GB/T 34085-2017 in English

Interpretation of the National Standard of the People's Republic of China GB/T 34085-2017

Standard Name: Gas for electronic industry—Trifluoromethane

Release Date:This standard was drafted in accordance with the rules given in GB/T1.1-2009.

1. Background and formulation of the standard

Trifluoromethane (CHF₃), as an important electronic industrial gas, is widely used in plasma etching processes in semiconductor manufacturing. With the rapid development of the electronics industry, the demand for high-purity gases is increasing.

This standard was proposed and coordinated by the National Technical Committee for Standardization of Semiconductor Equipment and Materials (SAC/TC203), and the main drafting units include the National Chemical Industry Gas Product Quality Supervision and Inspection Center (Fujian), Guangdong Huate Gas Co., Ltd., etc.

2. Scope and applicability of the standard

3. Comparison of technical requirements and indicators

The quality of trifluoromethane should meet the requirements of Table 1. The following is a comparison of key indicators:

4. Test methods and technical details

The detection of trifluoromethane includes indicators such as purity, impurity content and acidity. The following are key test methods:

• Purity calculation:The formula is Φ=100−Φ₇×10⁻⁴, where Φ₇ is the total impurity content.
• Acidity determination:The titration reaction is carried out using a sodium hydroxide standard solution and a sulfuric acid standard titration solution, and the end point is determined using a mixed indicator (methyl red-bromocresol green).

5. Packaging, marking and storage and transportation safety

The filling and transportation of trifluoromethane must comply with relevant regulations, including:

• Gas cylinder requirements:Comply with GB/T5099 regulations, and CGA320 connection method is recommended.
• Packaging mark:It should indicate the words "electronic grade trifluoromethane" and attach a quality certificate.
• Storage requirements:Store in a cool, dry, ventilated warehouse, away from heat sources.

6. Safety warning

Trifluoromethane is asphyxiating and colorless and odorless. The following safety precautions should be noted:

• Avoid contact with high temperature and flame to prevent decomposition and production of hydrogen fluoride smoke.
• Use professional protective equipment to prevent gas leakage from causing harm to the human body.

7. Implementation Suggestions

To ensure the effective implementation of the standard:

• Purchasing stage:Choose gas cylinders that meet the requirements of GB/T 14193 and verify the product quality certificate.
• Testing stage:It is recommended to use high-precision instruments such as cavity ring-down spectrometer and gas chromatograph for impurity analysis.
• Operation training:Provide safety operation training to relevant personnel to ensure that they are familiar with key test methods such as acidity determination.