Chemical liquid concentration monitoring equipment for cds photoetching

Abstract

The utility model discloses chemical liquid concentration monitoring equipment for cds photoetching, which comprises a circulating pipeline, a pump, a controller and a chemical container, the chemical container and the pump are both arranged on the circulating pipeline, the chemical container is connected with an air supply pipe, the circulating pipeline is connected with a liquid inlet pipe and a liquid outlet pipe, the liquid outlet pipe is provided with a liquid outlet valve, and the liquid outlet valve is connected with the controller. A concentration sensor is arranged on the circulating pipeline and electrically connected with the controller, the concentration sensor comprises a sensor body and a multi-way pipe fitting, a liquid channel allowing liquid to pass through is formed in the multi-way pipe fitting, the multi-way pipe fitting comprises a first connector and a second connector, the first connector is connected with the circulating pipeline, and the liquid outlet pipe is connected to the second connector. The sensor main body is connected to the multi-way pipe fitting to detect the concentration of the liquid flowing through the liquid channel and transmit a signal to the controller, the controller is connected with the display screen, and the online detection concentration sensor can reduce the problem of chemical liquid leakage in the process of manual sampling and sample feeding of equipment.

Description

Technical Field

[0001] The utility model relates to a chemical liquid mixing device, in particular to a chemical liquid concentration monitoring device for CDS lithography etching. Background Art

[0002] From semiconductor raw materials to various integrated circuits or discrete devices, hundreds of chemical reactions with different degrees of complexity are utilized in the conversion process. Without a doubt, in the semiconductor manufacturing industry, a large number of special materials and chemicals are required. Chip manufacturing is primarily a chemical process, or more precisely, a series of chemical processes. In recent years, the optoelectronic and photovoltaic semiconductor industries have developed rapidly, with increasingly complex processes, narrower line widths, and higher process requirements. A large number of chemical drugs are required in the production process, and these chemicals are all of certain danger and corrosiveness. In order to safely transport them to the process equipment for use while ensuring the quality of the chemicals, currently, chemical liquids are supplied through chemical liquid supply systems such as CDS / CMS / SDS / CMP. For example, the central chemical liquid supply system is abbreviated as CDS (Center Chemical Dispense System), which is a system that supplies chemical liquids to the production line continuously for 24 hours. The CDS system mainly supplies process technologies such as photolithography development, wafer cleaning, wet etching, thin film preparation, chemical mechanical polishing, grinding, and cleaning accessory carriers.

[0003] The existing chemical liquid supply system generally includes a circulating mixing pipeline and a power pump for driving the liquid to circulate in the circulating mixing pipeline. A chemical barrel for containing chemical stock solution is connected to the circulating mixing pipeline. The power pump drives the chemical stock solution in the chemical barrel to circulate in the circulating mixing pipeline. A liquid adding pipe is connected to the circulating mixing pipeline, and liquid is added to the circulating mixing pipeline through the liquid adding pipe to mix with the chemical stock solution flowing inside to form a chemical liquid with the required concentration.

[0004] After the existing chemical liquid is mixed, it needs to be sampled manually inside the device and then sent to a concentration detection device for concentration detection. There is a risk of sample leakage during the sampling or sample delivery process. In addition, the existing chemical liquid supply system does not have the effect of real-time concentration detection. The concentration of the chemical liquid is understood by sampling - delivering - detecting the mixed chemical liquid. If the concentration of the mixed chemical liquid does not meet the standard, debugging can only be carried out after waiting for the detection result of the sample delivery, which reduces the mixing efficiency. Summary of the Utility Model

[0005] After the above-mentioned chemical liquid mixing is completed, manual sampling needs to be carried out inside the equipment, and then the sample is sent to the detection equipment to detect the concentration, so as to understand whether the mixed chemical liquid meets the required concentration requirements. This process reduces the chemical liquid mixing efficiency, and there is a risk of sample leakage during the sampling or sample delivery process. The present utility model provides a chemical liquid concentration monitoring device for cds lithography etching.

[0006] The technical solution adopted by the present utility model to solve the above technical problems is as follows: A chemical liquid concentration monitoring device for cds lithography etching, including a circulation pipeline, a pump, a controller and a chemical container. The chemical container is provided with a cavity for accommodating the chemical liquid. The chemical container and the pump are both arranged on the circulation pipeline. The pump is used to drive the liquid to circulate in the circulation pipeline. A gas supplement pipe is connected to the chemical container. An inlet pipe for adding liquid into the circulation pipeline and an outlet pipe for the outflow of the mixed liquid are connected to the circulation pipeline. An outlet valve for controlling the opening and closing of the outlet pipe is arranged on the outlet pipe. A concentration sensor for detecting the concentration of the flowing liquid is arranged on the circulation pipeline. The concentration sensor is electrically connected to the controller. The concentration sensor includes a sensor main body and a multi-way pipe fitting. A liquid passage for the liquid to pass through is arranged in the multi-way pipe fitting. The multi-way pipe fitting includes a first joint and a second joint. The first joint is connected to the circulation pipeline, and the outlet pipe is connected to the second joint. The sensor main body is connected to the multi-way pipe fitting to detect the concentration of the liquid flowing through the liquid passage and transmit the signal to the controller. The controller is connected to a display screen for displaying data.

[0007] A further preferred technical solution of the present utility model is as follows: The multi-way pipe fitting includes a third joint. The sensor main body is connected to the third joint. The sensor main body includes a housing, an information acquisition device and an information processing device. The information acquisition device and the information processing device are both accommodated in the housing. A detection window communicating with the third joint is arranged on the housing. The detection window is for the information acquisition device to collect information on the passing liquid. The information acquisition device includes a light source for emitting light, an optical sensing head and a photosensitive device. The photosensitive device is electrically connected to the information processing device. The optical sensing head is arranged at the detection window and contacts the passing liquid to form a reflection interface. The reflection interface is used to reflect the light emitted by the light source. The photosensitive device is used to convert the reflected optical signal into an electrical signal and feedback it to the information processing device. A wire for electrically connecting to the controller is arranged on the information processing device.

[0008] A further preferred technical solution of the present utility model is as follows: Both the housing and the multi-way pipe fitting are made of acid and alkali resistant plastic materials.

[0009] A further preferred technical solution of the present utility model is as follows: An inlet flow controller for measuring the inlet flow rate and an inlet valve for controlling the flow rate of the inlet pipe are arranged on the inlet pipe. The inlet flow controller is located between the inlet valve and the circulation pipeline.

[0010] A further preferred technical solution of the present utility model is that: a first valve and a second valve are provided on the circulation pipeline between the liquid inlet of the pump and the liquid inlet pipe. The first valve is a manual valve, and the second valve is a pneumatic valve. The pump is a pneumatic pump, and a filter is provided on the circulation pipeline between the liquid inlet of the pump and the adjacent valve.

[0011] A further preferred technical solution of the present utility model is that: the housing and the multi-way pipe fitting are made of PTFE material or HDPE material or reinforced polypropylene material.

[0012] A further preferred technical solution of the present utility model is that: the optical sensing head includes a prism and an acid and alkali resistant light-transmitting film. The light-transmitting film is arranged on the surface of the prism facing the liquid channel side and serves as the part in contact with the liquid. The light-transmitting film contacts the liquid and forms the reflection interface.

[0013] A further preferred technical solution of the present utility model is that: the light-transmitting film is a film made of fluorine material.

[0014] A further preferred technical solution of the present utility model is that: a focusing lens is arranged on the optical path of the reflected light between the optical sensing head and the photosensitive device, and the reflected light converges on the photosensitive device after passing through the focusing lens.

[0015] A further preferred technical solution of the present utility model is that: the controller is electrically connected to an alarm device. When the concentration detected by the concentration sensor is higher or lower than the set concentration value, the controller controls the alarm device to give an alarm.

[0016] Compared with the prior art, the advantages of the present utility model are as follows: the liquid to be mixed is added into the circulation pipeline through the liquid inlet pipe, and the pump is started to drive the liquid to circulate and flow in the circulation pipeline for mixing. During the mixing process, the concentration sensor continuously detects the concentration of the liquid circulating in the circulation pipeline and feeds back the signal to the controller, and the data is displayed through the display screen. When the worker observes that the data displayed on the display screen reaches the required concentration, the mixed chemical liquid can be transported out through the liquid outlet pipe to supply the chemical liquid for the semiconductor process. When the concentration sensor detects that the concentration of the liquid circulating in the circulation pipeline does not reach the set concentration, the worker can add liquid through the liquid inlet pipe for debugging to make it reach the set concentration. The on-line detection concentration sensor can reduce the problem of chemical liquid leakage during the sampling and sample delivery processes of manual operation on the equipment, and at the same time improve the efficiency of liquid mixing. Description of the Drawings

[0017] The present utility model will be further described in detail below in conjunction with the accompanying drawings and preferred embodiments. However, those skilled in the art will appreciate that these drawings are only drawn for the purpose of explaining the preferred embodiments and should not be construed as limiting the scope of the present utility model. In addition, unless otherwise specified, the drawings only schematically show the composition or structure of the described object and may include exaggerated displays, and the drawings are not necessarily drawn to scale.

[0018] Figure 1 Schematic diagram of the liquid circulation pipeline for this patent;

[0019] Figure 2 Schematic diagram of the structure of the concentration sensor;

[0020] Figure 3 Cross-sectional view of the concentration sensor;

[0021] Figure 4 Schematic diagram of the information acquisition device and the information processing device;

[0022] Figure 5 Schematic diagram of the structure of the optical sensing head.

[0023] In the figure: 1, chemical container; 2, circulation pipeline; 3, pipeline two; 4, gas supply pipe; 5, concentration sensor; 6, liquid outlet pipe; 7, liquid outlet valve; 8, controller; 9, liquid inlet valve; 10, liquid inlet flow controller; 11, liquid inlet pipe; 12, first valve; 13, second valve; 14, filter; 15, pipeline one; 16, pump; 17, electric wire; 18, sensor body; 19, multi-way pipe fitting; 20, liquid channel; 21, information processing device; 22, housing; 23, information acquisition device; 24, detection window; 25, third joint; 26, first joint; 27, second joint; 28, liquid; 29, reflection interface; 30, light-transmitting film; 31, light source; 32, control circuit board; 33, processing chip; 34, photosensitive device; 35, focusing lens; 36, prism. Detailed implementation manners

[0024] The preferred embodiments of the present utility model will be described in detail below with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are only descriptive and exemplary and should not be construed as limiting the protection scope of the present utility model.

[0025] It should be noted that: similar reference numerals denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it may not be further defined and explained in subsequent drawings.

[0026] Figures 1 - 5As shown in the figure, a chemical liquid concentration monitoring device for CDS lithography etching includes a circulation pipeline 2, a pump 16, a controller 8, and a chemical container 1. The chemical container 1 is provided with a cavity for accommodating the chemical liquid. Both the chemical container 1 and the pump 16 are arranged on the circulation pipeline 2. The pump 16 is used to drive the liquid 28 to circulate in the circulation pipeline 2. A gas supply pipe 4 is connected to the chemical container 1. An inlet pipe 11 for adding the liquid 28 into the circulation pipeline 2 and an outlet pipe 6 for the mixed liquid 28 to flow out are connected to the circulation pipeline 2. An outlet valve 7 for controlling the opening and closing of the outlet pipe 6 is arranged on the outlet pipe 6. A concentration sensor 5 for detecting the concentration of the flowing liquid 28 is arranged on the circulation pipeline 2. The concentration sensor 5 is electrically connected to the controller 8. The concentration sensor 5 includes a sensor body 18 and a multi-way pipe fitting 19. A liquid passage 20 for the liquid 28 to pass through is arranged in the multi-way pipe fitting 19. The multi-way pipe fitting 19 includes a first joint 26 and a second joint 27. The first joint 26 is connected to the circulation pipeline 2, and the outlet pipe 6 is connected to the second joint 27. The sensor body 18 is connected to the multi-way pipe fitting 19 to detect the concentration of the liquid 28 flowing through the liquid passage 20 and transmit the signal to the controller 8. The controller 8 is connected to a display screen for displaying data.

[0027] Preferably, the controller 8 is a conventional existing PLC controller. The display screen can be the one built in the PLC controller 8 or an independent display screen externally connected to the PLC controller 8.

[0028] The chemical container 1 can be a closed chemical barrel, such as a chemical barrel with a lid sealed. The chemical container 1 is arranged on the circulation pipeline 2 to accommodate the liquid 28 for mixing. The liquid 28 in the circulation pipeline 2 passes through the chemical container 1 during circulation. Preferably, an inlet joint and an outlet joint can be arranged on the chemical container 1. The two ends of the circulation pipeline 2 are respectively connected to the inlet joint and the outlet joint to form a closed-loop liquid flow path. When the pump 16 is started, the liquid 28 in the circulation pipeline 2 enters the chemical container 1 from the inlet joint, and then the liquid 28 in the chemical container 1 is pumped back into the circulation pipeline 2 from the outlet joint to form a circulation. A liquid extraction pipe can be arranged on the chemical container 1. The liquid extraction pipe is connected to the outlet joint to extract the liquid 28 in the chemical container 1.

[0029] The gas supply pipe 4 is used to balance the internal pressure of the chemical container 1 when adding liquid through the inlet pipe 11 or extracting liquid through the outlet pipe 6, to avoid the formation of negative pressure or high pressure in the chemical container 1. When the chemical container 1 is a plastic chemical barrel, the chemical barrel is prone to deformation due to negative pressure or high pressure, and the imbalance of the internal air pressure in the chemical barrel will also affect the liquid addition through the inlet pipe 11 and the supply of the liquid 28 through the outlet pipe 6.

[0030] Preferably, the multi-way pipe fitting 19 is a three-way pipe fitting, including a first joint 26, a second joint 27, and a third joint 25. The three joints are respectively connected to the circulation pipeline 2, the outlet pipe 6, and the sensor body 18.

[0031] Preferably, the liquid outlet valve 7 is a conventional regulating manual valve. When it is necessary to output the mixed chemical liquid 28 outward, workers can manually open the liquid outlet valve 7 to connect the liquid outlet pipe 6 with the circulation pipeline 2, so that the mixed chemical liquid 28 can be transported outward from the liquid outlet pipe 6 and supplied to the process technologies such as photolithography development, wafer cleaning, wet etching, thin film preparation, chemical mechanical polishing, grinding, and cleaning of accessory carriers.

[0032] During mixing, the required liquid 28 to be mixed is added into the circulation pipeline 2 through the liquid inlet pipe 11. The pump 16 is started, and the pump 16 drives the liquid 28 to circulate and flow in the circulation pipeline 2 for mixing. During the mixing process, the concentration sensor 5 continuously detects the concentration of the liquid 28 circulating and flowing in the circulation pipeline 2 and feeds back a signal to the controller 8, and the data is displayed through the display screen. When the workers observe that the data displayed on the display screen reaches the required concentration, the mixed chemical liquid can be transported out through the liquid outlet pipe 6 to supply the chemical liquid for the semiconductor manufacturing process. When the concentration sensor 5 detects that the concentration of the liquid 28 circulating and flowing in the circulation pipeline 2 does not reach the set concentration, the workers can add the liquid 28 through the liquid inlet pipe 11 for debugging to make it reach the set concentration. The on-line detection concentration sensor 5 can reduce the problem of chemical liquid leakage during the sampling and sample delivery process of workers in the equipment, and at the same time improve the mixing efficiency of the liquid 28.

[0033] For example, to dilute hydrofluoric acid with a concentration of 49% to a concentration of 1%, a certain amount of 49% concentration hydrofluoric acid to be diluted can be added into the circulation pipeline 2 through the liquid inlet pipe 11, or a certain amount of 49% concentration hydrofluoric acid to be diluted can be stored in the chemical container 1 first, and then pure water for dilution is added through the liquid inlet pipe 11 to be mixed and diluted with the 49% concentration hydrofluoric acid. The pump 16 is started, and the pump 16 drives the 49% concentration hydrofluoric acid and pure water to circulate and flow in the circulation pipeline 2 for mixing. The concentration sensor 5 detects the concentration of the mixed liquid 28 flowing in the circulation pipeline 2. When the concentration sensor 5 detects that the concentration of hydrofluoric acid in the circulation pipeline 2 reaches 1%, the dilution is stopped to obtain the hydrofluoric acid with the required concentration. The hydrofluoric acid with the required concentration can be supplied to the application end through the liquid outlet pipe 6, and a pump can be set at the application end to pump out the hydrofluoric acid in the circulation pipeline 2 and the chemical container 1 for use; when the concentration sensor 5 detects that the concentration of hydrofluoric acid in the circulation pipeline 2 is higher than 1%, the workers can add a certain amount of pure water for re-mixing and dilution to reach the hydrofluoric acid with the required concentration; when the concentration sensor 5 detects that the concentration of hydrofluoric acid in the circulation pipeline 2 is lower than 1%, the workers can add a certain amount of high-concentration hydrofluoric acid for mixing and debugging to reach the hydrofluoric acid with the required concentration.

[0034] Figure 1As shown, in addition, an inlet flow controller 10 for measuring the inlet flow rate and an inlet valve 9 for controlling the magnitude of the inlet flow rate are provided on the inlet pipe 11. The inlet flow controller 10 is located between the inlet valve 9 and the circulation pipeline 2.

[0035] The inlet flow controller 10 is a flowmeter existing on the market, such as a liquid metering controller (turbine flowmeter) of the brand CERTEON. This kind of liquid metering controller has the function of liquid metering control, and can control the amount of liquid 28 transported from the inlet pipe 11 to the circulation pipeline 2 through the inlet flow controller 10, so as to more accurately control the amount of added liquid 28 to achieve the chemical liquid with the required concentration.

[0036] Preferably, the inlet valve 9 is a conventional adjusting hand valve. When it is necessary to add the liquid 28 into the circulation pipeline 2 for mixing and dilution, the worker manually opens the inlet valve 9 so that the external liquid 28 can enter the circulation pipeline 2 through the inlet pipe 11 for mixing.

[0037] A first valve 12 and a second valve 13 are provided on the circulation pipeline 2 between the inlet of the pump 16 and the inlet pipe 11. The first valve 12 is a manual valve, and the second valve 13 is a pneumatic valve. The pump 16 is a pneumatic pump 16. A filter 14 is provided on the circulation pipeline 2 between the inlet of the pump 16 and the adjacent valve. The filter 14 filters the impurity particles in the liquid 28. The first valve 12 is a conventional adjusting hand valve existing on the market, and the second valve 13 is a conventional pneumatic valve existing on the market. The pump 16 is also a conventional pneumatic pump existing on the market. The pneumatic valve is, for example, a pneumatic wafer butterfly valve of the brand Yunjia, model D671F-16Q, and the pneumatic pump is, for example, a pneumatic diaphragm pump of the brand godo / Good, model QBY4-15LTFF.

[0038] The second valve 13 and the pump 16 are set as pneumatic components. The pneumatic components are connected to the air supply equipment through air pipes. An electromagnetic valve is provided on the air pipe, and the electromagnetic valve is electrically connected to the PLC controller. When the equipment is powered on and started, the PLC controller controls the electromagnetic valve to open so that the second valve 13 opens or the pump 16 starts.

[0039] The first valve 12 is set as manual, and the second valve 13 is set as pneumatic. The manual valve is used to control the opening or closing of the circulation pipeline 2, while the pneumatic valve is used to adjust the flow rate of the liquid 28 flowing in the circulation pipeline 2.

[0040] The circulation pipeline 2 includes a pipeline one 15 connecting the liquid outlet joint of the chemical container 1 and the inlet of the pump 16, and a pipeline two 3 connecting the outlet of the pump 16 and the inlet joint of the chemical container 1. The inlet pipe 11, the first valve 12, the second valve 13 and the filter 14 are sequentially arranged on the pipeline one 15. When the pump 16 starts, the liquid 28 passes through the first valve 12, the second valve 13 and the filter 14 in sequence, and then is transported to the chemical container 1 by the pump 16.

[0041] In addition, the controller 8 is electrically connected to an alarm device. When the concentration detected by the concentration sensor 5 is higher or lower than the set concentration value, the controller 8 controls the alarm device to give an alarm. For example, the required concentration of the chemical liquid is 10%. The set range in the controller 8 is 9.8% - 10.2%. When the concentration detected by the concentration sensor 5 is greater than 10.2% or less than 9.8%, the controller 8 controls the alarm device to give an alarm, and the worker adjusts the chemical liquid in the circulation pipeline 2 again; when the concentration detected by the concentration sensor 5 is within the range of 9.8% - 10.2%, it means that the concentration after mixing meets the usage requirements. This structure can avoid producing defective products during the dilution and blending process.

[0042] The alarm device is, for example, an alarm lamp or an alarm sound - making device.

[0043] Figures 2 - 5 As shown, the sensor body 18 includes a housing 22, an information processing device 21, and an information collection device 23. The information processing device 21 and the information collection device 23 are both housed in the housing 22. The housing 22 is fixedly connected to the multi - way pipe fitting 19. A detection window 24 communicating with the third joint 25 is provided on the housing 22. The detection window 24 allows the information collection device 23 to collect information on the passing liquid 28. The information collection device 23 includes a light source 31 that emits light, an optical sensing head, and a photosensitive device 34. The photosensitive device 34 is electrically connected to the information processing device 21. The optical sensing head is disposed at the detection window 24 and contacts the passing liquid 28 to form a reflection interface 29. The reflection interface 29 is used to reflect the light emitted by the light source 31. The photosensitive device 34 is used to convert the reflected optical signal into an electrical signal and feedback it to the information processing device 21. The information processing device 21 receives the electrical signal output by the photosensitive device 34 and performs image processing and data analysis, thereby completing the detection of the concentration of the liquid 28 and obtaining the concentration of the liquid 28 passing through the liquid passage 20. A wire 17 for electrically connecting to the controller 8 is provided on the information processing device 21. The concentration sensor 5 is electrically connected to the controller 8 through this wire 17. The concentration sensor 5 detects data and feeds back the signal to the controller 8 through the wire 17.

[0044] Figure 4 、 Figure 5 As shown, preferably, the optical sensing head includes a prism 36 and an acid - and alkali - resistant light - transmissive film 30. The prism 36 is a triangular prism. The light - transmissive film 30 is disposed on the surface of the prism 36 facing the liquid passage 20 and serves as the part in contact with the liquid 28. When the liquid 28 passes through the liquid passage 20, the light - transmissive film 30 contacts the liquid 28 to form the above - mentioned reflection interface 29.

[0045] The light-transmitting film 30 seals the detection window 24 to prevent the liquid 28 flowing through the liquid channel 20 from entering the housing 22. A sealing ring can be provided between the light-transmitting film 30 and the housing 22 to make the sealing performance between the light-transmitting film 30 and the detection window 24 better. The sealing ring can be made of polytetrafluoroethylene material.

[0046] Working principle: The light emitted by the light source 31 enters the prism 36 from the S1 surface of the prism 36, and then enters the light-transmitting film 30 after being refracted through the interface S4 between the prism 36 and the light-transmitting film 30. These lights are reflected on the reflection interface 29S2 formed by the contact between the light-transmitting film 30 and the liquid 28. The reflected light on the reflection interface 29S2 then enters the prism 36 again through the interface S4, and then exits the prism 36 through the S3 surface of the prism 36. The photosensitive device 34 receives the light exiting from the S3 surface of the prism 36, converts the optical signal into an electrical signal and outputs it to the information processing device 21, and finally obtains the concentration of the liquid 28.

[0047] Preferably, the light-transmitting film 30 is a fluorine film made of fluorine material. The film has good chemical stability and good acid and alkali resistance, and is arranged on the surface of the prism 36 as the contact part with the liquid 28, which can effectively prevent the liquid 28 from corroding the prism 36 and ensure the stability of detection.

[0048] This patent uses the principle of a critical angle refractometer to measure the refractive index to detect the concentration of the liquid 28 passing through the liquid channel 20. The refractometer measures the refractive index of the liquid 28 based on the principle of total internal reflection of light, also known as the critical angle method. This detection method is an existing detection method. The information processing device 21 and the information acquisition device 23 are the same as those of the existing refractometer, and reference can be made to Patent CN215985735U and Patent CN102012359A.

[0049] Preferably, the photosensitive device 34 is a linear CCD (linear charge-coupled device) / CMOS (linear complementary metal oxide semiconductor) array, which includes a plurality of pixels and the plurality of pixels are arranged in a one-dimensional linear manner along the straight line direction of light dispersion. Each pixel can include components such as a photosensitive diode, a storage unit, and an amplifier circuit.

[0050] The information processing device 21 includes a processing chip 33 and a control circuit board 32. The processing chip 33 is electrically connected to the control circuit board 32. The above-mentioned photosensitive device 34 is electrically connected to the processing chip 33. The processing chip 33 receives the electrical signal output by the photosensitive device 34 and performs image processing and data analysis. The processing chip 33 conveys the analysis result to the control circuit board 32. The above-mentioned light source 31 is also electrically connected to the control circuit board 32. The processing chip 33 can be a CPU processing module.

[0051] The detection window 24 is provided at the bottom of the housing 22, and a wire 17 for connecting the control circuit board 32 is provided at the top of the housing 22. The wire 17 can be used to connect to an external controller 8.

[0052] A focusing lens 35 is provided on the optical path of the reflected light between the optical sensing head and the photosensitive device 34. After passing through the focusing lens 35, the reflected light converges on the photosensitive device 34. Preferably, the focusing lens 35 can be a convex lens.

[0053] Both the housing 22 and the multi-way pipe fitting 19 are made of acid- and alkali-resistant plastic materials, which can effectively prevent the housing 22 and the multi-way pipe fitting 19 from being corroded when used in an acid-alkali environment, thereby increasing the service life of the concentration detection sensor.

[0054] Preferably, the housing 22 and the multi-way pipe fitting 19 are made of PTFE (polytetrafluoroethylene).

[0055] In another solution, preferably, the housing 22 and the multi-way pipe fitting 19 are made of HDPE (high-density polyethylene).

[0056] In another solution, preferably, the housing 22 and the multi-way pipe fitting 19 are made of reinforced polypropylene.

[0057] The above-mentioned plastic materials have good chemical stability and excellent acid- and alkali-resistance. The materials of the housing 22 and the multi-way pipe fitting 19 in this patent are not limited to the above three, and other plastic materials with the same characteristics commonly available in the market are also applicable to this patent.

[0058] Regarding the structure of the above-mentioned optical sensing head, this patent also has another structure. The specific content is as follows:

[0059] Preferably, the optical sensing head includes a prism 36. The prism 36 is a triangular prism. One surface of the prism 36 facing the liquid channel 20 closes the detection window 24 and serves as the part in contact with the liquid 28. When the liquid 28 passes through the liquid channel 20, the surface of the prism 36 facing the liquid channel 20 contacts the liquid 28 to form the above-mentioned reflection interface 29.

[0060] In addition, a sealing ring can be provided between the prism 36 and the housing 22 to make the sealing between the prism 36 and the detection window 24 better. The sealing ring can be made of polytetrafluoroethylene.

[0061] Working principle: The light rays emitted by the light source 31 enter the prism 36 from the S1 surface of the prism 36. These light rays are reflected on the reflection interface 29S2 formed by the contact between the prism 36 and the liquid 28. The light rays reflected on the reflection interface 29S2 exit the prism 36 through the S3 surface of the prism 36. The photosensitive device 34 converts the reflected optical signal into an electrical signal and outputs it to the information processing device 21, and finally the concentration of the liquid 28 is obtained.

[0062] The above has introduced the chemical liquid concentration monitoring device for CDS lithography etching provided by the present utility model. Specific examples are used in this article to elaborate on the principle and implementation manner of the present utility model. The description of the above embodiments is only used to help understand the present utility model and its core idea. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present utility model, several improvements and modifications can still be made to the present utility model, and these improvements and modifications also fall within the protection scope of the claims of the present utility model.

Claims

1. A chemical liquid concentration monitoring device for CDS lithography etching, characterized in that, It includes a circulating pipeline, a pump, a controller and a chemical container. There is a cavity for containing chemical liquid in the chemical container. Both the chemical container and the pump are arranged on the circulating pipeline. The pump is used to drive the liquid to circulate in the circulating pipeline. A gas supply pipe is connected to the chemical container. An inlet pipe for adding liquid into the circulating pipeline and an outlet pipe for the mixed liquid to flow out are connected to the circulating pipeline. An outlet valve for controlling the opening and closing of the outlet pipe is arranged on the outlet pipe. A concentration sensor for detecting the concentration of the flowing liquid is arranged on the circulating pipeline. The concentration sensor is electrically connected to the controller. The concentration sensor includes a sensor body and a multi-way pipe fitting. There is a liquid passage for the liquid to pass through in the multi-way pipe fitting. The multi-way pipe fitting includes a first joint and a second joint. The first joint is connected to the circulating pipeline, and the outlet pipe is connected to the second joint. The sensor body is connected to the multi-way pipe fitting to detect the concentration of the liquid flowing through the liquid passage and transmit a signal to the controller. The controller is connected to a display screen for displaying data.

2. The chemical liquid concentration monitoring device for CDS lithography etching according to claim 1, characterized in that, The multi-way pipe fitting includes a third joint. The sensor body is connected to the third joint. The sensor body includes a housing, an information acquisition device and an information processing device. Both the information acquisition device and the information processing device are housed in the housing. A detection window communicating with the third joint is arranged on the housing. The detection window is for the information acquisition device to acquire information about the passing liquid. The information acquisition device includes a light source for emitting light, an optical sensing head and a photosensitive device. The photosensitive device is electrically connected to the information processing device. The optical sensing head is arranged at the detection window and contacts the passing liquid to form a reflection interface. The reflection interface is used to reflect the light emitted by the light source. The photosensitive device is used to convert the reflected optical signal into an electrical signal and feedback it to the information processing device. An electric wire for electrically connecting to the controller is arranged on the information processing device.

3. The chemical liquid concentration monitoring device for CDS lithography etching according to claim 2, wherein Both the housing and the multi-way pipe fitting are made of acid and alkali resistant plastic materials.

4. The chemical liquid concentration monitoring device for CDS lithography etching according to claim 1, characterized in that, An inlet flow controller for measuring the inlet flow rate and an inlet valve for controlling the flow rate of the inlet pipe are arranged on the inlet pipe. The inlet flow controller is located between the inlet valve and the circulating pipeline.

5. The chemical liquid concentration monitoring device for CDS lithography etching according to claim 1, characterized in that, A first valve and a second valve are arranged on the circulating pipeline between the inlet of the pump and the inlet pipe. The first valve is a manual valve, and the second valve is a pneumatic valve. The pump is a pneumatic pump. A filter is arranged on the circulating pipeline between the inlet of the pump and the adjacent valve.

6. The chemical liquid concentration monitoring device for CDS lithography etching according to claim 3, characterized in that, Both the housing and the multi-way pipe fitting are made of PTFE material or HDPE material or reinforced polypropylene material.

7. The chemical liquid concentration monitoring device for CDS lithography etching according to claim 2, characterized in that, The optical sensing head includes a prism and an acid and alkali resistant light-transmitting film. The light-transmitting film is arranged on the surface of the prism facing the liquid passage side and serves as the part in contact with the liquid. The light-transmitting film contacts the liquid to form the reflection interface.

8. The chemical liquid concentration monitoring device for CDS lithography etching according to claim 7, characterized in that, The light-transmitting film is a film made of fluorine material.

9. The chemical liquid concentration monitoring device for CDS lithography etching according to claim 2, wherein A focusing lens is arranged on the optical path of the reflected light between the optical sensing head and the photosensitive device. The reflected light converges on the photosensitive device after passing through the focusing lens.

10. The chemical liquid concentration monitoring device for CDS lithography etching according to claim 1, wherein The controller is electrically connected to an alarm device. When the concentration detected by the concentration sensor is higher or lower than the set concentration value, the controller controls the alarm device to give an alarm.

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