JP7629284B2 - Cleaning composition for removing resin masks - Google Patents

Description

This disclosure relates to a cleaning composition for removing resin masks, a method for cleaning substrates using the same, and a method for manufacturing electronic components.

In recent years, personal computers and various electronic devices have become more energy efficient, faster, and smaller, and the wiring on package boards and other devices mounted on these devices is becoming finer every year. Until now, the metal mask method has been the main method used to form such fine wiring and connection terminals such as pillars and bumps, but due to its low versatility and the difficulty of dealing with the miniaturization of wiring, etc., new methods are being used.

One new method is to use a dry film resist as a thick resin mask instead of a metal mask. This resin mask is eventually peeled off and removed, and a cleaning agent for peeling off the resin mask that contains an alkaline agent and water is known as a cleaning agent used for the peeling and removal.

For example, Patent Document 1 describes a resin mask layer cleaning agent composition that contains a specific quaternary ammonium hydroxide, a water-soluble amine, an acid or its ammonium salt, and water as a cleaning agent that can both promote removal of the resin mask layer after heat treatment of the solder bumps and inhibit solder corrosion, thereby improving solder connection reliability. In the examples, it is disclosed that ammonium carbonate is used as the ammonium salt of the acid.

JP 2015-79244 A

When forming fine wiring on printed circuit boards and the like, a cleaning composition is required to have high cleaning properties in order to reduce not only the residue of a resin mask but also the residue of auxiliary agents contained in solder, plating solution, and the like used in forming the fine wiring and bumps.
Here, the resin mask is formed using a resist whose physical properties, such as solubility in a developer, change due to light or an electron beam. Resists are broadly divided into negative and positive types based on the reaction method with light or an electron beam. A negative resist has a property that its solubility in a developer decreases when exposed to light, and the exposed part of a layer containing a negative resist (hereinafter also referred to as a "negative resist layer") is used as a resin mask after exposure and development processing. A positive resist has a property that its solubility in a developer increases when exposed to light, and the exposed part of a layer containing a positive resist (hereinafter also referred to as a "positive resist layer") is removed after exposure and development processing, and the unexposed part is used as a resin mask. By using a resin mask having such properties, fine connections of a circuit board, such as metal wiring, metal pillars, and solder bumps, can be formed.

However, as wiring becomes finer, it is becoming more difficult to remove the resin mask from the fine gaps, and cleaning compositions are required to have high resin mask removal properties. Furthermore, since corrosion of copper, which is used in many wiring and connection terminals, leads to a decrease in the quality and value of package boards, cleaning compositions are required to have high corrosion prevention capabilities. The technology disclosed in Patent Document 1 has high resin mask removal properties and solder corrosion inhibition effects, but the copper corrosion inhibition effect is insufficient.

Therefore, in one aspect, the present disclosure provides a resin mask stripping cleaning composition and a substrate cleaning method that can suppress copper corrosion without significantly impairing the removability (peelability) of the resin mask.

In one aspect, the present disclosure relates to a cleaning composition for removing resin masks, which contains a water-soluble amine (component A), at least one alkaline agent selected from a quaternary ammonium hydroxide and an alkali metal hydroxide (component B), carbonate ions (component C), and water (component D), and the concentration of component C is 0.3 mol/L or more.

In one aspect, the present disclosure relates to a cleaning composition for removing resin masks, which is a blend of a water-soluble amine (component A), at least one alkaline agent (component B) selected from a quaternary ammonium hydroxide and an alkali metal hydroxide, a carbonate (component C'), and water (component D), and the concentration of component C' is 0.3 mol/L or more.

In one aspect, the present disclosure relates to a method for cleaning a substrate, the method including a step of peeling off a resin mask from a substrate having a copper-containing metal layer and a resin mask on its surface, using a cleaning composition that contains a water-soluble amine (component A), at least one alkaline agent (component B) selected from a quaternary ammonium hydroxide and an alkali metal hydroxide, carbonate ions (component C), and water (component D), and in which the concentration of component C is 0.3 mol/L or more.

In one aspect, the present disclosure relates to a method for cleaning a substrate, the method comprising the step of peeling off a resin mask from a substrate having a copper-containing metal layer and a resin mask on its surface, using a cleaning composition comprising a water-soluble amine (component A), at least one alkaline agent (component B) selected from a quaternary ammonium hydroxide and an alkali metal hydroxide, a carbonate (component C'), and water (component D), the concentration of which is 0.3 mol/L or more.

In one aspect, the present disclosure relates to a method for cleaning a substrate, the method including a step of peeling off a resin mask from a substrate having a copper-containing metal layer and a resin mask on its surface, using a cleaning composition that contains a water-soluble amine (component A), at least one alkaline agent (component B) selected from a quaternary ammonium hydroxide and an alkali metal hydroxide, carbonate ions (component C), and water (component D), in which the amino group of component A is cationized.

In one aspect, the present disclosure relates to a method for cleaning a substrate, the method comprising the step of peeling off a resin mask from a substrate having a copper-containing metal layer and a resin mask on its surface, using a cleaning composition comprising a water-soluble amine (component A), at least one alkaline agent (component B) selected from a quaternary ammonium hydroxide and an alkali metal hydroxide, a carbonate (component C'), and water (component D) in which the amino group of component A is cationized.

In one aspect, the present disclosure relates to a method for producing electronic components, comprising the step of cleaning a substrate having a copper-containing metal layer and a resin mask on its surface using the cleaning method of the present disclosure.

According to one aspect of the present disclosure, a cleaning composition for removing resin masks can be provided that can suppress copper corrosion without significantly impairing the removability (peelability) of the resin masks.

This disclosure is based on the finding that by using a cleaning composition containing a water-soluble amine (component A), at least one alkaline agent selected from a quaternary ammonium hydroxide and an alkali metal hydroxide (component B), a predetermined concentration of carbonate ions (component C), and water (component D), or a cleaning composition for removing resin masks that is a combination of components A, B, a predetermined concentration of carbonate (component C'), and component D, it is possible to efficiently remove a resin mask from a substrate surface while suppressing copper corrosion.

In one aspect, the present disclosure relates to a cleaning composition for removing resin masks, which contains a water-soluble amine (component A), at least one alkaline agent (component B) selected from a quaternary ammonium hydroxide and an alkali metal hydroxide, carbonate ions (component C), and water (component D), and in which the concentration of component C is 0.3 mol/L or more, or a cleaning composition for removing resin masks, which is a combination of components A, B, a carbonate (component C'), and D, and in which the concentration of component C' is 0.3 mol/L or more (hereinafter, these are also collectively referred to as the "cleaning composition of the present disclosure").

According to the present disclosure, in one or more embodiments, a cleaning composition for removing a resin mask can be provided that can suppress copper corrosion without significantly impairing the removability (peelability) of the resin mask. Furthermore, by using the cleaning composition of the present disclosure, high-quality electronic components can be obtained with a high yield. Furthermore, by using the cleaning composition of the present disclosure, electronic components having fine wiring patterns can be efficiently manufactured.

Although the details of the mechanism of action by which the effects of the present disclosure are expressed are unclear, it is presumed as follows.
In the present disclosure, by using a water-soluble amine (component A) in combination with at least one alkali agent (component B) selected from quaternary ammonium hydroxides and alkali metal hydroxides, it is believed that component A and component B penetrate into the resin mask to promote dissociation of the alkali-soluble resin contained in the resin mask, and further promote peeling of the resin mask by causing repulsion of the charges generated by the dissociation. On the other hand, it is believed that the water-soluble amine (component A) is involved in etching (corrosion) of copper. Here, it is believed that a specific concentration of carbonate ions (component C) cationizes the amino group of component A, forming a complex of component A and component C, which can suppress etching of copper by component A.
However, the present disclosure need not be construed as being limited to this mechanism.

In the present disclosure, the resin mask to be peeled off and removed is a mask for protecting the surface of a material from treatments such as etching, plating, and heating, i.e., 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 steps, a resist layer that has been subjected to at least one of exposure and development (hereinafter also referred to as "exposed and/or developed"), or a hardened resist layer. In one or more embodiments, the resin material 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.

[Water-soluble amine (component A)]
The cleaning agent composition of the present disclosure contains a water-soluble amine (hereinafter, also simply referred to as "component A"). In one or more embodiments, component A may be, for example, an amine represented by the following formula (I). Component A may be one type or a combination of two or more types. In the present disclosure, "water-soluble" refers to having a solubility in water (20°C) of 0.5 g/100 mL or more, preferably a solubility of 2 g/100 mL or more.

In formula (I), R ¹ is a hydrogen atom, a hydroxyl group, a hydrocarbon group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, or an aminoalkyl group having 1 to 6 carbon atoms; R ² and R ³ are the same or different and are a hydrogen atom, a hydrocarbon group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, or an aminoalkyl group having 1 to 6 carbon atoms, and R ¹ , R ² , and R ³ are not all hydrogen atoms at the same time.

The amine represented by formula (I) includes at least one selected from monoethanolamine, monoisopropanolamine, N-methylmonoethanolamine, N-methylisopropanolamine, N-ethylmonoethanolamine, N-ethylisopropanolamine, diethanolamine, diisopropanolamine, N,N-dimethylmonoethanolamine, N-dimethylmonoisopropanolamine, N-methyldiethanolamine, N-methyldiisopropanolamine, N,N-diethylmonoethanolamine, N-diethylmonoisopropanolamine, N-ethyldiethanolamine, N-ethyldiisopropanolamine, N-(β-aminoethyl)ethanolamine, N-(β-aminoethyl)isopropanolamine, N-(β-aminoethyl)diethanolamine, N-(β-aminoethyl)diisopropanolamine, ethylenediamine, and diethylenetriamine. Among these, monoethanolamine and diethanolamine are preferred, and monoethanolamine is more preferred, from the viewpoint of improving the removability (peelability) of the resin mask.

Component A is at least one selected from monoethanolamine, N,N-diethylethanolamine, N-methylethanolamine, ethylaminoethanol, and propanediamine, from the viewpoint of inhibiting copper corrosion without significantly impairing the removability (peelability) of the resin mask, and among these, monoethanolamine is preferred.

The content of component A during use of the cleaning composition of the present disclosure is preferably 2% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more from the viewpoint of resin mask removability (peelability), and is preferably 10% by mass or less, more preferably 9% by mass or less, and even more preferably 7% by mass or less from the viewpoint of copper corrosion inhibition. More specifically, the content of component A is preferably 2% by mass or more and 10% by mass or less, more preferably 3% by mass or more and 9% by mass or less, and even more preferably 5% by mass or more and 7% 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 thereof.

In this disclosure, "the content of each component when the detergent composition is in use" refers to the content of each component at the time of cleaning, i.e., at the time when the detergent composition is first used for cleaning.

[Alkaline agent (component B)]
The cleaning composition of the present disclosure contains at least one alkaline agent selected from a quaternary ammonium hydroxide and an alkali metal hydroxide (hereinafter, also simply referred to as "Component B"). Component B may be one type or a combination of two or more types.

The quaternary ammonium hydroxide may be represented by the following formula (II).

In the above formula (II), R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent at least one group selected from a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, a hydroxyethyl group and a hydroxypropyl group.

Examples of the quaternary ammonium hydroxide represented by formula (II) include salts composed of a quaternary ammonium cation and a hydroxide. Specific examples of the quaternary ammonium hydroxide 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, from the viewpoint of improving the removability (peelability) of the resin mask, tetramethylammonium hydroxide and tetraethylammonium hydroxide are preferred, and tetramethylammonium hydroxide is more preferred.

In one or more embodiments, examples of the alkali metal hydroxide include sodium hydroxide and potassium hydroxide.

The content of Component B when using the cleaning composition of the present disclosure is preferably 0.5 mass% or more, and more preferably 3 mass% or more, from the viewpoint of resin mask removability (peelability). When Component B is a combination of two or more types, the content of Component B refers to the total content thereof.
The content of Component B during use of the cleaning composition of the present disclosure is preferably 10 mass% or less, from the viewpoint of saturating the effects of the present invention.

[Carbonate ion: (Component C)]
In one or more embodiments, the cleaning composition of the present disclosure contains carbonate ions (CO ₃ ²⁻ ) (hereinafter, also simply referred to as “component C”). In one or more other embodiments, the cleaning composition of the present disclosure contains a carbonate salt (hereinafter, also simply referred to as “component C′”) that is a source of component C. In the cleaning composition of the present disclosure, it is considered that the carbonate ions (component C) cationize the amino group of component A, thereby suppressing copper etching. Therefore, in one or more embodiments, the cleaning composition of the present disclosure is a cleaning composition that contains components A, B, C, and D, and in which the amino group of component A is cationized. In one or more other embodiments, the cleaning composition of the present disclosure is a cleaning composition that contains components A, B, C′, and D, and in which the amino group of component A is cationized.

Component C', which is the source of component C, is not particularly limited as long as it is a compound capable of supplying carbonate ions in one or more embodiments, but from the viewpoint of suppressing copper corrosion without significantly impairing the removability (peelability) of the resin mask, examples of the carbonate include alkali metal carbonates, alkaline earth metal carbonates, and quaternary ammonium carbonates. Examples of quaternary ammonium carbonates include tetraalkylammonium carbonates, specifically tetramethylammonium carbonate, and the like. The source of component C may be one type or a combination of two or more types.

The concentration (mol/L) of component C or component C' during use of the cleaning composition of the present disclosure is 0.3 mol/L or more, preferably 0.8 mol/L or more, from the viewpoint of suppressing copper corrosion without significantly impairing the removability (peelability) of the resin mask, and from the same viewpoint, is preferably 3 mol/L or less, more preferably 2 mol/L or less. More specifically, the concentration (mol/L) of component C or component C' is preferably 0.3 mol/L or more and 3 mol/L or less, more preferably 0.8 mol/L or more and 2 mol/L or less. In the present disclosure, "the concentration of each component during use of the cleaning composition" refers to the concentration of each component during cleaning, i.e., at the time when the cleaning composition is started to be used for cleaning.

The molar ratio C/A of component C to component A when using the cleaning composition of the present disclosure is preferably 0.2 or more, more preferably 0.6 or more, from the viewpoint of suppressing copper corrosion without significantly impairing the removability (peelability) of the resin mask. From the same viewpoint, it is preferably 3 or less, more preferably 2 or less. More specifically, the molar ratio C/A is preferably 0.2 or more and 3 or less, more preferably 0.6 or more and 2 or less. The molar ratio C'/A of component C' to component A when using the cleaning composition of the present disclosure can be the same as the molar ratio C/A described above.

The molar ratio C/B of component C to component B when using the cleaning composition of the present disclosure is preferably 1 or more, more preferably 1.5 or more, from the viewpoint of suppressing copper corrosion without significantly impairing the removability (peelability) of the resin mask. From the same viewpoint, it is preferably 5 or less, more preferably 3 or less. More specifically, the molar ratio C/B is preferably 1 or more and 5 or less, more preferably 1.5 or more and 3 or less. The molar ratio C'/B of component C' to component B when using the cleaning composition of the present disclosure can be the same as the molar ratio C/B described above.

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

The content of Component D in the cleaning composition of the present disclosure can be the remainder excluding Component A, Component B, Component C, and any optional components described below.
Specifically, the content of component D when the cleaning composition of the present disclosure is used is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, from the viewpoints of improving resin mask removability (peelability), inhibiting copper corrosion, reducing the load on wastewater treatment, and reducing the effect on the substrate, and from the viewpoint of improving resin mask removability (peelability), it is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less. More specifically, the content of component D when the cleaning composition of the present disclosure is used is preferably 50% by mass or more and 95% by mass or less, more preferably 60% by mass or more and 90% by mass or less, and even more preferably 70% by mass or more and 85% by mass or less.

The total amount of components A, B, C and D when using the cleaning composition of the present disclosure is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more, from the viewpoint of suppressing copper corrosion without significantly impairing the removability (peelability) of the resin mask.

[Organic solvent (component E)]
In one or more embodiments, the cleaning composition of the present disclosure may further contain an organic solvent (hereinafter, also simply referred to as "component E") from the viewpoint of improving removability (peelability) of the resin mask. Component E may be one type or a combination of two or more types.
In one or more embodiments, Component E includes at least one solvent selected from glycol ethers and aromatic ketones.
From the same viewpoint, examples of glycol ethers include compounds having a structure in which 1 to 3 moles of ethylene glycol are added to an alcohol having a carbon number of 1 to 8. 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 same viewpoint, examples of aromatic ketones include acetophenone and the like.

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 1% by mass or more, more preferably 1.5% by mass or more, and even more preferably 2% by mass or more, from the viewpoint of improving the removability (peelability) of the resin mask, and from the same viewpoint, is preferably 40% by mass or less, more preferably 20% by mass or less, and even more preferably 5% by mass or less. More specifically, the content of component E during use is preferably 1% by mass or more and 40% by mass or less, more preferably 1.5% by mass or more and 20% by mass or less, and even more preferably 2% by mass or more and 5% 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 thereof.

[Chelating agent (component F)]
In one or more embodiments, the cleaning composition of the present disclosure may further contain a chelating agent (hereinafter, also simply referred to as "Component F") from the viewpoint of improving removability (peelability) of the resin mask. Component F may be one type or a combination of two or more types.
Examples of Component F include compounds having two or more acid groups of at least one type selected from a carboxy group and a phosphonic acid group, and from the same viewpoint, compounds having preferably four or less acid groups are preferred. Specific examples of Component F in one or more embodiments include aminotrimethylenephosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, etidronic acid (1-hydroxyethane-1,1-diphosphonic acid, HEDP), and the like. Among these, from the viewpoint of reducing the environmental load, compounds not containing nitrogen atoms, such as 2-phosphonobutane-1,2,4-tricarboxylic acid and etidronic acid (HEDP), are preferred.

When the cleaning composition of the present disclosure contains component F, the content of component F during use of the cleaning composition of the present disclosure is preferably 0.5% by mass or more, more preferably 1% by mass or more, from the viewpoint of improving resin mask removability (peelability), and from the same viewpoint, is preferably 5% by mass or less, more preferably 3% by mass or less. More specifically, the content of component F during use is preferably 0.5% by mass or more and 5% by mass or less, more preferably 1% by mass or more and 3% by mass or less. When component F is a combination of two or more types, the content of component F refers to the total content thereof.

[Component G: Ammonium salt of organic acid]
In one or more embodiments, the cleaning composition of the present disclosure may further contain at least one kind of ammonium salt of an organic acid (hereinafter also referred to as "Component G") from the viewpoint of improving removability (peelability) of the resin mask. From the same viewpoint, the ammonium salt of an organic acid is preferably an ammonium salt of a carboxylic acid having 1 to 5 carbon atoms, and more preferably ammonium formate. Component G may be one kind or a combination of two or more kinds.

When the cleaning composition of the present disclosure contains component G, the content of component G during use of the cleaning composition of the present disclosure is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.3% by mass or more, from the viewpoint of improving the removability (peelability) of the resin mask, and from the same viewpoint, is preferably 2% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1% by mass or less. More specifically, the content of component G is preferably 0.1% by mass or more and 2% by mass or less, more preferably 0.2% by mass or more and 1.5% by mass or less, and even more preferably 0.3% by mass or more and 1% by mass or less. When component G is a combination of two or more types, the content of component G refers to the total content thereof.

In one or more embodiments, the cleaning composition of the present disclosure preferably further contains components E, F, and G from the viewpoint of improving the removability (peelability) of the resin mask.

[Other ingredients]
The cleaning composition of the present disclosure may further contain other components as necessary, in addition to the above-described Components A to G, within a range that does not impair the effects of the present disclosure. Examples of other components include components that can be used in ordinary cleaning agents, such as organic solvents other than Component E, surfactants, chelating agents other than Component F, thickeners, dispersants, rust inhibitors, polymeric compounds, solubilizers, antioxidants, preservatives, defoamers, and antibacterial agents.
The content of other ingredients in the cleaning composition of the present disclosure during use is preferably 0 mass% or more and 2 mass% or less, more preferably 0 mass% or more and 1.5 mass% or less, even more preferably 0 mass% or more and 1.3 mass% or less, and still more preferably 0 mass% or more and 1 mass% or less.

The total content of organic matter derived from components A, B, C and optional components (component E, component F, component G, other components) during use of the cleaning composition of the present disclosure is preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 20% by mass or less, and even more preferably 16% by mass or less, from the viewpoint of reducing the wastewater treatment load and reducing the impact on the substrate, and from the viewpoint of improving the removability (peelability) of the resin mask, it is preferably 2% by mass or more, more preferably 3% by mass or more, even more preferably 4% by mass or more, and even more preferably 6% by mass or more. More specifically, the total content of organic matter derived from components A, B, C and optional components (component E, component F, component G, other components) during use of the cleaning composition of the present disclosure is preferably 2% by mass or more and 30% by mass or less, more preferably 3% by mass or more and 25% by mass or less, even more preferably 4% by mass or more and 20% by mass or less, and even more preferably 6% by mass or more and 16% by mass or less.

[Method of producing the cleaning composition]
The cleaning composition of the present disclosure can be produced by blending a water-soluble amine (component A), at least one alkaline agent selected from a quaternary ammonium hydroxide and an alkali metal hydroxide (component B), a carbonate salt (component C') that is a source of carbonate ions (component C), water (component D), and the above-mentioned optional components (component E, component F, component G, and other components) as necessary by a known method. For example, in one or more embodiments, the cleaning composition of the present disclosure can be a composition comprising component A, component B, component C', and component D blended together.
Therefore, the present disclosure relates to a method for producing a cleaning composition, comprising a step of blending at least Component A, Component B, Component C', and Component D. In the present disclosure, "blending" includes mixing Component A, Component B, Component C', Component D, and, as necessary, the above-mentioned optional components simultaneously or in any order. In the method for producing a cleaning composition of the present disclosure, the preferred blending amount of each component may be the same as the preferred content of each component of the cleaning composition of the present disclosure described above.

The cleaning composition of the present disclosure may be in a form used for cleaning as it is, or may be prepared as a concentrate in which the amount of water (component D) is reduced to the extent that separation, precipitation, etc. do not occur and storage stability is not impaired. The concentrate of the cleaning composition is preferably a concentrate diluted 3 times or more from the viewpoint of transportation and storage, and is preferably a concentrate diluted 30 times or less from the viewpoint of storage stability. The concentrate of the cleaning composition can be used by diluting with water (component D) so that each component (component A, component B, component C, component D, component E, component F, and other components) has the above-mentioned content or concentration (i.e., content or concentration at the time of cleaning) at the time of use. Furthermore, the concentrate of the cleaning composition 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" of the concentrated cleaning composition refers to the state in which the concentrate of the cleaning composition is diluted.

[Item to be cleaned]
In one or more embodiments, the cleaning composition of the present disclosure can be used to clean a substrate having a copper-containing metal layer and a resin mask on its surface. In one or more embodiments, the copper-containing metal layer is a copper plating layer. The copper plating layer can be formed, for example, by an electroless copper plating method.
In one or more other embodiments, the cleaning composition of the present disclosure may be used to clean an object to which a resin mask is attached. In one or more embodiments, the object to be cleaned may be an object to be cleaned having a copper-containing metal site on the surface, for example, an electronic component and its manufacturing intermediate. Examples of the electronic component include at least one part selected from a printed circuit board, a wafer, and a metal plate such as a copper plate and an aluminum plate. The manufacturing intermediate is an intermediate product in the manufacturing process of an electronic component, and includes an intermediate product after a resin mask treatment.
Specific examples of objects to be cleaned with a resin mask attached include electronic components in which wiring, connection terminals, etc. are formed on the surface of a substrate by at least one of soldering and plating (copper plating, aluminum plating, nickel plating, etc.) using a resin mask. In the present disclosure, soldering refers to providing solder in a resin mask-free portion on a substrate and forming a solder bump by heating. In the present disclosure, plating refers to performing at least one plating treatment selected from copper plating, aluminum plating, and nickel plating on a resin mask-free portion on a substrate. The resin mask-free portion refers to a portion of a resist pattern formed by developing a resin mask laminated on a substrate, from which the resin mask has been removed by the development treatment. Thus, in one aspect, the present disclosure relates to the use of the cleaning composition of the present disclosure as a cleaning agent in the manufacture of electronic components.
In one or more embodiments, the object to be cleaned is a substrate having a resist pattern formed by developing a resin mask laminated on the substrate, and the substrate has undergone at least one of soldering and plating. For example, the object to be cleaned may be a substrate having a resin mask-present portion on which a cured resist layer is formed, and a solder bump or a plating layer-formed portion on which the resin mask is not present.

In one or more embodiments, the cleaning composition of the present disclosure may 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 effect. The resin mask may be, for example, a negative resin mask or a positive resin mask. In the present disclosure, a negative resin mask is formed using a negative resist, and examples of the mask include 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, and examples of the mask include a positive resist layer that has been exposed and/or developed.

[Cleaning method]
In one embodiment, the present disclosure provides a method for cleaning a substrate, the method comprising a step of peeling a resin mask from a substrate (object to be cleaned) having a copper-containing metal layer and a resin mask on its surface, by using a cleaning composition (the cleaning composition of the present disclosure) containing a water-soluble amine (component A), at least one alkaline agent (component B) selected from a quaternary ammonium hydroxide and an alkali metal hydroxide, carbonate ions (component C), and water (component D), and having a concentration of component C of 0.3 mol/L or more; and a method for removing a copper-containing metal layer and a resin mask on its surface, by using a cleaning composition containing component A, component B, a carbonate salt (component C'), and component D, and having a concentration of component C' of 0.3 mol/L or more. The present invention relates to a method for cleaning a substrate, comprising a step of peeling off a resin mask from a substrate having a metal layer and a resin mask; a method for cleaning a substrate, comprising a step (peeling step) of peeling off a resin mask from a substrate having a copper-containing metal layer and a resin mask on its surface using a cleaning composition containing components A, B, C, and D, and in which the amino group of component A has been cationized; or a method for cleaning a substrate, comprising a step of peeling off a resin mask from a substrate having a copper-containing metal layer and a resin mask on its surface using a cleaning composition containing components A, B, C', and D, and in which the amino group of component A has been cationized (hereinafter, these are also collectively referred to as the "cleaning method of the present disclosure"). Examples of the object to be cleaned include the above-mentioned object to be cleaned. In one or more embodiments, the peeling step includes contacting the object to be cleaned with the cleaning composition of the present disclosure. According to the cleaning method of the present disclosure, in one or more embodiments, the resin mask can be efficiently removed while suppressing copper corrosion. Furthermore, according to the cleaning method of the present disclosure, in one or more embodiments, the residue on the substrate after cleaning can be reduced.

Methods for peeling off a resin mask from an object to be cleaned using the cleaning composition of the present disclosure, or methods for bringing the cleaning composition of the present disclosure into contact with the object to be cleaned, include, for example, a method of bringing the object into contact by immersing the object in a cleaning bath containing the cleaning composition, a method of spraying the cleaning composition in a spray form (shower method), and an ultrasonic cleaning method of irradiating the object with ultrasonic waves 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 objects described above.

In one or more embodiments, the cleaning method of the present disclosure may include a step of contacting the object to be cleaned with the cleaning composition, rinsing with water, and drying. In one or more embodiments, the cleaning method of the present disclosure may include a step of contacting the object to be cleaned with the cleaning composition, and rinsing with water.

In the cleaning method of the present disclosure, it is preferable to irradiate ultrasonic waves when the cleaning composition of the present disclosure comes into contact with the object to be cleaned, since this makes it easier for the cleaning power of the cleaning composition of the present disclosure to be exerted, and it is more preferable that the ultrasonic waves have a relatively high frequency. From the same viewpoint, the ultrasonic irradiation conditions are, for example, preferably 26 to 72 kHz and 80 to 1500 W, and more preferably 36 to 72 kHz and 80 to 1500 W.

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, in order to facilitate the cleaning power of the cleaning composition of the present disclosure, and is preferably 70°C or lower, more preferably 60°C or lower, in order to reduce the effect on the substrate.

[Electronic component manufacturing method]
In one aspect, the present disclosure relates to a method for producing an electronic component (hereinafter also referred to as the "method for producing an electronic component of the present disclosure"), which includes a step (cleaning step) of cleaning a substrate (object to be cleaned) having a copper-containing metal layer and a resin mask on its surface using the cleaning method of the present disclosure. Examples of the object to be cleaned include the above-mentioned objects to be cleaned. In one or more embodiments, the method for producing an electronic component of the present disclosure can include a step of etching the copper-containing metal layer after the cleaning step.
According to the manufacturing method of electronic components of the present disclosure, by performing cleaning using the cleaning method of the present disclosure, it is possible to effectively remove the resin mask attached to the electronic components while suppressing copper corrosion, and further to reduce the amount of residue on the substrate after cleaning, thereby enabling the manufacturing of highly reliable electronic components. Furthermore, by performing cleaning using the cleaning method of the present disclosure, it is possible to easily remove the resin mask attached to the electronic components, thereby shortening the cleaning time and improving the manufacturing efficiency of electronic components.

[kit]
In one aspect, the present disclosure relates to a kit for use in any one of the cleaning method of the present disclosure and the method for producing an electronic component of the present disclosure (hereinafter, also referred to as the "kit 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. According to the kit of the present disclosure, a cleaning composition capable of suppressing copper corrosion can be obtained without significantly impairing the removability (peelability) of a resin mask.

One embodiment of the kit of the present disclosure includes a kit (three-liquid type cleaning agent composition) that includes a solution (first liquid) containing component A, a solution (second liquid) containing component B, and a solution (third liquid) containing component C or component C' in a mutually unmixed state, and at least one selected from the first liquid, the second liquid, and the third liquid further contains a part or all of water (component D), and the first liquid, the second liquid, and the third liquid are mixed at the time of use. After the first liquid, the second liquid, and the third liquid are mixed, they may be diluted with water (component D) as necessary. Each of the first liquid, the second liquid, and the third liquid may contain the above-mentioned optional components as necessary.
Other embodiments of the kit of the present disclosure include a kit (two-liquid type cleaning agent composition) that includes a solution (first liquid) containing component B and a solution (second liquid) containing component A and component C or component C' in a mutually unmixed state, at least one of the first liquid and the second liquid further contains a part or all of water (component D), and the first liquid and the second liquid are mixed at the time of use. After the first liquid and the second liquid are mixed, they may be diluted with water (component D) as necessary. Each of the first liquid and the second liquid may contain the above-mentioned optional components as necessary.

The present disclosure will be explained in detail below with reference to examples, but the present disclosure is not limited to these examples.

1. Preparation of cleaning agent compositions of Examples 1 to 8 and Comparative Examples 1 and 2 The cleaning agent compositions of Examples 1 to 8 and Comparative Examples 1 and 2 were prepared by blending the components shown in Table 1 in the blending amounts (mass %, active content) shown in Table 1 and stirring to mix. Table 1 shows the concentrations (mol/L) of Components A to C, the molar ratio C/A of carbonate ion/water-soluble amine, and the molar ratio C/B of carbonate ion/alkali agent in each of the prepared cleaning agent compositions.

The following materials were used to prepare the cleaning compositions of Examples 1 to 8 and Comparative Examples 1 and 2.
(Component A)
MEA: Monoethanolamine [manufactured by Nippon Shokubai Co., Ltd.]
(Component B)
TMAH: Tetramethylammonium hydroxide [manufactured by Showa Denko K.K., concentration 25%]
(Source of Component C (Component C'))
Tetramethylammonium carbonate [pH: 9.3, manufactured by Osaka Chemical Industries, Ltd., concentration 30%]
Ammonium carbonate [manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.]
(Component D)
Water [pure water of 1 μS/cm or less produced using the Organo Corporation pure water system G-10DSTSET]
(Component E)
BDG: Butyl diglycol [Nihon Nyukazai Co., Ltd., diethylene glycol monobutyl ether]
(Component F) HEDP: Etidronic acid [manufactured by Italmatch Japan Co., Ltd., Dequest 2010, concentration 60%]
(Component G)
Ammonium formate [Toyama Pharmaceutical Co., Ltd.]

2. Evaluation of the Cleaning Compositions The cleaning compositions prepared in Examples 1 to 8 and Comparative Examples 1 and 2 were evaluated as follows.

[Preparation of test pieces]
A photosensitive film for forming a PKG (semiconductor package) board circuit was laminated on the surface of the board after electroless plating under the following conditions, and then exposed to light to cure (exposure step) to obtain a board having a resin mask (test piece, 30 mm x 50 mm).
(1) Lamination: Using a clean roller (RY-505Z, manufactured by Rayon Kogyo Co., Ltd.) and a vacuum applicator (VA7024/HP5, manufactured by Rohm and Haas Co.), the roller temperature was 50° C. and the roller pressure was 1.4 Bar.
(2) Exposure: Exposure is performed using a direct imaging device for printed circuit boards (Mercurex LI-9500, manufactured by SCREEN Graphic and Precision Solutions Co., Ltd.) at an exposure dose of 15 mJ/ ^cm2 .

[Cleaning test]
100 g of each of the cleaning compositions of Examples 1 to 8 and Comparative Examples 1 and 2 was added to a tall 200 mL glass beaker and heated to 50° C. The test piece was immersed for 10 minutes in a state where it was stirred at 600 rpm using a rotor (fluororesin (PTFE), φ8 mm × 25 mm). Then, the test piece was rinsed by immersing it in a rinsing tank containing a 100 mL glass beaker with 100 g of water, and then dried by nitrogen blow.

[Evaluation of Resin Mask Removability (Strippability)]
Using an optical microscope "Digital Microscope VHX-6000" (manufactured by Keyence Corporation), the presence or absence of the resin mask remaining on the pattern portion of the test piece after the cleaning test is visually confirmed at 500 times magnification, and evaluated according to the following criteria.
<Evaluation criteria>
A: No residues are observed even at 5 μm/5 μm. B: No residues are observed up to 6 μm/6 μm. C: No residues are observed up to 7 μm/7 μm. D: Residues are observed even at 7 μm/7 μm.

[Evaluation of Cu Etching Rate (Evaluation of Copper Corrosion)]
2.5 L of each cleaning composition was prepared and heated to 50°C. The composition was circulated in a box-type spray washer equipped with a full-cone nozzle (J020, manufactured by Ikeuchi Co., Ltd.) as a spray nozzle, and sprayed for 4 minutes (pressure: 0.05 MPa, spray distance: 80 mm) onto a test piece whose surface was copper-plated (area: 25 ^cm2 per side, 50 ^cm2 on both sides). After diluting the cleaning composition, the amount of copper eluted was measured by ICP analysis (Agilent5110 ICP-OES manufactured by Agilent Technologies), and the Cu etching rate (μm/min) was evaluated from the amount of elution, assuming a copper density of 8.94 g/ ^cm3 , according to the following formula. It can be determined that the lower the Cu etching rate, the better the copper corrosion inhibition effect.
Cu etching rate (μm/min) = copper elution amount (weight) ÷ copper density ÷ plating area ÷ treatment time

[Evaluation of damage to board resin]
The above cleaning test is carried out on a board having a solder resist resin, and whether there is any change in color or the like in the resin part of the board before and after the test is visually confirmed and evaluated according to the following evaluation criteria.
<Evaluation criteria>
A: No change was observed before and after the cleaning test.
B: A change was observed before and after the cleaning test.

As shown in Table 1, the cleaning compositions of Examples 1 to 8 were able to suppress copper corrosion without significantly impairing the removability (peelability) of the resin mask, compared to Comparative Example 1 which did not contain Component C and Comparative Example 2 which contained Component C at a concentration of less than 0.3 mol/L.
In addition, when Comparative Example 1 (pH 12), which contains only MEA (component A) and TMAH (component B) other than water, is compared with Example 1 (pH 11), which further contains tetramethylammonium carbonate, it was found that, although the pH of Example 1 is decreased by the incorporation of tetramethylammonium carbonate, the content of TMAH measured by neutralization titration is the same between the two. Therefore, it is considered that the reason for the decrease in pH of Example 1 is due to the decrease in the content of MEA. From this, it was presumed that tetramethylammonium carbonate cationizes the amino group of MEA in Example 1. Here, the pH is the pH of the cleaning composition at 25° C., and is measured using a pH meter (Toa Denpa Kogyo Co., Ltd., HM-30G), and is the value 3 minutes after immersing the electrode in the cleaning composition.

According to the present disclosure, a cleaning composition can be provided that can suppress copper corrosion without significantly impairing the removability of the resin mask. By using the cleaning composition of the present disclosure, it is possible to shorten the cleaning process for electronic components with a resin mask attached and improve the performance and reliability of the manufactured electronic components, thereby improving the productivity of semiconductor devices.

Claims (13)

A cleaning composition for stripping a resin mask from a substrate having a copper-containing metal layer and a resin mask on a surface thereof, comprising:
The composition contains a water-soluble amine (component A), at least one alkaline agent (component B) selected from a quaternary ammonium hydroxide and an alkali metal hydroxide represented by the following formula (II), a carbonate ion (component C), and water (component D),
The concentration of component C is 0.3 mol/L or more,
A cleaning composition for stripping a resin mask , wherein a molar ratio C/B of component C to component B during use of the cleaning composition is 1 or more and 5 or less .

In the above formula (II), R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent at least one group selected from a methyl group, an ethyl group and a propyl group. A cleaning composition for stripping a resin mask from a substrate having a copper-containing metal layer and a resin mask on a surface thereof, comprising:
The composition comprises a water-soluble amine (component A), at least one alkaline agent (component B) selected from a quaternary ammonium hydroxide and an alkali metal hydroxide represented by the following formula (II), a carbonate (component C'), and water (component D),
The concentration of component C' is 0.3 mol/L or more,
A cleaning composition for stripping a resin mask , wherein a molar ratio C'/B of component C' to component B during use of the cleaning composition is 1 or more and 5 or less .

In the above formula (II), R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent at least one group selected from a methyl group, an ethyl group and a propyl group. 3. The cleaning composition for stripping a resin mask according to claim 1, wherein component A is an amine represented by the following formula (I):

In formula (I), R ¹ is a hydrogen atom, a hydroxyl group, a hydrocarbon group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, or an aminoalkyl group having 1 to 6 carbon atoms; R ² and R ³ are the same or different and are a hydrogen atom, a hydrocarbon group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, or an aminoalkyl group having 1 to 6 carbon atoms, and R ¹ , R ² , and R ³ are not all hydrogen atoms at the same time. The cleaning composition according to any one of claims 1 to 3, wherein the content of component D is 50% by mass or more and 95% by mass or less. The cleaning composition according to claim 1 , wherein the total amount of component A, component B, component C and component D is 80 mass% or more. A method for cleaning a substrate, the method comprising: removing a resin mask from a substrate having a copper-containing metal layer and a resin mask on a surface thereof, by using a cleaning composition comprising a water-soluble amine (component A), at least one alkaline agent (component B) selected from a quaternary ammonium hydroxide represented by the following formula (II) and an alkali metal hydroxide, carbonate ions (component C) and water (component D), wherein the concentration of component C is 0.3 mol/L or more and a molar ratio C/B of component C to component B during use is 1 or more and 5 or less:

In the above formula (II), R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent at least one group selected from a methyl group, an ethyl group and a propyl group. A method for cleaning a substrate, comprising: a step of stripping a resin mask from a substrate having a copper-containing metal layer and a resin mask on a surface thereof, using a cleaning composition comprising a water-soluble amine (component A), at least one alkaline agent (component B) selected from a quaternary ammonium hydroxide and an alkali metal hydroxide represented by the following formula (II), a carbonate (component C'), and water (component D), wherein the concentration of component C' is 0.3 mol/L or more and the molar ratio C'/B of component C' to component B during use is 1 or more and 5 or less:

In the above formula (II), R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent at least one group selected from a methyl group, an ethyl group and a propyl group. The method includes a step of removing a resin mask from a substrate having a copper-containing metal layer and a resin mask on a surface thereof, by using a cleaning composition comprising a water-soluble amine (component A), at least one alkaline agent (component B) selected from a quaternary ammonium hydroxide and an alkali metal hydroxide represented by the following formula (II), carbonate ions (component C) and water (component D), in which an amino group of component A is cationized ,
The method for cleaning a substrate , wherein a molar ratio C/B of component C to component B during use of the cleaning composition is 1 or more and 5 or less .

In the above formula (II), R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent at least one group selected from a methyl group, an ethyl group and a propyl group. The method includes a step of removing a resin mask from a substrate having a copper-containing metal layer and a resin mask on a surface thereof, by using a cleaning composition comprising a water-soluble amine (component A), at least one alkaline agent (component B) selected from a quaternary ammonium hydroxide and an alkali metal hydroxide represented by the following formula (II), a carbonate (component C'), and water (component D), in which an amino group of component A is cationized ,
The method for cleaning a substrate , wherein a molar ratio C'/B of component C' to component B during use of the cleaning composition is 1 or more and 5 or less .

In the above formula (II), R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent at least one group selected from a methyl group, an ethyl group and a propyl group. The cleaning method according to any one of claims 6 to 9 , wherein the copper-containing metal layer is a copper plating layer. 11. The cleaning method according to claim 6 , wherein the resin mask is a hardened resist layer. The cleaning method according to any one of claims 6 to 11 , wherein the total amount of component A, component B, component C and component D at the time of using the cleaning agent composition is 80 mass% or more. A method for producing an electronic component, comprising the step of cleaning a substrate having a copper-containing metal layer and a resin mask on a surface thereof, by using the cleaning method according to any one of claims 6 to 12 .