JP3499809B2 - Cleaning remover and cleaning method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is produced on a terminal surface or a solder surface by removing a solder flux residue adhered to a component surface after soldering various electronic components such as a printed wiring board and an IC, and by heat treating the electronic component. The present invention relates to a cleaning remover and a cleaning method used for removing an oxide film such as an oxide film on a metal surface.

[0002]

2. Description of the Related Art Generally, in the soldering of electronic parts, rosin, active rosin, stearic acid, oleic acid, aniline hydrochloride, as a solder flux for cleaning the joint and preventing oxidation of the joint surface, Organic fluxes such as urea and ethylenediamine are widely used. However, these solder fluxes remain on the surface of the component after soldering as a form as it is or as a modified product generated by carbonization or decomposition by heat, which may cause circuit disconnection or conductivity failure, etc. It is important to remove the solder flux residue containing the substance. In addition, organic contaminants such as fats and oils are often attached to the surfaces of electronic components and mechanical components, and it is necessary to wash and remove the contaminants depending on the application.

On the other hand, depending on the electronic component, an oxide film may be formed on the surface of the terminal or the surface of the solder, and when soldering to this electronic component, there is a risk of defective soldering, so this oxide film is removed. It is desirable to do.

Conventionally, fluorine-based solvents and chlorine-based solvents have been generally used for cleaning and removing solder flux residues and organic stains, but in recent years, they can be used because they cause ozone layer depletion and toxicity. It's gone. Therefore, as a new cleaning / removing agent that substitutes for these, for example, in Japanese Patent Laid-Open No. 7-3294, an alcohol solvent having 3 or more carbon atoms, a hydrocarbon solvent, and a fourth basic substance are used.
A cleaning composition consisting of three components with a primary ammonium base has been proposed.

[0005]

However, although the cleaning composition of the above-mentioned proposal has some cleaning and removing effect on solder flux residues and organic stains, it cannot be said to be sufficient, and the surface of terminals of electronic parts is not satisfactory. There is a problem in that it has almost no effect of removing the oxide film formed on the solder surface or the solder surface, and there is a handling risk in using a lower alcohol solvent having a low flash point such as isopropyl alcohol. In particular, the above oxide film is originally said to be difficult to remove, and cleaning with a fluorine-based solvent or a chlorine-based solvent is not effective. Further, in the case of cleaning with an acid or an alkali, even if the oxide film can be removed, the material will be corroded, so that it cannot be used at all when electronic parts are targeted.

In view of the above-mentioned circumstances, the present invention is directed to the removal of solder flux residue and organic contaminants such as oils and fats adhered to the surfaces of various electronic parts and mechanical parts after soldering, and the surface of terminals of electronic parts. An object of the present invention is to provide a cleaning remover and a cleaning method capable of removing an oxide film on a metal surface such as an oxide film formed on a solder surface or a solder surface.

[0007]

In order to achieve the above object, the cleaning and removing agent for electronic parts according to claim 1 of the present invention comprises:
a) 3-methoxy-3-methyl-1-butanol,
b) Water-soluble thioglycolate is included as an essential component.

The invention of claim 2 is the same as that of claim 1.
In the cleaning / removing agent for electronic parts, the weight ratio of the component a / component b is in the range of 27/73 to 87/13.

The invention of claim 3 is the same as that of claim 1 or 2.
In the cleaning / removing agent for electronic parts , c) polyoxyethylene alkyl ether is contained together with the above-mentioned components a and b in a proportion of 0.7 to 20% by weight in the total amount of the cleaning / removing agent.

According to a fourth aspect of the present invention, in the cleaning / removing agent for electronic parts according to any one of the first to third aspects, the water-soluble citrate d) is contained in the total amount of the cleaning / removing agent together with the components a and b. It is configured to be contained in a proportion of 0.7 to 10% by weight.

According to a fifth aspect of the present invention, in the cleaning / removing agent for electronic parts according to any one of the first to fourth aspects, together with the a component and the b component, e) benzotriazole, benzothiazole, 2-mercaptobenzothiazole, At least one corrosion inhibitor component selected from the group consisting of 2-mercaptobenzimidazole and thiourea is contained in an amount of 0.7 to 10% by weight based on the total amount of the cleaning and removing agent.

According to a sixth aspect of the present invention, in the cleaning / removing agent for electronic parts according to any of the first to fifth aspects, the corrosion inhibitor component of the e component according to the fifth aspect is used together with the a component and the b component. , F) Alkyldi (aminoethyl) glycine hydrochloride or / and sodium alkyldi (aminoethyl) glycine are respectively 0.7 to 10 in the total amount of the washing and removing agent.
The composition is such that it is contained in a proportion that accounts for weight%.

According to a seventh aspect of the present invention, in the cleaning / removing agent for electronic parts according to any one of the first to sixth aspects, PH is 5.1.
The range is from 8.9 to 8.9.

Furthermore, a cleaning method of an electronic component according to an eighth aspect of the present invention has the same purpose as described above, wherein the cleaning using the electronic component cleaning / removing agent according to any one of the first to seventh aspects is performed. It is characterized by removing the solder flux and its modified products remaining on the surface of the component after soldering.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the cleaning / removing agent for electronic parts according to the present invention comprises: a) 3-methoxy-3-methyl.
1-Butanol and b) a water-soluble thioglycolate are contained as essential components, and when an object to be cleaned is immersed in the cleaning / removing agent and subjected to cleaning treatment such as ultrasonic cleaning, electronic parts In addition to the solder flux residue (including modified products generated by carbonization and decomposition due to heat, etc.) and organic stains such as fats and oils that have adhered to the surface after soldering,
It has an excellent feature that the oxide film on the metal surface can be dissolved and removed by the cooperation of both components a and b. Also, a,
Since both components are water-soluble, the washing remover in which the dirt and the oxide film are dissolved can be easily removed from the surface of the object to be washed by washing with water, and the flash point is high. Both components b have low toxicity, so they are also safe during handling.

The a-component 3-methoxy-3-methyl-1-butanol is a compound which is liquid at room temperature, and exhibits a dissolving power for rosin, higher fatty acids, fats and oils which are often used in solder flux. It functions as a solvent.

The water-soluble thioglycolate salt of component b is not particularly limited, and examples thereof include ammonium thioglycolate, sodium thioglycolate, potassium thioglycolate, thioglycolic acid monoethanolamine, and thioglycolic acid diethanolamine. , Thioglycolic acid triethanolamine and the like are preferable. Then, these thioglycolates may be mixed with 3-methoxy-3-methyl-1-butanol as the component a as an aqueous solution having a concentration of about 10 to 50%.

In the cleaning / removing agent, the above-mentioned a component and b
The mixing ratio with the components is 27 / in terms of the weight ratio of a component / b component.
The range of 73 to 87/13 is suitable, and if the component a is too small, the dissolving power for organic contaminants such as solder flux residue will be insufficient, and if the component b is too small, the oxide film on the metal surface will be formed. Removability deteriorates.

In this cleaning / removing agent, the above a, b
By adding polyoxyethylene alkyl ether as the component c together with the component, the cleaning property can be improved. That is, the component c is a nonionic surfactant, which reduces the surface tension of the cleaning / removing agent to improve the wetting of the cleaning / removing agent on the surface of the object to be cleaned, and the cleaning / removal of organic stains and oxide films. It serves to enhance the permeability of the agent and the detachability of the dissolved component from the surface of the object to be cleaned, thereby promoting the dissolution thereof.

The polyoxyethylene alkyl ether of component c is not particularly limited, but a secondary alcohol to which 7 to 15 mol of ethylene oxide is added is recommended as the one showing the best cleaning effect. To be done. However, the content of the component c is preferably in the range of 0.1 to 10% by weight in the total amount of the cleaning and removing agent. If it is too small, the sufficient effect cannot be obtained. No further effect can be obtained.

Further, in this cleaning / removing agent, a, b
It is recommended to incorporate a water-soluble citrate salt as component d with the components. This water-soluble citrate improves the wettability of the cleaning / removing agent to the surface of the non-cleaning material as well as the above-mentioned component c, and enhances the permeability of the cleaning / removing agent to the organic dirt and oxide film, and dissolves these. In addition to the function of facilitating the cleaning removal agent, the cleaning removal agent exerts a function as a PH buffering agent that suppresses a temporal change in PH, and has an advantage of facilitating the storage and management of the cleaning removal agent.

Examples of the water-soluble citrate salt of the component d include ammonium citrate, sodium citrate, potassium citrate, monoethanolamine citrate, diethanolamine citrate, triethanolamine citrate and the like. However, the content of the c component is preferably in a range of 0.7 to 10% by weight in the total amount of the cleaning and removing agent. If it is too small, a sufficient effect cannot be obtained. In addition to not contributing to the action, the solubility of organic contaminants such as solder flux residue is rather reduced.

Further, as the cleaning / removing agent, in order to more reliably suppress oxidative corrosion with respect to metals, a group of benzotriazole, benzothiazole, 2-mercaptobenzothiazole, 2-mercaptobenzimidazole and thiourea as an e component. It is recommended to incorporate at least one corrosion inhibitor component selected from the above. However, among these e components, benzotriazole is the most preferable because it is excellent in discoloration prevention and corrosion inhibition effect on non-ferrous metals such as copper, brass and solder as compared with other corrosion inhibitor components. is there. The amount of such a corrosion inhibitor component of the component e is preferably in the range of 0.7 to 10% by weight in the total amount of the cleaning and removing agent, and if it is too small, a sufficient effect cannot be obtained.
On the contrary, if the amount is too large, the above effect is not obtained and the cost of the cleaning and removing agent is increased.

Furthermore, in this cleaning and removing agent,
Along with the a and b components, the corrosion inhibitor of the e component, and alkyldi (aminoethyl) glycine hydrochloride as the f component or /
And sodium alkyldi (aminoethyl) glycine are desirable. That is, these e component and f component are used as an oxidative corrosion inhibitor that enhances the ability of the cleaning and removing agent to remove an oxide film on the metal surface and suppresses reoxidation of the metal surface after removing the oxide film by using both of them. Work together. .

The amounts of the components e and f are preferably in the ranges of 0.7 to 10% by weight based on the total amount of the cleaning and removing agent. If the amounts are too small, the sufficient effect cannot be obtained. However, there is no further effect and the cost of the cleaning and removing agent is increased.

Alkyldi (aminoethyl) glycine hydrochloride as the component f has the following general formula: [RNH. (C ₂ H ₄ NH) ₂ CH ₂ COOH] .HC
It is represented by l 1. Further, sodium alkyldi (aminoethyl) glycine is represented by the following general formula: RNH. (C ₂ H ₄ NH) ₂ CH ₂ COONa. And as said both compounds, the thing whose carbon number of an alkyl group (R) is mainly about 12-14 is generally used.

Since such a cleaning / removing agent has both the dissolving / removing property with respect to the organic flux such as the solder flux residue and the oil / fat as described above, and the dissolving / removing property with respect to the oxide film on the metal surface, after the soldering, At the same time as removing the organic residues such as flux residue and fats and oils that have adhered to the surface of
It is also possible to remove oxide films formed on the surfaces of terminals and solders of electronic parts .

The washing operation by the washing removal agents, electronic components performing the soldering using a solder flux organic
It is only necessary to immerse the
By adopting ultrasonic cleaning etc. in this immersion,
Improves removability of organic stains and oxide film. Also,
The pH of the cleaning / removing agent liquid is preferably set in the range of 5.1 to 8.9. That is, when the oxide film on the metal surface is removed by using one having the above PH range, the regeneration of the oxide film on the metal surface after the removal can be effectively prevented.
It has been found that the effect of suppressing the regeneration of the oxide film is reduced when the oxide film is removed by using a substance having a pH value outside the above range. However, this PH may be set empirically by adjusting the type and the quantitative relationship of the blending components in each cleaning and removing agent.

[0029]

EXAMPLES The present invention will be specifically described below with reference to examples.

Production Example 1 3-methoxy-3-methyl-1-butanol as a component, ammonium thioglycolate as b component, polyoxyethylene alkyl ether as c component (7 to 15 mol of ethylene oxide in secondary alcohol) Added, alkyl group having 12 carbon atoms, ammonium citrate as d component, benzotriazole as e component,
Alkyldi (aminoethyl) glycine hydrochloride (having 12 to 14 carbon atoms in the alkyl group) is used as the component f,
The compounding ratios (parts by weight) shown in Table 1 below were put into a stainless steel tank, stirred and mixed, and then filtered and taken out to obtain No. 1 to No. 21 cleaning and removing agents. Although ammonium thioglycolate as the component b was blended as a 30% aqueous solution, the numerical values in Table 1 are parts by weight of ammonium thioglycolate alone excluding water. The pH of each of these cleaning and removing agents was in the range of 5.1 to 8.9.

Production Example 2 In No22, sodium thioglycolate (blended as a 30% aqueous solution) was used as the b component, in No23, diethanolamine thioglycolate was used as the b component, and in No24.
Then, triethanolamine citrate as the c component, N
In o25, sodium alkyldi (aminoethyl) glycine (having 12 carbon atoms in the alkyl group) was used as the f component, and the other components used were the same as in Production Example 1, and Table 2 below was used.
No. 22 to No. 25 cleaning / removing agents were obtained in the same manner as in Production Example 1 with the described mixing ratio (parts by weight). The pH of each of these cleaning and removing agents was in the range of 5.1 to 8.9.

Cleaning and removing agent No. obtained in Production Examples 1 and 2
For No. 1 to No. 25, the removability of the flux residue and the removability of the oxide film on the metal surface were tested when used for cleaning with an ultrasonic cleaner. The results are shown in Tables 1 and 2 below. The test methods and evaluations for each item are as follows.

[Removability of Flux Residue] A rosin flux was applied to the surface of a copper plate (20 mm × 70 mm × 1 mm) and soldered (Sn60%, Pb40).
%) Attached and left for about 24 hours in air 2
It heated at 00 degreeC for 30 minutes, and made this the to-be-cleaned object. This object to be cleaned is ultrasonically cleaned in the same manner as in the case of using the cleaning / removing agent of Production Examples 1 and 2, followed by rinsing with pure water and isopropyl alcohol, dehydration, drying, and elution of flux residues, before and after the removal test. The amount of flux residue was obtained from the difference in mass and was evaluated in the following three stages. ⊙: No solder flux residue △: Slight solder flux residue ×: Remarkable solder flux residue

[Removability of Oxide Film] Regarding the copper plate before the heat treatment after soldering and the copper plate after the cleaning treatment in which the flux residue is eluted through the above-mentioned ultrasonic cleaning, the oxide film on the surface (copper and solder) Were compared quantitatively by Auger electron spectroscopy. In addition, brass plates and rolled steel plates should be heated at 200 ° C for 30 hours before heat treatment and in air.
The oxide film after the heat treatment for 1 minute was similarly quantitatively analyzed and compared. The results were evaluated according to the following three grades. ⊙… Oxidized state equivalent to that before heat treatment (oxide film disappears due to heat treatment). B: Oxidation is slightly advanced from before the heat treatment. X: Oxidation is significantly progressing before the heat treatment.

[0035]

[Table 1]

[0036]

[Table 2]

From the results shown in Table 1, it is clear that the cleaning and removing agent containing the component a and the component b exhibits the ability to dissolve and remove the flux residue and the oxide film. In particular, cleaning in which the weight ratio of a component / b component is in the range of 27/73 to 87/13, and c, d, e, and f components are each blended in an amount of 0.8% by weight or more based on the total amount of the cleaning and removing agent. Remover (No 7, 1
It can be seen that the flux residue and the oxide film can be completely removed in Nos. 0, 11, 14 to 17). On the other hand, with the cleaning remover containing the b component but not the a component (No. 1 to 3), the removability of the flux residue and the oxide film cannot be obtained,
On the contrary, a cleaning remover containing the component a and not the component b (No2
Even in 1), it is clear that the oxide film cannot be removed. On the other hand, from the results of Table 2, it is understood that sufficient flux residue and oxide film removability can be obtained even if the types of the b, c, and f components are different.

[0038]

According to the invention of claim 1 according to the present invention, as wash <br/> Kiyoshi removers for electronic parts, it is removed simultaneously with the oxide film of solder flux residue produced on the terminal surface and the solder surface of the electronic component It is also possible to provide the above-mentioned product, which is excellent in handling safety.

According to the second and third aspects of the present invention, there is provided a cleaning / removing agent having both excellent removability of organic stains such as the solder flux residue and oil and fat and removability of an oxide film.

According to the invention of claim 4, in addition to the excellent removability of the organic contaminants such as the solder flux residue and the oil and fat and the removability of the oxide film, the stability is high and the storage and management are easy. Cleaning remover is provided.

According to the fifth to seventh aspects of the present invention, the above-mentioned solder flux residue and organic stains such as oil and fat and the oxide film can be removed, and re-oxidation of the metal surface of the object to be cleaned after the cleaning treatment occurs. A cleaning remover that can be made difficult is provided.

According to the electronic component cleaning method of the eighth aspect of the present invention, organic contaminants such as solder flux residues and oils and fats and the oxide film on the metal surface can be efficiently and reliably removed.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Manabu Numata 1-12-14 Yokoe, Ibaraki-shi, Osaka Clean Chemicals Co., Ltd. Technical Department Development Section (72) Inventor Junji Sugano 3-chome, Saito, Joto-ku, Osaka-shi, Osaka No. 19 Aiken Co., Ltd. (56) Reference JP-A-7-305097 (JP, A) JP-A-7-266028 (JP, A) JP-A-6-346094 (JP, A) JP-A-9- 194892 (JP, A) JP-A-8-113797 (JP, A) JP-A-10-102091 (JP, A) JP-A-59-185786 (JP, A) JP-A-11-124599 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C11D 7/50 C11D 7/26 C11D 7/32 C11D 7/34 CAPLUS (STN) REGISTRY (STN)

Claims (8)

(57) [Claims] 1. A cleaning / removing agent for electronic parts , which contains a) 3-methoxy-3-methyl-1-butanol and b) a water-soluble thioglycolate salt as essential components. 2. The weight ratio of the component a / component b is 27 /
The electronic component according to claim 1, which is in a range of 73 to 87/13.
Use cleaning removal agent. 3. The c) polyoxyethylene alkyl ether is contained together with the a component and the b component in a proportion of 0.7 to 20% by weight in the total amount of the cleaning and removing agent. Cleaning and removing agent for electronic parts . 4. The component (a) and the component (b) together with the water-soluble citrate (d) in an amount of 0.7 to 10% by weight based on the total amount of the cleaning and removing agent.
The cleaning / removing agent for electronic parts according to any one of claims 1 to 3, wherein the cleaning / removing agent is for electronic components . 5. Along with the components a and b, e) benzotriazole, benzothiazole, 2-mercaptobenzothiazole, 2-mercaptobenzimidazole,
Electrodeposition according to claim 1, the corrosion inhibitor component of at least one is contained in a ratio which accounts for 0.7 to 10 wt% in the cleaning removing agent total amount selected from the group of thiourea
Cleaning remover for child parts . 6. The corrosion inhibitor component of component e according to claim 5, and f) alkyldi (aminoethyl) glycine hydrochloride or / and sodium alkyldi (aminoethyl) glycine together with component a and component b. The cleaning remover for electronic parts according to any one of claims 1 to 5, wherein the cleaning remover is contained in a proportion of 0.7 to 10% by weight based on the total amount of the cleaning remover. 7. The cleaning / removing agent for electronic parts according to claim 1, wherein the pH is in the range of 5.1 to 8.9. 8. The battery according to any one of claims 1 to 7.
A method for cleaning electronic parts, characterized in that an oxide film on a metal surface is removed by cleaning with a cleaning remover for child parts .