Passivating treatment method for steel cylinder for storing high-purity electronic mixed gas

Abstract

The invention provides a passivating treatment method for a steel cylinder for storing high-purity electronic mixed gas. The passivating treatment method comprises the following specific steps: S1, vacuumizing the steel cylinder to be treated; s2, in a high-temperature environment, carrying out balance gas replacement treatment on the steel cylinder; s3, after the replacement gas in the steel cylinder is vacuumized, the steel cylinder is placed in a high-temperature environment after being filled with passivation gas; s4, after the passivation gas in the steel cylinder is vacuumized, balance gas is introduced for replacement treatment; and S5, the steel cylinder is vacuumized, and the steel cylinder is filled with high-purity electronic mixed gas. The high-purity electronic mixed gas stored in the treated steel cylinder is stable in index within 2 years, and good product quality stability is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of chemical engineering, and in particular to a passivation treatment method for a steel cylinder storing high-purity electronic mixed gas. Background Art

[0002] High-purity electronic mixed gas is an essential supporting material for industries such as integrated circuits and display panels. The quality of high-purity electronic mixed gas has a significant impact on the performance and yield of semiconductors and display devices. Therefore, there are high requirements for the purity and relative deviation of the components of high-purity electronic mixed gas.

[0003] The cleanliness of the packaging container greatly affects the quality stability of the gas stored inside it. Generally speaking, there will be residual moisture inside the newly purchased cylinder that is difficult to remove. Under certain conditions, high-purity electronic mixed gases (such as hydrogen, oxygen, and fluorine) will react with the inner wall of the container to produce other impurities and water, resulting in unstable impurity content in the gas, affecting the quality of the product. Summary of the invention

[0004] The purpose of the present invention is to provide a passivation treatment method for a steel cylinder storing high-purity electronic mixed gas. The high-purity electronic mixed gas stored in the steel cylinder treated by the method has stable indicators within two years.

[0005] The technical solution adopted by the present invention is:

[0006] A passivation treatment method for a steel cylinder storing high-purity electronic mixed gas comprises the following steps:

[0007] S1: Vacuum the cylinder to be treated;

[0008] S2: In a high temperature environment, the cylinder is subjected to balanced gas replacement treatment;

[0009] S3: After the replacement gas inside the cylinder is evacuated, it is filled with passivation gas and placed in a high temperature environment;

[0010] S4: After the passivation gas in the cylinder is evacuated, the balance gas is introduced for replacement;

[0011] S5: Evacuate the steel cylinder and fill it with high-purity electronic mixed gas.

[0012] Preferably, after the passivation treatment is completed, the steel cylinder is evacuated to a pressure of ≤-0.10 MPa in S5, and a high-purity electronic mixed gas with a purity of ≥99.999% is filled into the steel cylinder, and the gas is stored for 2 years with stable indicators.

[0013] Preferably, the high-purity electronic mixed gas in S5 is a mixture of two or more of helium, nitrogen, argon, neon, krypton, xenon, hydrogen, ammonia, oxygen, nitrogen trifluoride, hydrogen chloride, nitric oxide, sulfur dioxide, diborane, phosphine and fluorine.

[0014] Preferably, the material of the steel cylinders in S1-S5 includes carbon steel and stainless steel.

[0015] Preferably, in S1, the steel cylinder to be treated is evacuated to a pressure of ≤-0.10 MPa.

[0016] Preferably, the purity of the balance gas used in the replacement treatment in S2 is ≥99.9999%, the number of replacement treatments in S2 is not less than 3 times, and the ambient temperature is 50-60°C, which is conducive to removing water from the inner wall of the cylinder. The balance gas is helium, argon, nitrogen or neon.

[0017] Preferably, S3 is evacuated to a pressure ≤-0.10MPa, the passivation gas is charged at a pressure of 0.5-1MPa, the temperature of the high-temperature environment is 50-60°C, and the cylinder is left to stand for no less than 7 days after the passivation gas is charged in S3, which is conducive to the formation of a passivation film on the inner wall of the cylinder.

[0018] Preferably, the types of passivation gases filled into different high-purity electronic mixed gas cylinders in S3 are as follows:

[0019] (1) When the high-purity electronic mixed gas is a hydrogen-containing mixed gas, the passivation gas type is high-purity hydrogen or high-purity hydrogen-containing mixed gas;

[0020] (2) When the high-purity electronic mixed gas is a mixed gas containing ammonia, the passivation gas type is high-purity ammonia or a high-purity mixed gas containing ammonia; (3) When the high-purity electronic mixed gas is a mixed gas containing oxygen, the passivation gas type is high-purity oxygen or a high-purity mixed gas containing oxygen; (4) When the high-purity electronic mixed gas is a mixed gas containing nitrogen trifluoride, the passivation gas type is high-purity nitrogen trifluoride or a high-purity mixed gas containing nitrogen trifluoride;

[0021] (5) When the high-purity electronic mixed gas is a mixed gas containing hydrogen chloride, the passivation gas type is high-purity hydrogen chloride or a high-purity mixed gas containing hydrogen chloride;

[0022] (6) When the high-purity electronic mixed gas is a mixed gas containing nitric oxide, the passivation gas type is high-purity carbon monoxide or a high-purity mixed gas containing carbon monoxide;

[0023] (7) When the high-purity electronic mixed gas is a mixed gas containing sulfur dioxide, the passivation gas type is high-purity sulfur dioxide or a high-purity mixed gas containing sulfur dioxide;

[0024] (8) When the high-purity electronic mixed gas is a mixed gas containing diborane, the passivation gas type is high-purity diborane or a high-purity mixed gas containing diborane;

[0025] (9) When the high-purity electronic mixed gas is a phosphine-containing mixed gas, the passivation gas type is high-purity phosphine or a high-purity phosphine-containing mixed gas;

[0026] (10) When the high-purity electronic mixed gas is a fluorine-containing mixed gas, the passivation gas type is high-purity fluorine gas or high-purity fluorine-containing mixed gas.

[0027] Preferably, in S4, the passivation gas in the cylinder is evacuated to a pressure of ≤-0.10 MPa, the purity of the balance gas is ≥99.9999%, and the balance gas is helium, argon, nitrogen or neon.

[0028] Preferably, the charged high-purity electronic mixed gas is tested every six months, and the tests are performed three times in parallel.

[0029] Note: High-purity gas refers to gas with a purity of ≥99.999%.

[0030] Beneficial effects of the present invention:

[0031] In order to ensure the stability of the quality of high-purity electronic mixed gas, the present invention proposes a steel cylinder passivation treatment method, which performs replacement pretreatment on the steel cylinder by balancing gas in a high-temperature environment to remove impurities and moisture in the steel cylinder. Subsequently, the steel cylinder is filled with passivation gas to form a uniform passivation film on the inner wall. The steel cylinder treated by the present invention stores high-purity electronic mixed gas, and the gas purity can be maintained for two years, thereby improving the stability of product quality.

[0032] Compared with the prior art, the present invention firstly adopts balanced gas replacement treatment in a high temperature environment to remove the impurities and moisture remaining in the cylinder, and then fills in the passivation gas and places it in a high temperature environment to further remove the impurities and moisture attached to the inner wall of the cylinder, thereby forming a passivation film on the inner wall. The stored gas has stable indicators within 2 years, which greatly improves the stability of product quality. DETAILED DESCRIPTION

[0033] The specific implementation modes of the present invention are described in detail below, but are not intended to limit the protection scope of the present invention.

[0034] Example 1

[0035] The present invention provides a passivation treatment method for a steel cylinder storing high-purity electronic mixed gas, and the specific steps are as follows:

[0036] S1: Vacuum the carbon steel cylinder to be treated until the pressure is ≤-0.10MPa;

[0037] S2: The ambient temperature is set to 55°C, and the cylinder is subjected to balance gas replacement treatment 3 times, using ultra-pure helium (balance gas) with a purity of ≥99.9999%;

[0038] S3: After the replacement gas inside the cylinder is evacuated to a pressure of ≤-0.10MPa, 0.5-1MPa high-purity oxygen with a purity of ≥99.999% is filled into the cylinder for passivation treatment;

[0039] S4: The ambient temperature is set to 55°C and left for 7 days;

[0040] S5: After the passivation gas in the cylinder is evacuated to a pressure of ≤-0.10MPa, ultrapure helium is introduced for replacement. The purity of the ultrapure helium used is ≥99.9999%;

[0041] S6: After the steel cylinder is evacuated to a pressure of ≤-0.10MPa, a 30% O2 / He mixed gas with a purity of ≥99.9999% is filled into the steel cylinder.

[0042] The changes in gas indicators in cylinders within 2 years of storage are shown in Table 1.

[0043] Table 1 Changes in indicators of 30% O2 / He gas

[0044]

[0045]

[0046] The test results show that within 2 years of storage, the impurity contents are within the product specification line and the product quality is stable.

[0047] Example 2

[0048] The present invention provides a passivation treatment method for a steel cylinder storing high-purity electronic mixed gas, and the specific steps are as follows:

[0049] S1: Vacuum the carbon steel cylinder to be treated until the pressure is ≤-0.10MPa;

[0050] S2: The ambient temperature is set to 50°C, and the cylinder is replaced with balance gas. The purity of the ultra-pure nitrogen (balance gas) used is ≥99.9999%;

[0051] S3: After the replacement gas inside the cylinder is evacuated to a pressure of ≤-0.10MPa, 0.5-1MPa ultrapure hydrogen with a purity of ≥99.9999% is filled into the cylinder for passivation treatment;

[0052] S4: The ambient temperature is set to 50°C and left for 7 days;

[0053] S5: After the passivation gas in the cylinder is evacuated to a pressure of ≤-0.10MPa, ultrapure nitrogen is introduced for replacement. The purity of the ultrapure nitrogen used is ≥99.9999%;

[0054] S6: After the steel cylinder is evacuated to a pressure of ≤-0.10MPa, a 4% H2 / N2 mixed gas with a purity of ≥99.9999% is filled into the steel cylinder.

[0055] The changes in gas indicators in cylinders within 2 years of storage are shown in Table 2.

[0056] Table 2 Changes in indicators of 4% H2 / N2 gas

[0057]

[0058]

[0059] The test results show that within 2 years of storage, the impurity contents are within the product specification line and the product quality is stable.

[0060] Example 3

[0061] The present invention provides a passivation treatment method for a steel cylinder storing high-purity electronic mixed gas, and the specific steps are as follows:

[0062] S1: Vacuum the carbon steel cylinder to be treated until the pressure is ≤-0.10MPa;

[0063] S2: The ambient temperature is set to 50°C, and the cylinder is replaced with balance gas. The purity of the ultra-pure nitrogen (balance gas) used is ≥99.9999%;

[0064] S3: After the replacement gas inside the cylinder is evacuated to a pressure of ≤-0.10MPa, a 4% H2 / N2 mixed gas with a purity of ≥99.9999% of 0.5-1MPa is filled into the cylinder for passivation treatment;

[0065] S4: The ambient temperature is set to 50°C and left for 7 days;

[0066] S5: After the passivation gas in the cylinder is evacuated to a pressure of ≤-0.10MPa, ultrapure nitrogen is introduced for replacement. The purity of the ultrapure nitrogen used is ≥99.9999%;

[0067] S6: After the steel cylinder is evacuated to a pressure of ≤-0.10MPa, a 4% H2 / N2 mixed gas with a purity of ≥99.9999% is filled into the steel cylinder.

[0068] The changes in gas indicators in the cylinders within 2 years are shown in Table 3.

[0069] Table 3 Index changes of 4% H2 / N2 gas

[0070]

[0071]

[0072] The test results show that within 2 years of storage, the hydrogen content and moisture content showed obvious changes, and the moisture content index was unqualified after one year.

[0073] Comparison between Example 2 and Example 3 shows that when ultrapure hydrogen and 4% H2 / N2 mixed gas are used to passivate 4% H2 / N2 product cylinders, although the passivation using 4% H2 / N2 mixed gas can save costs to a certain extent, the passivation effect is poor and the moisture index is unqualified, indicating that it is more appropriate to use ultrapure hydrogen as the passivation gas when passivating hydrogen-containing mixed gas.

[0074] Example 4

[0075] The present invention provides a passivation treatment method for a steel cylinder storing high-purity electronic mixed gas, and the specific steps are as follows:

[0076] S1: Vacuum the carbon steel cylinder to be treated until the pressure is ≤-0.10MPa;

[0077] S2: Replace the steel cylinder with balance gas, and use ultra-pure neon gas (balance gas) with a purity of ≥99.9999%;

[0078] S3: After the replacement gas inside the cylinder is evacuated to a pressure of ≤-0.10MPa, 0.5-1MPa ultrapure hydrogen with a purity of ≥99.9999% is filled into the cylinder for passivation treatment;

[0079] S4: The ambient temperature is set to 50°C and left for 7 days;

[0080] S5: After the passivation gas in the cylinder is evacuated to a pressure of ≤-0.10MPa, ultrapure neon gas is introduced for replacement treatment. The purity of the ultrapure neon gas used is ≥99.9999%;

[0081] S6: After evacuating the steel cylinder to a pressure of ≤-0.10MPa, fill the steel cylinder with 100ppmH2 / Ne mixed gas with a purity of ≥99.9999%.

[0082] The changes in gas indicators in the cylinders within 2 years are shown in Table 4.

[0083] Table 4 Index changes of 100ppmH2 / Ne gas

[0084]

[0085]

[0086] The test results show that within 2 years of storage, the hydrogen component content gradually increased, and the component was unqualified after one year. Other indicators were relatively stable, the impurity content was within the product specification line, and the product quality was stable.

[0087] Example 5

[0088] The present invention provides a passivation treatment method for a steel cylinder storing high-purity electronic mixed gas, and the specific steps are as follows:

[0089] S1: Vacuum the carbon steel cylinder to be treated until the pressure is ≤-0.10MPa;

[0090] S2: Replace the steel cylinder with balance gas, and use ultra-pure neon gas (balance gas) with a purity of ≥99.9999%;

[0091] S3: After the replacement gas inside the cylinder is evacuated to a pressure of ≤-0.10MPa, 0.5-1MPa 100ppm H2 / Ne mixed gas with a purity of ≥99.9999% is filled into the cylinder for passivation treatment;

[0092] S4: The ambient temperature is set to 50°C and left for 7 days;

[0093] S5: After the passivation gas in the cylinder is evacuated to a pressure of ≤-0.10MPa, ultrapure neon gas is introduced for replacement treatment. The purity of the ultrapure neon gas used is ≥99.9999%;

[0094] S6: After evacuating the steel cylinder to a pressure of ≤-0.10MPa, fill the steel cylinder with 100ppmH2 / Ne mixed gas with a purity of ≥99.9999%.

[0095] The changes in gas indicators in cylinders within 2 years of storage are shown in Table 5.

[0096] Table 5 Index changes of 100ppmH2 / Ne gas

[0097]

[0098]

[0099] The test results show that within 2 years of storage, the impurity contents are within the product specification line and the product quality is stable.

[0100] Comparison between Example 4 and Example 5 shows that when ultrapure hydrogen and 100ppmH2 / Ne mixed gas are used to passivate 100ppmH2 / Ne finished cylinders respectively, ultrapure hydrogen as a passivation gas has a greater impact on the components of the finished product, indicating that when passivating a low concentration (ppm level) mixed gas, it is more appropriate to use the corresponding mixed gas as the passivation gas considering the impact on the finished product components.

[0101] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent change made to the above embodiment according to the technical essence of the invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A passivation treatment method for a steel cylinder storing high-purity electronic mixed gas, characterized in that: The steps include: S1: Vacuum the cylinder to be treated; S2: In a high temperature environment, the cylinder is subjected to balanced gas replacement treatment; S3: After the replacement gas inside the cylinder is evacuated, it is filled with passivation gas and placed in a high temperature environment; S4: After the passivation gas in the cylinder is evacuated, the balance gas is introduced for replacement; S5: Evacuate the steel cylinder and fill it with high-purity electronic mixed gas.

2. A passivation treatment method for storing high-purity electronic mixed gas cylinders according to claim 1, characterized in that: After the passivation treatment is completed, the steel cylinder is evacuated in S5 to a pressure of ≤-0.10MPa, and a high-purity electronic mixed gas with a purity of ≥99.999% is filled into the steel cylinder. The gas is stored for 2 years and its indicators are stable.

3. A passivation treatment method for storing high-purity electronic mixed gas cylinders according to claim 1, characterized in that: The high-purity electronic mixed gas in S5 is a mixture of two or more of helium, nitrogen, argon, neon, krypton, xenon, hydrogen, ammonia, oxygen, nitrogen trifluoride, hydrogen chloride, nitric oxide, sulfur dioxide, diborane, phosphine and fluorine.

4. A passivation treatment method for storing high-purity electronic mixed gas cylinders according to claim 1, characterized in that: The materials of the cylinders in S1-S5 include carbon steel and stainless steel.

5. A passivation treatment method for storing high-purity electronic mixed gas cylinders according to claim 1, characterized in that: In S1, the steel cylinder to be processed is evacuated to a pressure of ≤-0.10MPa.

6. A passivation treatment method for storing high-purity electronic mixed gas cylinders according to claim 1, characterized in that: The purity of the balance gas used in the replacement process in S2 is ≥99.9999%, the number of replacement processes in S2 is not less than 3 times, the ambient temperature is 50-60°C, and the balance gas is helium, argon, nitrogen or neon.

7. A passivation treatment method for storing high-purity electronic mixed gas cylinders according to claim 1, characterized in that: S3 is evacuated to a pressure of ≤-0.10MPa, and the passivation gas is filled with a pressure of 0.5-1MPa. The temperature of the high-temperature environment is 50-60℃. After S3 is filled with the passivation gas, the cylinder is left to stand for no less than 7 days.

8. A passivation treatment method for a steel cylinder storing high-purity electronic mixed gas according to claim 1, characterized in that: The types of passivation gases filled into different high-purity electronic mixed gas cylinders in S3 are as follows: (1) When the high-purity electronic mixed gas is a hydrogen-containing mixed gas, the passivation gas type is high-purity hydrogen or high-purity hydrogen-containing mixed gas; (2) When the high-purity electronic mixed gas is a mixed gas containing ammonia, the passivation gas type is high-purity ammonia or a high-purity mixed gas containing ammonia; (3) When the high-purity electronic mixed gas is an oxygen-containing mixed gas, the passivation gas type is high-purity oxygen or high-purity oxygen-containing mixed gas; (4) When the high-purity electronic mixed gas is a mixed gas containing nitrogen trifluoride, the passivation gas type is high-purity nitrogen trifluoride or a high-purity mixed gas containing nitrogen trifluoride; (5) When the high-purity electronic mixed gas is a mixed gas containing hydrogen chloride, the passivation gas type is high-purity hydrogen chloride or a high-purity mixed gas containing hydrogen chloride; (6) When the high-purity electronic mixed gas is a mixed gas containing nitric oxide, the passivation gas type is high-purity carbon monoxide or a high-purity mixed gas containing carbon monoxide; (7) When the high-purity electronic mixed gas is a mixed gas containing sulfur dioxide, the passivation gas type is high-purity sulfur dioxide or a high-purity mixed gas containing sulfur dioxide; (8) When the high-purity electronic mixed gas is a mixed gas containing diborane, the passivation gas type is high-purity diborane or a high-purity mixed gas containing diborane; (9) When the high-purity electronic mixed gas is a phosphine-containing mixed gas, the passivation gas type is high-purity phosphine or a high-purity phosphine-containing mixed gas; (10) When the high-purity electronic mixed gas is a fluorine-containing mixed gas, the passivation gas type is high-purity fluorine gas or high-purity fluorine-containing mixed gas.

9. A passivation treatment method for a steel cylinder storing high-purity electronic mixed gas according to claim 1, characterized in that: In S4, the passivation gas in the cylinder is evacuated to a pressure of ≤-0.10MPa, and the purity of the balance gas is ≥99.9999%, and the balance gas is helium, argon, nitrogen or neon.

10. A passivation treatment method for a steel cylinder storing high-purity electronic mixed gas according to claim 2, characterized in that: The high-purity electronic mixed gas filled in is tested every six months, and the tests are carried out three times in parallel.

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