KR100907568B1 - Cleaning agent for removing solder flux and method for cleaning solder flux - Google Patents

Abstract

A cleaning agent for removing solder flux is provided to remove an ion part and a resin part in flux when removing residues in electronic parts after soldering, and to prevent environmental contamination. A cleaning agent for removing solder flux comprises an alkoxy alkyl alcohol 20~60 weight% of chemical formula I: CNH_(2N+1)-O-R-C_MH_(M-1)-OH and an alkoxy propanol of chemical formula II: C_LH_(2L+1)-(CH2CHCH3O)_K-OH. In chemical formula I, R is C0~C4 alkyl group; N is an integer of 1-4; and M is an integer of 1-4. In chemical formula II, L is an integer of 1-4 and K is an integer of 1-3. The alkoxy alkyl alcohol of chemical formula I and alkoxy propanol of chemical formula II are used in a ratio of 25 : 75 - 75 : 25.

Description

Cleaning agent for removing solder flux and method for cleaning solder flux}

The present invention relates to a solder flux removal cleaner and a solder flux cleaning method, and the present invention also relates to a lead-free solder flux removal cleaning composition and a lead-free solder flux cleaning method.

In the manufacture of precision parts such as electronic components, soldering is usually performed, and the solder is a mixed salt used to make a thin layer of salts dissolved on the surface of the metal for the purpose of preventing the molten metal surface from contacting the atmosphere. Flux is included. The flux cleans the soldered object and the surface of the solder and prevents reoxidation during soldering.It can be used for basic materials such as rosin and rosin derivatives, organic acids (oleic acid, lactic acid, etc.), inorganic materials (zinc chloride), and organic-inorganic complexes. It consists of a solvent, such as an activator, and alcohol for flux viscosity adjustment. Among the main components of the flux, the solvent is volatile and vaporizes, and the base material and the active agent remain as residues. When the active agent included in the water-soluble flux comes into contact with moisture in the air, it becomes white and gradually corrodes the junction. This happens.

After soldering, a cleaning process is performed to remove excess solder flux present on the surface of the part. For this cleaning process, a chlorine-based cleaner is conventionally used, but these chlorine-based cleaners are used to clean environmental problems, toxicity, and ions. There are problems such as not being able to.

On the other hand, in recent years, lead-free solder using copper, silver, and the like instead of lead is used. In the case of using lead-free solder, many reaction products such as activators and tin salts, rosin and salt salts, etc., are used during the soldering process. There is a tendency to occur, and these reaction products are hardly dissolved in various solvents, cleaning agents and the like and are difficult to remove.

The cleaning agent for removing such solder flux is substantially free of water and a surfactant, and the cleaning agent for removing solder flux containing a glycol compound, benzyl alcohol and amino alcohol (Korean Patent Application No. 10-2007-7001884) ), A cleaning composition for removing lead-free solder flux containing a polyoxyalkylene phosphate ester-based surfactant, a metal chelating agent, and a non-halogen-based organic solvent (Korean Patent Application No. 10-2008-7021802).

In the present invention, in the removal of flux residues after soldering in electronic components, especially printed circuit boards, the ions and resins in the flux are simultaneously removed and do not affect the materials and insulation used in the electronic components, and also have no environmental pollution. An object of the present invention is to provide a high-performance solder flux removal agent composition having excellent quality and a method for cleaning the flux after soldering. Moreover, an object of this invention is to provide the cleaning composition for lead-free solder flux removal, and the flux cleaning method after lead-free solder. In particular, it is an object of the present invention to provide a cleaning composition for a lead-free solder flux removal for flip chips and a flux cleaning method.

When bubbles are generated due to the use of cleaning agents, there are many problems in the production line due to pressure changes. The present invention also aims to provide a low foaming detergent composition for removing solder flux.

The inventors of the present invention have completed the present invention by developing a cleaning composition and a cleaning method for removing solder or lead-free solder flux that can achieve the above object.

In one aspect, the invention provides a detergent composition for solder flux removal comprising an alkoxy alkyl alcohol of formula (I) and an alkoxy propanol of formula (II).

[Formula I]

C _N H 2 _{N +1} -ORC _M H _{M -1} -OH

In the general formula (I), R is an alkyl group of C ₀ to C ₄ , N is an integer of 1 to 4, M is an integer of 1 to 4.

[Formula II]

C _L H _{2L +} 1-(CH ₂ CHCH ₃ O) _K -OH

In Chemical Formula II, L is an integer of 1 to 4, K is an integer of 1 to 3.

The cleaning composition for solder flux removal of the present invention is particularly useful for lead-free solder flux removal.

Examples of the alkoxy alkyl alcohol of the formula (I) include methoxy ethanol, ethoxy ethanol, proxy ethanol, butoxy ethanol, methoxy propanol, ethoxy propanol, proxy propanol, butoxy propanol, methoxy butanol, ethoxy butanol, methoxy methyl Propanol, methoxy methyl butanol, and the like.

Examples of the alkoxy propanol of Formula II include propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether and the like.

The alkoxy alkyl alcohol compound of the formula (I) is easy to optimize the solubility parameter of the cleaning agent, has excellent cleaning properties, retains rinsing properties, exhibits stability of the cleaning liquid, and can further reduce dielectric loss on the surface of the substrate. have. Although the alkoxy alkyl alcohol compound of the formula (I) has excellent washing ability alone, the effect is maximized when used in combination with the alkoxy propanol of the formula (II). The amount of the alkoxy alkyl alcohol compound of general formula (I) is preferably in the range of 20 to 60% by weight based on the total weight of the detergent composition of the present invention.

The alkoxy propanol compound of Formula II is also easy to optimize the solubility parameter of the cleaning agent, has excellent cleaning properties, retains rinsing properties, exhibits stability of the cleaning solution, and can further reduce dielectric loss on the substrate surface. In addition, it is a relatively less odorous and environmentally stable compound than ethylene-based. The alkoxy propanol compound of Formula II also has excellent washing ability alone, but when used in combination with the alkoxy alkyl alcohol of Formula I, the effect is maximized. The amount of the alkoxy propanol compound of formula II is preferably in the range of 20 to 60% by weight based on the total weight of the detergent composition of the present invention.

In the cleaning composition of the present invention, the alkoxy alkyl alcohol of the formula (I) and the alkoxy propanol of the formula (II) may be used in a ratio range of 25:75 to 75:25. In the ratio of alkoxy alkyl alcohol to alkoxy propanol, the detergency is relatively low when the alkoxy alkyl alcohol is used in an amount of less than 25% or more than 75%, and also relatively detergency when the alkoxy propanol is used in an amount of less than 25% or more than 75%. It is undesirable to fall off.

The total content of the alkoxy alkyl alcohol and the alkoxy propanol is preferably in the range of 30 to 90% by weight based on the total weight of the cleaning composition of the present invention, and when the total content of these compounds is less than 30% by weight of the cleaning composition, the cleaning power is lowered and the weight is 90%. Exceeding% does not exert more effect.

The solder composition for removing solder flux of the present invention further comprises an amine compound and an alcohol compound in addition to the alkoxy alkyl alcohol of the formula (I) and the alkoxy propanol of the formula (II).

The amine compound in the solder flux removal cleaning composition of the present invention serves to break the chain by weakening the carbon bond of the organic binder. Specifically, the cured resin and the rosin-based bond strength is weakened. When used in combination with organic solvents and alcohols, the effect is much better. It should be used in combination with alcohol and its amount is preferably used in the range of 5% by weight to 15% by weight based on the total weight of the detergent composition of the present invention, it is not effective when used in less than 5% by weight, 15% by weight When used in an amount exceeding it does not exert more effect.

Examples of amine compounds that can be used in the present invention include ethanolamine, diethanolamine, triethanolamine, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, n-propylamine, di-n -Propylamine, tri-n-propylamine, isopropylamine, di-isopropylamine, tri-isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, etc. are mentioned. .

In the solder flux removal cleaning composition of the present invention, the alcohol compound is combined with an amine compound to improve saponification or penetration by alkaline action, and also to electrical neutralization power, thereby improving cleanability of certain flux residues and the like. It should be used in combination with an amine, and the amount of the amine should be used in the range of 1% by weight to 10% by weight based on the total weight of the cleaning composition of the present invention. When used in an amount exceeding it does not exert more effect.

Examples of alcohol compounds that can be used in the present invention include methanol, ethanol, propanol, isopropanol, butanol, 2-butanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, methyl propanol, methyl butanol , Trifluoroethanol, allyl alcohol, 1-hexanol, 2-hexanol, 3-hexanol, 2-ethyl hexanol, 1-pentanol, 1-octanol, 1-decanol, 1-dodecanol, Cyclohexanol, cyclopentanol, ethylene glycol, propylene glycol, butylene glycol, and mixtures thereof.

Solder flux removal cleaning composition of the present invention can be used to clean the bump ball material can be used for Sn / Pb or lead-free material (Sn 96.5 / Cu 3 / Ag 0.5), in particular lead frame It is effective for flux cleaning after high temperature reflow process of materials, and it is excellent in lead-free solder flux cleaning effect for flip chip.

In addition, the cleaning composition of the present invention is excellent in the cleaning effect in the material having a chip and board gap or bump ball size of 60 micrometers or more, the reliability after the cleaning process meets the JEDEC (Joint Electron Device Engineering Council) Level 3 regulations.

Conventional flux detergent compositions use a lot of ethylene glycol, but the detergent composition of the present invention is environmentally suitable as propylene glycol.

In addition, there are many problems such as pressure change in the production line when bubbles are generated due to the use of the cleaning agent, a large number of flux cleaning compositions used in the prior art had a problem that the spray pressure change occurs because of the large foaming in the actual production line. However, the composition of the present invention has little foaming. In the foam evaluation experiment, the commercial product takes 6 to 7 minutes to remove the foam, whereas the cleaning composition of the present invention was evaluated to have low foamability by removing the foam within 2 minutes.

In another aspect, the present invention provides a method for cleaning and removing residues of flux after soldering. In particular, the present invention provides a method for cleaning flux after lead-free solder.

The cleaning method of the present invention includes using the above-described cleaning agent for solder flux removal containing the alkoxy alkyl alcohol of the formula (I) and the alkoxy propanol of the formula (II).

[Formula I]

C _N H 2 _{N +1} -ORC _M H _{M -1} -OH

In the general formula (I), R is an alkyl group of C ₀ to C ₄ , N is an integer of 1 to 4, M is an integer of 1 to 4.

[Formula II]

C _L H _{2L +} 1-(CH ₂ CHCH ₃ O) _K -OH

In Chemical Formula II, L is an integer of 1 to 4, K is an integer of 1 to 3.

Examples of the alkoxy alkyl alcohol of the formula (I) and the alkoxy propanol of the formula (II) are as described above in connection with the flux composition for cleaning flux of the present invention.

The flux composition and the cleaning method of the present invention are excellent in cleanability in removing flux residue after soldering in an electronic component, and simultaneously remove ions and resins in the flux, and use materials and materials for the electronic component. It does not affect the insulation, there is no environmental pollution, and there is almost no generation of bubbles that cause problems such as pressure change in the production line.

Hereinafter, embodiments of the present invention will be described in more detail with reference to Examples. However, the following examples are provided for the purpose of illustration and should not be construed as limiting the invention to the scope of the following examples.

Example  1-15

Flux  Preparation and Detergency Evaluation of Detergent Composition

As shown in Table 1 below, the flux composition for cleaning flux of the present invention was prepared.

In order to evaluate the cleaning power of the prepared detergent composition, first, as a material to be treated with a detergent, a 20-fold magnification microscope was used on a material (bump surface: Sn 96.5 / Cu 3 / Ag 0.5) subjected to a 245 ° C. reflow process after flux treatment. The full range bleaching phenomenon was confirmed. The substrate size was 30 x 30 mm 2 and the flip chip size was 6.68 x 12.49 mm 2 (total bump number: 1,091 EA).

The composition of the Example was diluted to 20% by volume in water to evaluate the cleaning power and the degree of bubble generation at a temperature of 40 ℃ 10 minutes (spray). In the case of the immersion treatment, the substrate was treated for 10 minutes in a 10 L detergent composition diluent in a bath and circulator equipped with a temperature controller to maintain 40 ° C. to evaluate the cleaning power and the degree of bubble generation. In the case of the type, it was treated with 200 L of detergent composition diluent for 5 minutes at a spray nozzle pressure of 9-12 kgf / cm 2 in baths and circulators with a temperature controller to maintain 40 ° C.

After the treatment of the cleaning composition, it was washed twice and dried with hot air.

In order to confirm the cleaning power, the flip chip top portion was heated for 10 minutes with a 250 ° C. heat gun, and then, after the flip chip was removed, the cleaning power was observed through a 20 magnification microscope to confirm the cleaning power through the cleaning range or the whitening residual range. Bubbles measured the height (cm) of bubbles remaining on top of the solution in the case of spray type detergency evaluation in a 200 L tank.

The results were evaluated by dividing the whole area observed under the microscope into 64 to evaluate the cleaning power. Evaluation criteria are shown in Table 2, the results are shown in Table 1.

Moreover, in order to confirm whether the washing | cleaning agent component remains after the process of cleaning composition, the peak was confirmed on the surface of the board | substrate before and behind a process using FT-IR. The results are shown in Figures 3A and 3B. 3A is a substrate before treatment, and 3B is a substrate after treating and washing the composition of Example 1. FIG.

Comparative example  1-5

Flux  Preparation and Detergency Evaluation of Detergent Composition

The flux composition for flux removal of Comparative Examples 1 to 5 was prepared as shown in Table 1 below.

The cleaning power was evaluated in the same manner as in the above example. The results are shown in Table 1.

Comparative example  6

Evaluation of cleaning power of commercial products

A commercially available flux cleaner product (Company A) was used as Comparative Example 6, and the cleaning power was evaluated in the same manner as in Example. The results are shown in Table 1.

A-1: methoxy methyl propanol

A-2: methoxy methyl butanol

A-3: tetrahydrofurfuryl alcohol

B-1: Tripropylene Glycol Methyl Ether

B-2: tripropylene glycol n-propyl ether

B-3: tripropylene glycol n-butyl ether

B-4: Triethylene Glycol Methyl Ether

C-1: isobutanolamine

D-1: Butanol

As can be seen from Table 1 above, the detergent compositions of Examples 1-10 containing both alkoxy alkyl alcohols of formula (I) and alkoxy propanols of formula (II) showed overall good cleaning power in both types of dipping and spraying. Foaming was also insignificant. On the other hand, the detergent compositions of Examples 11-15, which did not contain either alkoxy alkyl alcohols of formula (I) or alkoxy propanol of formula (II), showed poor cleaning power compared to Examples 1-10 and showed reduced cleaning power in immersion type than spray type. Was bigger.

On the other hand, the rest of the components without change the cleaning composition of Comparative Example 1-5 containing tetrahydrofurfuryl alcohol conventionally used in the detergent instead of the alkoxy alkyl alcohol compound of formula (I) showed excellent cleaning power in the spray type, but in the immersion type It showed a markedly reduced cleaning power. Prior art cleaner products using tetrahydrofurfuryl alcohol as the main solvent showed good cleaning power in the spray type, as is known in the art, but showed a significantly reduced cleaning power in the immersion type. In all the comparative examples including commercially available Comparative Example 6, the height of the bubble is 2.2 cm appeared largely formed compared to the cleaning composition of the present invention showing the most 0.5 cm, bubble removal time also Comparative Examples 1-6 is 6-7 The cleaning composition of the present invention was evaluated to be low-foaming in that the foam was removed within 2 minutes while taking minutes. 2A and 2B show the results of comparing the foam heights of Example 1 and Comparative Example 6, respectively.

Also, as can be seen in FIGS. 1A and 1B, the cleaning effect of the cleaning composition of the present invention can be clearly confirmed through comparison of the flux cleaning using the cleaning composition of the present invention and before the flux cleaning.

In addition, as can be seen in Figures 3A and 3B, the surface of the substrate before and after cleaning was checked by FT-IR to determine whether the cleaning agent component remained, and the same peak was obtained before and after cleaning, indicating that no cleaning agent component remained. Could.

From this, the detergent composition containing both the alkoxy alkyl alcohol of formula (I) and the alkoxy propanol of formula (II) of the present invention is an excellent solder flux removal detergent composition which shows excellent cleaning power in both spray type and immersion type and hardly generates bubbles. You can check it.

1A and 1B are photographs before and after removal of flux using the cleaning composition of Example 1, respectively.

2A and 2B show results obtained by comparing the foam heights of Example 1 and Comparative Example 6, respectively.

3A and 3B are graphs in which peaks are identified on the surface of the substrate before and after the treatment using FT-IR in order to confirm whether the detergent component remains after the treatment of the cleaning composition, 3a is a substrate before treatment, and 3b is a treatment of Example 1 After substrate.

Claims (16)

Cleaning composition for solder flux removal comprising 20 to 60% by weight of alkoxy alkyl alcohol of formula (I) and 20 to 60% by weight of alkoxy propanol of formula (II): [Formula I] C _N H 2 _{N +1} -ORC _M H _{M -1} -OH (In the formula (I), R is an alkyl group of C ₀ ~ C ₄ , N is an integer of 1 to 4, M is an integer of 1 to 4); [Formula II] C _L H _{2L +} 1-(CH ₂ CHCH ₃ O) _K -OH (In Formula II, L is an integer of 1 to 4, K is an integer of 1 to 3). The cleaning composition according to claim 1, which is for removing lead-free solder flux. The cleaning composition according to claim 2, which is used for removing lead-free solder flux for flip chips. The alkoxy alkyl alcohol of formula I according to claim 1, wherein the alkoxy alkyl alcohol of formula I is methoxy ethanol, ethoxy ethanol, proxy ethanol, butoxy ethanol, methoxy propanol, ethoxy propanol, proxy propanol, butoxy A cleaning composition selected from the group consisting of propanol, methoxy butanol, ethoxy butanol, methoxy methyl propanol, and methoxy methyl butanol. The alkoxy propanol of formula (II) is propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl. Cleaner composition selected from the group consisting of ether, tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, and tripropylene glycol n-butyl ether. The cleaning composition according to any one of claims 1 to 3, wherein the alkoxy alkyl alcohol of formula (I) and alkoxy propanol of formula (II) are used in a ratio range of 25:75 to 75:25. The cleaning composition according to any one of claims 1 to 3, wherein the total content of the alkoxy alkyl alcohol and the alkoxy propanol is in the range of 30 to 90% by weight based on the total weight of the cleaning composition. The cleaning composition according to any one of claims 1 to 3, further comprising an amine compound and an alcohol compound. The detergent composition of claim 8, wherein the amine compound is used in a range of 5 wt% to 15 wt% based on the total weight of the detergent composition. The detergent composition of claim 8, wherein the alcohol compound is used in the range of 1 to 10 wt% based on the total weight of the detergent composition. The amine compound according to claim 8, wherein the amine compound is ethanolamine, diethanolamine, triethanolamine, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, n-propylamine, di-n- Selected from the group consisting of propylamine, tri-n-propylamine, isopropylamine, di-isopropylamine, tri-isopropylamine, n-butylamine, isobutylamine, sec-butylamine, and tert-butylamine Cleaning composition. The alcohol compound of claim 8, wherein the alcohol compound is methanol, ethanol, propanol, isopropanol, butanol, 2-butanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, methyl propanol, methyl butanol, Trifluoroethanol, allyl alcohol, 1-hexanol, 2-hexanol, 3-hexanol, 2-ethyl hexanol, 1-pentanol, 1-octanol, 1-decanol, 1-dodecanol, cyclo Cleaner composition selected from the group consisting of hexanol, cyclopentanol, ethylene glycol, propylene glycol, butylene glycol and mixtures thereof. A method for cleaning and removing residues of flux after solder, comprising using a cleaning flux composition for solder flux removal containing alkoxy alkyl alcohols of Formula I and alkoxy propanol of Formula II: [Formula I] C _N H 2 _{N +1} -ORC _M H _{M -1} -OH (In the formula (I), R is an alkyl group of C ₀ ~ C ₄ , N is an integer of 1 to 4, M is an integer of 1 to 4); [Formula II] C _L H _{2L +} 1-(CH ₂ CHCH ₃ O) _K -OH (In Formula II, L is an integer of 1 to 4, K is an integer of 1 to 3). The method of claim 13, wherein the residue of flux after lead-free solder is cleaned and removed. 15. The method of claim 14 wherein the residue of the flux after lead-free soldering of the flip chip is cleaned and removed. The alkoxy alkyl alcohol of formula (I) and the alkoxy propanol of formula (II) are contained in a ratio range of 25:75 to 75:25, and the total content of alkoxy alkyl alcohol and alkoxy propanol. The range of 30 to 90% by weight based on the total weight of the silver detergent composition.

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