JPH07503032A - Article cleaning method and cleaning composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Article cleaning method and cleaning composition The present invention relates to a method of cleaning articles and a cleaning composition for use in the method.

In the production of printed circuit boards (PCBs), flux combined with solder is applied to printed circuit boards. It is common to use a solder to promote a strong bond of the solder to the printed circuit board. flack For example, wave soldering is a method or flow soldering is a method. applicable by law. After soldering, the flux remains on the printed circuit board. the remains The residual flux needs to be removed to reduce the possibility of premature circuit failure. Ru.

Soldering is an electronic component that uses technology, for example, the flash used in the manufacture of PCBs. The flux is generally a rosin-containing flux or a synthetic water-soluble flux.

Mildly activated rosin (HMA) flux as rosin-containing flux and rosin activated (RA) fluxes, which include, for example, organic acids, Activation of rosin-containing fluxes using amines, amides or halogen-containing compounds Obtained by sexualization. Many of the activators decompose during soldering and thus Generates inorganic substances that can damage sub-components. In this way, the residue to be removed is rosin molecules. and combinations of inorganic substances.

Soldering is used in many traditionally used methods for subsequent defluxing of articles. , the residual flux had been removed using halogenated hydrocarbon solvents. but However, in recent years it has been recognized that these solvents have particularly harmful effects on the environment. It has become possible to do so. Furthermore, due to their physical properties, special requirements apply to them. required for their storage, handling and disposal. Therefore, halogenated charcoal should be used where possible. It is desirable to avoid the use of hydrohydric solvents.

EP 416.763 discloses that terpene hydrocarbons or other non-halo Discloses a composition for cleaning soiled articles, such as I'CB, containing a genified solvent. Ru. After the cleaning process, any remaining traces of solvent form an azeotrope of solvent and aqueous medium. is said to be removed azeotropically by producing Evaporated from the surface of the article. If necessary, use a low-boiling organic solvent such as a ketone or a Minerals, ethers, or alcohols are included in the cleaning composition to promote the formation of azeotropes. May be promoted. Low-boiling organic solvent, if present, 03-C4 alcohol It is preferable that

Japanese Patent No. 3-6300 discloses that, together with turpentine oil and a surfactant, Contains terpene hydrocarbons selected from IOc monoterpenes to 15C sesquiterpenes. Discloses the use of lipophilic detergents. Its composition consists of alcohol (the only one indicated) examples are c3 alcohols), ethers, ketones, esters, aromatics or or may further contain water.

U.S. Pat. No. 4,983,224 discloses that terpenes or terpenols, surface Cleaning compositions comprising an activator and an aprotic solvent, such as DMF or DMSO is disclosed.

European Patent No. 120.319 discloses a method for removing wax from electronic components. Discloses a cleaning composition, the composition comprising a halogenated hydrocarbon or a non-halogen fluorinated hydrocarbons, fluorinated alcohols containing at least two fluorine atoms, and as necessary , further contains another polar organic solvent. Hydrocarbons are, inter alia, petroleum ether It may be. Further polar organic solvents may be e.g. alcohols. stomach.

as alcohol, aliphatic alcohols having in each case not more than 7 carbon atoms; , cyclic alcohols and aromatic alcohols have been proposed.

British Patent No. 2.175.004 discloses that from metal surfaces and plastic surfaces Discloses a cleaning composition for removing dirt and grease, the composition comprising: Non-aromatic hydrocarbon water containing 5 to 97 parts by weight of aliphatic compounds and/or alicyclic compounds alkyl containing 3 to 15 parts by weight of at least one C8-C1,8 alkyl group; aromatics and, in a preferred form, 0.1-1 parts by weight of additives (such as makes the composition incompatible with water, thus facilitating its separation from water after the washing step) including. Additives include aliphatic alcohols, alkylene alcohols having 8 to 20 carbon atoms. Ether derivatives of glycols and hydroxycarbons having more than 8 carbon atoms It may be selected from rubonic acids.

British Patent No. 1.524.448 discloses that oily contaminants and fatty contaminants from the surface A cryogenic cleaner for removing substances is disclosed. Its composition consists of mineral oil distillate ( This is preferably a predominantly paraffinic or naphthenic fraction), and saturated or unsaturated aliphatic alcohols or fats containing 6 to 20 carbon atoms. Contains cyclic alcohols and/or fatty acids and sulfosuccinic acid diesters Good too.

It is said that unsaturated alcohols are preferred as alcohols.

International Patent No. 8710020-1 specifies a printed circuit board and/or a wiring board. discloses a method for cleaning rosin flux or adhesive tape residue, and this method Now, these plates are treated with a surfactant (which can emulsify the terpenes) if necessary. The combination is contacted with a composition containing a terpene.

European Patent No. 412.475 discloses a cleaning composition for cleaning PCBs. The composition contains no hydrocarbon solvents other than dibasic acid esters and terpenes. include.

As hydrocarbon solvents, solvents derived from petroleum, such as mineral spirits, Naphtha and aromatics have been proposed. The composition comprises a dibasic acid ester and To improve the miscibility of the hydrocarbon solvent, further components, e.g. It may also contain a surfactant.

EP 104.633 immerses a printed circuit board in an azeotropic liquid solvent. A method for cleaning PCBs is disclosed. Azeotropic liquids are relatively low molecular weight hydrocarbons, e.g. For example, together with nclohexane or hebutane, a low molecular weight alcohol, e.g. , C3 or C4 alcohol.

European Patent No. 302.313 discloses that an object is treated in a closed container with water and another solvent, For example, azeotropic mixtures of methylene chloride, trichloroethylene or tetrachloroethane Discloses a method for cleaning objects treated with compounds.

The present invention provides an article (i) Selected from C8 to CI5 paraffinic hydrocarbons and naphthenic hydrocarbons The total content of aromatic compounds and hydrocarbons in the potash liquid a hydrocarbon-containing liquid having an aromatics content of not more than 8% by weight, based on i) One selected from C5 to CI5 linear or branched saturated aliphatic alcohols This is a method for cleaning articles that come into contact with alcohol-containing liquids containing the above alcohols. These liquids are substantially free of rogen-containing organic compounds, and the process is When the article is contacted with a liquid mixture comprising components (i) and (ii), component (i) i) corresponds to at least 5% by volume based on the total content of hydrocarbons and alcohols; To provide a method for cleaning an article, which is characterized in that:

Advantageously, the one or more liquids contain less than 5 ppm of halogen.

The article may be contacted sequentially with a hydrocarbon-containing liquid and an alcohol-containing liquid.

However, it is preferred that the article is contacted with a liquid mixture of said liquid, said The mixture contains 75 to 95 parts by volume of 08 to C15 paraffinic hydrocarbons and naphthenic hydrocarbons. one or more hydrocarbons selected from hydrocarbons, and 5 to 25 parts by volume, preferably 8 to 25 parts by volume. 15 parts by volume of C5-C15 straight or branched chain saturated aliphatic alcohol.

The aromatics content of a liquid mixture is the combination of aromatics and hydrocarbons in the mixture. It will be appreciated that it will not exceed 8% by weight based on the total content.

Advantageously, the hydrocarbon-containing liquid is a distillate fraction obtained during distillation of petroleum.

The hydrocarbon-containing liquid has a normal concentration of 0.5 to 2 parts by volume per 1 part by volume of naphthalene. Preferably, it includes fins and isoparaffins. Aromatic compounds if present does not exceed 2% by weight based on the total weight of hydrocarbons and aromatic compounds. It is more preferable that the amount does not exceed 1% by weight. For example, hydrocarbon-containing The liquid contains less than 1% by weight of aromatic compounds based on the total weight of the liquid, and about 55 parts by volume of normal paraffin and isoparaffin and about 45 parts by volume of naphtha It may also contain ren.

The distillation boiling range of hydrocarbon-containing liquids is within the range of 150°C to 260°C at atmospheric pressure. It is preferable.

Alcohol-containing liquid (this includes an alcohol selected from 06 to C8 alcohols) (advantageously) is an aliphatic alcohol which may be linear or branched. Preferably, it contains a mixture of. The distillation boiling range of alcohol-containing liquids is at atmospheric pressure. It is preferably within the range of 150°C to 310°C.

In the cleaning method, the article is cleaned without ultrasonic agitation or preferably with ultrasonic agitation. By immersion in a liquid component or liquid mixture thereof with stirring; by spraying; by condensation by contacting the article with steam under conditions such that The hydrocarbon component and the alcohol component may be contacted in combination.

When the article is brought into continuous contact with hydrocarbon-containing liquids and alcohol-containing liquids , the article may first be contacted with any liquid. items are brought into contact The liquid or mixture is at a temperature between ambient temperature and 90°C, more preferably between 40°C and 50°C. It may also be temperature. The cleaned article is then placed in air, preferably hot air. May be dried.

If necessary, the article is contacted with a detergent solution and rinsed with water to remove the detergent solution. and then may be dried.

The detergent solution contains alkylbenzene sulfonates and alkylphenol alkoxy eg, alkylphenol ethoxylates. alkyl The alkyl group of benzene sulfonate and alkylphenol alkoxylate is , in each case aliphatic alkyl groups with 8 to 14 carbon atoms, cyclic alkyl groups Advantageously, it is a group or a cycloaliphatic alkyl group. The detergent solution can be It is a mixture of decylbenzene sulfonate and dodecylphenol ethoxylate. You can. After the article has been brought into contact with the detergent solution, residual detergent is removed from water, preferably water. is suitably removed by rinsing with deionized water.

Application of the detergent solution and subsequent rinsing removes any potential that may be present in the residual flux. Helps remove harmful inorganic substances.

Preferably, the article is an electronic component, more particularly a PCB.

The method of the present invention provides cleaning of nolded articles through the use of rosin-containing flux. Although the method can also be used with particular advantage for the synthesis of water-soluble fluxes, It may also be used to clean more soldered items.

Furthermore, the present invention (i) 75 to 95 parts by volume of distilled fraction obtained by distillation of petroleum (the said fraction is 08-CI of 92% by weight or more, preferably 99% by weight or more based on the total weight (including hydrocarbons selected from 5 paraffinic hydrocarbons and naphthenic hydrocarbons) and (ii) a C5 to C15 straight or branched saturated aliphatic alcohol. 5 to 25 parts by volume of one or more types of alcohol, said composition for cleaning articles, said composition comprising: , an article characterized in that the composition is substantially free of halogen-containing organic compounds. A cleaning composition is provided.

The method of the invention is particularly advantageous for removing flux residues after soldering. Carbonization When using hydrogen-containing liquids and alcohol-containing liquids, do not use halogenated solvents. Enables excellent removal of flux residues to be obtained. Provides beneficial cleaning effects It is thought that it will be possible. Why use a combination of polar and non-polar solvents? As a result, both polar and non-polar components of the flux residue are easily dissolved. This is because Each carbon number range specified for hydrocarbon components and alcohol components By choosing within this range, dissolution of the rosin molecules is enhanced. In addition, hydrocarbon The use of mixtures and/or mixtures of alcohols facilitates dissolution of the rosin molecules.

The solvents and solvent mixtures used according to the invention are halogen-substituted organic compounds (such as (known to have ozone-depleting properties) can be avoided. It also provides excellent cleaning performance. Moreover, the mixture has low toxicity and high toxicity. has a flash point, so it is relatively safe to use and requires no complicated handling No operation required. Additionally, it is non-corrosive to the materials commonly used in the manufacture of PCBs. Not edible.

The following examples illustrate the invention.

Example 1 Defense Standard 59-47: l-me and circuit The boards were soldered using one of the following three methods.

(a) Liquid flux Using 63/37 (tin/lead) alloy, circuit boards or combs at 1.5a+/min Soldering was carried out at 250°C with a conveyor speed of . Before soldering, clean the circuit board. Or the upper side of the comb was preheated to about 90°C. Apply flux using a brush Ta. In each case, RMA, RA, water-soluble synthetic liquid flux or no-clean ( A no clean liquid flux was used. The same no-clean flux is Can be used without the need for subsequent cleaning, at least in the case of low-grade electronic components. It is a flux that ) (b) Solder cream The cream used was a cream of 86% metal MS powder with a tin content of 62%. It was mu. Apply the cream to circuit boards or combs by manual screen printing. It was coated and reflowed by heating in a BTIJ infrared oven. each place RMA cream flux or “no-clean” synthetic water-soluble cream flux Use this.

(C) Flux cored wire The circuit board or comb is 60/40 (tin/lead) with R^ flux, melting point 3. 62℃, +6 SWG 5-core, solder by hand at 360℃ bit temperature /1 I added a note.

8 pieces of solder are printed circuit board, 8 pieces of solder are comb, isomer 06, 10 parts by volume of C7 and C8 alcohol, a C11-Cl3 paraffin compound, and It was cleaned with a cleaning composition containing 90 parts by volume of a hydrocarbon liquid consisting of naphthenic compounds.

The properties of the mixture were determined and were as follows.

Test Measurement Method Results Distillation ASTM t186 IBP 182℃ 50% 213℃ IBP and FDP represent the respective temperatures at which boiling begins and ends. PMC G stands for Pensky-Martens sealed cup. Taste.

Each solder is cleaned by cleaning the circuit board or comb with 50% of the cleaning composition at 45°C under ultrasonic agitation. Washed individually in 0ml.

Then solder the circuit board or comb in dodecylbenzene in deionized water. Detergent containing a mixture of sulfonate and dodecylphenol ethoxylate IO% by volume Rinse by immersion in solution. Then place the circuit board or comb in deionized water Rinse and dry in hot air.

Tests for residual ion contamination were performed using a given volume of 75/25 v/v isopropylene. Using a test solvent containing Patur/deionized water, the Kenko Omegameter (Ke For circuit boards or combs cleaned in nco (mg-aIlletter) I went individually. We also tested a series of unsoldered circuit boards and combs. A reference line was obtained for comparison purposes. The results are shown in Table 1. In the table, the ion contamination level The module measures the average contamination of a given number of unsoldered combs and circuit boards. This is the amount of ionic substances measured with respect to the reference line.

Table 1 Ion contamination level (μg of NaCI several years square inch flux not cleaned) If washed, if washed 4, unwashed synthetic liquid 6.6 3.2 7. No-clean synthetic ream 25.8 6.68, RA wire 42.5 3. 6 Additionally, the surface insulation resistance (SIR) of the circuit board and comb was measured. Regarding SIR test the initial insulation resistance of each circuit board or comb to 500V for 1 minute. I) Measure the voltage using C and then heat each circuit board or comb to 40℃. , 90% relative humidity (R)l) for 96 hours. Then, remove the SIR. Measure again using 500V DC under humidity conditions (90% relative humidity, 40°C). Established. The results of the SIR test are shown in Table 2.

The results showed that residual solder was effectively cleaned of flux, and the level of ionic contamination was reduced. Equivalent to 14 μg NaCl/in2 (2,2 μg/c+n’) MIL Demonstrate that the requirements are well below P-28809A requirements. Also, the result is After the cleaning process, the resistance of the circuit board and comb is approximately the same as the resistance of the uncleaned circuit board. Indicates the same or lower. In this way, the cleaning process Does not have any harmful effects. In many cases, the SIR is improved after cleaning. Also, wash The cleaned circuit board was exposed to a 90% R8, 40°C atmosphere for 96 hours before SI Works well in the R test.

Example 2 5 parts by volume of isomeric 06 and C7 alcohols and Cl0-Cl3 paraffins and naphs A cleaning mixture containing 95 parts by volume of ten was prepared.

Physical data regarding the mixture was measured and was as follows.

Test Measurement Method Results Distillation ASTM D86 IBP　165.0℃ 50% 192.0℃ FI3P　2]2.　O℃ Flash point, PMCCASTM C9360, density at 0°C and 15°C ASTM C40520, 7796g/cc aniline point ASTM C61165, 5°C EVOLT Chromaticity ASTiJ Cl56 +30 Efficiency of rosin removal from circuit board For evaluation, six PCBs coated with activated flux were cleaned and each The PCB was heated at 45 °C in 100 ml of the cleaning mixture for 5 minutes with ultrasonic agitation. were washed individually.

After cleaning, remove the specimen, dry it, and remove any residual rosin from the circuit board. Extracted with lopyl alcohol (IPA) +00011.

The rosin content of IPA was measured spectrophotometrically at a wavelength of 242 nm.

For comparison purposes, a halide containing 3 parts by volume of CFC-11393 and 7 parts by volume of methanol was used. Prepare rogens cleaning liquid and clean 6 PCBs coated with activated flux for 5 minutes. individually by condensed vapor (boiling point 48°C) of a halogen liquid in a closed container for a period of time. Washed.

After cleaning, the specimens were treated as for hydrocarbon/alcohol cleaning. Conclusion The results are shown in Table 3, which shows that using the halocarbon solvent system only 61% of the average compared to the level cleaning efficiency obtained using hydrocarbon/alcohol mixtures. It is shown that an average cleaning efficiency (ie, rosin removal rate (%)) of 7% is obtained.

Table 3 0jin removal rate (%) 123456 Hydrocarbons/90.1 86.7 88.8 85.4 85.7 87.1 Ha Rocarbon/61.3 61.8 65.7 54.2 63.5 60.9 alcohol blend international research report 11. fi-A1. -9. Pc■/EP92103o1・Continuation of front page (51) Int, C1,' Identification code Office serial number HOIL 23150 Z 8617-4MH05K 3/26 7511-4E //CC11D 7/60 7:24 7:26) I

Claims (12)

[Claims] 1. goods (i) selected from C8-C15 paraffinic hydrocarbons and naphthenic hydrocarbons A liquid containing one or more hydrocarbons, and the aromatic compounds and hydrocarbons of the liquid A liquid having an aromatic compound content of not more than 8% by weight based on the total content of elements, (i i) One selected from C5 to C15 linear or branched saturated aliphatic alcohols Liquids containing more than A method for cleaning articles that are brought into contact with halogen-containing organic compounds, the method comprising: and the method is capable of converting the article into a liquid mixture containing components (i) and (ii). When contacted with the compound, component (ii) increases the total content of hydrocarbons and alcohols. A method for cleaning articles, characterized in that it corresponds to at least 5% by volume as a standard. 2. These liquids are (i) 75 to 95 parts by volume of C8 to C15 paraffinic hydrocarbons and naphthenic carbons; one or more hydrocarbons selected from hydrocarbons; (ii) 5 to 25 parts by volume of C5 to C15 straight or branched chain saturated aliphatic alcohol; Claims are in the form of a liquid mixture containing one or more alcohols selected from The method described in box 1. 3. Claim 2, wherein the mixture contains 8 to 15 parts by volume of alcohol component. How to put it on. 4. Claims 1 to 3, wherein the alcohol is selected from C6 to C8 alcohols. The method described in any one of paragraphs. 5. A distillation fraction obtained in the distillation of petroleum as a hydrocarbon-containing liquid, comprising: The distillation distillate has an aromatic component content of 8% by weight or less based on the total weight of the distillation distillate. 5. The method according to any one of claims 1 to 4, using minutes. 6. 2% hydrocarbon-containing liquid based on the total amount of aromatic and hydrocarbon components Claim 1 containing not more than 1% aromatic components, preferably not more than 1%. - The method according to any one of clauses 5 to 5. 7. Claim No. 1 in which the article is immersed in a liquid or mixture and subjected to ultrasonic agitation. The method according to any one of items 1 to 6. 8. Claim 1: After contacting the liquid or mixture, the article contacts a detergent solution. 7. The method according to any one of paragraphs 7 to 8. 9. The detergent solution contains alkylbenzene sulfonates and alkylphenol alkoxy 9. The method according to claim 8, containing sylate. 10. The person according to any one of claims 1 to 9, wherein the article is a PCB. Law. 11. A composition for cleaning articles, the composition comprising: (i) obtained in the distillation of petroleum; A distillation fraction containing C8 to C15 paraffin based on the total weight of the distillation fraction. Contains 92% by weight or more of hydrocarbons selected from hydrocarbons and naphthenic hydrocarbons. 75 to 90 parts by volume of the distilled fraction, and (ii) C5 to C15 straight or branched chain 5 to 25 parts by volume of one or more types of alcohol selected from saturated aliphatic alcohols; and the mixture is substantially free of halogen-containing organic compounds. Composition for cleaning items. 12. Use of a mixture for cleaning articles, the mixture comprising (i) C8- One or more types of carbon selected from C15 paraffinic hydrocarbons and naphthenic hydrocarbons 75 to 95 parts by volume of hydrogen hydride, and (ii) selected from C5 to C15 linear or branched saturated aliphatic alcohols; 5 to 25 parts by volume of one or more types of alcohol, and the content of the aromatic component in the mixture is equal to that of the aromatic component and the hydrocarbon component. 8% by weight or less based on the total amount, and the mixture contains a halogen-containing organic compound. Use of the above mixture substantially free of.