Method of disposing conductive bumps onto a semiconductor device and semiconductor devices so formed

Abstract

A method of forming conductive structures on the contact pads of a substrate, such as a semiconductor die or a printed circuit board. A solder mask is secured to an active surface of the substrate. Apertures through the solder mask are aligned with contact pads on the substrate. The apertures may be preformed or formed after a layer of the material of which the solder mask is comprised has been disposed on the substrate. Conductive material is disposed in and shaped by the apertures of the solder mask to form conductive structures in communication with the contact pads exposed to the apertures. Sides of the conductive structures are exposed through the solder mask, either by removing the solder mask from the substrate or by reducing the thickness of the solder mask. The present invention also includes semiconductor devices formed during different stages of the method of the present invention.

1 . A method for forming at least one conductive structure in communication with at least one contact pad of a semiconductor device substrate, comprising: 
 forming a layer of mask material having a thickness that corresponds substantially to a desired height of the at least one conductive structure, the layer configured to be positioned over the substrate;    forming at least one aperture through the layer to expose at least a portion of the at least one contact pad;    introducing conductive material into the at least one aperture to form the at least one conductive structure to substantially the desired height; and    partially exposing a lateral periphery of the at least one conductive structure through the layer.    
   
   
       2 . The method of  claim 1 , further comprising: 
 positioning the layer over the substrate.    
   
   
       3 . The method of  claim 2 , further comprising: 
 securing the layer to the substrate.    
   
   
       4 . The method of  claim 2 , wherein forming the at least one aperture is effected before positioning the layer over the substrate.  
   
   
       5 . The method of  claim 2 , wherein forming the at least one aperture is effected after the layer has been secured to the substrate.  
   
   
       6 . The method of  claim 1 , wherein forming the layer is effected on the substrate.  
   
   
       7 . The method of  claim 1 , further comprising: 
 bonding the conductive material within the at least one aperture to at least the portion of the at least one contact pad.    
   
   
       8 . The method of  claim 1 , wherein partially exposing comprises reducing a thickness of the layer of mask material.  
   
   
       9 . The method of  claim 8 , wherein reducing the thickness of the layer of mask material comprises shrinking the layer of mask material.  
   
   
       10 . The method of  claim 9 , wherein shrinking comprises exposing the mask material to radiation, a shrinking agent, or a plasma.  
   
   
       11 . The method of  claim 8 , wherein reducing the thickness of the layer of mask material comprises removing mask material.  
   
   
       12 . A method for forming a solder mask, comprising: 
 applying a solder mask material to a contact pad-bearing surface of a substrate to form a layer of reducible thickness, the layer having an initial thickness that corresponds substantially to a desired height of at least one conductive structure to be formed over the substrate; and    forming at least one aperture through the layer in a location that corresponds to at least one contact pad carried by the substrate to expose at least a portion of the at least one contact pad.    
   
   
       13 . The method of  claim 12 , wherein applying comprises applying unconsolidated material to the contact pad-bearing surface of the substrate.  
   
   
       14 . The method of  claim 13 , further comprising at least partially consolidating the unconsolidated material.  
   
   
       15 . The method of  claim 14 , wherein at least partially consolidating includes forming the at least one aperture.  
   
   
       16 . The method of  claim 12 , wherein forming the at least one aperture comprises removing solder mask material from the layer.