Patent Publication Number: US-10759088-B2

Title: Cutting blade mounting method

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a method of mounting a cutting blade in a cutting apparatus. 
     Description of the Related Art 
     In manufacture of semiconductor devices or the like, a plurality of sections are set by planned dividing lines formed in a lattice manner on a top surface of a wafer, a device such as an large scale integrated circuit (LSI) or an integrated circuit (IC) is formed in each section, and the wafer is divided into individual devices by performing cutting processing along the planned dividing lines by a cutting apparatus provided with a cutting blade. The cutting apparatus includes at least a chuck table holding the wafer and a cutting unit having a spindle that rotatably supports the cutting blade. The cutting blade is rotated via the spindle, and the wafer held on the chuck table is cut by the cutting blade. 
     When the axis of the spindle in the cutting unit and the rotational center of the cutting blade mounted on the spindle are even slightly eccentric to each other, the cutting blade vibrates in a direction orthogonal to the axis of the spindle, that is, a cutting direction, during high-speed rotation of the spindle mounted with the cutting blade. When the wafer is cut along the planned dividing lines in a state in which the cutting blade is vibrating, relatively large chips (chipping) occur on both sides of a cut groove, thus degrading device quality. 
     Particularly in a case where the cutting blade is a washer blade (hubless blade) formed by only an annular cutting edge, when the cutting blade is attached to a mount mounted on an end of the spindle, the cutting blade is mounted in a state in which the center of the cutting blade is slightly eccentric to the axis of the spindle due to the own weight of the cutting blade. Therefore, when replacement with the new cutting blade is performed, perfect circle setting dressing (perfect circle dressing) is performed which corrects the outer circumference of the cutting blade (see Japanese Patent Laid-Open No. 2006-218571, for example). 
     SUMMARY OF THE INVENTION 
     However, when the above-described perfect circle dressing is performed, the edge of the cutting blade is crushed. Thus, setting dressing for correcting the crushed edge needs to be performed next. Therefore, much time is needed for preparation (perfect circle dressing and setting dressing or the like) for making product cutting processing possible after the cutting blade is newly mounted. 
     It is accordingly an object of the present invention to provide a cutting blade mounting method that can mount a new cutting blade in a state in which a perfect circle is set. 
     In accordance with an aspect of the present invention, there is provided a cutting blade mounting method of sandwiching both side surfaces of a cutting blade formed by an annular cutting edge by sandwiching surfaces of a first flange and a second flange, and mounting the cutting blade onto a spindle, the first flange being mounted on an end of the spindle and having a suction hole sucking and holding a side surface of the cutting blade to the sandwiching surface, the cutting blade mounting method including: a cutting blade provisional holding step of sucking and holding the cutting blade to the first flange by making the cutting blade abut against the sandwiching surface of the first flange at a perfect circle position at which a center of the cutting blade coincides with an axis of the spindle, and making a suction force act on the suction hole; and a fixing step of fixing the cutting blade maintaining the perfect circle position to the first flange by the second flange after the cutting blade provisional holding step is performed. 
     According to the cutting blade mounting method in accordance with the present invention, the center of the cutting blade is set at the perfect circle position coinciding with the axis of the spindle in the cutting blade provisional holding step, and the fixing step is performed while the perfect circle position is maintained by suction. Consequently, eccentricity or the like of the cutting blade due to the own weight of the cutting blade does not occur, and the cutting blade is surely retained at the perfect circle position at a time of completion of the mounting. 
     According to the cutting blade mounting method in accordance with the present invention, a new cutting blade can be mounted in a state in which a perfect circle is set, and therefore an improvement in processing efficiency can be realized by shortening a time taken before cutting processing becomes possible. 
     The above and other objects, features and advantages of the present invention and the manner of realizing them will become more apparent, and the invention itself will best be understood from a study of the following description and appended claim with reference to the attached drawings showing a preferred embodiment of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of a cutting unit; 
         FIG. 2  is a perspective view of the cutting unit; 
         FIG. 3  is a sectional view depicting a state in which a cutting blade is held by a blade holding jig and a blade loading jig; 
         FIG. 4  is a sectional view depicting a cutting blade provisional holding step; 
         FIG. 5  is a sectional view depicting the cutting blade provisional holding step; and 
         FIG. 6  is a sectional view depicting a state in which a fixing step of fixing the cutting blade is completed. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A mounting method and a mounting structure for a cutting blade according to a present embodiment will hereinafter be described with reference to the accompanying drawings.  FIG. 1  depicts a state in which a cutting unit having a cutting blade is disassembled.  FIG. 2  depicts the cutting unit in a completed state in which the cutting blade is mounted.  FIGS. 3 to 6  depict steps for mounting the cutting blade. 
     The cutting unit  10  depicted in  FIG. 1  and  FIG. 2  constitutes a cutting apparatus. Though a general configuration of the cutting apparatus is not depicted, the cutting unit  10  is supported so as to be movable in a processing feed direction (X-axis direction), an indexing feed direction (Y-axis direction), and a raising or lowering direction (Z-axis direction) relative to a chuck table that holds workpiece (wafer) as a cutting object. 
     As depicted in  FIG. 1 , the cutting unit  10  has a spindle  12  supported so as to be rotatable, with respect to a spindle housing  11 , about an axis P (represented by alternate long and short dashed lines in each figure except  FIG. 3 ) of the spindle facing in the Y-axis direction. The spindle  12  has a tapered shape in which the diameter of an end part thereof is gradually decreased. A screw hole  13  is formed in an end surface of the spindle  12 . As depicted in  FIG. 6 , the cutting blade  14  is sandwiched by a blade mounter  20  and a fixing flange  40 , and mounted on an end portion of the spindle  12 . When the spindle  12  is rotation-driven, the cutting blade  14  rotates, and performs cutting processing on the workpiece. A structure and a method for mounting the cutting blade  14  on the spindle  12  will be described in detail in the following. Incidentally, as for the blade mounter  20  and the fixing flange  40 , a surface facing an opposite side from the spindle housing  11  in the Y-axis direction (surface facing in the same direction as the end surface of the spindle  12 ) will be set as a front surface, and a surface on a side facing the spindle housing  11  (surface facing a base end side of the spindle  12 ) will be set as a back surface. 
     The cutting blade  14  is a washer blade (hubless blade) formed by only an annular cutting edge. The cutting blade  14  is formed by solidifying diamond abrasive grains with a bonding agent. A circular opening  14   a  is formed on the inside of the cutting blade  14 . An inner circumferential portion of the circular opening  14   a  is concentric with an outer circumferential portion of the cutting blade  14 . 
     As depicted in  FIG. 1  and  FIG. 6 , the blade mounter  20  includes a cylindrical portion  21  located on the back side and a flange  22  (first flange) projecting radially outward from the cylindrical portion  21 . A sandwiching surface  23 , a flange portion  24 , and a boss portion  25  are formed on the front surface side of the flange  22 . The sandwiching surface  23  is an annular surface located on an outer circumference side of the flange  22  and orthogonal to the Y-axis direction. The flange portion  24  is a circular projecting portion located on an inner circumference side of the sandwiching surface  23  and projecting to the front surface side. The diameter of the flange portion  24  is set slightly smaller than the inside diameter of the circular opening  14   a  of the cutting blade  14 . In the vicinity of a front end of the boss portion  25 , an external thread  28  is formed on an outer circumferential surface of the boss portion  25 , and an internal thread  29  is formed on an inner circumferential surface of the boss portion  25  (see  FIG. 1  and  FIG. 6 ). 
     As depicted in  FIG. 6 , a fitting hole  26  and a circular recessed portion  27  communicating with each other in the Y-axis direction are formed in a center in a radial direction of the blade mounter  20 . The fitting hole  26  is located on the back side, and opens to an end surface of the cylindrical portion  21 . The circular recessed portion  27  is located on the front surface side, and opens to an end surface of the boss portion  25 . The inside diameter of the circular recessed portion  27  is larger than the inside diameter of the fitting hole  26 . A bottom surface  27   a  is formed within the circular recessed portion  27 . An inner circumferential surface of the fitting hole  26  has a tapered shape in which the inside diameter of the inner circumferential surface of the fitting hole  26  is reduced toward the front surface side. The end part of the spindle  12  is inserted into the fitting hole  26  in a press-fitting state. Then, a washer  15  is inserted into the circular recessed portion  27  and made to abut against the bottom surface  27   a , and a fixing bolt  16  is screwed into the screw hole  13  formed in the end surface of the spindle  12  and fastened. The blade mounter  20  is thereby fixed to the spindle  12  (see  FIG. 6 ). In a state in which the blade mounter  20  is fixed, the center of the annular sandwiching surface  23  coincides with the axis P of the spindle. 
     As depicted in  FIG. 6 , the cutting blade  14  is mounted on the blade mounter  20  in a state in which the flange portion  24  is inserted in the circular opening  14   a  and one side surface of the cutting blade  14  abuts against the sandwiching surface  23 . The mounting of the cutting blade  14  will be described later. 
     As depicted in  FIG. 1 , a plurality of suction holes  30  are formed at different positions in a rotational direction (circumferential direction) on the sandwiching surface  23  of the blade mounter  20 . As depicted in  FIG. 6 , a plurality of suction passages  31  communicating with the respective suction holes  30  are formed within the blade mounter  20 . Each of the suction passages  31  opens to a bottom surface of an annular groove  32  formed on an outer circumferential surface of the cylindrical portion  21 . The annular groove  32  is a groove extending in a circumferential direction of the cylindrical portion  21 , and is continuously formed over the whole circumference of the cylindrical portion  21 . 
     The fixing flange  40  (second flange) has a fitting hole  41  having an inside diameter corresponding to the diameter of the boss portion  25  of the blade mounter  20 . The fixing flange  40  is supported by the blade mounter  20  by inserting the boss portion  25  into the fitting hole  41 . As depicted in  FIG. 6 , the back side of the fixing flange  40  is provided with an annular sandwiching surface  42  in a position opposed to the sandwiching surface  23  of the blade mounter  20 . The boss portion  25  and the fitting hole  41  have shapes capable of relative movement in the Y-axis direction. The fixing flange  40  is inserted to a position at which the sandwiching surface  42  abuts against a side surface of the cutting blade  14  (side surface opposite from the side abutting against the sandwiching surface  23 ). In this state, the external thread  28  at the front end of the boss portion  25  projects to the front surface side of the fixing flange  40 , and the fixing flange  40  is fixed to the blade mounter  20  by screwing and fastening an annular fixing nut  45  onto the external thread  28 . 
     The cutting blade  14  is thus sandwiched between the sandwiching surface  23  of the blade mounter  20  and the sandwiching surface  42  of the fixing flange  40 . The outside diameter of the cutting blade  14  is larger than the respective outside diameters of the flange  22  of the blade mounter  20  and the fixing flange  40 , so that the outer circumferential portion of the cutting blade  14  projects radially outward of the blade mounter  20  and the fixing flange  40  (see  FIG. 2  and  FIG. 6 ). 
     A rotary joint  50  is mounted on an end portion of the spindle housing  11 . The rotary joint  50  includes a cylindrical supporting tube  51  and an attachment plate  52  projecting radially outward from the supporting tube  51 . Attachment screws  53  (see  FIG. 1  and  FIG. 2 ) inserted through a plurality of screw insertion holes (not depicted) formed in the attachment plate  52  are screwed and fastened into screw holes  17  (see  FIG. 1 ) formed in the end portion of the spindle housing  11 . The rotary joint  50  is thereby fixed to the spindle housing  11 . The supporting tube  51  is provided with a cylindrical portion  55  projecting radially outward. A communicating passage  56  is formed within the cylindrical portion  55 . One end of the communicating passage  56  opens to an inner circumferential surface of the supporting tube  51 . Another end of the communicating passage  56  opens to an end of the cylindrical portion  55 . 
     The rotary joint  50  is attached to the spindle housing  11  before the blade mounter  20  is mounted onto the spindle  12 . When the blade mounter  20  is mounted onto the spindle  12 , the cylindrical portion  21  is rotatably inserted into the inside of the supporting tube  51 . As depicted in  FIG. 6 , in a state in which the cylindrical portion  21  is inserted in the supporting tube  51 , the annular groove  32  communicates with the communicating passage  56 . Because the annular groove  32  is formed over the whole circumference of the cylindrical portion  21 , the annular groove  32  and the communicating passage  56  maintain the communicating state at all times even when the blade mounter  20  is at any position in a rotational direction with respect to the rotary joint  50 . That is, in a state in which the blade mounter  20  is mounted on the spindle  12 , a suction passage is formed which continues from the suction holes  30  through the suction passages  31  and the annular groove  32  to the communicating passage  56 . As depicted in  FIGS. 4 to 6 , a suction pipe passage extending from a suction source  90  is connected to the cylindrical portion  55 . When the suction source  90  is driven, an air can be sucked from the suction holes  30  through the above-described suction passage. Incidentally, the inner circumferential surface of the supporting tube  51  covers parts of the annular groove  32  other than a part thereof opposed to the communicating passage  56 . Thus, no air leakage occurs in the middle of the suction passage, so that suction efficiency is not impaired. 
     A mounting jig used for mounting the cutting blade  14  onto the blade mounter  20  will next be described. The mounting jig includes a blade holding jig  60 , a blade loading jig  70 , and a mounting guiding jig  80 . 
     As depicted in  FIGS. 3 to 5 , the blade holding jig  60  has a main body portion  61  of a cylindrical shape, and one end surface of the main body portion  61  is a suction surface  61   a , which is an annular flat surface that can abut against a side surface of the cutting blade  14 . A large-diameter recessed portion  62  and a small-diameter recessed portion  63  are formed within the main body portion  61 . The large-diameter recessed portion  62  is a recessed portion having a cylindrical inner circumferential surface, and opens to an inside in a radial direction of the suction surface  61   a . The small-diameter recessed portion  63  is recessed from a bottom surface  62   a  of the large-diameter recessed portion  62 , and is a recessed portion having a cylindrical inner circumferential surface of a smaller diameter than the large-diameter recessed portion  62 . The small-diameter recessed portion  63  has a bottom surface  63   a  parallel with the suction surface  61   a . The inner circumferential surface of the large-diameter recessed portion  62  and the inner circumferential surface of the small-diameter recessed portion  63  are arranged concentrically. The suction surface  61   a  is an annular surface concentric with the large-diameter recessed portion  62  and the small-diameter recessed portion  63 . 
     A suction hole  64  is formed on the suction surface  61   a . The suction hole  64  is an annular hole concentric with the suction surface  61   a . A connecting portion  65  to which a suction pipe passage extending from a suction source  91  is connected is provided on a side surface of the main body portion  61 . A suction passage  66  that makes the suction hole  64  and the connecting portion  65  communicate with each other is formed within the main body portion  61 . The suction passage  66  includes an annular part connected to the suction hole  64  and surrounding the large-diameter recessed portion  62  and the small-diameter recessed portion  63  and a part connected to the connecting portion  65  and extending in the radial direction of the main body portion  61 . 
     An annular auxiliary portion  67  is mounted on the outside of the main body portion  61  of the blade holding jig  60 . The annular auxiliary portion  67  is an annular body surrounding an outer circumferential surface of the main body portion  61 . The annular auxiliary portion  67  has an annular surface  67   a  that becomes flush with the suction surface  61   a  in a state in which the annular auxiliary portion  67  is mounted on the main body portion  61 . A plurality of kinds of annular auxiliary portions  67  whose annular surface  67   a  has different diameters are prepared. An annular auxiliary portion  67  of an appropriate size is selected according to a difference in the diameter of the cutting blade  14  to be mounted onto the blade mounter  20 , and is mounted onto the main body portion  61 . Specifically, a setting is made such that the suction surface  61   a  and the annular surface  67   a  can support the whole side surface on one side of the cutting blade  14  (see  FIG. 4 ). 
     As depicted in  FIG. 3 , the blade loading jig  70  includes a disk-shaped base portion  71  as well as a regulating portion  72  and a guiding projecting portion  73  that project from the base portion  71 . The base portion  71  has a blade supporting surface  71   a , which is an annular flat surface on which a side surface of the cutting blade  14  can be mounted. The regulating portion  72  projects from the blade supporting surface  71   a . Formed on an external surface of the regulating portion  72  are a regulating surface  72   a  as a cylindrical surface having a diameter corresponding to the inside diameter of the circular opening  14   a  of the cutting blade  14 , a tapered surface  72   b  as a side surface of a circular truncated cone which surface is continuous with the regulating surface  72   a , and an insertion regulating surface  72   c  as an upper surface of the circular truncated cone. The insertion regulating surface  72   c  is a plane parallel with the blade supporting surface  71   a . The guiding projecting portion  73  is a cylindrical projection projecting from the insertion regulating surface  72   c . Formed on an external surface of the guiding projecting portion  73  are an insertion guiding surface  73   a  as a cylindrical surface concentric with the regulating surface  72   a  and a tapered surface  73   b  as a side surface of a circular truncated cone which surface is continuous with the insertion guiding surface  73   a.    
     As depicted in  FIG. 3 , the regulating portion  72  and the guiding projecting portion  73  of the blade loading jig  70  can be inserted into the large-diameter recessed portion  62  and the small-diameter recessed portion  63  of the blade holding jig  60 . The regulating surface  72   a  of the regulating portion  72  has a diameter corresponding to the inside diameter of the large-diameter recessed portion  62 . The insertion guiding surface  73   a  of the guiding projecting portion  73  is of a smaller diameter than the regulating surface  72   a , and has a diameter corresponding to the inside diameter of the small-diameter recessed portion  63 . Insertion of the blade loading jig  70  into the blade holding jig  60  is restricted at a position at which the insertion regulating surface  72   c  abuts against the bottom surface  62   a  (see  FIG. 3 ). In this insertion restricted state, the suction surface  61   a  and the annular surface  67   a  on the blade holding jig  60  side are opposed to the blade supporting surface  71   a  on the blade loading jig  70  side with a predetermined gap (slightly larger than the thickness of the cutting blade  14 ) therebetween. In addition, the regulating surface  72   a  is located on a side of a part where the suction surface  61   a  and the blade supporting surface  71   a  are opposed to each other. 
     As depicted in  FIG. 4  and  FIG. 5 , the mounting guiding jig  80  has a cylindrical shape similar to that of the guiding projecting portion  73  of the blade loading jig  70 . Formed on an external surface of the mounting guiding jig  80  are an insertion guiding surface  80   a  as a cylindrical surface, a tapered surface  80   b  as a side surface of a circular truncated cone which surface is continuous with the insertion guiding surface  80   a , and an insertion regulating surface  80   c  as an upper surface of the circular truncated cone. The mounting guiding jig  80  can be inserted into the small-diameter recessed portion  63  of the blade holding jig  60 . The insertion guiding surface  80   a  has a diameter corresponding to the inside diameter of the small-diameter recessed portion  63 . An external thread  81  is formed on a base end of the mounting guiding jig  80 . The external thread  81  can be screwed into the internal thread  29  formed in the boss portion  25  of the blade mounter  20 . 
     The blade holding jig  60 , the blade loading jig  70 , and the mounting guiding jig  80  are each a rigid body formed of stainless steel or the like. The blade holding jig  60 , the blade loading jig  70 , and the mounting guiding jig  80  each have a high shape precision, and can be combined with each other with high precision without occurrence of a backlash or the like. Therefore, in a state in which the blade holding jig  60  and the blade loading jig  70  are combined with each other as in  FIG. 3 , or in a state in which the blade holding jig  60  and the mounting guiding jig  80  are combined with each other as in  FIG. 4  and  FIG. 5 , the jigs can be coupled to each other and slid with respect to each other with high precision. Specifically, the blade holding jig  60  and the blade loading jig  70  are capable of relative movement in a direction along a central axis of the guiding projecting portion  73 , and the blade holding jig  60  and the mounting guiding jig  80  are capable of relative movement in a direction along a central axis of the mounting guiding jig  80 . 
     Incidentally, in the present embodiment, an inner surface of the small-diameter recessed portion  63  of the blade holding jig  60  is a cylindrical surface, and the external surface of the guiding projecting portion  73  of the blade loading jig  70  and the external surface of the mounting guiding jig  80  to be inserted into the small-diameter recessed portion  63  are respectively the insertion guiding surface  73   a  and the insertion guiding surface  80   a  having a cylindrical shape. However, shapes other than the cylindrical surfaces (shapes such as an angular hole and a prism as an example) can also be selected as long as the shapes can guide the jigs so as to be capable of relative movement as described above. 
     Description will be made of work of mounting the cutting blade  14  using the mounting jig described above. In a stage before the cutting blade  14  is mounted, the blade mounter  20  side is in a state depicted in  FIG. 4 . That is, the blade mounter  20  is mounted on the spindle  12 , and the rotary joint  50  is attached to the spindle housing  11 , so that a suction force from the suction source  90  acts on the suction holes  30  through the communicating passage  56 , the annular groove  32 , and the suction passages  31 . The fixing flange  40  has been removed from the blade mounter  20 . In addition, the mounting guiding jig  80  is mounted onto the blade mounter  20  by screwing the external thread  81  into the internal thread  29  before attachment of the cutting blade  14  to the blade mounter  20  which attachment will be described later. 
     First, the cutting blade  14  is attached to the blade loading jig  70 . More specifically, the circular opening  14   a  of the cutting blade  14  is inserted from the guiding projecting portion  73  side. The inner circumferential portion of the circular opening  14   a  is inserted while guided by the tapered surface  72   b . The insertion is regulated when the circular opening  14   a  moves to a position where a side surface of the cutting blade  14  abuts against the blade supporting surface  71   a  (position depicted in  FIG. 3 ). In this state, the position of the inner circumferential portion of the circular opening  14   a  is regulated by the regulating surface  72   a . The position regulated by the regulating surface  72   a  corresponds to a perfect circle position at which the center of the cutting blade  14  coincides with the axis P of the spindle when the cutting blade  14  is finally mounted on the blade mounter  20 . 
     Next, as depicted in  FIG. 3 , the blade holding jig  60  is mounted onto the blade loading jig  70  in a state of supporting the cutting blade  14 . When the blade holding jig  60  is mounted onto the blade loading jig  70 , the guiding projecting portion  73  is inserted into the small-diameter recessed portion  63 . The insertion can be performed smoothly due to the tapered surface  73   b  formed on the guiding projecting portion  73 . When the insertion proceeds, the regulating portion  72  advances into the large-diameter recessed portion  62 . The insertion is regulated when the insertion regulating surface  72   c  abuts against the bottom surface  62   a . In this stage, there is a minute gap between a side surface of the cutting blade  14  supported on the blade supporting surface  71   a  (side surface opposite from the side supported by the blade supporting surface  71   a ) and the suction surface  61   a  and the annular surface  67   a . There is thus no fear of damaging the cutting blade  14  due to a load. 
     When combination of the blade holding jig  60  and the blade loading jig  70  with each other is completed as in  FIG. 3 , the suction source  91  is driven to make a suction force act on the suction hole  64 . The suction causes the side surface of the cutting blade  14  (side surface opposite from the side supported by the blade supporting surface  71   a ) to be sucked and held by the suction surface  61   a  and the annular surface  67   a . In stages before the cutting blade  14  is sucked and held on the blade holding jig  60  side (a step of mounting the cutting blade  14  onto the blade loading jig  70  and a step of mounting the blade holding jig  60  onto the blade loading jig  70 ), it is preferable to direct the base portion  71  downward, and insert the cutting blade  14  and the blade holding jig  60  onto the blade loading jig  70  in a vertical direction, as depicted in  FIG. 3 . It is thereby possible to prevent positional displacement and falling off of the cutting blade  14 . 
     When the cutting blade  14  is sucked and held by the suction surface  61   a  and the annular surface  67   a , the blade loading jig  70  is removed from the blade holding jig  60 . The cutting blade  14  is sucked and held on the blade holding jig  60  side while continuing maintaining a radial direction position (perfect circle position) regulated by the regulating surface  72   a  in the above-described stage of mounting the cutting blade  14  onto the blade loading jig  70 . In other words, a state is maintained in which the center of the annular cutting blade  14  coincides with the central axis of the large-diameter recessed portion  62  and the small-diameter recessed portion  63  of the blade holding jig  60 . 
     Next, as depicted in  FIG. 4 , the small-diameter recessed portion  63  of the blade holding jig  60  in the state of sucking and holding the cutting blade  14  is inserted onto the mounting guiding jig  80  mounted on the blade mounter  20 . The insertion can be performed smoothly due to the tapered surface  80   b  formed on the mounting guiding jig  80 . Incidentally, although the blade holding jig  60  is mounted onto the mounting guiding jig  80  in a state of being laid sideways with respect to the Z-axis direction as the vertical direction (see  FIG. 4 ), positional displacement and falling off of the cutting blade  14  do not occur because the cutting blade  14  is held by the suction force acting on the suction hole  64 . 
     When the blade holding jig  60  is inserted onto the mounting guiding jig  80 , a side surface of the cutting blade  14  (side surface opposite from the side sucked by the suction surface  61   a ) approaches the sandwiching surface  23  of the blade mounter  20 . At this time, the cutting blade  14  maintains the above-described radial direction position (perfect circle position) set by the regulating surface  72   a  of the blade loading jig  70 . The cutting blade  14  can therefore approach the sandwiching surface  23  in a positional relation such that the flange portion  24  of the blade mounter  20  fits into the inside of the circular opening  14   a  without the cutting blade  14  interfering with the flange portion  24 . 
     The blade holding jig  60  is inserted until the cutting blade  14  abuts against the sandwiching surface  23  of the blade mounter  20 . Incidentally, to prevent the blade mounter  20  and the blade holding jig  60  from applying an excessive sandwiching force to the cutting blade  14  at this time, movement in the insertion direction of the blade holding jig  60  may be regulated by abutment between the insertion regulating surface  80   c  of the mounting guiding jig  80  and the bottom surface  63   a  of the small-diameter recessed portion  63 . In this case, a setting is made such that a distance between the suction surface  61   a  and the annular surface  67   a  and the sandwiching surface  23  coincides with the thickness of the cutting blade  14  in a stage in which the insertion regulating surface  80   c  and the bottom surface  63   a  abut against each other. 
     Next, when the suction source  90  is driven to make a suction force act on the suction holes  30 , a force for sucking the side surface of the cutting blade  14  acts on the sandwiching surface  23  of the blade mounter  20 . Then, when the suction force on the blade holding jig  60  side (suction and holding to the suction surface  61   a  and the annular surface  67   a ) is released by stopping driving the suction source  91 , the cutting blade  14  is sucked and held by the sandwiching surface  23 . That is, switching is performed from a state in which the cutting blade  14  is held on the blade holding jig  60  side to a state in which the cutting blade  14  is held on the blade mounter  20  side. 
     The blade holding jig  60  is pulled out from the mounting guiding jig  80  as depicted in  FIG. 5  while the state in which the cutting blade  14  is sucked and held by the sandwiching surface  23  is maintained. When the blade holding jig  60  is pulled out, the driving of the suction source  90  is continued, and the suction force acting on the sandwiching surface  23  continues to hold the cutting blade  14  on the blade mounter  20  side. The cutting blade  14  at this time continues to maintain the radial direction position (perfect circle position) regulated by the regulating surface  72   a  in the above-described stage of mounting the cutting blade  14  onto the blade loading jig  70 , and the center of the cutting blade  14  coincides with the spindle axis P of the spindle  12 . 
     The above stages constitute a cutting blade provisional holding step of provisionally holding the cutting blade  14  on the blade mounter  20 . As described above, in the cutting blade provisional holding step, the holding of the cutting blade  14  is handed over from the blade loading jig  70  to the blade holding jig  60  and then to the blade mounter  20  in this order. However, in each of the stages, the central position of the cutting blade  14  which central position is first regulated by the regulating surface  72   a  of the blade loading jig  70  is maintained without being displaced, and the cutting blade  14  can be provisionally held in a state in which the center of the cutting blade  14  coincides with the spindle axis P of the spindle  12 . That is, perfect circle setting of the cutting blade  14  is completed in the provisional holding stage. 
     Finally, as depicted in  FIG. 6 , the fixing flange  40  is mounted by inserting the fitting hole  41  onto the boss portion  25  of the blade mounter  20 , and a fixing step is performed which fixes the fixing flange  40  by screwing the fixing nut  45  onto the external thread  28 . When the fixing step is performed, a fixed state is obtained in which both side surfaces of the cutting blade  14  are sandwiched by the sandwiching surface  23  and the sandwiching surface  42 , and movement of the cutting blade  14  in each of the X-axis, Y-axis, and Z-axis directions with respect to the spindle  12  is restricted. The driving of the suction source  90  is stopped after the fixing of the fixing flange  40 . The cutting blade  14  is already fixed by sandwiching. Thus, even when the suction force from the suction holes  30  is released, positional displacement and falling off of the cutting blade  14  do not occur. 
     As described above, according to the cutting blade mounting method in accordance with the present embodiment, the blade mounter  20  holds the cutting blade  14  at the perfect circle position at which the center of the cutting blade  14  coincides with the spindle axis P of the spindle  12  in the cutting blade provisional holding step, and the fixing step of fixing the fixing flange  40  is performed while the perfect circle position of the cutting blade  14  is maintained by suction. Eccentricity or the like of the cutting blade  14  due to the own weight of the cutting blade  14  does not occur during mounting, and a proper perfect circle position is achieved in a state in which the mounting of the new cutting blade  14  is completed. Hence, processing can be performed immediately by saving a time taken for perfect circle dressing and setting dressing after mounting the cutting blade  14 , so that processing efficiency of the cutting apparatus can be improved. Incidentally, the mounting of the cutting blade to which the present invention is applied may be performed by an auto blade changer that automatically replaces the cutting blade, or may be performed by blade replacement by manual operation of an operator. 
     The blade mounter  20  and the fixing flange  40  used to hold the cutting blade  14  and the mounting jig (the blade holding jig  60 , the blade loading jig  70 , and the mounting guiding jig  80 ) used at the time of mounting the cutting blade  14  can adopt configurations different from those of the present embodiment. 
     For example, the configuration of the suction structure provided to the blade mounter  20  may be changed as long as the suction structure can surely suck and hold the cutting blade  14  in the cutting blade provisional holding step. Specifically, while the plurality of suction holes  30  are provided at predetermined intervals on the sandwiching surface  23  of the blade mounter  20  in the present embodiment, a continuous annular suction hole (hole in a form such as that of the suction hole  64  of the blade holding jig  60 ) may be provided in place of the plurality of suction holes  30 . 
     As target workpiece to be cut by the cutting blade mounted by applying the present invention, various kinds of workpiece may be used, such as a semiconductor device wafer, an optical device wafer, a package substrate, a semiconductor substrate, an inorganic material substrate, an oxide wafer, a raw ceramic substrate, a piezoelectric substrate, and the like. A silicon wafer or a compound semiconductor wafer after the formation of devices may be used as the semiconductor device wafer. A sapphire wafer or a silicon carbide wafer after the formation of devices may be used as the optical device wafer. In addition, a chip size package (CSP) substrate may be used as the package substrate, silicon, gallium arsenide, or the like may be used as the semiconductor substrate, and sapphire, ceramics, glass, or the like may be used as the inorganic material substrate. Further, lithium tantalate or lithium niobate after the formation of devices or before the formation of devices may be used as the oxide wafer. 
     In addition, the embodiment of the present invention is not limited to the foregoing embodiment and modifications, but may be changed, replaced, and modified in various manners without departing from the spirit of technical ideas of the present invention. Further, when a technical idea of the present invention can be realized in a different manner by progress of a technology or another derived technology, the technical idea of the present invention may be carried out by using the method. Hence, the claim covers all embodiments that can be included within the scope of the technical ideas of the present invention. 
     As described above, according to the cutting blade mounting method in accordance with the present invention, perfect roundness of the cutting blade with respect to the spindle at a point in time of completion of mounting of the new cutting blade is ensured. Thus, productivity can be improved by shortening a time taken before the cutting blade is mounted and becomes able to perform processing. 
     The present invention is not limited to the details of the above described preferred embodiment. The scope of the invention is defined by the appended claim and all changes and modifications as fall within the equivalence of the scope of the claim are therefore to be embraced by the invention.