US2003226830A1PendingUtilityA1

Scribing sapphire substrates with a solid state UV laser

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Assignee: NEW WAVE RESPriority: Jun 10, 2002Filed: Feb 11, 2003Published: Dec 11, 2003
Est. expiryJun 10, 2022(expired)· nominal 20-yr term from priority
Inventors:Kuo-Ching LiuPei Hsien FangDan DereJenn LiuJih-Chuang HuangAntonio LuceroScott PinkhamSteven OltroggeDuane Middlebusher
H10P 54/00H10H 20/01B23K 26/40B23K 26/032B23K 26/073B28D 5/0011H01S 5/0201H01S 5/0213H01S 5/32341B23K 26/364B23K 26/0622B23K 2103/36B23K 2103/50B23K 2101/40
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Claims

Abstract

A process and system scribe sapphire substrates, by performing the steps of mounting a sapphire substrate, carrying an array of integrated device die, on a stage such as a movable X-Y stage including a vacuum chuck; and directing UV pulses of laser energy directed at a surface of the sapphire substrate using a solid-state laser. The pulses of laser energy have a wavelength below about 560 nanometers, and preferably between about 150 in 560 nanometers. In addition, energy density, spot size, and pulse duration are established at levels sufficient to induce ablation of sapphire. Control of the system, such as by moving the stage with a stationary beam path for the pulses, causes the pulses to contact the sapphire substrate in a scribe pattern at a rate of motion causing overlap of successive pulses sufficient to cut scribe lines in the sapphire substrate.

Claims

exact text as granted — not AI-modified
What is claimed is:  
     
         1 . A system for scribing a sapphire substrate, comprising: 
 a laser generating pulses of laser energy in a wavelength less than about 560 nanometers, with a pulse duration less than about 30 nanoseconds at a repetition rate of greater than 5 kHz;    a stage adapted to support, and move, a sapphire substrate;    optics directing the pulses to impact a sapphire substrate mounted on the stage; and    a control system coupled to the solid state laser and the stage, the control system controlling the laser and stage, and causing the pulses to impact the sapphire substrate in a scribe pattern at a rate of motion causing overlap of successive pulses sufficient to cut scribe lines in the sapphire substrate.    
     
     
         2 . The system of  claim 1 , wherein the control system controls a rate of motion of the stage, causing overlap of successive pulses.  
     
     
         3 . The system of  claim 1 , including an edge detection system which detects edges of a substrate mounting on the stage during movement of the stage;  
     
     
         4 . The system of  claim 1 , including a debris exhaust system.  
     
     
         5 . The system of  claim 1 , wherein the control system includes logic to set up a scribe pattern.  
     
     
         6 . The system of  claim 1 , wherein the stage includes a vacuum chuck.  
     
     
         7 . The system of  claim 1 , including a video system for viewing a substrate mounted on the stage.  
     
     
         8 . The system of  claim 1 , wherein the control system includes logic to set up parameters including pulse repetition rate, pulse energy and stage speed.  
     
     
         9 . The system of  claim 1 , wherein the laser comprises a Q-switched Nd:YAG laser.  
     
     
         10 . The system of  claim 1 , wherein the laser comprises a Q-switched Nd:YVO 4  laser.  
     
     
         11 . The system of  claim 1 , wherein the laser comprises a diode pumped, Q-switched Nd:YVO 4  laser operating at a third harmonic wavelength of about 355 nanometers.  
     
     
         12 . The system of  claim 1 , wherein the laser comprises a diode pumped, Q-switched Nd:YAG laser operating at a third harmonic wavelength of about 355 nanometers.  
     
     
         13 . The system of  claim 1 , wherein the spot size is between 5 and 15 microns.  
     
     
         14 . The system of  claim 1 , wherein the control system controls a rate of motion of the stage, causing overlap of successive pulses, wherein the overlap is in a range from 50 to 99 percent.  
     
     
         15 . The system of  claim 1 , wherein the pulse rate is between about 10 kHz and 50 kHz.  
     
     
         16 . The system of  claim 1 , wherein said energy density is between about 10 and 100 joules per square centimeter, said pulse duration is between about 10 and 30 nanoseconds, and the spot size is between about 5 and 25 microns.  
     
     
         17 . The system of  claim 1 , wherein the sapphire substrate has a thickness, and the scribe lines are cut to a depth of more than about one half said thickness.  
     
     
         18 . The system of  claim 1 , including optics to linearly polarize the pulses.  
     
     
         19 . The system of  claim 1 , including optics to adjust polarization of the pulses.  
     
     
         20 . A system for scribing a sapphire substrate, comprising: 
 a Q-switched, solid state laser generating pulses of laser energy in a wavelength between about 150 and 560 nanometers, pulse duration less than about 30 nanoseconds and a spot size of less than 25 microns, at a repetition rate of greater than 10 kHz;    a stage adapted to support, and move, a sapphire substrate;    optics directing the pulses to impact a sapphire substrate mounted on the stage;    an edge detection system which detects edges of a substrate mounting on the stage during movement of the stage; and    a control system coupled to the solid state laser, the stage and the edge detection system, the control system controlling the laser and stage, and responsive to the edge detection system, and causing the pulses to impact the sapphire substrate in a scribe pattern at a rate of motion causing overlap of successive pulses sufficient to cut scribe lines in the sapphire substrate.    
     
     
         21 . The system of  claim 20 , including a debris exhaust system.  
     
     
         22 . The system of  claim 20 , wherein the control system includes logic to set up a scribe pattern.  
     
     
         23 . The system of  claim 20 , wherein the stage includes a vacuum chuck.  
     
     
         24 . The system of  claim 20 , including a video system for viewing a substrate mounted on the stage.  
     
     
         25 . The system of  claim 20 , wherein the control system includes logic to set up parameters including pulse repetition rate, pulse energy and stage speed.  
     
     
         26 . The system of  claim 20 , wherein the laser comprises a Q-switched Nd:YAG laser.  
     
     
         27 . The system of  claim 20 , wherein the laser comprises a Q-switched Nd:YVO 4  laser.  
     
     
         28 . The system of  claim 20 , wherein the laser comprises a diode pumped, Q-switched Nd:YAG laser operating at a third harmonic wavelength of about 355 nanometers.  
     
     
         29 . The system of  claim 20 , wherein the laser comprises a diode pumped, Q-switched Nd:YVO 4  laser operating at a third harmonic wavelength of about 355 nanometers.  
     
     
         30 . The system of  claim 20 , wherein the spot size is between 5 and 15 microns.  
     
     
         31 . The system of  claim 20 , wherein the overlap is in a range from 50 to 99 percent.  
     
     
         32 . The system of  claim 20 , wherein the pulse rate is between about 20 kHz and 50 kHz.  
     
     
         33 . The system of  claim 20 , wherein said energy density is between about 10 and 100 joules per square centimeter, said pulse duration is between about 10 and 30 nanoseconds, and the spot size is between about 5 and 25 microns.  
     
     
         34 . The system of  claim 20 , wherein the sapphire substrate has a thickness, and the scribe lines are cut to a depth of more than about one half said thickness.  
     
     
         35 . The system of  claim 20 , including optics to linearly polarize the pulses.  
     
     
         36 . The system of  claim 20 , including optics to adjust polarization of the pulses.

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