TWI865770B - Method for cleaning substrate - Google Patents

Abstract

The present invention provides, in one aspect, a cleaning method that has excellent resin mask removal performance and can inhibit copper corrosion and discoloration. The present invention relates to a substrate cleaning method in one aspect, which includes the step of using a cleaning agent composition to remove a resin mask from a substrate having a copper-containing metal layer and a resin mask on its surface, wherein the cleaning agent composition contains an alkali (component A), ammonium ions (NH ₄ ⁺ , component B), thioglycolic acid (component C) and water (component D), and the molar ratio of component B to component C (B/C) is greater than 1.5.

Description

Substrate cleaning method

The present invention relates to a cleaning agent composition for resin mask stripping, a method for cleaning a substrate using the same, and a method for manufacturing electronic components.

In recent years, personal computers and various electronic devices have been developing towards low power consumption, high processing speed, and miniaturization, and the wiring of the package substrates they carry has also been advancing year by year. Previously, in order to form such fine wiring and connecting terminals such as pillars or bumps, the metal mask method was mainly used, but due to its low versatility or difficulty in coping with the miniaturization of wiring, it is now shifting to other new methods.

As one of the new methods, a method is known in which a dry film resist is used instead of a metal mask to form a thick film resin mask. The resin mask will eventually be peeled off and removed, and as a cleaning agent used in the cleaning operation such as peeling off and removing, a cleaning agent for peeling off the resin mask containing an alkali and water is known.

For example, in Japanese Patent Publication No. 2014-78009 (Patent Document 1), there is a composition containing alkanolamine, organic solvent, water, hydroxide, and anti-corrosion agent, which can effectively remove the film and anti-corrosion agent without damaging the substrate structure under the thick film and anti-corrosion agent. Japanese Patent Publication No. 2015-79244 (Patent Document 2) describes a resin mask cleaning agent composition containing a specific quaternary ammonium hydroxide, a water-soluble amine, an acid or its ammonium salt, and water. The resin mask cleaning agent composition is used as a cleaning agent to promote the removal of the resin mask layer after the heat treatment of the solder bump, inhibit solder corrosion, and improve the reliability of solder connection.

The present invention, in one aspect, relates to a method for cleaning a substrate, comprising the step of stripping a resin mask from a substrate having a copper-containing metal layer and a resin mask on its surface using a cleaning agent composition, wherein the cleaning agent composition contains an alkali (component A), ammonium ions (NH ₄ ⁺ , component B), thioglycolic acid (component C) and water (component D), and the molar ratio of component B to component C (B/C) is greater than 1.5.

The present invention in one aspect relates to a method for manufacturing an electronic component, which includes a step of stripping a resin mask from a substrate having a copper-containing metal layer and a resin mask on its surface using the cleaning method of the present invention.

In one aspect, the present invention relates to a cleaning agent composition for removing resin masks, which contains an alkali (component A), ammonium ions (NH ₄ ⁺ , component B), thioglycolic acid (component C) and water (component D), and the molar ratio of component B to component C (B/C) is greater than 1.5.

In one embodiment, the present invention relates to the use of a cleaning agent composition, which is to use the cleaning agent composition to clean a substrate having a copper-containing metal layer and a resin mask on the surface. The cleaning agent composition contains an alkali (component A), ammonium ions (NH ₄ ⁺ , component B), thioglycolic acid (component C) and water (component D), and the molar ratio of component B to component C (B/C) is greater than 1.5.

After forming fine wiring on a printed circuit board, etc., in order to reduce the residue of the resin mask and the residue of the additives contained in the solder or plating liquid used to form the fine wiring or bumps, the cleaning agent composition is required to have high cleaning properties. Here, the so-called resin mask is formed using an anti-etching agent, and the physical properties of the anti-etching agent such as solubility in the developer will change due to light or electron beams. Anti-etching agents are generally divided into negative type and positive type according to their reaction method with light or electron beams. Negative resist has the property that its solubility in the developer decreases when exposed. After exposure and development, the exposed part of the layer containing negative resist (hereinafter also referred to as "negative resist") is used as a resin mask. Positive resist has the property that its solubility in the developer increases when exposed. After exposure and development, the exposed part of the layer containing positive resist (hereinafter also referred to as "positive resist") is removed and the unexposed part is used as a resin mask. By using a resin mask with such a property, fine connection parts of circuit boards such as metal wiring, metal columns or solder bumps can be formed. The resin mask must be removed after the fine wiring or bumps are formed.

However, as the wiring becomes more miniaturized, it becomes difficult to remove the resin mask in the fine gaps, and the cleaning agent composition is required to have a higher resin mask removal performance. Furthermore, the corrosion or discoloration of the copper commonly used in wiring or connecting terminals will lead to a decrease in the quality and value of the package substrate. Therefore, the cleaning agent composition is required to have a higher corrosion resistance and anti-discoloration ability. In addition, it is known that the discoloration of copper is caused by, for example, the generation of sulfides on the copper surface. When a copper removal step (such as a seed etching step) is performed after the cleaning step, it is difficult to remove the discolored copper.

Therefore, the present invention provides, in one aspect, a substrate cleaning method and a cleaning agent composition for removing the resin mask, which have excellent resin mask removal performance and can inhibit copper corrosion and discoloration.

The present invention is based on the insight that by using a cleaning composition comprising ammonium ions and thioglycolic acid in a specific molar ratio, copper corrosion can be inhibited and resin mask can be efficiently removed from the substrate surface.

The present invention, in one embodiment, relates to a method for cleaning a substrate (hereinafter also referred to as the "cleaning method of the present invention"), which includes the step of stripping a resin mask from a substrate having a copper-containing metal layer and a resin mask on its surface using a cleaning agent composition (hereinafter also referred to as the "cleaning agent composition of the present invention"). The cleaning agent composition contains an alkali (component A), ammonium ions ( _NH4 ⁺ , component B), thioglycolic acid (component C) and water (component D), and the molar ratio of component B to component C (B/C) is greater than 1.5.

According to the present invention, a cleaning method can be provided which has excellent resin mask removal performance and can suppress copper corrosion and discoloration. Furthermore, by using the cleaning method of the present invention, high-quality electronic components can be obtained with high yield. Furthermore, by using the cleaning method of the present invention, electronic components with fine wiring patterns can be manufactured efficiently.

The detailed mechanism of action of the effect of the present invention is unclear, but it is presumed as follows. It is believed that the alkaline agent will penetrate into the resin mask, promote the dissociation of the alkaline-soluble resin formulated in the resin mask, and then induce the charge repulsion generated by the dissociation, thereby promoting the peeling of the resin mask, thereby improving the removability of the resin mask. On the other hand, it is believed that the alkaline agent will participate in the etching (corrosion) of copper. Although thioglycolic acid is believed to inhibit the etching of copper by the alkaline agent, it will form a salt with copper and cause the copper to discolor. It is believed that in a detergent composition containing water, by combining ammonium ions and thioglycolic acid at a specific ratio, the excess presence of ammonium ions relative to thioglycolic acid will inhibit the formation of copper salt of thioglycolic acid, and copper etching (corrosion) inhibition and good stripping performance can be exhibited in the presence of an alkali, and copper discoloration can be inhibited. However, the present invention is not limited to this mechanism for interpretation.

The resin mask that is to be peeled off and removed in the present invention is a mask used to protect the surface of the material from being affected by etching, plating, heating and other treatments, that is, a mask that functions as a protective film. As the resin mask, in one or more embodiments, an anti-etching layer after exposure and development steps, an anti-etching layer that has been subjected to at least one treatment of exposure and development (hereinafter also referred to as "exposed and/or developed"), or a hardened anti-etching layer can be cited. As the resin material for forming the resin mask, in one or more embodiments, a film-like photosensitive resin, an anti-etching film, or a photoresist can be cited. The anti-etching film can be a general-purpose one.

[Cleaning agent composition] The cleaning agent composition of the present invention is a cleaning agent composition for resin mask stripping in one or more embodiments, which contains an alkali (component A), ammonium ions (component B), thioglycolic acid (component C) and water (component D), and the molar ratio of component B to component C (B/C) is 1.5 or more. According to the cleaning agent composition of the present invention, in one or more embodiments, copper corrosion inhibition and good resin mask stripping performance can be exhibited, and copper discoloration can be inhibited. According to the cleaning agent composition of the present invention, in one or more embodiments, the resin mask in the fine gap can be efficiently peeled off and removed. According to the cleaning agent composition of the present invention, in one or more embodiments, damage to the substrate resin can be suppressed. As the substrate resin, for example, solder resist can be cited.

[Alkali (Component A)] The alkali (hereinafter also referred to as "Component A") contained in the detergent composition of the present invention may be, in one or more embodiments, at least one selected from inorganic alkalis and organic alkalis. From the perspective of reducing the wastewater treatment load, inorganic alkalis are preferred. Component A may be one or a combination of two or more.

As the inorganic base, in one or more embodiments, hydroxides, carbonates or silicates of alkali metals or alkali earth metals can be exemplified, and specifically, at least one selected from sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, sodium silicate and potassium silicate can be exemplified. Among them, from the viewpoint of improving the resin mask removal property, one or a combination of two or more selected from sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate is preferred, at least one of sodium hydroxide and potassium hydroxide is more preferred, and potassium hydroxide is further preferred. In the present invention, the inorganic base does not include ammonia (NH ₃ ) and ammonium ions (NH ₄ ⁺ ).

As the organic base, in one or more embodiments, tetraalkylammonium hydroxide, organic amine, etc. can be exemplified. As the tetraalkylammonium hydroxide, for example, quaternary ammonium hydroxide represented by the following formula (I) can be exemplified. As the organic amine, for example, amine represented by the following formula (II) can be exemplified. As component A, in one or more embodiments, from the viewpoint of improving the resin mask removal property, it is preferred to use a combination of a quaternary ammonium hydroxide represented by formula (I) and an amine represented by formula (II).

[Chemistry 1]

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

[Chemistry 2]

In the above formula (II), R ⁵ represents a hydrogen atom, a methyl group, an ethyl group or an aminoethyl group, R ⁶ is at least one selected from a hydrogen atom, a hydroxyethyl group, a hydroxypropyl group, a methyl group or an ethyl group, and R ⁷ is at least one selected from an aminoethyl group, a hydroxyethyl group or a hydroxypropyl group, or in formula (II), R ⁵ is at least one selected from a methyl group, an ethyl group, an aminoethyl group, a hydroxyethyl group or a hydroxypropyl group, and R ⁶ and R ⁷ are bonded to each other and form a pyrrolidine ring or a piperidine ring together with the N atom in formula (II).

Examples of the quaternary ammonium hydroxide represented by formula (I) include salts containing quaternary ammonium cations and hydroxides. Specific examples of the quaternary ammonium hydroxide include tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, 2-hydroxyethyltrimethylammonium hydroxide (choline), 2-hydroxyethyltriethylammonium hydroxide, 2-hydroxyethyltripropylammonium hydroxide, 2-hydroxypropyltrimethylammonium hydroxide, 2-hydroxypropyltriethylammonium hydroxide, 2-hydroxypropyl ...methylammonium hydroxide, 2-hydroxypropyltriethylammonium hydroxide, 2-hydroxypropyltripropylammonium hydroxide, 2-hydroxypropyltrimethylammonium hydroxide, 2-hydroxypropyltrimethylammonium hydroxide, 2-hydroxypropyltrimethylammonium hydroxide, 2-hydroxypropyltrimethylammonium hydroxide, 2-hydroxypropyltrimethylammonium hydroxide, 2 At least one of ammonium hydroxide, dimethylbis(2-hydroxyethyl)ammonium hydroxide, diethylbis(2-hydroxyethyl)ammonium hydroxide, dipropylbis(2-hydroxyethyl)ammonium hydroxide, tri(2-hydroxyethyl)methylammonium hydroxide, tri(2-hydroxyethyl)ethylammonium hydroxide, tri(2-hydroxyethyl)propylammonium hydroxide, tetra(2-hydroxyethyl)ammonium hydroxide, and tetra(2-hydroxypropyl)ammonium hydroxide is used. Among them, from the viewpoint of improving the resin mask removal property, tetramethylammonium hydroxide and tetraethylammonium hydroxide are preferred, and tetramethylammonium hydroxide is more preferred.

Examples of the amine represented by formula (II) include alkanolamines, mono- to tri-amines, and heterocyclic compounds. Specific examples of the amine include those selected from monoethanolamine, monoisopropanolamine, N-methylmonoethanolamine, N-methylisopropanolamine, N-ethylmonoethanolamine, N-ethylisopropanolamine, diethanolamine, diisopropanolamine, N-dimethylmonoethanolamine, N-dimethylmonoisopropanolamine, N-methyldiethanolamine, N-methyldiisopropanolamine, N-diethylmonoethanolamine, N-diethylmonoisopropanolamine, At least one of propanolamine, N-ethyldiethanolamine, N-ethyldiisopropanolamine, N-(β-aminoethyl)ethanolamine, N-(β-aminoethyl)isopropanolamine, N-(β-aminoethyl)diethanolamine, N-(β-aminoethyl)diisopropanolamine, 1-methylpiperidinium, 1-(2-hydroxyethyl)pyrrolidine, 1-(2-hydroxyethyl)piperidinium, ethylenediamine and diethylenetriamine. Among them, monoethanolamine and diethanolamine are preferred from the viewpoint of improving the removability of the resin mask, and monoethanolamine is more preferred.

From the viewpoint of improving the resin mask removal and inhibiting copper corrosion, the content of component A when using the cleaning agent composition of the present invention is preferably 0.5 mass % or more, more preferably 2 mass % or more, and, from the same viewpoint, preferably 8 mass % or less, more preferably 6 mass % or less. More specifically, when using the cleaning agent composition of the present invention, the content of component A is preferably 0.5 mass % or more and 8 mass % or less, more preferably 2 mass % or more and 6 mass % or less. In the case where component A is a combination of two or more, the content of component A refers to the total content thereof.

The "content of each component when the detergent composition is used" in the present invention refers to the content of each component at the time of cleaning, that is, the time when the detergent composition is started to be used for cleaning.

[Ammonium ions: NH ₄ ⁺ (Component B)] The ammonium ions contained in the cleaning agent composition of the present invention (hereinafter also referred to as "Component B") are ammonium ions represented by the chemical formula NH ₄ ⁺ . As a supply source of Component B, in one or more embodiments, there is no particular limitation as long as it is a compound that can supply ammonium ions (NH ₄ ⁺ ). From the perspective of resin mask removal and inhibition of copper corrosion, at least one of ammonia and an ammonium salt of an organic acid can be exemplified. Ammonia can also be used in a gaseous form, but from the perspective of workability, it is preferably used in the form of an aqueous solution (ammonia water). As an ammonium salt of an organic acid, for example, an ammonium salt of thioglycolic acid (Component C) can be exemplified. From the viewpoint of resin mask removal and copper corrosion inhibition, the supply source of component B is preferably a combination of ammonia and an ammonium salt of thioglycolic acid (component C), or a combination of ammonia and an ammonium salt of a carboxylic acid.

From the viewpoint of improving the resin mask removal property and inhibiting copper corrosion, when the cleaning agent composition of the present invention is used, the content (mol/100 g) of component B relative to 100 g of the cleaning agent composition is preferably 0.02 mol/100 g or more, more preferably 0.04 mol/100 g or more, and, from the same viewpoint, is preferably 0.08 mol/100 g or less, more preferably 0.06 mol/100 g or less. More specifically, when the cleaning composition of the present invention is used, the content (mol/100 g) of component B relative to 100 g of the cleaning composition is preferably 0.02 mol/100 g to 0.08 mol/100 g, and more preferably 0.04 mol/100 g to 0.06 mol/100 g.

[Thioglycolic acid (ingredient C)] As a supply source of thioglycolic acid (ingredient C) contained in the detergent composition of the present invention, thioglycolic acid or its salt can be cited. For example, ammonium salt of thioglycolic acid can be a supply source of ingredient B and ingredient C. For example, monoethanolamine thioglycolic acid can be a supply source of ingredient A and ingredient C.

From the viewpoint of improving the resin mask removal and inhibiting copper corrosion, the content (mass%) of thioglycolic acid (hereinafter also referred to as "component C") when using the cleaning agent composition of the present invention is preferably 0.5 mass% or more, more preferably 1 mass% or more, and, from the same viewpoint, preferably 3 mass% or less, more preferably 2 mass% or less. More specifically, when using the cleaning agent composition of the present invention, the content of component C is preferably 0.5 mass% or more and 3 mass% or less, more preferably 1 mass% or more and 2 mass% or less.

From the viewpoint of improving the resin mask removal property and inhibiting copper corrosion, when the cleaning agent composition of the present invention is used, the content (mol/100 g) of component C relative to 100 g of the cleaning agent composition is preferably 0.005 mol/100 g or more, more preferably 0.01 mol/100 g or more, and, from the same viewpoint, preferably 0.03 mol/100 g or less, more preferably 0.02 mol/100 g or less. More specifically, when the cleaning agent composition of the present invention is used, the content of component C relative to 100 g of the cleaning agent composition is preferably 0.005 mol/100 g or more and 0.03 mol/100 g or less, more preferably 0.01 mol/100 g or more and 0.02 mol/100 g or less.

From the viewpoint of improving the resin mask removal property, inhibiting copper corrosion and inhibiting copper discoloration, the molar ratio (B/C) (content of component B/content of component C) of component B to component C in the cleaning agent composition of the present invention is 1.5 or more, preferably 2 or more, more preferably 3 or more, and, from the same viewpoint, preferably 5 or less, more preferably 4 or less. More specifically, the molar ratio (B/C) is preferably 2 or more and 5 or less, more preferably 3 or more and 4 or less.

[Water (Component D)] The water (hereinafter also referred to as "Component D") contained in the detergent composition of the present invention may be, in one or more embodiments, ion exchange water, RO (reverse osmosis) water, distilled water, pure water, ultrapure water, etc.

The content of component D in the cleaning agent composition of the present invention can be regarded as the remaining part except component A, component B, component C and any of the following components. Specifically, from the viewpoint of improving the resin mask removal property, inhibiting copper corrosion, reducing the drainage treatment load, and reducing the impact on the substrate, the content of component D when using the cleaning agent composition of the present invention is preferably 45% by mass or more, more preferably 60% by mass or more, and further preferably 80% by mass or more, and from the viewpoint of improving the resin mask removal property, it is preferably 99% by mass or less, more preferably 98% by mass or less, and further preferably 97% by mass or less. More specifically, when the cleaning composition of the present invention is used, the content of component D is preferably 45 mass % to 99 mass %, more preferably 60 mass % to 98 mass %, and further preferably 80 mass % to 97 mass %.

From the viewpoint of improving the resin mask removal property and inhibiting copper corrosion, when using the cleaning agent composition of the present invention, the total amount of component A, component B, component C and component D is preferably 60 mass % or more, more preferably 90 mass % or more, and further preferably 95 mass % or more.

[Organic solvent (component E)] The cleaning agent composition of the present invention may further include an organic solvent (hereinafter also referred to as "component E") in one or more embodiments. Component E may be one kind or a combination of two or more kinds. As component E, in one or more embodiments, at least one solvent selected from glycol ethers and aromatic ketones may be exemplified. As glycol ethers, from the viewpoint of improving the removability of resin mask, inhibiting copper corrosion, and reducing the influence on the substrate, compounds having a structure in which 1 mol to 3 mol of ethylene glycol are added to an alcohol having 1 to 8 carbon atoms may be exemplified. As specific examples of glycol ethers, 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 can be cited. As aromatic ketones, from the perspective of improving the removability of resin mask, inhibiting copper corrosion, and reducing the impact on the substrate, acetophenone can be cited.

When the cleaning agent composition of the present invention contains component E, from the viewpoint of improving the resin mask removability, the content of component E when using the cleaning agent composition of the present invention is preferably 1 mass % or more, more preferably 2 mass % or more, and further preferably 3 mass % or more, and from the viewpoint of inhibiting copper corrosion, reducing the load of drainage treatment, and reducing the impact on the substrate, it is preferably 40 mass % or less, more preferably 20 mass % or less, and further preferably 6 mass % or less. More specifically, when using the cleaning agent composition of the present invention, the content of component E is preferably 1 mass % or more and 40 mass % or less, more preferably 2 mass % or more and 20 mass % or less, and further preferably 3 mass % or more and 6 mass % or less. When component E is a combination of two or more components, the content of component E refers to the total content thereof.

[Chelating agent (ingredient F)] The cleaning agent composition of the present invention may further contain a chelating agent (hereinafter also referred to as "ingredient F") in one or more embodiments. Component F may be one kind or a combination of two or more kinds. As component F, for example, a compound having two or more acid groups selected from carboxyl groups and phosphonic acid groups may be cited. From the viewpoint of improving the resin mask removal performance and inhibiting copper corrosion, a compound having four or less of the above acid groups is preferred. As specific examples of component F, in one or more embodiments, aminotrimethylenephosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, etidronic acid (1-hydroxyethane-1,1-diphosphonic acid, HEDP), etc. may be cited. Among them, from the perspective of reducing environmental burden, 2-phosphonobutane-1,2,4-tricarboxylic acid, etidronic acid (HEDP), etc., which are compounds that do not contain nitrogen atoms, are preferred.

From the viewpoint of improving the resin mask removal property and inhibiting copper corrosion, the molecular weight of component F is preferably 1000 or less, more preferably 500 or less.

When the cleaning agent composition of the present invention contains component F, from the viewpoint of improving the resin mask removal property and inhibiting copper corrosion, the content of component F when using the cleaning agent composition of the present invention is preferably 0.5 mass% or more, more preferably 1 mass% or more, and, from the same viewpoint, it is preferably 5 mass% or less, more preferably 3 mass% or less. More specifically, when using the cleaning agent composition of the present invention, the content of component F is preferably 0.5 mass% or more and 5 mass% or less, more preferably 1 mass% or more and 3 mass% or less. When component F is a combination of two or more, the content of component F refers to the total content thereof.

[Other ingredients] The detergent composition of the present invention may contain other ingredients as needed in addition to the above-mentioned ingredients A to F. Examples of other ingredients include ingredients that can be used in conventional detergents, such as organic solvents other than ingredient E, surfactants, chelating agents other than ingredient F, thickeners, dispersants, rust inhibitors, polymer compounds, cosolvents, antioxidants, preservatives, defoaming agents, antibacterial agents, etc. When the detergent composition of the present invention is used, the content of other ingredients is preferably 0% by mass to 2% by mass, more preferably 0% by mass to 1.5% by mass, further preferably 0% by mass to 1.3% by mass, further preferably 0% by mass to 1% by mass.

The cleaning composition of the present invention may not contain fluorine compounds in one or more embodiments.

From the viewpoint of reducing the load of drainage treatment and reducing the impact on the substrate, when using the cleaning agent composition of the present invention, the total content of organic matter derived from component A, component B, component C and any component (component E, component F, other components) is preferably 30 mass% or less, more preferably 25 mass% or less, further preferably 20 mass% or less, further preferably 16 mass% or less, and from the viewpoint of improving the removability of the resin mask, it is preferably 2 mass% or more, more preferably 3 mass% or more, further preferably 4 mass% or more, further preferably 6 mass% or more. More specifically, when the detergent composition of the present invention is used, the total content of organic matter derived from component A, component B, component C and any component (component E, component F, other components) is preferably 2 mass % to 30 mass %, more preferably 3 mass % to 25 mass %, further preferably 4 mass % to 20 mass %, further preferably 6 mass % to 16 mass %.

[Manufacturing method of cleaning agent composition] The cleaning agent composition of the present invention can be manufactured by mixing an alkali (component A), a supply source of ammonium ions (component B), thioglycolic acid (component C) or a salt thereof, water (component D), and any of the above components as required using a known method. For example, the cleaning agent composition of the present invention can be prepared by mixing an alkali (component A), a supply source of ammonium ions (component B), thioglycolic acid (component C) or a salt thereof, and water (component D) in one or more embodiments. Therefore, the present invention relates to a method for preparing a detergent composition, which includes the following steps: at least preparing an alkali (ingredient A), a supply source of ammonium ions (ingredient B), thioglycolic acid (ingredient C) or its salt, and water (ingredient D). In the present invention, "preparing" includes mixing an alkali (ingredient A), a supply source of ammonium ions (ingredient B), thioglycolic acid (ingredient C) or its salt, water, and any of the above-mentioned components as needed at the same time or in any order. In the method for preparing the detergent composition of the present invention, the preferred preparation amount of each component can be set to the same as the preferred content of each component of the detergent composition of the present invention.

The detergent composition of the present invention may be in a form that is used directly for cleaning, or may be prepared as a concentrate in which the amount of water (component D) is reduced within a range that does not impair storage stability by inducing separation or precipitation. From the viewpoint of transportation and storage, the concentrate of the detergent composition is preferably prepared as a concentrate with a dilution ratio of 3 times or more, and from the viewpoint of storage stability, it is preferably prepared as a concentrate with a dilution ratio of 30 times or less. The concentrate of the detergent composition can be used by diluting the components (component A, component B, component C, component D, component E, component F, and other components) with water (component D) in such a manner that the above-mentioned contents (i.e., the contents during cleaning) are obtained. Furthermore, the detergent composition concentrate can also be used by adding each component separately when it is used. In the present invention, "when used" or "when cleaning" of the detergent composition as a concentrated liquid refers to the state in which the detergent composition concentrate has been diluted.

[Object to be cleaned] In one or more embodiments, the cleaning agent composition of the present invention can be used to clean a substrate having a copper-containing metal layer and a resin mask on its surface. The copper-containing metal layer is a copper-plated layer in one or more embodiments. The copper-plated layer can be formed, for example, by an electroless copper plating method. In one or more other embodiments, the cleaning agent composition of the present invention can be used to clean an object to be cleaned to which a resin mask is attached. As the object to be cleaned, in one or more embodiments, an object to be cleaned having a copper-containing metal portion on its surface can be exemplified, for example, electronic components and intermediates in their manufacture. As an electronic component, for example, at least one component selected from metal plates such as printed circuit boards, wafers, copper plates and aluminum plates can be cited. The above-mentioned manufacturing intermediates are intermediate products in the manufacturing steps of electronic components, including intermediate products after resin mask treatment. As a specific example of the cleaned object with a resin mask attached, for example, electronic components with wiring or connection terminals formed on the surface of the substrate can be cited by welding or plating (copper plating, aluminum plating, nickel plating, etc.) using a resin mask. Therefore, the present invention relates to a use of the cleaning agent composition of the present invention in one embodiment, which is to use the cleaning agent composition of the present invention as a cleaning agent in the manufacture of electronic components. In addition, the cleaning agent composition of the present invention has excellent removal performance of resin masks in fine gaps in one or more embodiments. As the object to be cleaned, from the perspective of exerting the resin mask removal performance of the cleaning agent composition, a substrate having fine gaps and a resin mask in the gaps is preferred. As a substrate with fine gaps, there can be cited: a substrate having copper wiring (wire) and the minimum value of the spacing (gap) of the wiring is preferably 1 μm or more and preferably 10 μm or less, and more preferably 6 μm or less. In addition, the cleaning agent composition of the present invention can suppress damage to the substrate resin in one or more embodiments. As the object to be cleaned, from the perspective of exerting the low damage of the cleaning agent composition to the substrate resin, there can be cited a substrate having a resin on the surface, for example, preferably a substrate having a solder resist resin.

In terms of cleaning effect, the cleaning agent composition of the present invention can be suitably used in one or more embodiments to clean an object to which a resin mask is attached, or to which a resin mask has been subjected to coating and/or heat treatment. The resin mask can be, for example, a negative resin mask or a positive resin mask. In the present invention, the negative resin mask is formed using a negative resist, and for example, a negative resist layer subjected to exposure and/or development treatment can be cited. In the present invention, the positive resin mask is formed using a positive resist, and for example, a positive resist layer subjected to exposure and/or development treatment can be cited.

[Cleaning method] The cleaning method of the present invention includes, in one or more embodiments: using the cleaning agent composition of the present invention, a step of stripping a resin mask from a substrate (object to be cleaned) having a copper-containing metal layer and a resin mask on its surface (hereinafter also referred to as "stripping step"). The above-mentioned stripping step includes, in one or more embodiments, an operation of bringing the object to be cleaned into contact with the cleaning agent composition of the present invention. According to the cleaning method of the present invention, corrosion and discoloration of copper can be suppressed, and the resin mask can be stripped and removed efficiently. According to the cleaning method of the present invention, in one or more embodiments, the resin mask in the fine gap can be efficiently peeled off and removed. According to the cleaning method of the present invention, in one or more embodiments, damage to the substrate resin can be suppressed. As the substrate resin, for example, solder resist can be cited.

As a method of using the cleaning agent composition of the present invention to peel off the resin mask from the object to be cleaned, or a method of bringing the cleaning agent composition of the present invention into contact with the object to be cleaned, for example, there can be cited: a method of bringing the object into contact by immersing it in a cleaning bath containing the cleaning agent composition; a method of bringing the object into contact by spraying the cleaning agent composition (shower method); an ultrasonic cleaning method of irradiating the object with ultrasonic waves during immersion, etc. The cleaning agent composition of the present invention can be used directly for cleaning without dilution. As the object to be cleaned, there can be cited the above-mentioned objects to be cleaned.

The cleaning method of the present invention may include the following steps in one or more embodiments: after the object to be cleaned is brought into contact with the detergent composition, the object is washed with water and then dried. The cleaning method of the present invention may include the following steps in one or more embodiments: after the object to be cleaned is brought into contact with the detergent composition, the object is washed with water.

In order to easily exert the cleaning power of the cleaning agent composition of the present invention, the cleaning method of the present invention is preferably to irradiate the cleaning agent composition of the present invention with ultrasound when it is in contact with the object to be cleaned, and the ultrasound is more preferably of relatively high frequency. From the same point of view, the irradiation conditions of the above-mentioned ultrasound are preferably 26-72 kHz, 80-1500 W, and more preferably 36-72 kHz, 80-1500 W.

In the cleaning method of the present invention, the temperature of the cleaning composition is preferably 40° C. or higher, more preferably 50° C. or higher, in order to easily exert the cleaning power of the cleaning composition of the present invention, and is preferably 70° C. or lower, more preferably 60° C. or lower, in order to reduce the impact on the substrate.

[Method for manufacturing electronic components] The present invention, in one embodiment, relates to a method for manufacturing electronic components (hereinafter also referred to as "the method for manufacturing electronic components of the present invention"), which includes: using the cleaning method of the present invention, 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. The above-mentioned object to be cleaned can be cited as an example. The method for manufacturing electronic components of the present invention may include the following steps in one or more embodiments: after the above-mentioned cleaning step, etching the metal layer containing copper. Regarding the manufacturing method of electronic components of the present invention, by using the cleaning method of the present invention for cleaning, the corrosion and discoloration of copper can be suppressed, and the resin mask attached to the electronic components can be effectively removed, thereby realizing the manufacturing of electronic components with high reliability. Furthermore, by performing the cleaning method of the present invention, the resin mask attached to the electronic components can be easily removed, thereby shortening the cleaning time and improving the manufacturing efficiency of electronic components.

[Kit] The present invention, in one embodiment, relates to a kit (hereinafter also referred to as "the kit of the present invention"), which is used in any one of the cleaning method of the present invention and the method for manufacturing electronic parts of the present invention. The kit of the present invention is a kit for manufacturing the cleaning agent composition of the present invention in one or more embodiments. According to the kit of the present invention, a cleaning agent composition having excellent resin mask removal performance and capable of suppressing copper corrosion and discoloration can be obtained.

As an implementation method of the kit of the present invention, the following kit (three-liquid cleaning agent composition) can be cited: a solution containing component A (first liquid), a solution containing component B (second liquid), and a solution containing component C (third liquid) are included in a state of not mixing with each other, 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 when used. After mixing the first liquid, the second liquid, and the third liquid, they can also be diluted with water (component D) as needed. Each of the first liquid, the second liquid, and the third liquid can also contain any of the above components as needed. As another embodiment of the kit of the present invention, the following kit (two-liquid detergent composition) can be cited: a solution containing component A (first liquid) and a solution containing component B and component C (second liquid) are included in a non-mixed 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 when used. After mixing the first liquid and the second liquid, they can also be diluted with water (component D) as needed. The above-mentioned arbitrary components can also be included in each of the first liquid and the second liquid as needed. Example

Hereinafter, the present invention will be specifically described by way of embodiments, but the present invention is not limited to these embodiments.

1. Preparation of detergent compositions of Examples 1 to 9 and Comparative Examples 1 to 3 The components shown in Tables 1 to 2 were prepared in the amounts (mass %, active ingredient) listed in Tables 1 to 2, and the components were stirred and mixed to prepare detergent compositions of Examples 1 to 9 and Comparative Examples 1 to 3. The content of ammonium ion (component B) (mol/100 g, active ingredient), the content of thioglycolic acid (component C) (mass %, mol/100 g, active ingredient), and the molar ratio of ammonium ion/thioglycolic acid (B/C) in each prepared detergent composition are shown in Tables 1 to 2.

The following were used to prepare the cleaning agent compositions of Examples 1 to 9 and Comparative Examples 1 to 3. TMAH: Tetramethylammonium hydroxide [Showa Denko Co., Ltd., concentration 25%] (Component A) MEA: Monoethanolamine [Nippon Catalyst Co., Ltd.] (Component A) Ammonia [Fuji Film Wako Pure Chemical Co., Ltd., first grade, 25% aqueous solution] (Source of component B) Ammonium thioglycolate [Tokyo Chemical Industry Co., Ltd., 60% aqueous solution] (Source of components B and C) Water [Pure water below 1 μS/cm produced by the pure water device G-10DSTSET manufactured by ORGANO Co., Ltd.] (Component D) BDG: Diethylene glycol butyl ether [Nippon Emulsifier Co., Ltd., diethylene glycol monobutyl ether] (Component E) HEDP: Etidronic acid [Italmatch Japan Co., Ltd., Dequest2010, concentration 60%] (Component F) Ammonium formate [Fuji Film Wako Pure Chemical Industries, Ltd.] Dimethyl sulfoxide [Fuji Film Wako Pure Chemical Industries, Ltd.]

2. Evaluation of cleaning agent compositions (Examples 1 to 9 and Comparative Examples 1 to 2) The cleaning agent compositions prepared in Examples 1 to 9 and Comparative Examples 1 to 2 were evaluated as follows.

[Preparation of Sample 1] A photosensitive film layer for forming a PKG (package) substrate circuit was pressed onto the surface of the electroless-plated substrate under the following conditions, and an exposure treatment was performed to harden it (exposure step), thereby obtaining a substrate (sample 1, 30 mm × 50 mm) having a resin mask (hardened anti-corrosion layer). (1) Lamination: Lamination was performed using a clean roller (RY-505Z manufactured by RAYON Industrial Co., Ltd.) and a vacuum applicator (VA7024/HP5 manufactured by Rohm and Haas Company) at a roller temperature of 50°C and a roller pressure of 1.4 Bar. (2) Exposure: Exposure was performed using a direct writing device for printed substrates (Mercurex LI-9500, manufactured by SCREEN Graphic and Precision Solutions Co., Ltd.) at an exposure dose of 15 mJ/ ^cm2 .

[Cleaning test] Add 100 g of each cleaning agent composition of Examples 1 to 9 and Comparative Examples 1 to 2 to a tall 200 mL glass beaker, heat to 50°C, and stir at 600 rpm using a rotor (fluororesin (PTFE), φ8 mm×25 mm). In this state, immerse sample 1 for 10 minutes. Then, immerse and rinse in a rinse tank with 100 g of water added to a 100 mL glass beaker, and then dry with a nitrogen blower.

[Resin mask peeling time (evaluation of peeling property (removability))] In the above cleaning test, the time (minutes) until the resin mask is completely removed under visual observation is measured.

[Evaluation of Cu etching rate (Evaluation of copper corrosion)] 2.5 L of each cleaning agent composition was adjusted, heated to 50°C, circulated by a box-type spray cleaner equipped with a dense 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 ⁾ on sample 2 (substrate with a copper-plated layer on the surface) with a copper-plated surface (area, 25 cm2 per single side and 50 ^cm2 for both sides). After diluting the cleaning agent composition, the amount of copper dissolved was measured by ICP (Inductively Coupled Plasma) analysis (Agilent 5110 ICP-OES manufactured by Agilent Technologies). The density of copper was taken as 8.94 g/cm ³ by the following formula, and the Cu etching rate (μm/min) was evaluated based on the dissolved amount. It can be judged that the lower the value of the Cu etching rate, the better the copper corrosion inhibition effect. Cu etching rate (μm/min) = copper dissolved amount (weight) ÷ copper density ÷ coating area ÷ treatment time

[Appearance of copper on substrate (evaluation of copper discoloration)] In the above-mentioned evaluation of etching rate, the copper part was visually observed to see if it had discolored.

[Evaluation of damage to substrate resin] The above cleaning test was performed on the substrate with solder resist resin (sample 3), and the resin part of the substrate was visually confirmed to see if there was any change in color before and after the above cleaning test, and the evaluation was performed according to the following evaluation criteria. <Evaluation criteria> A: No change was observed before and after the cleaning test. B: Visible change was observed before and after the cleaning test.

[Table 1] Table 1 Embodiment Comparison Example 1 2 3 4 5 6 7 8 9 1 2 Composition TMAH (ingredient A) Quality% 1.00 7.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 MEA (component A) Quality% 0.05 ammonia Quality% 0.60 0.60 0.60 0.30 0.90 0.60 0.60 0.60 0.60 0.60 Ammonium thioglycolate Quality% 1.80 1.80 1.80 1.80 1.80 1.00 2.60 1.80 1.80 1.80 Water (ingredient D) Quality% 96.60 90.60 93.60 93.90 93.30 94.40 92.80 88.75 53.60 94.20 95.40 BDG (ingredient E) Quality% 3.00 40.00 HEDP (ingredient F) Quality% 1.80 Total(mass%) 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 Detergent composition Thioglycolic acid (ingredient C) content Quality% 1.52 1.52 1.52 1.52 1.52 0.84 2.19 1.52 1.52 1.52 0.00 Thioglycolic acid (ingredient C) content mol/100 g 0.02 0.02 0.02 0.02 0.02 0.01 0.02 0.02 0.02 0.02 0.00 Content of Ammonium Ions (Component B) mol/100 g 0.05 0.05 0.05 0.03 0.07 0.04 0.06 0.05 0.05 0.02 0.04 Ammonium ion/thioglycolic acid (mol ratio B/C) 3.14 3.14 3.14 2.07 4.21 4.85 2.48 3.14 3.14 1.00 Reviews Removability: Resin mask peeling time (minutes) 12 12 11 13 10 11 11 11 11 >20 11 Corrosion: Cu etching rate (µm/min) 0.02 0.02 0.02 0.01 0.05 0.05 0.01 0.02 0.01 0.00 0.15 Appearance of copper on substrate No discoloration No discoloration No discoloration Slightly discolored No discoloration No discoloration Slightly discolored No discoloration No discoloration Discoloration No discoloration Low damage to substrate resin A A A A A A A A B A A

As shown in Table 1, it can be seen that compared with Comparative Example 1 in which the molar ratio B/C is not within the specified range and Comparative Example 2 that does not contain component C, the cleaning agent compositions of Examples 1 to 9 can inhibit copper corrosion and discoloration, and have excellent resin mask removal properties. In addition, regarding the cleaning agent composition of Example 3, the following results were obtained (data not shown): When thioglycerol was used instead of ammonium thioglycolate, the resin mask removal property and copper discoloration inhibition effect were worse than those of Example 3.

3. Evaluation of detergent compositions (Example 8 and Comparative Example 3) The detergent compositions prepared in Example 8 and Comparative Example 3 were used to conduct the following evaluations.

[Preparation of Sample 4 with Thick Film DF] A photosensitive thick film (thickness of 140 μm) for forming a PKG substrate circuit was laminated onto the surface of the substrate after electroless plating under the following conditions, and an exposure treatment was performed to harden it (exposure step), thereby obtaining a substrate (Sample 4, 30 mm×50 mm) with a resin mask (hardened anti-corrosion layer). (1) Lamination: Lamination was performed using a Clean Roller (RY-505Z manufactured by RAYON Industrial Co., Ltd.) and a vacuum applicator (VA7024/HP5 manufactured by Rohm and Haas Company) at a roller temperature of 50°C and a roller pressure of 1.4 Bar. (2) Exposure: Exposure was performed using a direct writing device for printed substrates (Mercurex LI-9500, manufactured by SCREEN Graphic and Precision Solutions Co., Ltd.) at an exposure dose of 15 mJ/ ^cm2 .

[Preparation of Sample 5 with Fine Line Circuit Pattern] A photosensitive film layer for forming a PKG substrate circuit was pressed onto the surface of the substrate after electroless plating under the following conditions. After exposure treatment to harden it (exposure step), electrolytic plating was performed to obtain a substrate with a line/space of 5 μm/5 μm (hardened anti-corrosion layer) and a fine line circuit pattern (Sample 5, 30 mm×50 mm). (1) Lamination: Lamination was performed using a Clean Roller (RY-505Z manufactured by RAYON Industrial Co., Ltd.) and a vacuum applicator (VA7024/HP5 manufactured by Rohm and Haas Company) at a roller temperature of 50°C and a roller pressure of 1.4 Bar. (2) Exposure: Exposure was performed using a direct writing device for printed substrates (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 cleaning agent composition of Example 8 and Comparative Example 3 was added to a tall 200 mL glass beaker, heated to 50°C, and stirred at 600 rpm using a rotor (fluororesin (PTFE), φ8 mm×25 mm). Sample 4 or 5 was immersed in this state for 10 minutes. Then, it was immersed in a rinse tank in which 100 g of water was added to a 100 mL glass beaker and rinsed, and then dried by a nitrogen blower.

[Resin mask peeling time (evaluation of removability)] In the above cleaning test of sample 4, the time (minutes) until the resin mask is completely removed under visual observation is measured.

[Removability of fine-line circuit patterns (evaluation of removability)] Using an optical microscope "Digital Microscope VHX-2000" (manufactured by KEYENCE Co., Ltd.), magnified to 1000 times, visually checked whether there was any residual resin mask in the fine-line circuit pattern of sample 5 after the above cleaning test.

[Table 2] Table 2 Embodiment Comparison Example 8 3 Composition TMAH (ingredient A) Quality% 4.00 1.00 MEA (component A) Quality% 0.05 5.00 ammonia Quality% 0.60 Ammonium thioglycolate Quality% 1.80 Water (ingredient D) Quality% 88.75 77.00 BDG (ingredient E) Quality% 3.00 12.00 HEDP (ingredient F) Quality% 1.80 Ammonium formate Quality% 1.00 Dimethyl sulfoxide Quality% 4.00 Total(mass%) 100.00 100.00 Detergent composition Thioglycolic acid (ingredient C) content Quality% 1.52 0.00 Thioglycolic acid (ingredient C) content mol/100 g 0.02 0.00 Content of Ammonium Ions (Component B) mol/100 g 0.05 0.02 Ammonium ion/thioglycolic acid (mol ratio B/C) 3.14 Reviews Removability: Stripping time of thick film DF (minutes) 11 >20 Removability: Stripping of fine-line circuit patterns No residue There are residues

As shown in Table 2, it can be seen that the cleaning agent composition of Example 8 has excellent resin mask removal performance compared with Comparative Example 3 which does not contain component C. [Industrial Applicability]

According to the present invention, a cleaning method can be provided which has excellent resin mask removal performance and can inhibit copper corrosion and discoloration. The cleaning method of the present invention can shorten the cleaning steps of electronic parts with resin masks attached and improve the performance and reliability of the manufactured electronic parts, thereby improving the productivity of semiconductor devices.

Claims (13)

A substrate cleaning method includes the step of using a cleaning agent composition to strip a resin mask from a substrate having a copper-containing metal layer and a resin mask on its surface. The cleaning agent composition contains an alkali (component A), ammonium ions (NH ₄ ⁺ , component B), thioglycolic acid (component C) and water (component D), and the molar ratio of component B to component C (B/C) is greater than 1.5. In the cleaning method of claim 1, the copper-containing metal layer is a copper-plated layer. A cleaning method as claimed in claim 1, wherein the resin mask is a hardened anti-corrosion layer. A cleaning method as claimed in claim 1, wherein the content of component D when using the above-mentioned cleaning agent composition is 60% by mass or more. A cleaning method as claimed in claim 1, wherein component A is tetraalkylammonium hydroxide. A cleaning method as claimed in claim 1, wherein the substrate has copper wiring, and the minimum spacing between the wiring is greater than 1μm and less than 10μm. A cleaning method as claimed in any one of claims 1 to 6, wherein the substrate is a substrate having a solder resist resin. A method for manufacturing electronic components, comprising the step of using a cleaning method as described in any one of claims 1 to 7 to clean a substrate having a copper-containing metal layer and a resin mask on its surface. A cleaning agent composition for stripping resin masks contains tetraalkylammonium hydroxide (component A), ammonium ions (NH ₄ ⁺ , component B), thioglycolic acid (component C) and water (component D), and the molar ratio of component B to component C (B/C) is greater than 1.5. For example, in the detergent composition of claim 9, the content of component A is greater than 0.5 mass % and less than 10 mass %, and the content of component C is greater than 0.4 mass % and less than 4 mass %. For example, in the cleaning agent composition of claim 9, the total amount of component A, component B, component C and component D is 90% by mass or more. A cleaning agent composition as claimed in any one of claims 9 to 11, wherein the content of component D is 60% by mass or more. A use of a cleaning agent composition is to use the cleaning agent composition to clean a substrate having a copper-containing metal layer and a resin mask on the surface. The cleaning agent composition contains an alkali (component A), ammonium ions (NH ₄ ⁺ , component B), thioglycolic acid (component C) and water (component D), and the molar ratio of component B to component C (B/C) is greater than 1.5.