Methods for applying an underfill with vacuum assistance. The method may include dispensing the underfill onto a substrate proximate to at least one exterior edge of an electronic device attached to the substrate. A space between the electronic device and the substrate is evacuated through at least one gap in the underfill. The method further includes heating the underfill to cause the underfill to flow into the space. Because a vacuum condition is supplied in the open portion of the space before flow is initiated, the incidence of underfill voiding is lowered.