Method of forming surface protrusions on an article and the article with the protrusions attached

Abstract

A method of forming surface protrusions on an article, and the article with the protrusions attached. The article may be an Integrated Circuit (IC) chip, a test probe for the IC chip or any suitable substrate or nanostructure. The surface protrusions are electroplated to a template or mold wafer, transferred to the article and easily separated from the template wafer. Thus, the attached protrusions may be, e.g., micro-bumps or micro pillars on an IC chip or substrate, test probes on a probe head, or one or more cantilevered membranes in a micro-machine or micro-sensor or other micro-electro-mechanical systems (MEMS) formed without undercutting the MEMS structure.

What is claimed is: 
     
         1 . An Integrated Circuit (IC) including a micro-electro-mechanical systems (MEMS) structure, said comprising:
 a semiconductor substrate;   circuits formed on said substrate;   at least one circuit including at least one attach pad connected to said at least one circuit; and   a cantilevered membrane soldered to said at least one attach pad.   
     
     
         2 . An IC including a MEMS as in  claim 1 , wherein said cantilevered membrane comprises:
 a base layer soldered to an attach pad;   a conductive layer, said base layer being electroplated to said base layer, said conductive layer extending beyond said base layer and forming said cantilevered membrane; and   a capping layer, said conductive layer being electroplated to said capping layer.   
     
     
         3 . An IC including a MEMS as in  claim 2 , wherein said cantilevered membrane has a first pyramidal shaped tip above said attach pad and at least one second pyramidal shaped tip on said cantilevered membrane. 
     
     
         4 . An IC including a MEMS as in  claim 3 , wherein said first pyramidal shaped tip is smaller than said second pyramidal shaped tip, said base layer is nickel, said conductive layer is copper and said capping layer is nickel.