What are the specific requirements for the performance of customized gas seals in the semiconductor and lithium battery industries?
Publish Time: 2024-08-22
The performance requirements for customized gas seals in the semiconductor and lithium battery industries are as follows:
1. Sealing
High airtightness:
During the manufacturing process of semiconductors and lithium batteries, it is necessary to strictly control the entry of impurities such as particles, moisture, and oxygen in the environment. The gas seal must have extremely high airtightness and can effectively prevent external air and impurities from penetrating into the internal clean environment or key components. For example, in the dust-free workshop of semiconductor wafer manufacturing, the gas seal must ensure that the size of dust particles in the air is controlled below the nanometer level to prevent it from contaminating the surface of the wafer and affecting the performance and yield of the chip.
For lithium batteries, the intrusion of moisture may cause electrolyte decomposition, battery performance degradation, and even safety accidents. The gas seal must be able to control the moisture content at an extremely low level, usually required to be less than one part per million.
Pressure stability:
Whether in different pressure environments in semiconductor processing equipment or changes in internal pressure of lithium batteries during charging and discharging, the gas seal should be able to maintain stable sealing performance. For example, in the semiconductor chemical vapor deposition (CVD) process, the inside of the equipment may experience a cycle change from normal pressure to high vacuum and then to a certain pressure. The gas seal needs to maintain a good seal under this dynamic pressure environment.
When the lithium battery is charged and discharged, a certain pressure change will occur inside. The gas seal must be able to adapt to this pressure fluctuation to prevent gas leakage or external air from entering.
2. Material compatibility
Corrosion resistance:
Various chemicals, such as strong acids, strong alkalis, and organic solvents, are used in the production process of semiconductors and lithium batteries. The gas seal material must have good corrosion resistance and be able to resist the erosion of these chemicals to ensure that the seal will not fail due to corrosion during long-term use. For example, in the semiconductor wet cleaning process, various corrosive chemical reagents are used, and the gas seal material must be able to remain stable under the action of these reagents.
The electrolyte in the lithium battery is also corrosive to a certain extent. The part of the gas seal that contacts the electrolyte needs to be made of materials that are resistant to electrolyte corrosion.
Low outgassing:
In the high vacuum environment of semiconductor manufacturing, the gas released by any material may contaminate the surface of the wafer and affect the performance of the chip. The gas sealing material should have an extremely low outgassing rate to ensure that no harmful gases or impurities are released during use. For example, some special fluororubber materials, after strict processing and screening, can meet the semiconductor industry's requirements for low outgassing.
For lithium batteries, the gas released by the gas sealing material may also react with the chemicals inside the battery, affecting the battery's performance and safety. Therefore, the gas sealing material must undergo rigorous testing to ensure that its outgassing meets the requirements for the use of lithium batteries.
Compatibility with specific media:
In the semiconductor industry, the gas seal may come into contact with various special gases (such as nitrogen, hydrogen, helium, etc.). The material needs to have good compatibility with these gases and will not undergo chemical reactions or physical changes that affect the sealing performance. For example, in some semiconductor processes, hydrogen is used as a reducing gas, and the gas sealing material must be able to remain stable in a hydrogen environment.
The electrolyte in a lithium battery is usually composed of an organic solvent and a lithium salt. The gas sealing material must have good compatibility with the electrolyte and will not be dissolved, swelled, or have other adverse reactions.
3. Temperature adaptability
Wide temperature range:
During semiconductor processing, the equipment may experience temperature changes from extremely low temperatures (such as liquid nitrogen cooling environment) to high temperatures (such as hundreds of degrees Celsius in wafer annealing process). The gas seal needs to maintain good sealing performance and mechanical strength in such a wide temperature range. For example, in some semiconductor processes, quantum computing-related operations need to be performed at extremely low temperatures, and the gas seal must be able to maintain sealing in such an extreme low temperature environment.
Lithium batteries also generate a certain amount of heat during the charging and discharging process, especially during fast charging or high-power discharge, the temperature may rise. The gas seal must be able to work normally within the operating temperature range of the lithium battery and will not cause sealing failure due to temperature changes.
Temperature stability:
At different temperatures, the dimensional stability and mechanical properties of the gas seal material cannot change significantly. For example, it cannot become soft or deformed due to temperature increase, resulting in poor sealing; it cannot become brittle or cracked due to temperature decrease, affecting the sealing effect. For the semiconductor and lithium battery industries, temperature stability is one of the key factors to ensure long-term stable operation of equipment.
4. Mechanical properties
Strength and wear resistance:
The gas seal may be subjected to certain mechanical pressure and friction during installation and use. The material needs to have sufficient strength and wear resistance to withstand the extrusion during installation and the friction during use, to ensure that there will be no damage, wear and other problems during long-term use, which will affect the sealing performance. For example, in the moving parts of some semiconductor equipment, the gas seal needs to withstand frequent friction and extrusion and must have good wear resistance.
For lithium batteries, during assembly and use, the gas seal may also be subjected to certain external forces, such as battery expansion and contraction, vibration during transportation, etc. The gas seal material must have sufficient strength to resist these external forces and maintain sealing.
Elasticity and resilience:
The gas seal needs to have good elasticity and resilience to maintain a tight seal under different pressure and temperature conditions. When the pressure changes or the external force is eliminated, the gas seal can quickly return to its original shape and size to ensure that the sealing performance is not affected. For example, at the sealing interface of semiconductor equipment, the gas seal must be able to adapt to different pressure changes and always maintain a seal.
During the charging and discharging process of lithium batteries, the internal volume will change to a certain extent. The gas seal should be able to deform elastically with the expansion and contraction of the battery to maintain the seal.
5. Cleanliness
Low particle generation:
In the semiconductor manufacturing process, the control requirements for particles are very strict. The gas seal material should not produce too many particles during use to avoid contaminating the wafer surface or affecting the performance of the equipment. For example, the surface of the gas seal material should be smooth and not easy to produce wear particles; during the production and installation process, it must undergo strict cleaning treatment to ensure that no particles remain.
For lithium batteries, although the requirements for particles are relatively low, if the gas seal produces too many particles, it may also affect the performance and safety of the battery.
Easy to clean:
The gas seal should be easy to clean and can be effectively cleaned when necessary to remove surface contaminants and impurities. For example, the gas seal can be cleaned using a specific detergent or cleaning method without damaging the gas seal material or affecting its sealing performance. For the semiconductor industry, cleanliness is critical, and the easy cleanability of the gas seal can ensure that the equipment can be quickly switched and maintained between different processes.
