JP2011054847A - Cutting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily detect a narrow gap caused by attaching cutting waste around the gap constituting an air curtain without such a complicated operation as dismounting a cutting blade, in an air-spindle unit where the cutting blade is mounted. <P>SOLUTION: An air curtain 75 is formed by ejecting air for an air bearing from a gap 74 formed in between a cap 83 at the extremity of a housing 80 in an air-spindle unit 70 and a blade mount 66 mounted at the extremity of a rotating shaft 90 in the housing 80, for the purpose of preventing a cutting liquid from entering into the gap 74. An air-compressing chamber 833 is formed inside the cap 83 to pass through the air just before the air curtain 75 is formed, and the pressure in the air-compressing chamber 833 is detected by a pressure sensor 85. When the pressure rises, it is determined that the gap 74 is narrowed by the attached cutting waste. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cutting apparatus that cuts or grooves a thin plate workpiece such as a semiconductor wafer or a substrate of various electronic components with a cutting blade, and in particular, an air spindle that supports a rotating shaft of the cutting blade with air. The present invention relates to a cutting apparatus including a unit.

  As a device that divides a workpiece as described above into a large number of chips, a cutting device that cuts a disk-shaped cutting blade rotated at a high speed into the workpiece is widely used. Some cutting apparatuses of this type support a cutting blade by an air spindle unit. The air spindle unit is configured to rotatably insert a rotating shaft on which a cutting blade is mounted into a housing and supply high-pressure air into the housing. The rotating shaft is configured by a radial air bearing and a thrust air bearing of the housing. It is supported so as to be rotatable in a state where a certain distance is maintained between the housing and the housing (see Patent Document 1, etc.).

  In such a cutting apparatus, cutting is usually performed while supplying a cutting fluid near the processing point where the cutting blade contacts the workpiece. The cutting fluid is supplied mainly for the purpose of cooling because frictional heat generated by cutting causes wear or breakage of the cutting blade or chipping (chip) of the workpiece. The cutting fluid is also supplied for the purpose of washing away and removing the cutting waste from the processing point or lubricating the processing point.

  By the way, when the cutting fluid is supplied to the machining point, the cutting waste (contamination) generated by the cutting is scattered in a state mixed with the cutting fluid. Therefore, it occurs that cutting waste adheres to various parts of the cutting device. Here, in particular, when cutting waste enters a gap formed between the rotary shaft of the air spindle unit and the housing and adheres to the housing side and solidifies, for example, a so-called galling phenomenon occurs between the rotary shaft and the housing. May occur, causing problems in operation. Therefore, air forming the air bearing is ejected from the gap toward the outside of the housing to form an air curtain portion, and cutting fluid containing cutting waste is blocked by the air curtain portion to cut around the gap. It is practiced to prevent adhesion of debris.

JP 2000-21822 A

  However, if the cutting process is performed for a long time, cutting waste adheres and accumulates around the gap, and the gap becomes narrow and the air curtain part may not function normally. Also, in this situation, when it is attempted to visually check the state of the gap, a complicated work such as removing a cutting blade or a blade mount for attaching the cutting blade to the rotating shaft from the rotating shaft is required. Necessary.

  The present invention has been made in view of the above circumstances, and the main technical problem thereof is that cutting waste is formed around the gap forming the air curtain portion without performing a complicated operation such as removing a cutting blade or the like. An object of the present invention is to provide a cutting apparatus capable of easily detecting that the gap is narrowed due to adhesion of the metal.

The present invention includes an air spindle unit having a rotating shaft, a housing that supports the rotating shaft with air, and an air supply port for supplying air to a space formed between the rotating shaft and the housing. A blade mount attached to the tip of the rotating shaft;
A cutting apparatus comprising: a cutting blade mounted on the blade mount; and a holding table for holding a workpiece to be cut by the cutting blade, wherein the air supplied from the air supply port receives the rotary shaft and the housing An air curtain portion formed by being ejected from a gap formed between the housing and the blade mount attached to the tip of the rotating shaft, and the rotating shaft and the housing And an air pressure chamber that shows a change in pressure according to the air pressure in the air curtain portion, and an air pressure detection portion that detects the air pressure in the air pressure chamber.

  According to the present invention, the cutting fluid enters the gap between the housing and the blade mount, the cutting waste adheres to the housing or blade mount around the gap, and when the gap is narrowed, the pressure in the air pressure chamber is reduced. A change occurs, and this pressure change is detected by the air pressure detector. A threshold value is set for the pressure detected by the air pressure detection unit, and when the threshold value is exceeded, cutting chips adhere to at least one of the blade mount and the housing around the air curtain unit, so that there is a gap between the two. It can be detected that the gap has narrowed.

  The workpiece in the present invention is not particularly limited. For example, the semiconductor wafer such as a silicon wafer, an adhesive member such as DAF (Die Attach Film) provided on the back surface of the wafer for chip mounting, or a package of a semiconductor product. Further, various drivers such as ceramic or glass-based or silicon-based substrates, various electronic components, LCD drivers for controlling and driving liquid crystal display devices, and various processing materials that require micron-order accuracy are included. In addition, among these, cutting scrap generated at the time of cutting is easily solidified and accumulated in a cement form, and this is particularly effective when a ceramic is used as a workpiece, which tends to impair the cutting fluid intrusion preventing function of the air curtain part. is there.

  According to the present invention, it is possible to easily detect that the air curtain portion has become narrow due to attachment of cutting waste to the periphery of the air curtain portion without performing a complicated operation such as removing a cutting blade or the like. There are effects such as.

It is a perspective view which shows the semiconductor wafer which is the cutting device which concerns on one Embodiment of this invention, and a workpiece | work. It is a perspective view of the cutting means which the cutting device comprises. FIG. 3 is an overall sectional view of the cutting means shown in FIG. 2. It is sectional drawing to which the front-end | tip part to which the cutting blade of the air spindle unit which comprises a cutting means is attached was expanded. It is a perspective view which shows the attachment structure of the cutting blade with respect to the air spindle unit.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a cutting apparatus 10 according to an embodiment. The apparatus 10 uses a disk-shaped semiconductor wafer (hereinafter abbreviated as “wafer”) 1 shown in FIG. 1 as a workpiece, and automatically controls the cutting operation by the cutting blade 65 to handle the wafer 1 in a number of devices. It is a dicing apparatus for dicing into (semiconductor chip).

(1) Wafer First, the wafer 1 that is a workpiece will be described. The wafer 1 has a thickness of, for example, about 100 to 700 μm, and a large number of rectangular devices 2 are formed on the surface by grid-like division lines. These devices 2 are formed with electronic circuits such as IC and LSI (not shown). Cutting (dicing) by the cutting device 10 includes groove processing in which a groove is formed by cutting from the surface to the middle of the thickness in addition to a full cut that completely cuts through the thickness of the wafer 1. When the grooves are formed, the wafer 1 is divided into a number of devices 2 by further cutting the remaining thickness of the grooves with another cutting blade in the subsequent process or by applying stress to cleave them. The

  As shown in FIG. 1, the wafer 1 is supplied to the cutting apparatus 10 in a state where it is integrally supported by an inner side of an annular frame 3 via an adhesive tape 4. The adhesive tape 4 has an adhesive surface on one side, and the frame 3 and the wafer 1 are attached to the adhesive surface. The frame 3 has rigidity made of a plate material such as metal, and the wafer 1 is transferred by supporting the frame 3.

(2) Cutting Device (2-1) Configuration of Cutting Device Next, the configuration of the cutting device 10 shown in FIG. 1 will be described. The cutting device 10 is a biaxially opposed type in which a pair of the cutting blades 65 are arranged to face each other. A reference numeral 11 in FIG. 1 is a base, and a rectangular recess 12 whose long side extends in the X-axis direction is formed at the center of the base 11. A disc-shaped chuck table (holding table) 20 is provided in the recess 12 so as to be movable in the X-axis direction. Further, a portal column 30 straddling the recess 12 is fixed on the rear side (X2 direction side) on the base 11 in FIG.

  The chuck table 20 is supported on the table base 25 so as to be rotatable about the Z-axis direction which is the vertical direction as a rotation axis, and is rotated clockwise or counterclockwise by a rotation driving mechanism (not shown) provided on the table base 25. To be rotated. The table base 25 is reciprocated in the X-axis direction by a moving mechanism (not shown) disposed in the recess 12, so that the chuck table 20 reciprocates in the X-axis direction together with the table base 25.

  The chuck table 20 is of a general well-known vacuum chuck type, and most of the peripheral portion of the horizontal upper surface is a circular suction surface 21 that sucks and holds the wafer 1. The diameter of the suction surface 21 is substantially the same as the diameter of the wafer 1, and the entire wafer 1 is placed concentrically on the suction surface 21 and held. The wafer 1 supported by the frame 3 as described above is placed on the suction surface 21 of the chuck table 20 in a vacuum operation state, and is sucked and held. Around the chuck table 20, a plurality of clamps 26 for detachably holding the frame 3 are disposed. These clamps 26 are attached to the table base 25.

  The periphery of the chuck table 20 is covered with a rectangular plate cover 27. The plate cover 27 is supported by the table base 25 and moves in the X-axis direction together with the chuck table 20. An elastic bellows-like cover 28 that covers the recess 12 is attached to both ends of the plate cover 27 in the X-axis direction. The recess 12 is always covered with the plate cover 27 and the cover 28 even when the chuck table 20 moves in the X-axis direction. Thereby, the cutting fluid and cutting waste (contamination) used at the time of cutting are prevented from falling to the moving mechanism that moves the table base 25 in the X-axis direction.

  The portal column 30 has a pair of leg portions 31 erected side by side in the Y-axis direction on both sides of the recess 12, and a beam portion 32 laid horizontally between the upper ends of the leg portions 31. is doing. A pair of upper and lower Y-axis guides 33 extending in the Y-axis direction are provided on the front side (X1 direction side) of the beam portion 32 in FIG. 1, and the first Y-axis slider 41 and the Y-axis guide 33 are connected to the Y-axis guide 33. A second Y-axis slider 42 is slidably attached. The first Y-axis slider 41 is reciprocated along the Y-axis guide 33 by a first Y-axis ball screw feed mechanism 412 operated by a first Y-axis feed motor (not shown). The second Y-axis slider 42 is reciprocated along the Y-axis guide 33 by a second Y-axis ball screw feed mechanism 422 operated by a second Y-axis feed motor 421.

  The first Y-axis slider 41 and the second Y-axis slider 42 are each provided with a pair of Z-axis guides 34 extending in the Z-axis direction. The first Y-axis slider 41 includes a first Z-axis slider 51. The second Z-axis slider 52 is slidably attached to the Z-axis guide 34 of the second Y-axis slider 42. The first Z-axis slider 51 is moved up and down along the Z-axis guide 34 by a first Z-axis ball screw feed mechanism (not shown) operated by a first Z-axis feed motor 511. Further, the second Z-axis slider 52 is moved up and down along the Z-axis guide 34 by a second Z-axis ball screw feed mechanism (not shown) operated by the second Z-axis feed motor 512.

  The first cutting means 61 is fixed to the lower end of the first Z-axis slider 51 via a first bracket 611, and the second cutting is applied to the lower end of the second Z-axis slider 52 via a second bracket 621. Means 62 are fixed. The cutting means 61 and 62 have the same configuration, and the cutting blade 65 is attached to the tip of the air spindle unit 70.

  As shown in FIGS. 2 to 4 (FIG. 2 shows the cutting means 61), the air spindle unit 70 is inserted into the housing 80 having a cylindrical inner peripheral surface and is rotatably inserted into the housing 80. And a rotating shaft 90. The housing 80 includes a housing main body 81 having a bottom portion 811 on the rear end side (right side in FIGS. 3 and 4) into which most of the rotating shaft 90 is inserted, and an open front end side of the housing main body 81 (see FIGS. 3 and 4). The ring 82 is fixed to the left side in FIG. 4 and the cap 83 is fixed to the ring 82.

  As shown in FIG. 3, the housing body 81 is formed with an air supply path 812 that opens to the bottom 811 side and extends to the distal end side. The opening on the bottom 811 side of the air supply path 812 is an air supply port 813. It is said that. In addition, an air discharge port 814 is formed in the bottom 811 of the housing body 81. As shown in FIG. 4, the ring 82 is formed with an air discharge path 821 communicating with the air supply path 812 and the housing 80, and the air supplied from the air supply port 813 passes through the air supply path 812. The air is discharged from the air discharge path 821 into the housing 80 and supplied.

  The rotating shaft 90 is mainly composed of a body portion 91 inserted into the housing main body 81, and a flange portion 92 is formed at a portion corresponding to the ring 82 of the housing 80 at the front end portion of the body portion 91. . A groove 822 in which the flange 92 is fitted with a space is formed on the inner peripheral surface corresponding to the flange 92 of the ring 82 over the entire circumference. In the rotating shaft 90, an attachment shaft 93 for the cutting blade 65 is formed on the distal end side of the flange portion 92. The attachment shaft 93 and the flange 92 are formed concentrically with the body 91.

  As shown in FIG. 3, a motor 71 that rotates the rotating shaft 90 is provided at the rear end of the air spindle unit 70. The motor 71 includes a rotor 711 formed at the rear end of the body 91 of the rotating shaft 90 and a stator 712 disposed on the inner peripheral surface of the housing body 81 so as to face the rotor 711. . When the motor 71 is operated, the rotary shaft 90 is driven to rotate about the axis.

  When the rotary shaft 90 is rotationally driven, high-pressure air is introduced from the air supply port 813 into the air supply path 812, and air is supplied from the air discharge path 821 into the housing 80 as described above. The air supplied into the housing 80 is discharged from the air discharge port 814 to the outside of the housing 80. By supplying air into the housing 80 in this way, a radial air bearing 72 is formed between the peripheral surface of the rotating shaft 90 and the inner peripheral surface of the housing 80, and the side surface of the flange 92 and the ring A thrust air bearing 73 is formed between the thrust air bearing 73. By forming the air bearings 72 and 73, the rotating rotating shaft 90 is supported in a state where a certain distance is maintained between the rotating shaft 90 and the housing 80.

  The mounting shaft 93 of the rotating shaft 90 passes through the cap 83 of the housing 80 and protrudes toward the distal end side of the housing 80. As shown in FIGS. 4 and 5, the mounting shaft 93 is formed in a conical shape whose outer diameter decreases toward the tip, and a screw hole 931 is formed on the tip surface. The cutting blade 65 attached to the attachment shaft 93 is formed by attaching a blade portion 652 to the outer peripheral surface of one side (housing 80 side) of a ring-shaped base 651, and is attached to and detached from the attachment shaft 93 via the blade mount 66. Installed as possible. The blade mount 66 has a cylindrical portion 662 in which a tapered mounting hole 661 into which the mounting shaft 93 is fitted is formed at the shaft center, and a flange 663 formed on the outer peripheral surface in the axial direction of the cylindrical portion 662. Thus, a male screw portion 664 is formed in the cylindrical portion 662 on the tip side of the flange 663.

  In order to attach the cutting blade 65 to the attachment shaft 93, first, the attachment hole 661 of the blade mount 66 is fitted into the attachment shaft 93, and the bolt 68 passed through the washer 67 is screwed into the screw hole 931. The blade mount 66 is pushed toward the housing 80 by the washer 67, whereby the attachment shaft 93 is pressed into the attachment hole 661 and the blade mount 66 is fastened to the attachment shaft 93. Next, the hole 653 at the center of the base 651 in the cutting blade 65 is fitted into the male screw portion 664 of the blade mount 66, and the nut 69 is screwed into the male screw portion 664 and fastened. As a result, the cutting blade 65 is attached to the attachment shaft 93 via the blade mount 66.

  As shown in FIG. 4, the rear end portion (right end portion in FIG. 4) of the cylindrical portion 662 of the blade mount 66 faces the opening inner peripheral surface 831 of the cap 83 of the housing 80 with a slight gap 74 therebetween. ing. When the air spindle unit 70 is operated and the cutting blade 65 is rotating, the gap 74 is also held at a constant distance over the entire circumference. From this gap 74, the air supplied into the housing 80 from the air supply port 813 and passing through the space between the rotating shaft 90 and the housing 80 is jetted out of the housing 80. An air curtain portion 75 that prevents fluid from entering the gap 74 is formed by the air ejected from the gap 74 (indicated by an arrow extending leftward from the gap 74 in FIG. 4). Here, it is assumed that the air curtain portion 75 is formed by air passing through the gap 74 and air immediately after being ejected from the gap 74.

  As shown in FIG. 4, a groove 832 is formed over the entire inner peripheral surface of the cap 83 on the inner side of the opening inner peripheral surface 831, and the blade mount 66 is formed inside the cap 83 by the groove 832. An air pressure chamber 833 is formed in a state where the end face is closed. The air pressure chamber 833 communicates with the gap 74 that forms the air curtain portion 75, and a space that shows a pressure change according to the pressure of the air immediately before the air curtain portion 75 is ejected from the gap 74. It has become. The air pressure chamber 833 is provided with a pressure sensor (air pressure detector) 85 that detects the air pressure in the air pressure chamber 833. The pressure detected by the pressure sensor 85 is displayed so that the operator of the apparatus 10 can always recognize it.

  As shown in FIG. 1, the cutting means 61 and 62 having the above-described configuration are such that the air spindle unit 70 is parallel to the Y-axis direction and coaxial with each other, and the tips to which the cutting blades 65 are attached face each other. Is fixed to the lower end of each bracket 611, 621. The cutting means 61 and 62 are moved in the Y-axis direction integrally with the Y-axis sliders 41 and 42, respectively, and approach or separate from each other in the Y-axis direction.

  The cutting blade 65 cuts the wafer 1 held on the chuck table 20 by cutting the blade portion 652. In the present apparatus 10, since the rotary shaft 90 that supports the cutting blade 65 extends in the Y-axis direction, the machining feed direction in which the cutting blade 65 cuts into the wafer 1 and advances the cutting is the X-axis direction. On the other hand, the index feed direction for moving the cutting blade 65 in the axial direction is the Y-axis direction. Therefore, the machining feed of the cutting blade 65 is performed by moving the chuck table 20 in the X-axis direction and moving the wafer 1 in the X-axis direction relative to the cutting blade 65. Further, the indexing feed is performed by moving the cutting blade 65 in the Y-axis direction by the Y-axis sliders 41 and 42.

  As shown in FIG. 2, the cutting blade 65 is mainly covered with the blade cover 100 at the upper periphery, and the wafer 1 is cut by the lower edge blade portion 652 exposed from the blade cover 100. For example, the cutting blade 65 cuts into the wafer 1 and cuts it while rotating at high speed in the direction of arrow A in FIG. The blade cover 100 includes a base portion 101 that is fixed to the tip of the housing 80 of the air spindle unit 70. The base portion 101 includes a front cover 102 that covers the front in the rotational direction of the cutting blade 65, and a cutting. A movable cover 103 is provided to cover the upper side and the rear side of the blade 65. The movable cover 103 has a triangular side cover 103 a that covers the rear part of the exposed side surface of the cutting blade 65.

  A plurality of outer peripheral nozzles 111 (only one is visible in FIG. 2) arranged in the Y-axis direction are provided at the lower end portion of the surface of the front cover 102 facing the cutting blade 65. The liquid is ejected toward the cutting blade 65. In addition, two parallel side nozzles 112 whose front end portions extend in the X-axis direction are attached to the movable cover 103 so as to be disposed on both sides of the cutting blade 65. A plurality of slits 112 a are formed in these side nozzles 112, and a cutting fluid is ejected from the slits 112 a toward the cutting blade 65. Connection pipes 121 and 122 to which cutting fluid supply pipes are connected are respectively attached to the front cover 102 and the movable cover 103.

  The movable cover 103 is moved in the X2 direction by an air cylinder 104 fixed to the upper part of the base portion 101. The movable cover 103 is moved in the X2 direction and does not interfere with the side nozzle 112, and the cutting blade 65 and The blade mount 66 can be attached to and detached from the mounting shaft 93. On the upper surface of the air cylinder 104, a pair of connection pipes 131 are connected to which air piping for supplying / exhausting air to / from the air cylinder 104 is connected.

(2-2) Outline of Operation of Cutting Apparatus The above is the overall configuration of the cutting apparatus 10 according to an embodiment. Next, the operation of dicing the wafer 1 into a large number of devices 2 by the cutting apparatus 10 will be described.

  The wafer 1 is sucked and held on the chuck table 20 while being supported by the frame 3 via the adhesive tape 4 as described above, and the chuck table 20 moves in the X2 direction in FIG. It is conveyed to a machining position corresponding to a position below the means 61 and 62. And at this machining position, among the multiple division planned lines intersecting between the devices 2, all sides that extend in one direction are first cut, and then all the division planned lines on the side extending in the other direction are cut, The wafer 1 is diced into a number of devices 2. The division lines to be cut are determined in parallel with the X-axis direction by rotating the chuck table 20 and rotating the wafer 1.

  In the cutting process, the cutting blade 65 whose lower edge is set at a predetermined cutting height (position in the Z-axis direction) while moving the chuck table 20 in the X2 direction is rotated in the X2 direction with respect to the division line. This is done by performing a process feed for cutting from the end on the side toward the end on the X1 direction side. When one machining feed is completed, the cutting blade 65 is retracted upward, the chuck table 20 is moved in the X1 direction, the cutting blade 65 is returned to the starting point of the machining feed, and the cutting means 61 and 62 are moved in the Y-axis direction. Then, the indexing feed for aligning the cutting edge of the cutting blade 65 with the next division line is performed, and then the cutting blade 65 is processed and fed to the next division line. By performing the above operation, cutting is applied to all the division lines extending in the X-axis direction. In order to position the cutting blade 65 on the planned dividing line, a known alignment means using a camera or the like is used.

(2-3) Action of Air Curtain Unit and Pressure Sensor While the wafer 1 is being cut as described above, the outer peripheral nozzle 111 provided on the blade cover 100 and the cutting blade 65 and the wafer 1 Cutting fluid is ejected from the side nozzle 112, and the cutting fluid is supplied to a processing point where the cutting blade 65 cuts into the wafer 1. The cutting fluid cools the frictional heat generated when the cutting blade 65 cuts the wafer 1, and the cutting scraps are washed away from the processing point at which the cutting blade 65 cuts into the wafer 1 or the processing point is lubricated. To do.

  Further, during the cutting process, the pressure sensor 85 is activated. In the air pressure chamber 833 in which the pressure sensor 85 is disposed, the air immediately before forming the air curtain portion 75 through the gap 74 is temporarily stored. The pressure in the air pressure chamber 833 shows a value within a certain range in a state where no significant change occurs in the pressure in the air curtain portion 75.

  The cutting fluid supplied during cutting is splashed up from the processing point by the rotating cutting blade 65 and scattered around, but the scattering of the cutting fluid is suppressed to a short distance by the blade cover 100. The used cutting fluid scattered by the rotating cutting blade 65 is mixed with cutting waste generated by the cutting process, and is in a sewage state.

  The dirty cutting fluid splashed up by the rotating cutting blade 65 is also scattered in the direction of the air spindle unit 70. On the other hand, in the air spindle unit 70, the motor 71 is operated while high-pressure air is always supplied from the air supply port 813 into the housing 80, and the radial between the outer peripheral surface of the rotating shaft 90 and the inner peripheral surface of the housing 80. An air bearing 72 is formed, and a thrust air bearing 73 is formed between the side surface of the flange 92 and the ring 82. Thereby, the rotating shaft 90 is supported in a state where a certain distance is maintained between the rotating shaft 90 and the housing 80 during rotation.

  A part of the air that has passed through the space between the rotary shaft 90 and the housing 80 to form the bearings 72 and 73 is an opening on the tip side of the air spindle unit 70, that is, the blade mount 66 and the housing 80. The air curtain portion 75 is formed by ejecting from the gap 74 with the cap 83. By forming the air curtain portion 75, the cutting fluid splashing toward the tip of the air spindle unit 70 is prevented from being further scattered by the air curtain portion 75 and prevented from entering the gap 74. . For this reason, it is difficult for cutting waste to adhere to the blade mount 66 on both sides of the gap 74 and the cap 83 of the housing 80 and solidify.

  However, when the cutting process is performed for a long time, the function of preventing the cutting fluid from entering the air curtain part 75 becomes insufficient, and the cutting waste adheres and accumulates on the peripheral part of the gap 74 in the cap 83 of the blade mount 66 or the housing 80. The gap 74 may become narrow. When the air spindle unit 70 is operated in a state in which the deposits due to the cutting scraps are solidified, the gap 74 is narrowed, so that a pressure change occurs in which the pressure in the air pressure chamber 833 increases, and the pressure increase is detected by the pressure sensor. 85.

  Here, a threshold value for determining that the gap 74 is narrowed is set in advance to the pressure detected by the pressure sensor 85, and when the pressure indicated by the pressure sensor 85 exceeds the threshold value, the air curtain It may be determined that the air curtain portion 75 has been narrowed by cutting dust adhering to at least one of the blade mount 66 and the housing 80 around the portion 75.

  By proceeding with the operation while comparing the pressure of the air pressure chamber 833 with the threshold value in this way, even if a complicated operation such as removing the cutting blade 65 and the blade mount 66 is not performed, cutting waste is generated on the blade mount 66 and the cap 83. It is possible to easily detect that the gap 74 has been narrowed due to adhesion, and that the function of the air curtain unit 75 has deteriorated.

1 ... wafer (work)
10 ... Cutting device 20 ... Chuck table (holding table)
65 ... Cutting blade 66 ... Blade mount 70 ... Air spindle unit 75 ... Air curtain unit 80 ... Housing 813 ... Air supply port 833 ... Air pressure chamber 85 ... Pressure sensor (air pressure detection unit)
90 ... Rotating shaft

Claims (1)

An air spindle unit having a rotating shaft, a housing that supports the rotating shaft with air, and an air supply port for supplying air to a space formed between the rotating shaft and the housing;
A blade mount attached to the tip of the rotating shaft;
A cutting blade attached to the blade mount;
A holding table for holding a workpiece to be cut by the cutting blade;
A cutting device comprising:
Air supplied from the air supply port passes through a space between the rotating shaft and the housing, and is ejected from a gap formed between the housing and the blade mount attached to the tip of the rotating shaft. An air curtain part formed by
An air pressure chamber formed between the rotating shaft and the housing, and showing a pressure change according to the pressure of air in the air curtain portion;
An air pressure detector for detecting the air pressure in the air pressure chamber;
A cutting apparatus comprising:

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