Vacuum pump and sensor target

Abstract

To provide a vacuum pump and a sensor target which widen the range of linearity of sensor sensitivity at a lower price than when a ferromagnetic material is used in a sensor target of a displacement sensor and make touchdown difficult when a disturbance is generated. An axial displacement sensor 109 is configured by winding a coil 7 on a bobbin 109B attached to an upper end of an axial part 109A which passes through and is fixed to the center of a holding member 5 that holds an axial electromagnet 106. An axial end 113B of a small diameter column shape is projected at a lower end of a rotor shaft 113 with a gap 2 between the axial end 113B and the coil 7. A male screw is engraved on the outer periphery of the axial end 113B, and a nut 19 having an engraved female screw therein is screwed into the axial end 113B. However, the range in which the female screw is engraved is stopped at an intermediate portion of the nut 19 without passing through the nut 19. That is, the nut 19 has a screwhole 19A which is opened only at an upper portion thereof. The nut 19 is formed of one among low carbon steel materials.

Description

technical field [0001] The present invention relates to a vacuum pump and a sensor target, and in particular to a vacuum pump and a sensor target that can expand the range of linearity of sensor sensitivity more cheaply when a ferromagnetic material is used for the sensor target of a displacement sensor, and is less prone to bottoming out when a disturbance occurs. Dawn). Background technique [0002] With the development of electronic engineering in recent years, the demand for semiconductors such as memories and integrated circuits has increased rapidly. [0003] These semiconductors are produced by doping an extremely pure semiconductor substrate with impurities to impart electrical properties, and forming fine circuits on the semiconductor substrate by etching. [0004] In addition, these operations need to be performed in a chamber in a high vacuum state in order to avoid the influence of dust in the air and the like. Generally, a vacuum pump is used to exhaust the ch...

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Problems solved by technology

[0013] In particular, it is difficult to obtain linearity in sensor sensitivity where the gap 2 is large, and as a result, the gap 2 between the lower end of the rotor shaft 113 and the axial displacement sensor 1 cannot be ensured to be sufficiently large.

In this case, when the vibration from the outside such as an earthquake or the turbomolecular pump discharges the gas in the chamber, the gas (atmosphere) is suddenly introduced for some reason, and the vacuum state is opened to the atmosphere. When the rotor swings, the The gap 2 is small, and it may also cause bottoming

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