Probe tip design applied in a flip chip packaging process

Abstract

The present invention provides a novel probe tip suited for flip-chip packaging process. The probe tip comprises a needle body; and a stop cylinder having a recess for fittingly accommodating the needle body therein, the needle body being electrically connected to the stop cylinder via a resilient conductive material. The stop cylinder has an annual flat bottom surrounding the needle body for pressing a protruding probe mark on a metal pad scratched by the needle body.

1 . A probe tip for flip-chip packaging process, the probe tip comprising: 
 a needle body; and    a stop cylinder having a recess for accommodating the needle body therein, the needle body being electrically connected to the stop cylinder via a resilient conductive material;    wherein the stop cylinder has an annual flat bottom surrounding the needle body for pressing a protruding probe mark on a metal pad scratched by the needle body.    
     
     
         2 . The probe tip for flip-chip packaging process of  claim 1  wherein the metal pad is made of aluminum or copper and is formed on a chip.  
     
     
         3 . The probe tip for flip-chip packaging process of  claim 1  wherein the needle body protrudes from the bottom of the stop cylinder by at least 1 micron.  
     
     
         4 . The probe tip for flip-chip packaging process of  claim 1  wherein the resilient conductive material is conductive glue.  
     
     
         5 . The probe tip for flip-chip packaging process of claimed wherein the annual flat bottom has a width of about 20 microns to 30 microns.  
     
     
         6 . A flip-chip packaging process comprising: 
 providing a chip having thereon at least one metal pad surface;    providing a probe tip comprising a needle body and a stop cylinder having a recess for accommodating the needle body therein, the needle body being electrically connected to the stop cylinder via a resilient conductive material;    laterally moving the needle body of the probe tip to scratch a portion of the metal pad surface so as to form a protruding probe mark thereon;    pressing the protruding probe mark to a predetermined height with the stop cylinder;    forming a under bump metallurgy (UBM) over the metal pad surface; and    forming a bump over the UBM.    
     
     
         7 . The flip-chip packaging process of  claim 6  wherein the predetermined height is below 2 microns.  
     
     
         8 . The flip-chip packaging process of  claim 6  wherein the predetermined height is below 1 microns.  
     
     
         9 . The flip-chip packaging process of  claim 6  wherein the bump is solder bump.  
     
     
         10 . The flip-chip packaging process of  claim 6  wherein the metal pad is made of aluminum or copper and is formed on a chip.  
     
     
         11 . The flip-chip packaging process of  claim 6  wherein the needle body protrudes from the bottom of the stop cylinder by at least 1 micron.  
     
     
         12 . The flip-chip packaging process of  claim 6  wherein the resilient conductive material is conductive glue.  
     
     
         13 . The flip-chip packaging process of  claim 6  wherein the annual flat bottom has a width of about 20 microns to 30 microns.