JP7006826B1 - Detergent composition for lead-free solder flux, cleaning method for lead-free solder flux - Google Patents

Abstract

PROBLEM TO BE SOLVED: To clean a flux residue generated during soldering in a short time, and further to have excellent gap cleaning property even when the object to be cleaned is a mounted substrate having a complicated and fine structure, and after rinsing treatment. Provided is a cleaning agent composition for a lead-free solder flux that does not cause stains derived from the cleaning agent. A monoalkyl ether (A1) represented by a specific general formula, a dialkyl ether (A2) represented by a specific general formula, an alkyl monoalkanolamine (B), and a hydroxycarboxylic acid (C) are included. A lead-free cleaning agent composition for solder flux, wherein the total content of the component (A1) and the content of the component (A2) is 60 to 98% by weight in 100% by weight of the cleaning agent composition. Detergent composition for solder flux. [Selection diagram] None

Description

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

When surface mounting electronic components on a printed wiring board, soldering is generally performed. Usually, at the time of soldering, a flux is used for the purpose of removing the oxide film on the surface of the solder and the base material, or preventing the reoxidation of the surface of the solder and the base material, and obtaining sufficient solderability. However, the flux is corrosive and the flux residue degrades the quality of the printed wiring board. Therefore, the flux residue may be removed by washing.

Conventionally, a rosin-based flux (rosin flux) has been widely used for solder bonding of surface mount components, and the residue of this rosin flux has been washed with a halogen-based hydrocarbon such as chlorofluorocarbon. However, since the use of halogen-based hydrocarbons is restricted because they are extremely harmful to the environment, various alternative cleaning agents for rosin flux residues have been studied. For example, detergents mainly containing a glycol ether solvent have been proposed as having a small risk of ignition, an impact on the environment, and an excellent dissolving power of a rosin flux residue (Patent Documents 1 to 3).

However, the cleaning agents of Patent Documents 1 and 2 are used when the object to be cleaned is a mounted circuit board having a complicated and fine structure such as a printed wiring board of a type in which chips are joined to a circuit with a large number of fine solder bumps. Detergency (gap detergency) was insufficient. Further, the cleaning agent of Patent Document 3 contains dialkanolamine, and stains derived from the cleaning agent are generated on the substrate after the rinsing treatment.

Japanese Unexamined Patent Publication No. 4-0578999 Japanese Unexamined Patent Publication No. 8-073893 International Publication No. 2009/020199

The present invention can clean the flux residue generated during soldering in a short time, and also has excellent gap cleaning property even when the object to be cleaned is a mounted substrate having a complicated and fine structure, and is rinsed. It is an object of the present invention to provide a cleaning agent composition for a lead-free solder flux which does not cause stains derived from the cleaning agent later.

The present inventor has diligently studied the combination of glycol ether and amine in the cleaning agent composition, and found that the above-mentioned problems can be solved, and completed the present invention. That is, the present invention relates to the following detergent composition for lead-free solder flux and a method for cleaning lead-free solder flux.

（式（１）において、Ｒ^１は炭素数１～６のアルキル基、Ｘは水素原子又はメチル基、ａは１～３の整数を表す。）

（式（２）において、Ｒ^２、Ｒ^３は独立して炭素数１～４のアルキル基、Ｙは水素原子又はメチル基、ｂは１～３の整数を表す。） 1. 1. Lead-free solder containing monoalkyl ether (A1) represented by the general formula (1), dialkyl ether (A2) represented by the general formula (2), alkyl monoalkanolamine (B) and hydroxycarboxylic acid (C). A detergent composition for flux,
Detergent composition for lead-free solder flux in which the total content of the component (A1) and the content of the component (A2) is 60 to 98% by weight in 100% by weight of the cleaning agent composition.

(In the formula (1), R ¹ represents an alkyl group having 1 to 6 carbon atoms, X represents a hydrogen atom or a methyl group, and a represents an integer of 1 to 3).

(In the formula (2), R ² and R ³ independently represent an alkyl group having 1 to 4 carbon atoms, Y represents a hydrogen atom or a methyl group, and b represents an integer of 1 to 3).

2. 2. The weight ratio of each component is (A1) component 5 to 90% by weight, (A2) component 5 to 90% by weight, (B) component 0.5 to 15% by weight, and (C) component 0.1 to 5% by weight. The cleaning agent composition for lead-free solder flux according to the above item 1.

3. 3. Item 2. The above item 1 or 2, wherein the component (B) contains at least one selected from the group consisting of N-methylethanolamine, N-ethylethanolamine, Nn-butylethanolamine and N, N-dibutylethanolamine. Detergent composition for lead-free solder flux.

4. The detergent composition for lead-free solder flux according to any one of the above items 1 to 3, wherein the component (C) is at least one selected from the group consisting of citric acid, isocitric acid, tartaric acid and malic acid.

5. The lead-free solder flux cleaning agent composition according to any one of the above items 1 to 4, further comprising water (D).

6. A method for cleaning a lead-free solder flux, wherein the cleaning agent composition for a lead-free solder flux according to any one of the above items 1 to 5 is brought into contact with an object to be cleaned to which the lead-free solder flux is attached.

According to the lead-free solder flux cleaning agent composition of the present invention (hereinafter, also referred to as a cleaning agent composition), the flux residue generated during soldering can be cleaned in a short time, and the object to be cleaned is complicated and fine. Even when the mounting substrate has a structure or the like, it has excellent gap cleaning properties, and stains derived from the cleaning agent do not occur after the rinsing treatment.

The "lead-free solder flux" to be cleaned of the cleaning agent composition of the present invention specifically means a flux residue containing a metal (for example, tin, etc.) derived from lead-free solder, and for example, ( A) Flux residue generated after soldering with a paste consisting of powdery lead-free solder and flux composition (for example, reflow soldering), and (b) an electrode formed with lead-free solder, the flux composition. Examples thereof include flux residues generated after soldering through soldering (for example, reflow soldering).

Examples of the "lead-free solder" include Sn—Ag-based solder, Sn—Cu-based solder, Sn-Ag-Cu-based solder, Sn—Zn-based solder, Sn—Sb-based solder, and the like.

The "flux composition" includes, for example, base resins such as resin acids (natural rosin, polymerized rosin, α, β unsaturated carboxylic acid-modified rosin, etc.) and synthetic resins (acrylic resin, polyamide resin, etc.), and activity. Agents (organic acids such as adipic acid, halogen compounds such as diethylamine hydrogen bromide), thixotropic agents (hardened castor oil, hydroxystearic acid ethylenebisamide, etc.), solvents (diethylene glycol monohexyl ether, diethylene glycol monobutyl ether, etc.) Examples thereof include a composition containing the main component.

Hereinafter, the detergency and the crevice detergency are simply described, but both of them mean those for the flux residue.

The detergent composition of the present invention has a monoalkyl ether (A1) represented by the general formula (1) (hereinafter referred to as a component (A1)) and a dialkyl ether (A2) represented by the general formula (2). Hereinafter, it contains (A2) component), alkylmonoalkanolamine (B) (hereinafter referred to as (B) component) and hydroxycarboxylic acid (C) (hereinafter referred to as (C) component).

The component (A1) is a compound represented by the following general formula (1), and is a component that imparts excellent detergency to the detergent composition.

(In the formula (1), R ¹ represents an alkyl group having 1 to 6 carbon atoms, X represents a hydrogen atom or a methyl group, and a represents an integer of 1 to 3).

Among the components (A1), those with a = 1 include, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n-propyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono n-butyl ether, and ethylene. Glycol monoisobutyl ether, ethylene glycol mono s-butyl ether, ethylene glycol mono t-butyl ether, ethylene glycol mono n-pentyl ether, ethylene glycol mono n-hexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono n -Propyl ether, propylene glycol monoisopropyl ether, propylene glycol mono n-butyl ether, propylene glycol monoisobutyl ether, propylene glycol mono s-butyl ether, propylene glycol mono t-butyl ether, propylene glycol mono n-pentyl ether, propylene glycol mono n- Hexyl ether and the like can be mentioned.

Among the components (A1), those having a = 2 include, for example, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono n-propyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono n-butyl ether, diethylene glycol monoisobutyl ether, and diethylene glycol. Mono s-butyl ether, diethylene glycol mono t-butyl ether, diethylene glycol mono n-pentyl ether, diethylene glycol mono n-hexyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono n-propyl ether, dipropylene glycol Monoisopropyl ether, Dipropylene glycol mono-n-butyl ether, Dipropylene glycol monoisobutyl ether, Dipropylene glycol monos-butyl ether, Dipropylene glycol monot-butyl ether, Dipropylene glycol mono n-pentyl ether, Dipropylene glycol mono n- Hexyl ether and the like can be mentioned.

Among the components (A1), those with a = 3 include, for example, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol mono n-propyl ether, triethylene glycol monoisopropyl ether, and triethylene glycol mono. n-butyl ether, triethylene glycol monoisobutyl ether, triethylene glycol monos-butyl ether, triethylene glycol monot-butyl ether, triethylene glycol mono n-pentyl ether, triethylene glycol mono n-hexyl ether, tripropylene glycol monomethyl ether , Tripropylene glycol monoethyl ether, Tripropylene glycol mono-n-propyl ether, Tripropylene glycol monoisopropyl ether, Tripropylene glycol mono-n-butyl ether, Tripropylene glycol monoisobutyl ether, Tripropylene glycol monos-butyl ether, Tripropylene glycol Examples thereof include mono t-butyl ether, tripropylene glycol mono n-pentyl ether, and tripropylene glycol mono n-hexyl ether.

These (A1) components may be used alone or in combination of two or more. Among them, in the general formula (1), an alkyl group having R ¹ having 3 or 4 carbon atoms is preferable, and propylene glycol mono-n-propyl ether and diethylene glycol mono-n- are preferable because the cleaning agent composition exhibits excellent detergency. Butyl ether and triethylene glycol mono-n-butyl ether are more preferable.

The content of the component (A1) is preferably 5 to 90% by weight, preferably 20 to 80% by weight, with the detergent composition of the present invention as 100% by weight, from the viewpoint that the detergent composition exhibits excellent gap cleaning properties. % Is more preferable, and 30 to 70% by weight is even more preferable.

The component (A2) is a compound represented by the following general formula (2), and is a component that imparts excellent gap cleaning properties to the detergent composition.

(In the formula (2), R ² and R ³ independently represent an alkyl group having 1 to 4 carbon atoms, Y represents a hydrogen atom or a methyl group, and b represents an integer of 1 to 3).

Among the components (A2), those having b = 1 include, for example, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol ethyl methyl ether, ethylene glycol din-propyl ether, ethylene glycol diisopropyl ether, and ethylene glycol din-. Examples thereof include butyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol ethyl methyl ether, propylene glycol di n-propyl ether, propylene glycol diisopropyl ether, and propylene glycol di n-butyl ether.

Among the components (A2), those having b = 2 include, for example, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol din-propyl ether, diethylene glycol diisopropyl ether, diethylene glycol din-butyl ether, and dipropylene glycol dimethyl ether. , Dipropylene glycol diethyl ether, dipropylene glycol ethyl methyl ether, dipropylene glycol din-propyl ether, dipropylene glycol diisopropyl ether, dipropylene glycol din-butyl ether and the like.

Among the components (A2), those having b = 3 include, for example, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol ethyl methyl ether, triethylene glycol din-propyl ether, triethylene glycol diisopropyl ether, and the like. Triethylene glycol din-butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, tripropylene glycol ethylmethyl ether, tripropylene glycol din-propyl ether, tripropylene glycol diisopropyl ether, tripropylene glycol din-butyl ether, etc. Can be mentioned.

These (A2) components may be used alone or in combination of two or more. Among them, those having an alkyl group having b = ² and R2 and R3 independently having 1 or ² carbon atoms in the general formula (2) from the viewpoint that the cleaning agent composition exhibits excellent gap cleaning property. Is preferable, and diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, and dipropylene glycol dimethyl ether are more preferable.

The content of the component (A2) is preferably 5 to 90% by weight, preferably 10 to 70% by weight, with the detergent composition of the present invention as 100% by weight, from the viewpoint that the detergent composition exhibits excellent gap cleaning properties. % Is more preferable, and 15 to 60% by weight is even more preferable.

In the present invention, the total of the content of the component (A1) and the content of the component (A2) is 60 to 98% by weight in 100% by weight of the detergent composition. Within this range, the detergent composition has excellent detergency and gap detergency. From the same point of view, the total content of the component (A1) and the component (A2) is preferably 70 to 98% by weight, more preferably 75 to 98% by weight.

Since the detergent composition of the present invention tends to be excellent in detergency and gap detergency, it is preferable that the content of the component (A1) is higher than the content of the component (A2). The content ratio of the component (A1) and the component (A2) is preferably 1 <(A1) / (A2) ≦ 15 and 1.1 ≦ (A1) / (A2) ≦ 5 in terms of weight ratio. More preferred.

The component (B) is an alkyl monoalkanolamine, and refers to a compound having one alkanol group (a hydroxy group bonded to an alkane skeleton) and one or two alkyl groups. By containing the component (B), the detergent composition exhibits excellent detergency, and discoloration of the substrate that occurs during reflow can be removed. Further, after the rinsing treatment, stains caused by the detergent composition will not occur.

Examples of the component (B) include N-methylmethanolamine, N-ethylmethanolamine, Nn-propylmethanolamine, Nn-butylmethanolamine, N-methylethanolamine, N-ethylethanolamine, and N. -N-propylethanolamine, N-isopropylethanolamine, Nn-butylethanolamine, N-methylpropanolamine, N-ethylpropanolamine, Nn-propylpropanolamine, N-isopropylpropanolamine, Nn -N-monoalkyl monoalkanol amines such as butylpropanolamine, N-methylbutanolamine, N-ethylbutanolamine, Nn-propylbutanolamine, N-isopropylbutanolamine, Nn-butylbutanolamine; N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-din-propylethanolamine, N, N-din-butylethanolamine, N, N-dimethylpropanolamine, N, N-dimethylisopropanol Examples thereof include dialkyl monoalkanol amines such as amines and N, N-dimethylbutanol amines. These may be used alone or in combination of two or more. Of these, N-methylethanolamine, N-ethylethanolamine, Nn-butylethanolamine, and N, N-dibutylethanolamine are preferable from the viewpoint of suppressing the generation of stains caused by the cleaning agent composition.

The content of the component (B) is preferably 0.5 to 15% by weight, preferably 1 to 15% by weight, with the detergent composition of the present invention as 100% by weight, from the viewpoint that the detergent composition exhibits excellent gap cleaning properties. 10% by weight is more preferable, and 1 to 5% by weight is further preferable.

The component (C) is a hydroxycarboxylic acid, which is a component that imparts excellent detergency to the detergent composition and removes discoloration of the substrate that occurs during reflow. Examples of the component (C) include citric acid, isocitric acid, tartaric acid, malic acid and the like. Further, the salt of the acid may be used, and examples of the salt include sodium salt, potassium salt, ammonium salt, alkanolamine salt and the like. These may be used alone or in combination of two or more. Among these, at least one selected from the group consisting of citric acid, isocitric acid, tartaric acid and malic acid is preferable, and citric acid is more preferable, from the viewpoint of removing discoloration of the substrate that occurs during reflow.

The content of the component (C) is 0.1 to 5% by weight, assuming that the cleaning agent composition of the present invention is 100% by weight, because the discoloration of the substrate that occurs during reflow can be removed while cleaning the flux residue. Preferably, 0.3 to 3% by weight is more preferable, and 0.3 to 2% by weight is further preferable.

The detergent composition of the present invention also contains water (D). Examples of water include pure water, ion-exchanged water, purified water and the like. Further, the mixing of water may be divided into one time or a plurality of times. The water content is preferably 0.5 to 30% by weight, preferably 2 to 25% by weight, with the detergent composition of the present invention as 100% by weight, from the viewpoint of dissolving the component (C) in the detergent composition. % Is more preferable, and 5 to 20% by weight is even more preferable.

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

The detergent composition of the present invention may contain a surfactant such as a nonionic surfactant, an anionic surfactant, or a cationic surfactant to the extent that the intended effect of the present invention is not impaired. good.

Examples of the nonionic surfactant include general formula (3): ^R4 -O- ( _CH2 - _CH2 -O) _e -H (in the formula, ^R4 is an alkyl group having 8 to 20 carbon atoms. e represents an integer of 0 to 20), ethylene oxide adducts of fatty acid amides, sorbitan fatty acid esters, sucrose fatty acid esters, fatty acid alkanolamides, and their corresponding polyoxypropylene-based surfactants. Etc., and these may be used alone or in combination of two or more.

Examples of the anionic surfactant include sulfate ester-based anionic surfactants (sulfate ester salts of higher alcohols, alkyl sulfate ester salts, polyoxyethylene alkyl sulfate ester salts, etc.) and sulfonate-based anionic surfactants. (Alkyl sulfonate, alkyl benzene sulfonate, etc.) and the like can be mentioned, and these may be used alone or in combination of two or more.

Examples of the cationic surfactant include alkylated ammonium salts and quaternary ammonium salts, which may be used alone or in combination of two or more.

Examples of the amphoteric tenside include an amino acid type amphoteric tenside and a betaine type amphoteric tenside agent, which may be used alone or in combination of two or more.

Various known additives may be added to the detergent composition of the present invention. The additive is not particularly limited, and examples thereof include a chelating agent, an antioxidant, an oxidation reducing agent, a scale inhibitor, a rust inhibitor, a pH adjuster, and an antifoaming agent. These may be used alone or in combination of two or more.

As the physical properties of the detergent composition of the present invention, for example, the pH is preferably 7 to 12.

Moreover, it is preferable that the detergent composition of the present invention does not have a flash point.

<How to clean lead-free solder flux>
The method for cleaning the lead-free solder flux of the present invention can remove the flux by bringing the cleaning agent composition of the present invention into contact with an object to be cleaned to which the lead-free solder flux is attached.

Various known methods can be adopted as the method of using the detergent composition of the present invention. For example, a method of spraying the cleaning agent composition onto the object to be cleaned to which lead-free solder flux is attached using a spray device (see JP-A-2007-09612), and immersing the cleaning agent in the cleaning agent composition. A method of ultrasonic cleaning, a method of using a direct cleaning device (registered trademark "Direct Pass", manufactured by Arakawa Chemical Industry Co., Ltd., Patent No. 2621800, etc.) and the like can be mentioned.

After cleaning the lead-free solder flux with the cleaning agent composition of the present invention, it is preferable to rinse the obtained cleaning product with water. In particular, as the cleaning method of the present invention, a method of spraying the cleaning agent composition of the present invention onto a lead-free solder flux to obtain a cleaning product and then spraying water onto the cleaning product is preferable.

Further, the rinsing treatment may be repeated a plurality of times. For example, by performing a pre-rinsing treatment on the object to be cleaned and then a finishing rinsing treatment, the detergent composition adhering to the surface of the cleaning object can be effectively removed.

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

The finish rinsing treatment can be performed according to a conventionally known method, and examples thereof include a method of treating a pre-rinsing product with pure water or the like.

If necessary, a drying treatment may be performed after the pre-rinsing treatment and / or after the finishing rinsing treatment.

When the rinsing treatment is performed by spraying water onto the object to be cleaned, the detergent composition of the present invention does not contain the above-mentioned various surfactants from the viewpoint of low foaming property. Is preferable.

Hereinafter, the present invention will be described with reference to examples, but the scope of the present invention is not limited thereto. In addition, "%" in Examples and Comparative Examples is based on weight unless otherwise specified.

<Preparation of detergent composition for lead-free solder flux>
Each component shown in Table 1 or Table 2 was mixed (based on weight%) to prepare detergent compositions for lead-free solder flux of Examples 1 to 16 and Comparative Examples 1 to 8.

<Manufacturing of test copper plate>
Flux (product name: "PHA-214", manufactured by Arakawa Chemical Industry Co., Ltd.) 0.03 g on a copper plate of phosphor deoxidized copper (copper plate C1220P, specified in JIS H3100) with a length of 40 mm, a width of 40 mm, and a thickness of 0.3 mm. (Specified in JIS Z-3282, product name: "FLF01-W1.6", manufactured by Matsuo Handa Co., Ltd.), 0.2 g of lead-free wire solder, reflowed at 250 ° C for 30 seconds, and tested. A copper plate for soldering was produced.

100 g of the lead-free solder flux cleaning agent composition of Example 1 was taken in a 100 ml beaker, a test copper plate was immersed in the beaker, and the mixture was stirred at 70 ° C. for 5 minutes (this treatment is referred to as “cleaning treatment”). The test copper plate was taken out, immersed in 100 g of pure water, stirred for another 5 minutes, rinsed with pure water, and droplets were removed by a nitrogen blow (this treatment is called "rinsing treatment"). Further, the same procedure was used for the lead-free solder flux cleaning agent compositions of Examples 2 to 16 and Comparative Examples 1 to 8.

<Cleanability>
The flux residue remaining on the test copper plate after cleaning was observed with an optical microscope (device name: "VHX6000", manufactured by KEYENCE CORPORATION), and the removal rate was determined from the following formula A. The evaluation criteria are shown below. The results are shown in Tables 1 and 2 (the same applies hereinafter).
(Formula A) Removal rate (%) = [{(Adhesion area before flux cleaning)-(Adhesion area after flux cleaning)} / (Adhesion area before flux cleaning)] × 100

(Evaluation criteria)
◎: Removal rate is 85% or more ○: Removal rate is 75% or more and less than 85% △: Removal rate is 65% or more and less than 75% ×: Removal rate is less than 65%

<Removal of discoloration of copper plate>
Regarding the test copper plate after the cleaning treatment, it was visually confirmed whether the discoloration of the copper plate caused by the reflow could be removed.
〇: The discoloration of the copper plate that occurred after reflow could be removed.
X: The discoloration of the copper plate that occurred after reflow could not be removed.

<Stains derived from the detergent composition>
It was confirmed whether or not stains derived from the detergent composition were generated on the test copper plate after the rinsing treatment. The test copper plate used in the cleaning agent compositions of Comparative Examples 3 and 8 could not be confirmed because the removal of discoloration was insufficient.
◯: No stains derived from the detergent composition were generated.
X: Spots derived from the detergent composition occurred.

<Preparation of flux solution>
20g of flux (product name: "PHA-214", manufactured by Arakawa Chemical Industry Co., Ltd.) and lead-free wire solder (specified in JIS Z-3282, product name: "FLF01-W1.6", Matsuo Handa Co., Ltd.) (Manufactured) 80 g was placed in an ointment can, heated and melted on a hot plate at a temperature of 250 ° C., cooled, and a flux residue was collected. The flux residue was added to a mixture of 20 g of ethanol and 80 g of chloroform to a concentration of 5% and dissolved to prepare a flux solution.

<Preparation of test board>
Several resist bumps with a height of 30 μm are formed on the base glass epoxy substrate (length 40 cm x width 40 cm x thickness 1 mm), and a glass small plate (length 16 cm x width 16 cm x thickness 0.5 mm) that serves as a spacer is formed. It was glued from the top of the sheet. Then, 10 μL of the flux solution was supplied to the recesses between the glass plates to prepare a test substrate.

<Gap cleaning property>
The test substrate was spray-cleaned (pressure 0.2 MPa, temperature 70 ° C., 3 minutes) with the lead-free solder flux cleaning agent composition (liquid temperature 70 ° C.) of Example 1. The test substrate was rinsed by spray washing with water (pressure 0.2 MPa, 3 minutes), droplets were removed by nitrogen blow, and then dried in a circulation dryer at 80 ° C. for 10 minutes. The flux residue remaining on the test substrate after drying was observed with an optical microscope (device name: "VHX6000", manufactured by KEYENCE CORPORATION), and the removal rate was determined from the following formula A. The evaluation criteria are shown below. The evaluation criteria are shown below. The same applies to the detergent compositions for flux of Examples 2 to 16 and Comparative Examples 1 to 8.

(Formula A) Removal rate (%) = [{(Adhesion area before flux cleaning)-(Adhesion area after flux cleaning)} / (Adhesion area before flux cleaning)] × 100

(Evaluation criteria)
◎: Removal rate is 85% or more ○: Removal rate is 75% or more and less than 85% △: Removal rate is 65% or more and less than 75% ×: Removal rate is less than 65%

※各成分の含有量は、重量割合（重量％）で表される。

* The content of each component is expressed as a weight ratio (% by weight).

※各成分の含有量は、重量割合（重量％）で表される。

* The content of each component is expressed as a weight ratio (% by weight).

The abbreviations in Tables 1 and 2 indicate the following compounds.
(A1) component ・ BDG: diethylene glycol mono n-butyl ether ・ BTG: triethylene glycol mono n-butyl ether ・ PFG: propylene glycol monopropyl ether (A2) component ・ DEDG: diethylene glycol diethyl ether ・ MEDG: diethylene glycol ethylmethyl ether ・ DMFDG: Dipropylene glycol dimethyl ether (B) component-MBM: N-n-butylethanolamine, trade name: "Aminoalcohol MBM", manufactured by Nippon Embroidery Co., Ltd.-MEM: N-ethylethanolamine, trade name: "Aminoalcohol MEM" 2B: N, N-dibutylaminoethanol (= N, N-dibutylethanolamine), trade name: "Amino Alcohol 2B", MBD: Mono n- Butyldiethanolamine, trade name: "Amino Alcohol MBD", manufactured by Nippon Emulsorium Co., Ltd.

Claims (6)

Lead-free solder containing monoalkyl ether (A1) represented by the general formula (1), dialkyl ether (A2) represented by the general formula (2), alkyl monoalkanolamine (B) and hydroxycarboxylic acid (C). A detergent composition for flux,
In 100% by weight of the detergent composition, the total of the content of the component (A1) and the content of the component (A2) is 60 to 98% by weight .
A detergent composition for a lead-free solder flux in which the content ratio of the component (A1) and the component (A2) is 1.1 ≦ (A1) / (A2) ≦ 5 .

(In the formula (1), R ¹ represents an alkyl group having 1 to 4 carbon atoms, X represents a hydrogen atom or a methyl group, and a represents an integer of 1 to 3).

(In the formula (2), R ² and R ³ independently represent an alkyl group having 1 or 2 carbon atoms, Y represents a hydrogen atom or a methyl group, and b represents an integer of 1 to 3). The weight ratio of each component is (A1) component 5 to 90% by weight, (A2) component 5 to 90% by weight, (B) component 0.5 to 15% by weight, and (C) component 0.1 to 5% by weight. The cleaning agent composition for lead-free solder flux according to claim 1. Claim 1 in which the component (B) comprises at least one selected from the group consisting of N-methylethanolamine, N-ethylethanolamine, Nn-butylethanolamine and N, N-din-butylethanolamine. Or the cleaning agent composition for lead-free solder flux according to 2. The detergent composition for lead-free solder flux according to any one of claims 1 to 3, wherein the component (C) is at least one selected from the group consisting of citric acid, isocitric acid, tartaric acid and malic acid. The detergent composition for a lead-free solder flux according to any one of claims 1 to 4, further comprising water (D). A method for cleaning a lead-free solder flux, wherein the cleaning agent composition for a lead-free solder flux according to any one of claims 1 to 5 is brought into contact with an object to be cleaned to which the lead-free solder flux is attached.