JPH0523649A - Cleaning device - Google Patents

Abstract

PURPOSE:To provide cleaning equipment where ignition potential is small and explosion can be prevented even when cleaning with cleaning liquid having combustible properties. CONSTITUTION:Cleaning equipment using cleaning liquid of combustible organic solvent consists of a spray cleaning tank 2 to clean a printed circuit board 1, a carrying-in liquid seal tank 3 to carry the printed circuit board 1 in the spray cleaning tank 2, and a carrying-out liquid seal tank 4 to carry the printed circuit board 1 out of the spray cleaning tank 2. The printed circuit board 1 is cleaned in the spray cleaning tank 2 into which inert gas 9 is introduced so that the spray cleaning tank 2 may be isolated from the air by a jet of sealing liquid 16 and the oxygen concentration may be not more than the prescribed one. The introduced quantity of the inert gas 9 is controlled by an oxygen analyzer 12, a gas analyzer 13 for the cleaning liquid 5 and a thermometer 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device, and particularly to a cleaning device using a flammable organic solvent as a cleaning liquid, which is effective when applied to a cleaning device capable of obtaining an explosion-proof structure against gas and mist of the cleaning liquid. Regarding

[0002]

2. Description of the Related Art Conventionally, in a cleaning device for printed circuit boards, electronic parts, etc., for example, CFC or 1.1.
Chlorine-based organic solvents such as 1 trichloroethane have been used.

That is, since these organic solvents are non-flammable liquids, it is not necessary to devise the gas and mist of the cleaning liquid generated in the cleaning process, especially from the viewpoint of explosion proof.

A related device of this type is, for example, a cleaning device described in Japanese Patent Publication No. 62-9240.

[0005]

However, in the above-mentioned prior art, no consideration is given from the viewpoint of preventing ignition of the cleaning liquid. For example, when cleaning with a flammable liquid, ignition always occurs. And the problem of explosion proof arises.

The chlorine-based organic solvent that has been used conventionally has the advantage that it is nonflammable, but on the other hand, it has been pointed out that the ozone layer in the atmosphere is destroyed and that groundwater is contaminated. Therefore, cleaning with an alternative cleaning solution that has flammability will become necessary in the future.

Therefore, an object of the present invention is to provide a cleaning device capable of reducing the potential of ignition and ignition and preventing explosion even when cleaning with a cleaning liquid having a flammable property.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0009]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

That is, the cleaning apparatus of the present invention is a cleaning apparatus having a cleaning chamber for cleaning an object to be cleaned, and a carry-in chamber and a carry-out chamber for carrying in or carrying out the object to be cleaned. A liquid discharge port is provided on at least one of the upper and lower parts of the carry-in chamber carry-in port and the carry-out chamber carry-out port, and the seal liquid is discharged from this liquid discharge port.
An inert gas is introduced into the cleaning chamber surrounded by the liquid discharge port.

Further, the seal liquid discharged from the liquid discharge port is returned to the cleaning chamber, and the seal liquid is separated from the cleaning liquid due to the difference in specific gravity and then discharged again from the liquid discharge port.

Further, oxygen concentration measuring means for measuring the oxygen concentration is provided inside the cleaning chamber, and the flow rate of the inert gas is adjusted so as to obtain a predetermined oxygen concentration.

Further, another cleaning apparatus of this embodiment comprises gas concentration measuring means for measuring the gas concentration of the cleaning liquid used in the internal space of the cleaning chamber and inert gas introducing means for introducing an inert gas into the cleaning chamber. Is provided to control the amount of inert gas introduced according to the gas concentration of the cleaning liquid.

Further, another cleaning apparatus of the present invention is provided with a liquid temperature measuring means for measuring the liquid temperature of the cleaning liquid in the cleaning chamber and an inert gas introducing means for introducing an inert gas into the cleaning chamber, and The amount of inert gas introduced is controlled according to the liquid temperature.

In this case, the oxygen concentration in the cleaning chamber is measured, and the operation of the cleaning liquid supply pump is stopped when the oxygen concentration is higher than a predetermined oxygen concentration.

[0016]

According to the above-mentioned cleaning device, the cleaning chamber is shielded from the outside by the discharge of the sealing liquid, and the inert gas is introduced into the cleaning chamber. It can be carried out in a cleaning room sealed with an active gas. That is, it is possible to easily seal the inside of the cleaning chamber with the inert gas without flowing out the inert gas introduced into the cleaning chamber that is shielded from the outside air to the outside.

As a result, even if the concentration of the cleaning liquid gas in the cleaning chamber rises to the explosive range during the cleaning of the object to be cleaned, the oxygen concentration can be reduced to a certain value or less by the replacement with the inert gas, so that ignition and ignition are prevented. This can be prevented, and at the same time, the inert gas does not flow out to the outside, so that the consumption amount of the inert gas can be reduced.

In this case, the ignition and ignition potentials can be reduced by controlling the amount of the inert gas introduced so that the oxygen concentration in the cleaning chamber space will always be a constant amount. As a result, explosion protection can be further achieved, and the consumption of inert gas can be further reduced.

Further, by measuring the gas concentration or liquid temperature of the cleaning liquid in the atmosphere of the cleaning chamber and controlling the oxygen concentration by controlling the amount of the inert gas introduced depending on the ignition and ignition potential, an explosion can occur. Can be reduced. This makes it possible to further improve safety.

Further, when the seal liquid and the cleaning liquid can be mixed, the discharged seal liquid can be returned to the cleaning chamber and discharged again from the liquid discharge port. In other words, the inlet and outlet of the cleaning chamber can be provided with an inclination to allow the sealing liquid to flow into the cleaning chamber, and the cleaning liquid and the sealing liquid can be separated in the cleaning chamber by the difference in specific gravity. The size and size of the cleaning device can be reduced.

[0021]

[Embodiment 1] FIG. 1 is a schematic configuration diagram showing a cleaning apparatus according to an embodiment of the present invention.

First, the construction of the cleaning apparatus of this embodiment will be described with reference to FIG.

The cleaning device of this embodiment is a cleaning device using a cleaning liquid of a flammable organic solvent, for example, and a spray cleaning tank (cleaning chamber) 2 for cleaning a printed circuit board (object to be cleaned) 1 and a printed circuit board. 1 is carried into the spray cleaning tank 2, and a carry-in liquid sealing tank (carrying-in chamber) 3 and a carry-out liquid sealing tank (carrying-out chamber) 4 for carrying out the printed circuit board 1 from the spray cleaning tank 2 are provided. Cleaning of the substrate 1 is performed in a spray cleaning tank 2 sealed with a liquid and an inert gas.

The spray cleaning tank 2 stores a flammable cleaning liquid 5 such as a second petroleum or the like on the bottom surface thereof, and a spray nozzle 7 for ejecting the cleaning liquid 5 onto the printed circuit board 1 carried by the conveyor 6. A cleaning liquid pump 8 for supplying the cleaning liquid 5 to the spray nozzle 7 is provided. The spray nozzles 7 are disposed above and below the spray cleaning tank 2, and the cleaning liquid 5 is ejected from both spray nozzles 7 by driving the cleaning liquid pump 8 to spray-clean the printed circuit board 1.

Further, an inert gas 9 such as nitrogen or argon gas is introduced into the spray cleaning tank 2 via a flow valve (inert gas introducing means) 10, and further, a necessary flow valve 11 for discharge is used. The spray cleaning tank 2 is evacuated accordingly, and the spray cleaning tank 2 is sealed with an inert gas 9.

Further, in the spray cleaning tank 2, an oxygen concentration meter (oxygen concentration measuring means) 12 for measuring the oxygen concentration in the internal space and a gas concentration meter (gas concentration measuring means) for measuring the gas concentration of the cleaning liquid 5 are provided. And 13 are provided. And
The oxygen concentration meter 12 adjusts the flow rate of the inert gas 9 so that the internal space of the spray cleaning tank 2 has a predetermined oxygen concentration, and the amount of the inert gas 9 introduced according to the gas concentration measured by the gas concentration meter 13. Controlled. Further, a thermometer (liquid temperature measuring means) 14 is disposed at a position of the spray cleaning tank 2 where the cleaning liquid 5 is immersed, and the amount of the inert gas 9 introduced is controlled according to the liquid temperature of the cleaning liquid 5. .

Then, the oxygen concentration meter 12 and the gas concentration meter 13
And the measurement information of the oxygen concentration by the thermometer 14, the gas concentration of the cleaning liquid 5, and the liquid temperature are sent to the controller 15,
The controller 15 controls the flow valves 10 and 11 to control the supply and exhaust of the inert gas 9.

The carry-in liquid seal tank 3 stores, for example, non-combustible seal liquid 16 such as water or perfluorocarbon on the bottom surface thereof, and shuts off the atmosphere from the spray cleaning tank 2 connected to the carry-in liquid seal tank 3. A seal nozzle 17 for jetting the seal liquid 16 for supplying the seal liquid 16 and a seal liquid pump 18 for supplying the seal liquid 16 to the seal nozzle 17 are provided. Then, the seal nozzle 17 is used as the carry-in liquid seal tank 3
The seal liquid 16 is disposed above and below, and the seal liquid 16 is jetted from both seal nozzles 17 by driving the seal liquid pump 18.
The inlet to the spray cleaning tank 2 is formed so as to be sealed from the atmosphere.

The carry-out liquid seal tank 4 has the same structure as the carry-in liquid seal tank 3, and a non-combustible seal liquid 19 such as water or perfluorocarbon is stored in the bottom surface of the carry-out liquid seal tank 4 and the atmosphere and the carry-out liquid seal tank 4 A seal nozzle 20 that jets a seal liquid 19 that shuts off the spray cleaning tank 2 connected to the seal cleaning tank 2 and a seal liquid pump 21 that supplies the seal liquid 19 to the seal nozzle 20 are provided. Then, the seal nozzles 20 are arranged above and below the carry-out liquid seal tank 4, and the seal liquid 19 is jetted by driving the seal liquid pumps 21 from both the seal nozzles 20 to seal the carry-out port from the spray cleaning tank 2 from the atmosphere. It is formed in the structure.

Next, the operation of this embodiment will be described.

First, the seal liquid pump 18 of the carry-in liquid seal tank 3 installed in the carry-in section of the equipment and the seal liquid pump 21 of the carry-out liquid seal tank 4 installed in the carry-out section are started. Then, the seal liquids 16 and 19 are jetted from the respective seal nozzles 17 and 20 of the carry-in and carry-out liquid seal tanks 3 and 4, respectively, so that the atmosphere inside the spray cleaning tank 2 is shut off from the atmosphere.

Further, in a state where the inside of the spray cleaning tank 2 is shut off from the atmosphere, the flow valve 10 is opened by the control of the controller 15 to introduce the inert gas 9 into the spray cleaning tank 2. At the same time, open the exhaust flow valve 11,
By introducing the inert gas 9, the oxygen in the spray cleaning tank 2 is exhausted to the atmosphere and replaced with the inert gas 9, so that the oxygen concentration is lowered.

In this case, when the oxygen concentration meter 12 installed in the internal space of the spray cleaning tank 2 reaches a preset safe oxygen concentration, the cleaning liquid pump 8 is activated to start spray cleaning with the cleaning liquid 5. . At the same time, the oxygen concentration in the spray cleaning tank 2 is controlled by opening / closing the flow valve 10 so that the oxygen concentration in the spray cleaning tank 2 is always below a certain value.

For example, as in this embodiment, the inert gas 9
When nitrogen or argon gas is used as the cleaning liquid and the second petroleum is used as the cleaning liquid 5, it is effective to set the oxygen concentration in the spray cleaning tank 2 to 7 to 8% or less.

At this time, for example, if an abnormality occurs in the flow valve 10, etc., and if the oxygen concentration in the spray cleaning tank 2 rises above a predetermined concentration due to this abnormality, the cleaning liquid pump is immediately stopped to detect the abnormality. Investigate the cause of the occurrence.

Therefore, according to the cleaning apparatus of the present embodiment, the spray cleaning tank 2 for cleaning the printed circuit board 1 is provided with the carry-in liquid seal tank 3 at the carry-in port and the carry-out liquid seal tank 4 at the carry-out port to carry out the spray cleaning. The tank 2 is filled with the sealing liquid 16,19
The printed circuit board 1 can be spray-washed in an atmosphere having an oxygen concentration of a predetermined value or less with the inert gas 9 by using the flammable cleaning liquid 5 because the ignition and ignition potentials are reduced. It is possible to obtain an explosion-proof structure that can ensure safety even when applied to a cleaning device.

Regarding the introduction of the inert gas 9 into the spray cleaning tank 2, for example, when the temperature of the cleaning liquid 5 rises and approaches the flash point by the measurement of the thermometer 14 installed in the cleaning liquid 5, It is also possible to open the flow valve 10 according to the gas concentration value of the cleaning liquid 5 by the gas concentration meter 13 to control the introduction of the inert gas 9, and by using these in combination, it is possible to further secure safety. Becomes

[0038]

[Embodiment 2] FIG. 2 is a schematic diagram showing a cleaning apparatus according to another embodiment of the present invention.

The cleaning device of this embodiment is a cleaning device using a cleaning liquid of a flammable organic solvent, for example, and as shown in FIG. 2, a spray cleaning tank (cleaning chamber) for cleaning the printed circuit board (object to be cleaned) 1a. ) 2a, a carry-in liquid seal part (carry-in chamber) 3a for carrying the printed circuit board 1a into the spray cleaning tank 2a, and a carry-out liquid seal part (carry-out room: carry-in for carrying out the printed circuit board 1a from the spray cleaning tank 2a). (The figure and the part numbers are omitted because it has the same configuration as the liquid seal portion 3a). The difference from the first embodiment is that it does not have a carry-in and carry-out liquid seal tank for storing the seal liquid. The point is that the cleaning liquid and the sealing liquid are separated and stored in the spray cleaning tank 2a.

That is, the spray cleaning tank 2a of this embodiment.
As shown in FIG. 2, the bottom surface is formed to have an inclination, and for example, water or a sealing liquid 16a such as perfluorocarbon having a different specific gravity is in the lower layer, and the upper layer is a flammable material such as EC-7R (manufactured by Petrofarm USA). Cleaning liquid 5a is stored separately. The suction port of the seal liquid pump 18a is installed on the bottom surface of the spray cleaning tank 2a, while the suction port of the cleaning liquid pump 8a is provided at a predetermined height from the bottom surface.

Further, the spray cleaning tank 2a is integrally provided with a carry-in liquid seal portion 3a which is a carry-in port and a carry-out liquid seal portion which is a carry-out portion. The carry-in liquid seal portion 3a and the carry-out liquid seal portion are provided with slopes on their bottom surfaces so that the seal liquid 16a jetted from the seal nozzle 17a by the drive of the seal liquid pump 18a returns to the bottom surface portions.

Therefore, in the cleaning apparatus of this embodiment,
By driving the seal liquid pump 18a, the seal liquid 16a is jetted from the respective seal nozzles 17a of the carry-in liquid seal portion 3a and the carry-out liquid seal portion, and the jetted seal liquid 16a is discharged from the carry-in liquid seal portion 3a and the carry-out liquid seal portion. Return to the spray cleaning tank 2a along the slope,
It is separated from the cleaning liquid 5a by the difference in specific gravity without being dissolved and is stored in the lower layer of the cleaning liquid 5a.

As a result, the internal atmosphere of the spray cleaning tank 2a and the atmosphere can be shut off as in the first embodiment, and at the same time, the flow valve (inactive) is measured based on the measurement by the oxygen concentration meter (oxygen concentration measuring means) 12a. The controller 15a can control the opening and closing of the gas introducing means) 10a to adjust the flow rate of the inert gas 9a so that the internal space of the spray cleaning tank 2a has a predetermined oxygen concentration.

That is, according to the cleaning apparatus of this embodiment,
At the carry-in port of the spray cleaning tank 2a, a carry-in liquid seal portion 3a,
By providing the carry-out liquid seal portion at the carry-out port, the printed circuit board 1a conveyed by the conveyer conveyor 6a is washed with the cleaning liquid from the spray nozzle 7a in an oxygen concentration atmosphere of a predetermined value or less in a state of being shielded from the air as in the first embodiment. 5a
Can be spray washed with.

This makes it possible to obtain an explosion-proof structure in which the potential for ignition and ignition is reduced and safety can be ensured. At the same time, since the cleaning device is integrally formed, the sealing mechanism can be simplified and downsized as compared with the first embodiment, manufacturing can be facilitated, and the installation space can be reduced.

Although the invention made by the present inventor has been specifically described based on the first and second embodiments, the present invention is not limited to the above-mentioned embodiments and various modifications are possible without departing from the scope of the invention. It goes without saying that it can be changed.

For example, in the cleaning device of each of the above-described embodiments, the case where the non-combustible liquid such as water or perfluorocarbon is used as the sealing liquids 16 and 16a has been described, but the present invention is limited to the above-mentioned embodiments. Instead, for example, in the case of the first embodiment, it is possible to use the same liquid as the cleaning liquid 5.

When the ignitability of the cleaning liquids 5 and 5a is not so high, liquid sealing is not performed and the amount of the inert gas 9 and 9a introduced is controlled based on the oxygen concentration in the spray cleaning tanks 2 and 2a. In addition, in combination with this, depending on the gas concentration of the cleaning liquid 5, 5a and the liquid temperature, an inert gas 9, 9a
The method of controlling the introduction of is also sufficiently effective.

Further, the case where the second petroleum combustible organic solvent is used as the cleaning liquids 5 and 5a has been described, but the present invention is not limited to this, and other combustible cleaning liquids can be applied, and It goes without saying that the sealing liquids 16 and 16a can also be applied to other liquids.

In each of the above embodiments, the case where the cleaning device is applied to cleaning the printed circuit boards 1 and 1a has been described, but it can be widely applied to cleaning other objects to be cleaned such as electronic parts. is there.

In the above description, the invention made by the present inventor was mainly applied to the cleaning apparatus using the cleaning liquids 5 and 5a of the flammable organic solvent, which is the field of application thereof, but the invention is not limited to this. Instead, it can be widely applied to cleaning devices using other cleaning liquids such as non-flammable cleaning liquids.

[0052]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.
It is as follows.

(1). A liquid discharge port is provided on at least one of an upper part and a lower part of a carry-in port of a carry-in chamber for carrying in an object to be cleaned into a cleaning chamber and a carry-out chamber for carrying out an object to be carried out. In addition to discharging the seal liquid more, introducing an inert gas into the cleaning chamber surrounded by the liquid discharge port,
By cleaning the object to be cleaned in the cleaning chamber that is sealed with the seal liquid and the inert gas, the oxygen concentration can be reduced to a certain value or less by replacing the inert gas, and it is possible to prevent ignition and ignition. At the same time, the consumption of the inert gas can be reduced.

(2). The inside of the cleaning chamber is provided with oxygen concentration measuring means for measuring the oxygen concentration, gas concentration measuring means for measuring the gas concentration of the cleaning liquid, or liquid temperature measuring means for measuring the liquid temperature of the cleaning liquid. By controlling the amount of inert gas introduced according to the oxygen concentration in the room, the flammable gas concentration, and the temperature of the cleaning liquid, it is possible to reduce the possibility of explosion due to ignition and ignition. It is possible to further improve the reduction of the consumption of the inert gas.

(3) The seal liquid discharged from the liquid discharge port is returned to the cleaning chamber, separated from the cleaning liquid due to the difference in specific gravity, and then discharged again from the liquid discharge port.
When the sealing liquid and the cleaning liquid can be mixed, the sealing mechanism can be simplified and the cleaning device can be downsized at the same time, which facilitates the manufacturing and reduces the installation space. .

(4) Due to the above (1) to (3), it is possible to easily seal the atmosphere in the cleaning chamber with an inert gas even when applied to an in-line type cleaning device using a conveyor or the like. Therefore, it is possible to provide a cleaning device in which a combustible organic solvent can be used as the cleaning liquid.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a cleaning apparatus that is Embodiment 1 of the present invention.

FIG. 2 is a schematic configuration diagram showing a cleaning device that is Embodiment 2 of the present invention.

[Explanation of symbols]

1,1a Printed circuit board (cleaning object) 2,2a Spray cleaning tank (cleaning room) 3 carry-in liquid seal tank (carry-in room) 3a Carry-in liquid seal part (carry-in room) 4 Export liquid sealing tank (export chamber) 5,5a cleaning liquid 6,6a Conveyor 7,7a spray nozzle 8.8a cleaning liquid pump 9,9a Inert gas 10, 10a Flow valve (inert gas introduction means) 11 Flow valve 12, 12a Oxygen concentration meter (oxygen concentration measuring means) 13 Gas concentration meter (gas concentration measuring means) 14 Thermometer (liquid temperature measuring means) 15,15a controller 16,16a Seal liquid 17,17a Seal nozzle 18, 18a Seal liquid pump 19 seal liquid 20 seal nozzle 21 Seal Liquid Pump

Claims (8)

[Claims] 1. A cleaning device comprising a cleaning chamber for cleaning an object to be cleaned, and a carry-in chamber and a carry-out chamber for carrying in or carrying out the object to be cleaned into the cleaning chamber. A liquid discharge port is provided in at least one of an upper part and a lower part of the carry-in port and the carry-out port of the carry-out chamber, the seal liquid is discharged from the liquid discharge port, and the inside of the cleaning chamber surrounded by the liquid discharge port A cleaning apparatus, wherein an inert gas is introduced into the cleaning chamber, and the object to be cleaned is cleaned in the cleaning chamber sealed with the sealing liquid and the inert gas. 2. The seal liquid discharged from the liquid discharge port is returned to the cleaning chamber, and the seal liquid is separated from the cleaning liquid due to a difference in specific gravity and then discharged again from the liquid discharge port. The cleaning device described. 3. The oxygen concentration measuring means for measuring the oxygen concentration is provided inside the cleaning chamber, and the flow rate of the inert gas is adjusted so as to obtain a predetermined oxygen concentration. The cleaning device described. 4. A cleaning apparatus having a cleaning chamber for cleaning an object to be cleaned, comprising gas concentration measuring means for measuring a gas concentration of a cleaning liquid used in an internal space of the cleaning chamber, and the cleaning chamber. An inert gas introducing means for introducing an inert gas is provided, and the introduction amount of the inert gas is controlled according to the gas concentration of the cleaning liquid. 5. The cleaning apparatus according to claim 1 or 2, further comprising the gas concentration measuring means and the inert gas introducing means according to claim 4. 6. A cleaning device having a cleaning chamber for cleaning an object to be cleaned, comprising: a liquid temperature measuring means for measuring a liquid temperature of a cleaning liquid in the cleaning chamber; and an inert gas introduced into the cleaning chamber. And an inert gas introducing unit for controlling the amount of the inert gas introduced according to the temperature of the cleaning liquid. 7. The liquid temperature measuring means and the inert gas introducing means according to claim 6 are provided.
Or the cleaning device according to 2. 8. The cleaning apparatus according to claim 1, wherein the oxygen concentration in the cleaning chamber is measured, and the operation of the cleaning liquid supply pump is stopped when the oxygen concentration is equal to or higher than a predetermined oxygen concentration.