Selective ITO (tin indium oxide) etching solution

Abstract

The invention provides a selective ITO (tin indium oxide) etching solution. The etching solution is used for etching crystal and non-crystal ITO film layers, and is especially applicable to an ITO film of which the lower layer is a film substrate of organic polymers such as PET and the like and the upper layer is a monolayer or multilayer covering film consisting of copper or high-molecular compounds. The selective ITO etching solution is composed of the following components in percentage by weight: 15-25% of hydrochloric acid, 1-10% of acetic acid, 0.5-5% of a copper corrosion inhibitor, 5-500 ppm of a surfactant, and the balance of deionized water, wherein the copper corrosion inhibitor is at least one of a long-chain water-soluble amine compound and a triazole compound; the surfactant is a non-ionic surfactant. The etching solution is high in etching speed, effective, stable, free of residues and uniform in etching, and can be used for etching ITO completely, the edge of an ITO line is clear and has no lateral erosion, and the etching solution has no corrosion effect on copper layers.

Description

technical field [0001] The invention relates to an etching solution suitable for transparent conductive films in touch screen panels, in particular to a selective indium tin oxide (ITO) etching solution, especially suitable for the lower layer of the ITO film is polyethylene terephthalate ( PET) and other organic polymer film substrates, and the upper layer of the ITO film is a single-layer or multi-layer covering film composed of copper or polymer compounds, which belongs to the field of fine chemicals. Background technique [0002] Indium tin oxide (ITO) conductive film has many excellent physical properties such as low resistivity, high visible light transmittance, high infrared reflection, good adhesion to the substrate, anti-scratch, and good chemical stability, etc. It is easy to prepare and form electrode patterns, and has been widely used as transparent electrodes on LCD, PDP, FED, OLED / PLED and other flat panel displays. [0003] In order to prepare the required el...

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Problems solved by technology

Among them, although the etching rate of the aqua regia system is very fast, it has a strong corrosion effect on the copper film on the upper layer of ITO, and is easy to cause damage to the ITO below the copper layer; while the oxalic acid system has a very slow etching rate on the crystalline ITO. It is mainly used for the etching of amorphous ITO, and it is easy to produce precipitation during use, and the application range is small and the effect is not good; although the etching rate of the ferric chloride system is also very fast, it also faces the problems encountered by the aqua regia system. The problem is that it will also have a strong oxidation effect on the metal, which will cause serious corrosion of the copper film on the upper layer of ITO; while the hydroiodic acid system has good etching performance, but its stability is poor, and it is easy to dissociate iodine, and because of its high price and high toxicity, its App is restricted

[0005] In addition, the aqueous solution system composed of hydrochloric acid and acetic acid is favored by operators due to its advantages such as stable rate and no residue formation when used as an ITO etching solution, but this system still has great corrosion on the copper layer and is prone to side corrosion. Problems such as incomplete etching

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