JPH11128854A - Washing method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To propose a washing method and device by which from a material to be washed that has finished washing with a cleaning agent, the cleaning agent and soil are effectively removed, a decrease in purity of rinse liquid is prevented to perform immersion rinse and vapor washing, and restocking of the soil is prevented to increase washing effect. SOLUTION: A material to be washed 3 is introduced into a washing tank 1 to wash it with a cleaning agent. The material to be washed 3 that has been washed with the cleaning agent is transferred to a first vapor washing part 9 of a finish tank 2 and is vapor washed with solvent vapor to remove most of the cleaning agent and soil stuck on the material to be washed 3. Then, the material to be washed is transferred to a rinse part 8 and is immersed in and rinsed with rinse liquid 12. The material to be washed 3 after the immersion rinse is transferred to a second vapor washing part 10 to vapor wash it with vapor of the liquid. In this washing method, liquid condensate generated in the first vapor washing process is prevented from being incorporated in the rinse liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for cleaning electronic and electrical parts, general equipment parts, precision mechanical parts, optical and glass parts, and more particularly to a cleaning method and apparatus for transferring an object to be cleaned while transferring the object. It is.

[0002]

2. Description of the Related Art Articles such as electronic / electrical parts, general equipment parts, precision mechanical parts, optical / glass parts, etc. are washed to remove oily, water-based, and other stains attached during the manufacturing and storage processes. Is performed. For the purpose of cleaning such articles, cleaning combining immersion cleaning with a solvent such as chlorofluorocarbon and trichloroethane and steam cleaning has been performed.

[0003] However, these solvents have problems in environmental protection and handling safety. Therefore, as an alternative, cleaning agents such as hydrocarbon-based cleaning agents, water-based cleaning agents, and other solvent-based cleaning agents are used. The cleaning using was started. Although this cleaning agent has a strong detergency against dirt, it has a problem that the drying step is difficult, for example, it takes a long time to dry, and rust and stains are generated.

[0004] For this reason, a cleaning method has been performed in which the above-described cleaning with a cleaning agent is followed by rinsing using a rinsing liquid composed of a solvent that is easily dried. At this time, by combining the rinsing with the rinsing liquid and the vapor cleaning with the rinsing liquid vapor, the cleaning agent and dirt remaining in the previous process can be efficiently removed, and drying can be performed in a short time and in a good finished state. Can be.

In this case, generally, there is a method of immersing an object to be cleaned, which has been cleaned with a cleaning agent, in a rinsing liquid to perform immersion rinsing, and then pulling up the rinsing liquid and holding it in the vapor of the rinsing liquid to perform steam cleaning. Have been. In the immersion rinsing step, residual dirt is removed and solvent replacement is performed. In the steam cleaning step, the solvent is condensed due to the temperature difference, and the cleaning is performed in a state of high dissolving power near the vapor temperature, so that the finish cleaning is performed.

However, in such a method, if a solvent having high compatibility with the cleaning agent is used as the rinsing liquid, it is difficult to maintain a high purity of the rinsing liquid. As a result, the cleaning effect is deteriorated or the steam cleaning process needs to be lengthened because the cleaning agent or dirt in the rinsing liquid adheres to the cleaning object subjected to the immersion rinsing. Decrease.

When a solvent having low compatibility with the cleaning agent is used as the rinsing liquid, phase separation occurs, so that when the object to be cleaned is lifted, dirt may adhere to the object to be cleaned. The cleaning effect deteriorates. In this case, since the dissolving power of the rinsing liquid is low, the cleaning effect is not improved even if the steam cleaning step is lengthened.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to efficiently remove a cleaning agent and dirt from an object to be cleaned which has been cleaned with a cleaning agent, prevent a decrease in the purity of a rinsing liquid, and perform immersion rinsing and steam cleaning. The present invention proposes a cleaning method and a cleaning apparatus capable of preventing the reattachment of dirt and improving the cleaning effect.

[0009]

The present invention is the following cleaning method and apparatus. (1) a cleaning step of cleaning an object to be cleaned with a cleaning agent;
A first steam cleaning step of vapor-cleaning the object to be cleaned, which has been cleaned by the cleaning agent, with solvent vapor to remove most of the cleaning agent and dirt adhering to the object to be cleaned; A rinsing step of immersion rinsing, and a second steam cleaning step of steam-cleaning the object to be cleaned after the immersion rinsing with the vapor of the rinsing liquid, so that the condensate of the first vapor cleaning step is not mixed into the rinsing liquid. A cleaning method characterized by: (2) A cleaning tank for introducing an object to be cleaned and cleaning with a cleaning agent, and a first cleaning device for introducing the object to be cleaned cleaned with the cleaning agent.
A steam washing section, a immersion rinsing section, and a finishing tank configured to sequentially pass through the second steam washing section, wherein the finishing tank is provided with a rinsing liquid provided at a lower portion, and an immersion rinsing section, A cleaning device having a first and a second steam cleaning unit provided in an intermediate portion for storing a rinsing liquid vapor, wherein a condensate generated in the first steam cleaning unit is configured not to flow into the immersion rinsing unit . (3) The apparatus according to (2), wherein the first and second steam cleaning units are formed in the same or different spaces.

The objects to be cleaned in the present invention are articles such as electronic / electrical parts, general equipment parts, precision mechanical parts, optical / glass parts, and the like. Movable articles are suitable as targets. Such objects to be cleaned are oily, water-based, or those to which composite stains of these are adhered are to be cleaned.
Examples of the stain include flux, etching liquid, processing liquid, processing oil, and abrasive.

As the cleaning agent used in the present invention, any cleaning agent can be used, depending on the type and properties of the object to be cleaned and the stain, but generally a cleaning solution having a relatively high boiling point is used. used. Examples of such a cleaning liquid include a hydrocarbon-based cleaning liquid, an aqueous-based cleaning liquid, and other solvent-based cleaning liquids.

Examples of the hydrocarbon-based detergent include n-pentane, n-hexane, isohexane, n-heptane,
Paraffinic hydrocarbons such as isoheptane, isooctane, decane, dodecane, hexadecane and icosane; olefinic hydrocarbons such as 1-decene and 1-dodecene; naphthenic hydrocarbons such as cyclohexane and decalin; terpene hydrocarbons such as limonene and pinene. A cleaning solution containing aromatic hydrocarbons such as hydrogen, benzene, toluene, xylene, ethylbenzene, and tetralin, and hydrocarbon solvents such as petroleum ether, petroleum benzine, ligroin, and solvent naphtha, alone or in combination, or further coordinating Detergents containing additives such as compounds, alcohols, glycol ethers, esters, amides, and surfactants.

Examples of the aqueous detergent include detergents obtained by adding a surfactant, a chelating agent, an acid, an alkali and other additives to water. Examples of other solvent-based cleaning agents include alcohol-based, glycol ether-based, ester-based, and silicone-based solvents, and mixtures of these with water. If a water-containing cleaning agent is used, the water content should be 50
% By weight or less is preferred.

Among these detergents, a detergent in which an additive is blended with a hydrocarbon-based solvent is preferable. In particular, a detergent in which a coordinating compound is blended as an additive with a hydrocarbon-based solvent, or a surfactant is further used. A formulated detergent is preferred.

Here, the coordinating compound is an organic compound capable of coordinating with a metal ion, and is not particularly limited as long as it is soluble in a hydrocarbon solvent. Is a compound having an oxygen atom as a coordinating atom, and examples thereof include 1-alkyl-2-pyrrolidinone, trialkylphosphine oxide, and dialkylsulfoxide. These coordinating compounds are used in an amount of 10 to 300 g, preferably 30 to 300 g, per liter of the hydrocarbon solvent.
It is preferable to add 250 g.

The surfactant is preferably a lipophilic nonionic surfactant having a low HLB. Examples of such a surfactant include polyoxyethylene alkyl ethers, alkylamine oxides and the like, and polyether-modified surfactants. A silicone surfactant such as silicone can be used.

The rinsing liquid is used for removing the cleaning agent and the dirt adhered to the object to be cleaned. The rinsing liquid having high compatibility with the cleaning agent and the dirt is used. The power does not have to be high. The rinsing liquid is preferably nonflammable and has little effect on the environment such as global warming, and preferably has a relatively low boiling point for reducing energy in steam cleaning.

As such a rinsing liquid, a hydrogen-containing fluorinated solvent such as hydrofluorocarbon and hydrofluoroether is preferable. These hydrogen-containing fluorine-based solvents are nonflammable because they contain fluorine in the molecule, and because they contain hydrogen, their compatibility with organic dirt and hydrocarbon-based solvents is increased, and their degradability in the environment is improved. Granted,
The impact on the environment has been reduced. Commercially available CF
₃ CHFCHFCF ₂ CF ₃ (Bertrel XF, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) C ₄ F ₉ OCH ₃ (HF
E-7100, manufactured by Sumitomo 3M Limited, trademark), C ₄ F ₉ O
_{C 2 H 5 (HFE-7200} , manufactured by Sumitomo 3M Ltd., trademark) and the like.

The cleaning tank constituting the cleaning apparatus of the present invention is configured so that an object to be cleaned can be introduced and cleaned with the cleaning agent. The cleaning method may be any type such as an immersion type or a spray type. it can. In any case, it is preferable that the washing liquid is extracted, purified by distillation or the like, and circulated.

The finishing tank is provided with an immersion rinsing section at a lower portion, first and second steam cleaning sections in an intermediate section, a rinsing liquid is stored in the immersion rinsing section, and a rinsing liquid is supplied to the first and second steam cleaning sections. The apparatus is configured so that the object to be cleaned can be sequentially moved by containing the steam. In this case, the first and second steam cleaning units may be provided in different spaces, or may be provided in the same space. When they are formed in the same space, the structure is such that the first and second steam cleanings are performed one after another over time. The condensate of the condensed liquid generated in the first steam cleaning section is separated from the immersion rinsing section and is configured not to flow from the condensed liquid into the immersion rinsing section. The liquid may be configured to flow into the immersion rinsing unit, or may be configured not to flow. The immersion rinse is preferably maintained at a low temperature.

The condensed liquid in the first and second steam cleaning sections and the rinsing liquid in the immersion rinsing section are extracted and purified, and returned to the finishing tank. In this case, the first and / or second rinsing liquid vapors are heated by heating. It is preferable to return to the steam cleaning section. The first and second steam cleaning units may be configured so as to be partitioned and cleaned with different solvent vapors, but are preferably configured so as to be cleaned with the same rinsing liquid vapor without partitioning.

A drying section may be provided above the finishing tank. The drying section preferably has a structure in which the solvent vapor evaporated from the surface of the object to be cleaned is condensed by cooling with a cooling pipe. In this case, the structure in which the cooling pipe is arranged on the upper outer peripheral portion of the finishing tank facilitates the transfer of the object to be cleaned, but a suction-type drying device may be used.

In the cleaning by the above-mentioned cleaning apparatus, first, an object to be cleaned is introduced into a cleaning tank, and the object to be cleaned is brought into contact with a cleaning agent to perform cleaning. Cleaning with a cleaning agent can be performed by dipping, spraying, or other contact methods depending on the type of cleaning tank. At this time, if necessary, means such as heating and stirring can be used. Further, the number of washing tanks is not limited to one but can be increased as necessary. Further, the cleaning agent can be taken out, purified by distillation or the like, and circulated, whereby the cleaning power can be kept high. This cleaning removes oily, aqueous, and other stains attached to the object to be cleaned.

The object to be cleaned which has been cleaned in the cleaning tank is pulled up from the cleaning agent and transferred to a first steam cleaning section of the finishing tank, where it is held in a solvent vapor to perform first steam cleaning. In this steam cleaning, condensation occurs due to the temperature difference between the solvent vapor and the object to be cleaned, and most of the cleaning agent and dirt attached to the object to be cleaned are washed away by the condensed solvent. Since this solvent has a high temperature close to the vapor temperature, it has a large dissolving power, so that the cleaning agent and the dirt are efficiently washed away, the solvent is replaced, and the re-adhesion of the dirt is prevented. The solvent condensed in the first steam cleaning step is prevented from entering the immersion rinsing section.

The object to be cleaned after the first steam cleaning is transferred to an immersion rinsing section, where it is immersed in a rinsing liquid maintained at a low temperature. Rinsed. As a result, a small amount of dirt or cleaning agent immersed in the details of the object to be cleaned is removed.

Thereafter, the object to be cleaned is pulled up from the rinsing liquid and held in the second steam cleaning section to perform steam cleaning, thereby removing dirt slightly mixed in the rinsing liquid and performing final cleaning. Finally, it is preferable to remove the rinse liquid adhering to the object to be cleaned in the drying section.

In the above-mentioned cleaning, the condensate of the first vapor cleaning is taken out so as not to be mixed with the rinsing liquid, and is purified together with or separately from the rinsing liquid taken out of the immersion rinsing section by a purifying apparatus and circulated to the finishing tank. I do. At this time, it is preferable that the purified rinsing liquid is vaporized by the vapor generator and supplied to the first and second vapor cleaning units.

In this case, the refining device and the steam generating device may be one device, or may be different devices.
That is, the condensed liquid and the rinsing liquid may be purified by a filter, a distillation apparatus, or the like, and then transferred to a steam generator, or may be directly vaporized by a steam generator. The condensate generated in the second steam washing section and the drying section may be returned to the immersion rinsing section as it is, or may be directly transferred to the purification device for purification without returning to the immersion rinsing section, or may be transferred to the evaporating device for steam. It may be.

[0029]

According to the cleaning method of the present invention, the object to be cleaned is cleaned with a cleaning agent in the cleaning step, steam-cleaned in the first steam cleaning step, and immersed and rinsed in the rinsing step.
Since the steam cleaning step is further performed in the steam cleaning step, the cleaning agent and dirt can be efficiently removed from the object to be cleaned which has been cleaned with the cleaning agent. Also, by preventing the condensate generated in the first steam cleaning step from being mixed into the rinsing liquid, it is possible to perform the immersion rinsing and the steam cleaning by preventing the purity of the rinsing liquid from being reduced, thereby preventing the reattachment of dirt. It is possible to enhance the cleaning effect.

According to the cleaning apparatus of the present invention, the cleaning tank and the finishing tank are combined, and the finishing tank is provided with the first steam cleaning section, the immersion rinsing section, and the second steam cleaning section. Since the condensed liquid is prevented from flowing into the immersion rinsing section, the above-described cleaning can be efficiently performed with a simple device.

Further, by forming the first and second steam cleaning sections in the same space, the installation area can be reduced, and by forming them in different spaces, the operation can be simplified.

[0032]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are system diagrams showing another embodiment.

In FIG. 1, 1 is a cleaning tank, 2 is a finishing tank, and 3 is an object to be cleaned. The cleaning tank 1 contains a cleaning agent 4 therein, and is configured to immerse and wash the object 3 to be cleaned. At this time, stirring means such as ultrasonic vibration and oscillation is added. Has been omitted. Lines 6 and 7 are connected from the cleaning tank 1 to the purification device 5.

The finishing tank 2 is provided with a immersion rinsing section 8 at a lower portion, a first steam cleaning section 9 and a second steam cleaning section 10 at an intermediate portion, and a drying section 11 at an upper portion. The immersion rinsing unit 8 is configured to store the rinsing liquid 12 and immerse the object 3 to be rinsed to be rinsed, and a cooling device is provided at a lower portion.
The illustration is omitted. The immersion rinsing unit 8 is provided with a stirring means 13 such as ultrasonic vibration and rocking.

Immediately above the rinsing section 8, a second steam cleaning section 10
A first steam cleaning tank 9 is provided adjacent to the first steam cleaning tank 9 and partitioned by a partial partition wall 15, and is filled with a rinsing liquid vapor 14. A condensate receiver 16 is formed below the first steam cleaning section 9. Partition wall 15
As a result, the condensate generated in the first steam cleaning is
Rinsing liquid 12. The condensate receiver 16 and the purifying device 17
Lines 18 and 19 communicate with each other, a line 20 communicates with the steam generator 21 from the purifier 17, and a line 22 communicates with the second steam cleaning unit 10 from the steam generator 21.

A cooling pipe 23 is provided on the outer periphery of the drying section 11, and a condensate receiver 24 is provided below the cooling pipe 23. The condensed liquid receiver 24 communicates with the immersion rinsing unit 8 so that the condensed liquid flows down. The article to be cleaned 3 is configured to be suspended from a hanger and moved, but is not shown.

In the cleaning by the above-described cleaning apparatus, first, the object 3 to be cleaned is introduced into the cleaning tank 1, and the object 3 to be cleaned is
And washing. At this time, dissolution of dirt is promoted by heating and stirring. The cleaning agent 4 is withdrawn from the line 6 to the purifying device 5, purified by distillation or the like, and circulated from the line 7 to the cleaning tank 1, whereby the cleaning power can be kept high. This cleaning removes dirt such as oiliness and water attached to the object 3 to be cleaned.

The object 3 to be cleaned which has been cleaned in the cleaning tank 1
Is lifted from the cleaning agent 4 and transferred to the first steam cleaning section 9 of the finishing tank 2, where it is held in the rinsing liquid vapor 14 to perform first steam cleaning. This steam cleaning is performed by rinsing liquid vapor 14
Condensation occurs due to the temperature difference between the cleaning object 3 and the cleaning object 3, and most of the cleaning agent and dirt attached to the cleaning object 3 are washed away by the condensed rinsing liquid. Since the rinsing liquid has a high temperature close to the vapor temperature, the rinsing liquid has a large dissolving power, the cleaning agent and the dirt are efficiently washed away, the solvent is replaced, and the re-adhesion of the dirt is prevented. The solvent condensed in the first steam cleaning step is sent from the line 18 to the purification device 17 without being mixed into the immersion rinsing section.

The article 3 to be cleaned after the first steam cleaning is transferred to the immersion rinsing section 8 where it is immersed in the rinsing liquid 12 maintained at a low temperature, and is subjected to agitation such as ultrasonic irradiation and rocking. Rinsed. As a result, a small amount of dirt or cleaning agent immersed in the details of the object to be cleaned 3 is removed.

Thereafter, the object 3 to be cleaned is pulled up from the rinsing liquid 12 and held in the second steam cleaning section 10 to perform steam cleaning, thereby removing dirt slightly mixed in the rinsing liquid, and performing final cleaning. Done. The condensate in the second steam cleaning flows down to the rinsing section 8 as it is.

Thereafter, when the object to be cleaned 3 is pulled up, the drying unit 1
After passing through 1, the rinsing liquid vapor in the drying unit 11 is condensed by the cooling pipe 23, so that the rinsing liquid attached to the article 3 to be cleaned is evaporated and condensed by the cooling pipe 23. As a result, the object to be cleaned 3 dries, and the cleaning is completed. Cooling pipe 23
The condensed liquid condensed by is collected in the condensed liquid receiver 24 and flows down to the rinsing section 8.

In the above-mentioned cleaning, the condensate of the first steam cleaning is collected in the condensate receiver 16 so as not to be mixed with the rinsing liquid and is taken out from the line 18. The solution is refined together with or separately from the refiner 17 and circulated to the finishing tank 2. At this time, the purified rinsing liquid is vaporized by the steam generator 21 and supplied to the first and second steam cleaning units 9 and 10.

In this case, the refining device and the steam generating device are separate devices, but may be one device. The condensate generated in the second steam cleaning section 10 and the drying section 11 is returned to the rinsing section 8 as it is, but is not returned to the immersion rinsing section 8 but is directly transferred to the purifying apparatus 17 for purification or the steam generating apparatus. 21 and may be vaporized.

In the above-described cleaning method, the object to be cleaned 3 is cleaned in the cleaning tank 1 with a cleaning agent, steam-cleaned in the first steam cleaning section 9, immersed and rinsed in the immersion rinsing section 8, and subjected to the second steam cleaning. Since the steam cleaning is further performed in the section 10, it is possible to efficiently remove the cleaning agent and dirt from the object to be cleaned which has been cleaned with the cleaning agent.

In this case, the object 3 to be cleaned is
The rinsing effect can be enhanced by removing most of the cleaning agent and dirt attached to the rinsing liquid. However, when the condensate generated here flows into the immersion rinsing section 8, the rinsing liquid 1 is removed.
2 rapidly reduces the rinsing effect due to the re-adhesion of dirt. Therefore, in the present invention, the condensed liquid generated in the first steam cleaning section 9 is collected by the condensed liquid receiver 16 and sent to the refining device 17 without being mixed in the immersion rinsing section 8 to purify, so that the rinsing effect is maintained high. Can be.

FIG. 2 shows another embodiment. Here, the first and second steam cleaning sections 9 and 10 are provided in the same space, and can be switched over time by the position of the movable partition 25. It has become. 26 is the rotation axis.

In the above-described apparatus, the solid line position in FIG. 2 shows the state of use as the first steam cleaning section 9 and the movable partition 2
Reference numeral 5 denotes a gentle inclined state which is almost horizontal, and the condensed liquid condensed on the object 3 to be washed thereover flows down the movable partition 25 and is collected in the condensed liquid receiver 16, and is sent from the line 18 to the purification device 17.

When used as the second steam cleaning unit 10 and when the object 3 to be cleaned is transferred to the rinsing unit 8,
The movable partition 25 is moved to a position indicated by a broken line 25 around the rotation axis 26.
a at this position, the object 3 to be cleaned is transferred to the rinsing section 8 to perform a rinsing step, and the second steam cleaning section 10
And perform steam cleaning. The condensate at this time flows down to the rinsing section 8. Other configurations and operations are the same as those in FIG.

In the cleaning apparatus shown in FIG. 2, the first and second steam cleaning sections 9 and 10 are formed in the same space.
Although the installation area of the device is small, the driving operation is complicated.
On the other hand, in the apparatus shown in FIG. 1, the first and second steam cleaning sections 9 and 10 are formed in different spaces, so that the installation area is large but the operation is simple.

[0050]

Embodiments of the present invention will be described below.

Example 1 Printed circuit board (80 × 120 mm) including surface mount components
To be cleaned, and chlorocut PC101 as a cleaning agent.
(Kurita Kogyo Co., Ltd., trademark, hydrocarbon-based precision cleaning agent) was placed in the cleaning tank 1 and subjected to ultrasonic irradiation at 40 ° C. for 2 minutes for immersion cleaning. 1 was used as a finishing tank, and HFE-7100 manufactured by Sumitomo 3M Limited was used as a rinsing liquid.
The first steam cleaning, the immersion rinsing, the second
Was subjected to steam washing and drying.

The above results are shown in Table 1. When the appearance of the object to be cleaned was observed after washing with a new cleaning agent, it was found that the object to be cleaned was completely dried. In addition, the flux residue is 0.5
Washing was performed with the same detergent dissolved at a concentration of about 2.5 wt%, but the rinse liquid was kept in a clean state, and the finish did not deteriorate.

[0053]

[Table 1]

Comparative Example 1 A test was conducted in the same manner as in Example 1 except that the first steam cleaning step was omitted.

The results are shown in Table 2. As a result of observing the appearance of the object to be cleaned after cleaning with a new cleaning agent, it was found that the object to be cleaned was completely dried. However, when a cleaning agent in which a flux is dissolved is used, the cleaning liquid becomes cloudy when the object to be cleaned is immersed in the rinsing portion, and the rinsing liquid becomes cloudy. As a result of observing the surface of the object to be cleaned after the cleaning, when the flux concentration in the cleaning agent becomes 1.0 wt% or more, deposition of the precipitate has come to be observed.

[0056]

[Table 2]

From the above results, it can be seen that an excellent washing effect can be obtained by performing steam washing in the first steam washing tank and purifying and circulating the condensate in the refining apparatus without mixing the condensate in the rinse liquid. Recognize.

[Brief description of the drawings]

FIG. 1 is a system diagram of a cleaning device according to an embodiment.

FIG. 2 is a system diagram of a cleaning apparatus according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cleaning tank 2 Finishing tank 3 Object to be cleaned 4 Cleaning agent 5,17 Purification device 6,7,18,19,20,22 Line 8 Immersion rinsing part 9 First steam cleaning part 10 Second steam cleaning part 11 Drying Part 12 Rinse liquid 13 Stirring means 14 Rinse liquid vapor 15 Partition wall 16, 24 Condensed liquid receiver 21 Steam generator 23 Cooling pipe 25 Movable partition wall 26 Rotating shaft

Claims (3)

[Claims] A cleaning step of cleaning the object to be cleaned with a cleaning agent; and a vapor cleaning of the object to be cleaned cleaned with the cleaning agent with a solvent vapor to remove most of the cleaning agent and stain adhering to the object to be cleaned. A first steam cleaning step of removing, a rinsing step of immersing and rinsing the object to be cleaned with a rinsing liquid, and a second steam cleaning step of vapor rinsing the object to be cleaned after immersion rinsing with steam of the rinsing liquid. And a condensate in the first steam cleaning step is prevented from being mixed into the rinsing liquid. 2. A cleaning tank for introducing an object to be cleaned and cleaning it with a cleaning agent, a first steam cleaning section, an immersion rinsing section, and a second steam cleaning for introducing an object to be cleaned cleaned by the cleaning agent. A immersion rinsing unit provided at a lower portion for storing a rinsing liquid, and a first immersion rinsing unit provided at an intermediate portion for storing a rinsing liquid vapor. And a second steam cleaning unit, wherein the condensate generated in the first steam cleaning unit is configured not to flow into the immersion rinsing unit. 3. The apparatus according to claim 2, wherein the first and second steam cleaning sections are formed in the same or different spaces.