Directing the flow of underfill materials using magnetic particles

Abstract

Electronic devices and methods for fabricating electronic devices are described. One method includes providing a substrate and a die, and coupling the die to the substrate, wherein a gap remains between the die and the substrate. The method also includes placing an underfill material on the substrate and delivering at least part of the underfill material into the gap. The method also includes controlling the flow of the underfill material in the gap using magnetic force. Other embodiments are described and claimed.

1 - 15 . (canceled) 
     
     
         16 . An assembly comprising:
 a first body;   a second body;   the first body electrically coupled to the second body through a plurality of electrically conductive bumps positioned between the first body and the second body;   a gap between the first body and the second body; and   an underfill material positioned in the gap between the first body and the second body, the underfill material comprising a polymer and magnetic particles;   an open region extending laterally outward from the gap on the second body on four sides of the gap, wherein the open region is not covered by the first body;   the underfill material extending from the gap into the open region on the second body on the four sides of the gap, wherein the underfill material extends no greater than 1 mm into the open region on the second body on each of the four sides.   
     
     
         17 . A system comprising:
 a central processing unit including the assembly of  claim 16 ;   a memory electrically coupled to the central processing unit;   an input device electrically coupled to the central processing unit;   an output device electrically coupled to the central processing unit; and   a video controller electrically coupled to the central processing unit.   
     
     
         18 . The assembly of  claim 16 , wherein the underfill material comprises a polymer epoxy, magnetic particles, and silicon oxide particles. 
     
     
         19 . The assembly of  claim 16 , wherein the first body comprises a semiconductor die and the second body comprises a substrate.