Abstract:
A pulse-operated laser emitting device for cutting a sapphire substrate includes a picoseconds laser for emitting a laser beam and a collimator lens positioned in a path of the laser beam and which cuts the sapphire substrate cleanly so as not to require any grinding or polishing processes afterwards.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to sapphire machining, and particularly to a device to cut a sapphire substrate. 
         [0003]    2. Description of Related Art 
         [0004]    Sapphires have excellent mechanical and optical properties and therefore are used in electronic devices. For example, the sapphire has high scratch and abrasion resistance and therefore can be used as a cover glass of a lens module or a front cover of a cell phone to protect the lens module or the cell phone from being scratched or abraded. However, as the sapphire has a high hardness (9 Mohs scale), it is difficult to cut the sapphire to obtain desired shapes and sizes. Micro-cracks may be introduced by a cutting process and therefore grinding and polishing processes are required, which decreases efficiency of production. 
         [0005]    Therefore, it is desirable to provide a device for cutting sapphire that can overcome the above-mentioned problems. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. 
           [0007]      FIG. 1  is a schematic view of a device for cutting a sapphire substrate, according to an embodiment. 
           [0008]      FIG. 2  is a schematic view of parts of the device of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    Embodiments of the present disclosure will be described with reference to the drawings. 
         [0010]      FIGS. 1 and 2  show a device  10  for cutting a sapphire substrate  20 , according to an embodiment. The device  10  includes a picoseconds laser  100  and a collimator lens  200 . The picoseconds laser  100  emits a laser beam  110  having a pulse width shorter than 15 picoseconds. The collimator lens  200  is positioned in a path of the laser beam  110  to collimate the laser beam  110  to produce a collimated laser beam  120  for cutting the sapphire substrate  20 . 
         [0011]    The pulse width of the laser beam  110  is short enough to reduce thermal reaction between the laser beam  120  and the sapphire substrate  20 . As such, hot-melt problems conventionally happening to a cut surface are avoided and smoothness of the cut surface is improved. As a consequence, grinding and polishing processes are not needed any more and efficiency is increased. In addition, as the picoseconds laser  100  has a higher repetition frequency, as compared with conventional lasers, cutting speed can therefore be increased, further improving the efficiency. 
         [0012]    The picoseconds laser  100  can be an ultrasonic, green, or near-infrared laser. A wavelength of the laser beam  110  can be about 355 nm, 343 nm, 266 nm, 532 nm, 515 nm, 1030 nm, or 1064 nm. The repetition frequency of the laser beam  110  can be adjusted. 
         [0013]    The device  10  also includes a shell  300 . The shell  300  defines a receiving space  310 , which has an opening  312 . The picoseconds laser  100  is received in the receiving space  310  and is aimed at the opening  312 . The collimator lens  200  seals the opening  312  and collimates the laser beam  110 . 
         [0014]    The device  10  further includes a worktable  400 . The worktable  400  includes a table  410 , a mechanical arm  420 , and a controller  430 . The table  410  supports the sapphire substrate  20 . The table  410  defines a slit  412 . The sapphire substrate  20  is positioned across the slit  412 . The mechanical arm  420  is positioned above the table  410  and can move the shell  300 . The collimated laser beam  120  passes through the slit  412 . The controller  430  controls the mechanical arm  420  to drive the shell  300  to move such that the collimated moves along a predetermined trajectory and the picoseconds laser  100  is switched on and switched off to cut the sapphire substrate  20  as desired. In this embodiment, the predetermined trajectory coincides with the slit  412  to protect the table  410  from laser damage. 
         [0015]    The table  410  also defines a circular hole  414 . The circular hole  414  communicates with the slit  412  or in other embodiments is separated from the slit  412 . The sapphire substrate  20  can be positioned to cover the circular hole. The predetermined trajectory can be a circle falling within the circular hole  414 . That is, the device  10  can cut a circular piece (not shown) from the sapphire substrate  20  without cutting the table  410 . 
         [0016]    It will be understood that the above particular embodiments are shown and described by way of illustration only. The principles and the features of the present disclosure may be employed in various and numerous embodiments thereof without departing from the scope of the disclosure. The above-described embodiments illustrate the possible scope of the disclosure but do not restrict the scope of the disclosure.