JPH0342002A - Method for washing and dehydrating article - Google Patents

Abstract

PURPOSE:To remove contaminants present on the surface of an article by successively treating the article with a detergent and a perfectly fluorinated compd. CONSTITUTION:An article is treated with at least one kind of detergent selected among alcohols, chlorine-contg. org. solvents, petroleum solvents and water soluble solvents each contg. a surfactant. The article is then treated with at least one of perfectly fluorinated compds. represented by formulae I. The removal of contaminants present on the surface of the article and dehydration easily and efficiently are carried out.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is directed to the prevention of moisture, oil, and flux present on the surfaces of articles such as electronic parts, glasses, lenses, plated products, optical disks, and metal and non-metal products. The present invention relates to a method for washing and draining articles that can easily and completely remove various other inorganic and organic contaminants (hereinafter collectively referred to as contaminants) using simple equipment and operations.

(Prior art) When removing contaminants from the surfaces of electronic components such as liquid crystals, semiconductor wafers, optical disks, plated products, glass, lenses, and metal and non-metal products, many types of contaminants are removed. However, in the case of water cleaning, it is common to use an appropriate cleaning agent for each removal process, and then perform a drying process to remove the moisture adhering to the surface of the item by some means. be.

That is, (1) alcohols such as isopropyl alcohol, ethyl alcohol, methyl alcohol, etc.;
(2) Chlorinated organic solvents such as 1,1.1-1-lichloroethane, methylene chloride, trichlorethylene, perchlorethylene, etc., (3) Fluorinated organic solvents such as trichlorotrifluoroethane (Freon R-113) solvents, (4) petroleum solvents such as toluene, xylene, benzene, etc., or (5) interfaces such as Panrise (trade name, Denban Kagaku Kogyo Co., Ltd.), Captain Clean (trade name, Adeka Argus Chemical Co., Ltd.) Cleaning agents such as water-soluble solvents containing activators, either alone or
R-113 and alcohol are used in an appropriate mixture, and the article to be cleaned is immersed in a bath containing the heated cleaning agent, and then a physical device such as ultrasonic wave or shaking is applied. This applies vibration to dissolve and remove contaminants during cleaning. However, in the case of washing with water, drying methods to remove pure water from the surface of items include methods that evaporate water by heating or reduced pressure, and physical methods that utilize compressive force, centrifugal force, etc. However, there is also a method that takes advantage of the difference in specific gravity of liquids and the difference in vaporization rate, and this method uses (a) chlorinated organic solvents and (b) alcohols as described above. Also known are methods such as (c) a cleaning agent in which a surfactant is added to Freon R-113, and (d) an azeotropic method in which an alcohol such as ethyl alcohol is added to Freon R-113. .

(Problem to be solved by the invention) However, as a cleaning agent, the alcohols in (1) have the problem of being flammable and dangerous;
The chlorinated organic solvents listed in (3) have the problem of toxicity and are subject to extremely strict conditions regarding restrictions on use, discharge, storage, etc.;
Although it is an extremely effective cleaning agent, the serious problem of ozone layer depletion has recently been pointed out, and there is a problem that its use will be banned worldwide in the near future. There is a problem of flammability, and the water-soluble solvent containing a surfactant (5) has a problem that the surfactant is extremely difficult to remove.

When these conventionally used solvents are used as cleaning agents, not only does cleaning take time, but degreasing and defluxing are insufficient. However, there is a problem in that the entire amount of cleaning liquid must be replaced from time to time. In addition, it is necessary to treat contaminated matter with purified water after washing, and even in the drying process to remove this adhered pure water, in the method (a) using a chlorinated organic solvent, if a drying process using paper washing is used, There are problems such as adsorption of water-containing substances in the outside air atmosphere due to the temperature difference with the outside air atmosphere, as well as toxicity and other problems as mentioned above. Because it has an endothermic reaction even when there is no difference from the outside air atmosphere, it is recognized that water-containing substances in the outside air atmosphere are adsorbed, and since alcohols have the effect of entraining water,
During drying, the alcohol evaporates first, leaving behind water, and there is also the problem of flammability and other dangers as mentioned above. The problem is that it is not often used for precision cleaning and drying because it is adsorbed onto the surface of the article, and can only be used in fields where residual surfactant is not a problem.
In method (d), when the item is immersed in this cleaning agent, ethyl alcohol acts on the item, and the adhering water is peeled off from the item along with the contaminants and floats to the surface of the liquid, allowing for good water removal. Although it is not visible to the naked eye, products that have been dried have fluorocarbons and ethyl alcohol adsorbed on their surfaces, and depending on the purpose, it may be necessary to treat them with hot air at several tens of degrees Celsius to remove them. There are problems in that the working environment must be strictly maintained, the equipment is complicated, and special management and knowledge are required. With this ban, there is a demand for alternative and effective cleaning and draining means.

The present invention aims to solve the above problems while using conventional cleaning agents, and to provide a means for easily and efficiently removing contaminants present on the surface of articles with a simple device. It is something.

(Means for Solving the Problems) As a result of repeated research in order to solve the above problems and achieve the above objects, the present inventors found that after processing with a conventional cleaning solution,
The present invention was made based on the discovery that the object can be achieved by treatment with a fully fluorinated compound.

That is, the present invention provides alcohols, chlorinated organic solvents,
After treatment with at least one cleaning agent selected from the group consisting of petroleum solvents and water-soluble solvents including surfactants, the structural formula: CF3 CF3-[(0-CF-CF2)N-( 0-CF2
)M ]-0-CF3 This is a method for washing and draining articles, which is treated using at least one fully fluorinated compound selected from the group consisting of fully fluorinated compounds represented by CF3.

Examples of alcohols used in the present invention include isopropyl alcohol, ethyl alcohol, and methyl alcohol. Examples of chlorinated organic solvents include 1,1,1-trichloroethane, methyl chloride, trichloroethylene, and Examples of petroleum-based solvents include toluene, xylene, and benzene. Examples of water-soluble compounds containing surfactants include Panrise (trade name) and Captain Clean (trade name). These may be those conventionally used for washing and draining articles.

Next, as a fully fluorinated compound, for example, (C4
(C4F9)3N, metal material produced by an electrolytic fluorination method in which a hydrocarbon compound such as H9)3N, CyHtsCOOCH3, etc. is dissolved in anhydrous hydrofluoric acid, reacted under certain conditions in an electrolytic cell, and then purified. , fully fluorinated CF3 of perfluoropolyether CF3-[(0-CF-CF2)N-(0-CF
2) Compounds such as M]-0-CF3 are reacted with a cobalt fluoride as a catalyst, and these fully fluorinated compounds are produced by Fluorinert (trade name, Sumitomo 3M).
, Galden (product name, Nippon Montageson Co., Ltd.), Frutic (product name, ISC), Affluid (product name, Asahi Glass Co., Ltd.), FTOP (product name, Shin-Akita Chemical Co., Ltd.), Bellfloat (product name, Tokuyama Soda) It is commercially available under product names such as Efreed (trade name, Kanto Denka Co., Ltd.), and both are completely fluorinated inert liquids that do not contain hydrogen or chlorine. Insulating properties, low surface tension, low viscosity, excellent permeability, high specific gravity, good thermal conductivity, does not dissolve in various solvents regardless of temperature, does not dissolve in water or oil, and can be used with metals, plastics, rubber, etc. It is a compound that has the characteristics of not soaking, non-flammable, and non-toxic.

In the method of the present invention using these cleaning agents, for example, (A) the conventional cleaning agent layer is formed on the liquid surface of the fully fluorinated compound in the tank, and first, the conventional cleaning agent layer is covered with The article to be treated is treated by immersion and then treated by immersion in a fully fluorinated compound and subjected to physical vibration to completely remove the treated article after overflowing the conventional cleaning agent layer that has dissolved contaminants. Method for pulling from a fluorinated compound, (B)
The article to be treated is treated by spraying the conventional cleaning agent above the liquid level of a tank containing a fully fluorinated compound, and then immersed in the fully fluorinated compound to apply physical vibration. (C) a method in which the conventional cleaning agent layer in which contaminants have been dissolved by spraying is overflowed and removed, and then the treated article is pulled up and treated; (C)
The conventional cleaning agent is placed in the first tank, and a fully fluorinated compound is placed in the second tank, and the article to be treated is first immersed in the tank (2) for treatment. Preferred methods include a method in which the material is pulled up, immersed in a second tank, and subjected to physical vibration.

In the first stage of the present invention, the treatment with a conventional cleaning agent may be carried out under conventional conditions, and the second stage treatment with a fully fluorinated compound is performed at a temperature below the boiling point of the fully fluorinated compound used. The treatment time may vary depending on the treatment temperature, the shape and size of the article, etc., but may be about 20 to 60 seconds.The physical vibration in the fully fluorinated compound treatment may be However, in the present invention, which is not necessarily required, after draining or cleaning with such a conventional cleaning agent, draining or cleaning with a fully fluorinated compound is further performed. Therefore, treatment with conventional cleaning agents is performed by a mechanism as previously described, but cleaning and draining cannot be performed completely with this treatment alone. In addition, in the next treatment with fully fluorinated metal products, when used as a cleaning agent to remove contaminants other than mercury, it is difficult to say with certainty, but the contaminants will be separated from the surface of the article, and the contaminants in the article will be removed. It is thought that it penetrates well into pores and areas with fine workmanship, promoting the action of expelling contaminants that exist within them.
Even when draining, the water adhering to the item is subject to buoyancy due to the large difference in specific gravity, and the item is covered with a fully fluorinated compound.
It is thought that the remaining moisture further weakens its adhesion, floats to the surface, and is completely expelled. Contaminants, including expelled water, are those that float to the surface without being dissolved in the fully fluorinated compound, and are removed from the system by overflowing, for example. The fully fluorinated compounds present in the separated liquid can be easily recovered and reused, and it is sufficient to replenish the reduced amount that occurs in very small amounts. is completely removed by evaporation and leaves no stains on the article, such as contaminants, cleaning agents, fully fluorinated compounds, etc. The fully fluorinated compounds in this process can be used in combinations of two or more. However, only one type can produce sufficient effects.

(Example) Next, examples of the present invention will be described.

Example 1 As a fully fluorinated compound, C'3CF3-[(0-CF-CF2)N-(0-CF2)
M]-0-CF3 is placed in a tank, and 1,
1. Use a cleaning tank filled with 1-trichloroethane to a thickness of 3 mm (both liquids are completely separated into two layers due to the difference in specific gravity) for machining work that has cutting oil attached. First, the metal parts for the machine with the size of 250x150x5 are 1
, 1. Immerse in the 1-trichloroethane layer and treat for 30 seconds to dissolve and clean the cutting oil, and then immerse the metal parts directly in the fully fluorinated compound liquid in the lower layer, 3
Washing was performed for 0 seconds. By this process, the cutting oil that could not be removed by the previous process is separated from the metal parts, floats in the liquid without being dissolved, enters the 1.1.1-trichloroethane, and is dissolved.

During these cleaning treatments, ultrasonic vibrations were applied at room temperature. Thereafter, 1,1,1-trichloroethane in which the cutting oil had been dissolved was removed by overflowing, and the metal parts were pulled up.

As a result, not only was there no cutting oil adhering to the metal parts, but no stains from either of the cleaning agents were observed at all.

Example 2 The same fully fluorinated compound as in Example 1 was placed in a tank, ethyl alcohol was poured on the liquid surface to a thickness of 1 lam, and a resin compact disk and a glass disk with water attached were placed. The articles to be treated are first immersed in the ethyl alcohol layer and drained for 30 seconds as usual.Then, each article to be treated, with the ethyl alcohol and the water that could not be removed, is completely soaked in the lower layer. It is immersed in a fluorinated compound solution, and drained for 30 seconds at room temperature while applying ultrasonic vibration.
Both the remaining water and the attached ethyl alcohol were separated from the article to be treated and floated to the surface without being dissolved in the fully fluorinated compound liquid, entering the ethyl alcohol layer and being removed. Thereafter, the ethyl alcohol layer in which water had been dissolved overflowed and was separated, and the article to be treated was pulled up.

As a result, in both the resin compact disc and the glass disc, not only moisture but also no adhesion or stains of ethyl alcohol or fully fluorinated compounds were observed.

Example 3 was placed in a tank, a printed circuit board with flux attached was suspended above the liquid surface, and 1.1.1 trichloroethane was sprayed onto the surface to perform a flux cleaning treatment for 20 seconds. The flux is separated from the surface of the article to be treated, dissolved and allowed to fall onto the fully fluorinated compound liquid surface along with the cleaning agent to form a layer, and the article to be treated is completely removed with the unseparated flux and cleaning agent attached. The article is suspended and immersed in a fluorinated compound solution and cleaned for 30 seconds while being subjected to ultrasonic vibrations. The flux accumulated on the chemical compound liquid surface is mixed into the dissolved cleaning agent. After the cleaning agent layer in which the flux was dissolved was removed by overflowing, the article to be treated was pulled up.

As a result, no flux or re-cleaning agent adhesion or stains were observed on the printed circuit board surface.

Example 4 Ethyl alcohol was placed in the first tank, and (CsFll)3 at room temperature was placed as a fully fluorinated compound in the second tank, and a silver-plated electronic component with water attached was used as an article to be treated. The sample was first immersed in ethyl alcohol in the first tank for 30 seconds and drained, then transferred directly into the fully fluorinated compound in the second tank without drying the ethyl alcohol, immersed for 30 seconds and drained. I did this. Through these treatments, most of the water adhering to the object to be treated was first separated and floated to the surface by ethyl alcohol, but some remaining water was found, and by treatment with a fully fluorinated compound, unremoved water and adhesion were removed. Both of the ethyl alcohol that was being used separates from the surface of the article to be treated and floats to the surface. This water-dissolved ethyl alcohol can be easily removed using an overflow tank, and the treated article is pulled out of the fully fluorinated compound liquid to complete the treatment.

As a result, not only moisture but also no ethyl alcohol or fully fluorinated compounds are found on the surface of electronic components.
There was no discoloration and the water had been completely drained.

Comparative Example 1 Trichlorethylene was used as a cleaning solution, heated and maintained at 80°C, and silver-plated electronic components were immersed for 1 minute in accordance with a conventional method, followed by rinsing treatment such as ultrasonic rinsing three times. I did it.

As a result, although moisture was removed, the total processing time was 5 minutes, and the silver on the surface of the electronic component was discolored by chlorine contained in trichlorethylene.

Comparative Example 2 Freon R-113 was used as the cleaning liquid, and after applying ultrasonic waves for 30 seconds in the cleaning tank using a device for this cleaning liquid, rinsing was performed for a total of 30 seconds in the two-stage rinsing tank. The cleaning process for defluxing the mounted printed circuit board was carried out by setting the residence time in the steam generated in the third rinsing tank to 20 seconds.

As a result, the flux was removed, but the treatment time was long, the number of treatment tanks was large, complicated equipment had to be used, and the contaminants were not dissolved in the cleaning agent Freon R-113. In order to increase the amount of cleaning fluid lost, it is necessary to replenish the amount lost, and the total amount must be renewed every three or three times the cleaning process is performed diagonally.

<Effects of the Invention> The present invention performs treatment with a fully fluorinated compound after treatment with a conventional cleaning agent. It is possible to remove contaminants in the micropores that could not be removed by treatment with cleaning agents, without leaving contaminants or cleaning agent stains on the object to be treated, and without causing discoloration or deterioration of the product. There is no need to replace the fully fluorinated compound with pure water, which is necessary in conventional methods, and there is no need to replace the entire amount of the fully fluorinated compound. Remarkable effects have been observed, such as the fact that supplementation alone is sufficient.

Claims (1)

[Claims] 1) After treatment with at least one type of cleaning agent selected from the group consisting of alcohols, chlorinated organic solvents, petroleum-based solvents, and water-soluble detergents containing surfactants, the structure Formulas ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, (C_5F_1_1)_3N, (C_4F_9)_3N
, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ , ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ , ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ A method for washing and draining articles, characterized in that the treatment is performed using a fully fluorinated compound.