High Vacuum Pumps
High Vacuum Pumps play an important role in the semiconductor fabrication process. A pump, with a piston and motor attached, is used to pressurize a flow of either a liquid or a gas through a small opening. The pump's operation basically consists of pumping a liquid through the pump by means of a temporary airtight seal. Pumps are also employed in the chemical reaction chamber as part of a larger system, to create an exothermic, or exfoliating, vapor. Vacuum pumps have developed vastly over the years as one of the most vital pieces of equipment used today in the fabrication process. While they had initially been developed for use in the aerospace industry (as might be expected), industrial applications have seen a great deal of progress in recent years.
High Vacuum Pumps: Vacuum Pumps (HVLP) operate under very high pressure conditions. They are sometimes used to transfer heat between two pieces of metal. Because of their high pressure, high vacuum pumps require a very large and very strong pump for efficient operation. As such, they cannot be used in many residential applications because of their size and strength requirements. Commercial applications have been seeing a lot of progress in recent years because of advances in pump technology, and because of the pressure they can handle.
High Vacuum Pumps: The principle of operation is usually a matter of injecting a gas (usually a refrigerant) into a closed chamber to produce a temporary vacuum. Once that is achieved, the injector is pushed further into the chamber to achieve higher pressures. This process continues until a breaking point is reached. The most common applications requiring vacuum pumping speeds over a hundred Kps are HVLP dry cell batteries and vacuum pumps used in combustion systems.
Molecular distillation: This process is also known as fractional distillation. The basic difference between this process and fractional distillation is that in molecular distillation, there is no need to remove solvent molecules. Solvent molecules can simply be vaporized and used again. This can reduce the cost and effort associated with distillation and make it an economically viable alternative for many applications requiring higher vapor pressure.
High Vacuum Pumps and Their Applications: These pumps are also used in applications requiring high vacuum strengths and temperatures. High vacuum strengths are attained by injecting higher concentrations of a gas into a smaller pump or by increasing the volume of a medium into a smaller pump. Many vacuum strengths can be achieved through the use of high-vacuum power supplies. These pumps can also be used in applications requiring momentum transfer pump action. Momentum transfer pumps are designed to push liquid or gas out of a sample at very high velocities.
Types of High Vacuum Pumps: There are three different types of vacuum pumps. High static pressure, high static electricity and high dynamic pressure. High static pressure pumps have a shaft seal and a piston. In high static electricity, there is only one electric motor and a diaphragm is used to lower the dynamic pressure. A third type of vacuum pump exists and is referred to as a dynamic vacuum pump which has no permanent fluids and it does not generate vibrations.
Benefits and Disadvantages: The key benefits of vacuum pumps are that they are efficient, durable and safe. They can be used in a wide range of industrial and commercial settings. They do not emit aerosols, create dust and produce very little noise. They are available in a number of different configurations and cost. They have variable speed controls and high efficiency performance.
There are three major disadvantages of high vacuum pumps. First, it is expensive and difficult to maintain and secondly, they have very little life span. Lastly, they do not generate enough thrust for consistent pumping action. A common solution to this problem is a high vacuum pump kinetic energy transfer device or AMED.
