Processing method

Abstract

The present application provides a processing method capable of efficiently processing two or more workpieces having different processing residual amounts. The processing method includes the following steps: a step difference forming step of forming a step difference corresponding to the processing residual amount on the upper surface of a substrate supporting the two or more workpieces; a workpiece arrangement step of arranging the workpieces on the upper surface of the substrate having the step difference on each plane where the step difference is formed; a substrate holding step of holding the substrate in the holding surface of the holding unit with the step difference direction of the substrate facing the X direction; a positioning step of positioning the disc grinder at a desired Y position by the Y direction feeding unit and at a desired Z position by the Z direction feeding unit; and a processing step of making the disc grinder act on the two or more workpieces by the X direction feeding unit to implement processing.

Description

Technical Field

[0001] The present invention relates to a processing method for processing two or more workpieces having different processing residual amounts. Background Art

[0002] The wafer is divided by predetermined dividing lines and devices such as ICs and LSIs are formed on the front side. After the back side of the wafer is ground to the desired thickness by a grinding device, it is divided into individual device chips by a cutting device and used in electronic devices such as mobile phones and personal computers.

[0003] In addition, in recent years, a process has been carried out in which relatively thick device chips are ground to a desired thinness with high precision (for example, refer to Patent Document 1). In order to find the appropriate thickness of the device chip, the device chip is processed into thicknesses of 20 μm, 50 μm, and 100 μm, for example, and the performance of the device chips of each thickness, such as drop strength, heat resistance, and heat release, is verified.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2001-351890

[0005] However, in order to form device chips of varying thicknesses as described above, when using a disc grinder to thin the front surface of each device chip, the disc grinder's machining allowance (= target thickness) must be varied for each device chip with a different target thickness, resulting in poor productivity. Furthermore, when verifying the appropriate penetration depth by half-cutting the wafer along the intended dividing line, the disc grinder's machining allowance must be varied for each test wafer with a different penetration depth, resulting in the same problem as described above. Summary of the Invention

[0006] The present invention has been made in view of the above-mentioned circumstances, and a main technical object of the present invention is to provide a machining method capable of efficiently machining two or more workpieces having different machining residual amounts.

[0007] To solve the above-described main technical problem, according to the present application, there is provided a processing method of processing two or more workpieces having different processing residual amounts in a Z direction using a processing apparatus having a holding unit having a holding surface that holds the workpieces, a processing unit having a rotary shaft extending in a Y direction and a disk grinder that processes the workpieces held by the holding unit, an X-direction feeding unit that relatively feeds the holding unit and the processing unit in an X direction, a Y-direction feeding unit that relatively indexes the holding unit and the processing unit in the Y direction, and a Z-direction feeding unit that relatively feeds the holding unit and the processing unit in a Z direction perpendicular to the holding surface, wherein the processing method includes a step of forming a step difference corresponding to the processing residual amount on an upper surface of a substrate that supports the two or more workpieces, a step of arranging the workpieces on the upper surface of the substrate on which the step difference is formed on each plane on which the step difference is formed, a step of holding the substrate on the holding surface of the holding unit with the step difference direction of the substrate facing the X direction, a step of positioning the disk grinder at a desired Y position by the Y-direction feeding unit and at a desired Z position by the Z-direction feeding unit, and a processing step of processing the two or more workpieces by the X-direction feeding unit with the disk grinder acting on the workpieces.

[0008] The processing method of the present application processes two or more workpieces having different processing residual amounts in the Z direction using a processing apparatus having a holding unit having a holding surface that holds the workpieces, a processing unit having a disc grinder that processes the workpieces held by the holding unit mounted on a rotating shaft extending in the Y direction, an X-direction feed unit that relatively feeds the holding unit and the processing unit in the X direction, a Y-direction feed unit that relatively indexes the holding unit and the processing unit in the Y direction, and a Z-direction feed unit that relatively feeds the holding unit and the processing unit in the Z direction perpendicular to the holding surface, wherein the processing method includes a step of forming a step difference corresponding to the processing residual amount on the upper surface of a substrate that supports the two or more workpieces, a workpiece arrangement step of arranging the workpieces on the upper surface of the substrate on which the step difference is formed on each plane on which the step difference is formed, a substrate holding step of holding the substrate on the holding surface of the holding unit with the step difference direction of the substrate facing the X direction, a positioning step of positioning the disc grinder at a desired Y position by the Y-direction feed unit and at a desired Z position by the Z-direction feed unit, and a processing step of processing the two or more workpieces by the X-direction feed unit with the disc grinder acting on the workpieces, so that the depth of cut does not need to be changed for each of the plurality of workpieces, and productivity can be improved. In addition, productivity is also improved when manufacturing a test piece for verifying the appropriate depth of cut by performing a semi-cut on a separation line of a wafer. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a perspective view of a cutting apparatus suitable for the processing method of the present application.

[0010] Figure 2 (a) of is a perspective view of a portion of a spindle unit arranged in the cutting apparatus, Figure 1 Figure 2 (b) of is a perspective view of the spindle unit shown in (a) of assembled. Figure 2

[0011] Figure 3 is a perspective view showing an embodiment of a step difference forming step.

[0012] Figure 4 (a) of is a perspective view showing an embodiment of a workpiece arrangement step, Figure 4 (b) of is a perspective view showing Figure 4 (a) of is a side view of the substrate shown in (a).

[0013] ​​Figure 5 is a perspective view showing an embodiment of the substrate holding step.

[0014] Figure 6 is a perspective view showing an embodiment of the positioning step.

[0015] Figure 7 (a) of FIG. 10 is a side view showing an embodiment of the processing step, Figure 7 (b) of FIG. 10 is a perspective view of a plurality of silicon chips formed by the processing step.

[0016] Figure 8 is a perspective view showing an embodiment of the positioning step of the second embodiment.

[0017] Figure 9 (a) of FIG. 12 is a side view showing an embodiment of the processing step of the second embodiment, Figure 9 (b) of FIG. 12 is a perspective view of a plurality of silicon chips formed by the processing step of the second embodiment.

[0018] Reference Signs

[0019] 1: cutting device; 2: base; 3: X-direction feed unit; 31: pulse motor; 32: externally threaded rod; 4: chuck table mechanism; 41: X-direction moving base; 42: cylindrical member; 43: cover member; 44: chuck table; 45: suction chuck; 45a: holding surface; 5: support frame; 5a: front surface; 50: opening; 51: guide rail; 6: cutting unit; 61: Y-direction moving base; 612: guide rail; 62: Z-direction moving base; 63: spindle unit; 631: unit case; 632: rotating shaft; 632a: externally threaded portion; 632b: flange; 633: disc-shaped abrasive; 634: abrasive cover; 635: servo motor; 636: nut; 637: disc-shaped abrasive; 64: Y-direction feed unit; 64a: externally threaded rod; 64b: pulse motor; 65: Z-direction feed unit; 651: externally threaded rod; 652: pulse motor; 66: spindle unit support member; 661: mounting portion; 662: support portion; 10A, 10B, 10C: silicon chip; 12A, 12B, 12C: cutting groove; 20, 22: substrate; 20A, 22A: first region; 20B, 22B: second region; 20C, 22C: third region. DETAILED DESCRIPTION

[0020] Hereinafter, a first embodiment of the processing method of the present application will be described in detail with reference to the drawings.

[0021] In Figure 1 the cutting device 1 suitable for carrying out the processing method of the present embodiment is used. Figure 1The illustrated cutting apparatus 1 has a base 2 on which a chuck table mechanism 4 that holds a workpiece, a gate-shaped support frame 5, and a cutting unit 6 that functions as a machining unit that machines the workpiece are provided.

[0022] The illustrated chuck table mechanism 4 has a pair of rails 2A, 2A provided on the upper surface of the base 2 and extending parallel to each other in the X direction indicated by the arrow X. An X direction moving base 41 is provided on the pair of rails 2A, 2A. A pair of guide grooves 411, 411 formed on the X direction moving base 41 are engaged with the pair of rails 2A, 2A, whereby the X direction moving base 41 is configured to be movable in the X direction.

[0023] A cylindrical member 42 is provided on the X direction moving base 41, and a chuck table 44 that functions as a holding unit that holds the workpiece is provided on the upper end of the cylindrical member 42. The chuck table 44 has a suction chuck 45 that constitutes a holding surface 45a that holds the workpiece in the X direction and a Y direction perpendicular to the X direction and is formed of a member having air permeability. A communication path, not shown, formed in the inside of the cylindrical member 42 and a suction unit are connected to the suction chuck 45. A cover member 43 having a hole through which the chuck table 44 is inserted is provided on the upper end of the cylindrical member 42, and the cover member 43 covers the X direction moving base 41. The chuck table 44 is rotationally driven by a rotational drive unit, not shown, such as a pulse motor. By operating the suction unit, the holding surface 45a of the chuck table 44 can be provided with a suction negative pressure to suction and hold the substrate 20 that holds the workpiece.

[0024] The chuck table mechanism 4 has an X direction feed unit 3 for machining feed of the chuck table 41 in the X direction along the pair of rails 2A, 2A. The X direction feed unit 3 includes an externally threaded rod 32 provided parallel to the pair of rails 2A, 2A, one end of which is supported by a bearing portion 2B so as to be rotatable, and a pulse motor 31 coupled to the other end of the externally threaded rod 32 to rotationally drive or reversely drive the externally threaded rod 32. The X direction feed unit 3 thus configured is screwed with an internally threaded portion, not shown, formed on the lower surface side of the X direction moving base 41. Therefore, the X direction feed unit 3 is able to move the chuck table 44 provided on the X direction moving base 41 in the X direction along the pair of rails 2A, 2A by rotationally driving or reversely driving the externally threaded rod 32 by driving the pulse motor 31.

[0025] The cutting apparatus 1 of the illustrated embodiment has a portal-shaped support frame 5 disposed along a Y direction perpendicular to the X direction across the pair of rails 2A, 2A described above. The support frame 5 has an opening 50 that allows movement of a chuck table 44 that is disposed so as to be movable along the pair of rails 2A, 2A. Above a front surface 5a of the support frame 5, a cutting unit 6 is disposed together with the pair of rails 51, 51. The cutting unit 6 has a Y direction moving base 61, a Z axis direction moving base 62, and a spindle unit 63. The Y direction moving base 61 is provided on a back surface side with omitted guide grooves that engage with the pair of rails 51, 51 described above, and is configured to be movable in the Y direction along the pair of rails 51, 51 by engaging the guide grooves with the pair of rails 51, 51. In addition, on a front surface 61a of the Y direction moving base 61, a pair of rails 612, 612 are disposed in a direction (direction indicated by arrow Z) perpendicular to the holding surface 45a of the chuck table 44 described above. The Y direction moving base 61 thus configured is moved in the Y direction along the pair of rails 51, 51 by a Y direction feed unit 64. The Y direction feed unit 64 includes an external screw rod 641 that is disposed in parallel between the pair of rails 51, 51, one end of which is supported by the bearing portion 52 so as to be rotatable, and a pulse motor 642 that is coupled to the other end of the external screw rod 641 and drives the external screw rod 641 in the forward direction or in the reverse direction. The Y direction feed unit 64 thus configured causes the external screw rod 641 to be screwed with an omitted internal screw portion provided to the back surface of the Y direction moving base 61. Therefore, the Y direction feed unit 64 is able to move the Y direction moving base 61 in the Y direction along the pair of rails 51, 51 by driving the pulse motor 642 to drive the external screw rod 641 in the forward direction or in the reverse direction.

[0026] The Z-direction moving base 62 is provided with a pair of guide grooves 621 on the rear surface side that engage with the pair of rails 612 provided on the front surface 61a of the Y-direction moving base 61, and is configured to be able to move in the Z-direction that is the plunge feed direction along the rails 612 by engaging the guide grooves 621 with the pair of rails 612. The Z-direction moving base 62 configured in this way is moved in the Z-direction along the pair of rails 612 by the Z-direction feed unit 65 illustrated. The Z-direction feed unit 65 includes an externally threaded rod 651 that is disposed in parallel between the pair of rails 612, one end of which is supported by a bearing portion (not illustrated) so as to be rotatable, and a pulse motor 652 that is coupled to the other end of the externally threaded rod 651 and drives the externally threaded rod 651 in the forward direction or the reverse direction. The Z-direction feed unit 65 configured in this way is screwed to an internally threaded portion (not illustrated) formed on the rear surface of the Z-direction moving base 62 by the externally threaded rod 651. Therefore, the Z-direction feed unit 65 is able to move the Z-direction moving base 62 in the Z-direction along the pair of rails 612 by driving the pulse motor 652 to drive the externally threaded rod 651 in the forward direction or the reverse direction.

[0027] A spindle unit support member 66 for supporting the spindle unit 63 is attached to the front surface 62a of the Z-direction moving base 62. The spindle unit support member 66 is formed in a cross-sectional L shape, and includes an attachment portion 661 attached to the front surface 62a of the Z-direction moving base 62 and a support portion 662 extending horizontally at a right angle from the lower end of the attachment portion 661, and the unit housing 631 of the spindle unit 63 is attached to the lower surface of the support portion 662.

[0028] In the unit housing 631, the rotary shaft 632 extending in the Y-direction is rotatably supported. Further, a disc grinder 633 that performs machining on a workpiece is attached to the front end portion on the one end side of the rotary shaft 632. The thickness of the disc grinder 633 is formed to be about 2 mm, and the outer peripheral end surface is formed flat (see also Figure 2 ). A grinder cover 634 that covers the disc grinder 633 is attached to the front end portion of the unit housing 631. A servo motor 635 that rotatably drives the rotary shaft 632 is attached to the other end portion of the unit housing 631. As Figure 2 shown in (a) of FIG. 6 (the grinder cover 634 is omitted for ease of explanation), an externally threaded portion 632a and a flange 632b are formed on the front end of the rotary shaft 632 that is rotatably supported by the spindle unit 63, the front end portion of the rotary shaft 632 is inserted into an opening 633a of the disc grinder 633, and the internally threaded portion 636a of a nut 636 is fastened to the externally threaded portion 632a of the rotary shaft 632, whereby the front end portion of the rotary shaft 632 is fixed to the disc grinder 633. Figure 2As shown in (b), the disk-shaped abrasive 633 is held and fixed to the front end portion of the rotating shaft 632 by the flange 632b and the nut 636.

[0029] Returning to Figure 1 The cutting device 1 is provided with an omitted control unit. The X-direction feed unit 3, the Y-direction feed unit 64, and the Z-direction feed unit 65 described above are connected to the control unit, and the operations of the X-direction feed unit 3, the Y-direction feed unit 64, and the Z-direction feed unit 65 are controlled in accordance with an instruction signal from the control unit. In the cutting device 1, in addition to the above-described structure, a photographing unit or the like for detecting a cutting position is provided, but in the present embodiment, the photographing unit is omitted. Figure 1

[0030] By causing the X-direction feed unit 3 to operate, the chuck table 44 provided as a holding unit and the cutting unit 6 can be relatively fed in the X-direction. By causing the Y-direction feed unit 64 to operate, the chuck table 44 and the cutting unit 6 can be relatively indexed in the Y-direction. By causing the Z-direction feed unit 65 to operate, the chuck table 44 and the cutting unit 6 can be relatively fed in the Z-direction perpendicular to the holding surface 45a. Thus, the position of the disk-shaped abrasive 633 of the cutting unit 6 with respect to the workpiece held by the chuck table 44 can be positioned at a desired position.

[0031] The cutting device 1 of the present embodiment has substantially the above-described structure, and a machining method of machining two or more workpieces having different machining residual amounts in the Z-direction by the cutting device 1 will be described below.

[0032] When the machining method of the present embodiment is implemented, first, a step difference forming process of forming a step difference corresponding to the machining residual amount on the upper surface of a substrate 20 supporting two or more workpieces is implemented. More specifically, for example, a plate-shaped substrate 20 as shown in the upper portion of (a) is prepared. The substrate 20 of the present embodiment is, for example, a circular plate having a thickness of 500 μm and is formed of silicon (Si). In addition, the substrate 20 is provided with a plurality of through holes 20a for supporting the workpieces. Figure 3 Figure 3 ​​The substrate 20 shown is formed of a circular plate, but the present application is not limited to this, and can be a plate of another shape such as a quadrangle. If the substrate 20 described above is prepared, the substrate 20 is carried to a grinding device, not shown, and in three regions, i.e., the first region 20A, the second region 20B, and the third region 20C, divided by parallel dashed lines A, B on the upper surface 20a side, the central second region 20B is ground to a flat surface by 30 μm, for example, relative to the first region 20A on which no grinding process is performed, and the second region 20B is formed to be 30 μm thinner than the first region 20A. Further, the third region 20C adjacent to the second region 20B, divided by the dashed line B, is ground to a flat surface by 50 μm, for example, relative to the second region 20B, and the third region 20C is formed to be 80 μm thinner than the first region 20A. Thus, the substrate 20 having the two-step difference in thickness in the direction of the step difference shown by the arrow Rl (a direction perpendicular to the dashed line A, the dashed line B) is formed. Figure 3 The perspective view shown in the lower part of FIG. 9 can be understood as follows. Two step differences are formed in the upper surface 20a of the substrate 20, and thus the substrate 20 having the two-step difference in thickness in the direction of the step difference shown by the arrow Rl (a direction perpendicular to the dashed line A, the dashed line B) is formed.

[0033] Regarding the step difference forming process of the present application, the substrate 20 is not limited to being formed of silicon as described above, and can be formed of polyethylene terephthalate (PET), for example. Further, in the step difference forming process of the embodiment described above, the circular plate-shaped substrate 20 having a certain thickness (500 μm) is prepared, and the second region 20B and the third region 20C on the upper surface 20a are ground to be thinned, and thus the step difference described above is formed, but the present application is not limited to this, and for example, the circular plate-shaped substrate 20 having a thickness (420 μm) of the third region 20C shown in the lower part of FIG. 10 can be prepared, and the plate forming the first region 20A and the second region 20B can be overlapped and attached to the circular plate-shaped substrate, and thus the first region 20A, the second region 20B, and the third region 20C having the step difference described above can be formed, and thus the substrate 20 shown in the lower part of FIG. 10 can be formed. Figure 3 The perspective view shown in the lower part of FIG. 10 can be understood as follows. Two step differences are formed in the upper surface 20a of the substrate 20, and thus the substrate 20 having the two-step difference in thickness in the direction of the step difference shown by the arrow Rl (a direction perpendicular to the dashed line A, the dashed line B) is formed. Figure 3 The perspective view shown in the lower part of FIG. 10 can be understood as follows. Two step differences are formed in the upper surface 20a of the substrate 20, and thus the substrate 20 having the two-step difference in thickness in the direction of the step difference shown by the arrow Rl (a direction perpendicular to the dashed line A, the dashed line B) is formed.

[0034] If the step difference forming process described above is performed, as shown in FIG. 11, a workpiece provisioning process is performed in which a workpiece is provisioned on the upper surface 20a of the substrate 20 having the step difference, on each flat surface (the first region 20A to the third region 20C) in which the step difference is formed. The workpiece of the embodiment is, for example, a semiconductor wafer. Figure 4 The perspective view shown in the lower part of FIG. 10 can be understood as follows. Two step differences are formed in the upper surface 20a of the substrate 20, and thus the substrate 20 having the two-step difference in thickness in the direction of the step difference shown by the arrow Rl (a direction perpendicular to the dashed line A, the dashed line B) is formed. Figure 4Silicon chips 10A, 10B, and 10C are schematically shown in (a). Silicon chips 10A, 10B, and 10C have the same shape as the device chip, for example, a rectangular parallelepiped with a 5 mm square edge and a height of 300 μm when viewed from above. The dimensions of substrates 20 and 22, the step height, and the dimensions of silicon chips 10A to 10C shown in the figures are exaggerated for ease of explanation.

[0035] When the silicon chips 10A to 10C are prepared, the silicon chip 10A is placed on the plane of the first region 20A, the silicon chip 10B is placed on the plane of the second region 20B, and the silicon chip 10C is placed on the plane of the third region 20C on the upper surface 20a of the substrate 20, and they are fixed by sticking them with wax or the like. In addition, the silicon chips 10A to 10C are preferably as follows: Figure 4 As shown in (a), they are arranged in a straight line along the step direction R1. Figure 4 As can be understood from (b), the aforementioned step difference is formed on the upper surface 20a of the substrate 20, so the silicon chip 10B arranged in the second region 20B is arranged 30 μm lower than the silicon chip 10A arranged in the first region 20A. Furthermore, the silicon chip 10C arranged in the third region 20C is arranged 80 μm lower than the silicon chip 10A arranged in the first region 20A (50 μm lower than the silicon chip 10B).

[0036] After the above-mentioned workpiece placement step is completed, the substrate 20 is transported to the Figure 1 The cutting device 1 shown in FIG. 1 is used to implement the substrate holding process described below. At this time, the chuck table 44 is as shown in FIG. Figure 1 As shown in FIG. 1 , the substrate 20 is positioned at the position where the workpiece is carried in and out. Figure 5 As shown, the substrate 20 is placed on the holding surface 45a of the chuck table 44 with the step direction R1 facing the X direction. Then, a suction unit (not shown) is activated to apply negative suction pressure to the holding surface 45a, thereby sucking and holding the substrate 20 on the holding surface 45a.

[0037] Next, the Y-direction feed unit 64 and the Z-direction feed unit are operated to implement the positioning process described below. When implementing the positioning process, first, the Y-direction feed unit 64 is operated as shown in FIG. Figure 6The position of the spindle unit 63 of the cutting unit 6 is moved in the Y direction as shown, the disc grinder 633 of the cutting unit 6 is positioned at a desired initial position in the Y direction (for example, at a Y position coinciding with the Y coordinates of the near side edges 10a, 10b, 10c of the silicon wafers 10A to 10C), and the Z direction feed unit 65 is operated to move the spindle unit 63 in the Z direction to lower it, and is positioned at a desired initial position in the Z direction, more specifically, as shown in (a) of FIG. 6, the lower end of the disc grinder 633 is positioned at a Z position coinciding with the Z coordinates of the holding surface 45a of the chuck table 44 at a distance Hl. This Hl is 520 μm, which is 20 μm set as a machining residue amount remaining after the upper surface of the silicon wafer 10A is cut, plus the thickness of the first region 20A of the substrate 20, which is 500 μm. Also, in carrying out this positioning process, the chuck table 44 can be positioned at any position between the carry-in / out position shown in FIG. 5 and the machining position at which cutting is carried out. Figure 7 Figure 1 The position of the spindle unit 63 of the cutting unit 6 is moved in the Y direction as shown, the disc grinder 633 of the cutting unit 6 is positioned at a desired initial position in the Y direction (for example, at a Y position coinciding with the Y coordinates of the near side edges 10a, 10b, 10c of the silicon wafers 10A to 10C), and the Z direction feed unit 65 is operated to move the spindle unit 63 in the Z direction to lower it, and is positioned at a desired initial position in the Z direction, more specifically, as shown in (a) of FIG. 6, the lower end of the disc grinder 633 is positioned at a Z position coinciding with the Z coordinates of the holding surface 45a of the chuck table 44 at a distance Hl. This Hl is 520 μm, which is 20 μm set as a machining residue amount remaining after the upper surface of the silicon wafer 10A is cut, plus the thickness of the first region 20A of the substrate 20, which is 500 μm. Also, in carrying out this positioning process, the chuck table 44 can be positioned at any position between the carry-in / out position shown in FIG. 5 and the machining position at which cutting is carried out. Figure 1 The position of the spindle unit 63 of the cutting unit 6 is moved in the Y direction as shown, the disc grinder 633 of the cutting unit 6 is positioned at a desired initial position in the Y direction (for example, at a Y position coinciding with the Y coordinates of the near side edges 10a, 10b, 10c of the silicon wafers 10A to 10C), and the Z direction feed unit 65 is operated to move the spindle unit 63 in the Z direction to lower it, and is positioned at a desired initial position in the Z direction, more specifically, as shown in (a) of FIG. 6, the lower end of the disc grinder 633 is positioned at a Z position coinciding with the Z coordinates of the holding surface 45a of the chuck table 44 at a distance Hl. This Hl is 520 μm, which is 20 μm set as a machining residue amount remaining after the upper surface of the silicon wafer 10A is cut, plus the thickness of the first region 20A of the substrate 20, which is 500 μm. Also, in carrying out this positioning process, the chuck table 44 can be positioned at any position between the carry-in / out position shown in FIG. 5 and the machining position at which cutting is carried out.

[0038] Also, in carrying out the above-described positioning process, in the case where the positions of the silicon wafers 10A to 10C are not known, the alignment process is appropriately carried out. In the case where the alignment process is carried out, a photographing unit (not shown) provided integrally with the cutting unit 6 is used to photograph the silicon wafers 10A to 10C provided on the chuck table 20 from above, the position information of the silicon wafers 10A to 10C is detected and stored in the above-described control unit, and the above-described positioning process is carried out based on the position information.

[0039] If the above-described positioning process is carried out, the machining process is carried out in which the disc grinder 633 is brought into contact with the above-described silicon wafers 10A to 10C by the above-described X direction feed unit 3, and machining is carried out. More specifically, first, the servo motor 635 of the cutting unit 6 is operated to move the disc grinder 633 in the X direction, and the disc grinder 633 is moved to the position of the silicon wafer 10A to be machined. Figure 6 , Figure 7The disc grinder 633 is rotated in the direction indicated by the arrow R2 in (a). Next, the X-direction moving unit 3 is operated to move the chuck table 44 in the X-direction, and the disc grinder 633 is relatively moved in the direction indicated by the arrow R3, and a part of the edge 10a on the front surface of the silicon chip 10A provided on the first region 20A of the substrate 20 is cut by the disc grinder 633. As described above, the lower end of the disc grinder 633 is positioned at a position of a height Hl (=520 μm) from the holding surface 45a of the chuck table 44, and the silicon chip 10A is formed with a thickness of 300 μm. Therefore, the silicon chip 10A is cut by 280 μm from the upper surface by the disc grinder 633, and the machining allowance is 20 μm. Next, the X-direction moving unit 3 is further operated to move the chuck table 44 in the X-direction. Thus, a part of the edge 10b on the front surface of the silicon chip 10B provided on the second region 20B of the substrate 20 is cut by the disc grinder 633. As described above, the height of the front surface of the second region 20B is set to be 30 μm lower than that of the first region 20A, and therefore the machining allowance when the silicon chip 10B is cut by the disc grinder 633 is 50 μm, which is 30 μm more than that of the silicon chip 10A.

[0040] As described above, the width (one side) of the silicon chips 10A to 10C in plan view is 5 mm, and in contrast, the thickness of the circular plate abrasive 633 is 2 mm, and therefore in the above-described one-time cutting process, cutting is performed only in a range of 2 mm from the end in the Y direction of the silicon chips 10A to 10C. Thereafter, the X direction moving unit 3 and the Z direction feed unit 65 are caused to operate to position the chuck table 44 at the above-described carry-in / carry-out position or an arbitrary position on the carry-in / carry-out position side, and the circular plate abrasive 633 is positioned at a desired initial position in the Z direction in which the circular plate abrasive 633 was positioned in the above-described positioning process. Further, the Y direction feed unit 64 is caused to operate to index feed the position of the circular plate abrasive 633 of the cutting unit 6 by 1.95 mm in the Y direction. Then, the servo motor 635 is caused to operate to rotate the circular plate abrasive 633, and the X direction feed unit 3 is caused to operate in the same manner as described above to cause the circular plate abrasive 633 positioned at a position at a height Hl from the holding surface 45a of the chuck table 44 to relatively move in the direction indicated by the arrow R3 in (a) of FIG. 10, and cut the upper surfaces of the silicon chips 10A to 10C. Figure 7

[0041] As described above, the width (one side) of the silicon chips 10A to 10C in plan view is 5 mm, and in contrast, the thickness of the circular plate abrasive 633 is 2 mm, and therefore in the above-described one-time cutting process, cutting is performed only in a range of 2 mm from the end in the Y direction of the silicon chips 10A to 10C. Thereafter, the X direction moving unit 3 and the Z direction feed unit 65 are caused to operate to position the chuck table 44 at the above-described carry-in / carry-out position or an arbitrary position on the carry-in / carry-out position side, and the circular plate abrasive 633 is positioned at a desired initial position in the Z direction in which the circular plate abrasive 633 was positioned in the above-described positioning process. Further, the Y direction feed unit 64 is caused to operate to index feed the position of the circular plate abrasive 633 of the cutting unit 6 by 1.95 mm in the Y direction. Then, the servo motor 635 is caused to operate to rotate the circular plate abrasive 633, and the X direction feed unit 3 is caused to operate in the same manner as described above to cause the circular plate abrasive 633 positioned at a position at a height Hl from the holding surface 45a of the chuck table 44 to relatively move in the direction indicated by the arrow R3 in (a) of FIG. 10, and cut the upper surfaces of the silicon chips 10A to 10C. Figure 7

[0042] According to the above-described embodiment, when processing a plurality of silicon chips 10A to 10C provided with different thicknesses, i.e., different processing residual amounts, it is possible to improve productivity without changing the plunge feed amount of the circular plate abrasive 633 for each chip.

[0043] ​​In addition, in the first embodiment described above, the following example is shown: a plurality of steps are set on the substrate 20 in a manner that the processing residue in the Z direction is different, and the entire front surface of the silicon chip 10A to 10C is cut to form three silicon chips 10A to 10C with different thicknesses, but the present invention is not limited to this. For example, it is also effective when you want to verify the appropriate processing residue (cutting residue) amount during half-cutting. Regarding half-cutting, when cutting along the predetermined dividing line of the workpiece from the front to form a cutting groove, a portion of the lower surface side is left uncut. The second embodiment of the processing method of the present invention is described below. In addition, in the second embodiment described below, Figure 1 The cutting device 1 shown in FIG. 1 is provided with a cutting tool 633 instead of the above-mentioned disc grinding tool 633 at the front end of the rotating shaft 632 of the cutting unit 6. Figure 8 The illustrated thickness of the grinding disc 637 (cutting tool) is approximately 50 μm.

[0044] In the second embodiment, first, a circular plate-shaped substrate 22 having a uniform thickness (500 μm) is prepared as in the first embodiment, and the step forming process is performed in the same manner as in the first embodiment. Figure 8 As shown in FIG. 1 , through this step difference forming step, a step difference corresponding to the machining residual amount (cutting residual amount) when the workpiece is half-cut is formed on the upper surface of the substrate 22, thereby forming the first region 22A, the second region 22B, and the third region 22C. In addition, the step difference formed by the first region 22A and the second region 22B, and the step difference formed by the second region 22B and the third region 22C in this embodiment are different from those in the first embodiment described above, and are both set to 50 μm. The workpiece of this embodiment is as shown in FIG. Figure 8 As shown in the upper portion of the figure, rectangular parallelepiped silicon chips 10A-10C are of the same shape and size as the pre-processed silicon chips 10A-10C used in the first embodiment. The same workpiece placement step as in the first embodiment is performed on these silicon chips 10A-10C. Silicon chips 10A-10C are arranged in a straight line along the step direction R1 on the upper surface 22a of the substrate 22 having the step formed thereon, on the respective planes of the first to third regions 22A, 22C forming the step. Next, a substrate holding step is performed using the same steps as above, with the substrate 22 held on the holding surface 45a of the chuck table 44 with the step direction R1 oriented in the X direction.

[0045] Next, the positioning process is performed: the Y-direction feeding unit 64 positions the disc grinder 637 at the desired Y position, and the Z-direction feeding unit 65 positions the disc grinder 637 at the desired Z position. More specifically, the Y-direction feeding unit 64 is operated. Figure 8 As shown, the disc grinder 637 is moved in the Y direction and positioned at the Y position that matches the Y coordinate of the center of the silicon chips 10A to 10C in the Y direction, and the Z direction feed unit 65 is operated to move the spindle unit 63 in the Z direction and lower it to the desired position in the Z direction. More specifically, Figure 9 As shown in (a), the lower end of the disc grinder 637 is positioned at a Z position corresponding to a Z coordinate of H2 from the holding surface 45a of the chuck table 44. This H2 is 600 μm, which is obtained by adding 100 μm, which is set as the cutting residue remaining after cutting the silicon chip 10A in the X direction, to the thickness of the first region 22A of the substrate 22, that is, 500 μm. In addition, when implementing this positioning process, the chuck table 44 can be positioned from Figure 1 Any position between the shown carry-in and carry-out positions and the front side of the machining position where cutting is performed.

[0046] After the positioning process is completed, the processing process is performed: the X-direction feed unit 3 causes the disc grinder 637 to act on the silicon chips 10A to 10C to perform processing. More specifically, the servo motor 635 of the cutting unit 6 is first operated to move the disc grinder 637 in the direction of the X-direction feed unit 3. Figure 8 Then, the disc grinding tool 637 ( Figure 9 (as indicated by the double-dashed line in (a)), the X-direction feed unit 3 is operated to relatively move the circular grinding wheel 637, which is positioned at a height H2 from the holding surface 45a of the chuck table 44, in the direction indicated by arrow R4, thereby cutting the center of the silicon wafer 10A in the Y direction, which is arranged in the first region 22A of the substrate 22. As described above, the lower end of the circular grinding wheel 637 is positioned at a height H2 (=600 μm) from the holding surface 45a of the chuck table 44. As a result, a cutting groove 12A with a depth of 200 μm from the upper surface is formed in the silicon wafer 10A, and the residual cutting amount in the cutting groove 12A is 100 μm.

[0047] Next, the X-direction moving unit 3 is further operated to move the chuck table 44 in the X-direction. Thereby, the Y-direction center of the silicon chip 10B provided on the second region 22B of the substrate 22 is cut by the disk grinder 637. As described above, the front surface of the second region 22B is set to be 50 μm lower than the front surface of the first region 22A, and thus the cut groove 12B having a depth of 150 μm from the upper surface is formed by cutting the silicon chip 10B with the disk grinder 637. Thereby, the cut residue in the cut groove 12B is 50 μm more than the silicon chip 10A, and is 150 μm. Further, the X-direction moving unit 3 is operated to move the chuck table 44 in the X-direction, and the Y-direction center of the silicon chip 10C provided on the third region 22C of the substrate 22 is cut by the disk grinder 637 to form the cut groove 12C. As described above, the front surface of the third region 22C is set to be 100 μm lower than the first region 22A and 50 μm lower than the second region 22B. Thereby, the cut groove 12C having a depth of 100 μm from the upper surface is formed by cutting the silicon chip 10C with the disk grinder 637, and the cut residue in the cut groove 12C is 200 μm. By the above, the processing procedure of the second embodiment is completed.

[0048] According to the above-described second embodiment, the disk grinder 637 is applied to three processed objects (silicon chips 10A to 10C) by the X-direction moving unit 3 to perform processing, and thereby processing with different cut residues in the Z-direction is performed. Therefore, even in a case where it is desired to verify an appropriate cut residue (processing residue) when performing a half cut on a division intended line of a wafer, it is not necessary to change the cut-in depth to the plurality of processed objects (silicon chips 10A to 10C) by operating the Z-direction moving unit 65, and the productivity of a chip for verification is improved.

[0049] Further, in the above-described embodiments, three planes (first to third regions 20A to 20C, first to third regions 22A to 22C) on which three processed objects are provided are formed on the substrates 20, 22, and two step differences are formed, respectively, but the present application is not limited to this, and a plurality of planes corresponding to the number of processed objects provided on the substrates 20, 22 can be formed, and a step difference corresponding to a processing residue can be formed by each plane.

Claims

1. A processing method, using a processing device to process two or more workpieces having different processing residual amounts in the Z direction, The processing device has: a holding unit having a holding surface defined by an X direction and a Y direction perpendicular to the X direction for holding a workpiece; A machining unit having a disc grinding tool mounted on a rotation axis extending in the Y direction for machining a workpiece held by the holding unit; An X-direction feeding unit, which feeds the holding unit and the processing unit relative to each other in the X-direction; A Y-direction feeding unit, which performs indexing feeding of the holding unit and the processing unit relative to each other in the Y-direction; and A Z-direction feeding unit is configured to feed the holding unit and the machining unit relative to each other in a Z-direction perpendicular to the holding surface. in, The processing method includes the following steps: a step forming step of forming a step corresponding to a machining residual amount on an upper surface of a substrate supporting two or more workpieces; a workpiece arranging step of arranging the workpiece on each plane where the step difference is formed on the upper surface of the substrate; a substrate holding step of holding the substrate on a holding surface of the holding unit with the step direction of the substrate formed with the step toward the X direction; a positioning step of positioning the disc abrasive tool at a desired Y position by the Y-direction feeding unit and positioning the disc abrasive tool at a desired Z position by the Z-direction feeding unit; and In the processing step, the X-direction feeding unit causes the disc grinding wheel to act on two or more workpieces to perform processing.

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