CN213004696U

CN213004696U - Grinding fluid regeneration and recovery system

Info

Publication number: CN213004696U
Application number: CN202021228850.4U
Authority: CN
Inventors: 郑圣弘; 宋凯; 吴思韵
Original assignee: Shenzhen Rongke Technology Co ltd
Current assignee: Jiangsu Rongke Equipment Technology Co ltd
Priority date: 2020-06-29
Filing date: 2020-06-29
Publication date: 2021-04-20
Anticipated expiration: 2030-06-29

Abstract

The utility model relates to a chemical mechanical polishing technical field, concretely relates to lapping liquid regeneration recovery system, store bucket, membrane filter equipment, infiltration bucket groove, turbidimeter and controller including waste liquid collecting vessel, circulation, the waste liquid is collected and is stored the bucket intercommunication with the circulation, circulation storage bucket constitutes concentrated return circuit with membrane filter equipment, membrane filter equipment's infiltration end fixedly connected with circulating line, last infiltration bucket groove and the anti-scavenging pump of being provided with of circulating line, the turbidimeter sets up in the circulation storage bucket, still be provided with output pipeline on the circulation storage bucket, the last output pump that still is provided with of output pipeline, turbidimeter, output pump all with the controller electricity is connected. The recovery process of the grinding fluid regeneration recovery system is simple and reliable, the grinding fluid can be recycled, the processing cost in the CMP process is effectively reduced, waste discharge is optimized, and the burden of environmental protection is reduced.

Description

Grinding fluid regeneration and recovery system

Technical Field

The utility model relates to a chemical mechanical polishing technical field especially relates to lapping liquid regeneration recovery system.

Background

Chemical mechanical polishing is by far the only surface finishing technique that can provide global planarization and has been widely used for planarization of surfaces of integrated circuit chips, computer rigid disks, micro-mechanical systems, and the like. As the size of the machined workpiece is getting larger and the machining precision is gradually improved, chemical mechanical polishing, as a technique suitable for this requirement, has now developed into an inevitable choice in the polishing process.

With the rapid development of communication networks and the like, the demand for Integrated Circuits (ICs) is increasing, and the development of ICs is continuously moving toward high speed, high integration, high density and high performance. On one hand, in chip manufacturing, in order to reduce production cost, the size of a silicon wafer is gradually increased; on the other hand, in order to improve the integration of ICs, the scribe line width is continuously reduced. The requirements for planarization of silicon wafer surfaces are becoming more stringent, and the requirements for material removal rate, surface roughness, and surface/subsurface non-damage during polishing are increasing, and Chemical Mechanical Polishing (CMP) is widely used in IC manufacturing as a currently recognized global planarization technology. In the conventional CMP, the polishing solution as a consumable material accounts for about 40% of the total cost of the CMP process, but the utilization rate thereof can only reach 20%, and therefore, the cost of the CMP process depends on the cost of consumables, especially the cost of the polishing solution. Therefore, excessive use of the polishing solution not only causes high manufacturing cost of the IC, but also generates a large amount of waste polishing solution to pollute the surrounding environment.

80% of the polishing solution is not degraded in the CMP process, and in the polishing process, because a large amount of deionized water is used for cleaning the wafer, the abrasive concentration of the polishing solution is reduced, and the same polishing quality cannot be obtained by using the polishing solution again for polishing. Meanwhile, the large amount of grinding waste liquid generated during the chemical mechanical polishing process means a considerable cost for wastewater treatment. Therefore, the used grinding fluid is recycled and has great practical value.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problem, an object of the utility model is to provide a lapping liquid regeneration recovery system, its recovery process is simple reliably can realize the recycle of lapping liquid, effectively reduces the processing cost of CMP process, and optimizes the wasting discharge, reduces the burden of environmental protection.

In order to achieve the technical effects, the utility model adopts the following technical scheme:

the utility model provides a lapping liquid regeneration recovery system, includes waste liquid collecting vessel, circulation storage bucket, membrane filter equipment, infiltration bucket groove, turbidimeter and controller, the waste liquid collecting vessel through first pipeline with the circulation storage bucket intake end intercommunication, the backward flow end of circulation storage bucket passes through second pipeline and membrane filter equipment's intake end intercommunication, membrane filter equipment's backward flow end through third pipeline with the return water end intercommunication of circulation storage bucket, membrane filter equipment's infiltration end fixedly connected with circulating line, last infiltration bucket groove and the anti-cleaning pump of being provided with of circulating line, be provided with agitating unit in the circulation storage bucket, the turbidimeter sets up in the circulation storage bucket, still be provided with output pipeline on the circulation storage bucket, still be provided with the output pump on the output pipeline, anti-cleaning pump, turbidimeter, The output pumps are all electrically connected with the controller.

Further, a pressure pump is arranged on the second conveying pipeline, a pressure sensor is arranged in the second conveying pipeline, and the pressure pump and the pressure sensor are electrically connected with the controller.

Furthermore, the grinding fluid regeneration and recovery system also comprises a plurality of additive barrel tanks, the additive barrel tanks are respectively communicated with the circulating storage barrel through different infusion pipelines, and the infusion pipelines are respectively provided with an additive pump which is electrically connected with the controller.

Further, a first filtering device is arranged on the infusion pipeline.

Further, a coarse filtering device is arranged in front of the first filtering device.

Further, the filtration precision of rough filtration device is 50um-150 um.

Further, a second filtering device is arranged on the output pipeline.

Further, the first filtering device and the second filtering device are both filter element type filters.

Further, the waste liquid collecting barrel, the circulating storage barrel and the additive barrel groove are of an airtight structure, and the waste liquid collecting barrel, the circulating storage barrel and the additive barrel groove are communicated with the nitrogen conveying pipeline.

Further, the controller is a PLC controller.

Compared with the prior art, the beneficial effects of the utility model reside in that: the utility model provides a pair of lapping liquid regeneration recovery system is through collecting and the edulcoration to the lapping waste liquid, can concentrate and retrieve the abrasive material in the lapping waste liquid effectively, and carry out regeneration treatment recycling of being convenient for to the lapping liquid of retrieving through adding the additive, can carry out recycle to the lapping liquid effectively on the one hand, reduce the cost of grinding, and simultaneously, still help reducing the production of the waste liquid among the chemical mechanical polishing process, reduce the post processing cost of waste liquid, economic benefits and the environmental benefit who is showing have.

Drawings

Fig. 1 is a schematic view of an overall structure of a polishing slurry recycling system according to an embodiment of the present invention;

the reference signs are: 10-a waste liquid collecting barrel, 20-a first conveying pipeline, 21-a conveying pump, 22-a rough filtering device, 23-a first filtering device, 30-a circulating storage barrel, 40 a-a second conveying pipeline, 40 b-a third conveying pipeline, 401-a pressure pump, 402-a pressure sensor, 50-a membrane filtering device, 60-a circulating pipeline, 601-a permeation barrel tank, 602-a backwashing pump, 70-an output pipeline, 701-an output pump, 702-a second filtering device, 80-a liquid conveying pipeline, 801-an additive barrel tank, 802-an additive pump and 90-a nitrogen conveying pipeline.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.

As shown in fig. 1, the present embodiment provides a grinding fluid recycling system, which includes a waste fluid collecting tank 10, a circulating storage tank 30, a membrane filtering device 50, a permeation tank 601, a turbidimeter, and a PLC controller.

In this embodiment, the waste liquid collecting barrel 10 is used for collecting and storing waste liquid containing abrasive particles generated in a CMP process, the waste liquid collecting barrel 10 is communicated with the water inlet end of the circulation storage barrel 30 through a first conveying pipeline 20, and a conveying pump 21 is disposed on the first conveying pipeline 20, so as to convey the waste liquid in the waste liquid collecting barrel 10 to the circulation storage barrel 30 for waiting for treatment.

In this embodiment, be provided with coarse filter 22 and first filter equipment 23 on first pipeline 20, the coarse filtration form sets up before first filter equipment 23, the filter fineness of coarse filter 22 is preferably 80um-100um, coarse filter equipment 22 is preferably basket filter, is convenient for grind impurity with remaining large granule in the grinding waste water and carry out prefiltering, and this kind of filtration mode not only can protect the normal operating of follow-up equipment, and it is extremely convenient to maintain in the use, is convenient for carry out continuous and high-efficient processing to the waste liquid. The first filtering device 23 is a filter element type filter, and the filtering precision of the filter element type filter used in the first filtering device is preferably 15-30 um so as to further remove large-particle-size impurities in the grinding fluid.

In this embodiment, a membrane filtering device 50 is further disposed behind the recycling storage barrel 30, a water inlet end, a backflow end and a permeation end are disposed on the membrane filtering device 50, the backflow end of the recycling storage barrel 30 is communicated with the water inlet end of the membrane filtering device 50 through a second conveying pipeline 40a, and a pressure pump 401 is further disposed on the second conveying pipeline 40 a. The return end of the membrane filtering device 50 is communicated with the return end of the circulating storage barrel 30 through a third conveying pipeline 40b, and a concentration loop is formed between the circulating storage barrel 30 and the membrane filtering device 50. The permeation end of the membrane filtration device 50 is fixedly connected with a circulating pipeline 60, a permeation barrel tank 601 and a backwashing pump 602 are arranged on the circulating pipeline 60, and the backwashing pump 602 is electrically connected with the controller. When the grinding fluid is concentrated, the grinding fluid in the circulating storage barrel 30 is pumped to the membrane filtering device 50 through the second conveying pipeline 40a by the pressure pump 401, under the action of pressure, moisture in the grinding fluid permeates through the filtering membrane of the membrane filtering device 50 so as to achieve the purpose of concentrating the grinding fluid, the solution which does not permeate through the filtering membrane and contains abrasive particles flows back to the circulating storage barrel 30 through the backflow end, the third conveying pipeline 40b and the backflow end, and the solution permeating through the filtering membrane enters the permeation barrel groove 601 through the circulating pipeline 60.

In this embodiment, a pressure sensor 402 is disposed in the second delivery pipe 40a, preferably, the pressure sensor 402 is disposed at the water outlet end of the pressure pump 401, and the pressure sensors 402 are electrically connected to the PLC controller, the pressure sensor 402 is configured to measure the water pressure in the second delivery pipe 40a and upload a detected pressure value to the PLC controller, so as to reflect the blockage of the membrane filtration device 50 by the magnitude of the pressure value to determine the cleaning time, when a detected value of the pressure sensor 402 is less than a set threshold of the PLC controller, which indicates that the ultrafiltration rate is decreased due to the deposition of solute on the membrane surface, and the ultrafiltration rate needs to be backwashed to recover the ultrafiltration rate, at this time, the controller can backwash the membrane filtration device 50 by controlling the backwash pump 602 to pump the solution in the permeate tank 601, so as to ensure the continuous and efficient operation of the filtering membrane and improve the concentration treatment efficiency.

In this embodiment, a stirring device is disposed in the recycling storage barrel 30, and the stirring device is used to stir the solution in the recycling storage barrel 30, optionally, the stirring device is used to stir mechanically or by air flow, so as to uniformly disperse the solute in the recycling storage barrel 30. The turbidimeter is disposed inside the circulating storage barrel 30, and is convenient for detecting the turbidity of the solution in the circulating storage barrel 30. The circulating storage barrel 30 is further provided with an output pipeline 70, and the output pipeline 70 is further provided with an output pump 701. The turbidity meter and the output pump 701 are electrically connected with the controller, the turbidity meter is electrically connected with the controller, so that turbidity data of the solution in the circulating storage barrel 30 can be transmitted to the controller in real time, and when the controller determines the opening of the output pump 701 according to the turbidity data and the set turbidity threshold value, the discharging can be controlled at a proper time.

In this embodiment, the polishing fluid recycling system further includes a plurality of additive tanks 801, the additive tanks 801 are respectively communicated with the circulation storage tank 30 through different infusion pipelines 80, the infusion pipelines 80 are respectively provided with additive pumps 802, the additive pumps 802 are electrically connected to the controller, and optionally, the additive may be a pH adjuster, a stabilizer, an abrasive, or the like.

In this embodiment, two second filtering devices 702 are continuously disposed on the output pipeline 70, the second filtering devices 702 are all core filters, and the filtering precision of the second filtering device 702 located upstream is greater than that of the second filtering device 702 located downstream, the filtering precision of the second filtering device 702 located upstream is preferably 5um to 10um, and the filtering precision of the second filtering device 702 located downstream is 1um to 5 um.

In this embodiment, the waste liquid collecting barrel 10, the circulating storage barrel 30 and the additive barrel groove 801 are all of a closed structure and are all communicated with the nitrogen conveying pipeline 90, so as to ensure that the polishing liquid recycling system works under a micro-positive pressure condition.

The utility model provides a pair of lapping liquid regeneration recovery system's theory of operation is: grinding waste liquid generated in the chemical mechanical grinding process flows into a waste liquid collecting barrel 10 after being collected, and then is pumped into a circulating storage barrel 30 through a conveying pump 21, a rough filtering device 22 and a first filtering device 23, a pressure pump 401 is started to enable the grinding waste liquid in the storage barrel to continuously pass through a membrane filtering device 50 for concentration, concentrated liquid flows back into the circulating storage barrel 30 through a backflow end of the membrane filtering device 50, penetrating liquid of two membrane filtering devices 50 enters a penetrating barrel groove 601 through a circulating pipeline 60 and pumps the penetrating barrel groove 601 out through a backwashing pump 602 in the process of backwashing the membrane filtering device 50 so as to backwash the membrane filtering device 50, the filtering effect of the membrane filtering device 50 is maintained, and backwashing liquid reversely flows into the circulating storage barrel 30 through the backwashing pump 602 so as to ensure the efficient recovery of abrasive particles. The additive in the additive barrel groove 801 is pumped into a circulating system through an additive pump 802, so that the adjustment and correction of the concentration and the state of the grinding fluid are realized. Through observing the testing data of turbidimeter to the concentration of abrasive particle in the solution turbidity reaction solution, when abrasive particle's concentration reached the requirement, the PLC controller was through closing force (forcing) pump 401, opened output pump 701, and concentrated and the lapping liquid of proofreading passes through second filter equipment 702 and accomplishes the recovery promptly, can supply chemical mechanical polishing once more to utilize.

Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art will understand that the present invention can be modified or replaced with other embodiments without departing from the spirit and scope of the present invention, which should be construed as limited only by the appended claims. The technology, shape and construction parts which are not described in detail in the present invention are all known technology.

Claims

1. A grinding fluid regeneration recovery system is characterized in that: comprises a waste liquid collecting barrel (10), a circulating storage barrel (30), a membrane filtering device (50), a permeation barrel groove (601), a turbidity meter and a controller, wherein the waste liquid collecting barrel (10) is communicated with the water inlet end of the circulating storage barrel (30) through a first conveying pipeline (20), the return end of the circulating storage barrel (30) is communicated with the water inlet end of the membrane filtering device (50) through a second conveying pipeline (40a), the return end of the membrane filtering device (50) is communicated with the water return end of the circulating storage barrel (30) through a third conveying pipeline (40b), the permeation end of the membrane filtering device (50) is fixedly connected with a circulating pipeline (60), the circulating pipeline (60) is provided with the permeation barrel groove (601) and a reverse cleaning pump (602), a stirring device is arranged in the circulating storage barrel (30), the turbidity meter is arranged in the circulating storage barrel (30), still be provided with output pipeline (70) on circulation storage bucket (30), be provided with output pump (701) on output pipeline (70), anti-scavenging pump (602), turbidimeter, output pump (701) all with the controller electricity is connected.

2. The slurry reclamation recovery system as recited in claim 1, wherein: the second conveying pipeline (40a) is provided with a pressure pump (401), a pressure sensor (402) is arranged in the second conveying pipeline (40a), and the pressure pump (401) and the pressure sensor (402) are electrically connected with the controller.

3. The slurry reclamation recovery system as recited in claim 1, wherein: the grinding fluid regeneration and recovery system further comprises a plurality of additive barrel grooves (801), the additive barrel grooves (801) are respectively communicated with the circulating storage barrel (30) through different infusion pipelines (80), additive pumps (802) are arranged on the infusion pipelines (80), and the additive pumps (802) are electrically connected with the controller.

4. The slurry reclamation recovery system as recited in claim 3, wherein: the infusion pipeline (80) is provided with a first filtering device (23).

5. The slurry reclamation recovery system as recited in claim 4, wherein: a coarse filtering device (22) is arranged in front of the first filtering device (23).

6. The slurry reclamation recovery system as recited in claim 5, wherein: the filtration precision of the coarse filtration device (22) is 50um-150 um.

7. The slurry reclamation recovery system as recited in claim 1, wherein: the output pipeline (70) is provided with a second filtering device (702).

8. The slurry reclamation recovery system as recited in claim 4 or 7, wherein: the first filtering device (23) and the second filtering device (702) are both filter element type filters.

9. The slurry reclamation recovery system as recited in claim 1, wherein: the waste liquid collecting barrel (10), the circulating storage barrel (30) and the additive barrel groove (801) are all of a closed structure, and the waste liquid collecting barrel (10), the circulating storage barrel (30) and the additive barrel groove (801) are all communicated with the nitrogen conveying pipeline (90).

10. The slurry reclamation recovery system as recited in claim 1, wherein: the controller is a PLC controller.