Wafer dicing device and method

Abstract

Methods and devices for cutting workpieces, which include a laser adapted to at least partially cut a workpiece, are described. The workpiece is a wafer having a plurality dies each with an integrated circuit. A mechanical cutter follows the laser and engages the workpiece. An embodiment of the mechanical cutter includes a cutting blade adapted to complete a cut through a workpiece. A method includes a two-pass cutting procedure. The first pass is made by a laser, which scribes the workpiece. The second pass is made by the mechanical cutter. In an embodiment, the mechanical cutter follows the scribe created by the laser. In an embodiment, the workpiece is supported by a table. The workpiece moves relative to the laser and the mechanical cutter.

The invention claimed is:  
     
         1 . A wafer having a top surface and a body, comprising: 
 a first state wherein the top surface is uncut;    a second state wherein the top surface has a laser cut partially into the body; and    a third state wherein a further cut extends completely through the body of the wafer.    
     
     
         2 . The wafer of  claim 1 , wherein the laser cut has a depth from the top surface into the body of about 25 micrometers to about 50 micrometers.  
     
     
         3 . The wafer of  claim 1 , wherein the wafer has a thickness of greater than about five millimeters.  
     
     
         4 . The wafer of  claim 1 , wherein the body includes a saw street where the laser cut is positioned in the second state.  
     
     
         5 . The wafer of  claim 4 , wherein the further cut is positioned in the saw street in the third state.  
     
     
         6 . The wafer of  claim 1 , wherein the further cut is adapted to be formed by a cutting blade.  
     
     
         7 . The wafer of  claim 1 , wherein the further cut is adapted to be formed by a nickel-diamond cutting surface.  
     
     
         8 . A method for dicing workpieces, comprising: 
 scribing a workpiece with a laser; and    completely cutting through the workpiece along the scribe with a mechanical cutter.    
     
     
         9 . The method of  claim 8 , wherein scribing includes setting the laser to have an average power of about 300 watts and a maximum refresh rate of 3,000 Hz.  
     
     
         10 . The method of  claim 8 , wherein completely cutting includes engaging the wafer at the scribe with a saw.  
     
     
         11 . The method of  claim 10 , wherein engaging the wafer includes sawing the wafer with a nickle-diamond cutting surface.  
     
     
         12 . The method of  claim 8 , wherein scribing includes scribing the wafer with a yttrium-aluminum-garnet (YAG) laser.  
     
     
         13 . A method for dicing workpieces, comprising: 
 scribing a workpiece with a laser; and    completely cutting through the workpiece along the scribe with a mechanical cutter, wherein the laser and the mechanical cutter simultaneously contact the workpiece.    
     
     
         14 . The method of  claim 13 , wherein completely cutting includes fixing the mechanical cutter at a set distance behind the laser.  
     
     
         15 . The method of  claim 14 , wherein scribing includes setting the laser to have an average power of about 300 watts and a maximum refresh rate of 3,000 Hz.  
     
     
         16 . A method for dicing workpieces, comprising: 
 moving a workpiece relative to a laser;    scribing a workpiece with the laser; and    completely cutting through the workpiece along the scribe with a mechanical cutter.    
     
     
         17 . The method of  claim 16 , wherein moving includes moving the workpiece at a speed of 120 mm/sec.  
     
     
         18 . The method of  claim 17 , wherein scribing includes setting the laser to have an average power of about 300 watts and a maximum refresh rate of 3,000 Hz.  
     
     
         19 . The method of  claim 16 , wherein moving a workpiece relative to a laser includes holding the laser stationary.  
     
     
         20 . The method of  claim 16 , wherein completely cutting through the workpiece includes cutting the workpiece with a nickel coated blade.