Workpiece processing method and workpiece processing apparatus

Abstract

To provide a workpiece processing method and a workpiece processing apparatus, capable of reducing a risk of breakage of a device by suppressing chip jumping of an end material, and reducing a man hour.SOLUTION: A workpiece processing method for dividing a disk-shaped workpiece in which a chamfered part is formed along an outer peripheral edge and a plurality of division lines are set, along the division lines into individual device chips, includes: a tape attaching step of attaching a tape larger than an outer diameter of the workpiece to a front surface side or a back surface side of the workpiece; a filling step of filling a gap between the chamfered part formed on the outer peripheral edge of the workpiece and the tape with a filling member; and a cutting step of relatively moving the workpiece and a cutting blade to cut the workpiece along the division planned line after the filling step is performed, and dividing the workpiece into individual device chips.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for processing a workpiece.

Background Art

[0002] As a method for manufacturing a device chip, a method is known in which a workpiece such as a semiconductor wafer is cut along a plurality of planned division lines set on the workpiece to be fragmented into device chips. In such a method, for example, after attaching a dicing tape to the workpiece, the workpiece is held by a chuck table via the dicing tape, and the chuck table is fed for processing with the lower end of a cutting blade rotating at high speed positioned between the dicing tape and the holding surface, thereby cutting the workpiece.

[0003] Here, when a plurality of planned division lines are set in a grid pattern, substantially triangular or substantially trapezoidal end material chips having a curved side are formed near the outer peripheral edge of the workpiece. This end material chip has a smaller area compared to the device chip. Further, when a chamfered portion is formed on the outer peripheral edge of the workpiece, cutting water easily enters between the workpiece and the dicing tape during cutting. For this reason, so-called chip flutter occurs in which the end material chip peels off and scatters from the dicing tape during cutting, which may damage the device chip. Therefore, a method has been proposed in which cutting is performed with both sides of the workpiece sandwiched between tapes to suppress chip flutter of the end material chip (Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the above method, it is necessary to peel off the tape divided into device sizes by processing, which has the problem of taking a lot of man-hours.

[0006] The present invention has been made in view of such problems, and an object thereof is to provide a method and an apparatus for processing a workpiece that can suppress the flying of end material chips, reduce the risk of damage to the device, and reduce man-hours.

Means for Solving the Problems

[0007] In order to solve the above-described problems and achieve the object, a method for processing a workpiece according to the present invention is a method for processing a disk-shaped workpiece having a chamfered portion formed along an outer peripheral edge and a plurality of planned division lines set, the method comprising dividing the workpiece along the planned division lines into device chips, the method comprising: a tape attaching step of attaching a tape larger than the outer diameter of the workpiece to the front surface side or the back surface side of the workpiece; a filling step of filling a filling member into a gap between the chamfered portion formed on the outer peripheral edge of the workpiece and the tape; and a cutting step of relatively moving the workpiece and a cutting blade after performing the filling step, cutting the workpiece along the planned division line, and dividing the workpiece into device chips.

[0008] Further, the method for processing a workpiece according to the present invention further includes a detection step of detecting a region that becomes an end material chip, which is an end material of the device chip formed in the cutting step, before performing the filling step, and in the filling step, it is preferable to fill the filling member into the region that becomes the end material chip detected in the detection step.

[0009] In addition, the processing apparatus of the present invention includes a holding table that holds a disk-shaped workpiece having a chamfered portion formed along its outer peripheral edge and a tape larger than the outer diameter of the workpiece attached to the front or back surface thereof via the tape, a processing means having a cutting blade that performs cutting on the workpiece held by the holding table, and a moving means that relatively moves the holding table and the processing means, and further includes a filling member supply unit that fills a filling member into a gap between the chamfered portion formed on the outer peripheral edge of the workpiece and the tape.

[0010] In addition, the processing apparatus of the present invention preferably further includes a detection unit that detects a plurality of planned division lines set on the workpiece for individualizing the workpiece held by the holding table into device chips and a region that becomes an end material chip, which is an end material of the device chip, in the outer peripheral region of the workpiece.

Advantages of the Invention

[0011] The present invention can suppress the flying of end material chips, reduce the risk of device damage, and reduce man-hours.

Brief Description of the Drawings

[0012]

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[0013] A mode (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the content described in the following embodiments. Further, the constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Also, various omissions, substitutions, or changes in the configuration can be made without departing from the gist of the present invention.

[0014] Embodiment A method for processing a workpiece 10 and a processing apparatus 100 according to an embodiment of the present invention will be described with reference to the drawings. The method for processing the workpiece 10 according to the embodiment is a method for singulating the workpiece 10 shown in FIGS. 1 and 2 into device chips 17 by the processing apparatus 100 shown in FIG. 6.

[0015] <Workpiece 10> First, the configuration of the workpiece 10 to be processed in the method for processing the workpiece 10 according to the embodiment of the present invention will be described. FIG. 1 is a perspective view of the workpiece 10 to be processed in the method for processing the workpiece 10 according to the embodiment. FIG. 2 is a side view of the workpiece 10 shown in FIG. 1.

[0016] The workpiece 10 shown in FIGS. 1 and 2 is a wafer such as a disc-shaped semiconductor device wafer or an optical device wafer having a substrate 11 made of silicon (Si), sapphire (Al2O3), gallium arsenide (GaAs), silicon carbide (SiC), or lithium tantalate (LiTaO3). As shown in FIG. 2, the workpiece 10 has a chamfered portion 14 formed along the outer peripheral edge such that the center in the thickness direction protrudes most toward the outer peripheral side and has a circular arc-shaped cross section from the front surface 12 to the back surface 13 of the substrate 11.

[0017] The workpiece 10 has a plurality of division planned lines 15 set in a grid pattern and devices 16 formed on the front surface 12 of regions partitioned by the intersecting division planned lines 15. The devices 16 are, for example, integrated circuits such as IC (Integrated Circuit) or LSI (Large Scale Integration), or image sensors such as CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor).

[0018] The workpiece 10 is divided into individual devices 16 along the plurality of division planned lines 15 and separated into device chips 17. Note that the device chips 17 are square in the embodiment, but may be rectangular.

[0019] <Processing method of workpiece 10> Next, a method for processing the workpiece 10 according to an embodiment of the present invention will be described. FIG. 3 is a flowchart showing the flow of the method for processing the workpiece 10 according to the embodiment. The method for processing the workpiece 10 includes a tape attachment step 1, a detection step 2, a filling step 3, and a cutting step 4. Note that the detection step 2 may be omitted.

[0020] <Tape attachment step 1> FIG. 4 is a perspective view showing a state of the tape sticking step 1 shown in FIG. 3. FIG. 5 is a side view showing a state after the tape sticking step 1 shown in FIG. 3 in a partial cross section. The tape sticking step 1 is a step of sticking a tape 21 (dicing tape) larger than the outer diameter of the workpiece 10 on the front surface 12 side or the back surface 13 side of the workpiece 10. In the tape sticking step 1 of the embodiment, the tape 21 is stuck on the back surface side of the frame 20 and the back surface 13 side of the workpiece 10 with the workpiece 10 positioned inside the opening of the annular frame 20.

[0021] The frame 20 is an annular plate member formed of metal or resin and having an opening larger than the outer diameter of the workpiece 10. The tape 21 is in a sheet shape with an outer diameter larger than the opening of the frame 20, and is adhered to the back surface side of the frame 20 so as to cover the opening of the frame 20. The tape 21 may include, for example, a base material layer made of a synthetic resin having elasticity, and an adhesive layer laminated on the base material layer and made of a synthetic resin having elasticity and adhesiveness, or may be composed of a resin having thermoplasticity without having an adhesive layer.

[0022] The workpiece 10 is positioned at a predetermined position of the opening of the frame 20, and is fixed to the frame 20 and the tape 21 by sticking the front surface 12 or the back surface 13 side to the tape 21. At this time, a gap is generated between the chamfered portion 14 formed on the outer peripheral edge of the workpiece 10 and the tape 21 on the side surface (the back surface 13 in the embodiment) stuck to the tape 21 due to the roundness of the chamfered portion 14. The workpiece 10 is transported and processed while being supported by the annular frame 20 and the tape 21.

[0023] <Processing apparatus 100> Here, a configuration example of the processing apparatus 100 according to the embodiment of the present invention will be described. FIG. 6 is a perspective view showing a configuration example of the processing apparatus 100 according to the embodiment. The processing apparatus 100 is a cutting apparatus that performs cutting processing on the workpiece 10. In the processing method of the workpiece 10, the processing apparatus 100 performs a detection step 2, a filling step 3, and a cutting step 4.

[0024] The processing device 100 includes a holding table 110, a cutting unit 120, a detection unit 130, an X-axis moving unit 141, a Y-axis moving unit 142, a Z-axis moving unit 143, a conveying unit 150, a cassette mounting table 155, and a filling member supply unit 160. As shown in FIG. 6, the processing device 100 is a so-called facing dual-type processing device (cutting device) having two sets of cutting units 120, that is, a two-spindle dicing saw.

[0025] The holding table 110 holds the disk-shaped workpiece 10 with the tape 21 attached thereto on the holding surface 111 via the tape 21. The holding table 110 includes, for example, a disk-shaped frame body in which a recess is formed and a disk-shaped suction portion fitted into the recess. The suction portion of the holding table 110 is formed of a porous ceramic or the like having a large number of porous holes and is connected to a vacuum suction source (not shown) via a vacuum suction path (not shown). The upper surface of the suction portion of the holding table 110 is a holding surface 111 on which the workpiece 10 is placed and the placed workpiece 10 is sucked and held by the negative pressure introduced from the vacuum suction source. The holding table 110 is provided so as to be movable in the X-axis direction parallel to the horizontal direction by the X-axis moving unit 141. The holding table 110 is provided so as to be rotatable about the Z-axis parallel to the vertical direction and orthogonal to the XY plane by a rotation drive source (not shown).

[0026] The cutting unit 120 is a processing means for performing cutting processing on the workpiece 10 held by the holding table 110. The cutting unit 120 includes a cutting blade 121, a spindle 122 to which the cutting blade 121 is rotatably attached, and a cutting fluid supply unit for supplying cutting fluid to the cutting blade 121 and the machining point. The cutting blade 121 cuts the workpiece 10 held by the holding table 110.

[0027] The spindle 122 is rotatably provided around an axis parallel to the horizontal direction and parallel to the Y-axis direction orthogonal to the X-axis direction, and supports a cutting blade 121 attached to the tip of the spindle 122 so as to be rotatable around an axis parallel to the Y-axis direction. The cutting unit 120 is movably provided in the Y-axis direction and the Z-axis direction by a Y-axis moving unit 142 and a Z-axis moving unit 143, respectively.

[0028] The cutting unit 120 moves along the X-axis direction, which is the machining feed direction, relative to the workpiece 10 on the holding table 110 by the X-axis moving unit 141, and the cutting blade 121 to which a rotational operation around an axis parallel to the Y-axis direction is added by the spindle 122 cuts the workpiece 10 along, for example, a division planned line 15.

[0029] In the embodiment, the detection unit 130 is an imaging unit including an imaging element that images the workpiece 10 held on the holding table 110. The imaging element includes, for example, a CCD imaging element or a CMOS imaging element. In the embodiment, the detection unit 130 is fixed adjacent to the cutting unit 120 and moves integrally with the cutting unit 120.

[0030] The detection unit 130 images the surface 12 of the workpiece 10 held on the holding table 110 to obtain an image for performing alignment for aligning the workpiece 10 and the cutting unit 120, and outputs the obtained image to the control unit of the processing apparatus 100. The detection unit 130 detects a plurality of division planned lines 15 set on the workpiece 10 held on the holding table 110, and also detects a region that will become an end material chip 18 (see FIG. 8 described later), which is an end material of the device chip 17, in the outer peripheral region of the workpiece 10.

[0031] The X-axis moving unit 141, the Y-axis moving unit 142, and the Z-axis moving unit 143 are moving means for relatively moving the holding table 110, the cutting unit 120, and the detection unit 130 in the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively. In the embodiment, the X-axis moving unit 141 relatively moves the holding table 110 along the X-axis direction with respect to the cutting unit 120 and the detection unit 130. The X-axis moving unit 141 moves the holding table 110 between the loading / unloading area where the workpiece 10 is loaded / unloaded onto / from the holding table 110, the supply area where the filling member 30 is supplied by the filling member supply unit 160, and the processing area where the cutting is performed by the cutting unit 120.

[0032] In the embodiment, the Y-axis moving unit 142 and the Z-axis moving unit 143 relatively move the cutting unit 120 and the detection unit 130 along the Y-axis direction and the Z-axis direction with respect to the holding table 110, respectively. The X-axis moving unit 141, the Y-axis moving unit 142, and the Z-axis moving unit 143 are all known ball screw mechanisms having a motor, a ball screw, and a guide.

[0033] In the embodiment, the transfer unit 150 includes, for example, a pair of rails 151, a first transfer arm and a second transfer arm (not shown). The first transfer arm transfers the workpiece 10 between the inside of the cassette 156 placed on the cassette mounting table 155 and on the pair of rails 151. The second transfer arm transfers the workpiece 10 between the pair of rails 151 and the holding table 110. The pair of rails 151 can approach or separate while maintaining a parallel state to each other, and the workpiece 10 can be held via the frame 20 between the pair of rails 151.

[0034] The cassette mounting table 155 is a mounting table for mounting the cassette 156 which is a container for accommodating a plurality of workpieces 10, and raises and lowers the mounted cassette 156 in the Z-axis direction.

[0035] The filling member supply unit 160 is a unit that fills the chamfered portion 14 formed on the outer peripheral edge of the workpiece 10 held on the holding table 110 via the tape 21 and the gap between the tape 21 with the filling member 30. The filling member supply unit 160 includes a supply source that stores the filling member 30, a nozzle that discharges the filling member 30 in a predetermined direction, a flow path and a delivery pump that supply the filling member 30 from the supply source toward the opening of the nozzle, and the like. The filling member supply unit 160 may be configured to be movable between a supply position where the nozzle is positioned on the workpiece 10 held on the holding table 110 and a non-supply position where it retracts.

[0036] The filling member 30 is a member that is liquid during supply and hardens after being filled in the gap between the chamfered portion 14 and the tape 21, and includes, for example, a hot melt adhesive or a liquid resin such as a UV curable resin. The filling member 30 may contain abrasive grains. When the filling member 30 is a UV curable resin, the processing apparatus 100 may be provided with a UV irradiation unit that irradiates the supplied filling member 30 with UV. The UV irradiation unit is provided, for example, on the holding table 110 having the holding surface 111 as a transparent member such as glass, and the light source is disposed below the holding surface 111.

[0037] <Detection step 2> FIG. 7 is a side view showing a state of the detection step 2 shown in FIG. 3 in a partial cross section. FIG. 8 is a plan view of the workpiece 10 for explaining the detection step 2 shown in FIG. 3. The detection step 2 is carried out before the filling step 3. The detection step 2 is a step of detecting a region that becomes the end chip 18, which is an end material of the device chip 17 formed in the cutting step 4 described later.

[0038] In the tape attachment step 1, the cassette 156 containing the workpiece 10 to which the tape 21 is attached is carried into the cassette mounting table 155 of the processing apparatus 100. The workpiece 10 is taken out one by one from the cassette 156 by the transfer unit 150 and held on the holding table 110 via the tape 21. The workpiece 10 held on the holding table 110 is moved by the X-axis movement unit 141 under the imaging area of the detection unit 130.

[0039] As shown in FIG. 7, in the detection step 2, the surface 12 side of the workpiece 10 is imaged by the detection unit 130. From the captured image, a plurality of planned division lines 15 set on the workpiece 10 are detected by image recognition or the like. Also, in the detection step 2, an area to become the end material chip 18 is detected from the outer peripheral edge of the workpiece 10 and the plurality of planned division lines 15.

[0040] As shown in FIG. 8, the area to become the end material chip 18 is an outer peripheral area that does not have the device 16 and becomes the end material when the workpiece 10 is cut along the planned division line 15 in the subsequent cutting step 4 and separated into individual device chips 17. In particular, it shows a region smaller than a predetermined area, such as a substantially triangular shape or a substantially trapezoidal shape having a curved side. Here, the predetermined area indicates an area of 70% or less with respect to the area of the regular device chip 17. Practically, for example, an area where the intersection of the planned division lines 15 exists within a predetermined distance (for example, 1 mm) from the outer peripheral edge of the workpiece 10 may be used as the end material chip 18. In other words, the area to become the end material chip 18 is an area that may peel off from the tape 21 and scatter during cutting.

[0041] <Filling step 3> FIG. 9 is a side view showing a partial cross-section of a state of the filling step 3 shown in FIG. 3. FIG. 10 is a side view showing a partial cross-section of the state after the filling step 3 shown in FIG. 3. The filling step 3 is a step of filling the filling member 30 into the gap between the chamfered portion 14 formed on the outer peripheral edge of the workpiece 10 and the tape 21.

[0042] In the filling step 3, the workpiece 10 held on the holding table 110 via the tape 21 is moved by the X-axis moving unit 141 to the supply area of the filling member supply unit 160. As shown in FIG. 9, in the filling step 3, the tip of the nozzle of the filling member supply unit 160 is directed toward the gap between the chamfered portion 14 and the tape 21, and while supplying the filling member 30, the holding table 110 is rotated around the axis to fill the gap between the chamfered portion 14 and the tape 21 with the filling member 30.

[0043] When the detection step 2 is performed, in the filling step 3, the filling member 30 is intermittently supplied from the filling member supply unit 160, and the filling member 30 is filled only in the region that becomes the end chip 18 detected in the detection step 2. When the detection step 2 is omitted, in the filling step 3, the filling member 30 is continuously supplied from the filling member supply unit 160, and the filling member 30 is filled along the entire circumference of the outer peripheral edge of the workpiece 10. After the supplied filling member 30 is cured, the cutting step 4 is performed.

[0044] <Cutting Step 4> FIG. 11 is a perspective view showing a state of the cutting step 4 shown in FIG. 3. The cutting step 4 is performed after the filling step 3. The cutting step 4 is a step of cutting the workpiece 10 along the division planned line 15 and dividing the workpiece 10 into individual device chips 17.

[0045] In the cutting step 4, first, the workpiece 10 held on the holding table 110 via the tape 21 is moved by the X-axis moving unit 141 to the processing area by the cutting unit 120. The detection unit 130 images the workpiece 10 to detect the division planned line 15. When the division planned line 15 is detected, an alignment for aligning the division planned line 15 of the workpiece 10 and the cutting blade 121 is performed.

[0046] In the cutting step 4, next, the supply of the cutting fluid is started toward the machining point by the cutting blade 121, and the rotation of the spindle 122 is started. Next, while the holding table 110 is machined and fed in the X-axis direction by the X-axis moving unit 141, the cutting unit 120 is cut into a predetermined depth by the Z-axis moving unit 143 until the cutting edge of the cutting blade 121 reaches the tape 21. Thereby, the cutting groove 19 extending over the entire thickness direction of the workpiece 10 is formed. When the workpiece 10 is divided along one dividing line 15, the indexing feed is performed in the Y-axis direction so that the cutting blade 121 is positioned on the adjacent dividing line 15, and the workpiece 10 is similarly divided along the dividing line 15.

[0047] Thus, in the cutting step 4, the workpiece 10 held on the holding table 110 and the cutting blade 121 are relatively moved, and the workpiece 10 is cut along all the dividing lines 15, thereby fragmenting the workpiece 10 into the device chips 17. At this time, the filling member 30 suppresses the intrusion of the cutting water to the back surface 13 side, and the end chip 18 remains adhered to the tape 21. Further, when the filling member 3 has abrasive grains, the grinding stone of the cutting edge of the cutting blade 121 can be highlighted when the cutting blade 121 cuts the filling member 30.

[0048] As described above, in the machining method and the machining apparatus 100 for the workpiece 10 of the embodiment, the filling member 30 is filled in the gap between the chamfered portion 14 formed on the outer peripheral edge of the workpiece 10 and the tape 21, and the cutting process is performed in this state. Thereby, it is possible to suppress the cutting water from entering the gap and the end chip 18 from peeling off and scattering, and there is an effect that the risk of damage to the device 16 can be reduced.

[0049] When the filling member 30 is filled over the entire circumference of the workpiece 10, the effect of suppressing the intrusion of the cutting water can be improved. On the other hand, when the detection step 2 is performed and the filling member 30 is filled only in the region where the peeling and scattering of the end chip 18 are likely to occur, the filling member 30 can be saved.

[0050] Note that the present invention is not limited to the above-described embodiments. That is, various modifications can be made and implemented without departing from the gist of the present invention.

[0051] For example, in the detection step 2, it is not limited to the method of recognizing the end material chip 18 by image processing or the like as in the embodiment, and the end material chip 18 may be recognized from the size of the workpiece 10, the size of the device chip 17, the position of the orientation flat or notch indicating the crystal orientation, etc.

[0052] Further, the detection unit 130 may be arranged adjacent to the filling member supply unit 160. In this case, it is provided separately from the imaging unit for aligning the workpiece 10 and the cutting unit 120. Also, in the filling step 3, after being conveyed to the supply area and before starting the supply of the filling member 30, the outer peripheral edge of the workpiece 10 may be detected and aligned with the filling position. When the detection unit 130 is arranged adjacent to the filling member supply unit 160, it is conveyed from the cassette 156 to the supply area, the detection step 2 and the filling step 3 are carried out, then conveyed to the processing area, and aligned using an imaging unit different from the detection unit 130 to carry out the cutting step 4. Therefore, the moving distances of the holding table 110 and the workpiece 10 can be shortened.

Explanation of Reference Numerals

[0053] 10 Workpiece 11 Substrate 12 Front surface 13 Back surface 14 Chamfered portion 15 Predetermined dividing line 16 Device 17 Device chip 18 End material chip 19 Cutting groove 20 Frame 21 Tape 30 Filling member 100 Processing device (cutting device) 110 Holding table 120 Cutting unit 121 Cutting blade 130 Detection unit 160 Filling member supply unit

Claims

1. A method for processing a workpiece, which is a disk-shaped workpiece with a chamfered portion formed along its outer peripheral edge and a plurality of planned division lines set thereon, and which is divided along the planned division lines into individual device chips, comprising: a tape attaching step of attaching a tape larger than the outer diameter of the workpiece to the front side or the back side of the workpiece; a filling step of filling a filling member into the gap between the chamfered portion formed on the outer peripheral edge of the workpiece and the tape; a cutting step of relatively moving the workpiece and a cutting blade after the filling step and cutting the workpiece along the planned division line to divide the workpiece into individual device chips; comprising a method for processing a workpiece, characterized in that.

2. Before performing the filling step, further comprising a detecting step of detecting a region that becomes an end chip, which is an end material of the device chip formed in the cutting step; In the filling step, the filling member is filled into the region that becomes the end chip detected in the detecting step. The method for processing a workpiece according to claim 1, characterized in that.

3. A processing apparatus, comprising: a holding table for holding a disk-shaped workpiece with a chamfered portion formed along its outer peripheral edge and a tape larger than the outer diameter of the workpiece attached to the front side or the back side thereof, via the tape; processing means having a cutting blade for performing cutting on the workpiece held by the holding table; moving means for relatively moving the holding table and the processing means; comprising further comprising a filling member supply unit for filling a filling member into the gap between the chamfered portion formed on the outer peripheral edge of the workpiece and the tape. A processing apparatus, characterized in that.

4. Further comprising a detecting unit for detecting a plurality of planned division lines set on the workpiece for dividing the workpiece held by the holding table into individual device chips, and a region that becomes an end chip, which is an end material of the device chip, in the outer peripheral region of the workpiece. The processing apparatus according to claim 3, characterized in that.

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