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CN-121992407-A - Composite corrosion inhibitor etching solution and preparation method and application thereof

CN121992407ACN 121992407 ACN121992407 ACN 121992407ACN-121992407-A

Abstract

The invention provides a composite corrosion inhibitor etching solution, a preparation method and application thereof, which realizes the selective removal of a copper seed layer under different etching conditions and effectively inhibits the transverse erosion and undercut phenomena of a copper electrode area by introducing a composite corrosion inhibition system consisting of a first corrosion inhibitor and a second corrosion inhibitor into an acid etching system, the etching solution of the invention has the advantages that the surface morphology is improved, the side etching depth is reduced, meanwhile, the complete etching of the residual copper seed layer in the non-electrode area is not influenced, and the two types of nitrogen-containing heterocyclic corrosion inhibitors generate a synergistic adsorption effect on the copper surface by utilizing the difference of molecular structures and adsorption behaviors, so that a compact and stable composite protective layer is formed, and the synergistic regulation and control of the overall corrosion rate and the local side etching behaviors are realized. The composite corrosion inhibitor etching solution has the advantages of good etching uniformity, obvious side etching inhibition effect, wide process window and suitability for industrialized application.

Inventors

  • ZHANG JINBING
  • ZHOU MINJIE
  • LEI QI
  • HU DONGLI
  • LI ZITONG

Assignees

  • 浙大宁波理工学院

Dates

Publication Date
20260508
Application Date
20260115

Claims (8)

  1. 1. The composite corrosion inhibitor etching solution is characterized by comprising the following components: oxidizing agent is potassium hydrogen persulfate composite salt; Acid is concentrated sulfuric acid; The composite corrosion inhibitor consists of a first corrosion inhibitor and a second corrosion inhibitor, wherein the first corrosion inhibitor is a nitrogen-containing heterocyclic compound capable of forming a covered adsorption film on the surface of copper, and the second corrosion inhibitor is a nitrogen-containing heterocyclic compound capable of being preferentially adsorbed on high-activity sites on the surface of copper; solvent, deionized water.
  2. 2. The composite corrosion inhibitor etching solution according to claim 1, wherein the first corrosion inhibitor is selected from one of methylbenzotriazole, phenanthroline and 5-methylbenzimidazole, and the second corrosion inhibitor is selected from one of imidazole, pyridine and pyrazole.
  3. 3. The composite corrosion inhibitor etching solution according to claim 1, wherein the mass ratio of the first corrosion inhibitor to the second corrosion inhibitor is (4-6): 1.
  4. 4. The composite corrosion inhibitor etching solution according to claim 1, wherein the concentration ranges of each component of the composite corrosion inhibitor etching solution are as follows: 15-25 g/L of potassium hydrogen persulfate composite salt; concentrated sulfuric acid 8-12 g/L; 0.2-0.3 g/L of first corrosion inhibitor; And the second corrosion inhibitor is 0.04-0.06 g/L.
  5. 5. The composite corrosion inhibitor etching solution according to claim 1, wherein the composite corrosion inhibitor etching solution comprises the following components in concentration: 20 g/L of potassium hydrogen persulfate composite salt; Concentrated sulfuric acid 10 g/L; 0.25 g/L of first corrosion inhibitor; and the second corrosion inhibitor is 0.05 g/L.
  6. 6. A method for preparing the composite corrosion inhibitor etching solution according to any one of claims 1 to 5, comprising the following steps: slowly adding concentrated sulfuric acid into deionized water under stirring and uniformly mixing; adding potassium hydrogen persulfate composite salt into the obtained solution and stirring until the potassium hydrogen persulfate composite salt is completely dissolved; Then adding a second corrosion inhibitor and stirring until the second corrosion inhibitor is completely dissolved; And finally adding the first corrosion inhibitor, and stirring until the first corrosion inhibitor is completely dissolved to obtain the composite corrosion inhibitor etching solution.
  7. 7. The use of the composite corrosion inhibitor etching solution according to any one of claims 1 to 5 in the removal of seed layers of copper gate heterojunction solar cells, comprising the steps of: A1, etching treatment, namely immersing the solar cell with the copper seed layer into the etching solution, and etching for 90+/-10 seconds at 20+/-10 ℃; a2, flushing the etched battery piece with deionized water until no etching liquid remains on the surface; And A3, drying the washed solar cell to obtain the solar cell with the copper seed layer removed.
  8. 8. The method according to claim 7, wherein in the step A1, the etching treatment is performed at 25℃for 90 seconds.

Description

Composite corrosion inhibitor etching solution and preparation method and application thereof Technical Field The invention relates to the technical field of preparation of composite corrosion inhibitors, in particular to a composite corrosion inhibitor etching solution, a preparation method and application thereof. Background In recent years, heterojunction (Heterojunction WITH INTRINSIC THIN LAYER, HJT) solar cells have been one of the important development directions in the photovoltaic field due to their excellent surface passivation performance, high photoelectric conversion efficiency, low temperature process, and other advantages. Copper is considered as an ideal candidate material for replacing the traditional silver electrode in terms of battery metal electrode materials because of low resistivity, abundant resources and significantly lower cost than silver. The copper grid line is prepared by adopting an electroplating process, so that the manufacturing cost of the solar cell can be effectively reduced, and a narrower electrode line width can be realized, thereby reducing the front shading loss and further improving the overall conversion efficiency of the cell. Currently, a metal electrode preparation process of a copper gate heterojunction solar cell generally includes a plurality of steps such as deposition of a copper seed layer, patterning, electroplating thickening, and etching back of the seed layer. The main function of the seed layer etching back process is to remove the residual copper seed layer in the area outside the electrode after the copper electrode electroplating is completed so as to form a metal electrode structure with good selectivity. However, in the actual production process, since the wet etching process has isotropic etching characteristics, the etching solution etches the copper seed layer in the vertical direction, and meanwhile, lateral erosion is often unavoidable, so that an obvious lateral erosion phenomenon (also called "undercut") is generated at the bottom of the copper electrode, and the lateral erosion problem easily causes defects such as pinholes, pits and the like on the surface of the copper electrode, so that the binding force between the copper electrode and the underlying battery substrate is weakened, the stability of the electrode structure is influenced, and adverse effects on the electrical performance and long-term reliability of the battery are also possible. In the prior art, aiming at the etching back process of a copper seed layer, an acid etching liquid system consisting of potassium hydrogen persulfate composite salt (KHSO 5·0.5KHSO4·0.5K2SO4) and concentrated sulfuric acid (H 2SO4) is commonly adopted in industry, and the etching liquid has good chemical stability in an acid environment, can effectively remove the copper seed layer, and is widely applied to related processes, and in practical application, the etching system still has the problem that the etching rate is not accurate enough, namely, when the etching rate is high, the side etching phenomenon of a copper electrode is often aggravated, and when the etching rate is reduced to inhibit the side etching, the residual copper seed layer is possibly removed incompletely, and the performance and the yield of a subsequent battery are influenced. Therefore, in the seed layer etching-back process of the copper gate heterojunction solar cell, how to effectively inhibit the lateral etching and bottom side etching of the copper electrode in the etching-back process while ensuring that the residual copper seed layer can be sufficiently and thoroughly removed, so as to reduce the electrode surface corrosion defect and improve the electrode structural integrity and the cell overall performance is still one of the key technical problems to be solved urgently in the current field. Disclosure of Invention The first technical problem to be solved by the invention is to provide a composite corrosion inhibitor etching solution to solve the problems of strong etching isotropy, serious side etching and easy copper electrode undercut and surface defect caused in the process of removing the residual copper seed layer of the existing acid etching system. In order to overcome the defects in the prior art, the invention provides a composite corrosion inhibitor etching solution, which comprises the following components: oxidizing agent is potassium hydrogen persulfate composite salt; Acid is concentrated sulfuric acid; The composite corrosion inhibitor consists of a first corrosion inhibitor and a second corrosion inhibitor, wherein the first corrosion inhibitor is a nitrogen-containing heterocyclic compound capable of forming a covered adsorption film on the surface of copper, and the second corrosion inhibitor is a nitrogen-containing heterocyclic compound capable of being preferentially adsorbed on high-activity sites on the surface of copper; solvent, deionized water. Compared with the prior art, the compo