Patent ID: 6012607
Filing Date: 2000-01-11
Classification: B05C,H01L

Abstract:
A chemical solution dispensing system used to dispense a chemical solution onto a wafer, the system comprising:a switch valve, used to control whether the chemical solution is transported to the wafer or not, wherein the switch valve comprises a first input/output (I/O) end and a second I/O end, which are used to control the switch valve;a sucking-back valve, used to receive the chemical solution from the switch valve and transport the chemical solution to the substrate, wherein the sucking-back valve comprises a third I/O end to trigger a sufficient sucking force to just hold the chemical solution;a solenoid valve, triggering all switching actions to control the sucking-back valve and the switch valve, wherein the solenoid valve comprises an air-in end and an air-out end;a first speed controller, coupled between the air-in end and the first I/O end, and used to control the switching speed of the switch valve;a second speed controller, coupled between the air-out end and the second I/O end, and used to control the switching speed of the switch valve, wherein the second speed controller is also used to delay the switching speed of the sucking-back valve for producing or releasing the sucking force; anda sucking-back speed controller, coupled between the third I/O end of the sucking-back valve and a place, which is between the second I/O end and the second speed controller, wherein sucking-back speed controller is used together with the second speed controller to delay switching speed of the sucking-back valve,wherein while the solenoid valve triggering the switching actions to control the sucking-back valve and the switch valve, the switch valve is switched on/off through the first and the second speed controllers, and the sucking-back valve is activated with a delay time resulting from the additional sucking-back speed controller.