Apparatus for stripping photoresist and control method thereof

Abstract

The present application relates to a kind of stripping photoresist device, including active ingredient adding device, replenishment monitoring device, several stripping tanks and several storage tanks, several stripping tanks are respectively connected with storage tank, several storage tanks are interconnected;Storage tank at least includes first storage tank and Nth storage tank, first storage tank is provided with liquid outlet pipe, Nth stripping tank is provided with liquid inlet pipe;Active ingredient adding device and first storage tank are connected by pipeline, switch valve is provided on pipeline;Replenishment monitoring device is connected with first storage tank and active ingredient adding device respectively, and replenishment monitoring device is connected with active ingredient adding device communication;Replenishment monitoring device adds stripping liquid new liquid to Nth storage tank by liquid inlet pipe, and replenishment monitoring device discharges stripping liquid waste liquid in first storage tank by liquid outlet pipe, and replenishment monitoring device controls the communication state between several storage tanks.The present application also relates to a kind of control above-mentioned stripping photoresist device's method.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a device for stripping photoresist and a control method thereof. BACKGROUND

[0002] Thin Film Transistor Liquid Crystal Display (TFT-LCD) can be regarded as a layer of liquid crystal sandwiched between two glass substrates, a color filter (CF) substrate is arranged on the upper glass substrate, and a thin film transistor (TFT) is arranged on the lower glass substrate. When current passes through the thin film transistor, an electric field changes, and the change of the electric field causes the liquid crystal molecules to deflect, thereby changing the polarization of light to achieve the desired display image.

[0003] In the process of the TFT substrate of the TFT-LCD, multiple process technologies are required, each of which involves stripping of photoresist, and a stripper is widely used in the stripping process after pattern formation. The basic composition of the existing water-based stripper includes organic amine, organic solvent, additive, and water. The existing method for stripping photoresist is to melt the photoresist into the stripper, and the organic amine can cut the macromolecules of the photoresist into small molecules, and the organic solvent can penetrate the photoresist to make it soften, swell, and dissolve, and then the photoresist is stripped. Since the photoresist is melted into the stripper to strip the photoresist, the concentration of the photoresist in the stripper will gradually increase after the photoresist is stripped, which will gradually reduce the stripping ability of the stripper.

[0004] The consumption of the stripper in the process of the TFT substrate is relatively large, and the production cost of the stripper is relatively high. In the stripping reaction process of the water-based stripper, the water content will gradually decrease, and when it decreases to a certain extent, the waste stripper in the stripping tank (i.e. the tank containing the stripper) needs to be discharged and replaced with new stripper. The discharged waste stripper contains a high concentration of organic substances (including organic amine and organic solvent), and the stripper is not fully utilized. SUMMARY

[0005] In view of the technical problems in the prior art, the present application provides a device for stripping photoresist and a control method thereof, which can reduce the effective components in the discharged waste stripper, thereby reducing the frequency of updating the stripper, and thus significantly improving the utilization rate of the stripper.

[0006] The present application provides a device for stripping photoresist, which comprises an effective component adding device, a replenishment monitoring device, a plurality of stripping tanks, and a plurality of storage tanks. The number of the stripping tanks is the same as that of the storage tanks, the plurality of stripping tanks are respectively connected with the storage tanks, and the plurality of storage tanks are connected with each other.

[0007] The stripping tank is a tank body containing stripping liquid. The TFT substrate is put into the stripping liquid in the stripping tank to strip the photoresist. The TFT substrate is put into different stripping tanks in turn to strip the photoresist. Therefore, according to the order of putting the TFT substrate into the stripping tank, the several stripping tanks are marked as "first stripping tank", "second stripping tank", "third stripping tank",..., and "Nth stripping tank" (N is a positive integer not less than 2). That is, the TFT substrate is first put into the stripping liquid in the first stripping tank, then into the stripping liquid in the second stripping tank, then into the stripping liquid in the third stripping tank,..., and finally into the stripping liquid in the Nth stripping tank. The process is unidirectional and linear.

[0008] At the same time, the storage tank connected with the first stripping tank is marked as the first storage tank, the storage tank connected with the second stripping tank is marked as the second storage tank, the storage tank connected with the third stripping tank is marked as the third storage tank,..., and the storage tank connected with the Nth stripping tank is marked as the Nth storage tank. In addition, the first storage tank is provided with a liquid outlet pipe, and the Nth stripping tank is provided with a liquid inlet pipe. The liquid outlet pipe is used to discharge stripping liquid waste, and the liquid inlet pipe is used to introduce new stripping liquid.

[0009] The initial parameter state (including components, content of each component, temperature of the stripping liquid, volume of the stripping liquid, etc.) of the stripping liquid in the several stripping tanks is the same. During the process of stripping the photoresist of the TFT substrate, the consumption rate of the organic substances (including organic amines and organic solvents) in the stripping liquid in each stripping tank gradually decreases from the first stripping tank to the Nth stripping tank, and the photoresist concentration of the stripping liquid in each stripping tank gradually increases from the Nth stripping tank to the first stripping tank. The stripping liquid is stored in the several storage tanks, and the state parameters of the stripping liquid stored in the storage tank are the same as those of the stripping liquid in the stripping tank connected with the storage tank. Therefore, by monitoring the state parameters of the stripping liquid in the storage tank, the state parameters of the stripping liquid in the stripping tank connected with the storage tank can be obtained. At the same time, by changing the state parameters of the stripping liquid in the storage tank, the state parameters of the stripping liquid in the stripping tank connected with the storage tank can be changed synchronously.

[0010] The effective component adding device and the first storage tank are connected by a pipeline, and a switch valve for controlling the connection or disconnection of the pipeline is arranged on the pipeline. In an embodiment, the switch valve is an electromagnetic valve. The effective component adding device is used to supplement deionized water to the stripping liquid in the first stripping tank, so as to adjust the water concentration of the stripping liquid added to the first stripping tank in real time.

[0011] The replenishment monitoring device is connected with the first storage tank and the effective component adding device respectively. The replenishment monitoring device is in communication connection with the effective component adding device. The replenishment monitoring device is used for monitoring the concentration of the stripping liquid in the first storage tank, and the replenishment monitoring device also realizes the following controls: 1. adding new stripping liquid to the Nth storage tank through the liquid inlet pipe; 2. discharging waste stripping liquid in the first storage tank through the liquid outlet pipe; 3. controlling the effective component adding device to add deionized water to the first storage tank; and 4. controlling the communication state between the storage tanks.

[0012] In another aspect, the application also provides a method for controlling the device for stripping photoresist, comprising the following steps:

[0013] Step S1: the replenishment monitoring device monitors the state parameters of the stripping liquid in the first storage tank, including water concentration and photoresist concentration;

[0014] Step S2: when the water concentration of the stripping liquid in the first storage tank is lower than a preset value, the replenishment monitoring device sends a corresponding signal to the effective component adding device, and the effective component adding device performs the following actions after accepting the signal: 1. opening the switch valve and starting to add deionized water to the first storage tank; and 2. closing the switch valve and stopping water replenishment after reaching the set water replenishment time.

[0015] Step S3: repeating steps S1-S2 until the water concentration of the stripping liquid in the first storage tank is not less than the preset value.

[0016] Step S4: as the number of water replenishment increases and the stripping photoresist process proceeds, the photoresist concentration and the water concentration of the stripping liquid in the first storage tank gradually increase, and the concentration of organic substances (including organic amines and organic solvents) in the stripping liquid in the first storage tank gradually decreases. When the photoresist concentration and the water concentration of the stripping liquid in the first storage tank reach the balance condition (i.e. the photoresist concentration reaches the set upper limit value), the replenishment monitoring device is adjusted to monitor the photoresist concentration of the stripping liquid in the first storage tank.

[0017] Step S5: when the replenishment monitoring device monitors that the photoresist concentration of the stripping liquid in the first storage tank is higher than the set upper limit value, the replenishment monitoring device performs the following actions simultaneously: 1. controlling the communication between the storage tanks; 2. adding new stripping liquid to the Nth storage tank through the liquid inlet pipe; and 3. discharging waste stripping liquid in the first storage tank through the liquid outlet pipe. At this time, the component concentrations (including water concentration and photoresist concentration) of the stripping liquid between the first storage tank and the Nth storage tank reach dynamic balance, i.e. the component concentrations (including water concentration and photoresist concentration) of the stripping liquid between the first stripping tank and the Nth stripping tank reach dynamic balance.

[0018] Step S6, when the replenishment monitoring device monitors that the photoresist concentration of the stripping liquid in the first storage tank decreases to not more than the set lower limit value, the replenishment monitoring device will simultaneously perform the following actions: 1. Control the disconnection between a plurality of storage tanks; 2. Stop adding new stripping liquid to the Nth storage tank through the liquid inlet pipe; 3. Stop discharging the waste stripping liquid in the first storage tank through the liquid outlet pipe, at this time the stripping liquid in the first storage tank does not affect the stripping effect, and the stripping liquid in the first storage tank is fully used;

[0019] Step S7, repeat steps S1-S6.

[0020] Compared with the prior art, the technical scheme provided by the present application has at least the following beneficial effects:

[0021] 1. Improve the use efficiency of stripping liquid and reduce production cost;

[0022] 2. Optimize the stripping liquid management mode, the number of stripping liquid updates is significantly reduced, and the consumption is significantly reduced.

[0023] The following will be described in conjunction with specific embodiments BRIEF DESCRIPTION OF DRAWINGS

[0024] The drawings further illustrate the present application, but the embodiments in the drawings do not constitute any limitation on the present application.

[0025] Figure 1 The device structure diagram for stripping photoresist provided by an embodiment of the present application.

[0026] Among them, the signs are: 1. Replenishment monitoring device; 21. Active ingredient adding device; 22. Solenoid valve; 31. First stripping tank; 32. Second stripping tank; 33. Third stripping tank; 34. Fourth stripping tank; 41. First storage tank; 42. Second storage tank; 43. Third storage tank; 44. Fourth storage tank; 51. Liquid inlet pipe; 52. Liquid outlet pipe. DETAILED DESCRIPTION

[0027] The specific structure and functional details disclosed herein are only representative, and are for the purpose of describing the exemplary embodiments of the present application. However, the present application can be embodied in many alternative forms, and should not be interpreted as being limited only to the embodiments set forth herein.

[0028] In the description of the present application, it needs to be understood that the terms "center", "transverse", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" can be explicitly or implicitly included one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more. In addition, the term "includes" and any variations thereof are intended to cover non-exclusive inclusion.

[0029] In the description of the present application, it needs to be understood that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0030] The terms used herein are only used to describe specific embodiments and are not intended to limit the exemplary embodiments. Unless the context clearly indicates otherwise, as used herein, the singular form "a", "an" and "the" is also intended to include the plural. It should also be understood that the terms "include" and / or "contain" specify the existence of the stated features, integers, steps, operations, units and / or components, and do not exclude the existence or addition of one or more other features, integers, steps, operations, units, components and / or combinations thereof.

[0031] The following refers to Figure 1 The device for stripping photoresist and the control method are described.

[0032] The present embodiment provides a device for stripping photoresist, comprising: a replenishment monitoring device 1, an effective component adding device 21, a first stripping groove 31, a second stripping groove 32, a third stripping groove 33, a fourth stripping groove 34, a first storage groove 41, a second storage groove 42, a third storage groove 43, and a fourth storage groove 44.

[0033] The fourth storage groove 44 is provided with a liquid inlet pipe 51, and the first storage groove 41 is provided with a liquid outlet pipe 52.

[0034] The first stripping tank 31, the second stripping tank 32, the third stripping tank 33 and the fourth stripping tank 34 are used for placing stripping liquid, wherein the stripping liquid is a chemical liquid used for stripping photoresist. The fresh stripping liquid recorded in the embodiment is a stripping liquid which has not been used for stripping photoresist. The waste stripping liquid recorded in the embodiment is a stripping liquid which has been used for stripping photoresist.

[0035] When the photoresist stripping process is performed, the TFT substrate is first placed in the stripping liquid in the first stripping tank 31, then placed in the stripping liquid in the second stripping tank 32, then placed in the stripping liquid in the third stripping tank 33, and finally placed in the stripping liquid in the fourth stripping tank 34. The process is unidirectional and linear.

[0036] The first stripping tank 31 and the first storage tank 41 are in communication, the second stripping tank 32 and the second storage tank 42 are in communication, the third stripping tank 33 and the third storage tank 43 are in communication, and the fourth stripping tank 34 and the fourth storage tank 44 are in communication. The first storage tank 41, the second storage tank 42, the third storage tank 43 and the fourth storage tank 44 can realize the circulation of the stripping liquid.

[0037] The effective component adding device 21 and the first storage tank 41 are connected by a pipeline, and an electromagnetic valve 22 is arranged on the pipeline. The effective component adding device 21 is used to supplement deionized water to the stripping liquid in the first stripping tank 41, so as to adjust the water concentration of the stripping liquid in the first stripping tank in real time. At the same time, the effective component adding device 21 controls the on-off of the electromagnetic valve 22.

[0038] The replenishment monitoring device 1 is connected with the first storage tank 41 and the effective component adding device 21 respectively. The replenishment monitoring device 21 is in communication connection with the effective component adding device 1, and the effective component adding device 1 can control the on-off of the electromagnetic valve 22 through the effective component adding device 21. The replenishment monitoring device 1 is used to monitor the concentration of the stripping liquid in the first storage tank 41. The replenishment monitoring device 1 can detect the photoresist concentration and the water concentration of the stripping liquid in the first storage tank 41. The replenishment monitoring device 1 realizes the following controls through the detected photoresist concentration and water concentration of the stripping liquid in the first storage tank 41: 1. adding the fresh stripping liquid to the fourth storage tank 44 through the liquid inlet pipe 51; 2. discharging the waste stripping liquid in the first storage tank 41 through the liquid outlet pipe 52; 3. controlling the effective component adding device 1 to add deionized water to the first storage tank 41; and 4. controlling the communication state among the first storage tank 41, the second storage tank 42, the third storage tank 43 and the fourth storage tank 44.

[0039] And the replenishment monitoring device 1 can prevent waste by adding too much stripping liquid to the fourth storage tank 44 and prevent affecting the stripping ability of the stripping liquid in the first storage tank 41 by discharging too little stripping liquid waste from the first storage tank 41 by detecting the photoresist concentration of the stripping liquid in the first storage tank 41, controlling the outflow of the liquid outlet pipe 52, and controlling the injection amount of the liquid inlet pipe 51.

[0040] In this embodiment, the replenishment monitoring device 1 extracts part of the stripping liquid in the first storage tank 41 and irradiates the part of the stripping liquid with a beam of near-infrared light, and because different components vibrate differently after absorbing light, a spectrum data can be obtained. The replenishment monitoring device 1 can obtain the concentration of each component in the stripping liquid in the first storage tank 41 by analyzing the change in light intensity before and after and the spectrum data. The replenishment monitoring device 1 can collect the photoresist concentration and water concentration of the stripping liquid in the first storage tank 41.

[0041] In this embodiment, solenoid valves are arranged on the communication pipe between the first storage tank 41 and the second storage tank 42, on the communication pipe between the second storage tank 42 and the third storage tank 43, and on the communication pipe between the third storage tank 43 and the fourth storage tank 44 (not shown in the figure), and the solenoid valves are connected to the replenishment monitoring device 1. The replenishment monitoring device 1 can control the communication state between the first storage tank 41, the second storage tank 42, the third storage tank 43, and the fourth storage tank 44 by controlling the solenoid valves.

[0042] On the other hand, the embodiment also provides a method for controlling the above-mentioned stripping photoresist device, comprising the following steps:

[0043] Step S1, the replenishment monitoring device 1 monitors the state parameters of the stripping liquid in the first storage tank 41, including the water concentration and the photoresist concentration;

[0044] Step S2, when the water concentration of the stripping liquid in the first storage tank 41 is lower than the preset value, the replenishment monitoring device 1 sends a corresponding signal to the active ingredient adding device 21, and the active ingredient adding device 21 performs the following actions after receiving the signal: 1. Open the electromagnetic valve 22 and start adding deionized water to the first storage tank 41; 2. Close the electromagnetic valve 22 and stop water replenishment after reaching the set water replenishment time;

[0045] Step S3, repeat steps S1-S2 until the water concentration of the stripping liquid in the first storage tank 41 is not less than the preset value;

[0046] Step S4, with the increase of the number of water replenishment and the proceeding of the stripping photoresist process, the photoresist concentration and the water concentration of the stripping liquid in the first storage tank 41 gradually increase, and the concentration of organic substances (including organic amine and organic solvent) in the stripping liquid in the first storage tank 41 gradually decreases. When the photoresist concentration of the stripping liquid in the first storage tank 41 reaches the balance condition (i.e. the photoresist concentration reaches the set upper limit value), the replenishment monitoring device 1 is adjusted to monitor the photoresist concentration of the stripping liquid in the first storage tank 41.

[0047] Step S5, when the replenishment monitoring device 1 monitors that the photoresist concentration of the stripping liquid in the first storage tank is higher than the set upper limit value, the replenishment monitoring device 1 simultaneously performs the following actions: 1. controls the communication between the first storage tank 41, the second storage tank 42, the third storage tank 43 and the fourth storage tank 44; 2. adds new stripping liquid to the fourth storage tank 44 through the liquid inlet pipe 51; 3. discharges the waste stripping liquid in the first storage tank 41 through the liquid outlet pipe 52. At this time, the component concentrations (including water concentration and photoresist concentration) of the stripping liquid between the first storage tank 41, the second storage tank 42, the third storage tank 43 and the fourth storage tank 44 reach a dynamic balance, i.e. the component concentrations (including water concentration and photoresist concentration) of the stripping liquid between the first stripping tank 31, the second stripping tank 32, the third stripping tank 33 and the fourth stripping tank 34 reach a dynamic balance.

[0048] Step S6, when the replenishment monitoring device 1 monitors that the photoresist concentration of the stripping liquid in the first storage tank 41 decreases until it is not greater than the set lower limit value, the replenishment monitoring device 1 simultaneously performs the following actions: 1. controls the disconnection of the communication between the first storage tank 41, the second storage tank 42, the third storage tank 43 and the fourth storage tank 44; 2. stops adding new stripping liquid to the fourth storage tank 44 through the liquid inlet pipe 51; 3. stops discharging the waste stripping liquid in the first storage tank 41 through the liquid outlet pipe 52. At this time, the stripping liquid in the first storage tank 41 does not affect the stripping effect, and the stripping liquid in the first storage tank is fully used.

[0049] Step S7, repeat steps S1-S6.

[0050] The embodiment of the present application prevents the waste of stripping liquid, reduces the manufacturing cost, and solves the technical problems of stripping liquid waste and high manufacturing cost. The number of stripping liquid replacement is significantly reduced, and the consumption of stripping liquid is reduced.

[0051] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not exist, they should be considered as the scope of the present disclosure.

[0052] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A control method of a device for stripping photoresist, characterized in that the device comprises an effective component adding device, a replenishment monitoring device, a plurality of stripping tanks and a plurality of storage tanks, the number of the stripping tanks and the storage tanks is the same, a plurality of the stripping tanks are respectively connected with the storage tanks, and a plurality of the storage tanks are connected with each other; the storage tanks at least comprise a first storage tank and an Nth storage tank, N is a positive integer not less than 2, the first storage tank is provided with a liquid outlet pipe, and the Nth storage tank is provided with a liquid inlet pipe; the effective component adding device and the first storage tank are connected through a pipeline, and a switch valve is arranged on the pipeline; the replenishment monitoring device is connected with the first storage tank and the effective component adding device respectively, and the replenishment monitoring device is communicatively connected with the effective component adding device; the replenishment monitoring device adds stripping liquid new liquid to the Nth storage tank through the liquid inlet pipe, discharges stripping liquid waste liquid in the first storage tank through the liquid outlet pipe, and controls the connection state between a plurality of the storage tanks; the control method comprises the following steps: step S1, the replenishment monitoring device monitors state parameters of stripping liquid in the first storage tank, including water concentration and photoresist concentration; step S2, when the water concentration of the stripping liquid in the first storage tank is lower than a preset value, the replenishment monitoring device sends a corresponding signal to the effective component adding device, and after receiving the signal, the effective component adding device performs the following actions:

1. opens the switch valve and starts to add deionized water to the first storage tank; 2. closes the switch valve and stops water replenishment after reaching a set water replenishment time; step S3, steps S1-S2 are repeated until the water concentration of the stripping liquid in the first storage tank is not less than a preset value; step S4, when the photoresist concentration of the stripping liquid in the first storage tank reaches a set upper limit value, the replenishment monitoring device is adjusted to monitor the photoresist concentration of the stripping liquid in the first storage tank; step S5, when the replenishment monitoring device monitors that the photoresist concentration of the stripping liquid in the first storage tank is higher than a set upper limit value, the replenishment monitoring device simultaneously performs the following actions:

1. controls the connection between a plurality of the storage tanks; 2. adds stripping liquid new liquid to the Nth storage tank through the liquid inlet pipe; 3. discharges stripping liquid waste liquid in the first storage tank through the liquid outlet pipe; step S6, when the replenishment monitoring device monitors that the photoresist concentration of the stripping liquid in the first storage tank decreases until not more than a set lower limit value, the replenishment monitoring device simultaneously performs the following actions:

1. controls the disconnection between a plurality of the storage tanks; 2. stops adding stripping liquid new liquid to the Nth storage tank through the liquid inlet pipe; 3. stops discharging stripping liquid waste liquid in the first storage tank through the liquid outlet pipe. The switch valve is an electromagnetic valve. The number of the stripping tanks and the storage tanks is four. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2. The control method according to claim 1, characterized by, ​ 3. The control method according to claim 1, characterized by, ​

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