Photoresist waste liquid recycling device and process

Abstract

The application provides a photoresist waste liquid recycling device and process, by adding hydrochloric acid to the photoresist waste liquid in the acidification precipitation tank in the pretreatment module to adjust the pH value, the linear phenolic resin precipitation rate reaches more than 95%, and the linear phenolic resin can be used again to the production stage of the photoresist after centrifugal separation, a compound coagulant containing sulfide and polyaluminum chloride is added to the heavy metal capture tank in the pretreatment module, and the removal rate of heavy metal ions reaches 99.5%; then the photoresist fragments are separated by using an ultrafiltration device, and the diatomite modified by NaOH and polyetherimide is used for adsorption and decolorization, then two-stage vacuum distillation process is used to realize the recovery of high-purity solvents in the photoresist waste liquid, finally, the remaining residue is polymerized and cured by ultraviolet radiation, and the solid fuel with high heat value can also be prepared, so that the 'zero emission' and resource full recovery of the photoresist waste liquid are realized, and the treatment cost and environmental risk are significantly reduced.

Description

Technical Field

[0001] This invention relates to the field of waste liquid recycling and treatment technology, and in particular to a photoresist waste liquid recycling and treatment device and process. Background Technology

[0002] With the rapid development of semiconductor integrated circuit manufacturing technology, processes such as exposure, development, etching, and photoresist stripping are crucial production steps in chip manufacturing. These processes require the use of developing solutions to clean uncured photoresist, resulting in the generation and discharge of large amounts of photoresist waste liquid. This waste liquid contains heavy metal ions such as nickel and copper, as well as highly corrosive solvents like N-methylpyrrolidone. Direct discharge would cause severe pollution to water bodies and soil, leading to irreversible ecological damage. Furthermore, the organic pollutants in the waste liquid will diffuse and volatilize, with the resulting volatile organic compound (VOC) emissions typically reaching 50-100 ppm, far exceeding the current requirement of ≤5 ppm. This would exacerbate air pollution and seriously impact air quality and human health. Therefore, photoresist waste liquid generated during chip manufacturing needs to be recycled and treated.

[0003] Currently, the industry generally adopts two models for the treatment of photoresist waste liquid: one is to directly entrust the waste liquid to external professional organizations for disposal; the other is for companies to set up concentration devices and other processes in-plant for treatment. However, in reality, photoresist waste liquid still contains 30% to 50% high-value recyclable solvents, such as diethylene glycol monobutyl ether and monoethanolamine. Directly entrusting the disposal not only fails to recover these high-value solvents, but also causes huge waste of resources and economic losses. Furthermore, existing treatment processes are unable to completely separate or render harmless the highly corrosive N-methylpyrrolidone and heavy metal ions such as nickel and copper. Direct discharge of these substances poses a serious environmental pollution hazard and cannot fundamentally solve the environmental toxicity problem. In addition, traditional membrane filtration technology is easily clogged by the high molecular weight photoresist substances in the waste liquid, resulting in short equipment operating cycles and high maintenance costs. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a photoresist waste liquid recycling and treatment device and process to solve the problems of high-value recyclable solvents in photoresist waste liquid that cannot be directly recycled in the prior art, resulting in resource waste and economic losses, as well as the environmental pollution, short equipment operation cycle and high maintenance cost that existing treatment processes still face.

[0005] To achieve the above and other related objectives, the present invention provides a photoresist waste liquid recycling and treatment device, the recycling and treatment device comprising at least:

[0006] The liquid collection module is connected to the coating and developing machine via a first liquid inlet pipe to collect photoresist waste liquid. The first liquid inlet pipe is equipped with a first pump body and includes a first liquid collection tank and a second liquid collection tank connected in parallel. A first control valve is also provided between the first liquid inlet pipe and the first liquid collection tank, and a second control valve is also provided between the first liquid inlet pipe and the second liquid collection tank. An early warning device is provided in the first liquid collection tank and the second liquid collection tank. When the liquid level in the first liquid collection tank and the second liquid collection tank exceeds a preset safety value, the early warning device can trigger an alarm unit.

[0007] The pretreatment module includes an acidification precipitation tank and a heavy metal capture tank. The inlet of the acidification precipitation tank is connected to the collection module through a second inlet pipe. A second pump is installed on the second inlet pipe, and the second inlet pipe is connected to the first collection tank through a third pipe. A third control valve is installed on the third pipe, and the second collection tank is connected through a fourth pipe. A fourth control valve is installed on the fourth pipe. The outlet of the acidification precipitation tank is connected to the heavy metal capture tank through a second outlet pipe. A fourth pump is installed on the second outlet pipe.

[0008] The deep purification module is connected to the pretreatment module through the second liquid outlet pipeline. The deep purification module includes an adsorption tower and a multi-stage vacuum distillation device. The inlet end of the adsorption tower is connected to the heavy metal capture tank, and an ultrafiltration device and a fourth pump are also provided between the adsorption tower and the heavy metal capture tank. The inlet end of the multi-stage vacuum distillation device is connected to the adsorption tower, and the outlet end of the vacuum distillation device is connected to the photoresist supply end of the coating and developing machine.

[0009] The residue treatment module includes an ultraviolet radiation curing device. The inlet of the ultraviolet radiation curing device is connected to the residue outlet of the multi-stage vacuum distillation device, and the remaining photoresist residue is polymerized and cured by ultraviolet radiation to form a solid fuel. Optionally, the early warning device is a liquid level sensor, and the alarm unit is an audible and visual alarm or a remote monitoring terminal. The response time of the early warning device to exceeding the liquid level in the first and second collection tanks is less than 10 seconds.

[0010] Optionally, the first control valve, the second control valve, the third control valve, the fourth control valve, and the fifth control valve are all one-way valves; the conduction direction of the first control valve and the second control valve is from the coating and developing machine to the liquid collection module, the conduction direction of the third control valve and the fourth control valve is from the liquid collection module to the acidification precipitation tank, and the conduction direction of the fifth control valve is from the acidification precipitation tank to the heavy metal capture tank.

[0011] Optionally, the ultrafiltration device is equipped with a 50kDa ultrafiltration membrane to separate photoresist fragments from the photoresist waste liquid.

[0012] Optionally, the multi-stage vacuum distillation apparatus includes a first-stage vacuum distillation column and a second-stage vacuum distillation column connected in series, wherein the distillation temperature of the first-stage vacuum distillation column is 80°C and the pressure is 50 kPa, and the distillation temperature of the second-stage vacuum distillation column is 120°C and the pressure is 10 kPa.

[0013] This invention also provides a process for recycling and treating photoresist waste liquid, characterized in that the photoresist waste liquid is recycled and treated using a photoresist waste liquid recycling and treatment device, and the recycling and treatment process includes the following steps:

[0014] An acidic substance was added to the photoresist waste liquid to adjust its pH value to 2-4. The resulting precipitate was separated by centrifugation to obtain phenolic resin precipitate and primary filtrate in liquid phase.

[0015] The primary filtrate is pumped into the heavy metal capture tank, and a compound coagulant is added to the primary filtrate to generate heavy metal sulfide precipitates. The heavy metal ion precipitates are removed by solid-liquid separation to obtain the secondary filtrate in liquid phase.

[0016] The ultrafiltration device is used to ultrafilter the secondary filtrate to obtain permeate. The permeate is then passed into the adsorption tower loaded with adsorption material for adsorption, decolorization and removal of trace metal ions to obtain photoresist regeneration solution.

[0017] The photoresist regeneration solution is distilled and purified to obtain a high-purity solvent that is reused in the coating and developing machine. The remaining photoresist residue is then subjected to ultraviolet radiation polymerization and curing to form a solid fuel.

[0018] Optionally, the acidic substance includes one of sulfuric acid, hydrochloric acid, nitric acid, carbonic acid, or phosphoric acid, wherein the concentration of the hydrochloric acid is 5% to 10%.

[0019] Optionally, the compound coagulant includes a sulfide and polyaluminum chloride, wherein the sulfide is sodium sulfide, and the mass ratio of sodium sulfide to polyaluminum chloride is controlled at 0.5:1 to 1.5:1.

[0020] Optionally, the adsorbent material includes modified diatomaceous earth, which is prepared by: soaking and washing natural diatomaceous earth in sodium hydroxide solution, then performing surface modification treatment with polyetherimide ethanol solution, and finally drying and grinding.

[0021] Optionally, the distillation process includes a two-stage vacuum distillation process, comprising the following steps: the first stage vacuum distillation is carried out at a temperature of 80°C and a pressure of 50 kPa to remove low-boiling-point impurities; the second stage vacuum distillation is carried out at a temperature of 120°C and a pressure of 10 kPa to purify the photoresist components.

[0022] As described above, the photoresist waste liquid recycling and treatment device and process of the present invention have the following beneficial effects: by adding hydrochloric acid to the photoresist waste liquid in the acidification precipitation tank of the pretreatment module to adjust the pH value, the linear phenolic resin precipitation rate reaches more than 95%, and the linear phenolic resin can be reused in the photoresist production stage after centrifugal separation. A compound coagulant containing sulfide and polyaluminum chloride is added to the heavy metal capture tank of the pretreatment module to achieve a heavy metal ion removal rate of 99.5%. Then, the photoresist fragments are separated by ultrafiltration device, and adsorption and decolorization are carried out by diatomaceous earth modified with NaOH and polyetherimide. Subsequently, the high-purity solvent in the photoresist waste liquid is recovered through a two-stage vacuum distillation process. Finally, the remaining residue can be polymerized and solidified by ultraviolet radiation to produce high-calorific-value solid fuel, thereby achieving "zero discharge" and full resource recovery of photoresist waste liquid, significantly reducing treatment costs and environmental risks. Attached Figure Description

[0023] Figure 1 The diagram shown is a flow chart of a photoresist waste liquid recycling and treatment process according to the present invention.

[0024] Figure 2 The diagram shown is a structural schematic of a photoresist waste liquid recycling and treatment device according to the present invention.

[0025] Component designation explanation

[0026] 10. Coating and developing machine; 11. Liquid collection module; 111. First pipe; 112. Second pipe; 113. First control valve; 114. Second control valve; 115. First collection tank; 116. Second collection tank; 117. Third pipe; 118. Third control valve; 1110. Fourth pipe; 1111. Fourth control valve; 119. Early warning device; 12. Pretreatment module; 121. Acidification sedimentation tank; 122. Fifth control valve; 123. Fifth pipe; 124. Third pump body; 12 5. Heavy metal capture tank; 13. Deep purification module; 131. Ultrafiltration device; 132. Adsorption tower; 133. Vacuum distillation device; 134. Sixth pipeline; 135. Fifth pump body; 136. Sixth pump body; 137. Seventh pipeline; 14. Residue treatment module; 141. Recovery pipeline; 15. First inlet pipeline; 16. First pump body; 17. Second inlet pipeline; 18. Second pump body; 19. Fourth pump body; 20. Second outlet pipeline; 21. Third inlet pipeline; S1~S4, Steps. Detailed Implementation

[0027] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0028] It should be understood that the use of terms such as "first" and "second" to define the components is merely for the purpose of distinguishing the aforementioned components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0029] It should be noted that the illustrations provided in this embodiment are only intended to illustrate the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the shape, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0030] Example 1

[0031] In one embodiment of the present invention, a photoresist waste liquid recycling and treatment device is provided, which is externally connected to a coating and developing machine to realize the recycling and treatment of photoresist waste liquid after coating and developing. The recycling and treatment device includes four modules, namely a liquid collection module, a pretreatment module, a deep purification module, and a residue treatment module.

[0032] like Figure 2As shown, the liquid collection module 11 includes a first liquid inlet pipe 15, a first liquid collection tank 115, and a second liquid collection tank 116. One end of the first liquid inlet pipe 15 is connected to the photoresist waste liquid outlet of the coating and developing machine 10. A first pump body 16 is installed on the first liquid inlet pipe 15. The first liquid inlet pipe 15 is connected to both the first liquid collection tank 115 and the second liquid collection tank 116. The first liquid inlet pipe 15 and the first liquid collection tank 115 are connected by a first pipe 111, and a first control valve 113 is installed on the first pipe 111. The first liquid inlet pipe 15 and the second liquid collection tank 116 are connected by a second pipe. The first and second control valves 113 and 114 are connected and are provided with a second control valve 114. The first control valve 113 and the second control valve 114 are one-way valves and are directed from the coating and developing machine to the liquid collection module. The first pump body 16 and the first control valve 113 control the connection between the first liquid inlet pipe 15 and the first liquid collection tank 115 to realize the transfer of photoresist waste liquid to the first liquid collection tank 115. The first pump body 16 and the second control valve 114 control the connection between the first liquid inlet pipe 15 and the second liquid collection tank 116 to realize the transfer of photoresist waste liquid to the second liquid collection tank 116.

[0033] like Figure 2 As shown, both the first collection tank 115 and the second collection tank 116 are equipped with an early warning device 119. The type of the early warning device 119 is a liquid level sensor. Under normal circumstances, the height of the liquid level sensor will not exceed the preset safety value of the first collection tank 115 and the second collection tank 116. The preset safety value can be 80%, 85%, or 90% of the capacity of the first collection tank 115 and the second collection tank 116. In addition, in this embodiment, the first collection tank 115 is the main collection tank and the second collection tank 116 is the secondary collection tank. When the liquid level of the photoresist waste liquid in the main collection tank exceeds the preset safety value, it can automatically switch to the secondary collection tank.

[0034] In some embodiments, the alarm unit is an audible and visual alarm or a remote monitoring terminal prompt, and the liquid level sensor is coupled to the alarm unit. When the liquid level of the first liquid collection tank 115 or the second liquid collection tank 116 exceeds a preset safety threshold, the liquid level sensor can trigger the audible and visual alarm to issue an alarm or trigger the remote monitoring terminal prompt to remind the monitoring staff. The response time when the liquid level exceeds the threshold should be less than 10 seconds, for example, it can be 5 seconds, 6 seconds, 7 seconds, 8 seconds or 9 seconds, so that technicians can quickly handle emergencies.

[0035] like Figure 2As shown, the liquid collection module 11 is connected to the pretreatment module 12 via a second inlet pipe 17. A second pump body 18 is installed on the second inlet pipe 17. The pretreatment module 12 includes an acidification sedimentation tank 121. Specifically, the inlet of the acidification sedimentation tank 121 is connected to the first liquid collection tank 115 and the second liquid collection tank 116 via the second inlet pipe 17. The second inlet pipe 17 and the first liquid collection tank 115 are connected via a third pipe 117, and a third control valve 117 is installed on the third pipe 117. The second inlet pipe 17 and the second liquid collection tank 116 are connected via a fourth pipe 1110, and a fourth control valve 118 is installed on the fourth pipe 1110. The third control valve 117 and the fourth control valve 118 are unidirectional. The valve, with its conduction direction from the liquid collection module to the acidification precipitation tank, controls the conduction state between the first liquid collection tank 115 and the acidification precipitation tank 121 through the second pump body 18 and the third control valve 117, realizing the transfer of photoresist waste liquid to the acidification precipitation tank 121. The second liquid collection tank 116 and the acidification precipitation tank 121 are controlled by the second pump body 18 and the fourth control valve 118, realizing the transfer of photoresist waste liquid to the acidification precipitation tank 121. During the treatment of photoresist waste liquid, acidic substances can be added to the acidification precipitation tank 121 to adjust the pH value, thereby causing the phenolic resin in the photoresist waste liquid in the acidification precipitation tank 121 to form phenolic resin precipitate and be precipitated. The remaining waste liquid forms the liquid phase primary filtrate to continue the subsequent process.

[0036] like Figure 2 As shown, the pretreatment module 12 further includes a heavy metal capture tank 125, which is connected to the outlet of the acidification precipitation tank 121 via a fifth pipe 123. A fifth control valve 122 and a third pump body 124 are also installed on the fifth pipe 123. The fifth control valve 122 is a one-way valve, and its conduction direction is from the acidification precipitation tank to the heavy metal capture tank. The third pump body 124 and the fifth control valve 122 control the flow of the primary filtrate formed after acidification precipitation to the heavy metal capture tank 125. By adding a compound coagulant to the heavy metal capture tank 125, the heavy metal ions in the primary filtrate of the liquid phase are precipitated as heavy metal sulfides. The removal of heavy metal ions in the primary filtrate of the liquid phase can be achieved through solid-liquid separation process, and finally, a secondary filtrate of the liquid phase is obtained.

[0037] like Figure 2As shown, the deep purification module 13 is connected to the pretreatment module 12 through the second liquid outlet pipe 20. A fourth pump body 19 is provided on the second liquid outlet pipe 20. The deep purification module 13 includes an adsorption tower 132 and a multi-stage vacuum distillation device 133. Specifically, an ultrafiltration device 131 is also provided between the liquid inlet end of the adsorption tower 132 and the pretreatment module 12. The ultrafiltration device 131 uses a 50kDa ultrafiltration membrane to separate photoresist fragments in the secondary filtrate of the liquid phase. After separation, a permeate is obtained. The liquid inlet end of the adsorption tower 132 is connected to the ultrafiltration device 131 through a sixth pipe 134. A fifth pump body 135 is provided on the sixth pipe 134. The fifth pump body 135 controls the permeate to enter the adsorption tower 132. The adsorption tower 132 is loaded with adsorbent material. The adsorbent material can further adsorb and decolorize the permeate and remove trace metal ions to obtain a photoresist regeneration solution.

[0038] like Figure 2 As shown, the multi-stage vacuum distillation device 133 is connected to the outlet of the adsorption tower 132 via a seventh pipe 137, and a sixth pump 136 is installed on the seventh pipe 137. The sixth pump 136 controls the entry of the photoresist regeneration solution into the multi-stage vacuum distillation device 133. The multi-stage vacuum distillation device 133 includes a first-stage vacuum distillation tower and a second-stage vacuum distillation tower, which are connected in series. The distillation temperature of the first-stage vacuum distillation tower is set to 80°C and the pressure to 50 kPa, while the distillation temperature of the second-stage vacuum distillation tower is set to 120°C and the pressure to 10 kPa. After the photoresist regeneration solution undergoes two stages of vacuum distillation in the multi-stage vacuum distillation device 133, regenerated photoresist that can be reused is obtained. The outlet of the vacuum distillation device 133 is connected to the photoresist supply end of the coating and developing machine 10 via a recovery pipe 141, so that the regenerated photoresist can be directly applied to the coating and developing machine 10.

[0039] like Figure 2 As shown, the residue treatment module 14 includes an ultraviolet radiation curing device. The inlet of the ultraviolet radiation curing device is connected to the residue outlet of the multi-stage vacuum distillation device 133 through a third liquid inlet pipe 21. The ultraviolet radiation curing device can perform ultraviolet radiation polymerization curing on the distillation residue, and finally form a solid fuel with a calorific value of 18 MJ / kg.

[0040] Example 2

[0041] In another embodiment of the present invention, a photoresist waste liquid recycling process is also provided. The recycling process is based on the recycling device described in the above embodiment, and the photoresist waste liquid recycling process includes the following steps:

[0042] S1: Add an acidic substance to the photoresist waste liquid to adjust its pH value to 2-4, and centrifuge the generated precipitate to obtain phenolic resin precipitate and liquid phase primary filtrate.

[0043] S2: The primary filtrate is pumped into the heavy metal capture tank 125, and a compound coagulant is added to the primary filtrate to generate heavy metal sulfide precipitates. The heavy metal ion precipitates are removed by solid-liquid separation to obtain the secondary filtrate in liquid phase.

[0044] S3: Use the ultrafiltration device 131 to ultrafilter the secondary filtrate to obtain permeate, and pass the permeate into the adsorption tower 132 loaded with adsorption material for adsorption, decolorization and removal of trace metal ions to obtain photoresist regeneration solution.

[0045] S4: The photoresist regeneration solution is distilled and purified to obtain a high-purity solvent that is reused in the coating and developing machine 10. The remaining photoresist residue is then subjected to ultraviolet radiation polymerization and curing to form a solid fuel.

[0046] Specifically, a recycling processing apparatus as described in Embodiment 1 is provided, such as... Figure 2 As shown, in step S1, the first inlet pipe 15 and the first pump body 16 are opened, and the first control valve 113 is opened to allow the photoresist waste liquid after use by the coating and developing machine 10 to flow to the first collection tank 115 in the collection module 11. Then, the third control valve 117 and the second pump body 18 are opened in sequence to make the second inlet pipe 17 open, so that the photoresist waste liquid flows to the acidification precipitation tank 121. An acidic substance is added to the photoresist waste liquid in the acidification precipitation tank 121 to adjust the pH value of the photoresist waste liquid.

[0047] In some embodiments, the acidic substance includes one of sulfuric acid, hydrochloric acid, nitric acid, carbonic acid, or phosphoric acid, and when hydrochloric acid is selected as the acidic substance, the concentration of hydrochloric acid is 5% to 10%.

[0048] Specifically, in this embodiment, the acidic substance is selected as 5% hydrochloric acid. By adding hydrochloric acid, the pH value of the photoresist waste liquid is adjusted to 2-4. After thorough stirring and reaction for a period of time, under acidic conditions, the phenolic resin in the photoresist waste liquid will react to form phenolic resin precipitate. The phenolic resin precipitate is centrifuged to separate it, and finally, a primary filtrate that can be liquid-phase and linear phenolic resin that can be recycled are obtained, with a linear phenolic resin precipitation rate of over 95%.

[0049] In step S2, the third pump body 124 and the fifth control valve 122 are opened to open the fifth pipeline 123, thereby pumping the primary filtrate of the liquid phase into the heavy metal capture tank 125, and adding a compound coagulant to the primary filtrate in the heavy metal capture tank 125. The compound coagulant includes sulfide and polyaluminum chloride, wherein the sulfide is sodium sulfide, and the mass ratio of sodium sulfide to polyaluminum chloride is controlled at 0.5:1 to 1.5:1, for example, the mass ratio of sodium sulfide to polyaluminum chloride is 0.5:1, 1:1 or 1.5:1. Specifically, sodium sulfide acts as a precipitant, dissociating into sulfide ions in water. These sulfide ions react with various heavy metal ions (such as copper, lead, zinc, cadmium, and mercury) in the primary filtrate to form metal sulfide precipitates with extremely low solubility and are very difficult to dissolve in water. The resulting metal sulfide precipitate particles are usually very small and difficult to settle naturally. At this point, polyaluminum chloride "captures" and aggregates the metal sulfide precipitate particles through charge neutralization, adsorption bridging, and other processes, forming larger and denser flocs. Finally, a liquid phase secondary filtrate is obtained through a solid-liquid separation process, thereby achieving a 99.5% removal rate of heavy metal ions from the primary filtrate.

[0050] In step S3, the fourth pump body 19 is opened to connect the second outlet pipe 20, thereby pumping the secondary filtrate of the liquid phase into the ultrafiltration device 131. The ultrafiltration device 131 is equipped with a 50kDa ultrafiltration membrane. The presence of the ultrafiltration membrane can trap photoresist fragments in the secondary filtrate, thereby obtaining permeate. Then, the fifth pump body 135 is further opened to connect the sixth pipe 134, and the permeate is pumped into the adsorption tower 132 loaded with adsorption material. The adsorption material can adsorb and decolorize the permeate and remove trace metal ions, thereby obtaining photoresist regeneration solution.

[0051] As an example, the adsorbent material includes modified diatomaceous earth, which is prepared by: soaking and washing natural diatomaceous earth in sodium hydroxide solution, then performing surface modification treatment with polyetherimide ethanol solution, and finally drying and grinding.

[0052] Specifically, in this embodiment, the adsorbent material is modified diatomaceous earth. The processing procedure for the modified diatomaceous earth is as follows: First, diatomaceous earth raw material with a SiO2 content ≥ 85% is selected and pulverized to 300 mesh. A 10% sodium hydroxide aqueous solution is prepared. The diatomaceous earth raw material is added to the sodium hydroxide aqueous solution at a solid-liquid ratio of 1:10 and stirred evenly. The mixture is stirred and reacted at 100°C for 6 hours. It is then repeatedly washed with deionized water until the pH value equals 8. Finally, it is dried at 105°C and calcined at 500°C for 2 hours. After 4 hours, the treated diatomaceous earth was added to N-methylpyrrolidone and ultrasonically dispersed for 30 minutes to obtain a diatomaceous earth dispersion. Polyetherimide was added to N-methylpyrrolidone and stirred at 90°C until completely dissolved to obtain a mixed solution. The diatomaceous earth dispersion was slowly added to the mixed solution and stirred at 90°C for 4 hours. After cooling to room temperature, ethanol was added to precipitate the product. The product was washed three times with ethanol and then dried at 105°C. Finally, it was heat-treated at 200°C for 3 hours and ground to obtain modified diatomaceous earth.

[0053] In step S4, the sixth pump body 136 is turned on, thereby pumping the photoresist regeneration solution into the multi-stage vacuum distillation apparatus 133. The multi-stage vacuum distillation apparatus 133 includes a first-stage vacuum distillation column and a second-stage vacuum distillation column connected in series. The first-stage vacuum distillation column has a distillation temperature of 80°C and a pressure of 50 kPa, used to remove low-boiling-point impurities. The second-stage vacuum distillation column has a distillation temperature of 120°C and a pressure of 10 kPa, used to purify the photoresist components to obtain a high-purity solvent. The purified high-purity solvent can also be recycled back to the coating and developing machine 10 via the recovery pipe 141.

[0054] Furthermore, the remaining photoresist residue is discharged into the residue treatment module 14, where the distillation residue is treated by the ultraviolet radiation curing device. Under ultraviolet light radiation, the distillation residue can polymerize and solidify to form a solid fuel with a calorific value of 18 MJ / kg.

[0055] In summary, this invention provides a photoresist wastewater recycling and treatment device and process. By adding hydrochloric acid to the photoresist wastewater in the acidification precipitation tank of the pretreatment module to adjust the pH value, the precipitation rate of linear phenolic resin reaches over 95%. The linear phenolic resin, after centrifugation, can be reused in the photoresist production stage. A compound coagulant containing sulfides and polyaluminum chloride is added to the heavy metal capture tank of the pretreatment module to achieve a heavy metal ion removal rate of 99.5%. Then, an ultrafiltration device is used to separate photoresist fragments, and diatomaceous earth modified with NaOH and polyetherimide is used for adsorption and decolorization. Subsequently, a two-stage vacuum distillation process is used to recover high-purity solvents from the photoresist wastewater. Finally, the remaining residue is polymerized and solidified by ultraviolet radiation to produce high-calorific-value solid fuel, thereby achieving "zero discharge" and full resource recovery of photoresist wastewater, significantly reducing treatment costs and environmental risks. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and has high industrial application value.

[0056] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A photoresist waste liquid recycling and treatment device, characterized in that, The recycling and processing device includes at least: The liquid collection module is connected to the coating and developing machine via a first liquid inlet pipe to collect photoresist waste liquid. The first liquid inlet pipe is equipped with a first pump body and includes a first liquid collection tank and a second liquid collection tank connected in parallel. A first control valve is also provided between the first liquid inlet pipe and the first liquid collection tank, and a second control valve is also provided between the first liquid inlet pipe and the second liquid collection tank. An early warning device is provided in the first liquid collection tank and the second liquid collection tank. When the liquid level in the first liquid collection tank and the second liquid collection tank exceeds a preset safety value, the early warning device can trigger an alarm unit. The pretreatment module includes an acidification precipitation tank and a heavy metal capture tank. The inlet of the acidification precipitation tank is connected to the collection module through a second inlet pipe. A second pump is installed on the second inlet pipe, and the second inlet pipe is connected to the first collection tank through a third pipe. A third control valve is installed on the third pipe, and the second collection tank is connected through a fourth pipe. A fourth control valve is installed on the fourth pipe. The outlet of the acidification precipitation tank is connected to the heavy metal capture tank through a second outlet pipe. A fourth pump is installed on the second outlet pipe. The deep purification module is connected to the pretreatment module through the second liquid outlet pipeline. The deep purification module includes an adsorption tower and a multi-stage vacuum distillation device. The inlet end of the adsorption tower is connected to the heavy metal capture tank, and an ultrafiltration device is also provided between the adsorption tower and the heavy metal capture tank. The inlet end of the multi-stage vacuum distillation device is connected to the adsorption tower, and the outlet end of the vacuum distillation device is connected to the photoresist supply end of the coating and developing machine. The residue treatment module includes an ultraviolet radiation curing device. The inlet of the ultraviolet radiation curing device is connected to the residue outlet of the multi-stage vacuum distillation device, and the remaining photoresist residue is polymerized and cured by ultraviolet radiation to form solid fuel.

2. The photoresist waste liquid recycling and treatment device according to claim 1, characterized in that: The type of early warning device is a liquid level sensor, and the alarm unit is an audible and visual alarm or a remote monitoring terminal prompt. The response time of the early warning device to the liquid level exceeding the limit in the first and second liquid collection tanks is less than 10 seconds.

3. The photoresist waste liquid recycling and treatment device according to claim 1, characterized in that: The first control valve, the second control valve, the third control valve, the fourth control valve, and the fifth control valve are all one-way valves; the first control valve and the second control valve are directed from the coating and developing machine to the liquid collection module, the third control valve and the fourth control valve are directed from the liquid collection module to the acidification precipitation tank, and the fifth control valve is directed from the acidification precipitation tank to the heavy metal capture tank.

4. The photoresist waste liquid recycling and treatment device according to claim 1, characterized in that: The ultrafiltration device is equipped with a 50kDa ultrafiltration membrane to separate photoresist fragments from the photoresist waste liquid.

5. The photoresist waste liquid recycling and treatment device according to claim 1, characterized in that: The multi-stage vacuum distillation apparatus includes a first-stage vacuum distillation column and a second-stage vacuum distillation column connected in series. The first-stage vacuum distillation column has a distillation temperature of 80°C and a pressure of 50 kPa, while the second-stage vacuum distillation column has a distillation temperature of 120°C and a pressure of 10 kPa.

6. A process for recycling and treating photoresist waste liquid, characterized in that, The photoresist waste liquid is recycled and treated using the photoresist waste liquid recycling and treatment device according to any one of claims 1 to 5, wherein the recycling and treatment process includes the following steps: An acidic substance was added to the photoresist waste liquid to adjust its pH value to 2-4. The resulting precipitate was separated by centrifugation to obtain phenolic resin precipitate and primary filtrate in liquid phase. The primary filtrate is pumped into the heavy metal capture tank, and a compound coagulant is added to the primary filtrate to generate heavy metal sulfide precipitates. The heavy metal ion precipitates are removed by solid-liquid separation to obtain the secondary filtrate in liquid phase. The ultrafiltration device is used to ultrafilter the secondary filtrate to obtain permeate. The permeate is then passed into the adsorption tower loaded with adsorption material for adsorption, decolorization and removal of trace metal ions to obtain photoresist regeneration solution. The photoresist regeneration solution is distilled and purified to obtain a high-purity solvent that is reused in the coating and developing machine. The remaining photoresist residue is then subjected to ultraviolet radiation polymerization and curing to form a solid fuel.

7. The photoresist waste liquid recycling process according to claim 6, characterized in that: The acidic substance includes one of sulfuric acid, hydrochloric acid, nitric acid, carbonic acid, or phosphoric acid, wherein the concentration of the hydrochloric acid is 5% to 10%.

8. The photoresist waste liquid recycling process according to claim 6, characterized in that: The compound coagulant includes a sulfide and polyaluminum chloride, wherein the sulfide is sodium sulfide, and the mass ratio of sodium sulfide to polyaluminum chloride is controlled at 0.5:1 to 1.5:

1.

9. The photoresist waste liquid recycling process according to claim 6, characterized in that: The adsorbent material includes modified diatomaceous earth, and its preparation steps are as follows: natural diatomaceous earth is soaked and washed in sodium hydroxide solution in sequence, then surface modified with polyetherimide ethanol solution, and finally dried and ground.

10. The photoresist waste liquid recycling process according to claim 6, characterized in that: The distillation process includes a two-stage vacuum distillation process, comprising the following steps: the first stage vacuum distillation is carried out at a temperature of 80°C and a pressure of 50 kPa to remove low-boiling-point impurities; the second stage vacuum distillation is carried out at a temperature of 120°C and a pressure of 10 kPa to purify the photoresist components.

Images