Production method of electronic-grade sulphuric acid

Abstract

The invention discloses a production method of electronic-grade sulphuric acid. The production method comprises the following steps in sequence: industrial-grade sulfur trioxide raw materials are provided and placed into a raw material storage tank; the sulfur trioxide raw materials are conveyed into an evaporator tank; the evaporator tank is heated; sulfur trioxide steam generated by heating enters into an absorption tower through a filter; the sulfur trioxide steam is absorbed by electronic-grade ultrapure water in the absorption tower, the concentration of absorption liquid is controlled, and the absorbed solution enters into a degassing tower after cooled by a cooler; air stripping is performed on a sulfuric acid solution by the degassing tower through compressed air; the sulfuric acid solution enters into a finished product storage tank after cooled; finally, the final electronic-grade sulphuric acid applied to the integrated circuit industry is obtained after ultrafiltration to remove particles. The operating temperature of the technology, compared with a conventional technology, is lower than 120 DEG C. Therefore, the technology is safer than a high-temperature distillation technology which takes industrial-grade sulfuric acid as raw material, and in addition, compared with adopting equipment made of quartz glass, non-pollution to electronic-grade sulphuric acid products is guaranteed from equipment material.

Description

Technical field

[0001] The invention relates to a method for producing sulfuric acid, in particular to a method for producing electronic grade sulfuric acid required for the production of large-scale integrated circuits. Background technique

[0002] Sulfuric acid, chemical formula is H 2 SO 4 , With a relative molecular mass of 98.08, is a colorless, odorless, oily liquid, a strong acid with a high boiling point and difficult to volatile, easily soluble in water, and miscible with water in any ratio. Sulfuric acid is one of the important products in the basic chemical industry. It is not only used as a raw material for many chemical products, but also widely used in other sectors of the national economy.

[0003] Electronic grade sulfuric acid is currently widely used in integrated circuit manufacturing processes for resist stripping. The most commonly used sulfuric acid has a concentration of about 96%. Organic pollutants remaining on the substrate and related equipment will ha...

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