JP7630889B2 - How to use the board - Google Patents

Description

The present invention relates to a method for using a substrate that is used to detect the height position of a cutting blade.

Electronic devices such as mobile phones and personal computers are equipped with device chips. 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 Integration) are formed on the front side, and then dividing the workpiece into device units.

When dividing a workpiece, for example, the workpiece is cut using 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).

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

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).

JP 2002-59365 A

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 cuts made into the cutting device each time it is used, making the work complicated.

The present invention was made in consideration of these problems, and aims to simplify the input of cutting conditions into the cutting device for the operator.

According to one aspect of the present invention, 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 cuts into the substrate held by the chuck table in the thickness direction of the substrate and detects the height position of the cutting blade based on the cutting depth, is provided, the method of using a substrate comprising a step of placing the substrate on the chuck table and a step of forming a plurality of grooves with the cutting blade on the outer periphery of the substrate and recording information on the cutting conditions when the cutting blade cuts into the substrate.

Preferably, the method of using the substrate further includes, 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.

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 process, information corresponding to the length of each groove and the arrangement of the multiple grooves is read from the image.

In addition, preferably, the method of using the substrate further includes, 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 an additional recording step of forming multiple grooves with the cutting blade on the outer periphery of the substrate after the chopper cut setup step to record updated information regarding the cutting conditions, the updated information including at least one of the number of grooves for measuring the cutting depth formed on the substrate and the position of the groove for measuring the cutting depth finally cut by the cutting blade.

Also, preferably, the information regarding the cutting conditions includes the spacing between grooves for measuring the cutting depth of the cutting blade.

In one embodiment of the method of using a substrate according to the present invention, a cutting blade is used to form multiple grooves on the outer periphery of the substrate, and information regarding the cutting conditions when the cutting blade is used to cut is recorded on the substrate (recording process).

If the cutting device converts the images of the multiple grooves into information about the cutting conditions according to predetermined rules, the operator does not have to input the cutting conditions. This simplifies the input of the cutting conditions into the cutting device.

FIG. FIG. 1 is a flow diagram of a method for using a silicon substrate. FIG. FIG. FIG. 2 is a top view of a silicon substrate. FIG. FIG. 2 is a side view showing the CCS process. FIG. 2 is a top view of the silicon substrate after the CCS process. FIG. 13 is a top view of the silicon substrate after an additional recording process. FIG. 11 is a top view of a substrate according to a second embodiment.

An embodiment of the present invention will be described with reference to the attached 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.

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

The monitor 6 displays a guide screen that guides the operator through operations, 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 both an input device and a display device. In this case, the operation panel 4 may be omitted.

The cutting device 2 cuts a disk-shaped wafer 11 (see FIG. 4) made of a semiconductor material such as silicon. The center of a circular resin tape 25 (dicing tape, see FIG. 10) is attached to the back surface 11b of the wafer 11.

One side of a metal ring-shaped 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, dicing tape, and ring-shaped frame form a wafer unit.

Multiple (e.g., 25) wafer units are stored in one cassette 8, and the cassette 8 is placed on a cassette table 10 provided at the front corner of the cutting device 2. An elevator 12 that can move the cassette table 10 up and down is connected to the bottom of the cassette table 10.

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.

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 .

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

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 rotational drive source (not shown) such as a motor that rotates the chuck table 20 around a predetermined rotation axis is connected below the chuck table 20.

A rectangular table cover 22 is provided between the rotary drive source and the chuck table 20. A rectangular plate-shaped sub-chuck table 24 made of metal is provided on the upper surface of the table cover 22.

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 that connects to the rectangular annular groove is formed closer to the center of the holding surface 24a than the rectangular annular groove.

Negative pressure is transmitted to each groove from a suction source (not shown) such as an ejector. This negative pressure causes the holding surface 24a to suction and hold a rectangular plate-shaped silicon substrate (substrate) 13 made of single crystal silicon. The silicon substrate 13 is used to detect the height position of the cutting blade 34, which will be described later.

The silicon substrate 13 has one surface that is approximately the same size as the holding surface 24a. In this embodiment, the silicon substrate 13 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.

An X-axis direction movement mechanism 22a is provided below the rotary drive source of the chuck table 20. The X-axis direction movement mechanism 22a moves the rotary drive source, the chuck table 20, the table cover 22, the sub-chuck table 24, etc., together along the X-axis direction.

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

An X-axis direction moving table (not shown) is slidably connected to 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 underside of the X-axis direction moving table.

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.

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 .

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.

A ball screw type Y-axis direction movement 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, any area on the front surface 11a side of the wafer 11 located on the holding surface 20a can be imaged. The image captured by the microscope camera unit 26 is sent to the control unit 44, which will be described later.

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 any area on the upper surface 13a of the silicon substrate 13 located on the holding surface 24a is captured. The captured image is sent to the control unit 44.

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.

A part of the cylindrical spindle 32 is rotatably housed in the spindle housing 30. A rotary drive source such as a motor (not shown) 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.

The upper part of the cutting blade 34 is covered by 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.

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. The cutting feed mechanism is also moved along the Y-axis direction together with the cutting unit 28 by a ball screw type indexing feed mechanism (not shown).

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 carry-in/carry-out area _A1 .

After the wafer 11 has been cut, the second transport unit 40 accesses the chuck table 20 arranged in the carry-in/carry-out area _A1 and transports the wafer ₁₁ from the chuck table 20 in the carry-in/carry-out area A1 to the spinner table of the spinner cleaning unit 42.

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

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

Primary storage devices include dynamic random access memory (DRAM), static random access memory (SRAM), read only memory (ROM), etc. Secondary storage devices include flash memory, hard disk drives, solid state drives, etc.

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

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

For example, the length of one pixel in the 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.

The multiple grooves 15 are formed in a portion of the outer periphery of the upper surface 13a of the silicon substrate 13, perpendicular to the linear edge of the silicon substrate 13. In this embodiment, the multiple grooves 15 are formed near the corners of the silicon substrate 13, as shown in FIG. 5.

In this embodiment, each groove 15 is formed using a cutting blade 34, so that each groove 15 has approximately the same width and a predetermined depth (e.g., 50 μm) that does not reach the lower surface 13 b. However, the length of each groove 15 is not necessarily the same.

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.

First, referring to FIG. 6, the numbers indicated by the length of the groove 15 will be explained. 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 the information conversion unit 48 using the length of groove 15a as the reference.

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 groove 15b into the number "3."

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

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

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

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).

The number indicated by the length of groove 15c is expressed in base (N+1) when the number specified by groove 15b is N (N: natural number). In this embodiment, the number indicated by the length of groove 15b is 3, so the number indicated by the length of each of grooves 15c to 15f is expressed in base 4 (=3+1).

In this embodiment, the length of the groove 15c is 1 mm, so that the groove 15c indicates the number "1" in base 4, which corresponds to the decimal number 1 (=4 ⁰ ×1). The decimal number specified by the groove 15c is linked one-to-one to the interval of the grooves 19 for measuring the cutting depth, according to a table, formula, or the like stored in advance in the auxiliary storage device. Therefore, the control unit 44 can read the information 17b of the interval of the grooves 19 based on the image of the groove 15c.

In addition, by forming additional grooves 15d, 15e, 15f, 15g, and 15h (see FIG. 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.

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

The quaternary number "132" corresponds to the decimal number 30 (= ⁴² x 1 + ⁴¹ x 3 + ⁴⁰ x 2). The decimal number specified by grooves 15d, 15e, and 15f is converted into the number of grooves 19 formed in silicon substrate 13 according to a table, formula, etc. pre-stored in the auxiliary storage device. In this way, control unit 44 can read information 17c indicating the number of grooves 19 already formed, based on the image including grooves 15d, 15e, and 15f.

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

Grooves 15g and 15h correspond to information 17d indicating the position (two-dimensional coordinates) on the top surface 13a of the silicon substrate 13 corresponding to the position 19a of the groove 19 where the cutting blade 34 was last cut (Rule 5).

9, the length of groove 15g is 3 mm, so groove 15g represents the number "3" in base 4. Groove 15h is 2 mm, so groove 15h represents the number "2" in base 4. The number "3" in base 4 corresponds to the decimal number 3 (=4 ⁰ ×3), and the number "2" in base 4 corresponds to the decimal number 2 (=4 ⁰ ×2).

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 the 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.

In this embodiment, grooves 15g and 15h are spaced apart by 0.5 mm in the long side direction of silicon substrate 13. In contrast, 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.

When the update information indicated by grooves 15d to 15h is to be further updated, grooves 15d to 15h themselves are not changed, and 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.

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

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 a method of using the silicon substrate 13.

First, as shown in FIG. 1, an operator places an unused silicon substrate 13 (i.e., a substrate on which 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.

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).

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

Figure 3 shows the recording process S30. In the recording process S30, first, the microscope camera unit 26 captures an image of the front corner of the silicon substrate 13, and adjusts the position of the cutting blade 34 in the Y-axis direction relative to the silicon substrate 13.

Then, the lower end of the rotating cutting blade 34 is positioned at a predetermined cutting depth (e.g., 50 μm) from the upper surface 13 a on the outside of the silicon substrate 13, and the sub-chuck table 24 is moved in the processing direction by the X-axis movement mechanism 22 a.

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 spacing between the grooves 15, forming groove 15b in the same manner as groove 15a. Furthermore, groove 15c is formed.

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

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

In the reading process S60, first, the operator places the silicon substrate 13, on which multiple grooves 15a, 15b, and 15c are formed, on the sub-chuck table 24, and the holding surface 24a holds the lower surface 13b of the silicon substrate 13 by suction.

Then, from the images obtained by capturing images of the multiple grooves 15a, 15b, and 15c with the microscope camera unit 26, information 17 relating to the cutting conditions is read according to 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 shows the reading process S60.

In this embodiment, the cutting condition information 17 is recorded by the cutting blade 34 using the multiple grooves 15a, 15b, and 15c, and then the cutting condition information 17 can be read based on the image of the multiple grooves 15.

This allows the cutting device 2 to convert images of multiple grooves 15a, 15b, and 15c into information about the cutting conditions according to predetermined rules, eliminating the need for the operator to input the cutting conditions.

This simplifies the input of cutting conditions to the cutting device 2. It also reduces the time and effort required for the operator to input cutting conditions via the operation panel 4, and also helps to avoid input errors.

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

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

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 that does not reach the holding surface 24a.

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.

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.

The radius D of the cutting blade 34 can be expressed as {h ² + (C/2) ² } ^1/2 from the distance h and the length C. The cutting depth E can be expressed as D - {D ² - (C/2) ² } ^1/2 from the length C and the radius D. 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 contacts the upper surface 13a is calculated to be Z ₁ + E.

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

Figure 9 shows the top surface of the silicon substrate 13 after the additional recording step S80. Note that, for ease of explanation, multiple grooves 19 are shown in Figure 9, but the additional recording step S80 may be performed after forming one groove 19.

By using grooves 15d to 15h, in the next reading step S60, the control unit 44 can automatically read the number of grooves 19 that have been formed and the position of the last groove 19 that was formed. This reduces the time and effort required for the operator to input the cutting conditions via the operation panel 4, and also helps to avoid input errors.

In addition, 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.

For example, if the index amount (information 17b), the size of silicon substrate 13, and the order in which grooves 19 are formed are known, information 17c can be used to identify information 17d, and conversely, information 17d can be used to identify information 17c.

In addition, once the position 19a of the groove 19 where the cutting blade 34 last cut is determined, the control unit 44 can automatically determine the position 19b (shown by the dashed line in FIG. 9) where the next groove 19 will be formed.

By the way, grooves 15 other than grooves 15a and 15b can also be expressed in any (N+1)-ary number. However, in the case of binary numbers (N=1), the number of grooves 15 arranged in parallel becomes relatively large depending on the amount of information to be recorded.

Therefore, it is preferable that the lower limit of N (a natural number) be 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, it is possible to adopt, for example, hexadecimal numbers (N=15).

However, the size of the imaging field of view 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, so in the case of hexadecimal, if a groove 15 with a length exceeding, for example, 5 mm is formed, 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.

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

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).

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

Figure 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.

The center of tape 25, which has a diameter larger than that of silicon substrate 23, is attached to the back side of silicon substrate 23. One surface of a metal ring-shaped frame 27 is attached to the outer periphery of tape 25.

In this way, 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 stored in a cassette 8 and is transported to the chuck table 20 when in use.

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.

In the reading step S60 of this embodiment, the control unit 44 also converts the images of the multiple grooves 15 into information related to the cutting conditions according to predetermined rules, eliminating the need for the operator to input the cutting conditions.

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) can be used. The shape of the substrate can be rectangular or disk-shaped.

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 addition, 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 information 17 corresponding to the length of each groove 15 and the arrangement of multiple grooves 15.

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 rails 13, 23: silicon substrate, 13a: top surface, 13b: bottom surface 15, 15a, 15b, 15c, 15d, 15e, 15f, 15g, 15h: grooves 17, 17a, 17b, 17c, 17d: information 18: first transport unit 19: grooves, 19a, 19b: positions 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 transport unit, 42: spinner cleaning unit 44: control unit, 46: image processing unit, 48: information conversion unit _A1 : load/unload area, _A2 : cutting area, B: rectangular area, C: length, D: radius, E: cutting depth, R: specified direction, _Z1 , _Z2 : position

Claims (5)

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: The method for using the substrate according to claim 1 further comprises, after the recording step, 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. 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. 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. A method for using a substrate according to any one of claims 1 to 4, characterized in that the information on the cutting conditions includes the distance between grooves for measuring the cutting depth of the cutting blade.

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