JP2002173700A - Flux cleaner composition and method for cleaning flux - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flux cleaner composition excellent in performances as the flux cleaner and environment-friendly. SOLUTION: This flux cleaner composition contains α-hydroxyisobutyric acid and an α-hydroxyisobutyric acid ester, but does not contain any chlorine- based component, nor any fluorine-based component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning composition for cleaning flux after soldering. It also relates to a method for cleaning flux.

[0002]

2. Description of the Related Art Flux removal after soldering has conventionally been carried out with trichloroethane. Trichloroethane not only dissolves rosin (rosin), which is the main component of the flux, but also has low toxicity and low flash point. Therefore, it was indispensable as a flux detergent excellent in safety. However, the use of trichlorethane, which is a chlorinated solvent, is restricted due to environmental problems.
After that, flux cleaning after soldering became difficult. Therefore, there is an urgent need to develop a trichloroethane alternative detergent. In addition, the rosin-based flux is heated for a long time during soldering, so that acidic components of rosin (usually the main component of rosin-based flux is abietic acid) react with the solder metal to form a chemical reaction such as salt. The residue was observed without dissolving in the trichloroethane-based detergent. Therefore, it is necessary that the trichloroethane-substitute cleaning solvent not only dissolves rosin before heating, but also dissolves flux components that have been heat-altered.

The following publications disclose cleaning compositions in which various solvents are combined. For example, a flux detergent comprising 1,2-dimethyl 2,4-diphenylpentane (Japanese Patent Application Laid-Open No. 8-109397), a detergent composition comprising a glycol ether compound, propylene glycol alkyl ether acetate and water ( JP 1
No. 0-204497), a detergent composition containing a hydrocarbon solvent, a polyoxyalkylene dialkyl ether and an amine compound (JP-A-10-168488, JP-A-10-81893, JP-A-10-114899).
), A detergent composition comprising dipropylene glycol monopropyl ether, octanoic acid and diethanolamine (JP-A-11-286698), an organic compound capable of coordinating a hydrocarbon solvent with a metal ion, a detergent composition comprising n-hexane and 1-n-octyl-2-pyrrolidinone (JP-A-8-231989);
Flux removing detergent comprising water-soluble amide compound or water-soluble lactone compound, alkanolamine or quaternary lower alkylammonium hydroxide and water (JP-A-9-59683), flux comprising quaternary ammonium salt and hydrazine aqueous solution Detergent (JP-A-7-
No. 166196), a detergent composition containing a monoterpene phenol as a main component (Japanese Unexamined Patent Publication No. 7-97095),
And isopropyl bromide as a flux detergent (Japanese Patent Application Laid-Open No. 7-292393). As described above, flux cleaning agents have been used in combination with many organic solvents, mineral acids and organic acids, surfactants, water, and the like, but these have insufficient cleaning properties against flux and have advantages and disadvantages.

[0004]

As described above, in the technical field of the art, non-halogen solvents are the main components, and there are no problems in toxicity and safety to the human body. Development of a cleaning agent which has no accumulation of flux and has a high dissolving power for fluxes after soldering has become an important issue.

[0005]

The present inventors have conducted intensive studies to develop a flux detergent composition having the above-mentioned preferable performance, and as a result, have found that α-hydroxyisobutyric acid and α-hydroxyisobutyrate ester have been obtained. The inventors have found that a flux solvent composition containing as an essential component has excellent cleaning ability, and arrived at the present invention. That is, the present invention relates to a flux detergent composition comprising α-hydroxyisobutyric acid and α-hydroxyisobutyric acid ester and containing no chlorine and fluorine-based components.

The flux detergent composition of the present invention comprises α-
It contains 0.1 to 30% by weight, preferably 0.5 to 20% by weight of hydroxyisobutyric acid and 10 to 99.9% by weight of α-hydroxyisobutyrate. Methyl α-hydroxyisobutyrate as the α-hydroxyisobutyrate,
Examples thereof include ethyl α-hydroxyisobutyrate and isopropyl α-hydroxyisobutyrate.

In the present invention, α-hydroxyisobutyric acid and α
In addition to the hydroxyisobutyrate, another organic solvent may be further added. As the other organic solvent, an organic solvent containing no chlorine and fluorine is used. Specifically, hexane, heptane, octane, nonane, decane, dodecane, aliphatic hydrocarbons such as undecane, benzene, toluene, xylene, ethylbenzene, cumene, mesitylene, naphthalene, aromatic hydrocarbons such as tetralin, naphthalene, Alcohols such as methanol, ethanol, propanol, butanol, pentanol, hexanol and heptanol; phenols such as phenol, cresol and xylenol; ketones such as acetone, methyl ethyl ketone, pentanone, hexanone, cyclohexanone, methyl isobutyl ketone, diisobutyl ketone and acetophenone , Ethers such as dipropyl ether, dibutyl ether, dihexyl ether, anisole, phenetole, dioxane, tetrahydrofuran,
Ethyl formate, methyl acetate, ethyl acetate, benzyl acetate,
Benzoate, citrate, succinate, cinnamate, abietate, stearate, oxalate, malonate, maleate, tartrate, sebacate, phthalate, lactate , Esters such as glycolic acid esters, nitrogen compounds such as acetonitrile and amines, sulfur compounds such as dimethyl sulfoxide, 2-methoxyethanol, 2-ethoxyethanol, diethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol Dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol Dimethyl ether, it can be exemplified compound and diethylene glycol diethyl ether, but is not limited thereto. The addition amount of these solvents is in the range of 0 to 70% by weight.

[0008] The flux detergent composition of the present invention contains 0 to
Water may be contained within the range of 20% by weight.
A surfactant or an antioxidant may be added to these flux detergent compositions to improve the detergency. Further, a coloring agent may be added to clarify the type of the flux detergent composition. Alternatively, various additives can be used in combination for other purposes.

The solution viscosity of the flux detergent composition of the present invention is preferably 0.3 to 5.0 mPa · s. 5.0mPa ・
s, the solvent separation between the substrate and the cleaning agent is poor, and 0.3
If it is lower than mPa · s, the cleaning effect will not be improved. The surface tension of the flux detergent composition of the present invention is preferably 35 dyn / cm or less. More preferably, it is 30 dyn / cm or less, and 35 dy
If it is larger than n / cm, the cleaning effect is inferior.

The washing temperature may be room temperature, or may be increased by heating if necessary. Washing method is not particularly limited, dipping method, shower method, spray method, paddle method,
A bubble method, an ultrasonic cleaning method, or the like is preferably used.

The washing liquid of the present invention contains α-hydroxyisobutyric acid and α-hydroxyisobutyric acid ester, and can also wash thermally modified rosin. However, it is not preferable that α-hydroxyisobutyric acid, which is an acidic component, remains on the circuit board after washing. After washing with the flux detergent composition of the present invention, α-hydroxyisobutyric acid can be easily removed by rinsing with a solution that can be easily mixed with the washing solution and does not contain an acidic component, thereby suppressing metal corrosion. I also found that I can do it. That is, the components are soldered on a circuit board using a flux, and the flux remaining on the board is replaced with a flux detergent composition containing α-hydroxyisobutyric acid and α-hydroxyisobutyrate and containing no chlorine and fluorine components. After washing with an object, rinse with a liquid that can be easily mixed with the flux detergent composition and does not contain acidic components. As the rinsing liquid used here, α-hydroxyisobutyric acid ester, the above-mentioned other organic solvents, a mixed solvent thereof and the like are used. Water may be used as long as it can be mixed with the cleaning liquid. If necessary, a surfactant or the like may be added to the rinsing liquid. The rinsing method is the dipping method, the shower method,
A spray method, a paddle method, a bubble method, an ultrasonic cleaning method and the like are suitably used. Next, typical examples and reference examples of the cleaning action of the flux detergent composition of the present invention will be described, but the present invention is not limited thereto. In addition,% shows weight% unless there is particular notice.

[0012]

EXAMPLES Flux washing test method A solution (30% solution of isopropanol) of solder and flux (polymerized rosin, Arakawa Chemical Industries) was applied to a steel plate (PB-3118, manufactured by Paltex), and the solution was heated at 220 ° C. with a hot blaster. Heat for 20 minutes. The heat-treated steel sheet was immersed in various kinds of cleaning solvents mixed at a predetermined amount at room temperature (23 ° C.), taken out every minute, and the cleaning state was visually observed. The results are summarized in Table 1 (Example) and Table 2 (Comparative Example). In addition, in the following tables, the determination of detergency (28 ° C.) was based on the following criteria. (○) No residue is seen (△) Slight residue is seen (×) Residue is seen

Table 1 Example 1 2 3 4 5 6 Detergent composition (%) HBM 90 80 70 60 60 70 HBA 10 5 5 10 10 10 Water 0 5 10 0 0 0 Isopropanol 0 10 15 10 10 0 Xylene 0 0 0 200 000 Isoamyl acetate 00 000 200 Anisole 0 000 020 Liquid viscosity (mPas) 2.7 2.4 2.4 2.2 2.2 2.3 Surface tension (dyne / cm) 29.2 27.6 27.6 27.5 26.8 29.4 Washing time (min) 5 5 10 3 5 5 Detergency ○ ○ ○ ○ ○ ○ HBM: methyl α-hydroxyisobutyrate HBA: α-hydroxyisobutyric acid

Table 2 Comparative Example 1 2 3 4 5 6 Detergent Composition (%) HBM 0 0 0 0 0 Water 0 0 0 0 0 0 0 Isopropanol 3 0 0 0 0 0 Xylene 70 3 0 0 0 0 0 0 0 0 0 0 0 70 0 0 0 0 0 Cumene 0 0 100 0 0 0 Ethicello 0 0 0 0 0 0 0 1-Dodecane 0 0 0 0 0 0 0 Benzyl alcohol 0 0 0 0 1 0 Tricrene 0 0 0 0 0 0 100 Liquid viscosity (mPa · s) 1.1 0.4 0.7 1.8 2.0 0.6 Surface tension (dyne / cm) 26.2 21.0 28.2 37.1 26.9 29.5 Cleaning time (min) 20 20 20 10 10 5 Detergency × × △ × × × HBM: α-Hydroxyisobutyrate Ethicello: Ethylene glycol mono Ethyl ether trichlene: 1,1,1-trichloroethane

[0015]

According to the flux detergent composition of the present invention, the flux can be satisfactorily washed without leaving the corrosive substance formed by the heat denaturation at the solder joint. Moreover, the earth environment is not destroyed by the conventional chlorine-based solvent, and the operation can be performed safely.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3B201 AA01 AB01 BB01 BB92 CC01 CC21 4H003 DA15 ED02 ED03 ED28 ED29 ED30 ED32 FA01 FA03 FA21

Claims (7)

[Claims] 1. A flux detergent composition comprising α-hydroxyisobutyric acid and α-hydroxyisobutyric acid ester, and free of chlorine and fluorine-based components. 2. The method according to claim 1, wherein α-hydroxyisobutyric acid is contained in an amount of 0.1 to 30.
The flux detergent composition according to claim 1, comprising% by weight. 3. The method according to claim 1, wherein the α-hydroxyisobutyrate is α-hydroxyisobutyrate.
The methyl hydroxyisobutyrate, ethyl α-hydroxyisobutyrate, isopropyl α-hydroxyisobutyrate or butyl α-hydroxyisobutyrate, wherein the α-hydroxyisobutyrate contains 10 to 99.9% by weight. Flux cleaning composition. 4. The composition according to claim 1, which contains 0 to 70% by weight of at least one organic solvent selected from the group consisting of aliphatic and aromatic hydrocarbon compounds, hydroxyl compounds, ketones, ethers and esters. Flux cleaning composition. 5. A detergent composition having a viscosity of 0.3 to 5.0 mP.
The flux detergent composition according to claim 1, which is a · s. 6. A flux detergent composition having a surface tension of 3
The flux detergent composition according to claim 1, wherein the flux detergent composition is 5 dyn / cm or less. 7. A component is soldered on a substrate using a flux, and the flux remaining on the substrate is reduced to a flux containing α-hydroxyisobutyric acid and α-hydroxyisobutyrate and not containing chlorine and fluorine-based components. A method for cleaning a flux, comprising washing with a flux detergent composition, and then rinsing with a liquid that can be easily mixed with the flux detergent composition and does not contain an acidic component.