JP3515668B2 - Ultrasonic cleaning method and ultrasonic cleaning device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic cleaning method and an ultrasonic cleaning apparatus for ultrasonically cleaning an object to be cleaned (a work) in which dust or the like is attached to a minute gap or the like.

[0002]

2. Description of the Related Art For example, instead of scrub cleaning using a brush or the like, ultrasonic cleaning is applied to a cleaning liquid in a state in which the cleaning liquid is immersed in a cleaning liquid for dusts adhering to minute gaps. Ultrasonic cleaning is widely used.

Conventionally, in this kind of ultrasonic cleaning, a cleaning liquid is previously put in an ultrasonic cleaning tank, a work is immersed in the cleaning liquid and set, and then an ultrasonic oscillator attached to the ultrasonic cleaning tank is used. The cleaning liquid was driven to apply ultrasonic waves. Therefore, the inside of the ultrasonic cleaning tank was always under atmospheric pressure.

[0004]

However, in the above-mentioned conventional ultrasonic cleaning, for example, as shown in FIG.
When ultrasonic cleaning is performed with the work W having the bag hole H inside being set with the opening of the bag hole H facing downward, an air pocket in which the cleaning liquid does not enter the inside of the bag hole H occurs, There is a problem that the inside of the bag hole H cannot be washed.

If the ultrasonic cleaning cannot be performed in this way, it is necessary to clean the inside of the bag hole H by another cleaning method. This is the same in the case where air is sometimes trapped between the works, for example, when the works are brought into close contact with each other, or when the works are superposed one on top of the other, such as close cleaning of the lead frame.

[0006] In view of the above, the present invention ensures that even a work having a portion into which the cleaning liquid does not enter even if it is simply immersed in the cleaning liquid or a work group in which air sealed inside may occur. An object of the present invention is to provide an ultrasonic cleaning method and an ultrasonic cleaning device that can perform ultrasonic cleaning.

[0007]

The ultrasonic cleaning method of the present invention comprises the steps of immersing an object to be cleaned in a cleaning solution in an ultrasonic cleaning tank and applying ultrasonic vibration to the cleaning solution to clean the object to be cleaned. It is characterized in that the pressure in the ultrasonic cleaning tank is repeatedly changed to deaerate the cleaning liquid while applying ultrasonic vibration to the cleaning liquid. Further, the ultrasonic cleaning device of the present invention,
In an ultrasonic cleaning apparatus for immersing an object to be cleaned in a cleaning solution in an ultrasonic cleaning tank and applying ultrasonic vibration to the cleaning solution to clean the object to be cleaned, the ultrasonic cleaning tank is provided to deaerate the cleaning solution. Pressure fluctuation means for repeatedly varying the pressure of 1. and ultrasonic wave application means for applying ultrasonic vibration to the cleaning liquid when the cleaning liquid is degassed.

According to the present invention thus constructed, for example, the air enclosed in the bag hole of the work or between the works closely contacting each other repeats expansion and contraction as the pressure of the ultrasonic cleaning tank changes, Thus, it can be determined promptly by using an ultrasonic cleaning allowed to enter the cleaning fluid into the air reservoir by air confined.

Here, the fluctuation of the pressure in the ultrasonic cleaning tank can be performed by repeating vacuuming and vacuum breaking in the ultrasonic cleaning tank.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an ultrasonic cleaning apparatus used for ultrasonic cleaning according to the present invention. As shown in FIG. 1, this ultrasonic cleaning apparatus has an ultrasonic cleaning device in which a cleaning liquid 1 for cleaning is put. A tank 2 is provided, and the ultrasonic cleaning tank 2 is configured to be sealed by an opening / closing lid 3, and an ultrasonic oscillator 4 is attached to the bottom of the tank 2.

The ultrasonic cleaning tank 2 is connected to a vacuum pump 5 for vacuuming the air in the upper space S therein, and a pipe 6 connecting the ultrasonic cleaning tank 2 and the vacuum pump 5 is connected.
A vacuum exhaust valve 7 is provided in the middle of the process. Further, the ultrasonic cleaning tank 2 is provided with a vacuum break valve 8 that breaks (leaks) the vacuum in the upper space S.

Then, the opening / closing lid 3 is opened, the work to be cleaned (object to be cleaned) is dipped and set in the ultrasonic cleaning tank 2, the opening / closing lid 3 is closed, and the ultrasonic oscillator 4 is placed in this state. Ultrasonic cleaning is performed by driving and applying ultrasonic vibration to the cleaning liquid 1.

Here, as shown in detail in FIG. 2, when a work W having a bag hole H inside is set with the bag hole H facing downward and ultrasonic cleaning is performed, the bag hole H of the work W is left as it is. The cleaning liquid 1 does not enter into the inside of the bag hole H without being released, and therefore the inside of the bag hole H cannot be ultrasonically cleaned.

Therefore, while the ultrasonic cleaning is being performed, the internal pressure p ₀ of the upper space S of the ultrasonic vibration tank 2 is changed to deaerate the cleaning liquid 1 to cope with this. ing.

That is, the pressure in the upper space S when the work W is set in the ultrasonic cleaning tank 2 is the same as the atmospheric pressure.
Atmospheric pressure, and the pressure of the air enclosed in the bag hole H is also 1 atm. Therefore, while driving the vacuum pump 5,
As shown in FIG. 3, the vacuum exhaust valve 7 is operated during the time t _{1 to} t _2.
And the internal space S is depressurized from the pressure p ₁ (atmospheric pressure) to the pressure p ₂ .

Then, assuming that the height from the surface of the cleaning liquid 1 to the inlet of the bag hole H is h (see FIG. 1), the density of the cleaning liquid 1 is ρ, and the acceleration of gravity is g, the pressure p at the inlet of the bag hole H is p.
Becomes p = p ₂ + ρgh, which is lower than 1 atm.

Therefore, the air contained in the bag hole H of the work W expands so as to be equal to the pressure p, and escapes from here. Next, during the time t _{2 to} t ₃ , the vacuum exhaust valve 7 is closed and the vacuum break valve 8 is opened to change the internal space S of the ultrasonic cleaning tank ₂ from the pressure p ₂ to the atmospheric pressure p ₁ . return.

Then, since the pressure of the air remaining in the bag hole H is reduced as described above, this pressure difference p
_The cleaning liquid 1 flows into the bag hole H of the work W with a force of _1- p ₂ .

By repeating the evacuation and the vacuum breaking of the ultrasonic cleaning tank 2 during the ultrasonic cleaning, the cleaning liquid 1 is permeated into the inside of the bag hole H of the work W, and the ultrasonic waves inside the cleaning liquid 1 are penetrated. Washing can be done.

This also applies to cleaning when the works are in close contact with each other, such as contact cleaning of the lead frame, and cleaning when the works overlap each other, and air is enclosed in the contact surfaces of the works to cause air pockets. Even if the cleaning is performed, the vacuum cleaning and the vacuum breaking of the ultrasonic cleaning tank are repeated during the ultrasonic cleaning to allow the cleaning liquid 1 to permeate the inside of the air pocket to perform the ultrasonic cleaning.

Moreover, by degassing the cleaning liquid in the ultrasonic cleaning tank in this way, the cleaning time can be shortened and the cavitation force of ultrasonic waves can be improved.

[0022]

As described above, according to the present invention,
For example, even if there are workpieces that have bag holes where the cleaning liquid does not enter, or there is a risk that air will be trapped between the workpieces that are in close contact with each other, etc., let the cleaning liquid enter the air pool due to the enclosed air and Sonic cleaning can be performed, thereby eliminating the need for a separate cleaning.

Moreover, the cleaning period is shortened and
The cavitation force of ultrasonic waves can be improved.

[Brief description of drawings]

FIG. 1 is a schematic view of an ultrasonic cleaning apparatus used for ultrasonic cleaning of the present invention.

FIG. 2 is likewise a perspective view showing a work.

FIG. 3 is a graph showing the relationship between the pressure in the ultrasonic cleaning tank and time in the ultrasonic cleaning method of the present invention.

[Explanation of symbols]

1 cleaning liquid 2 Ultrasonic cleaning tank 4 Ultrasonic oscillator 5 vacuum pump 7 Vacuum exhaust valve 8 Vacuum break valve

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Claims (4)

(57) [Claims] 1. When cleaning an object to be cleaned by immersing the object to be cleaned in a cleaning solution in an ultrasonic cleaning tank and cleaning the object to be cleaned by applying ultrasonic vibration to the cleaning solution, the cleaning solution is repeatedly changed in pressure in the ultrasonic cleaning tank. An ultrasonic cleaning method, wherein ultrasonic vibration is applied to the cleaning liquid while degassing the inside. 2. The ultrasonic cleaning method according to claim 1, wherein the fluctuation of the pressure in the ultrasonic cleaning tank is performed by repeating vacuuming and vacuum breaking in the ultrasonic cleaning tank. 3. An ultrasonic cleaning apparatus for cleaning an object to be cleaned by immersing the object to be cleaned in a cleaning liquid in an ultrasonic cleaning tank and applying ultrasonic vibration to the cleaning liquid, wherein the cleaning liquid is degassed. An ultrasonic cleaning apparatus comprising: a pressure fluctuation unit that repeatedly changes the pressure in the ultrasonic cleaning tank; and an ultrasonic wave application unit that applies ultrasonic vibration to the cleaning liquid when degassing the cleaning liquid. 4. The ultrasonic cleaning apparatus according to claim 3, wherein the pressure changing means repeats vacuuming and vacuum breaking in the ultrasonic cleaning tank.