Underfill Air Vent for Flipchip BGA

Abstract

The invention relates to a system for assembling a flip chip assembly. An underfill resin is dispensed at multiple semiconductor die edges such that vacuum suction provided at a substrate through hole located beneath a stage enables spread of underfill resin from each edge simultaneously for quicker spread and reduction of voids. The excess underfill resin suctioned through the through hole on the underside of the semiconductor die is attracted to reusable tape. The attracted underfill resin is cleaned from a rotating head mechanism by a cleaning pad positioned beneath a lower surface of the head.

1 . (canceled) 
   
   
       2 . A system for assembling a flip chip assembly comprising:
 a flip chip having a semiconductor die with a top surface and a bottom surface, wherein the bottom surface is in physical communication with a machine stage;   an underfill resin, wherein the underfill resin is dispensed in a continuous manner at all peripheral edges of the semiconductor die by a nozzle;   a substrate through hole positioned on the bottom surface of the semiconductor die, wherein the through hole is not capped by solder resist and the through hole provides an electrical route and thermal conduction path;   an air vent in physical communication with the substrate through hole and a vacuum suction means for using suction force to enable the underfill to spread on all peripheral edges simultaneously,   wherein the machine stage further comprises a rotary head mechanism having a reusable tape, wherein the rotary head mechanism moves the reusable tape to remove excess resin protruding from the substrate through hole.