Abstract:
A brittle material breaking apparatus using a lifting mechanism to lift/lower a carrier wherein the lifting mechanism is controlled to lift the carrier for holding the brittle material for breaking, and then to lower the carrier from the brittle material to a distance for enabling the brittle material to be shifted to a next scribe line for further breaking, preventing the occurrence of friction between the brittle material and the carrier and the production of static electricity and micro particles and, improving the breaking quality. The brittle material breaking apparatus further includes a stroke fine adjustment mechanism adapted to adjust the stroke of the breaking-cutter relative to the brittle material.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to an apparatus for breaking of brittle material and, more specifically, to an apparatus adapted to break semiconductor wafers along scribe lines scribed on the semiconductor wafers. 
   2. Description of Related Art 
   Various equipments are requisite in a foundry during the fabrication of semiconductor wafers. In order to improve the precision and reduce the production of micro particles, apparatus for scribing and/or breaking semiconductor wafers must be maintained clean. 
   When breaking a semiconductor wafer according to a conventional manufacturing process, the semiconductor wafer is adhered to a thin film and then scribed with transverse and longitudinal scribe lines on the surface, and then the scribed semiconductor wafer is put on the wafer breaking apparatus, and then the breaking-cutter of the wafer breaking apparatus is lifted to break the semiconductor wafer at one of the scribe lines, and then the semiconductor wafer is shifted to a predetermined distance for enabling the breaking-cutter to break the semiconductor wafer at a second scribe line. This breaking action is repeated again and again to complete breaking of the semiconductor wafer. 
   During the aforesaid conventional semiconductor wafer breaking operation, the semiconductor wafer is directly carried on and maintained in contact with the semiconductor wafer breaking apparatus. When shifting the semiconductor wafer, friction is produced between the bottom surface of the thin film at the semiconductor wafer and the top side of the semiconductor wafer breaking apparatus. This friction increases the risk of scratching damage to the semiconductor wafer and the possibility of the production of static electricity or micro particles, affecting the semiconductor wafer breaking quality. U.S. Pat. No. 5,820,006, entitled “Apparatus for scribing and/or breaking semiconductor wafers” is an example of the aforesaid prior art design. 
   SUMMARY OF THE INVENTION 
   The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a brittle material breaking apparatus, which prevents friction between the brittle material and the brittle material breaking apparatus, improving the breaking quality. It is another object of the present invention to provide a brittle material breaking apparatus, which has means for adjusting of the stroke of the breaking-cutter relative to the brittle material. 
   To achieve these and other objects of the present invention, the brittle material breaking apparatus is adapted to break a brittle material that has been scribed with a plurality of scribe lines thereon, and the apparatus comprising a base frame, a lifting mechanism, and a breaking-cutter module. The base frame comprises two parallel sliding grooves extended in vertical direction. The lifting mechanism comprises two parallel sliding rails, a transverse plate, and a driving module. The sliding rails extended in vertical direction and adapted to slide along the sliding grooves respectively, the transverse plate affixed between the sliding rails, and the driving module adapted to drive the transverse plate and the sliding rails sliding along the sliding grooves vertically. The breaking-cutter module comprises a carrier, a driving mechanism, and a cutter assembly. The carrier mounted between the sliding rails of the lifting mechanism, the carrier comprising a central cutter slot, the driving mechanism mounted on the carrier, and the cutter assembly comprising a cutter holder, and a breaking-cutter. The cutter holder mounted on the driving mechanism and adapted to be lifted by the driving mechanism, and the breaking-cutter mounted on the cutter holder and adapted to be protruded through the central cutter slot to break one of the scribe lines of the brittle material upon upward movement of the cutter holder by the driving mechanism of the breaking-cutter module. 
   When wishing to break the brittle material, the apparatus is set below the brittle material, and then the lifting mechanism is controlled to lift the carrier for enabling the carrier to hold the brittle material by vacuum for breaking, and then the cutter holder is slid vertically upwards to lift the breaking-cutter through the central cutter slot of the carrier to force the cutting edge against one of the scribe lines of the brittle material. After the breaking of one of the scribe lines of the brittle material, the lifting mechanism is controlled to lower the carrier from the brittle material, and then the brittle material is shifted to a next scribe line for breaking, and then the lifting mechanism is controlled to lift the carrier again, for enabling the breaking-cutter module to break the brittle material again. 
   When shifting the brittle material from one scribe line to another during the aforesaid breaking-cutting operation, the lifting mechanism is controlled to lower the carrier from the brittle material at first, therefore shifting the brittle material from one scribe line to another does not cause friction between the brittle material breaking apparatus and the brittle material. 
   The driving mechanism of the breaking-cutter module comprises a fixed member, a movable member, and an air cylinder, the fixed member fixedly mounted on the carrier, the movable member coupled to and adapted to slide along the fixed member, and the air cylinder mounted on the movable member. The breaking-cutter module further comprises a stroke fine adjustment mechanism installed in the carrier. The stroke fine adjustment mechanism comprises a cam shaft, and a motor, the cam shaft coupled to the movable member of the driving mechanism of the breaking-cutter module, and the motor adapted to rotate the cam shaft and to further adjust vertical moving distance of the movable member relative to the fixed member so as to relatively adjust the moving distance of the cutter holder with the air cylinder relative to the brittle material. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded view of a brittle material breaking apparatus according to the present invention. 
       FIG. 2  is a perspective assembly view of the brittle material breaking apparatus according to the present invention. 
       FIG. 3  is an applied view of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 3  is an applied view of the present invention for breaking of a brittle material  9  that has been scribed with a plurality of scribe lines  91  thereon. The brittle material  9  is adhered to a thin film carried on a rotary table  6  and maintained at a predetermined height. According to this embodiment, the brittle material  9  is a semiconductor wafer. The rotary table  6  is carried on a sliding table assembly  82 . The sliding table assembly  82  comprises a sliding rail unit  820  affixed to a flat base plate  5  and extended in longitudinal direction, and a sliding block unit  821  affixed to the bottom side of the rotary table  6  and slidably coupled to the sliding rail unit  820  for enabling the brittle material  9  and the rotary table  6  to be slid with the sliding block unit  821  along the sliding rail unit  820  so that the brittle material  9  can be broken by the apparatus of the present invention. 
   Referring to  FIGS. 1 and 2 , the brittle material breaking apparatus of the present invention is vertically spaced below the brittle material  9 , comprising a base frame  1 , a lifting mechanism  2 , and a breaking-cutter module  3 . The base frame  1  has two vertical sliding grooves  11  extended in vertical direction and arranged in parallel. 
   The lifting mechanism  2  comprises a driving module  21 , two parallel vertical sliding rails  22 , and a transverse plate  23 . The driving module  21  comprises a motor  211 , a cam shaft  212 , and a cam shaft linker  24 . The cam shaft linker  24  is fixedly mounted on the transverse plate  23 , having a mating slot  241  adapted to support the cam shaft  212 . The cam shaft  212  is an eccentric shaft rotated in the mating slot  241  of the cam shaft linker  24  to drive the cam shaft linker  24  and the transverse plate  23  alternatively up and down. The transverse plate  23  is fixedly fastened between the respective lower parts of the vertical sliding rails  22 . The vertical sliding rails  22  are respectively coupled to and slidably along the vertical sliding grooves  11 . The motor  211  of the driving module  21  is fixedly mounted on the base frame  1 , and adapted to rotate the cam shaft  212  by the eccentric function, causing the vertical sliding rails  22  to be slid with the transverse plate  23  vertically along the vertical sliding grooves  11 . As shown in  FIG. 1 , the base frame  1  can be provided between the motor  211  and the two vertical sliding rails  22 , the motor  211  can be directly affixed to the base frame  1 , the transverse plate  23  and the two vertical sliding grooves  11  can respectively be disposed at the other side of the vertical sliding rails  22  and the other side of the base frame  1 . 
   The breaking-cutter module  3  comprises a driving mechanism  31 , a carrier  32 , and a cutter assembly  33 . The driving mechanism  31  further comprises a fixed member  311 , a movable member  312 , and an air cylinder  313 . The carrier  32  further comprises a carrier base  323  and a vacuum base  322 . The cutter assembly  33  further comprises a cutter holder  332 , and a breaking-cutter  331 . 
   The fixed member  311  of the driving mechanism  31  is mounted on the carrier base  323  of the carrier  32 . The movable member  312  of the driving mechanism  31  is slidably mounted on the fixed member  311 . The air cylinder  313  of the driving mechanism  31  is mounted on the movable member  312 . The cutter holder  332  of the cutter assembly  33  is coupled to the air cylinder  313  of the driving mechanism  31 . The breaking-cutter  331  is mounted on the cutter holder  332 . The vacuum base  322  of the carrier  32  is mounted on the carrier base  323 . The carrier base  323  is mounted between the respective upper parts of the two vertical sliding rails  22  of the lifting mechanism  2 . The vacuum base  322  has a central cutter slot  321  on the middle. 
   When wishing to break the brittle material  9 , the lifting mechanism  2  is controlled to lift the carrier  32  for enabling the vacuum base  322  of the carrier  32  to hold the brittle material  9  for breaking, and then the air cylinder  313  of the driving mechanism  31  is operated to move the cutter holder  332  vertically upwards so as to lift the breaking-cutter  331  protruded through the central cutter slot  321  of the vacuum base  322  over the top side of the vacuum base  322  and to force the cutting edge of the breaking-cutter  331  against one of the scribe lines  91  of the brittle material  9 . After the aforesaid action, the lifting mechanism  2  is controlled to lower the carrier  32 , and then the rotary table  6  is slid along the sliding block unit  821  to let the next scribe line  91  of the brittle material  9  be aimed at the cutting edge of the breaking-cutter  331 , and then the lifting mechanism  2  is controlled to lift the carrier  32  again, for enabling the brittle material  9  to be hold on the vacuum base  322  of the carrier  32  again, and then the air cylinder  313  of the driving mechanism  31  is controlled to lift the breaking-cutter  331  protruded through the central cutter slot  321  of the vacuum base  322  over the top side of the vacuum base  322  again, and to force the cutting edge of the breaking-cutter  331  against the second scribe line  91  of the brittle material  9 , and thus the second breaking-cutting action of the brittle material  9  is done. 
   The aforesaid breaking-cutting action is repeated again and again to complete the breaking operation of the brittle material  9 . Because the scribe lines  91  of the brittle material  9  include transverse scribe lines and longitudinal scribe lines, the rotary table  6  (see  FIG. 3 ) can be operated to rotate the brittle material  9  through  900  angle, and then the aforesaid breaking-cutting action is repeated again and again to complete transverse and longitudinal breaking operation of the brittle material  9 . 
   When shifting the brittle material  9  from one scribe line to another during the aforesaid breaking-cutting operation, the lifting mechanism  2  is controlled to lower the carrier  32  at first, at this time the brittle material  9  is maintained at the original elevation, keeping the brittle material  9  spaced above the carrier  32  and the vacuum base  322  at the predetermined height, and therefore no direct friction is produced between the brittle material  9  and the vacuum base  322  during shifting of the brittle material  9 . Because the brittle material  9  is kept away from the vacuum base  322  during shifting, shifting the brittle material  9  from one scribe line  91  to another does not cause a scratching damage and friction loss to the brittle material  9 , or produce static electricity or particles due to friction. Therefore, the present invention improves the quality of the breaking of brittle materials. Further, the motor  211  of the aforesaid lifting mechanism  2  can be computerized to achieve precision positioning. 
   A displacement sensor  7  may be mounted on the base frame  1  and the transverse plate  23  of the lifting mechanism  2  to detect the sliding distance of the lifting mechanism  2  relative to the base frame  1 . Further, two porous ceramic plates  324  are mounted on the vacuum base  322  of the carrier  32 . The porous ceramic plates  324  each have a plurality of capillaries. After putting of the brittle material  9  to be broken on the vacuum base  322 , air is drawn away from the capillaries of the porous ceramic plates  324 , thereby causing the brittle material  9  to be smoothly and positively secured to the vacuum base  322  by a vacuum force. 
   The breaking-cutting module  3  further comprises a stroke fine adjustment mechanism  34  mounted on the carrier base  323  of the carrier  32 . The stroke fine adjustment mechanism  34  is comprised of a motor  341  and a cam shaft  342 . The cam shaft  342  is a eccentric and coupled to the movable member  312  of the aforesaid driving mechanism  31 . The motion between the cam shaft  342  and the movable member  312  is similar to the motion between the cam shaft  212  of the aforesaid lifting mechanism  2  and the cam shaft linker  24 . The motor  341  is fixedly mounted on the carrier base  323  and controlled to rotate the cam shaft  342 , adjusting the vertically slidably distance of the movable member  312  on the fixed member  311 , i.e., rotating the cam shaft  342  causes a movement of the movable member  312  of the driving mechanism  31  relative to the fixed member  311 , and the air cylinder  313  as well as the cutter holder  332  are followed. At this time, the stroke (moving distance) of the breaking-cutter  331  of the cutter assembly  33  relative to the brittle material  9  is relatively adjusted. 
   Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.