TWI754753B - Detergent composition for lead-free solder flux, cleaning method of lead-free solder flux - Google Patents

Abstract

The main purpose of the present invention is to provide a cleaning composition for lead-free solder flux, It can clean the flux residue generated when soldering with rosin flux or water-soluble flux in a short period of time, and further, even if the object to be cleaned is a complex and microstructured mounting board, etc., it still remains. Has excellent clearance cleanability.

(n係1~3之整數，R係表示碳數1~4之烷基或羥烷基)。 The present invention provides a cleaning agent composition for lead-free solder flux, which is characterized by comprising: (A) a composition selected from the group consisting of diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether and dipropylene glycol dimethyl ether At least one organic solvent in the group of base ethers; (B) an alcohol amine represented by the following formula (1); and (C) a hydroxycarboxylic acid;

(n is an integer of 1 to 3, and R is an alkyl group or a hydroxyalkyl group having 1 to 4 carbon atoms).

Description

Detergent composition for lead-free solder flux, cleaning method of lead-free solder flux

The present invention relates to a cleaning composition for lead-free solder flux and a cleaning method for lead-free solder flux.

Soldering is generally performed when surface mounting electronic components on a printed circuit board. Usually, during soldering, the oxide film on the surface of the solder and the base metal is removed, or a flux is used to prevent the reoxidation of the surface of the solder and the base metal and obtain sufficient solderability. However, flux is corrosive and flux residues can degrade the quality of printed circuit boards. Therefore, in some cases, it is necessary to wash and remove the flux residue.

Traditionally, rosin-based flux (rosin flux) is widely used for solder bonding of surface mount components, and the residue of this rosin flux is cleaned with halogenated hydrocarbons such as fluorochlorofluorocarbons. However, because halogenated hydrocarbons are extremely harmful to the environment, their use has been restricted. Therefore, various substitutes such as halogenated hydrocarbons have been reviewed as cleaning agents for rosin flux residues. For example, a detergent containing a polyoxyalkylene alkyl ether-based non-halogen-based organic solvent or the like has been proposed, for example, where the risk of fire and the impact on the environment are small, and the rosin flux residue is excellent in the dissolving power (Patent Document 1). ~3).

In addition, as a countermeasure against environmental problems, water is used to replace halogenated hydrocarbons for cleaning was also reviewed. Fluxes that can be washed with water are not hydrophobic, such as rosin-based fluxes, but water-soluble fluxes such as polyether-based resins with added activators and solvents. Since the residue of water-soluble flux is hygroscopic, it must be cleaned. This is different from the rosin flux residue that does not have to be cleaned. Therefore, the residue of water-soluble flux is usually washed with water, but there are cases where the washing is insufficient.

Here, it is considered to use the cleaning agents of the above-mentioned Patent Documents 1 to 3 as cleaning agents for water-soluble flux residues. However, these cleaning agents are not reviewed for the purpose of removing water-soluble flux residues, and water-soluble flux residues have characteristics different from those of rosin flux residues. Detergents are still difficult to adequately clean water-soluble flux residues. Moreover, although the detergent composition of patent document 3 contains the alcohol amine which has an alkyl group, such an amine has the problem of corroding metal substrates, such as a copper plate.

【Prior technical literature】 【Patent Literature】

[Patent Document 1] Japanese Patent Application Laid-Open No. 4-57899

[Patent Document 2] Japanese Patent Application Laid-Open No. 8-73893

[Patent Document 3] International Publication No. 2009/020199

The main object of the present invention is to provide a cleaning agent set for lead-free solder flux The finished product can clean the flux residue generated when soldering with rosin flux or water-soluble flux in a short period of time, and further, even if the object to be cleaned is a mounting substrate with a complex and fine structure, etc. , it still has excellent clearance cleaning.

The inventors of the present invention, as a result of intensive research, have found that the aforementioned problems can be solved when the detergent composition contains an organic solvent containing a specific glycol ether, an amine, and a divalent carboxylic acid, and the present invention has been completed. That is, this invention relates to the following cleaning composition for lead-free solder fluxes, and the cleaning method of a lead-free solder flux.

1. A cleaning agent composition for a lead-free solder flux, characterized by comprising: (A) containing a composition selected from the group consisting of diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether and dipropylene glycol dimethyl ether At least one organic solvent in the group; (B) an alcohol amine represented by the following formula (1); and (C) a hydroxycarboxylic acid;

(n is an integer of 1 to 3, and R is an alkyl group or a hydroxyalkyl group having 1 to 4 carbon atoms).

2. The cleaning composition for a lead-free solder flux according to the preceding item 1, wherein the component (B) is N,N-bis(2-hydroxyethyl)-N-cyclohexylamine.

3. The cleaning composition for lead-free solder flux according to the preceding item 1 or 2, wherein the component (C) is at least 1 selected from the group consisting of citric acid, isocitric acid, tartaric acid and malic acid kind.

4. The cleaning composition for a lead-free solder flux according to any one of the preceding paragraphs 1 to 3, which contains 2.8 to 70% by weight of component (A), 0.04 to 5% by weight of component (B), and 0.01% by weight of component (B) Component (C) of ~2 wt %, and water of 5 to 97 wt %.

5. The cleaning composition for lead-free solder flux according to any one of the preceding items 1 to 4, wherein the surface tension at a temperature of 25°C is 10 to 60 dyne/cm.

6. A cleaning method for a lead-free solder flux, characterized in that the cleaning composition for the lead-free solder flux of any one of the preceding paragraphs 1 to 5 is washed in contact with a to-be-cleaned object to which the lead-free solder flux is adhered. net.

The cleaning agent composition for lead-free solder flux of the present invention (hereinafter referred to as the cleaning agent composition) can clean the flux generated when soldering with rosin flux or water-soluble flux in a short time. In addition, even if the object to be cleaned is a mounting substrate with a complex and fine structure, etc., it has excellent clearance cleaning performance. Furthermore, the aforementioned cleaning composition has the effect of not corroding the metal substrate.

[Fig. 1] When there is "no flux residue" in the clearance cleanability, it is "◎"

[Fig. 2] When there is "flux residue" in the clearance cleanability, it is a diagram of "X"

The "lead-free solder flux" that is the object of cleaning of the detergent composition of the present invention specifically refers to the tin-containing flux residue derived from lead-free solder, for example: (A) Powdered lead-free The flux residue formed after soldering the paste formed by the solder and the flux composition, or (b) the electrode formed by the lead-free solder, the flux residue produced by the soldering through the flux composition.

The "lead-free solder" includes, for example, Sn-Ag-based solder, Sn-Cu-based solder, Sn-Ag-Cu-based solder, Sn-Zn-based solder, Sn-Sb-based solder, and the like.

In addition, the "flux composition" specifically includes resin acids (natural rosin, superposed rosin, α, β unsaturated carboxylic acid-modified rosin, etc.) or synthetic resins (acrylic resin, polyamide resin, etc.), for example. etc.) base resins; active agents (organic acids such as adipic acid, halogen-based compounds such as diethylamine hydrobromide, etc.); thixotropic agents (hardened castor oil, ethylene diamide hydroxystearate) etc.); solvent (diethylene glycol monohexyl ether, diethylene glycol monobutyl ether, etc.) as the main component of the composition.

The detergent composition of the present invention contains: (A) at least one selected from the group consisting of diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether and dipropylene glycol dimethyl ether (hereinafter, abbreviated as (A) component); (B) an alcohol amine represented by the following formula (1) (hereinafter, abbreviated as (B) component); and (C) hydroxycarboxylic acid (hereinafter, abbreviated as (C) component).

【Change 3】

(n is an integer of 1 to 3, and R is an alkyl or hydroxyalkyl group with 1 to 4 carbon atoms)

(A) Component contains at least 1 sort(s) chosen from the group which consists of diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether, and dipropylene glycol dimethyl ether. Since these dialkyldialkylene glycols have low surface tension and viscosity, they tend to easily enter the gaps of the substrates.

In addition, the component (A) may be used together with other glycol ethers as long as the clearance cleaning property is not impaired. Other glycol ethers are not particularly limited, and examples thereof include diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether, and diethylene glycol mono-n-propylene. base ether, diethylene glycol di-n-propyl ether, diethylene glycol methyl propyl ether, diethylene glycol ethyl propyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol diethylene glycol n-butyl ether, diethylene glycol methyl butyl ether, diethylene glycol ethyl butyl ether, diethylene glycol propyl butyl ether, diethylene glycol mono-n-pentyl ether, diethylene glycol Alcohol di-n-amyl ether, diethylene glycol methyl amyl ether, diethylene glycol ethyl amyl ether, diethylene glycol propyl amyl ether, diethylene glycol butyl amyl ether, diethyl ether Diethylene glycol ethers such as glycol mono-n-hexyl ether; dipropylene glycol monomethyl ether, corresponding to these three or tetraethylene glycol ethers, etc., these can be used alone or in combination of two or more When used, its content is not particularly limited, but when the detergent composition of the present invention is 100% by weight, it is preferably 40% by weight or less.

The content of component (A) is not particularly limited, but from the viewpoint of interstitial cleaning properties, when the detergent composition of the present invention is 100% by weight, it is usually 2.8 to 70% by weight, preferably 5 to 70% by weight. % by weight, more preferably 20 to 70% by weight.

The component (B) is an alcohol amine represented by the following formula (1), which does not contain a metal The substrate corrodes and is an essential component for the cleaning performance of the flux.

(n is an integer of 1 to 3, and R is an alkyl or hydroxyalkyl group with 1 to 4 carbon atoms)

Examples of the alcoholamine represented by the above formula (1) include N-hydroxyethyl-N-methyl-N-cyclohexylamine, N-ethyl-N-(2-hydroxyethyl)-N-ring Hexylamine, N,N-bis(2-hydroxymethyl)-N-cyclohexylamine, N,N-bis(2-hydroxyethyl)-N-cyclohexylamine, etc. These can be used individually or in combination of 2 or more types. Among these, N,N-bis(2-hydroxyethyl)-N-cyclohexylamine is preferable from the viewpoint of clearance cleanability.

The content of the component (B) is not particularly limited, but from the viewpoint of interstitial cleaning properties, when the detergent composition of the present invention is 100% by weight, it is usually 0.04 to 5% by weight, preferably 0.04 to 3% by weight. % by weight, more preferably 0.1 to 2% by weight.

In the detergent composition of the present invention, alcohol amine (B-1) (hereinafter, abbreviated as (B-1) component) or aliphatic amine (B2) (hereinafter, abbreviated as “component”) other than (B) component may be added. (B-2) component) etc. are used together. The component (B-1) is not particularly limited, and examples thereof include diethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, Nn-butyldiethanolamine, Nt-butyldiethanolamine, triethanolamine, N-(β-aminoethyl)ethanolamine, N-(β-aminoethyl)isopropanolamine, etc. Further, the component (B-2) is not particularly limited, and examples thereof include octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, 2-ethylhexylamine, and the like. The first-class aliphatic amine; N,N,N',N'-tetramethylpentamethylenediamine, N,N,N',N'-tetraethylpentamethylenediamine, N,N,N',N'- Tetraisopropylpentamethylenediamine, N,N,N',N'-tetra-n-propylpentamethylenediamine, N,N,N',N'-tetramethylhexamethylene diamine, N,N,N',N'-tetraethylhexamethylenediamine, N,N,N',N'-tetraisopropylhexamethylenediamine, N,N,N ', N'-tetra-n-propyl hexamethylene diamine and other tertiary diamines; bis(2-dimethylaminoethyl) ether, bis(2-diethylaminoethyl) ether , bis(2-diisopropylamine ethyl) ether, bis(2-di-n-propylamine ethyl) ether, etc. diamine alkyl ethers; 1,1,7,7-tetramethyl diamine Ethylenetriamine, 1,1,7,7-tetraethyldiethylenetriamine, 1,1,7,7-tetraisopropyldiethylenetriamine, 1,1,7,7-tetra-n-propane Diethylenetriamine Triamines such as methyl-1,1,7,7-tetraisopropyldiethylenetriamine, 4-methyl-1,1,7,7-tetra-n-propyldiethylenetriamine, etc. These can be used individually or in combination of 2 or more types. The content of the components (B-1) and (B-2) is not particularly limited, but from the viewpoint of not corroding the metal substrate, when the detergent composition of the present invention is 100% by weight, it is 2% by weight or less. good.

(C) component is not specifically limited, Various well-known thing can be used, For example, citric acid, isocitric acid, malic acid, tartaric acid, etc. are mentioned. In addition, salts of the aforementioned acids can also be used, and examples of the salts include sodium salts, potassium salts, ammonium salts, and alkanolamine salts. These can be used individually or in combination of 2 or more types. Among them, at least one selected from the group consisting of citric acid, isocitric acid, and malic acid is preferred, and citric acid is more preferred, from the viewpoint of flux residue cleaning properties.

The content of the component (C) is not particularly limited, but from the viewpoint of the solubility of the flux residue, when the detergent composition of the present invention is 100% by weight, it is usually 0.01 to 2% by weight, preferably 0.1 to 2% by weight. 2% by weight, more preferably 0.1 to 1% by weight.

The detergent composition of the present invention further contains water. Examples of water include pure water, ion-exchanged water, purified water, and the like. In addition, mixing of water may be performed once or divided into plural times. The content of water is also not particularly limited, but from the viewpoint of non-hazardous materialization of the detergent, when the detergent composition of the present invention is 100% by weight, it is usually 5 to 97% by weight, preferably 20 to 90% by weight , more preferably 20 to 50% by weight.

In addition, the detergent composition of the present invention may contain a non-halogen organic solvent as necessary, for example, containing 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2 - Solvents for nitrogen atoms of imidazolidinone, 1,3-dipropyl-2-imidazolidinone, N-methyl-2-pyrrolidone, etc.; hydrocarbons such as hexane, heptane, octane, etc.; methanol, ethanol , alcohols such as benzyl alcohol; ketones such as acetone, methyl ethyl ketone, etc.; ethers such as diethyl ether, tetrahydrofuran, glycol ether, etc.; esters such as ethyl acetate and methyl acetate, etc. etc. can be used alone or in combination of two or more.

Moreover, as long as the detergent composition of the present invention does not impair the intended effect of the present invention, various conventional additives such as nonionic surfactants (except those corresponding to component (A)) may be added. , Anionic surfactants, cationic surfactants and other surfactants.

Examples of nonionic surfactants include: general formula (2): R ² -O-(CH ₂ -CH ₂ -O)eH (in the formula, R ² is an alkyl group having 8 to 20 carbon atoms, and e is an alkyl group having 8 to 20 carbon atoms. Represents an integer from 0 to 20.) The compounds represented, or the ethylene oxide adducts of fatty acid amides, sorbitan fatty acid esters, sucrose fatty acid esters, and fatty acid alkanolamides correspond to these polyamides. Oxypropane-based surfactants and the like can be used alone or in combination of two or more.

Examples of anionic surfactants include sulfate-based anionic surfactants (sulfuric acid ester salts of higher alcohols, alkyl sulfate ester salts, polyoxyethylene alkyl sulfate ester salts) etc.); sulfonate-based anionic surfactants (alkylsulfonates, alkylbenzenesulfonates, etc.), etc., these can be used alone or in combination of two or more.

The cationic surfactants include, for example, alkylated ammonium salts, quaternary ammonium, and the like, and these can be used alone or in combination of two or more.

The amphoteric surfactants include, for example, amino acid type, inner salt type amphoteric surfactants, and the like, and these may be used alone or in combination of two or more.

The detergent composition of the present invention may contain various conventional additives. The additives are not particularly limited, and examples thereof include chelating agents, antioxidants, redox agents, scale inhibitors, rust inhibitors, pH adjusters, antifoaming agents, and the like.

The physical properties of the detergent composition of the present invention are not particularly limited. For example, at a temperature of 25°C, the surface tension is usually about 10-60 dyne/cm, preferably about 10-50 dyne/cm, more preferably about 10 ~40dyne/cm. By making the surface tension within this range, the clearance cleanability can be easily improved.

In addition, the detergent composition of the present invention has no ignition point and is not a dangerous substance.

Moreover, the detergent composition of this invention may contain the non-halogen type organic solvent other than this (A) component as needed. For example, nitrogen-containing compound solvents (1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, 1,3-dipropyl-2-imidazoline ketones, N-methyl-2-pyrrolidone, etc.); hydrocarbon-based solvents (hexane, heptane, octane, etc.); alcohol-based solvents (methanol, ethanol, benzyl alcohol, etc.); ketone-based solvents (acetone, methyl alcohol, etc.) ethyl ketone, etc.); ether-based solvents (diethyl ether, tetrahydrofuran, glycol ethers, etc.); ester-based solvents (ethyl acetate, methyl acetate, etc.), etc., these can be used alone or in two or more used in combination.

<How to remove lead-free solder flux>

The method for removing the lead-free solder flux of the present invention can remove the flux by contacting the cleaning composition of the present invention with the object to be cleaned to which the lead-free solder flux is attached.

」，荒川化學工業股份有限公司製，日本專利第2621800號等)之方法等。 The usage of the detergent composition of the present invention is not particularly limited, and various conventional methods can be employed. For example, a method of spraying the cleaning agent composition on the object to be cleaned to which the lead-free solder flux is adhered using a spray device (refer to Japanese Patent Application Laid-Open No. 2007-096127), in the cleaning agent composition. The method of immersing the object to be cleaned in the middle and ultrasonic cleaning, using a straight-through cleaning device (registered trademark ""

”, the method of Arakawa Chemical Industry Co., Ltd., Japanese Patent No. 2621800, etc.).

After removing the lead-free solder flux using the cleaning composition of the present invention, the cleaning product obtained by washing with water is preferred. In particular, the removal method of the present invention is preferably a method of spraying water on the cleaning material after spraying the cleaning agent composition of the present invention on the lead-free solder flux to obtain the cleaning material.

In addition, the washing process may be repeated several times. For example, the cleaning agent composition adhering to the surface of the cleaning object can be effectively removed by performing the finishing cleaning treatment after the pre-rinsing treatment for the above-mentioned cleaning object.

The pre-rinsing treatment can be performed according to a conventional pre-rinsing treatment method using pure water or the like.

To complete the rinsing process, just follow the conventional method. For example, the method of using pure water etc. with respect to a pre-rinsing process object is mentioned.

After the pre-rinsing treatment and/or the completion of the rinsing treatment, a drying treatment may be performed as necessary.

In addition, in the washing step, water is sprayed on the state of the object to be washed by spraying. In the following process, from the viewpoint of low foamability, it is preferable that the detergent composition of the present invention also does not contain the aforementioned various surfactants.

【Example】

Hereinafter, the present invention will be described in detail by way of Examples and Comparative Examples, but the scope of the present invention should not be limited thereby.

(Preparation of cleaning composition for lead-free solder flux)

Each component shown in Table 1 was mixed (weight % basis), and the cleaning composition for lead-free solder fluxes of Examples 1-10 and Comparative Examples 1-6 was prepared.

[Corrosion of metal substrate (confirm the presence or absence of discoloration)]

in a 200ml beaker. 150 g of the cleaning agent composition for lead-free solder flux of Example 1 was taken, put into an aluminum plate (aluminum plate A1050P (prescribed by JIS H3100), size: 70 mm×150 mm×0.8 mm), and immersed at 60° C. for 10 minutes. After cooling, the aluminum plate was taken out, and after repeated careful water washing, droplets were removed by nitrogen blowing. Check the discoloration of the aluminum plate with the naked eye. In addition, the cleaning compositions for lead-free solder fluxes of Examples 2 to 10 and Comparative Examples 1 to 6 were also evaluated in the same manner. The results are shown in Table 1 (the same applies hereinafter).

(assessment benchmark)

○: No discoloration of aluminum plate ×: Discoloration of aluminum plate

[Production of water-soluble flux residue]

30 parts by weight of commercially available water-soluble flux (product name "WF-6317", manufactured by Senju Metal Industry Co., Ltd.) and lead-free solder powder (96.5Sn3.0Ag0.5Cu, 20-38μm, Mitsui Metal Mining Co., Ltd. Company made) 70 parts by weight were mixed to prepare a solder paste. Put the aforementioned solder paste into the soft The paste pot is heated and melted on a hot plate with a temperature of 270°C, then cooled, and the water-soluble flux residue separated from the solder paste is collected. The aforementioned flux residue was used as a model for the residue after soldering with lead-free water-soluble solder.

A part of the above-mentioned flux residue was collected, and the tin concentration was measured using a wavelength-dispersive X-ray fluorescence analyzer (product name "ZSX100e", Rigaku Co., Ltd.). As a result, 5% by weight of tin was detected.

[Manufacture of a model substrate for cleaning]

By forming a plurality of resist bumps with a height of 30 μm on the epoxy glass substrate (length 40cm×width 40cm×thickness 1mm) of the base, and then a glass plate (length 16cm× 16cm in width x 0.5mm in thickness) to form a substrate for cleaning the gap. Then, the above-mentioned water-soluble flux residue was diluted with methanol into 10 μl of a liquid having a concentration of 15%, and was supplied to the concave portion between the glass small plates to prepare a model substrate for cleaning.

[Gap cleaning performance]

The above-mentioned model substrate was spray-cleaned (pressure 0.2 MPa, temperature 50°C, 1 minute) with the cleaning composition for lead-free solder flux of Example 1 (liquid temperature 50°C). The substrate was cleaned by spray cleaning with water (pressure: 0.2 MPa, 1 minute), and the droplets were removed by nitrogen blowing, followed by drying with a circulating air dryer at 80° C. for 10 minutes. The flux residue remaining on the board after drying was observed using an optical microscope (VHX6000 manufactured by KEYENCE Corporation). The evaluation benchmarks are as follows. In addition, the cleaning compositions for lead-free solder fluxes of Examples 2 to 10 and Comparative Examples 1 to 6 were also evaluated in the same manner.

(assessment benchmark)

◎: No flux residue (see Figure 1)

○: There is a small amount of flux residue, but it is within the range that does not affect the electrical reliability of the substrate

△: There is a small amount of flux residue, which is within the range that will affect the electrical reliability of the substrate

×: Flux residue is present (see Fig. 2)

※The content of each component is expressed as a weight ratio (wt%).

The abbreviations in Table 1 represent the following compounds.

． DEDG: Diethylene glycol diethyl ether

． MEDG: Diethylene glycol ethyl methyl ether

． DPDM: Dipropylene glycol dimethyl ether

． BDG: Diethylene glycol mono-n-butyl ether

． CHE-20: N,N-bis(2-hydroxyethyl)-N-cyclohexylamine (trade name: "Amino alcohol CHE-20", manufactured by Nippon Emulsifier Co., Ltd.)

． MBD: N-n-butyldiethanolamine

[Gap cleanability for model substrates supplied with rosin flux residues]

A solder paste containing a commercially available rosin-based flux (product name "Pine Solder VAPY-LF219", manufactured by Arakawa Chemical Industry Co., Ltd.) was used, and the same procedure as described in paragraphs [0055] to [0057] was used. Method to make a model substrate (since this product is a solder paste, the adjustment process of the solder paste is omitted). When the above-mentioned model substrate was cleaned with the cleaning composition for lead-free solder flux of Example 4, it was clearly shown that it had the same excellent clearance cleaning performance.

Claims (6)

A cleaning agent composition for lead-free solder flux, which is characterized by comprising: (A) containing a composition selected from the group consisting of diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether and dipropylene glycol dimethyl ether At least one organic solvent in the group; (B) an alcohol amine represented by the following formula (1); (C) a hydroxycarboxylic acid; and water; Component (B) of ~5 wt %, component (C) of 0.01 to 2 wt %, and water of 5 to 97 wt %;

(n is an integer of 1 to 3, and R is an alkyl group or a hydroxyalkyl group having 1 to 4 carbon atoms). The cleaning composition for lead-free solder flux as claimed in claim 1, wherein the component (B) is N,N-bis(2-hydroxyethyl)-N-cyclohexylamine. The detergent composition for lead-free solder flux according to claim 1 or 2, wherein the component (C) is at least one selected from the group consisting of citric acid, isocitric acid, tartaric acid and malic acid. The cleaning agent composition for lead-free solder flux as claimed in claim 1 or 2 of the patented scope, wherein the surface tension at a temperature of 25°C is 10-60 dyne/cm. For example, the cleaning agent composition for lead-free solder flux according to claim 3, wherein the surface tension at a temperature of 25°C is 10-60 dyne/cm. A cleaning method for lead-free solder flux, which is characterized in that the cleaning composition for lead-free solder flux according to any one of items 1 to 5 of the scope of application is brought into contact with the object to be cleaned that adheres to the lead-free solder flux And wash.

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