JPH04354573A - Washing device - Google Patents

Abstract

PURPOSE:To provide the washing device which can attain the defoaming purpose by application of mechanical means. CONSTITUTION:The water tank of the washing device for rinsing the matter to be washed with the washing water 2 which is pumped up from the water tank 1 and is jetted by a jetting section installed above the water surface of the water tank has a water receiving section 7 gently inclining from one end of the water tank toward the other end between the jetting section and the water surface. A discharge port 8 is provided at the inclining low end of the water receiving section and a downcomer 9 extending from the discharge port down to the underside of the water surface of the water tank is provided at the discharge port. This kind of the washing device having mechanically defoaming function and being satisfactory in all phases of washability, operability and cost is thereby obtd.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device that can deal with foam generated during a water cleaning operation by applying a mechanical foam extinguisher.

0002

[Prior Art and Its Problems] Rosin-based solder flux is used in the production of modules such as printed circuit boards and printed wiring boards. The purpose of soldering is generally to increase the adhesive strength between the board and the input/output pins, and to prevent oxidation of the contacts and maintain conductivity.In order to make the soldering process more effective, rosin-based Solder flux is used. After soldering is completed, a cleaning agent is used to selectively and completely remove only the flux from the board surface. That is, if the cleaning of the flux is insufficient, there is a disadvantage that the residual flux causes circuit corrosion or decreases the electrical insulation of the substrate surface, which ultimately leads to circuit damage. Therefore, the disadvantages mentioned above are overcome by using cleaning agents to remove the residual flux, especially the activator components contained therein.

Conventionally, halogenated hydrocarbon solvents such as so-called chlorofluorocarbons such as trichlorethylene and trichlorotrifluoroethane have been used as cleaning agents for rosin-based solder flux. Although these halogen-based cleaning agents have the advantage of being nonflammable and having excellent drying properties, their use is being strictly regulated due to environmental pollution problems such as ozone layer depletion, and the electrical industry is There is also an urgent need to develop a solder flux cleaning agent that can replace fluorocarbons.

In response to this situation, various non-halogen solder flux cleaning agents, such as saponification type, hydrocarbon solvent type, and higher alcohol type, have recently been developed and are being put on the market. There are advantages and disadvantages compared to others. For example, in the case of alkaline saponification type, there is no problem of flammability because it is an aqueous solution type, but when cleaning, it is necessary to contact the liquid for a long time under heating, resulting in low cleaning efficiency. There are disadvantages such as concerns about corrosion of the parts. On the other hand, in the case of cleaning agents such as hydrocarbon solvent type and higher alcohol type, cleaning power, toxicity, odor, etc.
At present, no material has yet been found that completely satisfies all performance requirements such as flammability.

By the way, the inventors of the present invention have made extensive studies to solve the above problem, and have developed a mixture containing a specific glycol ether compound, a nonionic surfactant, and water as essential components, and furthermore, a mixture containing a specific glycol ether compound, a nonionic surfactant, and water as essential components. In addition, it has been found that the above problems can be solved when a mixture containing a polyoxyalkylene phosphate surfactant as an essential component is used. That is, we have completed an invention related to a non-halogen solder flux cleaning agent that has excellent cleaning power and is substantially satisfactory in terms of environmental characteristics, odor, flammability, etc., as well as a cleaning method using the cleaning agent, and have already obtained a patent. I filed an application.

[0006] However, all of these various fluorocarbon alternative cleaning agents require a water rinsing step. Although the water rinsing process yields objects to be cleaned with excellent cleanliness, on the other hand, severe foaming occurs during water rinsing, which is disadvantageous in terms of operation and the like.

Conventionally, to deal with these foaming problems,
Methods such as using a hydrophobic surfactant, using the active ingredient itself as a hydrophobic solvent, and further adding an antifoaming agent are used. However, these methods have advantages and disadvantages; for example, if a hydrophobic substance is used, foaming can be suppressed, but rinsing performance becomes poor, or problems arise in wastewater treatment. On the other hand, the method using antifoaming agents is disadvantageous in terms of cost and operation, and there is also the problem that the antifoaming agents remain on the printed circuit board, so an effective solution has not yet been established. not present.

The present invention attempts to eliminate the above-mentioned problems by dealing with the above-mentioned foaming by applying a mechanical defoaming means.

[0009]

[Means for Solving the Problems] The present invention is a cleaning device that washes objects to be cleaned with washing water that is pumped up from a water tank and sprayed from a spray unit installed above the water surface of the water tank. between the injection part and the water surface, a water receiver is provided that gently slopes from one end of the water tank to the other end, and a discharge port is formed at the lower end of the inclination of the water receiver; The present invention relates to a cleaning device characterized by being provided with a downcomer pipe portion extending from the mouth to below the water surface of the water tank.

The apparatus of the present invention cleans and removes flux from a printed circuit board using, for example, a rosin-based solder flux cleaning agent, and then removes the cleaning agent remaining on the substrate.
Applicable for cleaning with water jetted from the jetting section.

[0011] Normally, bubbles are generated during water cleaning using jet water, where the cleaning water encloses air, where the jet water hits the substrate (object to be cleaned), where the jet water falls onto the water surface, etc. be.

[0012] In the device of the present invention, the bubbles generated in the injection section fall onto the water receiving section installed below and flow down along the slope of the section. Naturally disappears due to etc.

The remaining bubbles fall onto the water surface in the aquarium through the outlet opening from the lower inclined end of the water receiver and the drop pipe connected thereto. At the same time, the washing water that falls also generates new bubbles on the surface of the falling water.

[0014] Since the downcomer section extends below the water surface and prevents the above-mentioned bubbles from diffusing to the surrounding area, all the bubbles remain within the water surface section within the downcomer section. As cleaning water falls one after another from the outlet into the area where the foam accumulates, the foam is destroyed one after another by the impact of the falling water, so the amount of accumulated foam does not increase unnecessarily. It can be kept in small amounts at all times.

As described above, according to the device of the present invention, it is possible to mechanically eliminate bubbles generated at the spraying section and the surface of the water where the cleaning water falls.

[0016] In the device of the present invention, the water receiving portion is for once receiving the washing water and foam falling from the spraying portion, and allowing some of the foam to disappear naturally on the way down along the slope. It serves as a partition to separate the spray part from the water surface of the aquarium. If the slope of the water receiving part is too large, the amount of bubbles generated at the falling part of the water surface will increase due to the high flow rate of the washing water, and if it is too small, it will be difficult to expect the bubbles to disappear naturally at a low flow rate. Usually 1~10℃
It is selected and determined as appropriate from the angle range of the degree.

[0017] The discharge port is for collecting the washing water and foam flowing down along the slope of the water receiving part and letting them fall onto the water surface of the aquarium, and is formed at the lower end of the slope of the water receiving part. As long as the formation position and planar shape are not particularly limited. The forming position is preferably at the low end of the slope, especially at the corner, as this can maximize the average distance from the point at which the bubbles descend to reach the outlet, and thus the natural disappearance of the bubbles. It may be in the middle of two corners or on a line connecting two equal corners. In addition, the planar shape is generally circular if the formation location is a corner, but
Depending on the formation position, the shape may be a polygon, a slit, or the like.

The downcomer pipe portion prevents bubbles that have fallen onto the water surface from the discharge port from spreading to the surrounding area, and at the same time prevents bubbles generated on the falling water surface portion from spreading to the surrounding area. The latter bubbles occur both on the water surface and below the water surface, so it is necessary for the downcomer pipe to extend below the water surface. Usually it extends to near the bottom of the aquarium, but in some cases it may extend between the water surface and the bottom. It may end somewhere between. The cross-sectional shape of the downcomer section usually corresponds to the planar shape of the outlet, but is not necessarily limited to this.

[0019] The pump that sends cleaning water toward the injection section generates bubbles when air is sucked in, so the water intake port should be opened as close to the bottom of the water tank as possible, and as far away from the downcomer pipe section as possible. It is preferable. With the spacing between the water inlet and the downcomer section, there is no risk that the pump will suck in foam from the lower end of the downcomer section. If a partition extending from the water surface to near the bottom of the tank is provided between the water inlet and the downcomer pipe, preferably closer to the water inlet side, bubbles can be more reliably prevented from being trapped.

The apparatus of the present invention can be applied to water cleaning of solder flux cleaning agent remaining on printed wiring boards, etc., and to cleaning various objects to be cleaned with water that may cause foaming.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

The cleaning water 2 contained in the water tank 1 is supplied to the pump 3.
The water is sent from the water intake port 4 to the injection section 6 through the conduit 5.

The spraying units 6 are installed above the water surface 2a of the water tank 1 with left and right pairs facing each other, and spray water onto the object a to be cleaned inserted within the installation interval to clean it.

[0024] The water tank 1 is provided with a water receiving part 7 between the spray parts 6, 6 and the water surface 2a, and the part 7 functions as a partition to isolate the water surface 2a from the spray parts 6, 6. .

[0025] The upper surface of the water receptacle 7 has a diagonal direction (see Fig. 2).
A gentle inclination of about 5° is made toward the lower end of the inclination, and a discharge port 8 is formed at the corner portion on the lower end of the inclination.

A downcomer section 9 extends downwardly from the outlet 8, and its lower end terminates near the bottom of the water tank 1, as shown in FIG.

The water inlet 4 is connected to the downcomer section 9 as shown in FIG.
A partition 10 is located at the lower part of the side wall on the opposite side to the pipe section.

[0028] The partition 10 is located closer to the water inlet 4 side,
A liquid passage port 11 is formed below the lower end of the partition 10, extending from the lower surface of the water receiving portion 7 to near the bottom of the water tank 1.

The object to be cleaned, for example, a printed wiring board, is sprayed and cleaned with cleaning water between the spraying units 6, 6 as shown in the figure. The solder flux cleaning agent washed away from the substrate during this cleaning is dissolved in the cleaning water, and the cleaning water becomes foamable due to the dissolution of the cleaning agent.

Bubbles are generated at the location where the cleaning water hits the object to be cleaned, and these bubbles are absorbed by the water receiving plate 7 below the cleaning water.
It falls upward and flows down along the slope of the section 7. During the flow, some of the bubbles naturally disappear and disappear due to contact with air.

The remaining bubbles fall onto the water surface 2a in the water tank 1 from the lower inclined end of the water receiving portion 7 through a discharge port 8 opening therein and a downcomer pipe portion 9 connected to the port 8. At the same time, new bubbles are generated on the surface of the falling water due to the falling washing water.

Bubbles that have fallen onto the water surface 2a and bubbles newly generated on the water surface 2a are prevented from dispersing to the surrounding area by the downcomer section 9 extending downward from the water surface 2a.
The water remains at the water surface 2a in the downcomer pipe section 9 and stagnates therein.

[0033] Washing water falls into the area where the foam accumulates at the same time as the foam, and the foam is destroyed one after another by the impact of the falling washing water, so the amount of accumulated foam is not substantially increased. Therefore, the object to be cleaned (a) can be washed with water without the risk of bubbles overflowing from the outlet 8.

[0034] The washing water after being used for impact destruction of foam is
The small bubbles returned from the lower end of the downcomer pipe section 9 into the water tank 1 and accompanied by the wash water float above the water surface 2a due to buoyancy. Thus, the cleaning water from which air bubbles have been removed passes through the liquid passage port 11 below the lower end of the partition 10, thereby preventing air from being trapped in the pump 3 and thereby preventing the generation of air bubbles.

[0035]

[Effect] According to the cleaning device of the present invention, the purpose of defoaming can be achieved by applying mechanical means, so all the problems that occur when using defoaming agents and hydrophobic surfactants are eliminated. It can satisfy all aspects of cleaning, operability, and cost.

[Brief explanation of drawings]

FIG. 1 is a longitudinal end view schematically showing an embodiment of the present invention.

FIG. 2 is a plan view of the same.

[Explanation of symbols]

1　Aquarium 2　Washing water 3 Pump 4 Water intake 5 Conduit 6 Injection part 7 Water receiving part 8 Discharge port 9 Downcomer section 10 Partition 11 Liquid passage port

Claims (1)

[Claims] Claim 1: A cleaning device that washes objects to be cleaned with washing water that is pumped up from a water tank and sprayed from a spraying part installed above the water surface of the water tank, wherein the water tank is provided between the spraying part and the water surface. The water tank has a water receiving part that gently slopes from one end to the other end, and a discharge port is formed at the lower inclined end of the water receiving part, and the discharge port has a water receiving part that extends from the mouth to below the water surface of the tank. A cleaning device characterized by being provided with a downcomer pipe section for discharging water.