Photoresist stripping solution and method of use thereof

Abstract

The present invention provides a photoresist stripping solution and a method for using the same.SOLUTION: The photoresist stripping solution includes a first stripping solution and a second stripping solution. The photoresist stripping solution does not comprise an organic base, and the first stripping solution comprises an inorganic base, 3% to 15% by weight of a first azole compound, 2% to 10% by weight of a surfactant, and water. Inorganic bases include potassium hydroxide and sodium hydroxide. The second stripping solution comprises 30 wt% to 80 wt% of an alcohol ether solvent, 1 wt% to 15 wt% of a second azole compound, and water. The concentration of the inorganic base in the first stripping solution is 30g / L to 45g / L.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a photoresist stripping solution and a method for using the same, and more particularly, to a photoresist stripping solution that does not contain organic amines and a method for using the same.

Background Art

[0002] The manufacturing process of a circuit board includes steps such as forming a copper surface, applying and developing a photoresist on the copper surface to cover a part of the copper surface with a dry film, etching the exposed copper surface, and stripping the dry film.

[0003] In the step of stripping the dry film, usually, a stripping solution is used to remove the photoresist dry film covering the fine pitch. Currently, existing stripping solutions mainly composed of sodium hydroxide have the advantages of low cost and high stripping speed, but the scrap generated after stripping is relatively large. For fine pitch, there is a defect that the film cannot be peeled cleanly, resulting in a circuit board that fails to pass quality control.

[0004] Therefore, another type of film stripping solution containing inorganic bases and organic bases is also commercially available. Organic bases are usually amine compounds such as ethanolamine and ethylenediamine. When inorganic bases and organic bases coexist, a better stripping effect can be obtained. However, due to the generation of a pungent odor in the stripping solution due to the presence of organic amines, there is room for improvement.

[0005] Therefore, improving the composition to eliminate the use of organic amines while maintaining a certain degree of stripping effect has become one of the important issues for those skilled in the art.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The technological problem that this invention aims to solve is to provide a photoresist stripping solution and a method of using the same, in response to the shortcomings of the prior art. [Means for solving the problem]

[0007] To solve the above technical problems, one of the technical means employed by the present invention is to provide a photoresist stripping solution comprising a first stripping solution and a second stripping solution. The photoresist stripping solution does not contain an organic base. The first stripping solution comprises an inorganic base, 1% to 15% by weight of a first azole compound, 2% to 10% by weight of a surfactant, and water. The inorganic base includes potassium hydroxide and sodium hydroxide. The second stripping solution comprises 30% to 80% by weight of an alcohol ether solvent, 1% to 15% by weight of a second azole compound, and water. The concentration of the inorganic base in the first stripping solution is 30 g / L to 45 g / L.

[0008] In one embodiment, the weight ratio of potassium hydroxide to sodium hydroxide is 2.5 to 6.

[0009] In one embodiment, the first azole compound is selected from the group consisting of benzotriazole, mercaptobenzothiazole, methylbenzotriazole, and 5-phenyltetrazole.

[0010] In one embodiment, the second azole compound is selected from the group consisting of benzotriazole, mercaptobenzothiazole, methylbenzotriazole, and 5-phenyltetrazole.

[0011] In one embodiment, the surfactant is selected from the group consisting of sodium dodecyl sulfate, octadecyltrimethylammonium hydroxide, alkyldimethylphenylammonium hydroxide, alkyl sulfate ester salt, phosphate ester salt, sulfosuccinate ester, glutamate, lauryl betaine, cocamidopropyl betaine, and polyoxyethylene lauryl ether potassium phosphate.

[0012] In one embodiment, the alcohol ether solvent is selected from the group consisting of diethylene glycol butyl ether, diethylene glycol methyl ether, diethylene glycol propyl ether, dipropylene glycol propyl ether, propylene glycol n-butyl ether, diethylene glycol dibutyl ether, tripylene glycol methyl ether, ethylene glycol butyl ether, ethylene glycol propyl ether, diethylene glycol hexyl ether, diethylene glycol diethyl ether, and diethylene glycol dimethyl ether.

[0013] To solve the above technical problems, another technical means employed by the present invention is to provide a method for using a photoresist stripping solution. The method for using the photoresist stripping solution includes applying a first stripping solution to a circuit board, applying a second stripping solution to a circuit board, preparing a third stripping solution by mixing the first and second stripping solutions in a weight ratio of 1:1 to 2:3 (first stripping solution:second stripping solution) and further adding 1 to 2.5 times the amount of water, and applying the third stripping solution to the circuit board. The first stripping solution does not contain an organic base, but contains an inorganic base, 1% to 15% by weight of a first azole compound, 2% to 10% by weight of a surfactant, and water, and the concentration of the inorganic base in the first stripping solution is 30 g / L to 45 g / L. The second stripping solution contains 30% to 80% by weight of an alcohol ether-based solvent, 1% to 15% by weight of the second azole compound, and water, without containing an organic base.

[0014] In one embodiment, the first stripping solution, the second stripping solution, and the third stripping solution are applied to the circuit board by spraying.

[0015] To solve the above technical problems, another technical means employed by the present invention is to provide a photoresist stripping solution. The photoresist stripping solution contains an inorganic base, 1% to 5% by weight of an azole compound, 1% to 10% by weight of a surfactant, 30% to 80% by weight of an alcohol ether solvent, and water, without containing an organic base. The inorganic base includes potassium hydroxide and sodium hydroxide. The concentration of the inorganic base in the photoresist stripping solution is 1.5 g / L to 26 g / L.

[0016] In one embodiment, the azole compound comprises at least one of benzotriazole, mercaptobenzothiazole, methylbenzotriazole, and 5-phenyltetrazole. [Effects of the Invention]

[0017] One of the advantageous effects of the present invention is that, due to the technical features of the photoresist stripping solution and method of use according to the present invention, "the first stripping solution contains an inorganic base, a first azole compound, and a surfactant," and "the second stripping solution contains an alcohol ether solvent and a second azole compound," a good stripping effect can be achieved without containing an organic base. [Brief explanation of the drawing]

[0018] [Figure 1] This is a flowchart showing a method for using the photoresist stripping solution according to the present invention. [Figure 2] This is a schematic diagram illustrating the stripping process performed on a circuit board. [Modes for carrying out the invention]

[0019] To further understand the features and technical content of this invention, please refer to the following detailed description and drawings relating to the invention. However, the drawings provided are for reference and illustrative purposes only and do not limit the scope of the claims of this invention.

[0020] The "photoresist stripping solution and method of use thereof" will be described below by specific embodiments, and those skilled in the art will be able to understand the advantages and effects of the present invention based on what is disclosed herein. The present invention can be carried out or applied by other different specific embodiments, and various modifications and changes can be made to each detail herein, based on different viewpoints and applications, as long as they do not deviate from the concept of the present invention. It should also be noted in advance that the accompanying drawings of the present invention are for simple schematic explanation and are not drawn to actual size. The technical content of the present invention will be described in more detail below by the embodiments, but the scope of protection of the present invention is not limited by what is disclosed. The term "or" as used herein may include any one or more combinations of the items listed in relation to the actual situation.

[0021] In the present invention, by adjusting the composition of the stripping solution and improving the method of using the stripping solution, even if an organic base (amine compound) is removed from the photoresist stripping solution, a good stripping effect can still be achieved. Therefore, the photoresist stripping solution of the present invention can be used for fine pitches of 3 mils or more, replacing the existing stripping solutions with a pungent odor.

[0022] The photoresist stripping solution according to the present invention is a two-component type photoresist stripping solution containing a first stripping solution and a second stripping solution independently packaged. The first stripping solution and the second stripping solution may be used independently, or may be used after mixing the first stripping solution and the second stripping solution. The above combination exhibits an excellent stripping effect for all currently commercially available photoresists.

[0023] For example, as the types of photoresists to be applied, there are ADH photoresists (photoresists containing acrylic monomers), t-BOC photoresists (photoresists containing a tertiary butoxycarbonyl group), and acetal photoresists (photoresists containing PHS copolymers), but the present invention is not limited thereto. The above types are merely examples and do not limit the types of applicable photoresists.

[0024] In the photoresist stripping solution, the first stripping solution is for stripping the dry film (formed by the photoresist). The second stripping solution actually has no stripping effect, but can expand the dry film, and the expanded dry film can react more easily with the first stripping solution and can be removed from the circuit board. That is, the second stripping solution can assist the first stripping solution in stripping the dry film.

[0025] [First Stripping Solution] The first stripping solution is an aqueous solution and does not contain an organic base (amine compound). The first stripping solution contains an inorganic base, 1 wt% - 15 wt% of a first azole compound, 2 wt% - 10 wt% of a surfactant, and water. Here, the concentration of the inorganic base in the first stripping solution is 30 g / L - 45 g / L. Also, all other components other than the inorganic base, the first azole compound, and the surfactant are water.

[0026] The inorganic base includes potassium hydroxide and sodium hydroxide, and the content by weight of potassium hydroxide in the first stripping solution is more than the content by weight of sodium hydroxide in the first stripping solution. In a certain exemplary embodiment, the weight ratio of potassium hydroxide to sodium hydroxide in the first stripping solution is 2.5 - 6, for example, 3, 3.5, 4, 4.5, 5, or 5.5.

[0027] Also, the concentration of the inorganic base (i.e., potassium hydroxide and sodium hydroxide) in the first stripping solution may be any real number between 30 g / L and 45 g / L. Preferably, the concentration of the inorganic base in the first stripping solution may be 32 g / L, 34 g / L, 36 g / L, 38 g / L, 40 g / L, 42 g / L, or 44 g / L.

[0028] The preparation method exemplified in this specification is to first prepare a potassium hydroxide solution and a sodium hydroxide solution respectively, mix an appropriate amount of the potassium hydroxide solution and the sodium hydroxide solution, then add other components (the first azole compound and the surfactant), and finally add water to reach the final volume. The specific preparation process will be described in the examples.

[0029] The inorganic base has the effect of hydrolyzing (saponifying) esters. Therefore, the inorganic base in the first stripping solution can block the cross-linking of the main chain of the photoresist, peel the dry film into a plurality of flakes, and achieve the peeling effect of the dry film.

[0030] Compared to film dissolution mechanisms using organic bases, the film peeling mechanism using inorganic bases of the present invention offers further advantages for continuous manufacturing processes. Since the peeled dry film is in sheet form, it can be easily removed by filtration, reducing the problem of wastewater treatment.

[0031] It is worth noting that when inorganic bases are typically used as stripping solutions, carboxylic acids, also known as fatty acid soaps, are generated during the saponification process of photoresist, making foaming more likely. Therefore, problems such as excessive foaming tend to occur during the process of stripping photoresist with inorganic bases, and if bubbles adhere to the circuit board, the photoresist stripping effect decreases, leading to a decline in production efficiency and yield.

[0032] To avoid problems such as excessive foaming, the present invention utilizes the property of surfactants to readily dissociate and form ions in a strong alkali, thereby reducing the structural stability of the foam and preventing the formation of foam that persists for a long period of time. Furthermore, it is possible to avoid excessive foaming which could adversely affect the peeling effect of low-grade photoresists.

[0033] Since the selected inorganic base is strongly alkaline and its addition concentration is relatively high, the present invention adds a first azole compound to avoid erosion of the copper circuit during the dry film peeling process, thereby achieving the effect of protecting the copper surface. Furthermore, the content of the first azole compound in the first peeling solution may be any real number between 3% by weight and 15% by weight. Preferably, the content of the first azole compound in the first peeling solution is 5% by weight to 15% by weight.

[0034] Azoles are compounds containing a five-membered heterocycle, the skeleton of which has at least two heteroatoms, and at least two of these heteroatoms have at least one nitrogen atom.

[0035] Experiments have shown that it is preferable to select an azole compound containing three or more nitrogen atoms. For example, triazole or tetrazole. Specifically, the first azole compound may be benzotriazole (BTA), methylbenzotriazole (TTA), or 5-phenyl-1H-tetrazole, but the present invention is not limited thereto. On the other hand, if the azole compound has a mercapto group, it exhibits excellent adhesion to copper atoms, so a thiazole compound containing only one nitrogen atom and one sulfur atom may be selected. Therefore, the first azole compound may be mercaptobenzothiazole.

[0036] The addition of a surfactant can improve the wettability of the first stripping solution, which is advantageous for the penetration of inorganic bases between circuits, thereby improving the stripping ability and speed. The surfactant content in the first stripping solution may be any real number between 2% by weight and 10% by weight.

[0037] Furthermore, the addition of a surfactant contributes to the dispersion of the first azole compound in the first stripping solution. Generally, azole compounds have low solubility in water, and since the first stripping solution is an aqueous solution, the presence of a surfactant is essential.

[0038] In some embodiments, the surfactant may be sodium dodecyl sulfate, octadecyltrimethylammonium hydroxide, alkyldimethylphenylammonium hydroxide, alkyl sulfate salts, phosphate salts, sulfosuccinates, glutamates, lauryl betaine, cocamidopropyl betaine, or potassium polyoxyethylene lauryl ether phosphate, but the present invention is not limited thereto.

[0039] [Second stripping solution] The second stripping solution is mainly an organic solution and does not contain organic bases (amine compounds). The second stripping solution contains 30% to 80% by weight of an alcohol ether solvent, 5% to 15% by weight of the second azole compound, and water. All other components besides the alcohol ether solvent and the second azole compound are water.

[0040] Alcohol ether-based solvents can permeate the photoresist in a way that causes the dry film to swell, thus contributing to the detachment of the dry film. In the presence of the first stripping solution, the alcohol ether-based solvent can cause the dry film to swell, providing a pathway for reaction between the inorganic base and the dry film, thereby achieving an effect of improving the stripping speed.

[0041] For example, the alcohol ether solvent may be diethylene glycol butyl ether, diethylene glycol methyl ether, diethylene glycol propyl ether, dipropylene glycol propyl ether, propylene glycol n-butyl ether, diethylene glycol dibutyl ether, tripropylene glycol methyl ether, ethylene glycol butyl ether, ethylene glycol propyl ether, diethylene glycol hexyl ether, diethylene glycol diethyl ether, and diethylene glycol dimethyl ether.

[0042] An azole compound is also added to the second stripping solution. The azole compound protects the copper circuit and prevents corrosion by residual inorganic bases. The applicable azole compounds are similar to those described above, so no redundant explanation is given here. The second azole compound may be benzotriazole, mercaptobenzothiazole, methylbenzotriazole, or 5-phenyltetrazole. It should be noted that the first azole compound may be the same as or different from the second azole compound.

[0043] [How to use photoresist stripping solution] As shown in Figure 1, the photoresist stripping solution according to the present invention is a two-part type photoresist stripping solution. When using the photoresist stripping solution, first, the first stripping solution is applied to the circuit board to remove most of the dry film (step S1). Then, the second stripping solution is applied to further expand the dry film and reduce the adhesion between the dry film and the circuit board (step S2). Subsequently, the first and second stripping solutions are mixed in a specific ratio to prepare the third stripping solution (step S3). The third stripping solution is applied to the circuit board to remove any remaining dry film (step S4).

[0044] The first azole compound in the first stripping solution adheres to the exposed circuit portion, achieving a protective effect on the copper surface. The inorganic base disrupts the crosslinking of the photoresist main chain, peeling off the dry film as a sheet, and the surfactant stably disperses it into the first stripping solution. However, since the first stripping solution does not easily penetrate areas with narrow circuit pitches, a second stripping solution is added. The second stripping solution expands the dry film, providing a pathway for the first stripping solution to penetrate areas with narrow circuit pitches. Therefore, after adding the third stripping solution, the third stripping solution penetrates between the fine pitches, allowing the remaining dry film to be peeled off without damaging the molded circuit.

[0045] In the process of preparing the third stripping solution, the first stripping solution and the second stripping solution are weighed and mixed in a weight ratio of 1:1 to 2:3, and water is added in an amount equal to 1 to 2.5 times the total weight of the weighed first and second stripping solutions to obtain the third stripping solution.

[0046] It is worth noting that the third stripping solution is prepared using the first stripping solution, the second stripping solution, and water, so when designing the components of the second stripping solution, azole compounds are also added. In this way, situations can be avoided where the concentration of azole compounds in the prepared third stripping solution is insufficient to protect the copper surface.

[0047] Specifically, according to the preparation method described above, the third stripping solution contains an inorganic base, 1% to 5% by weight of an azole compound, 1% to 10% by weight of a surfactant, 30% to 80% by weight of an alcohol ether solvent, and water. All other components besides the inorganic base, azole compound, surfactant, and alcohol ether solvent are water. The concentration of the inorganic base in the photoresist stripping solution is 1.5 g / L to 26 g / L.

[0048] Specifically, the concentration of the inorganic base in the first stripping solution is 1.15 to 30 times the concentration of the inorganic base in the third stripping solution. In another embodiment, the ratio of the concentrations of the inorganic base in the first and third stripping solutions (concentration of the inorganic base in the first stripping solution / concentration of the inorganic base in the third stripping solution) may be a positive real number between 1.15 and 30.

[0049] Since the third release agent is mainly used for dry films that are difficult to remove between fine pitches, the amount of the second release agent added is greater than the amount of the first release agent added, in order to expand the dry film and provide a pathway for the third release agent to react with the remaining dry film.

[0050] Since most of the dry film has already been peeled off, a large amount of water is added to prevent the exposed copper surface from being corroded, and the exposed copper surface is protected with the first azole compound and the second azole compound.

[0051] It is worth noting that the first stripping solution is an aqueous solution, while the second stripping solution contains a larger amount of organic solvent, so the first and second stripping solutions may actually separate into layers. However, since the first stripping solution contains a surfactant, mixing the first and second stripping solutions still yields a uniformly mixed third stripping solution.

[0052] As shown in Figure 2, the present invention allows for the application of the stripping solution by spraying, but the present invention is not limited to this. When performing the stripping process, the circuit board S is placed on a conveyor belt B, and the circuit board S is passed sequentially under the supply end L1 of the first stripping solution, the supply end L2 of the second stripping solution, and the supply end L3 of the third stripping solution, and the photoresist stripping solution is sprayed onto the circuit board S according to steps S1, S2, and S4, thereby achieving the effect of stripping the dry film.

[0053] Compared to conventional wet batch equipment, applying the stripping solution by spraying it avoids problems such as stickiness of the dry film after stripping and deterioration of the stripping effect due to aging of the stripping solution after use. Furthermore, adopting the spraying method reduces the amount of stripping solution used, allowing the desired effect to be obtained with the minimum amount.

[0054] [Experimental Examples 1-6] To demonstrate the effectiveness of the photoresist stripping solution according to the present invention, a dry film with a thickness of 25 μm or 30 μm (specific thicknesses are shown in Table 1) was formed on a circuit board using an ADH photoresist mainly composed of acrylic groups. Next, the first stripping solution, the second stripping solution, and the third stripping solution were prepared based on the parts by weight shown in Table 1, and all units not specifically indicated in Table 1 are parts by weight.

[0055] In Experimental Examples 1-6, potassium hydroxide solutions with concentrations of 45% to 50% by weight and sodium hydroxide solutions with concentrations of 45% to 50% by weight were first prepared. Then, the amount of potassium hydroxide solution and sodium hydroxide solution that needed to be weighed and mixed in order for the final first stripping solution to reach the target concentration of inorganic base was calculated.

[0056] Calculations show that 50% to 85% by weight of potassium hydroxide solution and 10% to 25% by weight of sodium hydroxide solution are added to the first stripping solution, but the present invention is not limited thereto.

[0057] Furthermore, the first azole compound used in Experimental Examples 1-6 was benzotriazole, the surfactant was a phosphate ester salt, and the alcohol ether solvent was diethylene glycol butyl ether; the second azole compound was benzotriazole.

[0058] After preparing the first, second, and third stripping solutions, they were placed in three separate beakers. The stripping process was completed by immersing the circuit board in the first, second, and third stripping solutions in that order for 180 seconds each, under conditions of a temperature of 70°C and a rotation speed of 600 rpm.

[0059] In the stripping process, since most of the dry film is removed by the first stripping solution, the time it took for the circuit board to remove 80% of the dry film with the first stripping solution was recorded and defined as the stripping time, and the stripping effect of the first stripping solution on the dry film was evaluated.

[0060] After the stripping process was completed, the stripping ability of the photoresist stripping solution was evaluated based on the amount of dry film remaining. If the amount of dry film remaining was less than 1%, it was indicated with "O". If the amount of dry film remaining was between 1% and 5%, it was indicated with "△". In addition, the oxidation state of the copper surface was evaluated based on the condition of the copper surface. If the proportion of copper oxide on the copper surface was less than 1% of the total copper surface, it was indicated with "O". If the proportion of copper oxide on the copper surface was greater than 3%, it was indicated with "X".

[0061] [Table 1]

[0062] According to the results in Table 1, the photoresist stripping solution and method of use of the present invention can effectively remove dry film from circuit boards while maintaining the good quality of the circuit boards. According to the results of Experimental Examples 1 to 6, when a circuit board was immersed in the first stripping solution, 80% of the dry film could be removed within 180 seconds, demonstrating that the photoresist stripping solution of the present invention has a good stripping effect.

[0063] As can be seen from the results of Experimental Example 1, the effect of adding the first azole compound on the protection of the copper surface was significant. Without the addition of the first azole compound, the copper surface was corroded and easily oxidized in a strongly alkaline environment. Furthermore, the surfactant affected the stripping effect of the first stripping solution; without the addition of the surfactant, the first stripping solution could not sufficiently wet the circuit board, limiting its stripping effect.

[0064] Furthermore, if the inorganic base content in the first stripping solution is high, the film can be removed in a relatively short time. However, if the inorganic base content is too high, it may excessively corrode the substrate.

[0065] [Experimental Examples 7-12] The operating procedures and evaluation methods for Experimental Examples 7-12 and Experimental Examples 1-6 are similar; the only difference is the composition ratio of the first, second, and water components in the third stripping solution. The specific components of the first, second, and third stripping solutions are shown in Table 2. Units not specifically indicated in Table 2 are parts by weight.

[0066] [Table 2]

[0067] As can be seen from the results in Table 2, the components of the third release solution can be appropriately prepared. The lower the water content in the third release solution, the shorter the time required to peel off the film. In one exemplary embodiment, the weight ratio of water in the third release solution is 45 wt% to 75 wt%, and may also be any positive real number between 45 wt% and 75 wt%.

[0068] [Advantageous effects of the embodiment] One of the advantageous effects of the present invention is that the photoresist stripping solution and its method of use according to the present invention can have a good stripping effect without adding an organic base, due to the technical features that "the first stripping solution contains an inorganic base, a first azole compound, and a surfactant" and "the second stripping solution contains an alcohol ether solvent and a second azole compound."

[0069] Furthermore, the first stripping solution of the present invention can strip dry film over a relatively wide area, while the second and third stripping solutions can remove dry film between fine pitches. In this way, a good stripping effect is achieved without the use of organic bases, and it can replace commercially available stripping solutions that use organic bases and have a pungent odor.

[0070] Furthermore, the photoresist stripping solution of the present invention offers advantages such as ease of use for the user. The photoresist stripping solution includes a first stripping solution and a second stripping solution, which are packaged separately, thus offering advantages such as ease of use. Moreover, there is no need to add other components; a third stripping solution can be easily added simply by measuring and adding an appropriate amount of water.

[0071] The information disclosed above represents only preferred and implementable embodiments of the present invention, and the claims of the present invention are not limited thereto. Therefore, any equivalent technical modifications made using the description and drawings of the present invention are all included within the scope of the claims of the present invention. [Explanation of Symbols]

[0072] S...Circuit board B...Conveyor belt L1... The supply end of the first stripping solution. L2...Second stripping solution supply end L3... Third stripping solution supply end

Claims

1. A photoresist stripping solution comprising a first stripping solution and a second stripping solution, which are packaged separately and do not contain an organic base, The first stripping solution is An inorganic base containing potassium hydroxide and sodium hydroxide, Benzotriazole 1% to 15% by weight, Surfactant in an amount of 2% to 10% by weight, Contains water, The second stripping solution is Alcohol ether-based solvent in a concentration of 30% to 80% by weight, Benzotriazole 1% to 15% by weight, Contains water, A photoresist stripping solution characterized in that the concentration of the inorganic base in the first stripping solution is 30 g / L to 45 g / L.

2. The photoresist stripping solution according to claim 1, wherein the weight ratio of potassium hydroxide to sodium hydroxide is 2.5 to 6.

3. The photoresist stripping solution according to claim 1, wherein the surfactant is selected from the group consisting of sodium dodecyl sulfate, octadecyltrimethylammonium hydroxide, alkyldimethylphenylammonium hydroxide, alkyl sulfate salts, phosphate salts, sulfosuccinates, glutamates, lauryl betaine, cocamidopropyl betaine, and potassium polyoxyethylene lauryl ether phosphate.

4. The photoresist stripping solution according to claim 1, wherein the alcohol ether solvent is selected from the group consisting of diethylene glycol butyl ether, diethylene glycol methyl ether, diethylene glycol propyl ether, dipropylene glycol propyl ether, propylene glycol n-butyl ether, diethylene glycol dibutyl ether, tripropylene glycol methyl ether, ethylene glycol butyl ether, ethylene glycol propyl ether, diethylene glycol hexyl ether, diethylene glycol diethyl ether, and diethylene glycol dimethyl ether.

5. A method for using a photoresist stripping solution according to any one of claims 1 to 4, wherein the method for using the photoresist stripping solution is: Applying the first stripping solution to the circuit board, Applying the second stripping solution to the circuit board, A third stripping solution is prepared by mixing the first stripping solution and the second stripping solution in a weight ratio of 1:1 to 2:3 (first stripping solution: second stripping solution) and further adding 1 to 2.5 times the amount of water. This includes applying the third stripping solution to the circuit board, The first stripping solution contains no organic base, but comprises the inorganic base, 1% to 15% by weight of the benzotriazole, 2% to 10% by weight of the surfactant, and water, and the concentration of the inorganic base in the first stripping solution is 30 g / L to 45 g / L. A method for using a photoresist stripping solution, characterized in that the second stripping solution does not contain an organic base and contains 30% to 80% by weight of the alcohol ether solvent, 1% to 15% by weight of the benzotriazole, and water.

6. A method for using a photoresist stripping solution according to claim 5, wherein the first stripping solution, the second stripping solution, and the third stripping solution are applied to the circuit board by spraying.

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