How to use the board

Abstract

To simplify input of cutting conditions to a cutting device for an operator.SOLUTION: A cutting device has: a chuck table for holding a substrate; and a cutting unit which has a spindle and in which a cutting blade is attached to a tip of the spindle. In the cutting device, a substrate using method is used when the cutting blade cuts into a substrate held by the chuck table in a substrate thickness direction to detect a height position of the cutting blade based on a cutting depth. The substrate using method includes: a placement step in which the substrate is placed on the chuck table; and a recording step in which multiple grooves are formed at an outer periphery part of the substrate with the cutting blade to record information regarding cutting conditions set during cutting of the cutting blade in the substrate.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for using a substrate used when detecting the height position of a cutting blade. [Background technology]

[0002] Device chips are mounted on electronic devices such as mobile phones and personal computers. Device chips are manufactured by grinding and thinning the back side of a workpiece such as a semiconductor wafer on which devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integrations) are formed on the front side, and then dividing the workpiece into device units.

[0003] When dividing a workpiece, for example, the workpiece is cut by a cutting device equipped with a cutting blade. Before cutting with the cutting device, the origin position in the height direction of the cutting blade may be detected. One method for detecting the origin position is Chopper Cut Setup (CCS).

[0004] In the chopper cut setup, a cutting blade rotating at high speed around a spindle is lowered almost vertically while one side of a rectangular silicon substrate is held by suction on a rectangular sub-chuck table, whereby the lower end of the cutting blade cuts into the other side (i.e., the top surface) of the silicon substrate to form a groove (cut groove).

[0005] Then, based on the length of the cutting groove on the top surface of the silicon substrate and the radius of the cutting blade, the origin position in the height direction of the cutting blade when the lower end of the cutting blade contacts the top surface of the silicon substrate is calculated (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2002-59365 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, when performing chopper cut setup, the operator must input cutting conditions such as the distance between grooves (the so-called index amount), cutting position, and the number of cuttings made into the cutting device each time it is used, making the work complicated.

[0008] The present invention has been made in consideration of the above problems, and has an object to simplify input of cutting conditions to a cutting device for an operator. [Means for solving the problem]

[0009] According to one aspect of the present invention, there is provided a method of using a substrate in a cutting device having a chuck table for holding a substrate, and a cutting unit having a spindle and a cutting blade attached to the tip of the spindle, in which the cutting blade is cut into the substrate held by the chuck table in the thickness direction of the substrate and the height position of the cutting blade is detected based on the cutting depth, the method comprising: a loading step of loading the substrate on the chuck table; and a recording step of forming a plurality of grooves with the cutting blade on the outer periphery of the substrate and recording on the substrate information regarding the cutting conditions when cutting with the cutting blade.

[0010] Preferably, the method of using a substrate further comprises, after the recording step, a reading step of imaging the plurality of grooves formed on the substrate and reading information relating to the cutting conditions from the image of the plurality of grooves.

[0011] In addition, preferably, the information regarding the cutting conditions is determined according to the length of each groove and the arrangement of the multiple grooves, and in the reading step, information corresponding to the length of each groove and the arrangement of the multiple grooves is read from the image.

[0012] In addition, preferably, the method of using the substrate further comprises, after the reading step, a chopper cut setup step of cutting the cutting blade in the thickness direction of the substrate to form a groove for measuring the cutting depth of the cutting blade, and, after the chopper cut setup step, an additional recording step of forming a plurality of grooves with the cutting blade on the outer periphery of the substrate to record updated information regarding the cutting conditions, wherein the updated information includes at least one of the number of grooves for measuring the cutting depth formed in the substrate and the position of the groove for measuring the cutting depth finally cut by the cutting blade.

[0013] Also, preferably, the information on the cutting conditions includes a distance between grooves for measuring the cutting depth of the cutting blade. Effect of the Invention

[0014] In a method of using a substrate according to one aspect of the present invention, a plurality of grooves are formed on the outer periphery of the substrate with a cutting blade, and information regarding the cutting conditions when the cutting blade cuts into the substrate is recorded on the substrate (recording step).

[0015] If the cutting device converts the images of the multiple grooves into information about the cutting conditions according to a predetermined rule, the operator does not have to input the cutting conditions, which simplifies the input of the cutting conditions to the cutting device. [Brief description of the drawings]

[0016] [Figure 1] FIG. [Diagram 2] FIG. 1 is a flow diagram of a method for using a silicon substrate. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. 2 is a top view of a silicon substrate. [Figure 6] FIG. [Figure 7] FIG. 2 is a side view showing the CCS process. [Figure 8] FIG. 2 is a top view of the silicon substrate after the CCS process. [Figure 9] FIG. 13 is a top view of the silicon substrate after an additional recording process. [Figure 10] FIG. 11 is a top view of a substrate according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] An embodiment according to one aspect of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a perspective view of a cutting device 2. In Fig. 1, some of the components of the cutting device 2 are shown in functional blocks. In the following description, the X-axis direction (machining feed direction), the Y-axis direction (indexing feed direction), and the Z-axis direction (height direction) are mutually orthogonal directions.

[0018] An operation panel 4 functioning as an input device is provided on the front side (one side in the Y-axis direction) of the cutting device 2. For example, an operator can set processing conditions and the like for the cutting device 2 via the operation panel 4. A monitor 6 functioning as a display device is provided on the side surface on the front side of the cutting device 2.

[0019] The monitor 6 displays a guide screen for guiding the operator in operation, images captured by a microscope camera unit (imaging unit) 26 (described later), and the like. The monitor 6 may be a touch panel that functions as an input device and a display device. In this case, the operation panel 4 may be omitted.

[0020] A disk-shaped wafer 11 (see FIG. 4) made of a semiconductor material such as silicon is cut by the cutting device 2. A circular resin tape 25 (dicing tape, see FIG. 10) is attached to the back surface 11b of the wafer 11 at its center.

[0021] One surface of a metal annular frame 27 (see FIG. 10) having an opening with a diameter larger than that of the wafer 11 is attached to the outer periphery of the dicing tape. The wafer 11, the dicing tape, and the annular frame form a wafer unit.

[0022] A plurality of (e.g., 25) wafer units are housed in one cassette 8, and the cassette 8 is placed on a cassette table 10 provided at a corner on the front side of the cutting device 2. An elevator 12 capable of moving the cassette table 10 up and down is connected to the bottom of the cassette table 10.

[0023] A push-pull arm 14 that can access the cassette 8 is provided behind the cassette table 10 (the other side in the Y-axis direction). A pair of guide rails 16 that adjust the position of the wafer unit in the X-axis direction are provided on both sides of the movement path of the push-pull arm 14.

[0024] A first transport unit 18 that can access the pair of guide rails 16 is provided near the pair of guide rails 16. The first transport unit 18 transports a wafer unit from the pair of guide rails 16 to a disk-shaped chuck table 20 that is located in the load / unload area A1.

[0025] The chuck table 20 has a disk-shaped metal frame and a disk-shaped porous plate disposed in the center of the frame. A negative pressure is transmitted to the porous plate from a suction source (not shown) such as an ejector. The upper surface of the porous plate and the upper surface of the frame are substantially flush with each other, forming a holding surface 20a that holds the wafer unit (wafer 11) by suction.

[0026] A plurality of clamp units 20b for fixing the frame 27 are provided on the outer periphery of the chuck table 20. In addition, a rotation drive source (not shown) such as a motor that rotates the chuck table 20 around a predetermined rotation axis is connected to the lower part of the chuck table 20.

[0027] A rectangular table cover 22 is provided between the rotary drive source and the chuck table 20. On the upper surface of the table cover 22, a sub-chuck table 24 made of metal and shaped like a rectangular plate is provided.

[0028] The height of the holding surface 24a of the sub-chuck table 24 is set to be approximately the same as the height of the holding surface 20a. A rectangular annular groove is formed in the holding surface 24a, and a cross-shaped groove connected to the rectangular annular groove is formed closer to the center of the holding surface 24a than the rectangular annular groove.

[0029] A negative pressure is transmitted to each groove from a suction source (not shown) such as an ejector. The holding surface 24a suctions and holds a rectangular plate-shaped silicon substrate (substrate) 13 made of single crystal silicon by this negative pressure. The silicon substrate 13 is used when detecting the height position of a cutting blade 34, which will be described later.

[0030] The silicon substrate 13 has one surface that is approximately the same size as the holding surface 24a. The silicon substrate 13 of this embodiment is a rectangular plate with long sides of 75 mm, short sides of 37.5 mm, and a thickness of approximately 0.8 mm to 1.0 mm.

[0031] An X-axis direction moving mechanism 22a is provided below the rotation drive source of the chuck table 20. The X-axis direction moving mechanism 22a moves the rotation drive source, the chuck table 20, the table cover 22, the sub-chuck table 24, etc., integrally along the X-axis direction.

[0032] 1, the general position of the X-axis direction moving mechanism 22a is indicated by an arrow, but the specific structure is omitted. The X-axis direction moving mechanism 22a has a pair of guide rails (not shown) arranged along the X-axis direction.

[0033] An X-axis direction moving table (not shown) is slidably connected on the pair of guide rails. A rotation drive source for the chuck table 20 is fixed to the upper surface of the X-axis direction moving table. A nut portion (not shown) is provided on the lower surface side of the X-axis direction moving table.

[0034] A ball screw (not shown) is rotatably connected to the nut portion. The ball screw is disposed between a pair of guide rails, and a stepping motor (not shown) is provided at one end of the ball screw. When the stepping motor is operated, the X-axis direction moving table moves along the X-axis direction.

[0035] The X-axis direction moving mechanism 22a moves the chuck table 20 between the load / unload area A1 and the cutting area A2. Furthermore, the X-axis direction moving mechanism 22a feeds the chuck table 20 at a predetermined processing feed speed in the cutting area A2.

[0036] A microscope camera unit 26 is provided above the movement path of the chuck table 20 so as to face the holding surface 20a or the holding surface 24a. The microscope camera unit 26 has a camera including a predetermined optical system and an imaging element such as a CCD image sensor or a CMOS image sensor.

[0037] A ball screw type Y-axis direction moving unit (not shown) is connected to the microscope camera unit 26. By adjusting the position of the microscope camera unit 26 in the Y-axis direction and adjusting the position of the chuck table 20 in the X-axis direction, an image of any area on the front surface 11a side of the wafer 11 located on the holding surface 20a is captured. The image captured by the microscope camera unit 26 is sent to a control unit 44, which will be described later.

[0038] Similarly, by adjusting the position of the microscope camera unit 26 in the Y-axis direction and adjusting the position of the sub-chuck table 24 in the X-axis direction, an image of an arbitrary area on the upper surface 13a side of the silicon substrate 13 located on the holding surface 24a is captured. The captured image is sent to the control unit 44.

[0039] A cutting unit 28 is provided above the cutting area A2. The cutting unit 28 will now be described with reference to Fig. 3. The cutting unit 28 has a cylindrical spindle housing 30 whose longitudinal direction is disposed along the Y-axis direction.

[0040] A part of a cylindrical spindle 32 is rotatably accommodated in the spindle housing 30. A rotary drive source (not shown) such as a motor is provided at the base end of the spindle 32, and a cutting blade 34 having an annular cutting edge is attached to the tip end of the spindle 32. When the rotary drive source is operated, the cutting blade 34 rotates at high speed in a predetermined direction R.

[0041] The upper part of the cutting blade 34 is covered with a blade cover 36. The blade cover 36 is provided with a nozzle unit 38 that supplies cutting water such as pure water to the cutting blade 34.

[0042] A ball screw type cutting feed mechanism (not shown) that moves the cutting unit 28 along the Z-axis direction is connected to the spindle housing 30. In addition, the cutting feed mechanism is moved along the Y-axis direction together with the cutting unit 28 by a ball screw type indexing feed mechanism (not shown).

[0043] 1, a description will now be given of other components of the cutting device 2. A second transport unit 40 and a spinner cleaning unit 42 are provided behind the load / unload area A1.

[0044] After cutting the wafer 11, the second transport unit 40 accesses the chuck table 20 arranged in the load / unload area A1, and transports the wafer 11 from the chuck table 20 in the load / unload area A1 to the spinner table of the spinner cleaning unit .

[0045] After being spin-cleaned and spin-dried in the spinner cleaning unit 42, the wafer 11 is transferred to the pair of guide rails 16 by the first transfer unit 18, and then loaded into the cassette 8 by the push-pull arm 14 or the like.

[0046] Each component of the cutting device 2 is controlled by a control unit 44. The control unit 44 in this embodiment is configured by a computer. The control unit 44 includes a processor (processing device) represented by a CPU (Central Processing Unit), a main storage device, and an auxiliary storage device.

[0047] The primary storage device includes a dynamic random access memory (DRAM), a static random access memory (SRAM), a read only memory (ROM), etc. The secondary storage device includes a flash memory, a hard disk drive, a solid state drive, etc.

[0048] The auxiliary storage device stores software including a predetermined program. The functions of the control unit 44 are realized by operating the processing device and the like in accordance with this software.

[0049] The control unit 44 includes an image processor 46 that processes the image sent from the microscope camera unit 26. The image processor 46 is, for example, a predetermined program stored in an auxiliary storage device. The image processor 46 identifies the lengths of the multiple grooves 15 (see FIG. 5) formed in a predetermined region on the upper surface 13a of the silicon substrate 13 based on the image of the upper surface 13a.

[0050] For example, the length of one pixel in an image is predetermined according to the shooting magnification, and the image processing unit 46 determines the length of each groove 15 by calculating the length of the groove 15 from the number of pixels corresponding to the groove 15.

[0051] The multiple grooves 15 are formed in part of the outer periphery of the upper surface 13a side of the silicon substrate 13 so as to be perpendicular to the linear edge of the silicon substrate 13. The multiple grooves 15 of this embodiment are formed in the vicinity of the corners of the silicon substrate 13, as shown in FIG.

[0052] In this embodiment, the grooves 15 are formed using the cutting blade 34, so that the grooves 15 have approximately the same width and a predetermined depth (e.g., 50 μm) that does not reach the lower surface 13b. However, the lengths of the grooves 15 are not necessarily the same.

[0053] The length of each groove 15 and the arrangement of the multiple grooves 15 are converted by the information conversion unit 48 into information 17 (see FIG. 6) regarding the cutting conditions when the cutting blade 34 cuts into the silicon substrate 13. The information conversion unit 48 is, for example, a predetermined program stored in an auxiliary storage device.

[0054] First, the numbers indicated by the length of groove 15 will be described with reference to Fig. 6. The first groove 15a from the left end of Fig. 6 indicates the reference length of the multiple grooves 15 excluding groove 15a (first rule). The length of the second groove 15b from the left end is converted into a number by information conversion unit 48 using the length of groove 15a as the reference.

[0055] In this embodiment, the length of groove 15a is 1 mm, and the length of groove 15b is 3 mm. In this case, the information conversion unit 48 converts groove 15a into the number "1" and converts groove 15b into the number "3."

[0056] Next, the arrangement of the plurality of grooves 15 will be described. The arrangement of the plurality of grooves 15 indicates predetermined information. For example, grooves 15a and 15b correspond to information 17a indicating the management number (e.g., product number or product lot number) of silicon substrate 13 (second rule).

[0057] The number "13" specified by the grooves 15a and 15b is linked one-to-one to the management number of the silicon substrate 13 by a table, a formula, or the like pre-stored in the auxiliary storage device. Therefore, the control unit 44 can read the management number of the silicon substrate 13 based on the images of the grooves 15a and 15b.

[0058] Regarding the interval between the grooves 15, the grooves 15a and 15b in this embodiment are spaced 0.5 mm apart in the long side direction of the silicon substrate 13. In contrast, the groove 15b is spaced 1 mm apart from the third groove 15c from the left end in Fig. 6. However, these numerical values ​​are merely examples and may be changed as appropriate.

[0059] The groove 15c corresponds to information 17b indicating the distance (so-called index amount) in the index feed direction between grooves 19 (see Figures 8 and 9) for measuring the cutting depth, which are formed by cutting the cutting blade 34 approximately vertically into the upper surface 13a of the silicon substrate 13 during chopper cut setup (Third rule).

[0060] The number indicated by the length of groove 15c is expressed in an (N+1)-ary system, where the number indicated by groove 15b is N (N: natural number). In this embodiment, since the number indicated by the length of groove 15b is 3, the number indicated by each length of groove 15c to groove 15f is expressed in a 4-ary system (=3+1).

[0061] In this embodiment, the length of the groove 15c is 1 mm, so the groove 15c represents the number "1" in base 4, which is the decimal number 1 (=4 0 The decimal numbers designated by the grooves 15c correspond to the intervals of the grooves 19 for measuring the cutting depth in a one-to-one correspondence according to a table, formula, or the like previously stored in an auxiliary storage device. Therefore, the control unit 44 can read the information 17b on the intervals of the grooves 19 based on the image of the grooves 15c.

[0062] In addition, by forming further grooves 15d, 15e, 15f, 15g, and 15h (see Figure 9) on the opposite side of groove 15c from grooves 15a and 15b, update information (information 17c and 17d) of silicon substrate 13 associated with use of silicon substrate 13 may be further recorded.

[0063] Grooves 15d, 15e, and 15f correspond to information 17c indicating the number of already formed grooves 19 for measuring cutting depth (fourth rule). In this embodiment, groove 15d has a length of 1 mm, groove 15e has a length of 3 mm, and groove 15f has a length of 2 mm, so grooves 15d, 15e, and 15 indicate the number "132" in base 4.

[0064] The number "132" in base 4 is 30 (=4 2 x1+4 1 ×3+4 0 The decimal numbers designated by the grooves 15d, 15e, 15f are converted into the number of grooves 19 formed in the silicon substrate 13 according to a table, formula, etc., previously stored in the auxiliary storage device. In this way, the control unit 44 can read the information 17c indicating the number of grooves 19 already formed, based on the image including the grooves 15d, 15e, 15f.

[0065] In this embodiment, the grooves 15d, 15e, and 15f are disposed at intervals of 0.5 mm in the long side direction of the silicon substrate 13. In contrast, the grooves 15c and 15d are spaced 1 mm apart in the same direction. However, these numerical values ​​are merely examples and may be changed as appropriate.

[0066] Grooves 15g and 15h correspond to information 17d indicating the position (two-dimensional coordinates) in upper surface 13a of silicon substrate 13 corresponding to position 19a of groove 19 last cut by cutting blade 34 (fifth rule).

[0067] The length of the groove 15g shown in FIG. 9 is 3 mm, so the groove 15g represents the number "3" in base 4. Also, the length of the groove 15h is 2 mm, so the groove 15h represents the number "2" in base 4. The number "3" in base 4 is converted into the decimal number 3 (=4 0 ×3), and the digit "2" in base 4 is 2 in decimal (=4 0 ×2).

[0068] The decimal numbers specified by grooves 15g and 15h are finally converted into the XY coordinates of groove 19 formed in silicon substrate 13 according to tables, formulas, etc. previously stored in an auxiliary storage device. For example, the decimal number specified by groove 15g corresponds to the X coordinate, and the decimal number specified by groove 15h corresponds to the Y coordinate.

[0069] In this embodiment, the grooves 15g and 15h are spaced apart by 0.5 mm in the long side direction of the silicon substrate 13. In contrast, the grooves 15f and 15g are spaced apart by 1 mm in the same direction. However, these numerical values ​​are merely examples and may be changed as appropriate.

[0070] When the update information indicated by grooves 15d to 15h is to be further updated, one or more additional grooves corresponding to the updated update information are formed at a corner other than the corner where grooves 15a to 15c are formed, without changing grooves 15d to 15h themselves.

[0071] For example, the additional grooves are formed at other corners in a clockwise direction according to the update order, starting from the corner where grooves 15a to 15c are formed. In this case, the latest information can be confirmed by capturing images of the corners of the silicon substrate 13 in a clockwise order with the microscope camera unit 26.

[0072] Next, a method of using the silicon substrate 13 according to the first embodiment will be described with reference to Figures 1 to 9. Figure 2 is a flow diagram of the method of using the silicon substrate 13.

[0073] 1, an operator places an unused silicon substrate 13 (i.e., a substrate on which the grooves 15 and 19 are not formed) on the sub-chuck table 24 (placement step S10). After the placement step S10, the silicon substrate 13 is suction-held by the holding surface 24a.

[0074] Then, the operator inputs information such as the control number of the silicon substrate 13, the distance (index amount) between the grooves 19 for measuring the cutting depth to be formed, and the area in which the multiple grooves 15 are to be formed through the operation panel 4 (input step S20).

[0075] Based on the information input in the input process S20, the control unit 44 controls the X-axis direction moving mechanism 22a, the microscope camera unit 26, the cutting unit 28, etc., to cut the cutting blade 34 into the outer periphery of the silicon substrate 13, and form grooves 15a, 15b, and 15c of predetermined depths (recording process S30).

[0076] 3 is a diagram showing the recording step S30. In the recording step S30, first, the microscope camera unit 26 captures an image of the front corner of the silicon substrate 13, and the position of the cutting blade 34 relative to the silicon substrate 13 in the Y-axis direction is adjusted.

[0077] Then, the lower end of the rotating cutting blade 34 is positioned at a predetermined cutting depth (for example, 50 μm) from the upper surface 13a outside the silicon substrate 13, and the sub-chuck table 24 is fed for processing by the X-axis direction moving mechanism 22a.

[0078] After the sub-chuck table 24 is fed for processing by a distance corresponding to the length of the groove 15a, the cutting unit 28 is indexed and fed by a distance corresponding to the interval between the grooves 15 to form a groove 15b in the same manner as the groove 15a. Furthermore, a groove 15c is formed.

[0079] In this manner, the information input in the input step S20 (corresponding to the information 17a, 17b) is recorded as the plurality of grooves 15a, 15b, 15c. After the recording step S30 is completed, the silicon substrate 13 on which the plurality of grooves 15a to 15c are formed is temporarily removed from the sub-chuck table 24 (removal step S40).

[0080] After the removal step S40, if chopper cut setup is not performed (NO in S50), the flow ends, but if chopper cut setup is performed (YES in S50), the flow proceeds to the reading step S60.

[0081] In the reading step S60, first, an operator places the silicon substrate 13 having the plurality of grooves 15a, 15b, and 15c formed therein on the sub-chuck table 24, and the lower surface 13b side of the silicon substrate 13 is suction-held by the holding surface 24a.

[0082] Then, from the images obtained by imaging the plurality of grooves 15a, 15b, and 15c with the microscope camera unit 26, information 17 relating to the cutting conditions is read in accordance with the above-mentioned predetermined first and third rules. At this time, the management number of the silicon substrate 13 is also read based on the second rule. Figure 4 is a diagram showing the reading step S60.

[0083] In this embodiment, after the cutting blade 34 records the information 17 on the cutting conditions using the grooves 15a, 15b, and 15c, the information 17 on the cutting conditions can be read based on an image of the grooves 15.

[0084] This allows the cutting device 2 to convert the images of the plurality of grooves 15a, 15b, 15c into information regarding the cutting conditions in accordance with a predetermined rule, thereby eliminating the need for the operator to input the cutting conditions.

[0085] This simplifies the input of cutting conditions to the cutting device 2. Furthermore, the operator's effort in inputting cutting conditions via the operation panel 4 is reduced, and input errors can be avoided.

[0086] Fig. 5 is a top view of the silicon substrate 13 during the reading step S60, and Fig. 6 is an enlarged view of the rectangular area B indicated by the dashed line in Fig. 5. The information 17a and 17b may be displayed on the monitor 6 together with information on the type of the cutting blade 34 attached to the spindle 32.

[0087] After the reading step S60, a chopper cut setup step (hereinafter, simply referred to as a CCS step) S70 is performed. Fig. 7 is a side view showing the CCS step S70, and Fig. 8 is a top view of the silicon substrate 13 after the CCS step S70.

[0088] In the CCS process S70, the cutting blade 34 is lowered along the Z-axis direction, and the lower end of the cutting blade 34 cuts into the silicon substrate 13 in the thickness direction. This forms a groove 19 on the upper surface 13a side of the silicon substrate 13, which does not reach the holding surface 24a.

[0089] Then, based on the length C of the groove 19 measured by the microscope camera unit 26 and the radius D of the cutting blade 34, the position in the Z-axis direction of the center of the cutting blade 34 when the lower end of the cutting blade 34 contacts the upper surface 13a is calculated.

[0090] Specifically, first, the radius D of the cutting blade 34 is calculated. To this end, the distance h between the center and the upper surface 13a is calculated from the difference between the position Z1 of the center of the cutting blade 34 in the Z-axis direction and the position Z2 of the upper surface 13a of the silicon substrate 13 in the Z-axis direction.

[0091] The distance h and the length C determine the radius D of the cutting blade 34 as follows: 2 +(C / 2) 2} 1 / 2 With the length C and radius D, the cutting depth E is D-{D 2 -(C / 2) 2} 1 / 2 From the above, the position of the cutting blade 34 in the Z-axis direction (origin position) when the lower end of the cutting blade 34 comes into contact with the upper surface 13a is calculated as Z1+E.

[0092] After the CCS step S70, grooves 15d, 15e, 15f corresponding to information 17c indicating the number of grooves 19 already formed, and grooves 15g, 15h corresponding to information 17d indicating the position 19a of the last formed groove 19 are recorded by the cutting blade 34 (additional recording step S80).

[0093] Fig. 9 shows the upper surface of the silicon substrate 13 after the additional recording step S80. Note that, for convenience of explanation, a plurality of grooves 19 are shown in Fig. 9, but the additional recording step S80 may be performed after one groove 19 is formed.

[0094] In the next reading step S60, the control unit 44 can automatically read the number of formed grooves 19 and the position of the last formed groove 19 from grooves 15d to 15h. This reduces the operator's effort in inputting the cutting conditions via the operation panel 4, and also prevents input errors.

[0095] Alternatively, either the number of grooves 19 already formed (information 17c) or the position 19a of the groove 19 last cut by the cutting blade 34 (information 17d) may be recorded on the silicon substrate 13.

[0096] For example, when the index amount (information 17b), the size of silicon substrate 13, and the order in which trenches 19 are formed are known, information 17d can be identified from information 17c, and conversely, information 17c can be identified from information 17d.

[0097] Furthermore, if the position 19a of the groove 19 where the cutting blade 34 last cut is known, the control unit 44 can automatically determine the position 19b (shown by a dashed line in FIG. 9) where the next groove 19 will be formed.

[0098] Incidentally, the grooves 15 other than the grooves 15a and 15b can also be expressed in any (N+1)-ary number system. However, in the case of binary number system (N=1), the number of grooves 15 arranged in parallel becomes relatively large according to the amount of information to be recorded.

[0099] Therefore, the lower limit of N (a natural number) is preferably 2 or more (i.e., ternary, quaternary, etc.). On the other hand, in order to increase the amount of information recorded in one groove 15, for example, hexadecimal (N=15) may be adopted.

[0100] However, since the size of the imaging field of the microscope camera unit 26 mounted on the cutting device 2 is usually about 5.1 mm in the Y-axis direction and 4.8 mm in the X-axis direction, in the case of hexadecimal, if a groove 15 with a length exceeding 5 mm is formed, for example, the groove 15 cannot be imaged in one go. In other words, the entire length of the groove 15 cannot be grasped in one image.

[0101] Of course, it is possible for the image processing unit 46 to grasp the overall length of the groove 15 by stitching together a plurality of images to create a single image, but stitching together images places a burden on the image processing unit 46.

[0102] Therefore, it is preferable to set the upper limit of N (a natural number) according to the size of the imaging field of view. For example, if the length of the imaging field of view in the X-axis direction is 4.8 mm, N is preferably 3 or less (i.e., a ternary or quaternary number), and if the length is 8.0 mm, N is preferably 7 or less (i.e., a ternary to octal number).

[0103] Next, a second embodiment will be described. In the second embodiment, a disk-shaped silicon substrate 23 is suction-held by using a chuck table 20 instead of a sub-chuck table 24 (see FIG. 10).

[0104] 10 is a top view of the silicon substrate 23 according to the second embodiment, particularly showing the state after the additional recording step S80. In this embodiment, a disk-shaped silicon substrate (silicon wafer) 23 having a diameter of 200 mm and a thickness of about 0.8 mm is used.

[0105] A central portion of a tape 25 having a diameter larger than that of the silicon substrate 23 is attached to the rear surface side of the silicon substrate 23. One surface of a metal ring-shaped frame 27 is attached to the outer periphery of the tape 25.

[0106] In this manner, a wafer unit 29 is formed in which the silicon substrate 23 is supported by the frame 27 via the tape 25. The wafer unit 29 is housed in a cassette 8, and is transferred to the chuck table 20 when in use.

[0107] The method of using the silicon substrate 23 according to the second embodiment also follows the procedure shown in Fig. 2. In the recording step S30 and the additional recording step S80 of the second embodiment, a plurality of grooves 15 are formed radially on the outer periphery of the upper surface 23a of the silicon substrate 23 along the circumferential direction of the silicon substrate 23.

[0108] In the reading step S60 of this embodiment, the control unit 44 also converts the images of the plurality of grooves 15 into information regarding the cutting conditions in accordance with predetermined rules, so that the operator does not have to input the cutting conditions.

[0109] In addition, the structures, methods, etc. according to the above-described embodiments can be modified as appropriate without departing from the scope of the present invention. For example, instead of the silicon substrates 13 and 23, a substrate made of glass or gallium arsenide (GaAs) may be used. The shape of the substrate may be rectangular or disk-like.

[0110] Incidentally, the correspondence between the numbers specified by the lengths of grooves 15a, 15b, etc. and information 17a, 17b, etc. may be stored in advance in an auxiliary storage device as in the above-described embodiment, or may be provided to the auxiliary storage device via an external storage device such as a USB memory or the Internet, etc. (neither of which are shown in the figures).

[0111] Furthermore, if the control unit 44 is connected to an external server or computer (neither of which are shown), the above-mentioned correspondence may be stored in the memory of the server or computer. In this case, the control unit 44 can access the server or computer to read the information 17 corresponding to the length of each groove 15 and the arrangement of the multiple grooves 15. [Explanation of symbols]

[0112] 2: cutting device, 4: operation panel, 6: monitor, 8: cassette, 10: cassette table 11: wafer, 11a: front surface, 11b: back surface 12: elevator, 14: push-pull arm, 16: guide rail 13, 23: silicon substrate, 13a: upper surface, 13b: lower surface 15,15a,15b,15c,15d,15e,15f,15g,15h:Groove 17, 17a, 17b, 17c, 17d: Information 18: First transport unit 19:Groove, 19a,19b:Position 20: chuck table, 20a: holding surface, 20b: clamp unit 22: table cover, 22a: X-axis direction movement mechanism 23a: upper surface, 25: tape, 27: frame, 29: wafer unit 24: sub-chuck table, 24a: holding surface, 26: microscope camera unit 28: cutting unit, 30: spindle housing, 32: spindle 34: cutting blade, 36: blade cover, 38: nozzle unit 40: second transfer unit, 42: spinner cleaning unit 44: control unit, 46: image processing unit, 48: information conversion unit A1: Loading / unloading area, A2: Cutting area, B: Rectangular area, C: Length, D: Radius E: cutting depth, R: specified direction, Z1, Z2: position

Claims

1. A method of using a substrate in a cutting device having a chuck table for holding a substrate, and a cutting unit having a spindle and a cutting blade attached to a tip of the spindle, the method comprising the steps of: cutting the substrate held by the chuck table with the cutting blade in a thickness direction of the substrate, and detecting a height position of the cutting blade based on a cutting depth, the method comprising the steps of: a step of placing the substrate on the chuck table; a recording step of forming a plurality of grooves on an outer periphery of the substrate with the cutting blade and recording information on the substrate regarding cutting conditions when the cutting blade is used for cutting; A method of using a substrate comprising:

2. 2. The method of claim 1, further comprising, after the recording step, a reading step of imaging the plurality of grooves formed on the substrate and reading information relating to the cutting conditions from the image of the plurality of grooves.

3. The information on the cutting conditions is determined according to a length of each groove and an arrangement of the plurality of grooves, 3. The method for using a substrate according to claim 2, wherein said reading step includes reading information corresponding to the length of each groove and the arrangement of the plurality of grooves from the image.

4. a chopper cut setup step of cutting the cutting blade in the thickness direction of the substrate after the reading step to form a groove for measuring the cutting depth of the cutting blade; an additional recording step of forming a plurality of grooves in the outer periphery of the substrate with the cutting blade after the chopper cut setup step and recording updated information regarding the cutting conditions; Further comprising: A method for using a substrate as described in claim 2 or 3, characterized in that the updated information includes at least one of the number of grooves for measuring cutting depth formed in the substrate and the position of the groove for measuring cutting depth last cut by the cutting blade.

5. 5. The method for using a substrate according to claim 1, wherein the information on the cutting conditions includes a distance between grooves for measuring the cutting depth of the cutting blade.

Images