Patent ID: 8087429

Claim:
A multi-stage pump configured to dispense photoresist chemicals comprising: a pump inlet flow path; a pump outlet flow path; a feed pump in fluid communication with the pump inlet flow path comprising: a feed stage diaphragm movable in a feed chamber, wherein the feed stage diaphragm is a rolling diaphragm; a feed piston contacting the feed stage diaphragm throughout a full range of motion wherein movement of the feed piston causes the feed stage diaphragm to roll and unroll in a gap between the feed piston and a wall of the feed chamber; a feed motor coupled to the feed piston to reciprocate the feed piston; and a feed stage outlet flow path in fluid communication with the feed chamber; a dispense stage inlet flow path in fluid communication with a dispense chamber; a filter in fluid communication with the feed stage outlet flow path and the dispense stage inlet flow path such that fluid flowing from the feed pump to a dispense pump passes through the filter; the dispense pump in fluid communication with the feed pump and the pump outlet flow path, the dispense pump comprising: a dispense diaphragm movable in the dispense chamber, wherein the dispense diaphragm comprises a dispense rolling diaphragm; a dispense piston contacting the dispense diaphragm throughout a full range of motion, wherein movement of the dispense piston causes the dispense diaphragm to roll and unroll in a gap between the dispense piston and wall of the dispense chamber; and a dispense motor coupled to the dispense piston to reciprocate the dispense piston; a dispense block formed of a single piece of material defining at least a portion of the feed chamber and at least a portion of the dispense chamber; and a set of valves to selectively allow fluid flow through the multi-stage pump.