JP2003248326A - Developer supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer supply system capable of highly accurately detecting the alkali concentration and the dissolved resin concentration in developer recovered from the developing process of a liquid crystal substrate and a printed board, and capable of supplying the developer of more accurately adjusted concentration to the developing process. <P>SOLUTION: The developer supply system is provided with a supply tank (1) for storing the developer to be supplied, a recovered liquid supply mechanism (2) for feeding the used developer to the supply tank (1), a raw liquid supply mechanism (3) for feeding a new developer raw liquid to the supply tank, and a specific concentration meter (5) for detecting the alkali concentration and the resin concentration in the used developer at a fixed temperature based on an ultrasonic wave transmission speed and an electromagnetic conductivity. The feeding of the developer raw liquid by the raw liquid supply mechanism (3) is controlled based on the concentration detected by the concentration meter (5). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer supply device, and more specifically, it controls the alkali concentration and the dissolved resin concentration of a developer recovered from the development process of a liquid crystal substrate or a printed circuit board. The present invention relates to a developing solution supply device that supplies a developing solution readjusted to a constant concentration to a developing process.

[0002]

2. Description of the Related Art An alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) is used as a developing solution for developing a photoresist in the process of manufacturing a liquid crystal substrate or a printed circuit board. These developers are
Due to the increase in the substrate size and the progress of the process, it is used in large quantities, and it is recycled and supplied to the development process from the viewpoint of cost reduction.

On the other hand, the developer as described above has a reduced alkali concentration due to a reaction with an acid in the resin and a reaction with carbon dioxide gas or oxygen in the air during repeated use, and also during development processing. Since the resin concentration rises due to the dissolution of the resist resin in the above, in order to secure the dimensional accuracy of the resist pattern and the film thickness accuracy of the unexposed area, the alkali concentration of the developer should be controlled as constant as possible and It is necessary to manage below a certain level.

Regarding the concentration control of the developing solution, for example, Japanese Patent No. 2561578 discloses an apparatus for controlling an alkaline developing solution used for developing a photoresist, in which the developing solution is circulated and supplied to the developing apparatus. In addition, a "developing solution management device" is described in which both the alkali concentration of the circulating developing solution and the concentration of dissolved resin in the developing solution are simultaneously controlled to prevent deterioration of developing performance.

In the above developing solution management apparatus, the concentration of dissolved resin in the developing solution is detected by an absorptiometer, the alkali concentration of the developing solution is detected by a conductivity meter, and the liquid level of the developing solution in the apparatus is further detected. The level is detected by a liquid level meter, and the developing solution in the apparatus is discharged and the alkaline developing stock solution and pure water are replenished so that the dissolved resin concentration, alkali concentration and liquid level are constant. It is designed to replenish a new developer prepared in advance.

The above-mentioned developing solution management apparatus uses a batch method for measuring the alkali concentration and the dissolved resin concentration and replacing the new developing solution with a new developing solution. It is intended to improve the dimensional accuracy of the resist pattern to be developed and the film thickness accuracy of the unexposed portion by measuring the values in real time and controlling them continuously, and to prevent the deterioration of the operation rate due to liquid exchange. Is. For example, the TMAH concentration used as a developer is usually adjusted to 2.38% by weight.
The concentration is controlled within the range of 2.38 ± 0.02% by weight.

[0007]

By the way, in the developing process of a liquid crystal substrate or a printed circuit board, a higher quality developing solution is desired in order to further improve the pattern accuracy and the film thickness accuracy and further improve the product yield. There is. However, in the conventional developer management device as described above, it is difficult to adjust the concentration of the developer with higher accuracy because of the problem of the measurement accuracy with respect to the concentration of the dissolved resin and the alkali concentration in the developer.

That is, in the detection of the concentration of the dissolved resin in the developing solution by an absorptiometer, there are many absorption wavelength peaks of the dissolved resin in the developing solution in the wavelength range from ultraviolet light to visible light, and there is a change in the resin concentration. Since the peak values fluctuate and the absorption wavelength peaks overlap with each other as the resin concentration increases, the fact that the detection accuracy decreases cannot be avoided due to the problem of selection of the measurement wavelength. Therefore, it is difficult to further improve the control accuracy of the resin concentration in the developer, and when the resin concentration becomes high, it is difficult to increase the detection accuracy of the alkali concentration by the measurement by conductivity due to the problem of detection accuracy. However, it is difficult to further improve the control accuracy of the alkali concentration.

The present invention has been made in view of the above circumstances, and an object thereof is to control the alkali concentration and the dissolved resin concentration of a developer recovered from the development process of a liquid crystal substrate or a printed circuit board, and to maintain a constant concentration. A developer supply device that supplies the adjusted developer to the development process, which can detect the concentration of each component of the developer with higher accuracy and supplies the adjusted developer to the development process more accurately. An object of the present invention is to provide a developing solution supply device capable of supplying the developing solution.

[0010]

In order to solve the above problems, in the present invention, in detecting the alkali concentration and the dissolved resin concentration in the recovered developer, the temperature and each component concentration are uniquely determined and By using a multi-component densitometer that simultaneously measures ultrasonic wave propagation velocity and electromagnetic conductivity without fluctuations in measurement accuracy due to concentration fluctuations,
The alkali concentration and the resin concentration are detected with higher accuracy, and the developer concentration is controlled with higher accuracy.

That is, the gist of the present invention is a developer supply device for supplying a developer comprising an alkaline aqueous solution to a development process, and a supply tank for storing the developer to be supplied and a used developer recovered. And a stock solution supply mechanism for sending a used developer to the supply storage tank, a stock solution supply mechanism for sending a new developer stock solution to the supply storage tank, A concentration meter for detecting the alkali concentration and the resin concentration of the used developing solution at a constant temperature sent by the recovery solution supply mechanism is provided, and the concentration meter is the ultrasonic wave propagation speed in the developing solution and the electromagnetic conductivity of the developing solution. Is a multi-component densitometer that measures the rate and detects the alkali concentration and resin concentration based on the relationship between the ultrasonic wave propagation velocity and the electromagnetic conductivity at a predetermined temperature and a predetermined concentration, Te, based on the detected concentration by the concentration meter, lies in the supply system of the developing solution, characterized in that it is adapted to controllably feed liquid developer stock by the stock feed mechanism.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a developer supply apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a flow chart showing main components of a developer supply device according to the present invention. FIG. 2 is a graph in which the detection accuracy of the multi-component densitometer is confirmed in real time. In the following description of the embodiments, the developer supply device is abbreviated as “supply device”.

The supply device of the present invention is a device for supplying a developing solution comprising an alkaline aqueous solution to a developing process including a developing device such as a spin developer device used in the developing process, and the developing solution recovered from the developing process. It has a function of controlling the alkali concentration and the dissolved resin concentration of and also supplying the developing solution readjusted to a constant concentration to the developing process.

In the present invention, as the alkaline developing solution, an inorganic alkaline aqueous solution consisting of a single or a mixture of inorganic alkalis such as potassium hydroxide, sodium hydroxide, sodium phosphate and sodium silicate, or tetramethylammonium hydroxide is used. (TMAH), an organic alkaline aqueous solution such as trimethylmonoethanol ammonium hydroxide (choline), and the like.

As shown in FIG. 1, the supply device of the present invention stores a supply storage tank (1) for storing the developing solution to be supplied to the developing device (99) in the developing process and a temperature of the recovered used developing solution. A recovery liquid supply mechanism (2), which is provided with a temperature control means for constant adjustment and supplies the used developer to the supply storage tank (1);
Detects the alkali concentration and resin concentration of the used developer at a constant temperature sent by the stock solution supply mechanism (3) that sends new developer stock solution to the supply storage tank (1) and the recovery solution supply mechanism (2) And a densitometer (5) (hereinafter, referred to as “first densitometer”).

The supply storage tank (1) is a buffer tank for adjusting the concentration of the developing solution to a constant target value and supplying the developing solution with the adjusted concentration to the developing device (99) as required. , A container having an internal volume of about 100 to 2000 liters and having corrosion resistance. The supply storage tank (1) has a pump (71) and a circulation flow path (9) for adjusting and maintaining the concentration of the developer to be stored.
A developing solution stirring means consisting of 6) is provided. The stirring means by circulation as described above generates less particles and can reduce contamination of the developing solution as compared with a stirring device such as a screw installed in the tank. The developing solution stored in the supply storage tank (1) is supplied to the developing device (99) through the pump (12) and the flow path (97).

The recovery liquid supply mechanism (2) includes a recovery liquid storage tank (21) for temporarily storing the used developing solution, a pump (22) for supplying the stored used development solution to the supply storage tank (1) side, and a flow path. (91) and the like. The recovery liquid storage tank (21) is
For example, it is composed of a container having an internal volume of about 500 to 3000 liters and having corrosion resistance. Collected liquid storage tank (2
In 1), the used developing solution discharged from the developing device (99) may be directly received, or the used developing solution temporarily stored separately may be received.

The recovery liquid storage tank (21) is provided with a stirring means consisting of a pump (24) and a circulation flow path (92) in order to make the concentration of the used developing solution received uniform. The stirring means by circulation as described above can reduce the generation of particles and reduce the contamination of the developing solution, as in the case of the supply storage tank (1).

The pump (22) and the flow path (91) are, for example, the flow path (of the stock solution supply mechanism (3) described later that reaches the supply storage tank (1) through the mixer (4) and the flow path (94). 93)
Connected to. The temperature adjusting means of the recovery liquid supply mechanism (2) is provided for accurately measuring the concentration of the used developing solution by the first densitometer (5) described later, and for example, in the flow path (91). It is composed of a constant temperature bath (23) arranged on the way. That is, the collected used developing solution is adjusted to a constant temperature (for example, 25 ° C.) in the constant temperature tank (23) in the middle of the flow path (91), and then sent to the supply storage tank (1) side. Has been done. Although not shown, the recovery solution supply mechanism (2) is usually provided with a purge line for purging a part of the used development solution when the resin concentration of the recovered development solution is high. Furthermore, it may be possible to supply dilution water to the recovery liquid storage tank (21).

The used developer recovered from the developing device (99) has a reduced alkali concentration due to the reaction with the acid in the resist and the reaction with carbon dioxide gas and oxygen in the air, and also dissolves the resist resin. Since the resin concentration is increased by the above, the stock solution supply mechanism (3) is used in the supply device of the present invention.
By this, a new developing solution stock solution can be added to the used developing solution as needed.

The stock solution supply mechanism (3) supplies a stock solution stock solution (31) for storing a stock solution of high concentration, for example, a stock solution having a concentration of 20 to 25% by weight, and a stock solution stock solution stored to the supply tank (1) side. It mainly consists of a pump (32) and a flow path (93). The stock solution storage tank (31) is the recovery solution storage tank (2
Similar to 1), for example, it is constituted by a container having an internal volume of about 500 to 3000 liters and having corrosion resistance.
The flow path (93) is connected to the supply reservoir (1) via the mixer (4) and the flow path (94). The mixer (4) is a stirrer having a built-in fixed screw for mixing a new developing solution stock solution with the used developing solution sent by the flow path (91) of the recovery solution supply mechanism (2).

The supply storage tank (1), the recovery solution storage tank (21) and the stock solution storage tank (31) are protected by an inert gas such as nitrogen in order to prevent the developer solution or the developer solution stock solution from contacting with air. It is designed to be sealed. Further, in the supply device of the present invention, in order to keep the amount of liquid in the system constant, a mechanism for discharging the excess used developing solution to the outside of the system when the developing solution stock solution is supplied is provided at an appropriate position. Although not shown,
For example, the recovery liquid storage tank (21) is provided with a drain passage including a control valve or an overflow device.

The first densitometer (5) detects the concentration of the used developing solution at a constant temperature which is fed to the supply storage tank (1). It is arranged in the middle of the flow path (91). In the supply device of the present invention, a specific densitometer is used to detect the resin concentration and the alkali concentration with high accuracy without being affected by the fluctuation of the dissolved resin concentration in the used developer. In particular,
As the first densitometer (5), the ultrasonic wave propagation speed in the developing solution and the electromagnetic conductivity of the developing solution are measured, and the ultrasonic wave propagation speed and the electromagnetic conductivity at a predetermined temperature and a predetermined concentration are created. Based on the relationship (matrix) of
A multi-component densitometer that detects alkali concentration and resin concentration is used.

The above multi-component densitometer is a densitometer capable of simultaneously measuring the concentrations of two components of a three-component system solution in real time by measuring ultrasonic wave propagation velocity and electromagnetic conductivity in a solution at a constant temperature. is there. That is, the multi-component densitometer is based on the principle that, if the temperature of the solution is constant, the propagation velocity and electromagnetic conductivity of ultrasonic waves in the liquid are uniquely specified according to the concentration of each component. It mainly comprises an ultrasonic transducer, an ultrasonic transmitter, an electromagnetic conductivity converter, an electromagnetic conductivity transmitter and a microprocessor for performing a predetermined calculation.

In the multi-component densitometer, when applied to the concentration measurement of the developer as described above, the ultrasonic wave propagation velocity and the electromagnetic wave velocity previously measured under a constant temperature condition for each combination of alkali concentration and dissolved resin concentration are used. By preparing the relationship of conductivity as a matrix in advance, that is, by writing it in the microprocessor, the alkali concentration and the dissolved resin concentration can be accurately estimated and calculated from the measured values based on the matrix. As the multi-component densitometer as described above, a product name “FUD-1” manufactured by Fuji Kogyo Co., Ltd.
An ultrasonic multi-component densitometer for liquids known as “Model-51” can be preferably used.

The supply device of the present invention can control the liquid feed of the developing solution stock solution by the stock solution supply mechanism (3) based on the concentration detected by the first densitometer (5). Feeding of the developing solution stock solution is controlled by a controller (not shown) described later. As a result, the decrease in the alkali concentration and the increase in the resin concentration in the used developer can be complemented, the alkali concentration of the developer stored in the supply storage tank (1) can be constantly controlled, and the resin concentration can be constantly controlled to a certain level or less. .

By the way, in order to control the concentration of the developer supplied to the developing device (99) with higher accuracy, it is preferable to directly detect the concentration of the developer in the supply storage tank (1). Further, even when the dissolved resin concentration of the used developer sent by the recovery liquid supply mechanism (2) exceeds the allowable value, the stock solution supply mechanism (3 However, the alkali concentration in the supply storage tank (1) may exceed the target value depending on the supply amount of the developer solution.

Therefore, the supply apparatus of the present invention is provided with a dilution water supply mechanism for supplying the dilution water to the supply storage tank (1). Moreover, in order to finally finely adjust the alkali concentration of the developing solution in the supply storage tank (1), the second temperature adjusting means for adjusting the temperature of the developing solution in the supply storage tank (1) to be constant, and the supply storage tank (1). And a second densitometer (8) for detecting the alkali concentration and the resin concentration of the constant temperature developer. Then, in the supply device of the present invention, based on the concentration detected by the second densitometer (8), the stock solution supply mechanism (3) supplies the developer stock solution and the dilution water supply mechanism supplies the dilution water. Can be controlled by a control device described later.

As the above-mentioned dilution water supply mechanism, a pure water producing device (6) is usually used, and ultra pure water is supplied from the pure water producing device (6) to the supply tank (1) through the flow path (95). Is available. The second temperature adjusting means is
It is provided in order to measure the concentration of the developer more accurately, and for example, a circulation flow path (9
It is composed of a constant temperature bath (72) arranged in the middle of 6). That is, in the supply storage tank (1), the temperature of the developing solution is kept constant by temporarily retaining the developing solution during circulation in the constant temperature tank (72). Further, as the second densitometer (8), the same multi-component densitometer as the first densitometer (5) is used.

The supply control of the developing solution stock solution and the diluting water is based on the concentration detected by the second densitometer (8), and the supply amount of the developing solution stock solution from the stock solution supply mechanism (3) and the dilution water supply mechanism ( It is performed by cascade controlling the amount of dilution water supplied from the pure water producing device (6). In such control, for example, the so-called asymptotic method disclosed in "Method of diluting undiluted solution of acid or alkali and diluting apparatus" described in JP-A-10-180076 can be used.

Specifically, in the adjustment of the alkali concentration in the supply storage tank (1) using the above-described asymptotic method, the developer in the supply storage tank (1) in which the alkali concentration has decreased (or the alkali concentration has increased) is developed. When adding a high-concentration stock solution of the developing solution (or diluting water) to adjust the concentration to a predetermined level, the second concentration meter (8) measures the concentration of the developing solution and the concentration measuring step. Calculated based on the difference between the concentration value and the target concentration value, the shortage amount (or addition amount of dilution water) of the developing solution stock solution is calculated, and the calculated shortage amount (or addition amount) is calculated as 85
And 99%, preferably 92-98%, and a concentration step is performed until the measured concentration value falls within a preset target concentration threshold. Repeat the steps and preparation steps. This allows
The alkali concentration in the developer in the supply storage tank (1) can be controlled with higher accuracy.

Further, in a more preferable aspect of the present invention, in order to control the concentration of the developer in the supply storage tank (1) with higher accuracy, a constant temperature tank (7) as a second temperature adjusting means is used.
2) is provided with a temperature sensor (not shown) for detecting the temperature of the developing solution. And the second densitometer (8)
Has a function of performing a correction calculation based on the temperature of the developing solution detected by the temperature sensor when detecting the alkali concentration and the resin concentration in the supply storage tank (1).

That is, in the multi-component densitometer as described above, the ultrasonic wave propagation velocity and the electromagnetic conductivity obtained by measuring in advance for each combination of alkali concentration and dissolved resin concentration and under a plurality of temperature conditions. By preparing the relationship as a matrix in advance, the alkali concentration and the dissolved resin concentration of the developer in the supply storage tank (1) can be more accurately estimated and calculated based on the matrix and the detected actual temperature of the developer.

In the supply device of the present invention, in addition to the operation control of the entire device, the feeding of the developing solution undiluted solution based on the measurement of the first densitometer (5) as described above is controlled to control the second densitometer. (8)
Control device (not shown) having an arithmetic function for controlling the liquid supply of the developing solution and the liquid supply of the diluting water based on the measurement of
Is provided. Such a control device includes an input device that digitally converts a signal of each measuring device, an arithmetic processing device such as a program controller or a computer, and an output device that analog-converts a control signal from the arithmetic processing device.

In the supply device of the present invention, the used developer stored in the recovery liquid storage tank (21) of the recovery liquid supply mechanism (2) is heated to a constant temperature in the constant temperature tank (23), and then the flow path (9) is used.
1), liquid is sent to the supply storage tank (1) through the flow path (94). At that time, the alkali concentration and the resin concentration of the used developing solution are measured by the first densitometer (5) provided in the flow path (91). As a result, when the alkali concentration measured by the first densitometer (5) is lower than the reference value,
Alternatively, when the resin concentration exceeds the reference limit value, the stock solution storage tank (3) is passed through the flow path (93) and the flow path (94).
The concentrated high-concentration developer solution stored in 1) is sent to the supply storage tank (1).

In the case of supplying the undiluted solution of the developing solution, the flow path (91)
The used developing solution and the undiluted developing solution are mixed by the mixer (4) provided at the latter stage of the flow path (93). Furthermore, the developer stored in the supply storage tank (1) is pumped (7
Mixing is performed by a stirring means composed of 1) and a circulation channel (96) so as to obtain a more uniform concentration.

As described above, in the supply device of the present invention, the alkali concentration and the resin concentration of the used developer are set to the first value.
When measuring with the densitometer (5), the liquid temperature was set to a constant temperature, and as the first densitometer (5), the measured ultrasonic wave propagation velocity and electromagnetic conductivity, and a specific pre-made Since a multi-component densitometer that simultaneously detects both alkali concentration and resin concentration based on the relationship (matrix) is used, the alkali concentration and resin concentration of the used developer can be detected more accurately. In addition, the resin concentration of the developer in the supply storage tank (1) can be reliably controlled to be less than the allowable concentration, and the alkali concentration can be adjusted with high accuracy.

In the supply device of the present invention, the temperature of the developing solution is kept constant by the constant temperature tank (72) (second temperature adjusting means) attached to the supply storage tank (1), and the second The alkali concentration and resin concentration of the circulating developing solution, that is, the developing solution in the supply storage tank (1) are measured by the densitometer (8). As a result, when the resin concentration exceeds the allowable value, the pure water producing device (6) (dilution water supply mechanism) supplies the dilution water to the supply storage tank (1) through the flow path (95). When the alkali concentration measured by the second densitometer (8) is lower than the target value,
Similar to the above operation, the stock solution supply mechanism (3) supplies the high-concentration developer stock solution in the stock solution storage tank (31) to the supply storage tank (1), and when the alkali concentration is higher than the allowable value, Dilution water is supplied to the supply storage tank (1) by the water production device (6).

In the supply device of the present invention, as described above, the temperature of the developer in the supply storage tank (1) whose concentration has been once adjusted is set to a constant temperature, and then the first densitometer (5) is used. The second densitometer (8), which is a similar multi-component densitometer, again measures the alkali concentration and the resin concentration with high accuracy, and finely adjusts the alkali concentration and the resin concentration of the developer. Moreover, at that time, by the control device having a specific arithmetic function,
The supply amount of the developing solution stock solution or the diluting water is controlled based on the above-described asymptotic method for gradually approaching the target concentration. Therefore, the resin concentration of the developer in the supply storage tank (1) can be controlled more reliably below the allowable concentration, and the alkali concentration can be adjusted with higher accuracy. As a result, according to the supply device of the present invention, the developing device (9
9) can be supplied.

Incidentally, in the feeder of the present invention, in order to confirm the detection accuracy of the multi-component densitometer used as the densitometer, an aqueous solution T of TMAH recovered as a used developer is confirmed.
When the MAH concentration was continuously measured in the flow channel (91), it was 2.376 (average value) as shown in the graph of FIG.
It was ± 0.005% by weight, and the TMAH concentration could be detected with high accuracy. The dissolved resin concentration set as the control target value was 1000 ppm. Then, in the supply device of the present invention, in the supply storage tank (1), the TMAH concentration of the final developing solution could be adjusted to 2.380 ± 0.005 wt% and the resin concentration to 1000 ± 150 ppm.

[0041]

As described above, according to the developing solution supply apparatus of the present invention, the developing solution is obtained by directly measuring the ultrasonic wave propagation velocity and the electromagnetic conductivity using a specific multi-component densitometer. Since the concentrations of the respective components can be detected with high accuracy, it is possible to supply a high-quality developer whose concentration has been adjusted with higher accuracy to the development process.

[Brief description of drawings]

FIG. 1 is a flow chart showing main components of a developer supply device according to the present invention.

FIG. 2 is a graph in which the detection accuracy of a multi-component densitometer is confirmed in real time.

[Explanation of symbols]

1: Supply tank 2: Recovery liquid supply mechanism 21: Collected liquid storage tank 23: Constant temperature bath (temperature control means) 3: Stock solution supply mechanism 31: Stock solution storage tank 32: Pump 4: Mixer 5: Densitometer (first densitometer) 6: Pure water production device (dilution water supply mechanism) 72: Constant temperature bath (second temperature adjusting means) 8: Second densitometer 91: flow path 92: Circulation flow path 93: flow path 94: flow path 95: flow path 96: Circulation flow path 97: flow path 99: Developing device

Claims (3)

[Claims] 1. A developer supply device for supplying a developer comprising an alkaline aqueous solution to a developing process, wherein a supply tank for storing the developer to be supplied and a temperature of the recovered used developer are adjusted to be constant. For recovering the used developer to the supply storage tank, a stock solution supply mechanism for sending new developer stock solution to the supply storage tank, and a recovery solution supply mechanism for supplying the used developer to the supply storage tank. A densitometer for detecting an alkali concentration and a resin concentration of a used developer at a constant temperature to be liquefied is provided, and the densitometer measures an ultrasonic wave propagation speed in the developer and an electromagnetic conductivity of the developer, and A multi-component densitometer for detecting alkali concentration and resin concentration based on the relationship between the ultrasonic wave propagation velocity and electromagnetic conductivity at a given temperature and a given concentration, and detection by the densitometer A developer supply device, wherein the liquid supply of the developer stock solution by the stock solution supply mechanism can be controlled based on the concentration. 2. A diluting water supply mechanism for supplying diluting water to a supply storage tank, a second temperature adjusting means for adjusting the temperature of the developing solution in the supply storage tank to a constant value, and a developing solution at a constant temperature in the supply storage tank. A second densitometer for detecting the alkali concentration and the resin concentration, the second densitometer being a multi-component densitometer similar to the densitometer described above, and the detection by the second densitometer The developer supply device according to claim 1, wherein the liquid supply of the developer stock solution by the stock solution supply mechanism and the liquid supply of the dilution water by the dilution water supply mechanism can be controlled based on the concentration. 3. The second temperature adjusting means is provided with a temperature sensor for detecting the temperature of the developing solution, and the second densitometer measures the alkali concentration and the resin concentration in the supply storage tank. The developer supply device according to claim 2, further comprising a function of performing a correction calculation based on the temperature of the developer detected by the temperature sensor of the second temperature adjusting unit.