Cutting method for workpiece

Abstract

To prevent both chipping of a chip and adhesion of cutting waste to the chip.SOLUTION: After a second cutting step, a washing step of washing the upper surface of a wafer 100 and a second cutting groove is performed. Thus, it is possible to prevent cutting waste from remaining in the second cutting groove and adhering to a chip. In addition, an amount of first cutting water 301 supplied in the second cutting step is made smaller than an amount of first cutting water 301 supplied in the washing step. Accordingly, in the second cutting step, it is possible to satisfactorily prevent a formed chip 116 from being moved due to the influence of the first cutting water 301, with the result that the chip 116 comes into contact with a rotating cutting blade 63, resulting in occurrence of chipping.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a cutting method for cutting a workpiece. [Background technology]

[0002] In the process of cutting a workpiece with a cutting blade to make chips, cutting water is supplied to the processing point for cooling and removal of cutting debris (contamination) (see Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-076823 [Patent Document 2] Patent Publication No. 2680453 Summary of the Invention [Problem to be solved by the invention]

[0004] However, especially when the chip size is small, the influence of the cutting water can cause the chip to move and chipping can occur. Reducing the amount of cutting water reduces chipping, but it makes it difficult for cutting chips to be discharged, and cutting chips can remain on the surface or side of the chip.

[0005] An object of the present invention is to provide a cutting method that can suppress both chipping of the tip and adhesion of cutting debris to the tip. [Means for solving the problem]

[0006] A first workpiece cutting method (first cutting method) of the present invention is a method for dividing a workpiece into a plurality of chips using a cutting device including a holding table for holding the workpiece, a cutting unit rotatably supporting a cutting blade for cutting the workpiece, a cutting water supply unit for supplying cutting water to the cutting blade, and a processing feed unit for moving the holding table in a processing feed direction relative to the cutting blade, the method including a first cutting step of aligning a plurality of first planned division lines formed in a first direction in parallel with the X-axis direction, and moving the holding table in the -X direction relative to the cutting blade to cut the workpiece along the first planned division lines, and after the first cutting step is performed, By rotating the holding table, The method includes a second cutting step in which a plurality of second planned division lines formed in a second direction intersecting the first direction are parallel to the X-axis direction, and the holding table is moved in the -X direction relative to the cutting blade to cut the workpiece along the second planned division lines, thereby dividing the workpiece into chips; and a cleaning step that is performed each time the workpiece is cut along one of the second planned division lines in the second cutting step, in which the holding table is moved in the +X direction relative to the cutting blade and the cutting water is applied to at least one of the cut grooves formed in the second cutting step or the periphery of the cut grooves, while cleaning the upper surface of the workpiece and the cut grooves, and in which the amount of cutting water supplied in the second cutting step is less than the amount of cutting water supplied in the first cutting step and the cleaning step, and is sufficient to prevent the chips from moving. In the cleaning step, the cutting water applied to at least either the cutting groove formed in the second cutting step or the periphery of the cutting groove may include cutting water supplied from the cutting water supply unit to the cutting blade and splashed from the cutting blade due to the rotation of the cutting blade. A second workpiece cutting method (second cutting method) of the present invention is a method for dividing a workpiece into a plurality of chips using a cutting device including a holding table for holding the workpiece, a cutting unit rotatably supporting a cutting blade for cutting the workpiece, a cutting water supply unit for supplying cutting water to the cutting blade, and a processing feed unit for moving the holding table in a processing feed direction relative to the cutting blade, the method including a first cutting step for cutting the workpiece along a plurality of first planned division lines formed in a first direction, and, after the first cutting step, cutting the workpiece along a plurality of second planned division lines formed in a second direction intersecting the first direction. and a cleaning step in which the upper surface of the workpiece and the cutting groove are cleaned while applying the cutting water to at least one of the cutting grooves formed in the second cutting step or the periphery of the cutting grooves, wherein in the second cutting step, the cutting water is supplied at a supply angle that is more parallel to the upper surface of the workpiece than the supply angle of the cutting water supplied in the first cutting step and the cleaning step, and the cutting device has at least two cutting water supply units that supply the cutting water at different supply angles to the upper surface of the workpiece, and the supply angle of the cutting water is switched by switching the cutting water supply unit to be used. [Effects of the Invention]

[0007] In the present invention, after the second cutting step, a cleaning step is performed to clean the cut groove formed in the second cutting step. Therefore, the cut groove formed in the second cutting step can be cleaned well. This makes it possible to prevent cutting debris from remaining in the cut groove and adhering to the tip.

[0008] Furthermore, in the present invention, the amount of cutting water supplied in the second cutting step is smaller than the amount of cutting water supplied in the cleaning step, or the cutting water is supplied at an angle that is more parallel to the top surface of the workpiece than the angle at which the cutting water is supplied in the cleaning step, thereby reducing the effect of the cutting water on the top surface of the workpiece in the second cutting step compared to the cleaning step.

[0009] Therefore, in the second cutting step in which the workpiece is divided to form chips, it is possible to effectively prevent the formed chips from moving due to the influence of the cutting water, and from coming into contact with the rotating cutting blade and causing chipping. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a perspective view showing a work set including a wafer. [Figure 2] FIG. 2 is a perspective view showing the configuration of a cutting device. [Figure 3] FIG. 2 is a perspective view showing the configuration of a cutting unit. [Figure 4] FIG. 2 is a perspective view showing the configuration of a cutting water supply unit. [Figure 5] FIG. 4 is an explanatory diagram showing a first cutting step and a second cutting step. [Figure 6] FIG. 10 is an explanatory diagram showing a cleaning step. [Figure 7] FIG. 2 is an explanatory diagram showing cutting water used in the first cutting step, the second cutting step, and the cleaning step. [Figure 8] FIG. 10 is an explanatory view showing a second cutting step. [Figure 9] FIG. 10 is an explanatory view showing the cutting water used in the second cutting step. [Figure 10] FIG. 10 is a perspective view showing another configuration of the cutting water supply unit. DETAILED DESCRIPTION OF THE INVENTION

[0011] In the chip spacing forming method according to this embodiment, a wafer 100 as shown in Fig. 1 is used as a workpiece. The wafer 100 has a circular shape, and on its surface are formed a plurality of first planned division lines 103 extending in a first direction and a plurality of second planned division lines 104 extending in a second direction perpendicular to the first direction. Devices 101 are formed in each of the regions partitioned by these first planned division lines 103 and second planned division lines 104.

[0012] In this embodiment, the wafer 100 is handled in the state of a work set 110. The work set 110 is formed by integrating an annular frame 111 having an opening 112 capable of accommodating the wafer 100 with the wafer 100 positioned in the opening 112 of the annular frame 111 using a dicing tape 113. In this embodiment, the wafer 100 is processed in the state of this work set 110 by the cutting device 1 shown in FIG.

[0013] 2 performs cutting processing on such a wafer 100. In this embodiment, the cutting processing by the cutting device 1 is a dicing processing in which the wafer 100 is divided along first planned division lines 103 and second planned division lines 104 to form a plurality of chips.

[0014] The cutting device 1 includes a base 10, a gate-type column 11 erected on the base 10, and a control unit 7 that controls each member of the cutting device 1.

[0015] The control unit 7 includes a CPU that performs calculations according to a control program, and a storage medium such as a memory, etc. The control unit 7 controls each member of the cutting device 1 to perform cutting processing on the wafer 100.

[0016] A processing feed unit 14 is disposed on the base 10. The processing feed unit 14 moves the holding section 3 including the holding table 30 relative to the cutting blade 63 (see FIG. 3) of the cutting unit 6 along a horizontal direction (processing feed direction; X-axis direction) parallel to the holding surface 32 of the holding table 30.

[0017] The processing feed unit 14 includes a pair of guide rails 141 extending in the X-axis direction, an X-axis table 143 placed on the guide rails 141, a ball screw 140 extending parallel to the guide rails 141, and a motor 142 that rotates the ball screw 140.

[0018] A pair of guide rails 141 are arranged on the upper surface of the base 10 parallel to the X-axis direction. The X-axis table 143 is installed on the pair of guide rails 141 so as to be slidable along these guide rails 141. The holder 3 is placed on the X-axis table 143.

[0019] The ball screw 140 is threadedly engaged with a nut portion (not shown) provided on the X-axis table 143. The motor 142 is connected to one end of the ball screw 140 and rotates the ball screw 140. When the ball screw 140 is rotated, the X-axis table 143 and the holder 3 move along the guide rail 141 in the X-axis direction, which is the processing feed direction.

[0020] The holding unit 3 includes a holding table 30 that holds the wafer 100 of the work set 110, a cover plate 34 that is disposed around the holding table 30, and two clamps 33 that are provided around the holding table 30. The holding unit 3 also includes a θ table 31 below the cover plate 34 that supports and rotates the holding table 30.

[0021] The holding table 30 is a member that holds the wafer 100 shown in FIG. 1 and is formed in a disk shape. The holding table 30 has a holding surface 32 made of a porous material. The holding surface 32 can be connected to a suction source (not shown). The holding table 30 holds the wafer 100 by suction using this holding surface 32.

[0022] The holding table 30 is supported by a θ table 31 disposed on the bottom side of the holding table 30. The θ table 31 is provided on the upper surface of the X-axis table 143 so as to be rotatable within the XY plane. Therefore, the θ table 31 not only supports the holding table 30, but also can rotate the holding table 30 within the XY plane.

[0023] The cover plate 34 is disposed below and around the holding table 30. The cover plate 34 is provided with, for example, a bellows cover (not shown) for covering the components below the holding table 30 together with the cover plate 34.

[0024] A gate-type column 11 is erected on the rear side (-X direction side) of the base 10 so as to straddle the processing feed unit 14. A cutting unit moving mechanism 13 that moves the cutting unit 6 is provided on the front side (+X direction side) of the gate-type column 11.

[0025] The cutting unit moving mechanism 13 indexes and feeds the cutting unit 6 in the Y-axis direction and incision feeds in the Z-axis direction. The cutting unit moving mechanism 13 includes an indexing feed mechanism 12 that moves the cutting unit 6 in the indexing feed direction (Y-axis direction), and an incision feed mechanism 16 that moves the cutting unit 6 in the incision feed direction (Z-axis direction).

[0026] The indexing feed mechanism 12 is disposed in front of the gantry column 11. The indexing feed mechanism 12 adjusts the position of the cutting unit 6 in the Y-axis direction by reciprocating the incision feed mechanism 16 and the cutting unit 6 along the Y-axis direction.

[0027] The indexing feed mechanism 12 includes a pair of guide rails 121 extending in the Y-axis direction, a Y-axis table 123 placed on the guide rails 121, a ball screw 120 extending parallel to the guide rails 121, and a motor 122 that rotates the ball screw 120.

[0028] A pair of guide rails 121 are arranged parallel to the Y-axis direction on the front surface of the gate-type column 11. The Y-axis table 123 is installed on the pair of guide rails 121 so as to be slidable along these guide rails 121. The cutting feed mechanism 16 and the cutting unit 6 are attached to the Y-axis table 123.

[0029] The ball screw 120 is threadedly engaged with a nut portion (not shown) provided on the Y-axis table 123. The motor 122 is connected to one end of the ball screw 120 and rotates the ball screw 120. When the ball screw 120 is rotated, the Y-axis table 123, the incision feed mechanism 16, and the cutting unit 6 move along the guide rail 121 in the Y-axis direction, which is the indexing feed direction.

[0030] The cutting feed mechanism 16 reciprocates the cutting unit 6 along the Z-axis direction (up and down direction). The Z-axis direction is perpendicular to the X-axis direction and the Y-axis direction, and is also perpendicular to the holding surface 32 of the holding table 30.

[0031] The cutting feed mechanism 16 includes a pair of guide rails 161 extending in the Z-axis direction, a support member 163 placed on the guide rails 161, a ball screw 160 extending parallel to the guide rails 161, and a motor 162 that rotates the ball screw 160.

[0032] A pair of guide rails 161 are arranged on the Y-axis table 123 parallel to the Z-axis direction. A support member 163 is installed on the pair of guide rails 161 so as to be slidable along these guide rails 161. A cutting unit 6 is attached to the lower end of the support member 163.

[0033] The ball screw 160 is threadedly engaged with a nut portion (not shown) provided on the back side of the support member 163. The motor 162 is connected to one end of the ball screw 160 and rotates the ball screw 160. When the ball screw 160 is rotated, the support member 163 and the cutting unit 6 move along the guide rail 161 in the Z-axis direction, which is the cutting feed direction.

[0034] The cutting unit 6 cuts the wafer 100 held on the holding table 30, and rotatably supports a cutting blade 63 that cuts the wafer 100.

[0035] As shown in Figure 3, the cutting unit 6 includes a spindle 60, a housing 61 that rotatably supports the spindle 60, a cutting blade 63 attached to the spindle 60, a motor (not shown) that rotates the spindle 60, and a first blade cover 64 and a second blade cover 65 that surround the cutting blade 63.

[0036] The spindle 60 extends in the Y-axis direction along a spindle rotation axis 601 indicated by a dashed line. The cutting blade 63 is attached to the tip of the spindle 60 via a mount flange 630. The cutting blade 63 is an annular blade having an annular cutting edge (cutting edge) 631 on its outer periphery. The cutting edge 631 is formed, for example, by fixing diamond abrasive grains or the like with an appropriate binder.

[0037] In the cutting unit 6, the motor rotates the spindle 60 at high speed, which also rotates the cutting blade 63 at high speed. The cutting blade 63, which rotates at high speed, performs cutting on the wafer 100.

[0038] The first blade cover 64 is supported by the housing 61 so as to cover the -X direction side above the cutting blade 63. The second blade cover 65 is supported by the housing 61 so as to cover the +X direction side above the cutting blade 63. A cutting water supply unit 70 is provided on the +X direction side of the second blade cover 65.

[0039] As shown in Figures 3 and 4, the cutting water supply unit 70 has a first block 71 having a first outlet 73, a second block 72 having a second outlet 74, and a block connecting member 79 connecting the first block 71 and the second block 72.

[0040] The first block 71 is provided with an attachment member 78 for attaching the cutting water supply unit 70 to the second blade cover 65, as well as a first water supply joint 76 and a second water supply joint 77 that can be connected to a water supply source not shown.

[0041] The first water supply joint 76 is connected to the first outlet 73 via a water supply passage (not shown) provided in the first block 71. Meanwhile, the second water supply joint 77 is connected to the second outlet 74 via a water supply passage (not shown) provided in the first block 71, the block connecting member 79, and the second block 72.

[0042] The first jet nozzle 73 uses water supplied from a water supply source via a first water supply joint 76 to jet cutting water obliquely upward toward the contact portion (processing point) between the cutting blade 63 and the wafer 100. The second nozzle 74 uses water supplied from a water supply source via the second water supply joint 77 to spray cutting water onto the processing point of the cutting blade 63 at an angle close to horizontal to the top surface of the wafer 100, which is the workpiece.

[0043] Hereinafter, the cutting water supplied to the machining point from the first nozzle 73 will also be referred to as the “first cutting water.” Also, the cutting water supplied to the machining point from the second nozzle 74 will also be referred to as the “second cutting water.” The first nozzle 73 and the second nozzle 74 are examples of a cutting water supply unit that supplies cutting water to the cutting blade 63.

[0044] The lower end of the block connecting member 79 is fixed to the second block 72. The upper end of the block connecting member 79 is inserted into the first block 71 so as to be movable along the Z-axis direction. The block connecting member 79 can be fixed at any position within the first block 71 by a fixing mechanism 80 having a screw provided in the first block 71.

[0045] Therefore, in this embodiment, by adjusting the position of the block connecting member 79 within the first block 71, the worker can adjust the height position of the second block 72 fixed to the block connecting member 79, i.e., the height position of the second outlet 74 provided in the second block 72.

[0046] As shown in FIG. 3 , a blade cooling unit 90 is provided on the side surface of the first blade cover 64 on the −X direction side. The blade cooling unit 90 supports a pair of blade cooling nozzles 91 that are approximately L-shaped when viewed from the −Y direction side. The blade cooling nozzles 91 are arranged to sandwich the cutting blade 63 and supply cutting water to the cutting blade 63 for cooling and cleaning the cutting blade 63. The pair of blade cooling nozzles 91 can be connected to a water supply source (not shown) via a pair of third water supply joints 93. The blade cooling nozzles 91 are an example of a cutting water supply unit that supplies cutting water to the cutting blade 63.

[0047] In the following, the cutting water supplied from the blade cooling nozzle 91 to the cutting blade 63 is also referred to as blade cutting water. The blade cutting water is supplied to the front and back surfaces of the cutting blade 63 from approximately the entire blade cooling nozzle 91 extending in the X-axis direction.

[0048] A method for dividing the wafer 100 into a plurality of chips using the cutting device 1 will be described below.

[0049] [Hold Step] In this step, an operator places the wafer 100 of the work set 110 shown in FIG. 1 on the holding table 30 of the holding unit 3 shown in FIG. 2 via dicing tape 113. Furthermore, as shown in FIG. 5, the operator supports the annular frame 111 of the work set 110 with the clamps 33 of the holding unit 3. In this state, the control unit 7 connects the holding surface 32 of the holding table 30 to a suction source (not shown), thereby suction-holding the wafer 100 with the holding surface 32. In this manner, the work set 110 including the wafer 100 is held by the holding unit 3.

[0050] [First cutting step] In this step, the wafer 100, which is the workpiece, is cut along a plurality of first dividing lines 103 (see FIG. 1) formed in a first direction.

[0051] Specifically, first, the control unit 7 controls the θ table 31 of the holding unit 3 to rotate the holding table 30 so that the first planned dividing line 103 of the wafer 100 held on the holding surface 32 of the holding table 30 is parallel to the X-axis direction. Thereafter, the control unit 7 controls the processing feed unit 14 shown in FIG. 2 to position the holding unit 3 at a predetermined cutting start position below the cutting unit 6.

[0052] Furthermore, the control unit 7 controls the indexing mechanism 12 of the cutting unit moving mechanism 13 to align the position of the cutting blade 63 in the Y-axis direction with one of the first planned dividing lines 103 on the wafer 100 .

[0053] Thereafter, the control unit 7 controls the cutting feed mechanism 16 while rotating the cutting blade 63 at high speed to lower the cutting blade 63 of the cutting unit 6 to a predetermined cutting height for cutting (severing) the wafer 100 held by suction on the holding surface 32.

[0054] In this state, the control unit 7 controls the processing feed unit 14 to move the holder 3 holding the work set 110 in the -X direction as indicated by arrow 501, as shown in Fig. 5. As a result, the cutting blade 63 rotating as indicated by arrow 505 cuts the wafer 100 along one of the first planned division lines 103. As a result, a first cutting groove (not shown) that is a cutting groove along the first planned division line 103 is formed in the wafer 100. Note that the cutting water supply unit 70 and the blade cooling unit 90 are not shown in Fig. 5 and Fig. 6, which will be described later.

[0055] Thereafter, the control unit 7 controls the cutting feed mechanism 16 to position the cutting blade 63 above and away from the wafer 100, as shown in FIG. 6. Furthermore, the control unit 7 controls the processing feed unit 14 to move the holder 3 in the +X direction as indicated by arrow 502, returning it to the cutting start position. Then, the control unit 7 controls the indexing feed mechanism 12 to align the position of the cutting blade 63 in the Y-axis direction with another first planned dividing line 103 to be cut next on the wafer 100, and cuts the wafer 100 along this first planned dividing line 103.

[0056] In this manner, the control unit 7 cuts the wafer 100 along all of the first planned dividing lines 103 on the wafer 100. In the first cutting step, the control unit 7 may perform indexing before returning the holding unit 3 to the cutting start position. That is, after forming one first cutting groove, the control unit 7 may use the indexing mechanism 12 to align the position of the cutting blade 63 in the Y-axis direction with the first planned division line 103 to be cut next, and then return the holding unit 3 to the cutting start position.

[0057] Furthermore, when the cutting blade 63 cuts the wafer 100 along the first planned division line 103, the control unit 7 connects the water supply source to the first nozzle 73 provided in the first block 71 of the cutting water supply unit 70 shown in FIG. 4 via the first water supply joint 76. As a result, as shown in FIG. 7, a predetermined first volume of first cutting water 301 is jetted from the first nozzle 73 obliquely upward toward the processing point, which is the contact point between the cutting blade 63 and the wafer 100, to clean the first cut groove formed by cutting. Note that this first volume of water is, for example, a volume sufficient to effectively remove cutting debris from within the first cut groove. In the first cutting step, the wafer 100, which is the workpiece, is not singulated into chips but is cut into rectangular pieces. Therefore, the resulting rectangular pieces are less likely to move than the chips. Therefore, the first volume of water can be supplied in a sufficient amount suitable for cleaning.

[0058] Furthermore, the control unit 7 connects the water supply source to the pair of blade cooling nozzles 91 in the blade cooling unit 90 via the third water supply joint 93. As a result, the cutting blade 63 is sandwiched between the blade cooling nozzles 91, and blade cutting water 305 is sprayed onto both sides of the cutting blade 63, thereby cooling and cleaning the cutting blade 63.

[0059] [Second cutting step] This step is performed after the first cutting step, in which the wafer 100 is divided into a plurality of chips by cutting the wafer 100 along a plurality of second dividing lines 104 formed in a second direction intersecting the first direction.

[0060] Specifically, first, the control unit 7 controls the θ table 31 of the holding unit 3 to rotate the holding table 30 so that the second planned dividing line 104 of the wafer 100 held on the holding surface 32 of the holding table 30 is parallel to the X-axis direction. Thereafter, similar to the first cutting step, the control unit 7 controls the processing feed unit 14 to position the holding unit 3 holding the wafer 100 of the work set 110 at a predetermined cutting start position below the cutting unit 6.

[0061] Furthermore, the control unit 7 controls the indexing mechanism 12 of the cutting unit moving mechanism 13 to align the position of the cutting blade 63 in the Y-axis direction with one of the second planned dividing lines 104 on the wafer 100 .

[0062] Thereafter, the control unit 7 controls the cutting feed mechanism 16 while rotating the cutting blade 63 at high speed to lower the cutting blade 63 of the cutting unit 6 to a predetermined cutting height for cutting the wafer 100 held by suction on the holding surface 32.

[0063] In this state, the control unit 7 controls the processing feed unit 14 to move the holding unit 3 in the X-axis direction (arrow 501), as in the first cutting step, as shown in Fig. 5. This causes the cutting blade 63 to cut the wafer 100 along the second planned dividing line 104.

[0064] 8, second cut grooves 115, which are cut grooves along the second planned division lines 104, are formed in the wafer 100. This causes the wafer 100 to be divided into chips 116, each including one device 101, by the second cut grooves 115 and the first cut grooves already formed in the first cutting step.

[0065] In addition, when cutting the wafer 100 along the second planned dividing line 104 using the cutting blade 63, the control unit 7 sprays first cutting water 301 from the first nozzle 73 diagonally upward toward the processing point, which is the contact point between the cutting blade 63 and the wafer 100, for cleaning the second cutting groove 115, as in the first cutting step, and sprays blade cutting water 305 from the blade cooling nozzle 91 toward the cutting blade 63 for cooling and cleaning the cutting blade 63.

[0066] At this time, since the wafer 100, which is the workpiece, has been divided into chips 116, these chips are more likely to move than the rectangular pieces produced in the first cutting step, and there is a risk that the chips 116 will come into contact with each other and break. Therefore, the control unit 7 sets the amount of water in the first cutting water 301 to a predetermined second amount of water. This second amount of water is less than the above-mentioned first amount of water, and is, for example, an amount that can sufficiently prevent the formed chips 116 from moving due to the influence of the first cutting water 301.

[0067] [Cleaning step (clean cut)] This step is performed after cutting the wafer 100 along one second planned dividing line 104 by the cutting blade 63 (i.e., after forming one second cut groove 115). In the second cutting step, the amount of first cutting water 301 is limited to a smaller amount than in the first cutting step in order to suppress movement of the chip 116. This has the effect of preventing the chip 116 from moving, but there is a risk that processing debris may remain attached to the second cut groove 115 and the surrounding area of ​​the second cut groove 115. Therefore, in the cleaning step, at least either the top surface of the wafer 100 or the second cutting groove 115 formed in the second cutting step is cleaned while applying cutting water to at least either the second cutting groove 115 or the area around the second cutting groove 115.

[0068] Specifically, after forming one second cut groove 115 in the second cutting step, the control unit 7 controls the cutting feed mechanism 16 to move the cutting blade 63 away from the wafer 100 and position it, for example, several millimeters above the top surface of the wafer 100, as shown in Fig. 6. Furthermore, the control unit 7 controls the processing feed unit 14 to return the holding part 3 to the cutting start position. As a result, the cutting unit 6 moves relative to the wafer 100 along the second cut groove 115 formed in the second cutting step.

[0069] At this time, the control unit 7 connects the water supply source to the first jetting port 73 (see FIG. 4), and jets the first cutting water 301 onto the wafer 100 from an obliquely upward direction, as shown in FIG. 7, toward the second cut groove 115 formed in the wafer 100 in the second cutting step and the periphery of the second cut groove 115. As a result, when the holder 3 is returned to the cutting start position, the upper surface of the wafer 100 and the second cut groove 115 formed in the wafer 100 and the periphery thereof are cleaned.

[0070] At this time, the control unit 7 sets the amount of first cutting water 301 to a predetermined third amount of water. This third amount of water is larger than the second amount of water described above, and is, for example, an amount of water that can satisfactorily remove cutting debris from within the second cut groove 115. This third amount of water may be the same as, smaller than, or larger than the first amount of water, which is the amount of first cutting water 301 in the first cutting step, as long as it is an amount of water that can effectively perform cleaning.

[0071] After returning the holding part 3 to the cutting start position, the control part 7 controls the indexing feed mechanism 12 to align the position of the cutting blade 63 in the Y-axis direction with another second planned dividing line 104 on the wafer 100, and performs a second cutting step and a cleaning step for this second planned dividing line 104.

[0072] In this way, the control unit 7 performs the second cutting step and cleaning step for each second planned division line 104 on the wafer 100, thereby dividing the entire wafer 100 into chips 116 each including one device 101.

[0073] As described above, in this embodiment, after the second cutting step, a cleaning step is performed to clean at least one of the upper surface of the wafer 100 and the second cut groove 115. Therefore, the second cut groove 115 formed in the second cutting step and its surroundings can be cleaned well. This makes it possible to prevent cutting debris from remaining in or around the second cut groove 115 and adhering to the chip 116.

[0074] In this embodiment, in the second cutting step, the amount of water ( 2nd water volume ) is supplied to the machining point. That is, the amount of first cutting water 301 in the second cutting step is set to be less than the amount of first cutting water 301 in the cleaning step. As a result, in the second cutting step, the influence of the first cutting water 301 on the upper surface of the wafer 100 is smaller than in the cleaning step. Therefore, in the second cutting step in which the wafer 100 is divided to form chips 116, the formed chips 116 are effectively prevented from moving due to the influence of the first cutting water 301 and coming into contact with the rotating cutting blade 63, resulting in chipping.

[0075] In this embodiment, during the cleaning step, the control unit 7 moves the cutting blade 63 along the second cut groove 115 relative to the wafer 100 while separating it from the wafer 100, as shown in FIG. 6 . In this regard, during the cleaning step, the control unit 7 may move the cutting blade 63 along the second cut groove 115 relative to the wafer 100 while a portion of the rotating cutting blade 63 is inserted (cutting) into the second cut groove 115. In this case, the height of the cutting blade 63 is set, for example, to the same height as that during the second cutting step, or slightly shallower to prevent tape debris from being generated or the cutting blade 63 from contacting the side surface of the chip 116. In this configuration, cutting debris within the second cut groove 115 can be removed by the rotating cutting blade 63, thereby enhancing the cleaning power during the cleaning step.

[0076] In this case, it is preferable to set the moving speed of the cutting blade 63 relative to the wafer 100 (specifically, the moving speed when the processing feed unit 14 returns the holding part 3 to the cutting start position) slower than the moving speed of the cutting blade 63 when it is separated from the wafer 100. This makes it possible to prevent the cutting blade 63 from damaging the tip 116 when the cutting blade 63 moves in the Y-axis direction or when the tip 116 is moved by the first cutting water 301.

[0077] In addition, after cutting the wafer 100 along one first planned dividing line 103 in the first cutting step (i.e., after forming one first cutting groove), a cleaning step similar to the cleaning step described above may be performed.

[0078] In this embodiment, as shown in FIG. 9, second cutting water 302 may be ejected from second ejection nozzle 74 instead of first ejection nozzle 73 in the second cutting step. In this case, for example, the worker adjusts the position of the block connecting member 79 within the first block 71 in the cutting water supply unit 70 shown in Figure 4 to bring the height position of the second outlet 74 provided in the second block 72 closer to the machining point. Then, when the cutting blade 63 cuts the wafer 100 along the second planned dividing line 104, the control unit 7 connects the water supply source to the second jetting port 74 via the second water supply joint 77. As a result, as shown in Fig. 9, the second cutting water 302 is jetted from the second jetting port 74 in a direction substantially parallel to the upper surface of the wafer 100 toward the processing point, which is the contact point between the cutting blade 63 and the wafer 100.

[0079] Thus, in this configuration, in the second cutting step, the second cutting water 302 is supplied at a supply angle that is more parallel to the top surface of the wafer 100 than the supply angle of the first cutting water 301 supplied in the cleaning step. In other words, the supply angle of the second cutting water 302 supplied in the second cutting step is more parallel to the top surface of the wafer 100 than the supply angle of the first cutting water 301 supplied in the cleaning step.

[0080] In this regard, the closer the incident direction of the cutting water to the top surface of the wafer 100 is to perpendicular, the stronger the cleaning power of the cutting water to the top surface of the wafer 100. On the other hand, the closer the incident direction of the cutting water to parallel to the top surface of the wafer 100, the smaller the effect of the cutting water on the top surface of the wafer 100. For this reason, by spraying the second cutting water 302 onto the wafer 100 instead of the first cutting water 301 in the second cutting step as described above, it is possible to effectively prevent the chips 116 formed in this step from moving due to the effect of the cutting water and from coming into contact with the rotating cutting blade 63 and causing chipping.

[0081] Even in this case, in the cleaning step performed after the second cutting step, the first cutting water 301 is supplied to the wafer 100 from diagonally above, thereby enabling the second cutting groove 115 formed in the second cutting step and its surroundings to be cleaned well.

[0082] Furthermore, in this embodiment, the cutting device 1 has at least two cutting water supply units, a first nozzle 73 and a second nozzle 74, which supply cutting water at different supply angles relative to the top surface of the wafer 100. In the above method, the control unit 7 switches the nozzle to be used at least between the second cutting step and the cleaning step. Therefore, the supply angle of cutting water relative to the top surface of the wafer 100 can be changed between the cutting step and the cleaning step without replacing the cutting water supply unit 70. This can improve work efficiency.

[0083] When the second cutting water 302 is used in the second cutting step, the amount of the second cutting water 302 may be any amount that can prevent the chip 116 from moving due to the second cutting water 302, and may be the same as the amount of the first cutting water 301 (third amount of water) in the cleaning step, or may be less than the third amount of water.

[0084] In this embodiment, the cutting device 1 has a first outlet 73 provided in the first block 71 and a second outlet 74 provided in the second block 72 as cutting water supply units that supply cutting water to the cutting blade 63. In this regard, the cutting device 1 may be provided with a pipe-shaped nozzle as the cutting water supply unit instead of these outlets. For example, the cutting device 1 may have a nozzle in the first block 71 that sprays cutting water obliquely from above toward the processing point, instead of the first jet nozzle 73. Furthermore, the cutting device 1 may have a nozzle in the second block 72 that sprays cutting water toward the processing point at an angle nearly horizontal to the upper surface of the wafer 100, instead of the second jet nozzle 74.

[0085] The cutting device 1 also includes a first jet nozzle 73 and a second jet nozzle 74 as a cutting water supply unit that supplies cutting water at different supply angles relative to the upper surface of the wafer 100. In this regard, the shapes and installation positions of the first jet nozzle 73 and the second jet nozzle 74 are not limited to those shown in Fig. 4, as long as cutting water can be supplied at different supply angles relative to the upper surface of the wafer 100. The cutting device 1 may also include three or more types of jet nozzles or nozzles as a cutting water supply unit, in addition to the two types of the first jet nozzle 73 and the second jet nozzle 74.

[0086] 10, the cutting water supply unit 70 may be provided with a plurality of third outlets 75 as downward-facing outlets on the underside of the second block 72. In this configuration, a fourth water supply joint 81 is provided in the second block 72. This fourth water supply joint 81 is connected to the third outlets 75 via a water supply passage (not shown) provided in the second block 72.

[0087] The multiple third jetting ports 75 are arranged in a row along the Y-axis direction on the underside of the second block 72. The third jetting ports 75 are connected to a water supply source via the fourth water supply joint 81, and are thereby able to jet cleaning water from a direction substantially perpendicular to the upper surface of the wafer 100. Therefore, in the cleaning step, by jetting cleaning water from the third jetting ports 75 onto the upper surface of the wafer 100, the upper surface of the wafer 100 can be cleaned with greater cleaning power.

[0088] In this embodiment, the supply of cutting water from the first jet nozzle 73 or the second jet nozzle 74 may be stopped in the second cutting step. That is, in the second cutting step, only the blade cutting water 305 from the blade cooling nozzle 91 may be supplied as cutting water. In this case, the effect of the cutting water on the top surface of the wafer 100 in the second cutting step can be further reduced. Therefore, the occurrence of chipping in the chip 116 can be more effectively suppressed. [Explanation of symbols]

[0089] 1: cutting device, 7: control unit, 10: base, 11: gate-type column, 3: holding unit, 30: holding table, 31: θ table, 32: holding surface, 33: clamp, 13: Cutting unit moving mechanism, 12: Indexing feed mechanism, 16: Cutting feed mechanism, 14: Processing feed unit, 6: cutting unit, 60: spindle, 61: housing, 63: cutting blade, 64: first blade cover, 65: second blade cover, 601: Spindle rotation axis, 630: Mount flange, 631: Cutting edge 70: cutting water supply unit, 71: first block, 72: second block, 73: 1st spout, 74: 2nd spout, 75: 3rd spout, 78: Mounting member, 79: Block connecting member, 80: Fixing mechanism, 90: blade cooling unit, 91: blade cooling nozzle, 76: First water supply joint, 77: Second water supply joint, 81: 4th water supply joint, 93: 3rd water supply joint, 100: wafer, 101: device, 103: First division planned line, 104: Second division planned line, 110: work set, 111: annular frame, 113: dicing tape, 115: second cutting groove, 116: chip, 301: First cutting water, 302: Second cutting water, 305: Blade cutting water

Claims

1. a holding table for holding the workpiece; a cutting unit that rotatably supports a cutting blade that cuts a workpiece; a cutting water supply unit that supplies cutting water to the cutting blade; a processing feed unit that moves the holding table relative to the cutting blade in a processing feed direction, a first cutting step in which a plurality of first planned division lines formed in a first direction are made parallel to the X-axis direction, and the holding table is moved in a −X direction relative to the cutting blade to cut the workpiece along the first planned division lines; a second cutting step in which, after the first cutting step is performed, the holding table is rotated so that a plurality of second planned division lines formed in a second direction intersecting the first direction are parallel to the X-axis direction, and the holding table is moved in the −X direction relative to the cutting blade to cut the workpiece along the second planned division lines, thereby dividing the workpiece into chips; a cleaning step that is carried out every time the workpiece is cut along one of the second planned division lines in the second cutting step, in which the upper surface of the workpiece and the cut groove are cleaned while the holding table is moved in the +X direction relative to the cutting blade and the cutting water is applied to at least one of the cut groove formed in the second cutting step or the periphery of the cut groove, In the second cutting step, the amount of cutting water supplied is less than the amount of cutting water supplied in the first cutting step and the cleaning step, and is such that the chip does not move. A method for cutting a workpiece.

2. In the cleaning step, the cutting water applied to at least either the cutting groove formed in the second cutting step or the periphery of the cutting groove includes cutting water supplied from the cutting water supply unit to the cutting blade and splashed from the cutting blade by the rotation of the cutting blade.

2. The method for cutting a workpiece according to claim 1.

3. a holding table for holding the workpiece; a cutting unit that rotatably supports a cutting blade that cuts a workpiece; a cutting water supply unit that supplies cutting water to the cutting blade; a processing feed unit that moves the holding table relative to the cutting blade in a processing feed direction, a first cutting step of cutting the workpiece along a plurality of first planned dividing lines formed in a first direction; a second cutting step of dividing the workpiece into chips by cutting the workpiece along a plurality of second planned division lines formed in a second direction intersecting the first direction after the first cutting step is performed; a cleaning step of cleaning the upper surface of the workpiece and the cut groove while applying the cutting water to at least one of the cut groove formed in the second cutting step and the periphery of the cut groove, In the second cutting step, the cutting water is supplied at a supply angle that is more parallel to the upper surface of the workpiece than the supply angle of the cutting water supplied in the first cutting step and the cleaning step; The cutting device has at least two cutting water supply units that supply the cutting water at different supply angles relative to the upper surface of the workpiece, By switching the cutting water supply unit to be used, the supply angle of the cutting water is switched. A method for cutting a workpiece.

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