Detection control method for pollution degree of clamp

Abstract

The invention discloses a fixture pollution degree detection control method, which comprises the following steps: taking down a fixture from a cleaning basket, and washing with pure water; the cleaned clamp is put into pure water ultrasonic waves to be subjected to ultrasonic treatment, and the sound pressure intensity range of the ultrasonic waves is 0.1 mv to 0.2 mv; pure water waste liquid obtained after cleaning is sampled and subjected to bacterial culture in an incubator; the pollution condition of the clamp is judged according to the bacterial agglomeration number after culture; if it is judged that the clamps are polluted, the corresponding polluted clamps are subjected to soaking treatment or high-temperature baking treatment; and the treated clamp is washed, and cleanliness control is completed. According to the detection control method for the pollution degree of the clamp, whether the clamp is abnormal or not can be quantitatively confirmed, and a decision basis is provided for refined management.

Description

Technical Field

[0001] The invention relates to the technical field of cleanliness detection, and in particular to a method for detecting and controlling the contamination degree of a fixture. Background Art

[0002] During the production of photomask substrates, a layer of chromium film needs to be deposited on a clean glass substrate by magnetron sputtering or evaporation coating. The cleanliness of the glass substrate directly affects the light leakage of the coating pinholes and the density of the film layer. The most important purpose in the cleaning process is to deal with the particles on the glass surface, and the premise is that the tank and the components themselves are not polluted. In fact, during the operation of the equipment, the generation of particles is caused by many reasons, such as the pollution caused by the shedding of particles on the glass substrate that cannot be self-cleaned in time, the bacteria breeding on the wet parts of the equipment after shutdown, and the pollution caused by friction during the operation of the equipment. Generally, manual cleaning is required regularly. On the other hand, with the advancement of new technologies, online conductivity testers and particle testers are installed in the pure water rinsing part of the multi-tank connected cleaning equipment, which can monitor the conductivity and particle conditions of the rinsing tank at all times, and judge the residual or contamination of the tank body according to the size of the conductivity and the data of the particle test.

[0003] This method can monitor the pollution of the entire tank in a timely manner, but the pollution source cannot be determined, and the tank is relatively complex. Usually, the circulation and water inlet pipes, gas, tank inner wall, filter, cleaning basket and cleaning basket fixture are all potential pollution sources. The measures taken are mainly based on trial water change and sanitary treatment. If there is no online detection device, the judgment of specific slots can only be eliminated one by one through experiments. For example, let the cleaning basket-loaded film not pass through a certain tank body for experimental flow-out, and judge whether the tank is contaminated according to the product situation; similarly, the visual inspection method may not necessarily find a specific component, and the overall tank hygiene method is often used to try to restore it. Among these parts, the cleaning fixture is a common part: it carries the glass substrate together to experience the cleaning loading, cleaning, and unloading process, and is in direct contact with the glass substrate. Its pollution and degree of pollution are no less than the impact of pure water pollution on the product.

[0004] During the cleaning process, only two substances are in direct contact with the glass substrate throughout the whole process, one is pure water, and the other is the fixture. The importance of the fixture is self-evident. Other parts are not in direct contact with the glass, such as the tank, filter, etc., or are not in contact with the glass during the whole process, such as detergents. Among them, whether the pure water is contaminated or not is to ensure the supply quality through the power online monitoring of conductivity and other data, and to confirm its stability through data, which has sufficient reasons and good results; the stability of the fixture is to clean it regularly, and as for whether there are any problems, they are handled once, and generally there is no quantitative data. Therefore, how to finely judge whether the fixture is contaminated, and how to control and deal with it after it is contaminated, is a problem that needs to be solved at present. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the current fixture detection method, the present invention provides a detection and control method for the contamination degree of a fixture, which can quantitatively confirm whether the fixture is abnormal or not, and provide a decision-making basis for refined management.

[0006] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0007] A method for detecting and controlling the contamination degree of a fixture comprises the following steps:

[0008] Remove the fixture from the wash basket and rinse it with pure water;

[0009] The cleaned fixture is placed in a pure water ultrasonic wave for ultrasonic treatment, wherein the sound pressure intensity of the ultrasonic wave is in the range of 0.1-0.2mv;

[0010] Take samples of the pure water waste after cleaning and culture the bacteria in an incubator;

[0011] Obtain the number of bacterial aggregates;

[0012] The contamination of the fixture was determined based on the number of bacterial agglomerates after culture;

[0013] If the fixture is judged to be contaminated, the contaminated fixture is subjected to immersion treatment or high-temperature baking treatment;

[0014] Rinse the treated fixture to complete cleanliness control.

[0015] According to one aspect of the present invention, the clamps are classified into three categories: high temperature resistant, strong acid resistant, and weak acid resistant according to the materials of the clamps.

[0016] According to one aspect of the present invention, the material of the clamp is a high temperature resistant material, and the contaminated clamp is treated by high temperature baking.

[0017] According to one aspect of the present invention, the temperature of the high temperature baking is 140-200° C., and the time of the high temperature baking is 10-30 minutes.

[0018] According to one aspect of the present invention, the material of the clamp is a strong acid resistant material, and the contaminated clamp is immersed in 98% concentrated sulfuric acid.

[0019] According to one aspect of the present invention, the material of the fixture is a weak acid resistant material, and the contaminated fixture is immersed in 0.5%-1% hydrochloric acid or 30% hydrogen peroxide with pure water in a volume ratio of 1:2.

[0020] According to one aspect of the present invention, rinsing the treated fixture includes cleaning and scrubbing the treated fixture with IPA and rinsing it with pure water.

[0021] According to one aspect of the present invention, the sampling of the cleaned pure water waste liquid and culturing bacteria in an incubator comprises: sampling 200 ml of the cleaned pure water waste liquid and culturing bacteria in a constant temperature biochemical incubator at a temperature of 37° C. for 24 hours.

[0022] According to one aspect of the present invention, the soaking treatment time is 30 min-120 min.

[0023] Advantages of the present invention:

[0024] (1) The traditional particle monitoring method is online particle monitoring, that is, a particle detection probe is installed in the tank to be tested to test the conductivity of the tank. It determines the degree of contamination based on conductivity and other data. However, due to the large number of tank structural components (filter, spray pipe, tank, cleaning basket, product itself, basket cleaning fixture, etc.), it is impossible to determine where the contamination is, and no specific treatment method is provided; and this online method is only suitable for pure water tanks, because ultrasonic detergent tanks and acid-base tanks themselves have a large ion concentration, and it is impossible to determine the contamination through online conductivity detection. The present invention solves one of the problems, that is, the problem of the cleaning basket fixture. The degree of contamination of the fixture is determined by flushing, ultrasonicating, sampling and confirming the bacteria situation of the fixture, and then according to the acid and temperature resistance of the fixture, high temperature baking, strong acid immersion, weak acid immersion and other methods are used for sterilization and disinfection, and then IPA scrubbing and pure water flushing are performed to eliminate contamination.

[0025] (2) The present invention provides a targeted solution for refined decision-making. First, the solution can be used to determine whether the fixture is contaminated and the degree of contamination, instead of just treating all aspects of cleaning uniformly after the product is contaminated. In addition, the method has a quantitative comparison of the degree of fixture contamination, so the degree of contamination can be intuitively reflected based on the number of bacteria. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 The present invention is a flowchart of the method for detecting and controlling the degree of contamination of a fixture. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In the process of manufacturing photomask substrate, a chromium film needs to be plated on a clean glass substrate by magnetron sputtering or evaporation coating, and the cleaning before chromium film plating is an important link in the photomask substrate process. Whether the cleaning fixture is contaminated is an important factor affecting the cleanliness of the glass substrate, and it is easily neglected. Therefore, the present invention provides a method for detecting and controlling the cleanliness of the fixture during the cleaning process of high-precision glass substrates. The content of the present invention is described as follows:

[0031] like Figure 1 As shown, a method for detecting and controlling the contamination degree of a fixture comprises the following steps:

[0032] (1) Remove the fixture from the cleaning basket and rinse it briefly with pure water;

[0033] (2) placing the cleaned fixture into a pure water ultrasonic wave for ultrasonic treatment, wherein the ultrasonic sound pressure intensity ranges from 0.1 to 0.2 mv and the ultrasonic frequency ranges from 20 khz to 40 khz;

[0034] (3) Sampling 200 ml of the purified water waste after cleaning, and culturing bacteria in a constant temperature biochemical incubator at 37°C for 24 h;

[0035] (4) Obtaining the number of bacterial aggregates;

[0036] (5) Determine the contamination of the fixture based on the number of bacterial agglomerates after culture;

[0037] (6) If the fixture is determined to be contaminated, the contaminated fixture is subjected to immersion treatment or high-temperature baking treatment;

[0038] (7) Flushing the treated fixture, specifically including: using IPA cleaning and pure water to rinse the treated fixture to complete cleanliness control.

[0039] In practical applications, the clamps are classified into three categories according to the materials of the clamps: high temperature resistant, strong acid resistant, and weak acid resistant.

[0040] If the material of the fixture is a high temperature resistant material, the contaminated fixture is treated by high temperature baking. The temperature of the high temperature baking is 140-200°C and the time of the high temperature baking is 10-30 minutes.

[0041] If the material of the fixture is resistant to strong acid, the contaminated fixture shall be immersed in 98% concentrated sulfuric acid.

[0042] If the material of the fixture is resistant to weak acid, the contaminated fixture should be immersed in hydrochloric acid with a concentration of 0.5%-1% or in hydrogen peroxide with a concentration of 30% and pure water in a volume ratio of 1:2.

[0043] The time range of the above immersion treatment is 30min-120min.

[0044] Embodiment 1

[0045] Take the fixture on the cleaning basket that is in direct contact with the glass substrate. The fixture is made of SUS316L material, which is a high temperature resistant material, and conduct the experiment:

[0046] (1) Remove the SUS316L fixture from the cleaning basket and rinse it briefly with pure water;

[0047] (2) The cleaned SUS316L fixture was placed in a pure water ultrasonic bath for ultrasonic treatment at a frequency of 20 kHz, a sound pressure intensity of 0.15 mv, and an ultrasonic time of 10 min;

[0048] (3) taking 200 ml of the purified water waste liquid after cleaning as a sample, and culturing bacteria in a constant temperature biochemical incubator at 37° C. for 24 hours;

[0049] (4) Observe the number of bacterial clusters after culture. If the number of bacteria after culture is three clusters, it is confirmed that the fixture is contaminated with bacteria;

[0050] (5) The contaminated fixture is subjected to high-temperature baking sterilization treatment, the baking temperature is 180°C, the baking time is 20 minutes, and the oven is a Class 100 oven;

[0051] (6) The treated fixture is cleaned and scrubbed with IPA and rinsed with pure water to complete cleanliness control.

[0052] Experimental results comparison:

[0053] The fixtures before high-temperature baking and sterilization were subjected to the first product test to detect the particles on the fixture surface; the fixtures after high-temperature baking and sterilization were subjected to the second product test to detect the particles on the fixture surface. The comparison of the results of the first and second tests is shown in Table 1:

[0054]

[0055]

[0056] Table 1

[0057] The particle condition of the glass substrate is measured by a particle detection instrument, such as the Reflex 300TT particle detector produced by Nanophotonic; the bacterial condition is confirmed by visual inspection or metallographic microscope. From the data in Table 1, the method described in Example 1 does detect bacteria, and the growth of bacteria is well controlled by high-temperature baking, so that the particle condition of the product after cleaning is good and the quality is improved.

[0058] Embodiment 2

[0059] Take the fixture on the cleaning basket that is in direct contact with the glass substrate. The fixture is made of quartz material, which is resistant to high temperature and strong acid, and conduct the experiment:

[0060] (1) Remove the quartz fixture from the cleaning basket and rinse it briefly with pure water;

[0061] (2) placing the cleaned quartz fixture in pure water ultrasonic wave for ultrasonic treatment, with an ultrasonic frequency of 40 kHz, a sound pressure intensity of 0.15 mV, and an ultrasonic time of 10 min;

[0062] (3) taking 200 ml of the purified water waste liquid after cleaning as a sample, and culturing bacteria in a constant temperature biochemical incubator at 37° C. for 24 hours;

[0063] (4) Observe the number of bacterial aggregates after culture. If the number of bacteria after culture is two aggregates, it is confirmed that the fixture is contaminated with bacteria;

[0064] (5) The contaminated fixture is sterilized by immersion in concentrated sulfuric acid, wherein the concentration of the concentrated sulfuric acid is 98%, the temperature is 90°C, and the immersion time is 40 minutes;

[0065] (6) Rinse the treated fixture with pure water, wipe it with IPA, and then rinse it with pure water to complete the cleanliness control.

[0066] Experimental results comparison:

[0067] The fixtures before soaking in concentrated sulfuric acid were subjected to the first product test to detect the particles on the fixture surface; the fixtures after soaking in concentrated sulfuric acid were subjected to the second product test to detect the particles on the fixture surface. The comparison of the results of the first and second tests is shown in Table 2:

[0068]

[0069]

[0070] Table 2

[0071] The particle condition of the glass substrate is measured by a particle detection instrument; the bacterial condition is confirmed by visual inspection or metallographic microscope. From the data in Table 2, the method described in Example 2 does detect bacteria, and the bacterial growth is well controlled by soaking in concentrated sulfuric acid, so that the particle condition of the product after cleaning is good and the quality is improved.

[0072] Embodiment 3

[0073] Take the fixture on the cleaning basket that is in direct contact with the glass substrate. The fixture is made of PTFE material, which is resistant to high temperature and weak acid. Conduct the experiment:

[0074] (1) Remove the PTFE fixture from the cleaning basket and rinse it briefly with pure water;

[0075] (2) placing the cleaned PTFE fixture in pure water ultrasonic wave for ultrasonic treatment, with the ultrasonic frequency of 40 kHz, the sound pressure intensity of 0.05 mv, and the ultrasonic time of 10 min;

[0076] (3) Take 200 ml of the pure water waste liquid after cleaning as a sample and culture bacteria in a constant temperature biochemical incubator at 37°C for 24 hours; (first bacterial culture)

[0077] (4) Observe the number of bacterial aggregates after culture to ensure there is no bacterial contamination. Adjust the intensity of ultrasound and perform bacterial culture again.

[0078] (5) Rinse the PTFE fixture in step 1 again with pure water;

[0079] (6) The cleaned PTFE fixture was placed in a pure water ultrasonic wave for ultrasonic treatment at an ultrasonic frequency of 40 kHz, a sound pressure intensity of 0.2 mV, and an ultrasonic time of 10 min;

[0080] (7) Sampling 200 ml of the purified water waste liquid after the second cleaning as a sample, and carrying out bacterial culture in a constant temperature biochemical incubator at a temperature of 37° C. for 24 hours; (second bacterial culture)

[0081] (8) Observe the number of bacterial clusters after re-cultivation. The number of bacteria after culturing is three clusters, confirming that the fixture is contaminated with bacteria;

[0082] (9) The contaminated fixture is sterilized by immersion in hydrochloric acid, wherein the concentration of the hydrochloric acid is 0.8%, the temperature is normal, and the immersion time is 40 minutes;

[0083] (10) The treated fixture is cleaned and scrubbed with IPA and rinsed with pure water to complete cleanliness control.

[0084] Experimental results comparison:

[0085] The fixture before the first bacterial culture was subjected to the first product test to detect the particles on the fixture surface; the fixture before the second bacterial culture was subjected to the second product test to detect the particles on the fixture surface; the fixture after soaking in hydrochloric acid was subjected to the third product test to detect the particles on the fixture surface. The comparison of the results of the first, second and third tests is shown in Table 3:

[0086]

[0087] Table 3

[0088] The particle situation of the glass substrate is measured by a particle detection instrument; the bacterial situation is confirmed by visual inspection or metallographic microscope. From the data of Example 3: 1. The sound pressure intensity has an impact on the sampled sample. When the sound pressure intensity is 0.05mv, it is impossible to complete the bacterial culture by sampling. Under the same conditions, when the ultrasound is 0.18mv, agglomerated bacterial clusters can be cultured, indicating that the sound pressure intensity is also a key influencing factor in this detection and control process. The principle is that when the ultrasound is low, the bacteria and particles cannot fall off from the fixture into the sample, and bacterial clusters cannot be formed after cultivation. 2. The hydrochloric acid immersion sterilization method can achieve a sterilization effect. 3. A large number of experiments have shown that it is appropriate to control the sound pressure intensity at 0.1-0.2mv. When it is lower than 0.1mv, the bacteria cannot fall off in the sample, affecting the sampling effect; if the sound pressure intensity is too high, some bacteria will be killed by ultrasound, affecting the bacterial situation of the sample to be sampled.

[0089] Embodiment 4

[0090] Take the fixture on the cleaning basket that is in direct contact with the glass substrate. The fixture is made of PVDF material, which is resistant to high temperature and weak acid. Conduct the experiment:

[0091] (1) Remove the PVDF fixture from the cleaning basket and rinse it briefly with pure water;

[0092] (2) The cleaned PVFD fixture was placed in pure water ultrasound for ultrasonic treatment at an ultrasonic frequency of 40 khz, a sound pressure intensity of 0.16 mv, and an ultrasonic time of 10 min;

[0093] (3) taking 200 ml of the purified water waste liquid after cleaning as a sample, and culturing bacteria in a constant temperature biochemical incubator at 37° C. for 24 hours;

[0094] (4) Observe the number of bacterial clusters after culture. If the number of bacteria after culture is three clusters, it is confirmed that the fixture is contaminated with bacteria;

[0095] (5) The contaminated fixture is subjected to a sterilization soaking treatment, wherein the soaking liquid is a solution of hydrogen peroxide and pure water mixed in a volume ratio of 1:2, the hydrogen peroxide concentration is 30%, the temperature is normal, and the soaking time is 40 minutes;

[0096] (6) The treated fixture is cleaned and scrubbed with IPA, and then rinsed with pure water to complete cleanliness control.

[0097] Experimental results comparison:

[0098] The fixtures before being soaked in the hydrogen peroxide mixed solution were subjected to the first product test to detect the particles on the fixture surface; the fixtures after being soaked in the hydrogen peroxide mixed solution were subjected to the second product test to detect the particles on the fixture surface. The results of the first and second tests are compared.

[0099] As shown in Table 4:

[0100]

[0101]

[0102] Table 4

[0103] The particle condition of the glass substrate is measured by a particle detection instrument; the bacterial condition is confirmed by visual inspection or metallographic microscope. From the data in Table 4, the method described in Example 4 does detect bacteria, and the growth of bacteria is well controlled by immersion in a hydrogen peroxide mixed solution, so that the particle condition of the product after cleaning is good and the quality is improved.

[0104] The traditional particle monitoring method is online particle monitoring, that is, a particle detection probe is installed in the tank to be tested to test the conductivity of the tank, and the degree of contamination is determined based on conductivity and other data. However, due to the large number of tank structural components (filter, spray pipe, tank, cleaning basket, product itself, basket washing fixture, etc.), it is impossible to determine where the contamination is, and no specific treatment method is provided; and this online method is only suitable for pure water tanks, because ultrasonic detergent tanks and acid-base tanks themselves have a large ion concentration, and it is impossible to determine the contamination through online conductivity detection. The present invention solves one of the problems, that is, the problem of the cleaning basket fixture, by flushing the fixture, ultrasonic, sampling to confirm the bacteria situation to determine the degree of contamination of the fixture, and then according to the acid and temperature resistance of the fixture, high temperature baking, strong acid immersion, weak acid immersion and other methods are used for sterilization and disinfection, and then IPA scrubbing and pure water flushing are performed to eliminate contamination.

[0105] The present invention provides a targeted solution for refined decision-making. First, the solution can be used to determine whether the fixture is contaminated and the degree of contamination, instead of just uniformly treating all aspects of cleaning as a whole after the product is contaminated. Moreover, the method has a quantitative comparison of the degree of fixture contamination, so the degree of contamination can be intuitively reflected based on the number of bacteria.

[0106] At the same time, this method provides some ideas for the contamination of other components (such as filter contamination). This solution is not limited to the detection and control of the degree of contamination of the fixture. Similar confirmatory attempts can also be made on filters, spray pipes, tanks, cleaning baskets, products themselves, etc.

[0107] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the art within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for detecting and controlling the contamination degree of a fixture, characterized in that: The following steps are involved: Remove the fixture from the wash basket and rinse it with pure water; The cleaned fixture is placed in a pure water ultrasonic bath for ultrasonic treatment; Take samples of the pure water waste after cleaning and culture the bacteria in an incubator; Obtain the number of bacterial aggregates; The contamination of the fixture was determined based on the number of bacterial agglomerates after culture; If the fixture is judged to be contaminated, the contaminated fixture is subjected to immersion treatment or high-temperature baking treatment; Rinse the treated fixture to complete cleanliness control.

2. The method for detecting and controlling the degree of fixture contamination according to claim 1, characterized in that: The sound pressure intensity of the ultrasonic wave is in the range of 0.1-0.2mv.

3. The method for detecting and controlling the degree of fixture contamination according to claim 1, characterized in that: The clamps are classified into three categories according to the materials of the clamps: high temperature resistant, strong acid resistant, and weak acid resistant.

4. The method for detecting and controlling the degree of fixture contamination according to claim 3, characterized in that: If the material of the clamp is a high temperature resistant material, the contaminated clamp is treated by high temperature baking.

5. The method for detecting and controlling the degree of fixture contamination according to claim 4, characterized in that: The temperature of the high temperature baking is 140-200° C., and the time of the high temperature baking is 10-30 minutes.

6. The method for detecting and controlling the degree of fixture contamination according to claim 3, characterized in that: If the material of the fixture is a strong acid-resistant material, the contaminated fixture is immersed in 98% concentrated sulfuric acid.

7. The method for detecting and controlling the degree of fixture contamination according to claim 3, characterized in that: If the material of the fixture is a weak acid resistant material, the contaminated fixture is soaked in hydrochloric acid with a concentration of 0.5%-1% or in hydrogen peroxide with a concentration of 30% and pure water in a volume ratio of 1:

2.

8. The method for detecting and controlling the degree of fixture contamination according to claim 1, characterized in that: The rinsing of the treated fixture includes cleaning and scrubbing the treated fixture with IPA and rinsing with pure water.

9. The method for detecting and controlling the degree of fixture contamination according to claim 1, characterized in that: The method of sampling the cleaned pure water waste liquid and culturing bacteria in an incubator comprises: sampling 200 ml of the cleaned pure water waste liquid and culturing bacteria in a constant temperature biochemical incubator at a temperature of 37° C. for 24 hours.

10. The method for detecting and controlling the degree of fixture contamination according to claim 1, characterized in that: The soaking time is 30 min-120 min.

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