Patent ID: 7635410

Claim:
A photo-resist dispensing apparatus comprising: a tank adapted to hold a photo-resist solution; a pump unit adapted to pump the photo-resist solution from the tank; a filter unit adapted to receive the photo-resist solution from the pump unit; and a first gas discharge unit connected to the tank and adapted to remove gas bubbles from the photo-resist solution held in the tank, wherein the first gas discharge unit comprises; a first vacuum line coupled to an upper portion of the tank and adapted to discharge gas from the photo-resist solution in the tank, a first vacuum trap providing an airtight space adapted to regulate pumping pressure in the first vacuum line and collect the gas discharged from the first vacuum line, a second vacuum line connected between the first vacuum trap and a first vacuum pump, wherein the first vacuum pump is adapted to pump gas from the first vacuum trap, and a control valve associated with the first vacuum line and adapted to prevent external gas from back flowing into the tank through the first vacuum pump; and a second gas discharge unit connected to the filter unit and adapted to remove gas bubbles from the photo-resist solution in the filter unit, wherein the second gas discharge unit comprises; a third vacuum line coupled to an upper portion of the filter unit and adapted to discharge gas from the photo-resist solution in the filter unit, a second vacuum trap providing an airtight space adapted to regulate pumping pressure in the third vacuum line and collect the gas discharged from the filter unit, a fourth vacuum line connected between the second vacuum trap and a second vacuum pump, wherein the second vacuum pump is adapted to pump gas from the second vacuum trap, and a control valve associated with the third vacuum line and adapted to prevent external gas from back flowing into the filter unit through the second vacuum pump.