JPH0596220A - Work drying method in work cleaning apparatus - Google Patents

Abstract

PURPOSE:To dry within a short time a work, whose cleaning is completed, in an apparatus for cleaning a work such as circuit substrates, metal parts, etc. CONSTITUTION:After a work being washed with a cleaning liquid consisting of a surfactant in a cleaning process 1, the rinsing liquid is washed off in a rinsing process 2. In the rinsing process 2, as a liquid for rinsing, an aqueous solution in which an alcohol-based solvent is added is used. Due to the alcohol- based solvent, water adhering to the work's surface is removed and the surface tension of the water adhering to the work's surface becomes low. As a result, in a drying process 3, drying of the work cleaning of which is already done is completed within a short time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work cleaning device for cleaning works such as circuit boards, metal parts and plastics. More specifically, the present invention relates to a work drying method in such a work cleaning device.

[0002]

2. Description of the Related Art Generally, a work cleaning apparatus for cleaning a work such as a circuit board has a cleaning unit for cleaning the work with a cleaning liquid, a rinse unit for cleaning the cleaning liquid from the cleaned work, and a drying work. It is basically composed of a drying section. Although chlorofluorocarbon has been conventionally used as the cleaning liquid, in recent years, the influence of chlorofluorocarbon on air pollution has become a problem, and a method for efficiently cleaning a work using a cleaning liquid instead of chlorofluorocarbon has been proposed. For example, the following methods have been proposed.

(1) A method of washing a work with water using a surfactant (2) A method of washing a work with only water (3) A method of washing a work with an alcohol solvent (4) A terpene solvent How to wash a workpiece using

[0004]

Such a method has some problems that must be solved in terms of efficiency.

Among these, particularly serious problems are that it takes a long time to dry the work and that the surface tension of water is large, so that the liquid is poorly drained.

An object of the present invention is to propose a method of drying a work in a work cleaning apparatus which can solve these problems.

[0007]

In order to solve the above-mentioned problems, the present invention provides a method for rinsing a work surface with a cleaning liquid, or a process of transferring from a rinsing process to a drying process with respect to the surface of the work An aqueous solution mixed with a hydrophilic solvent is applied. For example, in a drying step, a work is immersed in a tank of such an aqueous solution, and then the work is pulled out of the tank and dried by a method such as heating or air blowing.

As the hydrophilic solvent, it is preferable to use an alcoholic solvent such as isopropanol.
Particularly, a mixture of water and 12.2 wt% of isopropanol is particularly preferable because it becomes an azeotropic mixture.
Further, it is desirable to always control the mixing ratio of the hydrophilic solvent.

[0009]

In the method of the present invention, an aqueous solution containing a hydrophilic solvent is applied to a work after a washing step. By applying such an aqueous solution, the water remaining on the surface of the work is removed, and the surface tension of the residual water is reduced, so that the liquid runs out. Therefore, the work is dried quickly.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

An example of a work cleaning method to which the present invention is applied will be described with reference to FIG. The illustrated example includes a work cleaning step 1, a work rinse step 2, and a work drying step 3. In the work cleaning step 1, an aqueous solution 1a containing a surfactant is used as the cleaning liquid, and the aqueous solution 1a is stored in the storage tank 1b. A work (not shown) is immersed in the storage tank 1b, and shaken up and down or left and right in this to wash the work. A heater 1c is arranged in the storage tank 1b to heat the aqueous solution 1a to a set temperature, thereby enhancing the cleaning efficiency.

In the next rinse step 2, the cleaned work is immersed in a storage tank 2b which stores a solution 2a of city water or pure water mixed with an alcohol solvent. As in the case of the cleaning step, the cleaning liquid adhering to the surface of the work is washed off by rotating the work up, down, left or right in the tank 2b. Here, in this example,
Isopropanol is used as the alcohol solvent, and 12.2% by weight of this is mixed in water to form an azeotropic mixture. The boiling point of this azeotrope is 79.5 degrees.
Further, in this example, the specific gravity and the concentration of the aqueous solution are always controlled so that the aqueous solution is always in the state of an azeotropic mixture.

Next, the workpiece after being rinsed is dried in the next drying step 3. In this example, the work is steam dried. That is, in the tank 3a,
An aqueous solution 3b having the same components as the above aqueous solution is stored. The heater 3c is arranged so as to be immersed in this aqueous solution. The aqueous solution 3b is heated by the heater 3c to generate steam. The work is placed in this steam atmosphere,
The residual water adhering to the surface is dried and removed. Aqueous solution 3
The specific gravity and concentration of b are always controlled, and this aqueous solution is always kept in the state of an azeotropic mixture.

In the method of this example, the rinsing step 2
In, the work is immersed in the azeotropic mixture to apply the azeotropic mixture to the surface of the work. For this reason, the amount of water adhering to the surface of the work that moves to the drying step is reduced, and the surface tension of the adhering water is weakened. The boiling point of this azeotrope is lower than that of water.
Since it is 9.5 degrees, the work is dried quickly.
Thus, according to the method of this example, it is possible to dry the work in a short time. In this example, if the temperature of the azeotropic mixture is maintained in a state of being heated to a predetermined temperature, the work can be dried more quickly.

FIG. 2 shows another work cleaning method to which the present invention is applied. In this example, the cleaning step 10 is the first
And the second step 11 and 12. These first and second steps 11 and 12 include a storage tank 11b in which aqueous solutions 11a and 12a containing a surfactant are stored,
This is a step of immersing and cleaning a work (not shown) in 12b. Next, the rinsing step 20 is also composed of first and second steps 21 and 22. These steps are for tank 2
This is a step of immersing the work in pure water 21b, 22b stored in 1a, 22a to wash off the surfactant from the work.

The next step 30 is a step of applying a hydrophilic solvent to the surface of the work, and this step also includes first and second steps 31 and 32. In these steps, tank 31
The hydrophilic solvent is applied to the surface of the work by immersing the work in pure aqueous solutions 31b and 32b containing the hydrophilic solvent stored in a and 32a. The last step 40 is a drying step, in which the water adhering to the surface of the work is dried and removed by applying a physical force to the work. For example, water is dried and removed from the surface of the work by rotating the work at high speed or blowing air.

Also in the method of this example, the hydrophilic solvent is applied to the work in the step 30 preceding the drying step 40. Therefore, the water is removed from the surface of the work, the surface tension of the water attached to the surface of the work is reduced, and the water attached to the surface of the work is easily drained. Therefore, the work is sent to the drying step 40 with a small amount of residual water on the surface of the work, and the drying is completed in a short time in this drying step.
Further, similarly to the above-mentioned example, when an alcoholic solvent is used as the hydrophilic solvent, the drying of the adhered water on the surface of the work is promoted, so that the drying can be performed in a short time. Also in the method of this example, by controlling the mixing ratio of the hydrophilic solvent in the pure water stored in each tank 31a, 32a in step 30, the work can be dried more efficiently. is there.

The above two examples show examples of the present invention, and are not intended to limit the method of the present invention to these configurations. For example, it goes without saying that a solvent other than alcohol may be used as the hydrophilic solvent. Further, by immersing the work in an aqueous solution containing a hydrophilic solvent, the hydrophilic solvent is given to the work surface, but for example, an aqueous solution containing the hydrophilic solvent is applied to the work surface using a sprayer or the like. You may blow it. Furthermore, as the cleaning liquid to be used, a surfactant is used in the above example, but it goes without saying that the present invention can be applied to the case of using a cleaning liquid other than this.

[0019]

As described above, according to the method of the present invention, a hydrophilic solvent such as an alcohol solvent is mixed into the surface of a work in the rinsing step or before the drying step after the rinsing step. The applied aqueous solution is applied. Therefore, according to the method of the present invention, the water adhering to the work is eliminated by the hydrophilic solvent and the surface tension of the adhering water is reduced, so that the work can be dried quickly.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of a work cleaning method to which the present invention is applied.

FIG. 2 is an explanatory view showing an example of another work cleaning method to which the present invention is applied.

[Explanation of symbols]

1 ... Washing step 2 ... Rinse step 2a ... City water or pure water mixed with alcohol solvent 3 ... Drying step 10 ... Washing step 20 ... Rinse step 30 ... Hydrophilic solvent Application process 31b, 32b ... City water or pure water mixed with hydrophilic solvent 40 ... Drying process

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[Procedure amendment]

[Submission date] May 20, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 4

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

As the hydrophilic solvent, it is preferable to use an alcoholic solvent such as isopropanol.
Particularly, isopropanol containing 12.2% by weight of water is particularly preferable because it forms an azeotropic mixture.
Further, it is desirable to always control the mixing ratio of the hydrophilic solvent.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

In the next rinse step 2, the cleaned work is immersed in a storage tank 2b which stores a solution 2a of city water or pure water mixed with an alcohol solvent. As in the case of the cleaning step, the cleaning liquid adhering to the surface of the work is washed off by rotating the work up, down, left or right in the tank 2b. Here, in this example,
Isopropanol is used as the alcohol solvent, and 12.2% by weight of water is mixed therein to form an azeotropic mixture. The boiling point of this azeotrope is 79.5 degrees.
Further, in this example, the specific gravity and the concentration of the aqueous solution are always controlled so that the aqueous solution is always in the state of an azeotropic mixture.

[Procedure correction 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0019

[Correction method] Change

[Correction content]

[0019]

As described in the foregoing, in the method of the present invention, water in before moving to a drying step after passing through the rinsing step or a rinsing step, a hydrophilic solvent such as alcohol solvents on the workpiece surface An aqueous solution mixed with is added. Therefore, according to the method of the present invention, the water adhering to the work is eliminated by the hydrophilic solvent and the surface tension of the adhering water is reduced, so that the work can be dried quickly.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] Explanation of code

[Correction method] Change

[Correction content]

[Explanation of symbols] 1 ... Washing step 2 ... Rinse step 2a ... City water or pure water is mixed in alcohol solvent
Solvent 3 ... Drying process 10 ... Washing process 20 ... Rinse process 30 ... Hydrophilic solvent application process 31b, 32b ... Hydrophilic solvent mixed with city water or pure water
Filled solvent 40 ... Drying process

Claims (7)

[Claims] 1. A work cleaning device for cleaning and drying a work through a cleaning process for cleaning a work using a cleaning liquid, a rinse process for cleaning the cleaning liquid from the cleaned work, and a drying process for drying the work, At least one of the rinsing step and the step of shifting from the rinsing step to the drying step includes the step of applying an aqueous solution containing a hydrophilic solvent to the surface of the work. Characteristic work drying method. 2. The work drying method according to claim 1, wherein the hydrophilic solvent is an alcohol solvent. 3. The method for drying a work according to claim 2, wherein the aqueous solution is an azeotropic mixture. 4. The azeotropic mixture according to claim 3,
A method for drying a work, which is an aqueous solution containing 12.2% by weight of isopropanol. 5. The process according to claim 1, wherein the step of applying the aqueous solution mixed with the hydrophilic solvent to the work is a step of immersing the work in a tank of the aqueous solution. A method for drying a work characterized by: 6. The method according to claim 1, wherein the step of applying the aqueous solution mixed with the hydrophilic solvent to the work is a step of spraying the aqueous solution onto the work. Characteristic work drying method. 7. The method for drying a work according to claim 1, wherein the mixing amount of the hydrophilic solvent in the aqueous solution is controlled.