JP2012178424A - Etchant concentration management apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an etchant concentration management apparatus in which, when performing etching treatment by supplying an etchant to a wafer while circulating the etchant in a manufacturing process of a solar cell panel, concentration of a specific component in the etchant is measured and corrected to an accurate measurement, and the concentration of the etchant is managed by supplementing a proper quantity of the specific component on the basis of the corrected measurement.SOLUTION: A part of an etchant 34 is extracted as a sampling liquid in the middle of a circulation route and introduced to a conductivity meter 58 and a pH meter 60, the concentration of hydrochloric acid in the sampling liquid is measured by the conductivity meter 58 at all the time and the concentration of hydrochloric acid is determined. Each time a predetermined time is elapsed for etching treatment or etching treatment is completely performed on a predetermined number of wafers W, on the other hand, the accurate concentration of hydrochloric acid in the sampling liquid is measured by the pH meter 60, the concentration of hydrochloric acid is determined, the measurement by the conductivity meter 58 is corrected with a measurement by the pH meter 60, and a suitable supplemental quantity of hydrochloric acid corresponding to the corrected value is supplemented to the etchant 34.

Description

  The present invention relates to an etching solution concentration management apparatus that performs concentration management while measuring the concentration of an etching solution that is used while being circulated when performing etching processing on a substrate in a solar cell panel manufacturing process.

  When a metal film formed on a substrate, for example, a zinc oxide (ZnO) film, is etched in a solar cell panel manufacturing process, a mixed solution containing an acid such as hydrochloric acid (HCl) is generally used as an etchant. Used and supplied to the substrate while circulating the etching solution. Thus, since the etching solution is used while being circulated, the composition of the etching solution gradually changes as the number of processed substrates increases, and the concentration of hydrochloric acid decreases. As the concentration of hydrochloric acid decreases, the etching characteristics become unstable. For this reason, it is necessary to measure the hydrochloric acid concentration in the etching solution, and to control the concentration by adding hydrochloric acid to the etching solution when the hydrochloric acid concentration falls below a predetermined concentration. The hydrochloric acid concentration in the etching solution is measured using a pH meter, a conductivity meter, or chromatography, or by potentiometric titration (see, for example, Patent Document 1, page 5, FIG. 1).

JP 2002-334865 A

  The etching solution used in circulation in the etching process of the substrate contains a zinc oxide component ionized and eluted along with the etching of the zinc oxide film, and the content concentration of the zinc oxide component also changes. Therefore, when measuring the hydrochloric acid concentration in the etching solution using a conductivity meter, the zinc oxide component ionized from the substrate and eluted in the etching solution affects the conductivity, and the hydrochloric acid concentration in the etching solution Cannot be measured accurately. Here, in the case of etching processing of a substrate for other uses other than the solar cell panel, even a measured value deviated to some extent from the true concentration has not been regarded as a problem, but the substrate in the solar cell panel manufacturing process In the case of the etching solution used in the etching process, an etching solution having a low hydrochloric acid concentration is used. Therefore, stricter concentration control is required compared to the etching processing of the substrate for other uses, and accurate concentration measurement is required. There is a problem such as.

  In the case of measurement using a pH meter, accurate measurement results can be obtained, but neutralization is performed by adding potassium chloride (KCl) or sodium hydroxide (NaOH) to the sampled etching solution. Therefore, there is a problem that the sampled etching solution needs to be always drained, leading to an increase in the consumption of the etching solution. This problem of increased consumption of the etching solution is unavoidable even in the case of measurement by potentiometric titration. Furthermore, in the case of measurement by potentiometric titration, there is a problem that the time required for concentration measurement is long, and expensive measuring equipment There is a problem that the cost increases due to the introduction. The problem of the length of the measurement time and the cost increase is the same in the case of measurement by chromatography.

  The present invention has been made in view of the circumstances as described above. In the manufacturing process of the solar cell panel, the substrate is supplied by circulating the etching solution to each substrate while sequentially transporting the substrates one by one. In the etching process, the concentration of the specific component of the etching solution is measured and corrected to an accurate measurement value, and the appropriate amount of the specific component is replenished based on the corrected measurement value to control the concentration of the etching solution. An object of the present invention is to provide a concentration management device capable of performing the above.

  In the manufacturing process of the solar cell panel, the invention according to claim 1 is a specific component of the etching solution when etching the substrate by supplying the substrate with the etching solution being circulated while sequentially transferring the substrates one by one. In an etching solution concentration management apparatus that performs concentration management while measuring the concentration of the etching solution, an etching solution supply means that includes an etching solution circulation path and supplies the etching solution to the substrate through the circulation path, and an etching solution circulation path Extraction means for extracting a part of the etching solution as a sampling solution on the way, and a first measurement for obtaining a first concentration of the specific component by constantly measuring the concentration of the specific component of the sampling solution taken out by the extraction means And measuring the concentration of the characteristic component of the sampling liquid taken out by the extraction means A second measuring means for obtaining a second concentration of the specific component and draining the measured sampling liquid; a specific component replenishing means for replenishing the specific component to the etching liquid supplying means; and the second measuring means The extraction unit is controlled to intermittently execute sampling liquid measurement at a predetermined frequency, the first concentration is corrected by the second concentration to obtain a correction value of the concentration of the specific component, and the correction Control means for controlling the specific component replenishing means so as to replenish the etching solution supply means with the replenishing amount of the specific component determined in advance corresponding to the value.

  According to a second aspect of the present invention, in the etching solution concentration management apparatus according to the first aspect, the control unit performs the measurement by the second measurement unit every time a predetermined time elapses in the etching process on the substrate or a predetermined number of sheets. The extraction means is controlled to be executed each time the substrate etching process is completed.

  According to a third aspect of the present invention, in the etching solution concentration management apparatus according to the first or second aspect, the first measurement unit includes a conductivity meter, and the second measurement unit includes a pH meter. Features.

  According to a fourth aspect of the present invention, in the etching solution concentration management apparatus according to any one of the first to third aspects, the etching solution is circulated in the etching solution circulation path while the substrate is transported therein. A processing tank, an etching liquid recovery pipe connected to the processing tank, an etching liquid recovery tank connected to the recovery pipe, an etching liquid supply pipe connected to the recovery tank, and And a plurality of discharge nozzles provided in the processing tank and connected to the etching solution supply pipe.

  According to a fifth aspect of the present invention, in the etching solution concentration management device according to the fourth aspect, the extraction means includes first and second sampling pipes branched from the etching liquid supply pipe, and the second sampling. And a valve inserted in the middle of the piping for piping, the first sampling piping is connected to the recovery tank and the conductivity meter is interposed in the middle thereof, and the second sampling piping Is characterized in that the pH meter is interposed downstream of the valve in the flow path direction.

  According to a sixth aspect of the present invention, in the etching solution concentration management apparatus according to the fourth aspect, the specific component replenishment means includes a specific component storage unit that stores the specific component having a predetermined concentration, and a predetermined amount of the specific component. Based on the control of the weighing tank to be stored and the control means, the specific component stored in the specific component storage unit is supplied and stored in a predetermined amount to the weighing tank, and further, the specific component stored in the weighing tank Specific component replenishing means for supplying a predetermined amount to the etching solution recovery pipe.

  The invention according to claim 7 is the etching solution concentration management apparatus according to any one of claims 1 to 6, wherein the specific component of the etching solution is hydrochloric acid, and the zinc oxide formed on the substrate The film is etched using the etching solution.

  In the etching solution concentration management device according to the first and seventh aspects of the invention, solar cell panel manufacturing requires more strict concentration management and requires accurate concentration measurement as compared with etching processing of substrates for other applications. Even in the case of the etching process of the substrate in the process, the concentration of the specific component in the etching solution can be measured with high accuracy, and an appropriate amount of the specific component can be replenished and used in the etching solution used for the etching process. Reduction of the etching solution can be achieved.

  In the etching solution concentration management device according to the second, fourth, and fifth aspects of the present invention, it is possible to reliably reduce the consumption of the etching solution.

  In the etching solution concentration management apparatus according to the third aspect of the present invention, the measurement can be performed quickly and at a lower cost than the measurement by potentiometric titration or the measurement by chromatography.

  In the etching solution concentration management apparatus according to the sixth aspect of the invention, an appropriate amount of the specific component can be easily replenished to the etching solution.

It is a schematic block diagram which shows typically the etching liquid density | concentration management apparatus which concerns on the best embodiment of this invention. FIG. 2 is a graph showing the relationship between the concentration of the zinc oxide component in the etching solution and the concentration of hydrochloric acid.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows the best embodiment of the present invention, and concentration management is performed while measuring the concentration of a specific component of an etching solution that is used while being circulated when performing etching processing on a substrate in a solar cell panel manufacturing process. 1 is a schematic diagram showing a schematic configuration of an etching solution concentration management device 1. FIG.

  The etching solution concentration management apparatus 1 includes an apparatus body 12 having an etching processing unit 10 and a concentration measurement / management unit 14 that measures and manages the concentration of hydrochloric acid in the etching solution. The etching processing unit 10 includes a processing tank 16 having a substrate carry-in port 18 and a substrate carry-out port 20, and a plurality of transport rollers 22 that support the substrate W loaded into the process tank 16 in a horizontal posture and transport the substrate W in the horizontal direction. , And a plurality of discharge nozzles 24 for supplying an etching solution to the surface of the substrate W transported by the transport roller 22.

  An etching solution recovery pipe 26 is connected to the bottom of the processing tank 16, and the recovery pipe 26 is connected to a recovery tank 28. An etching solution supply pipe 30 is connected to the bottom of the recovery tank 28 in communication therewith. An etching solution supply pump 32 is inserted in the supply pipe 30, and the supply pipe 30 is connected to the discharge nozzle 24 in a flow path. Then, the substrate processing unit 10 supplies an etching solution from the discharge nozzle 24 to the surface of the substrate W while sequentially transporting the substrates W one by one, and etches a predetermined amount of, for example, a zinc oxide film formed on the substrate W. . The etching solution supplied from the discharge nozzle 24 to the surface of the substrate W and flowing down from the top of the substrate W to the bottom of the processing bath 16 and the etching solution discharged from the discharge nozzle 24 and flowing down to the bottom of the processing bath 16 are processed in the processing bath. From the bottom of 16 through the recovery pipe 26, it flows into the recovery tank 28 and is recovered. The etching solution 34 stored in the collection tank 28 is supplied to the discharge nozzle 24 through the supply pipe 30 by the supply pump 32 and is discharged from the discharge nozzle 24. In this way, the etching solution is circulated through the circulation path constituted by the bottom of the processing tank 16, the recovery pipe 26, the recovery tank 28, the supply pipe 30 and the discharge nozzle 24, while in the processing tank 16. Supplied to the substrate W.

  Further, a hydrochloric acid replenishment pipe 36 is connected in the middle of the recovery pipe 26. A valve 38 is inserted in the hydrochloric acid supplementing pipe 36, and the hydrochloric acid supplementing pipe 36 is connected to the bottom of the weighing tank 40. The weighing tank 40 is designed to store a certain amount, for example, 500 ml of hydrochloric acid, and a hydrochloric acid supply pipe 42 is connected to the upper part of the weighing tank 40. The hydrochloric acid supply pipe 42 is connected to a hydrochloric acid supply pipe 44 through a three-way valve 66, and the hydrochloric acid supply pipe 44 flows into a hydrochloric acid supply unit 46 that stores hydrochloric acid of a predetermined concentration (wt% concentration). It is connected. Further, a hydrochloric acid supply pump 48 is inserted into the hydrochloric acid supply pipe 44, and an initial preparation pipe 50 connected to the recovery tank 28 is connected through a three-way valve 66.

  Then, the control signal is transmitted from the controller 64 to the hydrochloric acid supply pump 48 to operate the hydrochloric acid supply pump 48, and the hydrochloric acid supply pipe 44 branches to the initial preparation pipe 50 and the hydrochloric acid supply pipe 42. By transmitting a control signal to the inserted three-way valve 66 to connect the hydrochloric acid supply pipe 44 and the initial preparation pipe 50, a predetermined concentration of hydrochloric acid is led out from the hydrochloric acid supply unit 46 to the hydrochloric acid supply pipe 44. Then, it is supplied to the recovery tank 28 through the initial preparation pipe 50. In addition, by transmitting a control signal from the controller 64 to the three-way valve 66 to connect the hydrochloric acid supply pipe 44 and the hydrochloric acid supply pipe 42, hydrochloric acid is supplied to the weighing tank 40 through the hydrochloric acid supply pipe 42. A predetermined amount is stored. Then, when a predetermined amount of hydrochloric acid stored in the weighing tank 40 is opened by a control signal transmitted from the controller 64, a predetermined amount is supplied to the recovery tank 28 via the hydrochloric acid replenishment pipe 36 and the recovery pipe 26. It is a configuration to be supplied.

  A pure water supply pipe 52 connected to a pure water supply source (not shown) is connected to the treatment tank 16, and a pure water supply source is supplied from the pure water supply source by a control signal transmitted from the controller 64. Pure water is supplied into the treatment tank 16 through the pipe 52, and the supplied pure water flows from the bottom of the treatment tank 16 through the collection pipe 26 into the collection tank 28.

  The supply pipe 30 is provided with sampling pipes 54 and 56 branched in the middle thereof. The sampling pipe 54 is connected to the upper part of the collection tank 28, and a conductivity meter 58 is interposed in the middle thereof. A part of the etching liquid flowing in the supply pipe 30 from the recovery tank 28 toward the discharge nozzle 24 is taken out as a sampling liquid and introduced into the conductivity meter 58 via the sampling pipe 54. Thus, the hydrochloric acid concentration in the sampling solution is constantly measured by the conductivity meter 58, and the measured value is transmitted to the controller 64. After the measurement, the sampled liquid is collected in the collection tank 28 through the sampling pipe 54 and then led out to the supply pipe 30 for effective use. On the other hand, a pH meter 60 is interposed in the sampling pipe 56, and a valve 62 is inserted in the middle thereof. The valve 62 is transmitted from the controller 64 intermittently at a predetermined frequency, that is, every time a predetermined number of, for example, 10 substrates W are etched, or every time a predetermined time, for example, 30 minutes elapses. It is opened for a certain time by the control signal. Due to the intermittent opening of the valve 62, a part of the etching solution flowing in the supply pipe 30 from the recovery tank 28 toward the nozzle 24 is taken out as a sampling solution and introduced into the pH meter 60 through the sampling pipe 56. Is done. In this way, the hydrochloric acid concentration in the etching solution 34 is measured by the pH meter 60, and the measured value is transmitted to the controller 64. The measured sampling liquid is drained (drained) through the sampling pipe 56.

  When etching the substrate W by the etching solution concentration management apparatus 1 having the above-described configuration, first, pure water passes from the pure water supply source through the pure water supply pipe 52 in accordance with a control signal from the controller 64. Is supplied into the processing tank 16, and flows down from the bottom of the processing tank 16 into the recovery tank 28 through the recovery pipe 26. In parallel with the pure water supply, the control signal transmitted from the controller 64 to the hydrochloric acid supply pump 48 and the three-way valve 66 activates the hydrochloric acid supply pump 48 and causes the hydrochloric acid supply pipe 44 and the initial preparation pipe 50 to be connected. Communicate. As a result, a predetermined concentration of hydrochloric acid is led out from the supply unit 46 to the hydrochloric acid supply pipe 44 and supplied to the recovery tank 28 through the initial preparation pipe 50.

  Thereafter, when pure water and hydrochloric acid are prepared in the recovery tank 28 after the preset time has elapsed and the etching solution 34 containing hydrochloric acid having a predetermined concentration is generated, a control signal is transmitted from the controller 64 to the pure water supply source. Then, the supply of pure water is stopped and a control signal is transmitted to the three-way valve 66 to switch the flow path of the three-way valve 66. Then, the hydrochloric acid supply pipe 44 and the hydrochloric acid supply pipe 42 communicate with each other, and the hydrochloric acid stored in the hydrochloric acid supply unit 46 is supplied to the weighing tank 40 through the hydrochloric acid supply pipe 44 and the hydrochloric acid supply pipe 42. Stored. The weighing tank 40 is provided with a liquid level sensor (not shown), and transmits a signal to the controller 64 when the amount of hydrochloric acid stored reaches a certain level. Upon receiving this signal, the controller 64 transmits a control signal to the hydrochloric acid supply pump 48 to stop its operation and stop the supply of hydrochloric acid. Then, a control signal is transmitted from the controller 64 to the etchant supply pump 32 to operate the etchant supply pump 32, and the etchant 34 stored in the recovery tank 28 passes through the supply pipe 30 to the discharge nozzle 24. Supplied. When the discharge of the etching liquid 34 from the discharge nozzle 24 is started, a part of the etching liquid flowing in the supply pipe 30 is taken out as a sampling liquid and introduced into the conductivity meter 58 via the sampling pipe 54 at the same time. Thus, measurement of the hydrochloric acid concentration in the sampling solution by the conductivity meter 58 is started. Thereafter, the supply of the etching solution to the circulation path constituted by the bottom of the processing tank 16, the recovery pipe 26, the recovery tank 28, the supply pipe 30 and the discharge nozzle 24 is continued for a predetermined time (idling time). During this idling time, a change in hydrochloric acid concentration such as an increase in hydrochloric acid concentration caused by evaporation of water in the etching solution 34 is monitored by measurement with the conductivity meter 58.

  After a predetermined time has elapsed (after a predetermined idling time has elapsed), the substrates W are sequentially transferred one by one from the substrate carry-in port 18 into the processing tank 16 and are transferred from the discharge nozzle 24 to the surface of the substrate W transferred by the transfer roller 22. 34 is supplied, for example, a predetermined amount of a zinc oxide film formed on the substrate W is etched. An etching solution 34 supplied from the discharge nozzle 24 to the surface of the substrate W and flowing down from the top of the substrate W to the bottom of the processing bath 16 and an etching solution 34 discharged from the discharge nozzle 24 and flowing down to the bottom of the processing bath 16 are It flows from the bottom of the processing tank 16 through the recovery pipe 26 into the recovery tank 28 and is recovered. The etching solution 34 stored in the collection tank 28 is supplied to the discharge nozzle 24 through the supply pipe 30 by the supply pump 32 and is discharged from the discharge nozzle 24. In this way, the etching solution 34 is supplied to the substrate W in the processing tank 16 while circulating through the bottom of the processing tank 16, the recovery pipe 26, the recovery tank 28, the supply pipe 30 and the discharge nozzle 24. The The substrates W after the etching process are sequentially carried out one by one from the substrate carry-out port 20.

  Simultaneously with the start of the supply of the etching solution 34 to the discharge nozzle 24 by the operation of the etching solution supply pump 32, the concentration of hydrochloric acid (HCl) in the sampling solution of the etching solution 34 flowing in the sampling pipe 54 is measured by the conductivity meter 58. Is started. On the other hand, a control signal is intermittently transmitted from the controller 64 to the valve 62 every time a predetermined number of substrates W are etched, for example, 10 times, or every time a predetermined time, for example, 30 minutes elapses. The valve 62 is opened for a short time, for example, 10 seconds, and the hydrochloric acid concentration in the sampling solution introduced into the pH meter 60 via the sampling pipe 56 is measured by the pH meter 60. The measured value by the pH meter 60 is transmitted to the controller 64.

  Here, as described above, the etching solution 34 that is circulated includes a zinc oxide (ZnO) component that is ionized and eluted as the zinc oxide film is etched. When the hydrochloric acid concentration in the etching solution 34 is measured using the conductivity meter 58, the zinc oxide component affects the conductivity, so that the hydrochloric acid concentration in the etching solution 34 can be accurately measured. Can not. On the other hand, in the case of measurement using a pH meter, an accurate measurement result can be obtained.

  FIG. 2 is a graph showing the relationship between the concentration of the zinc oxide component in the etching solution 34 and the concentration of hydrochloric acid. The vertical axis shows the concentration (wt%) of hydrochloric acid in the etching solution 34, and the horizontal axis shows zinc oxide. The component concentration (ppm) is shown. In FIG. 2, the straight line shows the measured value by the conductivity meter, and the black circle plot shows the measured value by the pH meter. As is apparent from FIG. 2, as the zinc oxide component concentration (ppm) in the etching solution 34 increases with the progress of the etching process, the measured value and pH of the hydrochloric acid concentration (wt%) measured by the conductivity meter 58. There is a gradual divergence from the value measured by the total 60.

  Therefore, the controller 64 intermittently transmits the measurement value constantly transmitted from the conductivity meter 58 at a predetermined frequency, that is, every time a predetermined etching process time elapses or every time the etching process of the substrate W is completed by a predetermined number. The correct concentration value is obtained by correcting the measured value transmitted from the pH meter 60.

  Table 1 shows numerical values corresponding to the graph of FIG. 2 and shows an example of the contents of this correction. In Table 1, the numerical values in the column relating to the conductivity meter are measured values extracted about every 200 ppm with respect to the zinc oxide concentration from the hydrochloric acid concentration values in the etching solution 34 obtained by constantly measuring, and are related to the pH meter. The numerical value in the column is the measured value by the pH meter measured at the same time when the measured value by the conductivity meter thus extracted is obtained. For example, when the measured value of the hydrochloric acid concentration by the conductivity meter 58 on the sixth line in Table 1 is 0.4780 wt%, the measured value by the pH meter 60 indicates 0.4589 wt%, and the former measured value is the latter Correct to the measured value.

  In the controller 64, data on the replenishment amount of hydrochloric acid to be replenished to the recovery tank 28 corresponding to the corrected accurate concentration value is stored in advance. Then, by sending a control signal to the valve 38 and opening the valve 38, a replenishment amount of hydrochloric acid set in advance from the weighing tank 40 is supplied to the recovery tank 28 via the hydrochloric acid replenishment pipe 36 and the recovery pipe 26. refill. When the amount of hydrochloric acid stored in the weighing tank 40 decreases to a predetermined level, a signal is transmitted from the liquid level sensor to the controller 64. Upon receiving this signal, the controller 64 transmits a control signal to the hydrochloric acid supply pump 48 to operate the hydrochloric acid supply pump 48 and transmits a control signal to the three-way valve 66. When the flow path is switched by the three-way valve 66, hydrochloric acid is supplied from the hydrochloric acid supply unit 46 to the weighing tank 40 through the hydrochloric acid supply pipe 44 and the hydrochloric acid supply pipe 42. Thus, a predetermined amount of hydrochloric acid is stored in the weighing tank 40.

  As described above, in the etching solution concentration management device 1 according to the present embodiment, the concentration value of hydrochloric acid in the etching solution 34 constantly measured by the conductivity meter 58 is intermittently measured at a predetermined frequency by the pH meter 60. That is, every time a predetermined etching processing time elapses or every predetermined number of etching processing of the substrate W, an accurate measurement value is obtained by correcting with a concentration value measured in a short time, and an appropriate amount of hydrochloric acid is calculated based on this accurate correction value. It is easy to replenish. Therefore, unlike the case where the hydrochloric acid concentration in the etching solution is measured using only the conductivity meter, the zinc oxide component eluted and contained in the etching solution affects the conductivity, and the measured value by the conductivity meter is actually Even if it deviates from the concentration value, it is possible to measure the concentration with high accuracy by correcting it to an accurate concentration value obtained by intermittent measurement with a pH meter.

  Unlike the case where the hydrochloric acid concentration in the etching solution is measured using only the pH meter, the sampling solution taken out from the etching solution 34 does not need to be drained all the time, and only needs to be drained during intermittent measurement. . For this reason, the consumption of the etching solution can be reduced.

  The best embodiment of the present invention has been described above. However, the present invention is not limited to this, and various modifications can be made.

  For example, in the above-described embodiment, the concentration of the hydrochloric acid component in the etching solution is an object of concentration measurement, but the concentration of other components, for example, an alkaline component such as KOH, depending on the components of the etching solution used depending on the object of etching removal. It is good also as a measuring object. The substrate W to be etched is horizontally transported in the processing tank 16, and the etching solution is transported in a posture inclined at a predetermined angle with respect to the horizontal plane in a direction orthogonal to the substrate transport direction, while the etching solution is transferred to the surface of the substrate. You may apply to what performs an etching process by discharging with respect to.

  Furthermore, in the above-described embodiment, for the purpose of promoting the degree of mixing in the generation of the etching solution 34, the pure water supply pipe 52 is connected to the treatment tank 16 and supplied from the pure water supply pipe 52 into the treatment tank 16. The pure water is configured to flow from the bottom of the treatment tank 16 through the recovery pipe 26 into the recovery tank 28, and the hydrochloric acid replenishment pipe 36 is connected in the middle of the recovery pipe 26 and connected to the hydrochloric acid. Although the hydrochloric acid is replenished to the recovery tank 28 from the replenishment pipe 36 through the recovery pipe 26, the pure water supply pipe 52 and the hydrochloric acid replenishment pipe 36 are directly connected to the recovery tank 28. Pure water and hydrochloric acid may be directly supplied to the recovery tank 28.

DESCRIPTION OF SYMBOLS 1 Etching-solution density | concentration management apparatus 10 Etching process part 12 Apparatus main body 14 Concentration measurement and management part 16 Processing tank 18 Substrate carry-in port 20 Substrate carry-out port 22 Conveyance roller 24 Discharge nozzle 26 Collection pipe 28 Collection tank 30 Supply pipe 30
32 Etching solution supply pump 34 Etching solution 36 Hydrochloric acid replenishment piping 38, 62 Valve 40 Weighing tank 42 Hydrochloric acid replenishing piping 44 Hydrochloric acid supply piping 46 Hydrochloric acid supply unit 48 Hydrochloric acid supply pump 50 Initial preparation piping 52 Pure water supply piping 54, 56 Sampling piping 58 Conductivity meter 60 pH meter 64 Controller 66 Three-way valve W Substrate

Claims (7)

Concentration management while measuring the concentration of specific components of the etchant when etching the substrate by supplying the substrate with the etchant circulating while supplying the substrate one by one in the solar cell panel manufacturing process. In the etching solution concentration management device that performs
An etchant supply means for supplying an etchant to the substrate through the circulation path, the etchant supply means having an etchant circulation path;
Extraction means for taking out a part of the etching solution as a sampling solution in the middle of the circulation path of the etching solution;
First measuring means for constantly measuring the concentration of the specific component of the sampling liquid taken out by the extracting means to obtain the first concentration of the specific component;
A second measuring means for measuring the concentration of the characteristic component of the sampling liquid taken out by the extracting means to obtain a second concentration of the specific component and draining the measured sampling liquid;
Specific component replenishing means for replenishing the etching solution supply means with the specific component;
The extraction means is controlled to intermittently execute the measurement of the sampling solution by the second measurement means at a predetermined frequency, and the first concentration is corrected by the second concentration to adjust the concentration of the specific component. Control means for obtaining a correction value and controlling the specific component replenishing means so as to replenish the etching solution supplying means with a predetermined replenishment amount corresponding to the correction value;
An etching solution concentration management apparatus comprising: In the etching solution concentration management apparatus according to claim 1,
The control means controls the extraction means so that the measurement by the second measuring means is performed every time a predetermined time elapses for etching the substrate or every time a predetermined number of the substrates are etched. Etching solution concentration management device characterized by the above. In the etching solution concentration management device according to claim 1 or 2,
The etching solution concentration management apparatus, wherein the first measuring unit includes a conductivity meter, and the second measuring unit includes a pH meter. In the etching solution concentration management device according to any one of claims 1 to 3,
The etching liquid circulation path includes a processing tank in which an etching process is performed while the substrate is transported therein, an etching liquid recovery pipe connected to the processing tank, and an etching pipe connected to the recovery pipe. A liquid recovery tank, an etchant supply pipe connected to the recovery tank, and a plurality of discharge nozzles provided in the processing tank and connected to the etchant supply pipe. Etching concentration control device. In the etching solution concentration management device according to claim 4,
The extraction means includes first and second sampling pipes branched from the etching solution supply pipe, and a valve interposed in the middle of the second sampling pipe, and the first sampling pipe includes: The conductivity meter is interposed in the middle of the flow path connected to the recovery tank, and the pH meter is interposed downstream of the valve in the second sampling pipe with respect to the flow path direction. Etching concentration control device. In the etching solution concentration management device according to claim 4,
The specific component replenishing means is stored in the specific component storage unit based on the control of the specific component storage unit for storing the specific component having a predetermined concentration, the weighing tank for storing the specific component in a predetermined amount, and the control means. A specific component replenishing means for supplying a predetermined amount of the specific component to the weighing tank and storing the specific component and supplying the specific component stored in the weighing tank to the etching solution recovery pipe. Etching solution concentration management device characterized by the above. In the etching solution concentration management device according to any one of claims 1 to 6,
An etching solution concentration management apparatus, wherein the specific component of the etching solution is hydrochloric acid, and a zinc oxide film formed on the substrate is etched using the etching solution.

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