KR101796112B1 - Cleaning composition for soldering flux residues - Google Patents

Abstract

Provided is a cleaner composition for soldering flux residues comprising a non-ionic surfactant, a complexing agent, an inorganic phosphate compound, a corrosion inhibitor and water. Additionally, provided is a method for removing a solder flux that removes the flux by making the composition be in contact with the solder flux. The composition of the present invention can remove flux residues without causing corrosion of copper, gold, silver, tin, lead, and alloys thereof, which are metal materials of a solder region, by containing each component in an appropriate amount.

Description

[0001] The present invention relates to a cleaning composition for soldering flux residues,

The technique disclosed herein relates to a solder flux residue cleaner composition, and more particularly to a solder flux residue cleaner composition that provides improved cleaning performance without an improved working environment and no corrosion.

Various active and passive component parts are mounted on a printed circuit board on which circuitry is formed by soldering. Particularly, in the case of electronic products requiring various functions such as miniaturization and weight reduction, the density of component mounting increases, and the interval between components to be soldered is narrowed. The solder paste used for soldering is largely composed of solder powder and flux. The function of the flux is to improve the applicability of the solder paste upon soldering and to remove the oxide on the circuit board to be soldered, Thereby improving the bonding property of the resin. The main component of the flux is composed of rosin or rosin derivatives, organic acid, activator and solvent. After the solder is mounted, flux components that have fulfilled the original function are fixed around the part assembly scene. Since the flux adhered includes not only the flux component but also a small amount of solder powder, if the flux cleaning is not performed after the solder mounting, the flux component may be used as a medium in the process of using the electronic product, Flux cleaning is required.

In order to perform such flux cleaning, Korean Patent Laid-Open Publication No. 10-2008-0062129 (published on July 03, 2008) discloses a method for cleaning the surface of a substrate, which is characterized by including a nonionic surfactant, a water-soluble solvent, water, Based detergent composition, but a dangerous substance having a solvent content of flammable substance exceeding 40% may require a preventive facility for use of another dangerous substance. Korean Patent Laid-Open Publication No. 10-2011-0137131 (published on December 22, 2011) discloses a detergent composition comprising a certain amount of an organic amine compound, xylene, a ketone compound and a corrosion inhibitor as a detergent composition for removing solder flux However, it is a dangerous substance having a solvent content of a flammable substance having a low boiling point of more than 40%. In particular, it contains a carcinogenic substance such as xylene, which can cause a fatal problem to the human body.

An object of the present invention is to provide a flux cleaning composition having excellent solder flux residue removal ability without using an organic solvent having a flash point. Another object of the present invention is to provide a detergent composition that does not cause corrosion of copper, gold, silver, tin, lead, and alloys thereof, which are metal materials of the solder region in the flux residue cleaning process.

According to one aspect of the present invention, there is provided a solder flux residue cleaner composition comprising a nonionic surfactant, a complexing agent, an inorganic phosphate compound, a corrosion inhibitor, and water.

According to one embodiment, the solder flux residue cleaner composition comprises 1 to 20 wt% of the nonionic surfactant, 1 to 20 wt% of a complexing agent, 1 to 10 wt% of an inorganic phosphate compound, 1 to 5 wt% of a corrosion inhibitor, And 45 to 85 wt% of water.

According to one embodiment, the nonionic surfactant is selected from the group consisting of polyoxyethylene monomethyl ether, polyoxyethylene monoaryl ether, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene Stearyl ether, polyoxyethylene tridecyl ether, polyoxyethylene octyl ether, polyoxyethylene glycerin ether, and the like.

According to one embodiment, the complexing agent is selected from the group consisting of a carboxylic acid-based complexing agent, an amino acid-based complexing agent, a phosphonic acid-based complexing agent, a phosphoric acid-based complexing agent, an aminocarboxylic acid-based complexing agent and a hydroxycarboxylic acid- It may be more than one kind.

According to one embodiment, the inorganic phosphoric acid compound may be a monobasic, dibasic, or tribasic salt formed by reacting a monovalent metal with phosphoric acid.

According to one embodiment, the corrosion inhibitor may be at least one selected from the group consisting of an organic compound having an azole group, an aromatic hydroxy compound, a sugar alcohol compound, a sulfur compound having a mercapto group, and an amino acid.

According to another aspect of the present invention, there is provided a method of removing solder flux that removes the flux by contacting the composition with a solder flux.

According to one embodiment, the removal of the flux may be performed at a temperature of 20 to 80 ° C for 1 to 30 minutes.

Using the solder flux residue cleaner composition provided in the present invention, the flux residue after soldering can be completely removed.

The composition of the present invention also improves the working environment by cleaning the flux residue without containing a flammable organic solvent.

Further, the composition of the present invention can remove flux residues without causing corrosion of copper, gold, silver, tin, lead, and alloys thereof, which are the metal materials of the solder region, by containing each component in an appropriate amount.

1 shows a printed circuit board before flux cleaning.
Fig. 2 shows an image of the printed circuit board mounted with the flip chip packaging solder ball of Fig. 1 after cleaning using the cleaning composition of Example 1. Fig.
Fig. 3 shows a solder ball image after flux cleaning on the printed circuit board of Fig. 1 with the composition of Comparative Example 2. Fig.
4 shows the solder ball image after cleaning the printed circuit board of Fig. 1 with the composition of Example 1. Fig.

Hereinafter, the present invention will be described in more detail.

The solder flux residue cleaner composition according to one embodiment of the present invention is for cleaning precision parts such as electronic parts, semiconductor parts, etc., which are soldered using solder. The solder may include a metal component and a flux component. Examples of the metal component include copper, gold, silver, tin, lead, and alloys thereof. Preferably, the solder is lead-free solder at all times. For example, the metal component of the lead-free solder includes alloys such as tin-silver, tin-copper, and tin-silver-copper. The flux component includes, but is not limited to, a flux including a base resin, an activator, and a solvent. The base resin may be, for example, rosin, a rosin derivative or the like, and the activator may be, for example, an organic acid, a halide, or the like, and the solvent may be, for example, alcohol.

Examples of the electronic component include a printed board and the like. Examples of the semiconductor component include a semiconductor package and the like.

In this specification, the term "solder flux" refers to the flux component of the solder. However, in the present invention, the solder flux to be removed may contain, in addition to the flux component remaining after soldering, a reaction product of a metal and a flux component contained in the solder, And contaminants derived from the reaction product.

Examples of the reaction product include insoluble tin salts and the like. Particularly, the detergent composition and the cleaning agent of the present invention exert an excellent effect on the removal and reattachment of the insoluble tin salt.

According to one embodiment of the present invention, there is provided a solder flux residue cleaner composition comprising a nonionic surface active agent, a complexing agent, an inorganic phosphoric acid compound, a corrosion inhibitor and water for cleaning the solder flux residue as described above.

The nonionic surfactant serves to improve the rinsability and may be a polyoxyalkylene alkylphenyl ether, a polyoxyalkylene alkyl ether, a polyoxyethylene polyoxypropylene block polymer, a polyethylene glycol fatty acid ester, or a polyoxyethylene sorbitan Fatty acid esters, and the like.

Specifically, the nonionic surfactant is selected from the group consisting of polyoxyethylene monomethyl ether, polyoxyethylene monoaryl ether, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene stearyl ether , Polyoxyethylene tridecyl ether, polyoxyethylene octyl ether, polyoxyethylene glycerin ether, and the like. The nonionic surfactant is preferably contained in an amount of 1 to 20 wt% based on the total composition. If the content is less than 1 wt%, the ability to remove the flux residue may be insufficient. If the content is more than 20 wt%, the rinsing property may deteriorate after cleaning the object to be cleaned.

The complexing agent may be a metal complexing agent capable of coordinating to a metal ion, and may be a complexing agent such as a carboxylic acid complexing agent, an amino acid complexing agent, a phosphonic acid complexing agent, a phosphoric acid complexing agent, an aminocarboxylic acid complexing agent, And a complex acid-based complexing agent.

Examples of the carboxylic acid-based complexing agent include malonic acid, succinic acid, glutaric acid, adipic acid, itaconic acid, acetylsalicylic acid, phthalic acid, trimellitic acid and cyclopentanetetracarboxylic acid. Examples of the amino acid chelating agent include alanine, lysine, arginine, asparagine, tyrosine, and the like. Examples of the phosphonic acid chelating agent include alkylphosphonic acids such as ethylphosphonic acid and octylphosphonic acid, hydroxyethanediphosphonic acid, nitrilotrismethylenephosphonic acid, N, N, N ', N'-tetrakis Methyl) ethylenediamine, and the like. Examples of the phosphate chelate include orthophosphoric acid, pyrophosphoric acid, triphosphoric acid and polyphosphoric acid. Examples of the aminocarboxylic acid chelating agent include ethylenediaminetetraacetic acid (EDTA), cyclohexanediamine tetraacetic acid (CDTA), nitrilotriacetic acid (NTA), diethylenetriamine 5-acetic acid (DTPA) Acetic acid (IDA), N- (2-hydroxyethyl) imino 2-acetic acid (HIMDA), and hydroxyethylethylenediamine 3-acetic acid (HEDTA). Examples of the hydroxycarboxylic acid chelating agent include malic acid, citric acid, isoquinic acid, glycolic acid, gluconic acid, salicylic acid, tartaric acid, and lactic acid.

The complexing agent in the above example may be a salt such as a sodium salt, a potassium salt, an ammonium salt or the like, or a hydrolyzable ester derivative.

As the complexing agent in the present invention, it is preferable to use at least one complexing agent selected from the group consisting of a hydroxycarboxylic acid-based complexing agent, a carboxylic acid-based complexing agent and a phosphoric acid-based complexing agent. Particularly, in view of good solubility in a poorly soluble tin salt or dispersibility of a poorly soluble tin salt which are generated in a soldering process of a lead-free solder, the complexing agent is an ethylene diamine tetraacetic acid disodium salt, ethylenediamine tetraacetic acid 4 Sodium salt, diethylenetetramine monosodium salt, diethylenetetramine trisodium salt, and diethylenetetramine pentasodium salt is preferable.

The complexing agent is preferably contained in an amount of 1 to 20 wt% based on the total composition. If the content is less than 1 wt%, tin ignition of the solder powder component contained in the flux residue may be insufficient, and if it exceeds 20 wt%, the cost incurred by wastewater treatment may increase.

The inorganic phosphoric acid compound serves as a cleaning aid for flux residues. Phosphoric acid compounds are widely known among inorganic compounds as being excellent in degreasing power and have a very excellent role of suppressing dispersion and reattachment of contaminants to be washed. It also has a pH range of weakly alkaline (pH 7 ~ 9), and it also plays a role of preventing corrosion to metal.

The inorganic phosphoric acid compound is a salt formed by reacting a monovalent metal with phosphoric acid, and may be a monobasic, dibasic, or tribasic salt.

The inorganic phosphate compound is selected from the group consisting of potassium phosphate monobasic, potassium phosphate diabase, triphosphate phosphate, potassium phosphate tribase, potassium pyrophosphate, sodium phosphate diacid, sodium phosphate dihydrate, sodium phosphate tribase, sodium phosphate monohydrate, sodium Phosphate decahydrate, and sodium pyrophosphate. In the present invention, The inorganic phosphate compound is preferably contained in an amount of 1 to 10 wt% with respect to the total composition. If the content is less than 1 wt%, the ability to remove the flux residue may be insufficient, and if it exceeds 10 wt%, the cleaning property may already be exceeded, which may be inadequate in terms of economy.

The corrosion inhibitor prevents corrosion of metals (tin, lead, and silver) used in a circuit board and particularly prevents corrosion of metal wiring such as aluminum formed on a circuit board. If metal wiring such as aluminum is corroded, the wiring width may be reduced and the amount of current may be reduced or the performance of the circuit may be deteriorated.

The corrosion inhibitor may be at least one selected from the group consisting of an organic compound having an azole group, an aromatic hydroxy compound, a sugar alcohol compound, a sulfur compound having a mercapto group, and an amino acid. Specifically, organic compounds having an azole group such as benzotriazole, tolythriazole, 4-methylimidazole, 5-hydroxymethyl-4-methylimidazole and 3-aminodiazole; Aromatic hydroxy compounds such as catechol, resorcinol and quinoline; Sugar alcohol compounds such as sorbitol, mannitol, thiazole and xylitol; Dt audio glycerol _{[S (CH 2 CH (OH} ) CH 2 (OH) 2], bis (2,3-dihydroxypropyl thio) ethylene _{[CH 2 CH 2 (SCH 2} CH (OH) CH 2 (OH) _2, 2-mercaptoethanol _{[HSCH 2 CH 2 (OH)} ], 3- mercapto-1-propanol [HSCH ₂ CH ₂ CH ₂ OH], thioglycerol _{[HSCH 2 CH (OH) CH} 2 (OH) , Sulfur compounds having a mercapto group such as thioglycolic acid [HSCH ₂ CO ₂ H], thioacetic acid and thiosalicylic acid, alanine, glutamic acid, aspartic acid, threonine, glycine, phenylalanine, valine, leucine, serine, lysine, Arginine, histidine, tyrosine, tryptophan, proline, and the like.

The printed circuit board to be cleaned is soldered with an alloy such as tin-silver, tin-copper, tin-silver-copper, etc. In consideration of corrosion prevention of tin, which is a main component of the alloy, Do.

The corrosion inhibitor is preferably contained in an amount of 1 to 5 wt%. If the content is less than 1 wt%, the effect of preventing corrosion of the tin or tin alloy may be insufficient. If the content exceeds 5 wt%, the corrosion inhibitor may precipitate and re-adhere to the object to be cleaned.

On the other hand, the nonionic surfactant, the complexing agent, the inorganic phosphate compound and the corrosion inhibitor are dissolved in water and used. By using the above composition in the form of an aqueous solution, nonionic surfactant, complexing agent, inorganic phosphate compound and corrosion inhibitor can be dissolved in water in a stable and uniform form and can be very safe even in the case of fire. Water may be mixed in an amount of 45-85 wt% relative to the total composition. If the amount of water is less than the above range, the additive components may not completely dissolve and some precipitation may occur. If the amount is less than the above range, the additive component may not be contained in an appropriate amount.

According to one embodiment of the present invention, a method of removing flux of solder using the above-described detergent composition is provided. The removal method may be, for example, a method of immersing a circuit board containing a flux in a detergent composition, spraying a detergent composition onto a circuit board, or brushing after a circuit board containing a flux is contacted with a detergent composition or an aqueous solution thereof And so on.

The conditions of use (temperature, time, etc.) of the detergent composition of the present invention are not particularly limited and can be appropriately selected depending on the content and concentration of each component, the kind and concentration of the flux to be removed, and the like. For example, the temperature of the composition at the time of cleaning the object to be cleaned is preferably set appropriately so that the flux to be removed can be suitably washed and removed. The temperature of the detergent composition is usually about 20 to 80 占 폚. By setting the temperature of the composition at 20 占 폚 or higher, the solubility of the flux in the aqueous solution can be improved. In addition, evaporation of water can be suppressed by setting the temperature of the composition to 80 캜 or lower. From these, the preferable range of the temperature of the aqueous solution is about 40 to 70 占 폚.

The time for bringing the aqueous solution into contact with the flux to be removed can be appropriately set in accordance with the temperature of the aqueous solution and the like. For example, when the solder flux on the electronic component is removed by the dipping method using the above aqueous solution at about 60 캜, the flux on the electronic component is satisfactorily improved by immersing the electronic component in the aqueous solution for about 1 to 30 minutes Can be removed. As another example, a printed circuit board with flux residue may be ultrasonically immersed in the composition at 45-55 < 0 > C for 5-10 minutes to clean the flux residue.

After the detergent composition of the present invention is used, a rinsing process may be performed in which a water or alcohol-based solvent is further washed, if necessary.

Hereinafter, the present invention will be described in detail with reference to the following Examples. However, the technical spirit of the present invention is not limited by the following Examples.

[Example]

Soldering was performed under the following conditions to form the flux residue of the present invention.

Solder Paste: Alpha Metal 'ALPHA UP-78'

Solderball: Duksan Hi-Metal Co., Ltd. SAC-305 0.3mm Ball

The above material was coated or mounted on a printed circuit board and heat treated at 250 캜 to form a flux residue.

1 shows a printed circuit board before flux cleaning. 1 (a) is an image of a printed circuit board after the flip chip packaging solder ball is mounted, (b) is an enlarged view of (a), and FIG. 1 (c) shows an image of the printed circuit board after connector mounting. Referring to FIG. 1, in (b), the flux component contained in the solder ball exists in the form of a band around the solder ball after reflow in the solder ball mounting process. It can also be seen that the solder paste is screen printed using a metal mask and that the flux components contained in the solder paste are leaked and adhered between the copper leads after reflow in the connector mounting process .

The flux residues formed thereafter were cleaned as follows and compared in Table 1.

 ≪ Washing condition: 50 占 폚, ultrasonic immersion, washing for 5 minutes, number is wt% division Composition (wt%) Cleaning result Interface
Activator Complexing agent Phosphoric acid
compound corrosion
Inhibitor water Flux removal capability The
causticity Rinseability Solder paste Solder ball Example 1 S1 10 C1 10 P1 5 I1 3 Up to 100wt% ◎ ◎ ◎ ◎ Example 2 S1 15 C1 5 P1 5 I2 3 Up to 100wt% ◎ ◎ ◎ ◎ Example 3 S2 10 C1 5 P1 5 I1 3 Up to 100wt% ◎ ◎ ◎ ◎ Example 4 S2 10 C1 10 P2 5 I1 3 Up to 100wt% ◎ ◎ ◎ ◎ Example 5 S1 5 C1 10 P2 10 I1 3 Up to 100wt% ○ △ ◎ ◎ Example 6 S1 10 C2 10 P2 5 I2 3 Up to 100wt% ◎ ◎ ◎ ◎ Comparative Example 1 S1 25 C1 10 P1 5 I1 3 Up to 100wt% ◎ ◎ ◎ X Comparative Example 2 S1 10 C1 10 P1 5 - Up to 100wt% ◎ ◎ X ◎ Comparative Example 3 - C1 10 P1 5 I1 3 Up to 100wt% X X ◎ ◎

-. S1: polyoxyethylene lauryl ether

-. S2: polyoxyethylene stearyl ether

-. C1: Ethylenediamine tetraacetic di-sodium salt

-. C2: diethylenetetramine trisodium salt

-. P1: tri-potassium phosphate

-. P2: Potassium pyrophosphate

-. I1: alanine

-. I2: Glutamic acid

* Evaluation: ◎ Excellent, ○ Excellent, △ Normal, X Not suitable

Fig. 2 shows an image of the printed circuit board mounted with the flip chip packaging solder ball of Fig. 1 after cleaning using the cleaning composition of Example 1. Fig. Fig. 2 (a) shows an image of the printed circuit board after cleaning, Fig. 2 (b) shows an enlarged image of Fig. 2 (a), and Fig. 2 (c) shows an image of the printed circuit board after cleaning. Referring to FIG. 2, it can be seen that the flux (c) fixed between the solder ball periphery (b) and the connector leads is completely cleaned and removed.

Fig. 3 shows a solder ball image after flux cleaning on the printed circuit board of Fig. 1 with the composition of Comparative Example 2. Fig. Referring to FIG. 3, it can be seen that corrosion of the solder balls occurs as a result of using the detergent composition not containing the corrosion inhibitor.

4 shows the solder ball image after cleaning the printed circuit board of Fig. 1 with the composition of Example 1. Fig. Referring to FIG. 4, using the cleaning composition of the present invention, it can be confirmed that the solder balls are cleanly cleaned without corrosion.

Claims (8)

Nonionic surfactants;
A complexing agent which is at least one selected from the group consisting of a carboxylic acid-based complexing agent, an amino acid-based complexing agent, a phosphonic acid-based complexing agent, a phosphoric acid-based complexing agent and an aminocarboxylic acid-based complexing agent;
Inorganic phosphate compounds;
Corrosion inhibitors; And
Water,
The corrosion inhibitor is a lead-free solder flux residue comprising at least one member selected from the group consisting of alanine, glutamic acid, aspartic acid, threonine, glycine, phenylalanine, valine, leucine, serine, lysine, arginine, histidine, tyrosine, tryptophan and proline Detergent composition. The method according to claim 1,
A lead-free solder flux residue containing 1 to 20 wt% of the nonionic surfactant, 1 to 20 wt% of a complexing agent, 1 to 10 wt% of an inorganic phosphate compound, 1 to 5 wt% of a corrosion inhibitor and 45 to 85 wt% Detergent composition. The method according to claim 1,
The nonionic surfactant may be selected from the group consisting of polyoxyethylene monomethyl ether, polyoxyethylene monoaryl ether, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene stearyl ether, Ethylene decyl ether, ethylene tridecyl ether, polyoxyethylene octyl ether, polyoxyethylene glycerin ether, and the like. The method according to claim 1,
Wherein said complexing agent is selected from the group consisting of ethylenediaminetetraacetic acid disodium salt, ethylenediamine tetraacetic tetrasodium salt, diethylenetetramine monosodium salt, diethylenetetramine trisodium salt and diethylenetetramine pentasodium salt. At least one lead-free solder flux residue cleaner composition. The method according to claim 1,
Wherein the inorganic phosphoric acid compound is a salt formed by reacting a monovalent metal with phosphoric acid and is a monobasic, dibasic, or tribasic salt. delete 6. A method of removing a lead-free solder flux according to any one of claims 1 to 5, wherein the flux is removed by contacting the lead-free solder flux. 8. The method of claim 7,
Wherein the removal of the flux is performed at a temperature of 20 to 80 DEG C for 1 to 30 minutes.

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