HIGH VISCOSITY RESIST PUMP

摘要

PURPOSE:To prevent the bellows from plastically deforming and breakdown- deterioration due to suction and discharge pressure of resist by a method wherein a means to pressurize the inside of bellows is provided to keep the balance with the resist pressure around the bellows. CONSTITUTION:When a cylinder 4 is lowered by reducing the feeding pressure from an air pump 20, the bellows 2 is contracted to suck resist into a space between outside of the bellows 2 and inside of a jacket 3 through an inlet 8. When the cylinder 4 is lifted by boosting the air pressure, the bellows 2 is extended to discharge the resist from an outlet 9. At this time, compressed air is fed to the jacket 3 through the intermediary of a tube 12 and a pressure regulator 5 to be led into the bellows 2 for keeping the balance with the peripheral resist pressure. Through these procedures, the bellows 2 can be prevented from plastically deforming and being damaged to assure the suction and discharge of resist in high reliability.