Wet cleaning process for inner cavity pipeline of sliding diaphragm type electromagnetic valve

Abstract

The invention relates to the technical field of semiconductors. The invention discloses a wet cleaning process for an inner cavity pipeline of a sliding diaphragm type electromagnetic valve. The wet cleaning process comprises the following steps: step 1, soaking in isopropanol; external voltage is applied to the part, an injector is used for sucking a proper amount of isopropanol solution, the isopropanol solution is injected from a liquid inlet of the part at a certain speed, continuous flushing is carried out for 1-5 min, a power source is cut off, the liquid medicine is kept full, and standing is carried out for 15-30 min; step 2, soaking with ammonia water and hydrogen peroxide; step 3, soaking with hydrochloric acid and hydrogen peroxide; step 4, soaking with nitric acid; step 5, washing with pure water; step 6, nitrogen purging; and external voltage is applied to the part, a nitrogen pipe is connected, continuous purging is carried out for 1-5 min, and then dust-free packaging is carried out.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cleaning, in particular to a cleaning method for an inner cavity pipeline of a solenoid valve. BACKGROUND

[0002] The valve series made of fluororesin is widely used in small flow liquid control small series array, wherein the solenoid valve is a small solenoid coil and fluororesin technology combined with high pilot reliability by using air pressure, and under the condition of no pilot air source, the solenoid coil can be used to simply and conveniently control the liquid flow. The inner cavity pipeline is usually made of PTFE and PFA materials. In recent years, the solenoid valve, especially the fluororesin solenoid valve, is more and more widely used in the ultra-clean field of semiconductors, and higher requirements for the cleanliness of the inner cavity pipeline are put forward.

[0003] At present, the cleaning of the solenoid valve is mainly aimed at the external surface, and there is no solution to the problem of long-term precipitation of metal ions in the inner cavity pipeline.

[0004] Therefore, it is of great significance to develop a new type of wet cleaning process with high cleaning degree and simple procedure to improve the problem of ion precipitation in the inner cavity pipeline of the solenoid valve. SUMMARY

[0005] In view of the problems existing in the prior art, the present application provides a wet cleaning process for the inner cavity pipeline of a sliding diaphragm type solenoid valve to solve at least one of the above technical problems.

[0006] In order to achieve the above purpose, the present application provides a wet cleaning process for the inner cavity pipeline of a sliding diaphragm type solenoid valve, characterized in that it comprises the following steps:

[0007] Step 1: isopropanol soaking;

[0008] An external voltage is applied to the component, an appropriate amount of isopropanol solution is sucked by a syringe, and is injected from the liquid inlet of the component at a certain speed, and the flushing is continued for 1-5 min, the power is cut off, the liquid is kept full, and the component is kept standing for 15-30 min;

[0009] Step 2: ammonia water and hydrogen peroxide soaking;

[0010] An external voltage is applied to the component, an appropriate amount of pure water is sucked by a syringe to flush the pipeline, and an appropriate amount of ammonia water and hydrogen peroxide solution is sucked, and is injected from the liquid inlet of the component at a certain speed, and the flushing is continued for 1-5 min, the power is cut off, the liquid is kept full, and the component is kept standing for 30-60 min;

[0011] Step 3: hydrochloric acid and hydrogen peroxide soaking;

[0012] Applying external voltage to the component, using a syringe to suck a certain amount of pure water to flush the pipeline, then sucking a certain amount of hydrogen peroxide solution, injecting from the liquid inlet of the component at a certain speed, continuously flushing for 1-5 min, cutting off the power supply, keeping the medicine water full, standing for 30-60 min;

[0013] Step four, nitric acid soaking;

[0014] Applying external voltage to the component, using a syringe to suck a certain amount of pure water to flush the pipeline, then sucking a certain amount of hydrogen peroxide solution, injecting from the liquid inlet of the component at a certain speed, continuously flushing for 1-5 min, cutting off the power supply, keeping the medicine water full, standing for 30-60 min;

[0015] Step five, pure water flushing;

[0016] Applying external voltage to the component, using a syringe to suck a certain amount of pure water to flush the pipeline, continuously flushing for 1-5 min, cutting off the power supply;

[0017] Step six, nitrogen blowing;

[0018] Applying external voltage to the component, connecting the nitrogen tube, continuously blowing for 1-5 min, and then carrying out dust-free packaging.

[0019] Further preferably, in step one, step two, step three, step four and step five, the applied external power supply is the standard voltage required by the electromagnetic valve model. Preferably, it is one or more of DC12V and DC24V.

[0020] Further preferably, in step one, step two, step three, step four and step five, the syringe is made of high-purity plastic.

[0021] Further preferably, the material of the syringe is PP or PFA.

[0022] Further preferably, in step one, the isopropyl alcohol solution is one or more of G2, G3, G4, G5, etc.

[0023] Further preferably, in step one, the syringe injects the component from the liquid inlet of the component at a speed of 1-5 ml / min. Preferably, it is one or more of 2 ml / min, 3 ml / min, and 4 ml / min.

[0024] Further preferably, in step one, the continuous flushing time is preferably 2 min, 3 min or 4 min.

[0025] Further preferably, in step one, the single control opening time of the component is 1-5 min.

[0026] It is required to turn off the power supply in a certain time to protect the sliding film of the electromagnetic valve, and the single control opening time is.

[0027] Further preferably, the volume ratio of ammonia water, hydrogen peroxide and water in the ammonia water hydrogen peroxide solution is 1:1:2-5. The volume ratio of ammonia water, hydrogen peroxide and water in the ammonia water hydrogen peroxide solution is 1:1:2, 1:1:3 or 1:1:5.

[0028] Further preferably, the volume ratio of hydrochloric acid, hydrogen peroxide and water in the hydrochloric acid hydrogen peroxide solution is 1:1:4-6. The volume ratio of hydrochloric acid, hydrogen peroxide and water in the hydrochloric acid hydrogen peroxide solution is 1:1:4, 1:1:5 or 1:1:6.

[0029] Further preferably, the nitric acid solution is 2-10% volume percentage concentration of nitric acid. Preferably, one or more of 2%, 5% and 10% volume percentage concentration.

[0030] Further preferably, the nitrogen gas has a purity of 99.5-99.9%.

[0031] The present application discloses a cleaning method for the inner cavity of an electromagnetic valve for delivering corrosive acidic liquid in the semiconductor industry. The cleanliness requirement is high. The inner cavity of the sliding diaphragm type electromagnetic valve is a PTFE component.

[0032] Compared with the prior art, the present application has the following beneficial effects:

[0033] By the method of chemical cleaning, the metal precipitation of the PTFE component in the inner cavity of the electromagnetic valve in the acidic environment can be effectively reduced, the metal ion precipitation condition is improved, the cleanliness of the inner cavity pipeline of the electromagnetic valve is improved, the impurity precipitation of the component is reduced, and the customer's on-machine demand is realized. The operation is simple, the cost is low, and it is suitable for popularization and use. DETAILED DESCRIPTION

[0034] The present application will be further described below.

[0035] Specific embodiment 1: a wet cleaning process for the inner cavity pipeline of a sliding diaphragm type electromagnetic valve, comprising the following steps:

[0036] Step one, isopropanol soaking;

[0037] An external voltage is applied to the component, an appropriate amount of isopropanol solution is sucked by a syringe, and is injected from the liquid inlet of the component at a speed of 25ml / L, and the flushing is continued for 2min, the power is cut off, the medicine is kept full, and the component is placed for 30min;

[0038] Step two, ammonia water hydrogen peroxide soaking;

[0039] An external voltage is applied to the component, an appropriate amount of pure water is sucked by a syringe to flush the pipeline, and an appropriate amount of ammonia water hydrogen peroxide solution is sucked, and is injected from the liquid inlet of the component at a speed of 25ml / L, and the flushing is continued for 2min, the power is cut off, the medicine is kept full, and the component is placed for 30min;

[0040] Step three, hydrochloric acid hydrogen peroxide soaking;

[0041] The external voltage is applied to the component, a syringe is used to suck a proper amount of pure water to flush the pipeline, then a proper amount of hydrochloric acid hydrogen peroxide solution is sucked, and the solution is injected from the liquid inlet of the component at a speed of 25ml / L, the flushing is continued for 2 minutes, the power is cut off, the drug solution is kept full, and the component is kept for 30 minutes;

[0042] Step four, nitric acid soaking;

[0043] The external voltage is applied to the component, a syringe is used to suck a proper amount of pure water to flush the pipeline, then a proper amount of nitric acid solution is sucked, and the solution is injected from the liquid inlet of the component at a speed of 25ml / L, the flushing is continued for 2 minutes, the power is cut off, the drug solution is kept full, and the component is kept for 6 hours;

[0044] Step five, pure water flushing;

[0045] The external voltage is applied to the component, a syringe is used to suck a proper amount of pure water to flush the pipeline, and the flushing is continued for 2 minutes, and the power is cut off;

[0046] Step six, nitrogen blowing;

[0047] The external voltage is applied to the component, a nitrogen pipe is connected, and the blowing is continued for 2 minutes, and the power is cut off. Then, dust-free packaging is carried out.

[0048] When the external voltage is applied to the sliding diaphragm type electromagnetic valve, the valve is opened. When the power is cut off, the valve is closed.

[0049] The results after cleaning are as follows:

[0050]

[0051] The design idea of the application is as follows:

[0052] First, organic matter cleaning is carried out. The purpose of this step is to remove the organic dirt, machining oil dirt and other substances attached to the inner cavity PTFE pipeline during processing or transportation. According to the principle of similar solubility between organic matters, most of the organic matters are dissolved by isopropyl alcohol, and the remaining metal impurities wrapped by the organic matters are exposed, which are used as pretreatment for subsequent metal removal.

[0053] Second, ammonia hydrogen peroxide soaking cleaning. Since the Al element is high before washing and there is a relatively strict standard for Al, an alkaline reagent needs to be used for cleaning, and the temperature is increased to accelerate the leaching rate of Al element. After cleaning, the component is flushed with deionized water to remove residual drug solution.

[0054] Third, hydrochloric acid hydrogen peroxide soaking cleaning. The remaining metal impurities such as Fe, Zn, Ni and Cu in the raw material are removed. After washing, the component is flushed with deionized water.

[0055] Then nitric acid soak. Nitric acid can further remove common metal impurities.

[0056] Finally, rinse with pure water and dry with nitrogen.

[0057] The above is only the preferred embodiment of the present application, it should be noted that for those skilled in the art, without departing from the principles of the present application, can also make a number of improvements and refinements, these improvements and refinements should also be considered within the scope of the present application.

Claims

1. A wet cleaning process for the internal tubing of a sliding diaphragm solenoid valve, characterized in that, Includes the following steps: Step 1: Soak in isopropanol; Apply an external voltage to the component, use a syringe to draw an appropriate amount of isopropanol solution, inject it into the component's inlet at a certain speed, continue rinsing for 1-5 minutes, cut off the power, keep the solution full, and let stand for 15-30 minutes. Step 2: Soak in ammonia and hydrogen peroxide; Apply an external voltage to the component, use a syringe to draw an appropriate amount of pure water to flush the pipeline, then draw an appropriate amount of ammonia and hydrogen peroxide solution and inject it into the component inlet at a certain speed, continue flushing for 1 to 5 minutes, cut off the power, keep the solution full, and let it stand for 30 to 60 minutes. Step 3: Soak in hydrochloric acid and hydrogen peroxide; Apply an external voltage to the component, use a syringe to draw an appropriate amount of pure water to flush the pipeline, then draw an appropriate amount of hydrochloric acid hydrogen peroxide solution and inject it into the component inlet at a certain speed, continue flushing for 1 to 5 minutes, cut off the power, keep the solution full, and let it stand for 30 to 60 minutes. Step four: Soak in nitric acid; Apply an external voltage to the component, use a syringe to draw an appropriate amount of pure water to flush the pipeline, then draw an appropriate amount of nitric acid solution and inject it into the component inlet at a certain speed, continue flushing for 1 to 5 minutes, cut off the power, keep the solution full, and let it stand for 3 to 6 hours. Step 5: Rinse with pure water; Apply an external voltage to the component, use a syringe to draw an appropriate amount of pure water to flush the pipeline, continue flushing for 1-5 minutes, and then disconnect the power supply. Step six: Nitrogen purging; Apply an external voltage to the component, connect a nitrogen tube, and purge continuously for 1-5 minutes, followed by dust-free packaging.

2. The wet cleaning process for the inner cavity pipeline of a sliding diaphragm solenoid valve according to claim 1, characterized in that: In steps one, two, three, four, and five, the external power supply applied is the standard voltage required by the solenoid valve model.

3. The wet cleaning process for the inner cavity pipeline of a sliding diaphragm solenoid valve according to claim 1, characterized in that: In steps one, two, three, four, and five, the syringe is made of high-purity plastic.

4. The wet cleaning process for the inner cavity pipeline of a sliding diaphragm solenoid valve according to claim 1, characterized in that: In step one, the isopropanol solution is one or more of grades G2, G3, G4, and G5.

5. The wet cleaning process for the inner cavity pipeline of a sliding diaphragm solenoid valve according to claim 1, characterized in that: In step one, the syringe injects liquid into the component at a rate of 1-5 ml / min through the component inlet.

6. The wet cleaning process for the inner cavity pipeline of a sliding diaphragm solenoid valve according to claim 1, characterized in that: In step one, the preferred rinsing time is 2 minutes, 3 minutes, or 4 minutes.

7. The wet cleaning process for the inner cavity pipeline of a sliding diaphragm solenoid valve according to claim 1, characterized in that: In step one, the single control activation time for the component is 1 to 5 minutes.

8. The wet cleaning process for the inner cavity pipeline of a sliding diaphragm solenoid valve according to claim 1, characterized in that: The volume ratio of ammonia, hydrogen peroxide, and water in the ammonia-hydrogen peroxide solution is 1:1:2~5.

9. The wet cleaning process for the inner cavity pipeline of a sliding diaphragm solenoid valve according to claim 1, characterized in that: The volume ratio of hydrochloric acid, hydrogen peroxide, and water in the hydrochloric acid-hydrogen peroxide aqueous solution is 1:1:4~6.

10. The wet cleaning process for the inner cavity pipeline of a sliding diaphragm solenoid valve according to claim 1, characterized in that: The nitric acid solution is nitric acid with a volume percentage concentration of 2-10%.

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