JPH0568951A - Cleaning process - Google Patents

Abstract

PURPOSE:To carry out cleaning without leaving stain dispensing with a fleon- type solvent by carrying out a two-step degreasing step to degrease a material to be cleaned by a non-aqueous solution and an aqueous solvent, a finishing cleaning step, a rinsing step and a drying process using a plurality of highly pure water layers. CONSTITUTION:A cleaning apparatus consists of four degreasing tanks 1-4 to clean a material to be cleaned with a non-aqueous liquid after processing step and two cleaning tanks 5-6 to clean out non-aqueous liquid. Further, there are installed a rinsing tank 7 to clean the material to be cleaned with general water, cleaning tanks 8-9 to carry out finishing cleaning of the material to be cleaned, rinsing tank 10-11 to clean the material to be cleaned with pure water, hot pure water tanks 12-13 to immerse the material to be cleaned in humidified superpure water, and a hot air zone 14 as a drying tank to dry the material to be cleaned. The hot pure water tank 13 is used as a pulling out tank in which the pure water is heated at about 70-80 deg.C and the surface of the material to be cleaned is dried by pulling it up out of the hot pure water at about 3-8mm/sec.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning parts or products, and more particularly to a method for cleaning optical parts.

[0002]

2. Description of the Related Art Conventionally, cleaning of machine parts and optical parts after processing is carried out, for example, by the steps shown in FIG.

The cleaning process will be described below.

Step a: The pitch adhering to the surface of the member to be cleaned (not shown) is removed with a non-aqueous solvent.

The member to be cleaned is sequentially dipped from the first degreasing liquid 1 to the fourth degreasing liquid 4 by a transport mechanism (not shown) and pulled up. Each of these four liquids is perchlorethylene. The temperature of each liquid is room temperature.

Step b: The non-aqueous liquid covering the surface of the member to be cleaned is replaced with an aqueous liquid. That is, it is immersed in the first replacement liquid 5 and the second replacement liquid 6 and pulled up.

The first replacement liquid 5 and the second replacement liquid 6 are aqueous solutions containing a surfactant. The temperature of each liquid is room temperature.

Step c: Finish cleaning is performed.

The first finish cleaning liquid to the third finish cleaning liquid are dipped and pulled up.

The first finish cleaning liquid 7 uses city water (tap water).

The second finishing cleaning liquid 8 is an anionic or nonionic surfactant.

The third finishing cleaning liquid 9 is the same as the cleaning liquid 8.

Step d: Rinse is performed.

First rinse liquid 10 and second rinse liquid 12
Immerse in and pull up.

Both the first and second rinse liquids are city water.

Step e: The non-aqueous solvent is immersed in the first and second substitution liquids 12 and 13 and is pulled up.

Both the first and second replacement liquids are IPA (isopropyl alcohol).

Step f: The IPA attached to the member to be cleaned is dried.

The member to be cleaned is allowed to stay in the CFC vapor 14 generated by heating the CFC liquid with a heater (not shown) for a predetermined time and then pulled up.

[0020]

In the above-mentioned conventional method, a chlorofluorocarbon solvent is indispensable. However, due to an increasing demand for environmental protection in recent years, a chlorofluorocarbon-free cleaning is required as in various other fields. ing. A particular problem with cleaning methods other than CFCs is so-called stain residue, which occurs in the drying step after wet cleaning.

[0021] The present invention provides a method for cleaning a part or a product, which does not use a CFC-based solvent and is free from stain residue.

[0022]

A method of cleaning a member to be cleaned such as a part or a product according to the present invention comprises a first degreasing step of degreasing the member to be cleaned which has undergone a processing step with a non-aqueous liquid, A cleaning method, comprising: a second degreasing step of degreasing the member to be cleaned with an aqueous solution that dissolves an aqueous solution; a finish cleaning step with the aqueous solution; a rinse step; and a drying step. Is to dry the surface of the member to be cleaned by providing a plurality of pure water tanks, setting the temperature of the last pure water tank to a temperature range of 70 to 85 ° C., and pulling up the member to be cleaned from the pure water tank. Is characterized by.

Further, the pure water in the plurality of pure water tanks has a temperature gradient in the order of the cleaning process.

Further, it is characterized in that the speed for pulling up the part to be cleaned from the last pure water tank is set to be inversely proportional to the surface area of the material to be cleaned.

[0025]

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

FIG. 2 is an explanatory view schematically showing an embodiment of the apparatus for cleaning an object to be cleaned according to the present invention.

In this embodiment, four degreasing tanks 1, 2, 3 and 4 for cleaning an object to be cleaned with a non-aqueous liquid, two cleaning tanks 5 and 6 for cleaning a non-aqueous liquid and an object to be cleaned. A rinse tank 7 for cleaning the cleaning object with general water, cleaning tanks 8, 9 for finishing cleaning the cleaning object, a rinsing tank 10 for cleaning the cleaning object with pure water,
11, hot pure water tanks 12 and 13 for immersing the object to be cleaned in heated ultrapure water, and a warm air zone 14 as a drying tank for drying the object to be cleaned.

Next, the cleaning method according to this embodiment will be described.

First, the object to be cleaned (for example, the optical glass which has been subjected to the known polishing process) is immersed in the degreasing tanks 1, 2, 3 and 4 filled with an organic solvent such as perchlorethylene or the like. Pitch, oil, etc. adhering to is degreased.

The object to be cleaned after the step a is immersed in the cleaning tanks 5 and 6 filled with the surfactant, and then the step b is performed.

The object to be cleaned which has undergone the steps a and b is dipped in the cleaning tank 7 filled with general water and further immersed in the cleaning tanks 8 and 9 filled with the surfactant c step. Through the final cleaning process. Then, it is immersed in the rinse tanks 9 and 10 of the step d filled with pure water to go through the rinse step.

The object to be cleaned that has undergone the steps from a to d is e
The process goes through the warm pure water immersion process. It is soaked in an ultrapure water tank 12 filled with ultrapure water (having a resistivity of about 10 MΩ · cm or more) that has been purified by an ultrapure water production apparatus described later and heated to about 40 ° C. by a heater (not shown). A hot pure water immersion process is performed. Next, the object to be cleaned goes through the pulling up step of the step f. The pull-up tank 13 is filled with ultrapure water of the same quality as the ultrapure water filled in the ultrapure water tank 12 except that it is heated to about 70 ° C. to 85 ° C. by a heater (not shown). There is. The item to be cleaned is 3 to 10 from the pulling tank 13.
mm / sec. It is pulled up from the pulling tank 13 at a pulling rate of. The object to be cleaned that has been pulled up is heated to about 60 ° C. by a heater (not shown) and
A drying step g using warm air purified by a filter (dust collecting filter) is performed. This drying step using warm air does not need to shorten the drying time.

The results shown in Table 1 were obtained between the pulling rate from the pulling tank 13 and the surface area of the object to be cleaned.

Through the above steps, the degree of cleaning when the glass lens was cleaned was measured.

The material of the lens used is BK7, SF6, L
The measuring method, which is ak8 and is after the polishing step, was visually performed under a focusing lamp.

[0036]

[Table 1]

(Comparative Example) In Comparative Example 1 which is the same as the Example except that the temperature of the ultrapure water in the ultrapure water tank 12 was room temperature, cleaning stains were generated on the object to be cleaned in any case. ..

(Comparative Example 2) In Comparative Example 2 which is the same as the Example, except that both the ultrapure water in the ultrapure water tank 12 and the ultrapure water in the pulling tank 13 are ordinary water. In all cases, cleaning stains occurred.

[0039]

As described above, according to the present invention, a plurality of pure water tanks are provided in the drying process of parts or products, and the temperature of the last pure water tank is set in the temperature range of 70 to 85 ° C. By pulling up the member to be cleaned and drying the surface of the member to be cleaned, it becomes possible to perform cleaning without stain residue.

[Brief description of drawings]

FIG. 1 is an explanatory view schematically showing a cleaning method according to the present invention.

FIG. 2 is an explanatory diagram schematically showing a cleaning method according to a conventional example.

[Explanation of symbols]

 1 Pitch removal organic solvent 2 Pitch removal organic solvent 3 Pitch removal organic solvent 4 Pitch removal organic solvent 5 Surfactant 6 Surfactant 7 Rinse water 8 Finishing surfactant 9 Finishing surfactant 10 Rinse water 11 Rinse City water 12 Hot pure water 13 Hot pure water raising 14 Hot air zone 201 Pitch removing organic solvent 202 Pitch removing organic solvent 203 Pitch removing organic solvent 204 Pitch removing organic solvent 205 Surfactant 206 Surfactant 2077 Rinse city water 208 Finishing surfactant 209 Finishing Surfactant 210 City Water for Rinse 211 City Water for Rinse 212 IPA 213 IPA 214 CFC Vapor

Front Page Continuation (72) Inventor Satoshi Nishiguchi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (5)

[Claims] 1. A method for cleaning a member to be cleaned such as a part or a product, which comprises a first degreasing step of degreasing the member to be cleaned that has undergone a processing step with a non-aqueous liquid, and an aqueous solvent that dissolves the non-aqueous liquid. A cleaning method comprising: a second degreasing step of degreasing the member to be cleaned with; a final cleaning step with the aqueous liquid; a rinse step; and a drying step, wherein the drying step is performed from a plurality of pure water tanks. And the temperature of the last pure water tank is 70
A cleaning method, characterized in that the surface of the member to be cleaned is dried by setting the temperature range to 85 ° C. and pulling up the member to be cleaned from the last pure water tank. 2. The cleaning method according to claim 1, wherein the pure water in the plurality of pure water tanks has a temperature gradient in the order of the cleaning steps. 3. The cleaning method according to claim 1, wherein the speed of pulling up the member to be cleaned from the last pure water tank is set to be inversely proportional to the surface area of the material to be cleaned. 4. When the surface area of the member to be cleaned is 20 to 5000 mm ² , the pulling rate is 3 to 8 mm /
sec. A cleaning method characterized by being set to. 5. The cleaning method according to claim 1, wherein the material to be cleaned is a glass material.