JPH05123657A - Method for cleaning body to be cleaned - Google Patents

Abstract

PURPOSE:To produce an ultrasonic cleaning effect on a body to be cleaned while using a cleaning liq. having high viscosity such as a water insoluble terpene solvent, a silicon contg. solvent, a hydrocarbon solvent or hydrophilic higher alcohol. CONSTITUTION:A body 7 to be cleaned is first cleaned by immersion in a cleaning liq. 1 having high viscosity. It is then immersed in an ultrasonic cleaning liq. 6 based on a perfectly fluorinated liq. and ultrasonic cleaning is carried out to remove contaminants remaining in the recess, etc., in the body 7 after cleaning in the cleaning liq. 1 having high viscosity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to mechanical parts, electronic parts,
The present invention relates to a method for cleaning an object to be cleaned such as a printed circuit board.

[0002]

2. Description of the Related Art Conventionally, in a cleaning liquid such as a fluorine-based solvent or a chlorine-based solvent, which is capable of chemically removing contaminants when it is desired to remove contaminants adhering to an object to be cleaned reliably and to perform precision cleaning. It has been common practice to apply ultrasonic waves to the object to be cleaned while the object to be cleaned is immersed in the object.

[0003]

However, the use of fluorine-based solvents, chlorine-based solvents, etc. has been restricted because of environmental damage. Therefore, it is considered to use a terpene solvent, a silicon-based solvent, a hydrocarbon-based solvent, a hydrophilic solvent such as a higher alcohol, for the cleaning liquid, but these are all highly viscous solvents, and ultrasonic waves The ultrasonic cavitation generated from the oscillator is attenuated by the highly viscous cleaning liquid before reaching the object to be cleaned, and the ultrasonic cleaning effect cannot be generated or significantly reduced.

Therefore, the filth separated from the object to be cleaned due to contact with the highly viscous cleaning liquid cannot be removed from the concave portion of the object to be cleaned and remains, so that high precision cleaning cannot be performed. It had a flaw.

The present invention is intended to solve the above-mentioned problems, and provides a highly viscous cleaning liquid such as a water-insoluble terpene solvent, a silicone solvent, a hydrocarbon solvent, and a higher alcohol such as a hydrophilic solvent, It is intended to make it possible to obtain an ultrasonic cleaning effect on an object to be cleaned while using it for cleaning the object to be cleaned.

[0006]

In order to solve the above-mentioned problems, the present invention is performed by immersing an object to be cleaned in a highly viscous cleaning solution, and then cleaning the object to be cleaned with a completely fluorinated liquid. It is characterized in that it is immersed in an ultrasonic cleaning liquid as a main component and ultrasonic cleaning is performed in this ultrasonic cleaning liquid.

Further, another invention is a cleaning liquid having high viscosity,
An ultrasonic cleaning liquid containing a perfluorinated liquid as a main component is mixed in a cleaning tank, and an object to be cleaned is immersed in the mixed liquid to perform ultrasonic cleaning.

Further, the highly viscous cleaning liquid may be a terpene solvent, a silicon solvent, a hydrocarbon solvent or a hydrophilic solvent.

The highly viscous solvent may have a viscosity of 2 cP or more at 20 ° C.

The ultrasonic cleaning liquid containing a perfluorinated liquid as a main component may have a viscosity of less than 2 cP at 20 ° C.

[0011]

In order to carry out the work of cleaning the object to be cleaned by the method of the present invention,
First, the object to be cleaned is immersed in a highly viscous cleaning liquid having a viscosity of 20 ° C. of 2 cP or more to perform cleaning. As the highly viscous cleaning liquid, hydrophilic solvents such as terpene solvent, silicon solvent, hydrocarbon solvent, and higher alcohol are considered. These highly viscous cleaning liquids do not allow effective ultrasonic cleaning of the objects to be cleaned, because the ultrasonic waves are attenuated even if the objects to be cleaned immersed in the cleaning solution are subjected to ultrasonic cleaning. ..

However, these highly viscous cleaning liquids are effective for chemically dissolving or peeling the dirt of the object to be cleaned. Therefore, it is possible to dissolve or peel the dirt from the object to be cleaned, but because the physical force of ultrasonic waves does not act, the melted or peeled dirt remains in the recesses of the object to be cleaned, It cannot be reliably removed.

Therefore, in the present invention, after cleaning the object to be cleaned by immersing the object to be cleaned in a highly viscous cleaning liquid,
Ultrasonic cleaning is carried out by immersing in an ultrasonic cleaning liquid whose main component is a completely fluorinated liquid. This ultrasonic cleaning liquid is selected so that the viscosity is less than 2 cP at 20 ° C. in the fully fluorinated liquid.

The ultrasonic cleaning liquid containing a perfluorinated liquid as a main component has a viscosity of less than 2 cP at 20 ° C.
The transmissibility of ultrasonic cavitation is extremely good. For this reason, for the object to be cleaned that dissolves or peels the dirt in the highly viscous cleaning liquid, the dirt remaining in the recesses can be reliably removed from the object to be cleaned by the physical force of ultrasonic cavitation. You will be able to.

The ultrasonic cleaning liquid containing a perfluorinated liquid as a main component is not rinsed and rinsed, but ultrasonic cavitation as a physical force is applied to the object to be cleaned.
It acts as an ultrasonic cleaning liquid. Therefore, as long as the viscosity is such that the attenuation of ultrasonic cavitation does not occur, the ultrasonic cleaning liquid can repeatedly use the object to be cleaned that has been cleaned with the highly viscous cleaning liquid for ultrasonic cleaning.

[0016] In another invention, a highly viscous cleaning liquid and an ultrasonic cleaning liquid containing a perfluorinated liquid as a main component are mixed in a cleaning tank, and an object to be cleaned is immersed in the mixed liquid. It is also possible to carry out ultrasonic cleaning.

In this case, since the cleaning liquid having a high viscosity is mixed in the ultrasonic cleaning liquid, the ultrasonic cleaning effect is reduced as compared with the ultrasonic cleaning using only the ultrasonic cleaning liquid.
This eliminates the trouble of cleaning the object to be cleaned twice and enables simple ultrasonic cleaning of the object to be cleaned.

[0018]

EXAMPLE An example of the present invention will be described below with reference to FIG. 1. (1) is a solvent cleaning tank, which contains a terpene solvent, a silicon solvent, a hydrocarbon solvent, a hydrophilic solvent such as a higher alcohol. As described above, the highly viscous cleaning liquid (2) is filled. The high-viscosity cleaning liquid (2) has a viscosity of 2 cP or more at 20 ° C., and a higher alcohol has a viscosity of about 7 cP.

In this solvent cleaning tank (1), an ultrasonic vibrator (3) is formed on the lower bottom, and when the amount of the cleaning liquid (2) is small and the attenuation is not large, ultrasonic cleaning is carried out though it is insufficient. , Can be performed in combination with chemical cleaning. This solvent cleaning tank
The ultrasonic cleaning in (1) may not be performed when the amount of the cleaning liquid (2) is large. Further, the ultrasonic transducer (3) does not necessarily have to be provided.

An ultrasonic cleaning tank (4) is formed adjacent to the solvent cleaning tank (1). In this ultrasonic cleaning tank (4),
An ultrasonic transducer (5) is installed on the bottom and an ultrasonic cleaning liquid (6) whose main component is a completely fluorinated liquid is filled. This ultrasonic cleaning liquid (6) has a viscosity of 2 cP or less at 20 ° C. Then, the solvent cleaning tank (1) is added to the ultrasonic cleaning liquid (6) whose main component is the completely fluorinated liquid.
To be cleaned with the highly viscous cleaning solution (2)
(7) is immersed and washed by ultrasonic cavitation.

Before performing the cleaning by the ultrasonic cavitation, the object to be cleaned (7) is cleaned by the highly viscous cleaning liquid (2) in the solvent cleaning tank (1). The cleaning of the object to be cleaned (7) with this highly viscous cleaning liquid (2)
It is effective for chemically dissolving or peeling the dirt of (7). Therefore, it is possible to dissolve or remove the dirt from the object to be cleaned (7), but since the physical force of ultrasonic waves does not sufficiently act, the dissolved or separated dirt is removed from the object to be cleaned (7). It cannot be surely removed from the concave portion of ().

Therefore, the object to be cleaned (7) washed with a highly viscous cleaning liquid is immersed in an ultrasonic cleaning liquid (6) containing a perfluorinated liquid as a main component, and the ultrasonic cleaning liquid (6) is immersed in the ultrasonic cleaning liquid (6). Ultrasonic cleaning. The ultrasonic cleaning liquid (6) whose main component is a completely fluorinated liquid has a viscosity of less than 2 cP at 20 ° C., and therefore has an extremely good ultrasonic cavitation transmissivity.

Therefore, the object to be cleaned (7) in which the dirt is dissolved or peeled in the highly viscous cleaning liquid (2), the dirt remaining in the recesses is physically removed by ultrasonic cavitation. By the force, it is possible to surely remove the object to be cleaned (7), and it is possible to perform highly precise cleaning.

A finishing tank adjacent to the ultrasonic cleaning tank (4)
The object to be cleaned (7) which has formed (8) and has been subjected to ultrasonic cleaning can be subjected to any operation such as rinsing cleaning or drying operation.

In the embodiment shown in FIG. 1, the object to be cleaned is
Ultrasonic cleaning was carried out by moving (7) from the solvent cleaning tank (1) to the ultrasonic cleaning tank (4). However, it is not always necessary to move the object to be cleaned (7), and as shown in FIG. 2, the object to be cleaned (7) is placed in the common cleaning tank (10) which doubles as a solvent cleaning tank and an ultrasonic cleaning tank.
, Which is a highly viscous cleaning liquid without moving to another tank.
It is also possible to perform the cleaning in (2) and the cleaning with an ultrasonic cleaning liquid (6) containing a perfluorinated liquid as a main component.

In this method, a cleaning liquid tank (11) and an ultrasonic cleaning liquid tank (12) are shared by a cleaning tank (10) through discharge pumps (13) (14) and introduction pumps (15) (16). Connect to. Then, the cleaning liquid tank (11) is filled with a highly viscous cleaning liquid (2) such as a terpene solvent, a silicon solvent, a hydrocarbon solvent, or a hydrophilic solvent such as higher alcohol. Further, the ultrasonic cleaning liquid tank (12) is filled with the ultrasonic cleaning liquid (6) containing a perfluorinated liquid as a main component.

Then, from the cleaning liquid tank (11), the cleaning liquid (2) of high viscosity is shared by the introduction pump (15) in the common cleaning tank.
Introduced into (10), the object to be cleaned (7) is washed. After cleaning with this highly viscous cleaning liquid (2) is completed, the common cleaning tank
The cleaning liquid (2) is restored and discharged from (10) to the cleaning liquid tank (11) by the discharge pump (13).

Next, the introduction pump (16) is operated to introduce the ultrasonic cleaning liquid (6) whose main component is the completely fluorinated liquid from the ultrasonic cleaning liquid tank (12) into the common cleaning tank (10).
Then, the object to be cleaned (7) is ultrasonically cleaned with the ultrasonic cleaning liquid (6).

In the cleaning method according to this embodiment, it is necessary to move the object to be cleaned (7) in order to perform cleaning with the highly viscous cleaning liquid (2) and ultrasonic cleaning with the ultrasonic cleaning liquid (6). In addition, it is possible to obtain an inexpensive device because there is no need for a quick cleaning operation and a moving mechanism.

In each of the above embodiments, the solvent cleaning tank (1), the common cleaning tank (10), or the cleaning liquid tank (1)
Multiple combinations of 1) etc. were used. However, in another different embodiment, as shown in FIG. 3, one common cleaning tank (10) has an ultrasonic cleaning liquid (2) having a high viscosity and an ultrasonic cleaning liquid containing a low-viscosity perfluorinated liquid as a main component. (6) and filling at the same time, only by this one common cleaning tank (10),
It is possible to perform ultrasonic cleaning with the ultrasonic cleaning liquid (6) as well as cleaning with the highly viscous cleaning liquid (7).

According to the above-mentioned cleaning method, cleaning with the highly viscous cleaning liquid (2) by one common cleaning tank (10),
Since ultrasonic cleaning with the ultrasonic cleaning liquid (6) can be performed, inexpensive cleaning work can be performed with an inexpensive device.

In the above cleaning method, the ultrasonic transducer
The ultrasonic cleaning liquid (6) must be located on the side that comes into contact with (5). Then, with the highly viscous cleaning liquid (2), the object to be cleaned
After performing the cleaning of (7), if the same cleaning tank (10) is moved upward or downward and ultrasonic cleaning is performed in the ultrasonic cleaning liquid (6), the cleaning target (7) can be cleaned. Complete.

According to this embodiment, one common cleaning tank
The cleaning is completed in (10), which enables a quick cleaning operation with an inexpensive device. Further, in this embodiment, the ultrasonic cleaning liquid (6) containing a perfluorinated liquid as a main component and the highly viscous cleaning liquid (2) cause some mixing due to the action of ultrasonic vibration. It does not significantly reduce the cleaning effect.

Further, if the ultrasonic vibration is made stronger than in the above-mentioned embodiment, the highly viscous cleaning liquid and the ultrasonic cleaning liquid containing the perfluorinated liquid as the main component have a strong physical force of ultrasonic waves. As a result, a mixed state is obtained in the common cleaning tank, but it is also possible to immerse the object to be cleaned in this mixed solution for ultrasonic cleaning.

In this case, since the cleaning liquid having a high viscosity is mixed in the ultrasonic cleaning liquid, the ultrasonic cleaning effect is reduced as compared with the ultrasonic cleaning using only the ultrasonic cleaning liquid.
This eliminates the trouble of cleaning the object to be cleaned twice and enables simple ultrasonic cleaning of the object to be cleaned.

In each of the above examples, the ultrasonic cleaning liquid containing a perfluorinated liquid as a main component was used at room temperature. By heating the ultrasonic cleaning liquid to a temperature higher than room temperature, the viscosity of the ultrasonic cleaning liquid is increased. It may be further lowered.

Further, by using the completely fluorinated liquid, it is possible to reduce the influence on the environment and to carry out a safe cleaning operation of the object to be cleaned without danger of ignition.

[0038]

As described above, the present invention dissolves or exfoliates dirt in a highly viscous cleaning solution most suitable for removing chemical dirt from the object to be cleaned, and ultrasonically cavifies the dirt left in the recesses or the like. It is possible to reliably remove from the object to be cleaned by the physical force of the.

Therefore, it is possible to add the effect of ultrasonic cleaning to the cleaning operation with the highly viscous cleaning liquid, and the ultrasonic cleaning effect with the highly viscous cleaning liquid, which was difficult in the past, can be obtained, and it is possible to obtain a high degree of cleaning. It enables precision cleaning.

In another invention, a highly viscous cleaning liquid,
An ultrasonic cleaning solution consisting mainly of a completely fluorinated liquid is mixed in a cleaning tank, and an object to be cleaned is immersed in this mixed solution to perform ultrasonic cleaning. Compared with the above, although the ultrasonic cleaning effect is reduced, the number of steps of cleaning the object to be cleaned twice is eliminated, and the simple ultrasonic cleaning of the object to be cleaned becomes possible.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a second embodiment of the present invention.

FIG. 3 is a schematic diagram showing a third embodiment of the present invention.

[Explanation of symbols]

 1 Cleaning liquid 6 Ultrasonic cleaning liquid 7 Object to be cleaned

Claims (5)

[Claims] 1. An object to be cleaned is immersed in a highly viscous cleaning solution for cleaning, and then the object to be cleaned is immersed in an ultrasonic cleaning solution containing a perfluorinated liquid as a main component. A method for cleaning an object to be cleaned, characterized in that ultrasonic cleaning is performed therein. 2. A highly viscous cleaning liquid and an ultrasonic cleaning liquid whose main component is a completely fluorinated liquid are mixed in a cleaning tank, and an object to be cleaned is immersed in the mixed liquid to carry out ultrasonic cleaning. A method for cleaning an object to be cleaned, comprising: 3. The method for cleaning an object to be cleaned according to claim 1, wherein the highly viscous cleaning liquid is a terpene solvent, a silicon solvent, a hydrocarbon solvent, or a hydrophilic solvent. 4. A highly viscous solvent has a viscosity of 2 at 20.degree.
The method for cleaning an object to be cleaned according to claim 1, wherein the cleaning rate is not less than cP. 5. The method for cleaning an object to be cleaned according to claim 1, wherein the ultrasonic cleaning liquid containing a perfluorinated liquid as a main component has a viscosity of less than 2 cP at 20 ° C.