Understand the typical applications of ultra-high vacuum and high vacuum technologies(3)

Ultra-high vacuum and high vacuum valves are classified based on the range of vacuum degree. For different application scenarios, it is necessary to describe and define the characteristic attributes of valves from various dimensions. Additional conditions such as high gas pressure, strong magnetic field, low leakage, particle-free state (the state with the minimum number of particles achieved), valve plate cooling, valve body heating, valve body conductivity, corrosion resistance, metal dust, and high-temperature radiation impose higher requirements on valve performance.

Vacuum valves in the field of advanced integrated circuit manufacturing processes are advanced and representative. Valve products from companies like VAT, MKS, and VTES can meet the operational requirements of vacuum application equipment for deposition and etching: "no particle" generation (an extremely small amount of rubber and metal particles), no vibration induction (high-precision transmission), and precise control (no leakage, conductance adjustment). Particle-free valves are the foundation of high-end vacuum application equipment, distinguishing them from conventional vacuum valves: the metal valve body adopts high-vacuum brazing and dehydrogenation processes; the transmission seal uses metal bellows; rubber is firmly bonded to the valve plate and then undergoes vulcanization treatment; the rubber bears one-way sealing pressure without frictional movement.

In ultra-high vacuum systems, some components may generate particles during operation. Gases, liquid media (such as water, alcohol, or acid), or membrane filters are used for fine filtration to separate particles. Typically, particles with a size larger than 0.3μm are filtered out. Even in a vacuum environment without turbulence, it takes a relatively long time for particles to settle on the surface. For vacuum devices exposed to ambient air (without a filter), after being evacuated for several hours, the floating particles (larger than 0.2μm) in a non-turbulent flow state take approximately 80 hours to adhere to the surface and no longer be transported. When a vacuum valve is opened at 10mbar, particles detach from the adsorption surface due to vibration and turbulence and are transported along with the gas in the system. To obtain a particle-free vacuum system, measures should be taken to avoid significant vibration when the pressure is 1mbar.

Cleanliness levels are classified according to the size and quantity of particles in the air, with reference to the international standard ISO14644-1, as shown in Table 1. Accelerator components usually adopt environmental conditions of ISO Class 4 and ISO Class 5. During the assembly process, clean rooms use Filter Fan Units (FFUs) to filter the air; in mobile clean room tents, a local ISO Class 5 environment can be established

Ultra-high vacuum and high vacuum valves are classified according to the range of vacuum degree. For different application scenarios, it is also necessary to describe and define the characteristic attributes of valves from different dimensions. Additional conditions such as high gas pressure, strong magnetic field, low leakage, particle-free state (the state with the minimum number of particles achieved), valve plate cooling, valve body heating, valve body conductivity, corrosion resistance, metal dust, and high-temperature radiation put forward higher requirements for valve performance.

Vacuum valves in the field of advanced integrated circuit manufacturing processes are advanced and representative. Valve products from companies such as VAT, MKS, and VTES can meet the operational requirements of vacuum application equipment for deposition and etching: "no particle" generation (an extremely small amount of rubber and metal particles), no induction of vibration (high-precision transmission), and precise control (no leakage, conductance adjustment). Particle-free valves are the foundation of high-end vacuum application equipment, distinguishing them from conventional vacuum valves: the metal valve body adopts high-vacuum brazing and dehydrogenation processes; the transmission seal uses metal bellows; rubber is firmly bonded to the valve plate and then undergoes vulcanization treatment; the rubber bears one-way sealing pressure without frictional movement.

In ultra-high vacuum systems, some components may generate particles during operation. Gases, liquid media (such as water, alcohol, or acid) or membrane filters are used for fine filtration to separate particles. Typically, particles with a particle size larger than 0.3μm are filtered out. Even in a vacuum environment without turbulence, it takes a relatively long time for particles to settle on the surface. For vacuum devices exposed to ambient air (without a filter), after being evacuated for several hours, the floating particles (larger than 0.2μm) in a non-turbulent flow state take about 80 hours to adhere to the surface and no longer be transported. When a vacuum valve is opened at 10mbar, particles detach from the adsorption surface due to vibration and turbulence and are transported along with the gas in the system. To obtain a particle-free vacuum system, measures should be taken to avoid obvious vibration when the pressure is 1mbar.

Cleanliness levels are classified according to the size and quantity of particles in the air, with reference to the international standard ISO14644-1, as shown in Table 1. Accelerator components usually adopt environmental conditions of ISO Class 4 and ISO Class 5. During the assembly process, clean rooms use Filter Fan Units (FFUs) to filter the air; in mobile clean room tents, a local ISO Class 5 environment can be established.