Patent ID: 6062442
Filing Date: 2000-05-16
Classification: H01L

Abstract:
A chemical solution dispensing system used to dispense a chemical solution onto a substrate, the system comprising:a pump, used to transport the chemical solution, wherein the pump comprises a first input/output (I/O) end and a second I/O end;a sucking-back valve, receiving the chemical solution from the pump and allowing the chemical solution to be dispensed onto the substrate, wherein the sucking-back valve comprises a third I/O end used to be triggered to produce or release a sucking force on the chemical solution;a solenoid valve, performing a switch function to control the pump and the sucking-back valve, wherein the solenoid comprises an input end and an output end;a first pump speed controller, coupled between the first I/O end of the pump and the input end, used to control the switching speed of the pump;a second pump speed controller, coupled between the second I/O end of the pump and the output end, used to control the switching speed of the pump; anda sucking-back speed controller, coupled between the third I/O end of the sucking-back valve and a route between the second I/O end of the pump and the second pump speed controller, used to control the switching speed of the sucking-back valve;wherein, during the solenoid valve switching on/off the pump for dispensing status of the chemical solution to the substrate, the sucking-back valve is triggered to release/produce its sucking force with a sufficient delay time resulting from the sucking-back speed controller.