Patent Publication Number: US-2006014475-A1

Title: Grindstone tool

Description:
FIELD OF THE INVENTION  
      The present invention relates to a grindstone tool which has a grindstone such as resinoid grindstone manufactured by kneading abrasive grains with a bonding material, molding the kneaded product into a predetermined form and baking it and is used to perform a predetermined processing on a workpiece.  
     DESCRIPTION OF THE PRIOR ART  
      In the production process of a semiconductor device, a plurality of areas are sectioned by dividing lines called “streets” arranged in a lattice pattern on the front surface of a substantially disk-like semiconductor wafer, and a circuit such as IC or LSI is formed in each of the sectioned areas. After the back surface of this semiconductor wafer is ground to a predetermined thickness by a grinding machine, the semiconductor wafer is cut along the dividing lines to be divided into individual semiconductor chips.  
      A grinding stone is used to grind the back surface of the above semiconductor wafer, and a grindstone blade is also used to cut the semiconductor wafer along the dividing lines. For the above processing, grindstones having different characteristic properties according to processing purposes are used. As a grindstone used in the grinding stone and the grindstone blade is used a resinoid grindstone manufactured by kneading abrasive grains which differ according to the material of a workpiece with a bonding material, molding the kneaded product and baking it, as disclosed by JP-A2004-181575 and JP-A 8-224730.  
      Since the resinoid grindstone is manufactured by kneading abrasive grains with a bonding material, molding the kneaded product into a predetermined form and baking it as described above, its quality may vary depending upon production conditions such as the temperature of a kiln in the production process, the number of grindstones baked in the kiln, the position of the grindstone in the kiln, weather, etc. Therefore, the quality of the grindstone cannot be checked at the time when it is manufactured. Consequently, when the resinoid grindstone is broken or damages a workpiece during its use, it is difficult to find the cause of the damage.  
      Further, it is impossible to check the characteristic properties such as the thickness of a cutting edge, the length of a projecting edge of the blade, the size and density of abrasive grains of an electroformed grindstone blade mounted onto a base or a grinding stone mounted onto abase. Therefore, it is difficult to detect the cause of the damage of the grindstone blade or the grinding stone or the cause of a damage to the workpiece during its use.  
      Further, a user who uses a grindstone such as a resinoid grindstone and electroformed grindstone blade records information on the use time of the grindstone, the type of a processed workpiece, the abrasion of the grindstone, the amount of the residual grindstone, the life of the grindstone, the date when the grindstone has been used, the device used with the grindstone, the name of an operator who used the grindstone and the condition of a trouble for each grindstone. It is troublesome to store the use record of each grindstone, and it is difficult to record the above information surely.  
     SUMMARY OF THE INVENTION  
      It is an object of the present invention to provide a grindstone tool, which enables the checking of the characteristic properties such as production conditions of a grindstone after use and the recording of the use record of the grindstone.  
      According to the present invention, the above object can be attained by a grindstone tool for performing predetermined processing on a workpiece, wherein  
      a radio IC tag from, and to, which information can be read, and written, without contact is embedded in the grindstone tool.  
      The above grindstone tool has resinoid grindstone manufactured by kneading abrasive grains with a bonding material, molding the kneaded product and baking it, and the radio IC tag is embedded in the resinoid grindstone. The above radio IC tag is embedded in the unused area of the grindstone.  
      The above grindstone tool comprises a base and a grindstone mounted on the base, and the radio IC tag is embedded in the base.  
      Data on the characteristic properties of the grindstone are recorded in the above radio IC tag. The use record of the grindstone is recorded in the above radio IC tag.  
      Since the radio IC tag from, and to, which information can be read, or written, without contact is embedded in the grindstone tool of the present invention, data on the characteristic properties of the grindstone and the use record of the grindstone stored in the radio IC tag can be read even after processing work is carried out by storing data on the characteristic properties of the grindstone and the use record of the grindstone in the radio IC tag. Therefore, when the grindstone tool is damaged or damages a workpiece during its use, the cause of the damage can be detected by reading and checking data on the characteristic properties and the use record of the grindstone stored in the radio IC tag. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of a grinding wheel having a grindstone as a grindstone tool according to a first embodiment of the present invention;  
       FIG. 2  is a perspective view of a grindstone composed of a resinoid grindstone constituting the grinding wheel shown in  FIG. 1 ;  
       FIG. 3  is a schematic constitution block diagram of a system for storing information in a radio IC tag embedded in the grindstone composed of a resinoid grindstone constituting the grinding wheel shown in  FIG. 1 ;  
       FIG. 4  is an exploded perspective view of the spindle unit of a cutting machine equipped with a cutting blade composed of a resinoid grindstone as a grindstone tool according to a second embodiment of the present invention;  
       FIG. 5  is a perspective view of a grinding wheel as a grindstone tool according to a third embodiment of the present invention; and  
       FIG. 6  is a perspective view of an electroformed grindstone blade as a grindstone tool according to a fourth embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Preferred embodiments of the present invention will be described in detail hereinunder with reference to the accompanying drawings.  
       FIG. 1  shows a grinding wheel having a grindstone as a grindstone tool according to a first embodiment of the present invention.  
      The grinding wheel  2  shown in  FIG. 1  is constituted by an annular grindstone base  21  andapluralityof grindstones  22  mounted on the undersurface of the grindstone base  21 . Each of the grindstones  22  is composed of a resinoid grindstone manufactured by kneading abrasive grains with a resin bonding material, molding the kneaded product into a rectangular parallelpiped form and baking it. One of the grindstones  22  each composed of a resinoid grindstone has a recessed portion  221  in the top end face that is an unused area as shown in  FIG. 2 , and a radio IC tag  3  is embedded in this recessed portion  221 . The radio IC tag  3  comprises a memory from, and to, which information can be read, and written, with no contact, by means of electric waves or electromagnetic waves.  
      Data on the characteristic properties of the resinoid grindstone are stored in the radio IC tag  3  embedded in the recessed portion  221  of the grindstone  22  at the point when it is embedded in the grindstone  22 . That is, as shown in  FIG. 3 , wave signals indicative of the characteristic properties of the resinoid grindstone are transmitted to the radio IC tag  3  embedded in the grinding wheel  22  from a controller  4  through an antenna  5 , which is a read/write head, to store data on the characteristic properties of the resinoid grindstone. The characteristic properties of the resinoid grindstone include manufacture data (the temperature of a kiln, baking time, the number of resinoid grindstones baked in the kiln, the position in the kiln, weather, etc.), grindstone components (type and density of abrasive grains, type of a bonding material, etc.), lot No., application purpose, shape, size, the outer diameter of the grindstone base  21 , and the number of grindstones mounted on the grindstone base  21 .  
      Since data on the characteristic properties of the resinoid grindstone are stored in the radio IC tag  3  embedded in the grindstone  22  as described above, even after grinding work is carried out by using the grinding wheel  2  mounting the grindstones  22 , data on the characteristic properties of the resinoid grindstone stored in the radio IC tag  3  can be read. Therefore, when the grindstone  22  is damaged or damages the workpiece during its use, the cause of the damage can be detected by reading and checking data on the characteristic properties of the resinoid grindstone stored in the radio IC tag  3 .  
      The use record of the grindstone such as the use time of the grindstone, the kind of the processed workpiece, the abrasion of the grindstone, the amount of the residual grindstone, the life of the grindstone, the date when the grindstone is used, the machine used with the grindstone, the name of an operator using the grindstone, the condition of a trouble, etc. can be stored in the radio IC tag  3  embedded in the grindstone  22  by a user or the control means of a grinding machine. Since the use record of the grindstone  22  is thus stored, when the grindstone  22  is damaged or damages the workpiece during its use, the cause of the damage can be detected by reading and checking the use record of the grindstone  22  stored in the radio IC tag  3 .  
      A description is subsequently given of a second embodiment of the present invention with reference to  FIG. 4 .  
      In the embodiment shown in  FIG. 4 , the present invention is applied to a grindstone blade  61  as a cutting tool mounted onto the spindle unit  6  of a cutting machine for cutting a semiconductor wafer along a predetermined dividing line. This grindstone blade  61  is composed of a resinoid grindstone manufactured by kneading abrasive grains with a resin bonding material, molding the kneaded product into an annular form and baking it. The annular grindstone blade  61  composed of a resinoid grindstone has a hole  611  in its inner peripheral portion that is an unused area, and the radio IC tag  3  is embedded in this hole  611 . The radio IC tag  3  is composed of a memory from and to which information can be read and written without contact by means of electric waves or electromagnetic waves as described above. Data on the characteristic properties such as the manufacture data, grindstone components, lot No., shape, size, etc. of the resinoid grindstone are stored in the radio IC tag  3  thus embedded in the grindstone blade  61 , as described above, at the time when it is embedded in the grindstone blade  61  or when it is mounted on the spindle unit of the cutting machine which will be described later.  
      The annular grindstone blade  61  which is composed of a resinoid grindstone embedded with the above radio IC tag  3  is mounted onto a mounter  63  fitted onto a rotary spindle  62  constituting the spindle unit  6  of the cutting machine. That is, the annular grindstone blade  61  is mounted onto the mounter  63  by fitting the annular grindstone blade  61  onto the cylindrical tool mounting portion  613  of the mounter  63 , fitting a sandwiching member  64  onto the mounting portion  613  and then, screwing a clamping ring  65  on a male screw portion formed on the mounter  63 .  
      Since data on the characteristic properties of the resinoid grindstone are stored in the radio IC tag  3  embedded in the grindstone blade  61  as described above, even after the grindstone blade  61  is mounted on the spindle unit  6  of the cutting machine to carry out cutting work, data on the characteristic properties of the resinoid grindstone stored in the radio IC tag  3  can be read. Therefore, when the grindstone blade  61  is damaged or damages the workpiece during its use, the cause of the damage can be detected by reading and checking data on the characteristic properties of the resinoid grindstone stored in the radio IC tag  3 .  
      By recording the use record of the grindstone blade  61  in the radio IC tag  3  embedded in the grindstone blade  61 , the cause of the damage can be detected by reading and checking the use record stored in the radio IC tag  3  when the grindstone blade  61  is damaged or damages the workpiece during its use.  
      A description is subsequently given of a third embodiment of the present invention with reference to  FIG. 5 . Since the grinding wheel  2  in the embodiment shown in  FIG. 5  is substantially the same as the grinding wheel  2  shown in  FIG. 1  except for the mounting position of the radio IC tag  3 , the same members as those of the grinding wheel  2  shown in  FIG. 1  are given the same reference symbols.  
      The grinding wheel  2  shown in  FIG. 5  is constituted by an annular grindstone base  21  and grindstones  22  mounted on the undersurface of the grindstone base  21 , like the embodiment shown in  FIG. 1 . Each of the grindstones  22  is composed of a resinoid grindstone manufactured by kneading abrasive grains with a resin bonding material, molding the kneaded product into a rectangular parallelepiped form and baking it. A recessed portion  211  is formed in the outer peripheral portion of the annular grindstone base  21  of the grinding wheel  2  in the embodiment shown in  FIG. 5 , and the radio IC tag  3  is embedded in this recessed portion  211  and molded with a synthetic resin or the like. The above data on the characteristic properties of the resinoid grindstones are stored and the above use record can be recorded in this radio IC tag  3 . Since the rotation balance of the grinding wheel  2  is slightly changed by embedding the radio IC tag  3  in the annular grindstone base  21 , it is desired that a balancing member  212  should be arranged at a position deviated by 180° from the position where the radio IC tag  3  is embedded in the annular grindstone base  21 .  
      A description is subsequently given of a fourth embodiment of the present invention with reference to  FIG. 6 .  
       FIG. 6  shows an electroformed grindstone blade  7  manufactured by fixing abrasive grains to the side face of a disk-like base  71  made of aluminum by nickel plating and removing the peripheral portion of the base  71  by etching to project a grindstone blade  72  which is a cutting blade. A recessed portion  711  is formed at a predetermined location of the base  71  of the thus constituted electroformed grindstone blade  7 , and the radio IC tag  3  is embedded in this recessed portion  711  and molded with a synthetic resin or the like. Data on the characteristic properties such as the thickness and edge projecting length of the grindstone blade  72  and the size and density of the abrasive grains are stored in the radio IC tag  3 , and the above use record can be recorded in the radio IC tag  3 . Since the rotation balance of the electroformed grindstone blade  7  is slightly changed by embedding the radio IC tag  3  in the disk-like base  71 , it is desired that a balancing member  712  should be arranged at a position deviated by 180° from the position where the radio IC tag  3  is embedded of the base  71 .