KR101128865B1 - Formulation of cleaner for removing residual flux after reflow and cleaning method by using it - Google Patents

Abstract

PURPOSE: A cleaner composition for flux residues which follows a reflow process and a cleaning method using thereof are provided to be able to apply in various cleaning methods including a spray cleaning, a deposition washing, and a ultrasonic cleaning. CONSTITUTION: A cleaner composition for flux residues comprise: 60-90 weight% of hydrophilic solvent including chemical compound marked as chemical formula 1: CmH(2m+1)-O-(CH2CH2O)n-OH or as chemical formula 2: CxH(2x+1)-O-(CH 2CH(CH 3)O)y-OH, or a mixture thereof; 0.1-10 weight% of a surfactant including chemical compound marked as chemical formula 3: R-O-(CH2CH2O)k-(CH2CH(CH3)O)��H; 0.1-5 weight% of aiding agent; and 1-30 weight% of water. In the chemical formula1, 2, and 3, M indicates integer of 1-4, N indicates integer of 1-5, X indicates integer of 1-4, Y indicates integer of 1-3, R indicates C1-15 alkyl group, K indicates integer of 3-15, ��indicates integer of 3-15, and ratio of k/��is 0.5-2.

Description

Flux residue cleaning agent composition according to the reflow process and cleaning method using the same {Formulation of cleaner for removing residual flux after reflow and cleaning method by using it}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning composition used for cleaning residual fluxes generated after reflow of an electrical / electronic component production process or a surface mount technology (SMT) or surface mount device (SMD) process, and more specifically, a hydrophilic solvent, Detergent composition comprising a surfactant, an adjuvant and water.

Recently, the flux or flux cream used in the electronics and electronics industry, SMT and SMD processes is a technology for replacing harmful substances such as lead (Pb) and chlorine (Cl). Development is actively underway, and production of parts that need to be cleaned after the reflux process is gradually expanding. The cleaning agents used are 1,1, and 1 containing chlorine (Cl), which has a good solubility because pollutants are generated at 180 ~ 240 ℃ temperature conditions in the reflow process, so the adhesion state to the object to be cleaned is very strong. 1-TCE, CFC 113, MC, PCE, TCE and the like have been used, the cleaning agents have been used in the industrial field for a long time because of the advantages of excellent cleanability, flammability and excellent volatility. However, the cleaning agents are poor in material safety to the object to be cleaned and are regulated domestically and internationally as ozone depleting substances, thus limiting their use and gradually replacing them with environmentally friendly cleaning agents. In particular, the cleaning agents such as MC, PCE, TCE, etc. among the cleaning agents are defined as carcinogenic substances, and researches on the development of various cleaning agents that can replace them recently have been conducted.

Alternative cleaners can be broadly classified into alcohol-based and hydrocarbon-based cleaners, water-based cleaners and semi-detergent cleaners.

The alcohol-based and hydrocarbon-based cleaners have the advantage of being free of water and similar drying properties compared to chlorine-based cleaners, so that they can be used without changing the conventional cleaning system, but the cleaning performance is relatively low, and residual flux or whitening is present. It is not suitable for cleaning the heat-hardened fluxes, and has a low flash point, which is a risk of fire. In addition, some chemicals, such as IPA, are defined as volatile organic compounds (VOCs), requiring cleaning equipment supplementation or limited use.

Most water-based cleaners do not contain ozone depleting substances and carcinogenic substances. In particular, alkaline cleaning agents containing KOH, NaOH, inorganic builders and the like can be efficiently used for cleaning the flux. However, since the corrosion of metal materials such as gold, silver, copper, aluminum, and zinc among the materials of the electrical and electronic parts according to the alkali characteristics has a disadvantage in that the scope of cleaning is limited.

The compliant cleaner is highly soluble and has excellent cleaning ability, and is considered to be an alternative cleaner for ozone depleting substances and carcinogenic substances. However, when the main composition of the cleaning agent is an oil, in particular, in the case of an oil having 14 to 20 carbon atoms, since the continuous phase of the cleaning composition is an oil, the mixing property with water is poor in the rinsing process, and a macro emulsion is formed. For this reason, rinsability is inferior compared with an aqueous detergent, and it is reported that the cleaning composition may remain in the to-be-cleaned object after washing | cleaning. In particular, if the main product of the detergent is limonene oil, the mixing properties with water are poor, so that the rinsing performance is poor in the rinse process, and thus the source of contamination remains.

Accordingly, the present inventors have conducted research and efforts to develop an alternative cleaning agent that can solve the above problems, (a) a hydrophilic solvent which is a compound represented by the following formula (1) or (2), or a mixture thereof, (b) The present invention has been completed by discovering that detergent compositions comprising the compounds represented, (c) adjuvants and (d) water, are very effective in flux removal.

[Formula 1]

C _m H _{2m +1} -O- (CH ₂ CH ₂ O) _n -OH

[Formula 2]

C _x H _{2x +1} -O- (CH ₂ CH (CH ₃ ) O) _y -OH

(3)

RO- (CH ₂ CH ₂ O) _k- (CH ₂ CH (CH ₃ ) O) _l -H

Therefore, in the present invention, in the cleaning of residual flux generated after the reflow of the electrical / electronic parts production process or the SMT and SMD process, it replaces the conventional chlorine-based cleaner and has excellent rinsing performance and no residual pollutant after cleaning. Its purpose is to provide a cleaning agent which does not remain and has a high flash point which lowers the risk of fire.

The present invention

(a) 60 to 90% by weight of a hydrophilic solvent which is a compound represented by the following Chemical Formula 1 or the following Chemical Formula 2, or a mixture thereof;

(b) 0.1 to 10 wt% of a surfactant comprising a compound represented by the following Formula 3;

(c) 0.1 to 5 weight percent of adjuvants; And

(d) 1 to 30% by weight of water

It is characterized by a flux composition for cleaning flux comprising a.

[Formula 1]

C _m H _{2m +1} -O- (CH ₂ CH ₂ O) _n -OH

[Formula 2]

C _x H _{2x +1} -O- (CH ₂ CH (CH ₃ ) O) _y -OH

(3)

RO- (CH ₂ CH ₂ O) _k- (CH ₂ CH (CH ₃ ) O) _l -H

In Formula 1, m is an integer of 1 to 4, n is an integer of 1 to 5,

In Formula 2, x is an integer of 1 to 4, y is an integer of 1 to 3,

In Formula 3, R is an alkyl group of C ₁ ~ C ₁₅ , k is an integer of 3 to 15, l is an integer of 3 to 15, the ratio of k / L is 0.5 to 2.

The flux composition for cleaning flux of the present invention is excellent in cleaning performance of residual flux generated after reflow of an electronic or electronic parts production process or SMT and SMD process, and has a low foaming characteristic, so that it is spray cleaning, deposition cleaning, and ultrasonic wave. It can be easily applied according to various cleaning methods such as cleaning.

1 is a photograph showing the object to be cleaned before and after washing with the composition of Example 1.

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

The present invention is (a) a hydrophilic solvent which is a compound represented by the following formula (1) or (2), or a mixture thereof, (b) a surfactant comprising a compound represented by the following formula (3), (c) adjuvants and (d) water Characterized by the flux composition for cleaning fluxes included.

[Formula 1]

C _m H _{2m +1} -O- (CH ₂ CH ₂ O) _n -OH

[Formula 2]

C _x H _{2x +1} -O- (CH ₂ CH (CH ₃ ) O) _y -OH

(3)

RO- (CH ₂ CH ₂ O) _k- (CH ₂ CH (CH ₃ ) O) _l -H

First, the components of the hydrophilic solvent, which is one of the main constituents of the flux removal detergent composition of the present invention, should be selected from solvents having high solubility, low odor, and good environmental and human safety for flux. , The compound represented by the following formula (1) or (2), or a mixture thereof is used.

[Formula 1]

C _m H _{2m +1} -O- (CH ₂ CH ₂ O) _n -OH

[Formula 2]

C _x H _{2x +1} -O- (CH ₂ CH (CH ₃ ) O) _y -OH

In Formula 1, m is an integer of 1 to 4, n is an integer of 1 to 5,

In Formula 2, x is an integer of 1 to 4, y is an integer of 1 to 3.

Representative examples of the compound represented by Formula 1 include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, polyethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, Ethylene glycol solvents such as triethylene glycol monoisobutyl ether or diethylene glycol monoisobutyl ether, or any mixture thereof may be used. Representative examples of the compound represented by Formula 2 include propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, propylene glycol monobutyl ether, Propylene glycol solvents such as dipropylene glycol monobutyl ether and the like or any mixture thereof can be used. More preferably, any mixture of the compound represented by the formula (1) and the compound represented by the formula (2) may be used. In addition to the above compounds, solvents such as ethylene glycol monohexyl ether, ethylene glycol monoally ether, propylene glycol monomethyl ether acetate, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether may be further included as hydrophilic solvents. The hydrophilic solvents described above are used in the range of 60 to 90% by weight, preferably 70 to 80% by weight, based on the total composition.

Next, the surfactant, which is one of the main constituents of the cleaning composition of the present invention, will be described. The non-ionic surfactant is preferably used because the foamability is low and the residual of the ionic substance in the object to be cleaned is not preferable. Do. Nonionic surfactants play a role of increasing the penetration of the cleaning agent between the cleansing material and the pollutant in the cleaning process, and in the rinsing process, micelles are formed to prevent the contamination of the contaminant from the cleansing material to be reattached to the cleansing object. Play a role. As the nonionic surfactant, a compound represented by the following Chemical Formula 3 in which ethylene oxide and propylene oxide are added to an alkyl group is used.

(3)

RO- (CH ₂ CH ₂ O) _k- (CH ₂ CH (CH ₃ ) O) _l -H

In Formula 3, R is an alkyl group of C ₁ ~ C ₁₅ , k is an integer of 3 to 15, l is an integer of 3 to 15, the ratio of k / L is 0.5 to 2.

In the present invention, the surfactant is a polyoxyalkylene alkyl phenol ether, polyoxyalkylene aryl phenol ether, polyoxyalkylene fatty acid ester, polyoxyalkylene sorbitan fatty acid ester, polyoxyalkyl in addition to the compound represented by the above formula (3) Lene alkyl amine, sorbitan fatty acid ester, alkyl alcohol amine, aryl alcohol amine, or any mixture thereof.

In the present invention, the surfactant is used in the range of 0.1 to 10% by weight, preferably 1 to 5% by weight based on the total composition.

Next, the adjuvant which is one of the main components of the cleaning composition of this invention is demonstrated. The auxiliary agent serves to improve the cleaning performance of the cleaning agent or to prevent corrosion of the object to be cleaned and to prevent reattachment of the pollutant.

Examples of the adjuvant include potassium pyrophosphate, calcium carbonate, sodium carbonate, Na silicate, Na gluconate, 4Na-EDTA, citric acid, salicylic acid, malonic acid, succinic acid, glutaric acid, pyrophosphoric acid, polyphosphoric acid, benzotriazole, sorbitol, glucose, One or a mixture of two or more selected from the group consisting of carboxylic benzotriazole, tolytriazole, diethanolamine, triethanolamine, monoisopropanolamine and diisopropanolamine can be used. The adjuvant is used in the range of 0.1 to 5% by weight, preferably 0.5 to 3% by weight, based on the total composition.

In addition, the water included in the cleaning composition of the present invention is used in the range of 1 to 30% by weight, preferably 2 to 20% by weight based on the total composition.

The cleaning agent of the present invention has a physical property in the range of the surface tension of 28 ~ 30 dyne / cm (25 ℃), viscosity of 4 ~ 7 cP (25 ℃), specific gravity 0.94 ~ 0.98 (25 ℃).

The preparation of the cleaning composition of the present invention can be obtained by mixing in a conventional manner, but it is preferable to first mix water with the adjuvant, and then mix the hydrophilic solvent with the mixture thereof, and finally, mix the surfactant. However, the preparation of the cleaning composition of the present invention is not limited thereto, and may be mixed in any order, all at the same time, or some may be mixed at the same time.

The cleaning composition of the present invention can be used for cleaning the residual flux generated after the reflow of the electrical and electronic component production process, or SMT, SMD process, simple deposition cleaning, ultrasonic cleaning, spray cleaning, vibration cleaning, bubbling cleaning Various cleaning methods, such as can be applied. In addition, it is possible to apply the optimum cleaning conditions by adjusting the cleaning time, cleaning temperature, rinsing time, rinsing temperature and the like.

Hereinafter, the present invention will be described in more detail with reference to examples, but the following examples are merely to illustrate the present invention, but it should be understood that the present invention is not limited thereto.

Example  1 to 11 and Comparative example  1 to 5

Preparation of Cleans and Contaminants:

Epoxy-coated PCB (printed circuit board) was prepared as the object to be cleaned in a size of 7.0 × 2.0 × 0.2 cm ³ . A solder paste (TAMURA / SQ-10-137H) was printed in a predetermined pattern using a metal mask on the object to be cleaned, and soldering was performed at 230 ° C. for 2 minutes in a heating furnace. Thereafter, the specimen was left at room temperature for 1 hour and stored in the desiccator for at least 1 hour as a test specimen.

Cleaning method:

50 ml of the cleaning composition prepared at the composition ratios shown in Tables 2 and 3 were placed in a measuring cylinder, and the washing was performed by simply depositing the object to be cleaned for 2 minutes in a thermostatic bath at 60 ° C. Thereafter, the object to be cleaned was taken out, and then simply immersed in a measuring cylinder filled with 50 ml of 60 ° C. pure water for 2 minutes, and a rinsing process was performed. The rinsing process was repeated three times, and finally, the product to be rinsed three times was taken out, dried in an oven maintained at 70 ° C. for 5 minutes, and the cleaning performance of the cleaning composition was evaluated.

Method for evaluating performance of detergent composition:

Various methods can be applied to the detergent performance evaluation according to the type and characteristics of the object to be cleaned, the type and characteristics of the pollutant, but in the present invention, the performance of the detergent composition was evaluated as shown in Table 1 below, and the results are shown in Tables 2 and 3 below. Shown in

Stability ◎: There is no sediment in the cleaner, and the color is clear (Circle): There is little sediment in a detergent, and a color is clear. (Triangle | delta): There are some deposits in a detergent, and a color is clear or normal Ｘ: Detergent in the detergent, blurry color, or forming a separate layer Cleaning performance (Double-circle): There is no contamination of a contamination source in a test specimen, and it is very favorable (Circle): The test specimen has little residue of a contamination source, and is favorable (Triangle | delta): There exists some residue of a contamination source in a test specimen, and is bad Ｘ: Poor source of test specimen remains Bubble ◎: Bubble completely disappears within 1 minute ○: bubbles disappear completely within 3 minutes △ bubble completely disappears within 5 minutes Ｘ: bubbles remain for more than 5 minutes

Component (wt%) Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Diethylene glycol monobutyl ether 70 80 30 40 50 50 Dipropylene glycol monobutyl ether 70 80 50 40 30 30 Ethylene Glycol Monohexyl Ether A 2.5 2.5 2.5 2.5 2.5 2.5 2.5 B 2.5 C 4Na-EDTA 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Triethanolamine Benzotriazole water Balance Balance Balance Balance Balance Balance Balance Balance Sum 100 100 100 100 100 100 100 100 Phase stability (60 ℃) ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ Cleaning performance ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ Bubble ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎

Component (wt%) Example 9 Example 10 Example 11 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Diethylene glycol monobutyl ether 50 50 50 50 50 50 50 50 Dipropylene glycol monobutyl ether 30 30 30 30 30 30 Ethylene Glycol Monohexyl Ether 30 A B 2.5 2.5 2.5 2.5 2.5 2.5 C 2.5 3.0 4Na-EDTA 0.3 0.3 0.3 0.3 5 Triethanolamine 0.3 Benzotriazole 0.3 water Balance Balance Balance Balance Balance Balance Balance Balance Sum 100 100 100 100 100 100 100 100 Phase stability (60 ℃) ◎ ◎ ◎ ◎ Ｘ ◎ Ｘ ◎ Cleaning performance ◎ ◎ ○ Ｘ Ｘ △ ◎ Ｘ Bubble ○ ◎ ◎ ◎ ◎ Ｘ ◎ ◎

* In Tables 2 and 3, A, B and C are compounds represented by Chemical Formula 3, R is an alkyl group having 12 carbon atoms, and the ratio of k / L is 0.5 for A, 1.0 for B, and 2.5 for C.

As shown in Tables 2 and 3, the compositions of Examples 1 to 11, which are the cleaning composition of the present invention, were all excellent in phase stability, cleaning performance, and foaming. In particular, it showed excellent cleaning performance even in simple deposition, and it was confirmed that the cleaning time can be shortened in the spray cleaning and ultrasonic cleaning methods.

The composition of Comparative Example 1 was found to be inferior in cleaning performance as compared to the example, it is due to the relatively low content of hydrophilic solvents, solubility in the pollutant. The composition of Comparative Example 2 was a case in which a hydrophobic solvent was used, in which phase stability was inferior and the cleaning composition was separated into a hydrophilic layer and a hydrophobic layer. The composition of Comparative Example 3 showed a tendency to increase the foamability relatively by increasing the content of the ethylene oxide group in the surfactant compound, it was confirmed that the detergent residues in the object to be washed after cleaning. And the composition of Comparative Example 4, the cleaning performance was good by greatly increasing the content of the auxiliary, the problem appeared that the precipitate occurs in the cleaning composition. Finally, the composition of Comparative Example 5 does not contain an adjuvant, the cleaning performance is significantly lowered and a problem that a large amount of residual contaminants are observed in the object to be cleaned after cleaning appeared.

1 is a photograph before and after washing with the composition of Example 1, the flux residue is observed in the object to be cleaned before cleaning, after the cleaning it was confirmed that the contamination source including the flux residue was removed.

Therefore, it was confirmed that the cleaning composition of the present invention was a cleaning composition for flux removal having excellent cleaning ability and phase stability and no bubbles.

Claims (8)

(a) 60 to 90% by weight of a hydrophilic solvent comprising a compound represented by the following formula (1) or (2), or a mixture thereof;
(b) 0.1 to 10 wt% of a surfactant comprising a compound represented by the following Formula 3;
(c) 0.1 to 5 weight percent of adjuvants; And
(d) 1 to 30% by weight of water
Flux cleaning agent composition comprising a.
[Formula 1]
C _m H _{2m +1} -O- (CH ₂ CH ₂ O) _n -OH
(2)
C _x H _{2x +1} -O- (CH ₂ CH (CH ₃ ) O) _y -OH
(3)
RO- (CH ₂ CH ₂ O) _k- (CH ₂ CH (CH ₃ ) O) _l -H
In Formula 1, m is an integer of 1 to 4, n is an integer of 1 to 5,
In Formula 2, x is an integer of 1 to 4, y is an integer of 1 to 3,
In Formula 3, R is an alkyl group of C ₁ ~ C ₁₅ , k is an integer of 3 to 15, l is an integer of 3 to 15, the ratio of k / L is 0.5 to 2.
According to claim 1, wherein the compound represented by Formula 1 is ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, polyethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol mono Cleaner composition, characterized in that butyl ether, triethylene glycol monoisobutyl ether or diethylene glycol monoisobutyl ether.
According to claim 1, wherein the compound represented by Formula 2 is propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, propylene glycol mono Detergent composition, characterized in that it is butyl ether or dipropylene glycol monobutyl ether.
The method of claim 1, wherein the hydrophilic solvent of (a) is selected from the group consisting of ethylene glycol monohexyl ether, ethylene glycol monoally ether, propylene glycol monomethyl ether acetate, ethylene glycol dimethyl ether and diethylene glycol dimethyl ether. The cleaning composition comprising a species or a mixture of two or more kinds.
The method of claim 1, wherein the surfactant of (b) is polyoxyalkylene alkyl phenol ether, polyoxyalkylene aryl phenol ether, polyoxyalkylene fatty acid ester, polyoxyalkylene sorbitan fatty acid ester, polyoxyalkylene A cleaning composition comprising one or more mixtures selected from the group consisting of alkyl amines, sorbitan fatty acid esters, alkyl alcohol amines and aryl alcohol amines.
According to claim 1, wherein the adjuvant of (c) is potassium pyrophosphate, calcium carbonate, sodium carbonate, Na silicate, Na gluconate, 4Na-EDTA, citric acid, salicylic acid, malonic acid, succinic acid, glutaric acid, pyrophosphoric acid, poly Phosphoric acid, benzotriazole, sorbitol, glucose, carboxylic benzotriazole, tolytriazole, diethanolamine, triethanolamine, monoisopropanola and diisopropanolamine Cleaner composition, characterized in that.
A method for cleaning and removing residues of flux after a reflow process, wherein the cleaning composition according to any one of claims 1 to 6 is used.
8. The method of claim 7, wherein the object to be cleaned is cleaned by simple deposition, ultrasonic cleaning or spray cleaning.

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