Patent ID: 6514569
Filing Date: 2003-02-04
Classification: B05C,F04B,G01F,H05K

Abstract:
A method of dispensing viscous material onto a substrate using a dispensing system having a dispensing pump, the dispensing pump having at least three dispensing chambers each having a piston movable within the dispensing chamber to draw the viscous material into the dispensing chamber and to dispense the viscous material from the dispensing chamber, the method comprising steps of:loading the substrate into the dispensing system; positioning the dispensing pump over the substrate; moving one of the pistons in one of the dispensing chambers in a first direction for a first predetermined movement time to a retracted position to draw viscous material into the one of the dispensing chambers; maintaining the one of the pistons at the retracted position for a first predetermined dwell time; moving the one of the pistons in a second direction, opposite the first direction, for a second predetermined movement time to an extended position to dispense the viscous material from the one of the dispensing chambers, wherein the second predetermined movement time is substantially the same as the first predetermined movement time.