What is the purpose of a vacuum pump?
Thread Content
I would like to ask everyone what purpose vacuum pumps serve in single-crystal silicon factories? Could you be more detailed? Thank you :)
Mainly replacing the furnace yields better results
Reply to 2# summerday: I’m sorry, could you explain it in more detail? I’m a beginner
Czochralski crystal growth furnaces use argon as a protective atmosphere. If argon is used to directly displace the air inside the furnace, it results in significant waste of argon and makes it difficult to achieve complete displacement. First, use a vacuum pump to evacuate the furnace to below 3 Pa, then fill it with Ar gas, and heating and drawing can be carried out directly!
The vacuum pumps in our factory are also used in refrigeration units to introduce CFCs, to evacuate the system, and to deliver the CFCs using pressure differences.
It is mainly used for vacuum creation; systems that require negative pressure rely on it. Before starting up with trichlorosilane, hydrogen is introduced under negative pressure to initiate ignition. Vacuum pumps are also needed for furnace purging or removing slag from the system, as well as for handling silica gel. There are also some simple applications, as mentioned above
The vacuum chamber, which is formed by the main vacuum pump, filtration tank, main vacuum pipes, main pipeline valves, as well as the lower furnace cylinder; the magnetohydraulic fluid in the crucible being connected to the furnace base through lower shaft bellows; and all these components being sealed together by rubber rings with the lower furnace cylinder, main furnace cylinder, furnace lid, valve chamber for flipping the crystal, auxiliary vacuum pipes, valves, auxiliary vacuum pump, secondary chambers, transition sub-chambers, small bellows, pulley box, as well as the magnetohydraulic fluids used for rotating and lifting the crystal, is referred to as the vacuum system of the single-crystal furnace. By switching the flap valve, the pressure and temperature in the main furnace chamber are maintained to meet the requirements of the single crystal growth process, thereby completing the growth of the single crystal.
An environment with a pressure lower than atmospheric pressure inside a sealed container is called a vacuum. A system that is used to meet certain process requirements, and is capable of achieving and measuring a specific vacuum level, is called a vacuum system. It is divided into five categories: coarse, low, high, ultra, and extremely high. The single crystal furnace is a low-vacuum system (with an operating pressure in the range of 1330–0.13 Pa, which falls within the low-vacuum category); it is a dynamic vacuum system. (Composed of multiple components, with numerous welds between them and several detachable sealing joints) The vacuum pump functions like an organ in the human body for polycrystalline and single-crystal furnaces ； The functions of the lungs.
Reply to 8# sunyu_98: Thank you very much; now I understand!
Reply to 6# kuristying-1: Thank you very much for your reply!
Reply to 4# oceans998: Thank you, thanks for your help!