Method and device for recycling tetramethylammonium hydroxide in developing waste liquid

Abstract

The invention discloses a method and device for recycling tetramethylammonium hydroxide in developing waste liquid. The device comprises a waste liquid collecting tank, a first filtering device, a nanofiltration device, a first adjusting tank, a second adjusting tank and a second filtering device which are sequentially connected through a material pipeline with a control valve; solid impurities in the developing waste liquid are removed through the first filtering device; a photoresist in the waste liquid is removed through the nanofiltration device, filtrate enters the first adjusting tank to be adjusted and collected, nanofiltration secondary waste liquid is collected and enters the second adjusting tank to precipitate the photoresist, then the photoresist is removed through filtering; the waste liquid enters the first adjusting tank to be collected; the solution in the first adjusting tank is adjusted and then enters an evaporation concentration device to be further concentrated; the solution enters a cation exchange resin column, so that metal ions are removed, and the solution enters an anion exchange resin column, the high-purity TMAH aqueous solution is obtained. The method is high in TMAH recovery rate, capable of realizing continuous production, energy-saving and environment-friendly in process and easy to popularize and use.

Description

technical field [0001] The invention relates to a method and device for recycling tetramethylammonium hydroxide in developing waste liquid, in particular to a recycling device for tetramethylammonium hydroxide solution used in electronic manufacturing industries such as liquid crystal displays and semiconductors. Background technique [0002] The photolithography process is an important part in the electronic manufacturing of liquid crystal displays, ICs and printed substrates. In the photolithography process, a positive or negative photoresist film is generally formed on a silicon wafer substrate, and then a mask is used to expose the coated photoresist film according to a prescribed pattern, and then a developer is used to expose the exposed photoresist film. The photoresist is cleaned, then etched, and finally the insoluble photoresist on the silicon substrate is treated with a stripping solution to meet the requirements for forming a specified pattern, and tetramethylamm...

AI Technical Summary

Problems solved by technology

In addition to TMAH, the waste liquid produced after development generally contains dissolved photoresist and various low-concentration metal ions, so it cannot be recycled directly.

At the same time, TMAH is a kind of nitrogen-containing organic strong alkaline substance, which is difficult to process through traditional water treatment technology, which causes a large amount of TMAH waste while increasing the treatment cost. CN101993380A provides a kind of TMAH recovery equipment and method through nanofiltration that can effectively To remove photoresist and some metal ions in wastewater, TMAH is concentrated by adsorption resin and the recovery of TMAH on the concentration side of nanofiltration is not considered. The overall recovery rate of TMAH is not high. The TMAH recovery and utilization device provided by CN105541641A uses calcium hydroxide precipitant. Incomplete conversion of tetramethylammonium hydroxide is difficult to meet the quality requirements of electronics manufacturing plants; CN108623052A provides a method for recovering TMAH in secondary waste liquid to fully recycle the secondary waste liquid of development, but the device involves electrolytic dialysis equipment and ordinary distillation Thickening device greatly increases the cost of electricity and steam energy consumption

Therefore, there is still room for improvement in the recycling and reuse of TMAH in the developing waste liquid. On the one hand, the recovery rate can be improved to reduce costs, and on the other hand, the cleanliness requirements of recycled products need to be further improved.

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