Recycling process of waste high boiling point photoresist stripper with improved recycle yield rate

Abstract

The present invention relates to a high boiling point waste photoresist stripper solution recycling method having an improved recycle yield rate. A main objective of the present invention is to provide a high boiling point waste photoresist stripper solution recycling method which can effectively resolve a problem of a bad odor caused by an alkaline by-product in a high boiling point residue during a second recycling process where the high boiling point residue discharged during a first recycling process is recycled for a second time to additionally collect a high boiling point stripper solvent during a waste stripper solution recycling process, and improve a recycle yield rate of the waste stripper solution recycling process compared to a conventional method. To achieve the objective, the high boiling point waste photoresist stripper solution recycling method having an improved recycle yield rate comprises: a neutralization process of neutralizing a high boiling point residue containing a high boiling point impurity removed and discharged during a first recycling process in a neutralization reaction tank, and solidifying the high boiling point impurity containing an alkaline by-product in the high boiling point residue; a solidified material removing process of removing a solidified material from the high boiling point residue transported from the neutralization reaction tank in a solidified material removal device; a moisture removing process of heating the high boiling point residue from which the solidified material is removed in a distillation device to remove moisture; and a fourth distillation process of heating the high boiling point residue from which the moisture is removed by the moisture removing process to additionally collect a high boiling point stripper solvent from the high boiling point residue.

Description

technical field [0001] The present invention relates to a method for regenerating photoresist high-boiling point stripping waste liquid, more specifically, to the following method for regenerating photoresist high-boiling point stripping waste liquid, which can effectively solve the problem of When the high-boiling point residue discharged in the primary regeneration process is subjected to secondary regeneration treatment and the high-boiling point stripping solvent is further recovered, malodor is generated in the secondary regeneration process due to alkaline by-products in the high-boiling point residue The problem is that compared with the prior art, the regeneration yield of the stripping waste liquid regeneration process can be further improved. Background technique [0002] In recent years, as the demand for photosensitizers that are at the heart of fine circuit patterns such as semiconductor wafers and circuit boards, and expensive stripping liquids for diluting and...

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Problems solved by technology

[0025] The existing patent proposes an optimal control method, which regulates the minimum water level of the waste liquid in the reboiler, so that the light can be delayed to the greatest extent during the 4th distillation of the 2nd regeneration process (Additional stripperrecycling). It can cause the precipitation of resist resin and maximize the regeneration yield of HEP. However, in the secondary regeneration process, the composite process operation must be repeated multiple times, so the regeneration process must be maintained at high temperature for a long time. There are several unavoidable process problems that may arise, and improvement is necessary

[0026] In particular, it is necessary to solve problems such as lowered productivity, troublesome processes caused by complex operations, decreased transparency of regenerated solvents (deterioration of APHA value, thermal discoloration), and increased thermal decomposition of HEP.

[0027] In addition, when existing patent reclaims HEP (1-piperazine ethanol) from photoresist high boiling point stripping waste liquid, by the aprotic solvent (NMP (N-methylpyrrolidone) that occurs in 1 removal process ), MMF (N-methylformamide)) thermal decomposition by-products and by-products generated by the thermal decomposition of HEP in the primary regeneration process will be exposed to high temperature (120 ~ 160°C), then it will be cooled during the process of being transported to the 4th distillation unit D-4, and then it will be continuously exposed to high temperature (120~160°C) again in the next 2 regeneration steps, therefore, by The interaction with the concentrated photoresist resin and photosensitizer generates highly volatile and foul-smelling oil mist, which causes inconvenience to process maintenance and management and local residents. There is also a problem of bad smell that occurs in the regeneration process Problems such as difficulty in the disposal of waste (the entrusted waste treatment company is unwilling to accept, etc.)

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