. The etching method for a nickel-chromium alloy sheet composite copper layer according to claim 1, characterized in that, The etching of the nickel-chromium alloy sheet with the composite copper layer after masking and development is carried out under heating conditions using the copper etching solution, and the etching time is 5-10 minutes.

4. The method of claim 3, wherein the nickel-chromium alloy sheet composite copper layer is etched by a solution containing 10 to 30 g / L of copper sulfate, 10 to 30 g / L of sulfuric acid, 10 to 30 g / L of hydrochloric acid, and 10 to 30 g / L of hydrogen peroxide. The heating conditions are 30~60℃.

5. Use of a copper etching liquid in the production of a strain gauge based on a nickel-chromium alloy sheet with a composite copper layer, characterized in that The copper etching solution, by mass parts: 10 parts cerium ammonium sulfate, 5 parts inorganic acid, 6 parts organic acid, and 79 parts water, wherein the inorganic acid is nitric acid and the organic acid is acetic acid; or, 10 parts cerium ammonium sulfate, 5 parts inorganic acid, 11 parts organic acid, and 74 parts water, wherein the inorganic acid is nitric acid, and the organic acids are acetic acid and citric acid, wherein acetic acid comprises 6 parts and citric acid comprises 5 parts; or, 10 parts cerium ammonium sulfate, 5 parts inorganic acid, 5 parts organic acid, and 80 parts water, wherein the inorganic acid is hydrochloric acid, and the organic acid is acetic acid or citric acid; or, The mixture consists of 10 parts cerium ammonium sulfate, 5 parts inorganic acid, 5 parts organic acid, and 80 parts water, wherein the inorganic acid is sulfuric acid and the organic acid is citric acid.

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