Cleaning method

Abstract

To provide a cleaning method which is excellent in resin mask removability.SOLUTION: A cleaning method includes a step of peeling a resin mask from an object to be cleaned to which a resin mask is attached using a detergent composition. The detergent composition is a detergent composition containing a quaternary ammonium hydroxide (component A), amino alcohol (component B), aromatic alcohol (component C), and water (component D). A mass ratio D / C of the component D to the component C in the detergent composition is less than 10. The object to be cleaned to which the resin mask is attached is a substrate having a cured resin mask on a surface having metal wiring having a line width of a thin line part of 5 μm or more and 35 μm or less and a thickness of a thickest part of 40 μm or more and 80 μm or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a cleaning method and a method for manufacturing electronic components using the same. [Background technology]

[0002] In recent years, personal computers and various electronic devices have become increasingly power-efficient, faster, and more compact, and the wiring on the package substrates and other components they are equipped with has been getting finer every year. Until now, metal masking has been the primary method used to form such fine wiring and connection terminals such as pillars and bumps, but due to its limited versatility and the difficulty of adapting to the miniaturization of wiring, new methods are being adopted.

[0003] One new method is to use a dry film resist as a thick resin mask instead of a metal mask. This resin mask is finally peeled off and removed, and alkaline stripping cleaners are used for this purpose.

[0004] For example, Patent Document 1 describes an alkaline stripping cleaner that can simultaneously clean solder flux and dry film resist, and is characterized by adding 5 to 94% by weight of benzyl alcohol, 1 to 50% by weight of an amine compound, and 3 to 90% by weight of water relative to the total weight. The document also describes an example of a cleaning performance evaluation using a test piece in which dry film resist (70 μm thick) was attached to the surface of a silicon wafer, and openings of 150 μm in diameter were formed on the silicon wafer electrodes by exposure and development. The openings were filled with solder paste by printing and reflowing at 250°C. Patent Document 2 describes a cleaning composition for resin mask layers that can both promote removal of resin mask layers after heat treatment of solder bumps and inhibit solder corrosion, thereby improving solder connection reliability. The cleaning composition contains, per 100 parts by mass, 0.5 to 3.0 parts by mass of a specific quaternary ammonium hydroxide, 3.0 to 10.0 parts by mass of a water-soluble amine, 0.3 to 2.5 parts by mass of an acid or its ammonium salt, and 50.0 to 95.0 parts by mass of water. An example of the same document describes the production of a circuit board with solder bumps formed on it, in which the circuit board used for forming the solder bumps had 3,600 copper-surface electrodes with a diameter of 25 μm per chip, arranged at a pitch of 50 μm, and the electrodes were surrounded by a solder resist 15 μm high, higher than the electrodes. The paper then describes that a resist film is applied to the solder resist formed on the circuit board, a resin mask layer is formed, openings are formed in the resin mask layer and the solder resist on the electrodes of the circuit board by exposure and development processes, commercially available solder paste and flux are applied, the paste is heated on a hot plate at 250°C for 1 minute, and reflow is performed to form solder bumps on the electrodes of the circuit board, and the circuit board is then cut into 1 cm squares to prepare test pieces. Patent Document 3 describes a resist remover composition containing a quaternary ammonium hydroxide, an alkali metal hydroxide, an alkanolamine, a specific sulfonic acid compound, and a specific aromatic alcohol as a resist remover for removing resist on a color filter substrate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-224165 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-79244 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-157339 Summary of the Invention [Problem to be solved by the invention]

[0006] When forming fine wiring on printed circuit boards and the like, a cleaning composition is required to have high cleaning performance to reduce not only the residue of the resin mask but also the residue of auxiliary agents contained in the solder and plating solution used in forming the fine wiring and bumps. However, as wiring becomes finer, it becomes more difficult to remove resin masks from minute gaps, and cleaning compositions are therefore required to have high resin mask removal properties. Meanwhile, miniaturization of wiring is progressing in order to reduce the size, processing speed, and power consumption of electronic devices. Narrowing the wiring width increases electrical resistance, which can generate heat and lead to performance degradation of electronic devices. To reduce electrical resistance without increasing the area of ​​the wiring substrate, measures are taken to increase the height of the wiring. Therefore, the resin mask used to form the wiring becomes thicker, increasing the contact area with the wiring. Furthermore, the wiring spacing also becomes narrower as the wiring becomes finer, making the resin mask more difficult to remove. In particular, high-energy, short-wavelength light is used to draw fine wiring. However, a thick resin mask increases the distance from the resin mask surface to the substrate, resulting in a difference in the reaction rate of photopolymerization due to exposure between the surface and the surface in contact with the substrate. This causes the surface reaction to proceed excessively. Unless the penetration ability is enhanced, the cleaning composition does not penetrate through the resin mask surface, making the resin mask difficult to remove.

[0007] Therefore, the present disclosure provides a cleaning method that is excellent in removing resin masks. [Means for solving the problem]

[0008] In one aspect, the present disclosure relates to a cleaning method including a step of peeling a resin mask from an object to be cleaned to which the resin mask is attached, using a cleaning composition, wherein the cleaning composition contains a quaternary ammonium hydroxide (component A), an amino alcohol (component B), an aromatic alcohol (component C), and water (component D), the mass ratio D / C of component D to component C in the cleaning composition being less than 10, and the object to be cleaned to which the resin mask is attached is a substrate having a metal wiring with a thin line width of 5 μm or more and 35 μm or less and a maximum thickness of 40 μm or more and 80 μm or less, the substrate having a cured resin mask on a surface thereof.

[0009] In one aspect, the present disclosure relates to a method for manufacturing an electronic component, including a step of cleaning an electronic circuit board having a resin mask using the cleaning method of the present disclosure. [Effects of the Invention]

[0010] According to the present disclosure, a cleaning method that is excellent in resin mask removal performance can be provided. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1A is a photograph showing an example of the appearance of a substrate to be cleaned, FIG. 1B is a photograph showing an example of the appearance of a substrate surface after cleaning with the cleaning compositions of Examples 1 to 4, and FIG. 1C is a photograph showing an example of the appearance of a substrate surface after cleaning with the cleaning compositions of Comparative Examples 1 to 3. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present disclosure is based on the discovery that a resin mask can be efficiently removed from a substrate surface by using a cleaning composition containing a specific alkaline compound and further containing water and an aromatic alcohol in a specific mass ratio.

[0013] In one aspect, the present disclosure relates to a cleaning method (hereinafter also referred to as the "cleaning method of the present disclosure"), comprising the step of peeling a resin mask from an object to be cleaned to which the resin mask is attached, using a cleaning composition, wherein the cleaning composition is a cleaning composition containing a quaternary ammonium hydroxide (component A), an amino alcohol (component B), an aromatic alcohol (component C), and water (component D) (hereinafter also referred to as the "cleaning composition of the present disclosure"), the mass ratio D / C of component D to component C in the cleaning composition is less than 10, and the object to be cleaned to which the resin mask is attached is a substrate having a metal wiring having a thin line width of 5 μm or more and 35 μm or less and a maximum thickness of 40 μm or more and 80 μm or less, the substrate having a cured resin mask on the surface thereof.

[0014] The present disclosure provides a cleaning method that is excellent in removing resin masks. By using the cleaning method of the present disclosure to clean electronic components such as electronic circuit boards that have resin masks, high-quality electronic components can be obtained with a high yield.

[0015] Although the details of the mechanism of action by which the effects of the present disclosure are manifested are still unclear, it is presumed as follows. It is believed that the quaternary ammonium hydroxide (component A) and amino alcohol (component B) penetrate into the resin mask, promoting the dissociation of the alkali-soluble resin contained in the resin mask, and further promoting the peeling of the resin mask by causing the repulsion of the charges generated by the dissociation. Furthermore, because the quaternary ammonium hydroxide (component A) and amino alcohol (component B) have different penetration rates into the resin mask, it is believed that they suppress the rapid dissociation of the alkali-soluble resin on the surface of the resin mask, thereby suppressing the charge repulsion only on the surface of the resin mask, which inhibits penetration. On the other hand, it is believed that the aromatic alcohol (component C) penetrates into the resin mask together with the quaternary ammonium hydroxide (component A) and the amino alcohol (component B), promoting penetration and further enhancing the stripping ability of the alkali-soluble resin. Furthermore, lowering the ratio of water (component D) to aromatic alcohol (component C) (mass ratio D / C) makes it difficult for the aromatic alcohol (component C) to dissolve in the cleaning agent, dramatically facilitating penetration into the alkali-soluble resin. However, the present disclosure need not be construed as being limited to this mechanism.

[0016] In the present disclosure, a resin mask is a mask for protecting the surface of a material from treatments such as etching, plating, and heating, that is, a mask that functions as a protective film. In one or more embodiments, the resin mask may be a resist layer after exposure and development processes, a resist layer that has been subjected to at least one of exposure and development processes (hereinafter also referred to as "exposed and / or developed"), or a hardened resist layer. In one or more embodiments, the resin mask is formed using a resist whose physical properties, such as solubility in a developer, change when exposed to light, an electron beam, or the like. Resists are broadly classified into negative and positive types based on how they react with light or an electron beam. Negative resists have the property of decreasing their solubility in a developer when exposed to light, and the exposed portion of a layer containing negative resist (hereinafter also referred to as a "negative resist layer") is used as a resin mask after exposure and development. Positive resists have the property of increasing their solubility in a developer when exposed to light, and the exposed portion of a layer containing positive resist (hereinafter also referred to as a "positive resist layer") is removed after exposure and development, and the unexposed portion is used as a resin mask. By using a resin mask with such properties, fine connections on a circuit board, such as metal wiring, metal pillars, and solder bumps, can be formed. In one or more embodiments, the resin material for forming the resin mask may be a film-like photosensitive resin, a resist film, or a photoresist. A general-purpose resist film may be used.

[0017] [Peeling process] The cleaning method of the present disclosure includes a step of peeling the resin mask from an object to be cleaned to which the resin mask is attached using the cleaning composition of the present disclosure (hereinafter, also simply referred to as a "peeling step"). In one or more embodiments, the peeling step includes contacting the object to be cleaned to which the resin mask is attached with the cleaning composition of the present disclosure. According to the cleaning method of the present disclosure, the resin mask can be efficiently removed.

[0018] Examples of a method for peeling a resin mask from an object to be cleaned using the cleaning composition of the present disclosure, or a method for contacting an object to be cleaned with the cleaning composition of the present disclosure, include a method of contacting the object by immersing the object in a cleaning bath containing the cleaning composition, a method of contacting the object by spraying the cleaning composition (shower method), and an ultrasonic cleaning method in which ultrasonic waves are applied during immersion. The cleaning composition of the present disclosure can be used for cleaning as is without dilution. Examples of objects to be cleaned include the above-mentioned objects. The immersion time can be, for example, from 1 minute to 10 minutes, or even from 3 minutes to 6 minutes. The spray time can be, for example, from 1 minute to 10 minutes, or even from 3 minutes to 6 minutes.

[0019] In one or more embodiments, the cleaning method of the present disclosure may include a step of contacting an object to be cleaned with the cleaning composition, rinsing the object with water, and drying the object. Examples of the rinsing method include rinsing with running water. Examples of the drying method include air blow drying. In one or more embodiments, the cleaning method of the present disclosure may include a step of rinsing the object to be cleaned with water after contacting the object with the cleaning composition.

[0020] In the cleaning method of the present disclosure, ultrasonic waves are preferably applied when the cleaning composition of the present disclosure comes into contact with the object to be cleaned, since the cleaning power of the cleaning composition of the present disclosure can be easily exerted, and the ultrasonic waves are more preferably relatively high frequency. From the same viewpoint, the ultrasonic irradiation conditions are, for example, preferably 26 to 72 kHz and 80 to 1500 W, more preferably 36 to 72 kHz and 80 to 1500 W.

[0021] In the cleaning method of the present disclosure, the temperature of the cleaning composition is preferably 40°C or higher, more preferably 50°C or higher, from the viewpoint of making it easier for the cleaning power of the cleaning composition of the present disclosure to be exerted, and is preferably 70°C or lower, more preferably 60°C or lower, from the viewpoint of reducing the effect on organic resin-containing substrates.

[0022] [Items to be cleaned] Examples of objects to be cleaned include electronic components and their manufacturing intermediates. Examples of electronic components include at least one component selected from printed circuit boards, wafers, and metal plates such as copper plates and aluminum plates. The manufacturing intermediates are intermediate products in the manufacturing process of electronic components, including intermediate products after resin mask treatment. In one or more embodiments, the object to be cleaned having the resin mask attached thereto may be an electronic circuit board having a cured resin mask. In one or more embodiments, the object to be cleaned having a resin mask attached thereto may be a substrate having metal wiring with a fine line width of 5 μm to 35 μm and a maximum thickness of 40 μm to 80 μm, and having a cured resin mask on the surface of the substrate. Examples of the substrate include a glass epoxy multilayer substrate. Examples of the metal wiring include a metal foil such as copper foil. The metal foil may be formed by a plating process. In one or more embodiments, the substrate having metal wiring is a glass epoxy multilayer substrate having a metal foil (e.g., copper foil) on its surface. From the viewpoint of removability of the cured resin mask, the line width of the fine line portion of the metal wiring is 5 μm or more, preferably 10 μm or more, and from the same viewpoint, is 35 μm or less, preferably 30 μm or less, more preferably 20 μm or less. The thickness of the thickest part of the metal wiring (thickness of the thin line part) is 40 μm or more, preferably 45 μm or more, from the viewpoint of removability of the cured resin mask, and from the same viewpoint, is 80 μm or less, preferably 75 μm or less, more preferably 70 μm or less, and even more preferably 65 μm or less. In one or more embodiments, the object to be cleaned having a resin mask attached thereto may be an electronic component having wiring, connection terminals, or the like formed on its surface by undergoing processes such as soldering using a resin mask or plating (copper plating, aluminum plating, nickel plating, etc.). Specifically, for example, a substrate may be exemplified, in which an uncured resin mask on the surface of a glass epoxy multilayer substrate is subjected to at least one of exposure and development curing processes, the uncured resin mask is removed, and then a circuit pattern is formed by plating. A cured resin mask is present in the non-plated portions of the formed circuit pattern. Generally, the width of the cured resin mask adjacent to the fine line portion of the circuit pattern is formed to be the same as the line width of the fine line portion. From the viewpoint of removability of the cured resin mask, the width of the fine line portion formed by plating is preferably 5 μm or more, more preferably 10 μm or more, and preferably 35 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less. The thickness of the thin wire portion (plating thickness) obtained by plating is preferably 40 μm or more, more preferably 45 μm or more, from the viewpoint of removability of the cured resin mask. From the same viewpoint, it is preferably 80 μm or less, more preferably 75 μm or less, even more preferably 70 μm or less, and even more preferably 65 μm or less. The width of the cured resin mask in the non-plated portion (between the circuit patterns) is preferably 5 μm or more, more preferably 10 μm or more, from the viewpoint of removability of the cured resin mask, and is preferably 35 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less. Furthermore, from the viewpoint of exhibiting the effect of suppressing damage to the substrate resin, examples of electronic components include substrates having a resin on the surface, such as substrates having a solder resist. Therefore, in one aspect, the present disclosure relates to the use of the cleaning composition of the present disclosure as a cleaning agent in the production of electronic components.

[0023] In one or more embodiments, the cleaning method of the present disclosure can be suitably used for cleaning an object to which a resin mask or a resin mask that has been further plated and / or heated is attached, in terms of cleaning effectiveness. The resin mask may be, for example, a negative resin mask or a positive resin mask, with a negative resin mask being preferred in terms of the ease with which the effects of the present disclosure are exerted. Examples of negative resin masks include negative dry film resists that have been exposed and / or developed. In the present disclosure, a negative resin mask is formed using a negative resist, such as a negative resist layer that has been exposed and / or developed. In the present disclosure, a positive resin mask is formed using a positive resist, such as a positive resist layer that has been exposed and / or developed.

[0024] [Cleaning composition] In one or more embodiments, the cleaning composition of the present disclosure is a cleaning composition containing the following components A, B, C, and D. By using the cleaning composition of the present disclosure to clean an object to be cleaned having a resin mask attached thereto, the resin mask can be efficiently removed. Furthermore, by using the cleaning composition of the present disclosure to clean electronic components such as electronic circuit boards having a resin mask, high-quality electronic components can be obtained with a high yield. In one or more embodiments, the cleaning composition of the present disclosure can be used for cleaning an object to which a resin mask is attached. In one or more embodiments, the cleaning composition of the present disclosure can be used for removing the resin mask from an object to which the resin mask is attached. That is, in one aspect, the present disclosure relates to use of the cleaning composition of the present disclosure for removing the resin mask from an object to which the resin mask is attached.

[0025] (Component A: Quaternary ammonium hydroxide) The quaternary ammonium hydroxide (hereinafter also referred to as "Component A") contained in the cleaning composition of the present disclosure includes, for example, a quaternary ammonium hydroxide represented by the following formula (I): Component A may be one type, or two or more types may be combined. [ka]

[0026] In the above formula (I), R 1 , R 2 , R 3 and R 4 are each independently at least one selected from a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.

[0027] The quaternary ammonium hydroxide represented by formula (I) is a salt consisting of a quaternary ammonium cation and a hydroxide, and examples thereof include at least one selected from tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, 2-hydroxyethyltrimethylammonium hydroxide (choline), 2-hydroxyethyltriethylammonium hydroxide, 2-hydroxyethyltripropylammonium hydroxide, 2-hydroxypropyltrimethylammonium hydroxide, 2-hydroxypropyltriethylammonium hydroxide, 2-hydroxypropyltripropylammonium hydroxide, dimethylbis(2-hydroxyethyl)ammonium hydroxide, diethylbis(2-hydroxyethyl)ammonium hydroxide, dipropylbis(2-hydroxyethyl)ammonium hydroxide, tris(2-hydroxyethyl)methylammonium hydroxide, tris(2-hydroxyethyl)ethylammonium hydroxide, tris(2-hydroxyethyl)propylammonium hydroxide, tetrakis(2-hydroxyethyl)ammonium hydroxide, and tetrakis(2-hydroxypropyl)ammonium hydroxide. Among these, tetramethylammonium hydroxide (TMAH) is more preferable from the viewpoint of improving the removability of the resin mask.

[0028] From the viewpoint of improving resin mask removability, the content of Component A when using the cleaning composition of the present disclosure is preferably 2% by mass or more, more preferably 2.5% by mass or more, and from the same viewpoint, it is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less. From the same viewpoint, the content of Component A when using the cleaning composition of the present disclosure is preferably 2% by mass or more and 5% by mass or less, more preferably 2% by mass or more and 4% by mass or less, and even more preferably 2% by mass or more and 3% by mass or less. When Component A is a combination of two or more types, the content of Component A refers to the total content of those.

[0029] In the present disclosure, the "content of each component of the detergent composition at the time of use" refers to the content of each component at the time of cleaning, i.e., at the time when the detergent composition starts to be used for cleaning. In one or more embodiments, the content of each component in the cleaning composition of the present disclosure can be considered to be the blending amount of each component in the cleaning composition of the present disclosure.

[0030] (Component B: Amino alcohol) The amino alcohol (alkanolamine) (hereinafter also referred to as "Component B") contained in the cleaning composition of the present disclosure includes, for example, a compound represented by the following formula (II): Component B may be one type, or two or more types may be combined. [ka]

[0031] In the above formula (II), R 5 represents a hydrogen atom, a methyl group, an ethyl group, or an aminoethyl group, and R 6 represents a hydrogen atom, a hydroxyethyl group, a hydroxypropyl group, a methyl group, or an ethyl group, and R 7 represents a hydroxyethyl group or a hydroxypropyl group.

[0032] Examples of component B include at least one selected from monoethanolamine (MEA), monoisopropanolamine, N-methylmonoethanolamine, N-methylisopropanolamine, N-ethylmonoethanolamine, N-ethylisopropanolamine, diethanolamine, diisopropanolamine, N-dimethylmonoethanolamine, N-dimethylmonoisopropanolamine, N-methyldiethanolamine, N-methyldiisopropanolamine, N-diethylmonoethanolamine, N-diethylmonoisopropanolamine, N-ethyldiethanolamine, N-ethyldiisopropanolamine, N-(β-aminoethyl)ethanolamine, N-(β-aminoethyl)isopropanolamine, N-(β-aminoethyl)diethanolamine, and N-(β-aminoethyl)diisopropanolamine. Among these, monoethanolamine (MEA) is preferred from the viewpoint of improving resin mask removability.

[0033] From the viewpoint of improving resin mask removability, the content of component B when using the cleaning composition of the present disclosure is preferably 5% by mass or more, more preferably 9% by mass or more, even more preferably 10% by mass or more, and even more preferably 11% by mass or more. From the same viewpoint, the content of component B when using the cleaning composition of the present disclosure is preferably 5% by mass or more and 15% by mass or less, more preferably 9% by mass or more and 15% by mass or less, even more preferably 10% by mass or more and 14% by mass or less ... and 13% by mass or less. When component B is a combination of two or more types, the content of component B refers to the total content of those components.

[0034] From the viewpoint of improving resin mask removability, the total content of Components A and B in the cleaning composition of the present disclosure during use is preferably 7% by mass or more, more preferably 8% by mass or more, even more preferably 9% by mass or more, and even more preferably 12% by mass or more, and from the same viewpoint, it is preferably 20% by mass or less, more preferably 18% by mass or less, and even more preferably 15% by mass or less. From the same viewpoint, the total content of Components A and B in the cleaning composition of the present disclosure during use is preferably 7% by mass or more and 20% by mass or less, more preferably 8% by mass or more and 18% by mass or less, even more preferably 9% by mass or more and 18% by mass or less, and even more preferably 12% by mass or more and 15% by mass or less.

[0035] (Component C: aromatic alcohol) The aromatic alcohol (hereinafter also referred to as "Component C") contained in the cleaning composition of the present disclosure may be any compound having an aromatic ring and a hydroxyl group. From the viewpoint of improving resin mask removability, the aromatic alcohol preferably has 7 or more carbon atoms, and preferably 10 or less, more preferably 9 or less. Component C may be one type or a combination of two or more types.

[0036] Component C includes at least one selected from benzyl alcohol, phenethyl alcohol, 4-methylbenzyl alcohol, 4-ethylbenzyl alcohol, 2-phenyl-1-propanol, and 2-phenyl-2-propanol, and from the viewpoint of improving resin mask removability, benzyl alcohol is more preferred.

[0037] The content of component C in the cleaning composition of the present disclosure during use is preferably 5% by mass or more, more preferably 6% by mass or more, and even more preferably 7% by mass or more, from the viewpoint of improving resin mask removability, and is preferably 15% by mass or less, more preferably 13% by mass or less, and even more preferably 11% by mass or less, from the viewpoint of suppressing damage to the substrate resin. From the viewpoint of improving resin mask removability and suppressing damage to the substrate resin, the content of component C in the cleaning composition of the present disclosure is preferably 5% by mass or more and 15% by mass or less, more preferably 6% by mass or more and 13% by mass or less, and even more preferably 7% by mass or more and 11% by mass or less. When component C is a combination of two or more types, the content of component C refers to the total content of those components.

[0038] (Component D: water) In one or more embodiments, examples of water (hereinafter also referred to as "component D") contained in the cleaning composition of the present disclosure include ion-exchanged water, RO water, distilled water, pure water, and ultrapure water.

[0039] The content of component D in the cleaning composition of the present disclosure can be the remainder excluding components A, B, C, and the optional components described below. Specifically, the content of component D when using the cleaning composition of the present disclosure is preferably 45% by mass or more, more preferably 50% by mass or more, and even more preferably 55% by mass or more, from the viewpoints of improving resin mask removability, reducing the burden on wastewater treatment, and suppressing damage to the substrate resin. Also, from the viewpoint of improving resin mask removability, the content of component D is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less. From the same viewpoint, the content of component D when using the cleaning composition of the present disclosure is preferably 45% by mass or more and 80% by mass or less, more preferably 50% by mass or more and 75% by mass or less, and even more preferably 55% by mass or more and 70% by mass or less.

[0040] From the viewpoints of improving resin mask removability and suppressing damage to the substrate resin, the mass ratio D / C of component D to component C during use of the cleaning composition of the present disclosure is preferably less than 10 and 9.5 or less, more preferably 9 or less, and from the same viewpoint, is 1 or more, preferably 5 or more, more preferably 7 or more. From the same viewpoint, the mass ratio D / C in the cleaning composition of the present disclosure, in one or more embodiments, is preferably 1 or more and less than 10, more preferably 5 or more and 9.5 or less, and even more preferably 7 or more and 9 or less.

[0041] (Component E: organic solvent) In one or more embodiments, the cleaning composition of the present disclosure may further contain an organic solvent (hereinafter also referred to as "component E"). Component E may be one type, or two or more types may be combined. In one or more embodiments, Component E includes at least one organic solvent selected from glycol ethers and aromatic ketones. From the viewpoint of improving the removability of the resin mask, the glycol ether may be a compound having a structure in which 1 to 3 moles of ethylene glycol are added to an alcohol having 1 to 8 carbon atoms. Specific examples of glycol ethers include at least one selected from diethylene glycol monobutyl ether (BDG), ethylene glycol monobenzyl ether, diethylene glycol monohexyl ether, ethylene glycol monophenyl ether, and diethylene glycol diethyl ether. From the viewpoint of improving the removability of the resin mask, examples of the aromatic ketone include acetophenone.

[0042] When the cleaning composition of the present disclosure contains component E, the content of component E during use of the cleaning composition of the present disclosure is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, and even more preferably 2% by mass or more, from the viewpoint of improving resin mask removability. Also, from the viewpoint of improving resin mask removability, the content of component E during use of the cleaning composition of the present disclosure is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 7% by mass or less, even more preferably 5% by mass or less, and even more preferably 4% by mass or less. From the same viewpoint, the content of component E during use of the cleaning composition of the present disclosure is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 7% by mass or less, even more preferably 1% by mass or more and 5% by mass or less, and even more preferably 2% by mass or more and 4% by mass or less. When component E is a combination of two or more types, the content of component E refers to the total content of those components.

[0043] (Other ingredients) The cleaning composition of the present disclosure may further contain other components as needed in addition to the above Components A to E. Examples of other components include components that can be used in ordinary cleaning agents, such as alkaline agents other than Components A and B, amines other than Component B, surfactants, chelating agents, thickeners, dispersants, rust inhibitors, polymeric compounds, solubilizers, antioxidants, preservatives, antifoaming agents, and antibacterial agents.

[0044] In one or more embodiments, the cleaning composition of the present disclosure may be substantially free of an acid or an ammonium salt thereof. The content of the acid or the ammonium salt thereof when the cleaning composition of the present disclosure is used may be, for example, less than 0.3% by mass.

[0045] From the viewpoint of improving resin mask removability, the pH of the cleaning composition of the present disclosure during use is preferably 12 or more, more preferably 12.5 or more, and even more preferably 13 or more. In the present disclosure, the "pH during use" refers to the pH at 25°C, which can be measured using a pH meter. Specifically, it can be measured by the method described in the Examples.

[0046] (Method of producing a cleaning composition) In one or more embodiments, the cleaning composition of the present disclosure can be produced by blending the components A to D and, if necessary, the optional components described above (component E and other components) using a known method. For example, the cleaning composition of the present disclosure can be produced by blending at least the components A to D. Accordingly, the present disclosure relates to a method for producing a cleaning composition, which includes blending at least the components A to D. In the present disclosure, "blending" includes mixing the components A to D and, if necessary, the optional components described above simultaneously or in any order. In the method for producing a cleaning composition of the present disclosure, the preferred amount of each component to be blended can be the same as the preferred content of each component in the cleaning composition of the present disclosure described above.

[0047] The cleaning composition of the present disclosure may be prepared as a concentrate by reducing the amount of water (component D) to the extent that separation, precipitation, etc. do not occur and storage stability is not impaired. From the viewpoint of transportation and storage, the cleaning composition concentrate is preferably a concentrate diluted 3 times or more, and from the viewpoint of storage stability, it is preferably a concentrate diluted 30 times or less. The cleaning composition concentrate can be used by diluting it with water (component D) so that components A to D and optional components have the above-mentioned contents (i.e., contents at the time of cleaning) at the time of use. Furthermore, the cleaning composition concentrate can also be used by adding each component separately at the time of use. In the present disclosure, "at the time of use" or "at the time of cleaning" for a concentrated cleaning composition refers to the diluted state of the cleaning composition concentrate.

[0048] [Electronic component manufacturing method] In one aspect, the present disclosure relates to a method for manufacturing electronic components, including a step of peeling a resin mask from an object to be cleaned using the cleaning method of the present disclosure (peeling step). Examples of the object to be cleaned include the above-mentioned objects to be cleaned. In another aspect, the present disclosure relates to a method for producing electronic components, comprising a step of cleaning an electronic circuit board having a resin mask with the cleaning composition of the present disclosure (hereinafter also referred to as a "cleaning step"). The cleaning method in the cleaning step can be the same as the cleaning method of the present disclosure described above. According to the method for manufacturing electronic components of the present disclosure, resin masks adhering to electronic components can be effectively removed, enabling the manufacturing of highly reliable electronic components. Furthermore, by performing the cleaning method of the present disclosure, the resin masks adhering to electronic components can be easily peeled off, thereby shortening the cleaning time and improving the manufacturing efficiency of electronic components.

[0049] [kit] In one aspect, the present disclosure relates to a kit (hereinafter also referred to as the "kit of the present disclosure") for use in either the cleaning method of the present disclosure or the method for producing electronic components of the present disclosure. In one or more embodiments, the kit of the present disclosure is a kit for producing the cleaning composition of the present disclosure. The kit of the present disclosure allows for the production of a cleaning composition with excellent resin mask removal properties.

[0050] One embodiment of the kit of the present disclosure is a kit (three-liquid cleaning composition) that contains a solution containing component A (first liquid), a solution containing component B (second liquid), and a solution containing component C (third liquid) in a mutually unmixed state, and at least one selected from the first, second, and third liquids further contains part or all of component D (water), and the first, second, and third liquids are mixed at the time of use. After the first, second, and third liquids are mixed, they may be diluted with water (component D) as needed. Each of the first, second, and third liquids may contain the optional components described above as needed. Another embodiment of the kit of the present disclosure is a kit (two-liquid detergent composition) that contains a solution (first liquid) containing components A and B and a solution (second liquid) containing component C, which are not mixed with each other, and at least one of the first and second liquids further contains part or all of component D (water), and the first and second liquids are mixed at the time of use. After the first and second liquids are mixed, they may be diluted with component D (water) as needed. Each of the first and second liquids may contain the optional components described above as needed. [Example]

[0051] The present disclosure will be specifically described below using examples, but the present disclosure is not limited to these examples in any way.

[0052] 1. Preparation of cleaning compositions of Examples 1 to 4 and Comparative Examples 1 to 3 The components shown in Table 1 were blended in the amounts (mass %, active ingredient) shown in Table 1 and mixed by stirring to prepare the cleaning compositions of Examples 1 to 4 and Comparative Examples 1 to 3. The pH of each cleaning composition at 25°C shown in Table 1 was measured using a pH meter (HM-30G, manufactured by Toa Dempa Kogyo Co., Ltd.), and the value was measured one minute after the electrode of the pH meter was immersed in the cleaning composition.

[0053] The cleaning compositions of Examples 1 to 4 and Comparative Examples 1 to 3 were prepared using the following materials. (Component A) TMAH: Tetramethylammonium hydroxide [Showa Denko K.K., concentration 25%] (Component B) MEA: Monoethanolamine [Fujifilm Wako Pure Chemical Industries, Ltd., special grade] (Component C) Benzyl alcohol [Fujifilm Wako Pure Chemical Industries, Ltd., special grade] (Component D) Water [pure water of 1 μS / cm or less produced using the Organo Corporation G-10DSTSET water purification system] (Component E) BDG: Butyl diglycol [Nihon Nyukazai Co., Ltd., diethylene glycol monobutyl ether]

[0054] 2. Evaluation of the cleaning compositions of Examples 1 to 4 and Comparative Examples 1 to 3 The prepared cleaning compositions of Examples 1 to 4 and Comparative Examples 1 to 3 were evaluated as follows.

[0055] [Test piece] The test piece was 120 mm x 120 mm in size and had a fine-line circuit pattern (fine line portion) formed by copper plating on the surface of a glass epoxy multilayer substrate and a resin mask which was a hardened negative dry film resist between the formed fine-line circuit patterns. The line width of the fine-line circuit pattern (fine line portion) was 16 μm and the thickness of the fine-line portion (plating thickness) was 54 μm.

[0056] [Cleaning test method] Dipping and showering were performed consecutively as follows: 1 kg of each of the cleaning compositions of Examples 1 to 4 and Comparative Examples 1 to 4 was added to a 1-L glass beaker and heated to 50°C. The test piece was immersed for 5 minutes while stirring at 300 rpm using a rotor (fluororesin (PTFE), φ8 mm × 25 mm). A separately prepared 10-L stainless steel beaker was used as a storage tank, and 10 kg of the same cleaning composition as the 1-L glass beaker was added and heated to 50°C. The cleaning composition in the storage tank was then sprayed onto the test piece for 3 minutes (pressure: 0.1 MPa, spray distance: 10 cm) using a box-type spray washer equipped with a single-fluid nozzle (fan-shaped) VVP9060 (manufactured by Ikeuchi Co., Ltd.). The sprayed cleaning composition was collected in the storage tank and circulated for reuse. Next, the test piece was immersed in a rinsing tank containing 1 kg of water, rinsed, and then dried with nitrogen blow. Using an optical microscope "Digital Microscope VHX-2000" (manufactured by Keyence Corporation), the presence or absence of resin mask remaining on the thin line portion of the test piece after the cleaning test was visually observed at 300x magnification to check for the presence or absence of residue. Evaluation was performed based on the following evaluation criteria, and the results are shown in Table 1. <Evaluation criteria> A: No residue B: 1 to 10 residues C: There are 11 to 50 residues D: There are 51 or more residues

[0057] FIG. 1A shows an example of a photograph of the appearance of the substrate before cleaning. When the substrates (test pieces) shown in Fig. 1A were cleaned using the cleaning compositions of Comparative Examples 1 to 3, the appearance of each substrate surface after cleaning was observed, revealing resist residues, as shown in Fig. 1C. On the other hand, when the substrates were cleaned using the cleaning compositions of Examples 1 to 4, the appearance of each substrate surface after cleaning was observed, revealing no resist residues, as shown in Fig. 1B, demonstrating that the resin masks were efficiently removed.

[0058] [Table 1]

[0059] As shown in Table 1, the cleaning compositions of Examples 1 to 4 were found to be superior in resin mask removal properties compared to Comparative Example 1, which did not contain Component A, Comparative Example 2, which did not contain Component B, and Comparative Example 3, which did not contain Component C. For reference, when test pieces having a thin-line circuit pattern (thin-line portion) formed by copper plating on the surface of a glass epoxy multilayer substrate and a resin mask that is a cured negative dry film resist between the thin-line circuit patterns, where the thin-line portion had a line width of 40 μm and a plating thickness of 35 μm, were cleaned with the cleaning compositions of Example 4 and Comparative Example 3, observation of the appearance of each substrate surface after cleaning revealed no resist residue and efficient removal of the resin mask. From these results, it can be said that the cleaning compositions of the present disclosure are useful as cleaning agents for peeling off the resin mask from a substrate having a cured resin mask on the surface of a substrate with metal wiring having a thin-line portion with a line width of 5 μm to 35 μm and a maximum thickness of 40 μm to 80 μm. [Industrial Applicability]

[0060] The present disclosure provides a cleaning method that is excellent in removing resin masks. By using the cleaning method of the present disclosure, it is possible to improve the performance and reliability of manufactured electronic components, thereby improving the productivity of semiconductor devices.

Claims

1. The method includes a step of removing the resin mask from the object to be cleaned to which the resin mask is attached, using the cleaning agent composition; The cleaning composition contains a quaternary ammonium hydroxide (component A), an amino alcohol (component B), an aromatic alcohol (component C), and water (component D), The mass ratio D / C of component D to component C in the cleaning composition is less than 10, The cleaning method according to the present invention, wherein the object to be cleaned with the resin mask attached thereto is a substrate having a hardened resin mask on the surface of the substrate, the substrate having metal wiring with a line width of a thin line portion of 5 μm or more and 35 μm or less and a thickness of a thickest portion of 40 μm or more and 80 μm or less.

2. The cleaning method according to claim 1, wherein the content of component C in the cleaning agent composition is 5% by mass or more and 15% by mass or less.

3. The cleaning method according to claim 1 or 2, wherein the content of component D in the cleaning agent composition is 45% by mass or more and 80% by mass or less.

4. The cleaning method according to claim 1 or 2, wherein the content of component A in the cleaning agent composition is 2% by mass or more and 5% by mass or less.

5. The cleaning method according to claim 1 or 2, wherein the content of component B in the cleaning agent composition is 9% by mass or more and 15% by mass or less.

6. 3. The cleaning method according to claim 1, wherein the substrate having the metal wiring is a glass epoxy multi-layer substrate having a metal foil on a surface thereof.

7. The cleaning method according to claim 1 or 2, wherein component B is a compound represented by the following formula (II): 【Chemistry 1】 In the above formula (II), R 5 represents a hydrogen atom, a methyl group, an ethyl group, or an aminoethyl group; R 6 represents a hydrogen atom, a hydroxyethyl group, a hydroxypropyl group, a methyl group, or an ethyl group; R 7 represents a hydroxyethyl group or a hydroxypropyl group.

8. The cleaning method according to claim 1 or 2, wherein a mass ratio D / C of component D to component C in the cleaning agent composition is 5 or more and less than 10.

9. A method for producing electronic components, comprising the step of cleaning an electronic circuit board having a resin mask by using the cleaning method according to claim 1 or 2.

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