KR100992116B1 - Apparatus for measuring concentration of chemical solution - Google Patents

Abstract

A chemical liquid concentration measuring device is provided. The chemical liquid concentration measuring apparatus according to the embodiment of the present invention is supplied with a chemical liquid from the chemical liquid tank storing the chemical liquid concentration measuring unit for measuring the concentration of the chemical liquid, and a displacement solution for discharging the chemical liquid measured from the concentration measuring unit to the outside Discharged from the substitution liquid supply unit for supplying the concentration measuring unit, the chemical liquid supply pipe for supplying the chemical liquid or the substitution liquid to the concentration measuring unit, and the bypass pipe and the concentration measuring unit for bypassing a part of the chemical liquid or the substitution liquid from the concentration measuring unit and discharging it to the outside And a chemical liquid discharge pipe for discharging the chemical liquid or the replacement liquid to the outside.

Chemical liquid concentration measuring device, substitution liquid supply part, bypass pipe

Description

Apparatus for measuring concentration of chemical solution

The present invention relates to a chemical liquid concentration measuring apparatus, and more particularly to a chemical liquid concentration measuring apparatus capable of measuring the concentration of the chemical liquid quickly and accurately.

Recently, liquid crystal display (LCD) devices, plasma display panel (PDP) devices, and the like have been rapidly replacing conventional CRTs as display devices for displaying images. These use substrates commonly referred to as flat panel displays (FPDs).

In order to manufacture a flat panel display, many processes such as a substrate fabrication process, a cell fabrication process, and a module fabrication process must be performed. In particular, in the substrate fabrication process, in order to form various patterns on the substrate, photolithography techniques are generally applied, starting with a cleaning process.

Photolithography technology includes the steps of applying a photoresist, a photoresist, to a film formed on a substrate, drying the photoresist to volatilize a solvent of the photoresist, and at a relatively low temperature. Soft baking the photoresist, applying a photo mask to the photoresist, exposing the photoresist film according to a pattern formed on the photo mask, and developing the exposed photoresist film. And hard baking the developed photoresist at a relatively high temperature, and patterning the film quality exposed between the photoresist films.

Various liquid chemicals or pure water (DI water) are frequently used in the manufacturing process of such a flat panel display device. Various liquid chemicals include, for example, acidic solutions such as hydrofluoric acid, sulfuric acid, nitric acid, phosphoric acid, and the like, alkaline solutions containing potassium hydroxide, sodium hydroxide, ammonium, and the like, and chemicals used in cleaning liquids.

Accordingly, the substrate processing apparatus is provided with a chemical liquid supply device for supplying and circulating various liquid chemicals or DI water (hereinafter referred to as chemical liquid). The chemical liquid supply device has a structure in which a chemical liquid is supplied to a substrate processing unit from a chemical liquid tank storing a chemical liquid using a pump or the like, and the used chemical liquid is recovered to the chemical liquid tank again. The chemical liquid tank is mostly located at the bottom of the facility frame of the substrate processing apparatus.

On the other hand, since the result of the substrate treatment process varies depending on the concentration of the chemical liquid supplied from the chemical liquid supply device to the substrate processing unit, there is a need to provide a chemical liquid of the correct concentration.

In general, the chemical liquid concentration measuring device receives the chemical liquid at a predetermined position of the chemical liquid tank to measure the concentration of the chemical liquid stored in the chemical liquid tank, and measures the chemical liquid concentration. The chemical is supplied to the substrate processing unit to proceed with the process. In addition, after a single concentration measurement for a more accurate concentration measurement, in order to initialize or calibrate the concentration measurement device to replace the chemical liquid in the device using pure water.

Therefore, there is a need for a chemical liquid concentration measuring apparatus capable of measuring the concentration of the chemical liquid more quickly and accurately.

The present invention is designed to improve the above problems, the technical problem to be achieved by the present invention is to reduce the initializing or calibration time of the concentration measuring device and to reduce the residual amount of the chemical liquid chemical concentration that can quickly and accurately measure the concentration of the chemical liquid It is to provide a measuring device.

The technical problem of the present invention is not limited to those mentioned above, and another technical problem which is not mentioned can be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the chemical liquid concentration measuring apparatus according to an embodiment of the present invention, the chemical liquid from the chemical liquid tank storing the chemical liquid concentration measurement unit for measuring the concentration of the chemical liquid and the concentration measuring unit from the Substituent supply unit for supplying the solution to the concentration measuring unit for discharging the measured chemical solution to the outside, a chemical solution supply pipe for supplying the chemical or the replacement solution to the concentration measuring unit, and the chemical or the replacement solution from the concentration measuring unit Bypass a portion of the bypass pipe to discharge to the outside and the chemical liquid discharge pipe discharged from the concentration measuring unit to the outside to the chemical liquid discharge pipe.

According to the chemical liquid concentration measuring apparatus of the present invention as described above has one or more of the following effects.

First, there is an advantage in that the residual amount of the chemical liquid remaining in the chemical liquid concentration measuring apparatus can be reduced by installing the substitution liquid supply unit for supplying the replacement liquid for the initialization or correction of the concentration measuring unit at the front end of the chemical liquid supply pipe.

Second, by bypassing a part of the chemical liquid or the replacement liquid through the bypass pipe has the advantage of reducing the time required to replace the chemical liquid supplied from the chemical tank or the time required for the calibration or initialization of the concentration measurement unit using the replacement liquid.

Third, there is an advantage to measure the concentration of the chemical liquid by receiving the chemical liquid from a plurality of points or a plurality of chemical liquid tank of the chemical liquid tank using one concentration measuring unit.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Thus, in some embodiments, well known process steps, well known structures and well known techniques are not described in detail in order to avoid obscuring the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. As used herein, including and / or comprising includes the presence or addition of one or more other components, steps, operations and / or elements other than the components, steps, operations and / or elements mentioned. Use in the sense that does not exclude. And "and / or" include each and any combination of one or more of the mentioned items.

In addition, the embodiments described herein will be described with reference to cross-sectional and / or schematic views, which are ideal illustrations of the invention. Accordingly, shapes of the exemplary views may be modified by manufacturing techniques and / or tolerances. Accordingly, the embodiments of the present invention are not limited to the specific forms shown, but also include variations in forms generated by the manufacturing process. In addition, each component in each drawing shown in the present invention may be shown to be somewhat enlarged or reduced in view of the convenience of description. Like reference numerals refer to like elements throughout.

Hereinafter, the present invention will be described with reference to the drawings for describing a chemical solution concentration measuring apparatus according to embodiments of the present invention.

1 is a view schematically showing a structure of a general substrate processing apparatus, and FIG. 2 is a view showing an example in which two chemical liquid tanks are provided in the substrate processing apparatus of FIG. 1.

Referring to FIG. 1, the substrate processing apparatus 1 may largely include a substrate processing unit 10, a chemical liquid tank 20, and a chemical liquid supply pump 30. Here, the substrate processing apparatus 1 may mean various kinds of apparatuses for treating the substrate G by using various chemical liquids (including pure water) such as a photosensitive liquid coating apparatus and a cleaning apparatus.

First, referring to the substrate processing unit 10, the substrate processing unit 10 may include a spray nozzle 11 for injecting a chemical liquid toward the substrate G, and a substrate transfer unit 12 for transferring the substrate G in one direction. And a treatment tank 13 for collecting the injected chemical liquid. The substrate processing unit 10 includes a photoresist coating process, an exposure process, a developing process, an etching process, a stripping process, and a cleaning process in the manufacturing process of the flat panel display device. It may mean a space that proceeds. Therefore, in the substrate processing unit 10, various processes for the substrate G may be performed using various chemical liquids supplied from the chemical liquid supply device. At this time, the type, flow rate, etc. of the chemical liquid supplied to the substrate processing unit 10 may be adjusted through the chemical liquid supply device. Here, the chemical liquid supply device may mean a configuration including a treatment tank 13, a chemical liquid tank 20, a chemical liquid supply pump 30, and a plurality of pipes 41, 42, and 43 in FIG. 1.

The injection nozzle 11 may be in the form of a spray nozzle in which a plurality of nozzles are arranged at regular intervals to inject the chemical liquid, respectively, as shown in FIG. 1, or may be in the form of a slit nozzle that discharges the chemical liquid through a long discharge port. .

The substrate transfer unit 12 includes a plurality of transfer shafts disposed at regular intervals perpendicular to the transfer direction of the substrate G, and a plurality of rollers for supporting and transferring the substrate G to each transfer shaft. Can be configured. The substrate transfer unit 12 may transfer the rotational force of a driving device such as a motor to each transfer shaft through a power transmission member such as a pulley and a belt connected to an end of each transfer shaft to transfer the substrate G. have.

The treatment tank 13 is installed in the lower part of the substrate G and collects the chemical liquid after the process for the substrate G is collected. Pipe 43 may be connected. That is, the chemical liquid injected in the substrate processing unit 10 may be received and recovered into the chemical liquid tank 20. On the other hand, the structure of the substrate processing unit 10 is not limited to this, it can be changed by those skilled in the art.

The chemical liquid tank 20 has a substantially rectangular parallelepiped shape and provides a space for storing the chemical liquid used in the substrate processing unit 10. The chemical liquid tank 20 supplies the chemical liquid to the injection nozzle 11 of the substrate processing unit 10 and the substrate processing unit 10. The chemical liquid can be recovered from the treatment tank 13. The chemical tank 20 may be connected with a pipe (not shown) for supplying a new chemical liquid and a pipe (not shown) for discharging the reused chemical liquid.

In FIG. 1, the case of using one chemical liquid tank 20 is exemplified, but the number and arrangement of the chemical liquid tank 20 can be changed by those skilled in the art. For example, as illustrated in FIG. 2, two chemical liquid tanks 21 and 22 may be installed and used. In this case, the substrate processing unit 10 may be separated from one chemical liquid tank (the first chemical liquid tank 21). In the other chemical liquid tank (second chemical liquid tank 22), such as chemical liquid concentration control, etc. can be performed while the chemical liquid is supplied to the furnace, it is possible to carry out a continuous process on the substrate G without delay. At this time, the third pipe 43 for recovering the chemical liquid from the treatment tank 13 is divided into a pipe 43a connected to the first chemical tank 21 and a pipe 43b connected to the second chemical tank 22, The pipe 41a connected to the first chemical tank 21 and the pipe 41b connected to the second chemical tank 22 may be combined into the first pipe 41 connected to the chemical supply pump 30.

Meanwhile, the chemical liquid tank 20 may be connected to a chemical liquid concentration measuring device for measuring the concentration of the chemical liquid and a concentration controller for adjusting the concentration of the chemical liquid. This will be described later in detail with reference to FIGS. 3 to 5.

The chemical liquid supply pump 30 may supply the chemical liquid stored in the chemical liquid tank 20 to the slit nozzle 11 of the substrate processing unit 10. That is, the chemical liquid supply pump 30 may supply the chemical liquid from the chemical liquid tank 20 to the substrate processing unit 10. As the chemical liquid supply pump 30, various kinds of pumps, such as a rotary pump and a centrifugal pump, may be used. At this time, the chemical liquid supply pump 30 may pressurize the pressure of the chemical liquid supplied to the substrate processing unit 10 to the required process pressure according to the type and characteristic of the process performed in the substrate processing unit 10.

The number and configuration of the chemical liquid supply pump 30 can be changed depending on the size of the chemical liquid tank 20, the flow rate of the chemical liquid supplied to the substrate processing unit 10, and the like.

Meanwhile, the chemical liquid tank 20 may be provided with a temperature control device (not shown) such as a heating unit for heating the chemical liquid so that the chemical liquid stored therein is maintained at an appropriate temperature that can be used in the substrate processing unit 10. . At this time, the temperature of the chemical liquid used in the substrate processing unit 10 may vary depending on the type and characteristics of the process. In addition, the chemical tank 20 may also be provided with various control devices for adjusting the pressure, concentration, level of the chemical liquid.

Meanwhile, the substrate processing apparatus 1 according to the exemplary embodiment of the present invention supplies the chemical liquid from the chemical liquid tank 20 to the substrate processing unit 10, and recovers the chemical liquid from the substrate processing unit 10 to the chemical liquid tank 20. It may include a plurality of pipes (41, 42, 43) as a path for. That is, as shown in FIG. 1, the substrate processing apparatus 1 includes a first pipe 41, a chemical liquid supply pump 30, and a substrate processing unit 10 that connect the chemical liquid tank 20 and the chemical liquid supply pump 30. The second pipe 42 to connect the injection nozzle of the) and the third pipe 43 to connect the processing tank 13 and the chemical tank 20 of the substrate processing unit 10 may be included. The configuration of such a pipe is not limited to this, and can be changed by those skilled in the art. In addition, a plurality of pipes 41, 42, 43 may be provided with a flow control valve (not shown) for adjusting the flow rate of the chemical liquid.

Hereinafter, the structure and operation of the chemical liquid concentration measuring apparatus 100 will be described with reference to FIGS. 3 to 5.

3 is a view schematically showing the structure of a chemical liquid concentration measuring apparatus according to an embodiment of the present invention.

As shown in Figure 3, the chemical liquid concentration measuring apparatus 100 according to an embodiment of the present invention is a concentration measuring unit 110, a substitution liquid supply unit 120, the chemical liquid supply pipe 150, the bypass pipe 170 and The chemical liquid discharge pipe 160 may be included.

The concentration measuring unit 110 may receive the chemical liquid from the chemical liquid tank 20 storing the chemical liquid and measure the concentration of the chemical liquid. That is, the concentration measuring unit 110 may measure the concentration of the chemical liquid by measuring the mixing ratio of the plurality of treatment liquids with respect to the chemical liquids composed of the plurality of treatment liquids mixed to process the substrate. The concentration measuring unit 110 will be described later in detail with reference to FIG. 5.

The substitution solution supply unit 120 may supply a substitution solution for discharging the chemical liquid measured from the concentration measurement unit 110 to the concentration measurement unit 110. That is, in the case where the substitution liquid is to measure the concentration of the chemical liquid at a predetermined position (first measuring unit) of the chemical liquid tank 20 and then to measure the concentration of the chemical liquid at another position (second measuring unit), the concentration measuring unit ( It may serve to remove the chemical liquid supplied from the previous position (first measuring unit) from the concentration measuring unit 110 for initialization or calibration (hereinafter, referred to as correction) of 110. In this case, the treatment liquid may include the chemical liquid measured by the concentration measuring unit 110, as well as the concentration measuring unit 110, as well as the chemical liquid supply pipe 150, the chemical liquid discharge tube 160, and the like. Can be discharged to the outside. Preferably, DI water can be used as a substitution liquid.

The chemical solution supply pipe 150 may serve as a passage for supplying a chemical solution or a replacement solution for the correction of the concentration measuring unit 110 to measure the concentration from the chemical tank 20 to the concentration measuring unit 110. As shown in Figure 3, the chemical liquid supply pipe 150 is connected to the inlet side of the concentration measuring unit 110, the first supply pipe 151 for supplying the chemical liquid from the first measuring unit of the chemical liquid tank 20, the chemical liquid It may include a second supply pipe 152 for supplying a chemical liquid from the second measuring unit of the tank 20 and a third supply pipe 153 for supplying a replacement liquid from the substitution liquid supply unit 120. In addition, flow control valves 152, 154, and 156 may be installed on the first supply pipe 151 to the third supply pipe 153 to adjust the flow rate of the chemical liquid or the replacement liquid, respectively.

On the other hand, the chemical liquid supply pipe 150 is a 4-WAY valve for selectively supplying the chemical liquid to the concentration measurement unit 110 for the correction of the chemical liquid or the concentration measuring unit 110 to measure the concentration from the chemical liquid tank ( 140 may be installed. For example, when the concentration measuring unit 110 intends to measure the concentration of the chemical liquid supplied from the first measuring unit, the 4-WAY valve 140 opens the first supply pipe 151 connected to the first measuring unit, The second supply pipe 152 connected to the second measurement unit and the third supply pipe 153 connected to the substitution solution supply unit 120 may be blocked.

In the chemical liquid concentration measuring apparatus 100 according to an embodiment of the present invention, the substitution liquid supply unit 120 is installed at the front end of the chemical liquid supply pipe 150 and by supplying the substitution liquid using the 4-WAY valve 140 When supplying a replacement solution for correction of the concentration measuring unit 110, the residual amount of the chemical solution remaining in the chemical solution concentration measuring apparatus 100 may be reduced.

On the other hand, the chemical liquid concentration measuring apparatus 100 according to an embodiment of the present invention may be connected to the chemical liquid tank 20 to measure the concentration of the chemical liquid supplied from the first measuring unit and the second measuring unit.

4 is a view showing an example in which the chemical liquid concentration measuring apparatus according to an embodiment of the present invention is connected to the chemical liquid tank.

As shown in FIG. 4, the concentration controller 50 may be connected to the chemical liquid tank 20 to adjust the concentration of the chemical liquid stored in the chemical liquid tank 20 by receiving the concentration value measured by the concentration measuring unit 110. have.

The concentration control unit 50 compares the mixing ratio of the processing liquids measured by the concentration measuring unit 110 with a mixing ratio preset according to the process conditions, and when not suitable for the set mixing ratio, among the processing liquids included in the chemical liquid. At least one of the flow rate may be adjusted to adjust the concentration of the chemical liquid. The concentration controller 50 may be connected with pipes 44 and 45 for receiving the chemical liquid from the chemical liquid tank 20 and supplying the chemical liquid whose concentration is adjusted to the chemical liquid tank 20 again. In addition, the concentration control unit 50 may be connected to a plurality of processing liquid storage tank, a processing liquid supply pipe, a flow control valve for supplying a plurality of processing liquids.

Preferably, the concentration measuring unit 110 measures the concentration of the chemical liquid on the circulation pipe 51 for circulating the chemical liquid discharged from the concentration controller 50 to the chemical liquid tank 20, or the substrate in the chemical liquid tank 20 The concentration of the chemical liquid may be measured on the supply pipe phase 52 for supplying the chemical liquid to the treatment unit. That is, the first measuring unit of the concentration measuring unit 110 may be connected to the circulation pipe phase 51, and the second measuring unit may be connected to the supply piping phase 52. Therefore, the concentration measuring unit 110 may first measure the concentration of the chemical liquid in the circulation pipe phase 51, correct it with a substitution liquid, and then measure the concentration of the chemical liquid in the supply pipe phase 52 again. At this time, the concentration measuring unit 110 may send the resulting value to the concentration control unit 50 to adjust the concentration of the chemical liquid.

As another example, as described above, the substrate processing apparatus 1 may include two chemical liquid tanks 20 as shown in FIG. 2, in which case the concentration measuring unit 110 stores the first chemical liquid tank for storing the chemical liquid. The chemical liquid may be sequentially supplied from 21 and the second chemical liquid tank 22 to measure the concentration of the chemical liquid. That is, the first measuring unit of the concentration measuring unit 110 may be connected to the circulation pipe or the supply pipe of the first chemical liquid tank 21, and the second measuring unit may be connected to the circulation pipe or the supply pipe of the second chemical liquid tank 22. have. Accordingly, the concentration measuring unit 110 first measures the concentration of the chemical liquid with respect to the first chemical liquid tank 21, corrects it with a substitution liquid, and then measures the concentration of the chemical liquid with respect to the second chemical liquid tank 22. can do. In this case as well, the concentration measuring unit 110 may send the result value to the concentration controller 50 to adjust the concentration of the chemical liquid.

As described above, in the case of the chemical liquid concentration measuring apparatus 100 according to the exemplary embodiment of the present invention, a plurality of points or the plurality of chemical liquid tanks 21 and 22 of the chemical liquid tank 20 using one concentration measuring unit 110. The concentration of the chemical can be measured by receiving the chemical from the solution. Here, an example in which one or two chemical liquid tanks 20 are provided will be described, but the present invention is not limited thereto and can be changed by those skilled in the art.

Referring back to FIG. 3, the chemical liquid supply pipe 150 may be provided with a cooler 130 that lowers the chemical liquid to a temperature usable by the concentration measuring unit 110. In general, the temperature of the chemical liquid stored in the chemical liquid tank 20 is about 70 ℃, if necessary, in order to measure the concentration of the chemical liquid in the concentration measuring unit 110 it is necessary to lower the temperature of the chemical liquid to approximately 30 ℃. Therefore, the cooler 130 may lower the temperature supplied from the chemical liquid tank 20 by the required temperature and supply it to the concentration measuring unit 110.

The chemical liquid discharge tube 160 may discharge the chemical liquid or the replacement liquid discharged from the concentration measuring unit 110 to the outside of the chemical liquid concentration measuring apparatus 100. The chemical liquid or the replacement liquid discharged through the chemical liquid discharge pipe 160 is discharged to the outside of the substrate processing apparatus 1 through an outlet provided in the substrate processing apparatus 1, or the chemical liquid tank 20 and the replacement liquid supply unit 120. ) And the like can be reused. On the other hand, on the chemical liquid discharge pipe 160 may be provided with a flow rate control valve (161, 162, 163) for controlling the flow rate of the chemical liquid or the replacement liquid discharged.

As shown in FIG. 3, the chemical liquid concentration measuring apparatus 1 according to the exemplary embodiment of the present invention includes a bypass pipe 170 branched from the concentration measuring unit 110 and connected to the chemical liquid discharge pipe 160. can do. The bypass pipe 170 may bypass a part of the chemical liquid or the replacement liquid from the concentration measuring unit 110 to be discharged to the outside. Therefore, it is possible to shorten the time for replacing the chemical liquid supplied from the first measuring unit or the second measuring unit or the correction time of the concentration measuring unit 110 using the substitution liquid. On the other hand, on the bypass pipe 170 may be provided with a flow rate control valve 171 for adjusting the flow rate of the chemical liquid or the replacement liquid discharged.

5 is a view schematically showing the structure of the concentration measuring unit in the chemical liquid concentration measuring apparatus according to an embodiment of the present invention.

As shown in FIG. 5, the concentration measuring unit 110 may include a bubble removing unit 111, a concentration measuring unit 112, a temperature sensor 113, and a capillary 114.

First, the bubble removing unit 111 may remove the bubbles contained in the chemical liquid by receiving the chemical liquid from the chemical liquid supply pipe 150. In addition, the concentration measuring unit 112 may detect the amount of light from the chemical liquid and measure the concentration of the chemical liquid. When measuring the concentration of the chemical liquid in the concentration measuring unit 112, the flow rate of the chemical liquid flowing in the concentration measuring unit 112 is about 20 to 40 cc. Since a method of measuring the concentration of the chemical liquid by detecting the amount of light from various solutions including the chemical liquid is well known, a detailed description thereof will be omitted. The temperature sensor 113 may measure the temperature of the chemical liquid, and the capillary 114 is connected to the chemical liquid discharge tube 160, and removes air bubbles from the chemical liquid to the outside of the concentration measuring unit 110. Can be discharged. In addition, the bubble removing unit 111, the concentration measuring unit 112, the temperature sensor 113 and the capillary 114 may be connected by a pipe, a pipe such as a PTA tube may be used.

Preferably, as shown in FIG. 5, the bypass pipe 170 may be connected to the inlet side of the capillary 114. That is, the bypass pipe 170 may be connected between the temperature sensor 113 and the capillary 1140 to discharge the chemical liquid or the replacement liquid from the concentration measuring unit 112 to the outside of the concentration measuring unit 110.

In general, since the capillary 114 has a pipe shape having a relatively small diameter to remove bubbles from the chemical liquid, the flow rate of the chemical liquid or the replacement liquid discharged from the capillary 1140 may be limited. Therefore, when replacing the chemical solution to measure the concentration in the concentration measuring unit 110, or circulating the replacement to correct the concentration measuring unit 110, discharge the entire chemical or the replacement liquid through the capillary 1140 If you do not have to spend a lot of time. However, by using a bypass (By-Pass, Bypass) a portion of the chemical liquid or the replacement liquid through the bypass pipe 170, the time to replace the chemical liquid supplied from the first measuring unit or the second measuring unit or the concentration measurement using the replacement liquid The time required for the correction of the unit 110 can be shortened.

Referring to the operation of the chemical solution concentration measuring apparatus according to an embodiment of the present invention configured as described above are as follows.

Referring back to FIG. 3, first, the chemical liquid may be supplied from a predetermined position of the chemical liquid tank 20 through the first measuring unit, and the chemical liquid may be sent to the cooler 130 via the first supply pipe 151 of the chemical liquid supply pipe 150. . At this time, the 4-way valve 140 installed in the chemical liquid supply pipe 150 opens the first supply pipe 151 connected to the first measurement unit, and the second supply pipe 152 and the substitution liquid supply unit ( The third supply pipe 153 connected to the 120 may be blocked. The chemical liquid cooled to a predetermined temperature in the cooler 130 is supplied to the concentration measuring unit 110, and after measuring the concentration of the chemical liquid in the concentration measuring unit 110, the chemical liquid discharge pipe 160 and the bypass pipe 170 Can be discharged to the outside. The chemical liquid discharged from the chemical liquid concentration measuring apparatus 100 may be recovered and reused or discharged to the outside of the substrate processing apparatus 1.

Next, before the chemical solution is supplied through the second measurement unit, the concentration solution 110 receives the substitution solution from the substitution solution supply unit 120 to correct the concentration measurement unit 110, and then passes through the second supply pipe 152 to measure the concentration measurement unit 110. The chemical liquid previously supplied from the first measuring unit may be discharged. In this case, the 4-way valve 140 installed in the chemical liquid supply pipe 150 opens the third supply pipe 153 connected to the substitution liquid supply part 120, and the first supply pipe 151 and the second supply part connected to the first measurement part. The second supply pipe 152 connected to the measurement unit may be blocked.

Finally, the chemical liquid is supplied from the predetermined position of the chemical liquid tank 20 through the second measuring unit and supplied to the concentration measuring unit 110 via the second supply pipe 152 of the chemical liquid supply pipe 150 to perform the above process. Can be. At this time, the 4-way valve 140 installed in the chemical liquid supply pipe 150 opens the second supply pipe 152 connected to the second measurement part, and the first supply pipe 151 and the substitution liquid supply part ( The third supply pipe 153 connected to the 120 may be blocked.

In the present embodiment, the substrate G is for manufacturing a flat panel display (FPD) and is a rectangular flat plate, and the flat panel display is a liquid crystal display (LCD), a plasma display (PDP), or a vacuum fluoride (VFD). Display), FED (Field Emission Display), or ELD (Electro Luminescence Display). Alternatively, the substrate G may be a wafer used for manufacturing a semiconductor chip.

Those skilled in the art will appreciate that the present invention can be embodied in other specific forms without changing the technical spirit or essential features of the present invention. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the scope of the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and the equivalent concept are included in the scope of the present invention. Should be interpreted.

1 is a view schematically showing a structure of a general substrate processing apparatus.

FIG. 2 is a diagram illustrating an example in which two chemical liquid tanks are provided in the substrate processing apparatus of FIG. 1.

3 is a view schematically showing the structure of a chemical liquid concentration measuring apparatus according to an embodiment of the present invention.

4 is a view showing an example in which the chemical liquid concentration measuring apparatus according to an embodiment of the present invention is connected to the chemical liquid tank.

5 is a view schematically showing the structure of the concentration measuring unit in the chemical liquid concentration measuring apparatus according to an embodiment of the present invention.

(Explanation of symbols for the main parts of the drawing)

1: substrate processing apparatus G: substrate

10: substrate processing unit 20, 21, 22: chemical liquid tank

30: chemical supply pump 41, 42, 43: piping

100: chemical liquid concentration measuring unit 110: concentration measuring unit

120: replacement liquid supply unit 150: chemical liquid supply pipe

160: bypass piping 170: chemical liquid discharge pipe

Claims (6)

A concentration measuring unit which receives the chemical liquid from the chemical liquid tank storing the chemical liquid and measures the concentration of the chemical liquid; A substitution solution supply unit for supplying a substitution solution for discharging the measured chemical liquid from the concentration measurement unit to the concentration measurement unit; A chemical liquid supply pipe for supplying the chemical liquid or the substitution liquid to the concentration measuring unit; A bypass pipe which bypasses a part of the chemical liquid or the substitution liquid from the concentration measuring unit and discharges it to the outside; And And a chemical liquid discharge pipe discharging the chemical liquid or the replacement liquid discharged from the concentration measuring unit to the outside, The concentration measuring unit is connected to the chemical liquid discharge pipe, and includes a capillary (Capillary) for providing a passage for discharging the chemical liquid or the replacement liquid to the outside, The bypass pipe is connected to the capillary inlet side to bypass the chemical liquid or a part of the replacement liquid to be discharged to the outside, The bypass pipe is a chemical solution concentration measuring device having a larger diameter than the capillary. The method of claim 1, The concentration measuring unit, A bubble removing unit which receives the chemical liquid and removes bubbles contained in the chemical liquid; A concentration meter which detects the amount of light from the chemical liquid and measures the concentration of the chemical liquid; And The chemical liquid concentration measuring device further comprises a temperature sensor for measuring the temperature of the chemical liquid. The method of claim 1, The chemical liquid tank is connected to a concentration control unit for receiving a concentration value measured by the concentration measuring unit to control the concentration of the chemical liquid stored in the chemical liquid tank connected. The method of claim 3, wherein The concentration measuring unit measures a concentration of the chemical liquid on a circulation pipe for circulating the chemical liquid discharged from the concentration controller to the chemical liquid tank, or on a supply pipe for supplying the chemical liquid from the chemical liquid tank to a substrate processing unit. . The method of claim 1, The chemical liquid supply pipe is provided with a 4-WAY valve for selectively supplying the chemical liquid or the replacement liquid to the concentration measuring unit. The method of claim 1, The chemical liquid supply pipe is provided with a cooler for lowering the chemical liquid to a temperature usable by the concentration measuring unit.

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