CN-122017123-A - Method for detecting content of peroxodisulfate in copper acid etching liquid

Abstract

The invention provides a method for detecting the content of peroxodisulfate in a copper acid etching solution, which comprises the following steps of sequentially adding an acid solution and a ferrous salt solution into the copper acid etching solution, uniformly mixing, titrating by using a potassium permanganate standard titration solution, determining the consumption volume of the solution to be V1, taking the acid solution and the ferrous salt solution with the same specification and volume as blank control, uniformly mixing, titrating by using the potassium permanganate standard titration solution, determining the consumption volume of the solution to be V0, and calculating the content of peroxodisulfate in the copper acid etching solution according to the difference value between V0 and V1. The method has the advantages of simple and easily obtained reagent, low price, simple testing method, high data stability and repeatability, simple required instrument and low cost, and can realize the rapid and accurate detection of the content of the peroxodisulfate in the copper acid etching liquid.

Inventors

• Yu Lvlv
• WEI CHUNLEI
• LI CHUANG
• ZHANG HONGWEI
• HUANG HAIDONG
• HU TIANQI

Assignees

• 南京和显达微电子科技有限公司

Dates

Publication Date

20260512

Application Date

20260210

Claims (10)

1. 1. The method for detecting the content of the peroxodisulfate in the copper acid etching liquid is characterized by comprising the following steps of: Sequentially adding acid liquor and ferrous salt solution into the copper acid etching solution, uniformly mixing, titrating by using potassium permanganate standard titration solution, and measuring the consumption volume of the solution to be V1; taking the acid solution and the ferrous salt solution with the same specification and volume as blank control, uniformly mixing, and then titrating by using the potassium permanganate standard titration solution to determine the consumption volume as V0; The calculation formula of the content of the persulfate in the copper acid etching solution is as follows: The mass concentration of the substance; M is molecular weight; and m is the mass of the copper acid etching liquid.
2. 2. The method of claim 1, wherein the acid solution comprises dilute sulfuric acid.
3. 3. The detection method according to claim 1 or 2, wherein the mass concentration of the acid solution is 1-5%.
4. 4. The method according to any one of claims 1 to 3, wherein the acid solution is added to a final pH of 0 to 3.
5. 5. The method according to any one of claims 1 to 4, wherein the ferrous salt solution comprises a ferrous ammonium sulfate solution.
6. 6. The method according to any one of claims 1 to 5, wherein the concentration of the ferrite solution is 0.05 to 0.5 mol/L.
7. 7. The method according to any one of claims 1 to 6, wherein the concentration of the potassium permanganate standard titration solution is 0.3-0.7 mol/L.
8. 8. The method according to any one of claims 1 to 7, wherein a molar ratio of ferrous ions in the ferrous salt solution to persulfate ions in the copper acid etching solution is greater than 2.
9. 9. The method according to any one of claims 1 to 8, wherein the detected temperature is 15 to 30 ℃.
10. 10. The method according to any one of claims 1 to 9, wherein the detection is performed in parallel with 2 or more times.

Description

Method for detecting content of peroxodisulfate in copper acid etching liquid Technical Field The invention relates to the technical field of chemical analysis, in particular to a method for detecting the content of peroxodisulfate in a copper acid etching solution. Background The copper acid etching liquid is complex, contains high-concentration copper ions, hydrogen ions, various halogen ions and other impurities, and the existing detection method is easy to interfere in the complex system, so that the detection accuracy, the operation simplicity and the environmental friendliness are difficult to be achieved. Therefore, developing a persulfate content detection method which is simple and easy to obtain reagents, simple and convenient to operate, low in detection cost, environment-friendly and suitable for a complex system of copper acid etching solution becomes a technical problem to be solved in the current industrial production. Since peroxodisulfate is a key oxidant for maintaining etching rate and uniformity, the fluctuation of concentration directly affects etching quality and production yield of Printed Circuit Boards (PCBs) or precise parts, so that the peroxodisulfate has important practical significance for realizing rapid and accurate on-line or on-site monitoring of the peroxodisulfate, optimizing process control, stabilizing product quality, reducing chemical consumption and reducing pollution emission. At present, the method for detecting the content of the peroxodisulfate mainly comprises an ion chromatography method, a high performance liquid chromatography method, an iodometric titration method, a fluorescence photometry method and the like, but the methods have obvious limitations when being applied to a complex etching solution system. 1. Ion chromatography and high performance liquid chromatography have strong separation capability and high detection accuracy, but the required instruments (such as high performance liquid chromatography) are expensive, the unit price is usually more than hundreds of thousands yuan, and the daily operation and maintenance costs are also quite low. Meanwhile, the methods are complicated in pretreatment, long in analysis period and high in requirements on professional skills of operators, and large instruments are difficult to move and deploy. Therefore, the method is more suitable for off-line precision analysis in a laboratory, and cannot meet the real-time, rapid and convenient field detection requirements of an industrial production line; 2. Iodometric titration is a traditional method that is more commonly used in industrial sites. The principle is that iodide ions are oxidized into iodine simple substance under the acidic condition by utilizing the strong oxidizing property of the peroxodisulfate, and then the iodine simple substance generated by titration of the sodium thiosulfate standard solution is used for indirectly calculating the content of the peroxodisulfate. However, the method has obvious defects that firstly, various chemical reagents such as potassium iodide, starch indicator, sodium thiosulfate and the like are needed, the steps are complicated, secondly, the judgment of the titration end point (blue fading) depends on subjective experience and visual discrimination of operators, human errors are easy to generate, the reproducibility is poor, a small amount of toxic iodine vapor can escape in the reaction process, potential threat is formed to the health of operators, secondary pollution to the working environment is possibly caused, and the method does not accord with the development concept of green chemistry; 3. The fluorescence photometry is based on the fluorescence signal change caused by the reaction of a specific fluorescent probe and peroxodisulfate, and has the advantage of high sensitivity in theory. However, the method has serious challenges in practical application, namely, on one hand, the specific fluorescent reagent with stable performance is difficult to synthesize and is high in price, and the problem of poor storage stability possibly exists, and on the other hand, the method is the most critical, and complex matrix components such as high-concentration copper ions (with fluorescence quenching effect) and chloride ions in the copper acid etching solution can generate serious fluorescence interference, so that the selectivity of the probe is reduced, the detection signal is distorted, and the accuracy and the reliability of an analysis result are seriously influenced. Therefore, the invention develops a detection strategy, aims to break through the interference barrier of the complex matrix, integrates multiple advantages of rapidness, simplicity, low cost, environmental friendliness and the like, and becomes a key technical breakthrough direction for promoting the fine control and the green development of the etching process. Disclosure of Invention In view of the problems in the prior art, the invention provides a m