JP7650592B2 - Kerf quality tolerance change method, program and processing device - Google Patents

Description

The present invention relates to a kerf quality tolerance change method for changing the tolerance range of an item related to the kerf processing quality that is set in order to perform a kerf check to check the processing quality of a kerf formed on a workpiece, a program for causing a computer to execute this kerf quality tolerance change method, and a processing device for executing this kerf quality tolerance change method.

Chips for devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integration) are essential components in various electronic devices such as mobile phones and personal computers. Such chips are manufactured, for example, by forming a large number of devices on the surface of a wafer made of semiconductor material, and then dividing the wafer using a processing device into areas containing individual devices.

Examples of processing devices that divide workpieces such as wafers include cutting devices and laser processing devices. Cutting devices have a holding table that holds the workpiece and a cutting unit with an annular cutting blade, and cut the workpiece by rotating the cutting blade and bringing it into contact with the workpiece. Laser processing devices have a holding table that holds the workpiece and a laser processing unit that can irradiate a laser beam, and irradiate the workpiece with the laser beam to cause laser ablation.

Such processing devices generally have an imaging unit for capturing an image of the workpiece and aligning the workpiece with the processing unit (cutting unit or laser processing unit). This imaging unit may also be used to check the processing marks formed on the workpiece by the processing unit.

For example, the quality of the kerf processing may be checked (kerf check) using an image of the kerf formed on the workpiece by imaging the kerf (see, for example, Patent Document 1). If an abnormality in the quality of the kerf processing is discovered during the kerf check, for example, the operation of the processing device is stopped and this is notified to the operator. This makes it possible to discover problems with the processing of the workpiece in the processing device at an early stage and minimize the resulting adverse effects.

JP 2013-74198 A

The kerf check is performed, for example, by using an image of the kerf to calculate the values (determined values) of multiple items related to the kerf processing quality, and determining whether or not each determined value is within a preset tolerance range. If any of the determined values is a value (error value) that is not within the tolerance range, it is determined that there is an abnormality in the kerf processing quality in the processing device.

However, the requirements for kerf processing quality may vary depending on the type of workpiece being processed. Therefore, even if the kerf check determines that there is an abnormality in the kerf processing quality and the operation of the processing device is stopped, the kerf processing quality that is actually required may be met.

In such cases, it is necessary to change the tolerance of at least one of the multiple items related to the kerf processing quality. However, for an operator who is not familiar with operating the processing device, it may not be easy to identify the item whose tolerance should be changed and the tolerance that should be set by the change.

In view of this, the object of the present invention is to provide a method for changing the kerf quality tolerance range in order to properly perform a kerf check in a processing device, a program for causing a computer to execute this method for changing the kerf quality tolerance range, and a processing device in which this method for changing the kerf quality tolerance range is executed.

According to one aspect of the present invention, there is provided a kerf quality tolerance range changing method for changing an allowable range of an item related to the machining quality of a kerf formed in a workpiece, which is set for performing a kerf check to check the machining quality of the kerf formed in the workpiece, the method including: a calculation step of calculating a judged value of the item using an image of the kerf formed by imaging the kerf formed in the workpiece; a determination step of determining whether the judged value is an error value not included in the allowable range; and a change step of changing the allowable range so as to include the judged value judged to be the error value in the determination step, wherein the allowable range after the change includes a value that is more deviated from the allowable range before the change than the judged value by one minimum unit when the allowable range is changed, and does not include a value that is more deviated from the allowable range before the change than the judged value by two minimum units .

In addition, in the method for changing the kerf quality tolerance range of the present invention, the item is preferably the kerf width, the chipping size, the kerf deviation amount, or the kerf recognition value.

According to another aspect of the present invention, there is provided a program for causing a computer to execute a kerf quality tolerance changing method for changing an allowable range of an item related to the machining quality of a kerf, which is set for performing a kerf check to check the machining quality of the kerf formed in a workpiece, the kerf quality allowable range changing method including: a calculation step of calculating a determined value of the item using an image of the kerf formed by imaging the kerf formed in the workpiece; a determination step of determining whether the determined value is an error value not included in the allowable range; and a change step of changing the allowable range so as to include the determined value determined to be the error value in the determination step, wherein the allowable range after the change includes a value that is more deviated from the allowable range before the change than the determined value by one minimum unit when the allowable range is changed, and does not include a value that is more deviated from the allowable range before the change than the determined value by two minimum units .

According to yet another aspect of the present invention, there is provided a processing device comprising: a holding table for holding a workpiece; a processing unit for forming a kerf in the workpiece held on the holding table; an imaging unit for imaging the kerf to form an image of the kerf; and a control unit for changing an allowable range of an item related to the processing quality of the kerf which is set to perform a kerf check to confirm the processing quality of the kerf formed in the workpiece, the control unit including: a calculation unit for calculating a determined value of the item using the image of the kerf; a determination unit for determining whether the determined value is an error value not included in the allowable range; and a change unit for changing the allowable range so as to include the determined value determined by the determination unit to be the error value, wherein the allowable range after the change includes values that are further out of the allowable range before the change than the determined value by one minimum unit when the allowable range is changed, and does not include values that are further out of the allowable range before the change than the determined value by two minimum units .

Furthermore, in the processing device of the present invention, it is preferable that the processing unit is a cutting unit equipped with an annular cutting blade, and the kerf is formed by the cutting blade.

Alternatively, in the processing device of the present invention, it is preferable that the processing unit is a laser processing unit capable of irradiating the workpiece with a laser beam, and the kerf is formed by irradiating the workpiece with the laser beam from the laser processing unit.

In the present invention, when a judged value for an item related to the kerf processing quality, which is calculated using an image of the kerf formed on the workpiece by imaging the kerf, is an error value, the tolerance range for that item is changed to include this judged value. This makes it possible to perform the kerf check appropriately.

FIG. 1 is a diagram illustrating an example of a system. FIG. 2 is a block diagram illustrating a computer. FIG. 3 is a block diagram showing functional units included in the computer. FIG. 4 is a perspective view illustrating an example of a cutting device. FIG. 5 is a sequence diagram showing a schematic diagram of a method for changing the kerf quality allowable range executed in the system. FIG. 6 is a flow chart that illustrates a part of the operation flow of the processing device in the method for changing the kerf quality allowable range. FIG. 7 is a diagram showing an example of a screen showing the result of the kerf check. FIG. 8 is a flow chart that illustrates a part of the operation flow of a computer in the method for changing the kerf quality tolerance range. FIG. 9 is a sequence diagram showing a schematic diagram of a method for changing the kerf quality allowable range executed in the processing device. FIG. 10 is a flow chart that illustrates a part of the operation flow of the processing device in the method for changing the kerf quality allowable range. FIG. 11 is a flow chart that illustrates a part of the operation flow of the processing device in the method for changing the kerf quality allowable range. FIG. 12 is a perspective view illustrating an example of a laser processing apparatus.

An embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram showing a schematic diagram of an example of a system according to this embodiment. The system shown in FIG. 1 includes a computer 2 and a processing device 4. The computer 2 and the processing device 4 are provided separately from each other and can communicate with each other via a network 6.

This network 6 is configured, for example, by wireless communication or wired communication. Alternatively, the network 6 may be configured by a combination of wireless communication and wired communication. Also, in FIG. 1, for convenience, only one computer 2 and one processing device 4 are shown, but the computer 2 may be capable of communicating with multiple processing devices 4, and the processing device 4 may be capable of communicating with multiple computers 2.

For example, the computer 2 may be configured to be able to communicate with multiple processing devices 4 of the same or different types. Furthermore, the processing device 4 may be configured to be able to communicate with multiple computers 2 each performing a different process, and to communicate with one of the multiple computers 2 depending on the process performed by the processing device 4.

Then, the processing device 4 transmits to the computer 2, for example, an electrical signal corresponding to the image of the kerf and an electrical signal corresponding to the tolerance ranges (kerf check conditions) of each of a number of items related to the kerf processing quality. In addition, the computer 2 transmits to the processing device 4, for example, an electrical signal corresponding to the kerf check conditions under which the kerf processing quality is determined to be normal when a kerf check is performed using the image of the kerf.

Figure 2 is a block diagram showing a computer 2 included in the system shown in Figure 1. The computer 2 shown in Figure 2 includes a central processing unit (CPU) 8, a storage device 10, an output device 12, an input device 14, and a communication interface 16. The storage device 10 also includes a main storage device 10a with excellent rewrite speed and an auxiliary storage device 10b with large storage capacity. These components are connected via a bus 18 so that they can send and receive electrical signals to each other.

The CPU 8 reads and executes various programs stored in the auxiliary storage device 10b of the storage device 10. For example, when an electrical signal corresponding to a kerf image and an electrical signal corresponding to the kerf check conditions are transmitted from the processing device 4 to the computer 2, the CPU 8 reads a program for changing the kerf quality tolerance range from the auxiliary storage device 10b, performs calculations, and changes the kerf check conditions.

Specifically, the CPU 8 changes the kerf check conditions so that the kerf processing quality is determined to be normal when a kerf check is performed using the image of the kerf. Furthermore, the CPU 8 controls the output device 12 to notify the user of the computer 2 of the changed kerf check conditions. Furthermore, the CPU 8 transmits an electrical signal corresponding to the changed kerf check conditions to the processing device 4 via the communication interface 16 in response to the operation of the input device 14 by the user of the computer 2.

The main memory device 10a of the memory device 10 is composed of volatile memory such as DRAM (Dynamic Random Access Memory) or SRAM (Static Random Access Memory). The auxiliary memory device 10b is composed of non-volatile memory such as SSD (Solid State Drive) (NAND type flash memory) or HDD (Hard Disk Drive) (magnetic memory device).

The output device 12 is composed of at least one of a display, a printer, a speaker, etc. The input device 14 is composed of at least one of a keyboard, a mouse, a touch pad, a microphone, etc. The output device 12 and the input device 14 may be integrated.

In other words, the output device 12 and the input device 14 may be replaced with an input/output device such as a touch panel. The communication interface 16 is composed of at least one of a communication circuit (such as an analog-to-digital conversion circuit (ADC) and a digital-to-analog conversion circuit (DAC)) and an input/output (I/O) port.

Figure 3 is a block diagram showing the functional units included in the computer 2. The computer 2 shown in Figure 3 has a calculation unit 20, a determination unit 22, and a change unit 24. The calculation unit 20 has a function of calculating the values (determined values) of multiple items related to the processing quality of the kerf using an image of the kerf formed on the workpiece.

These multiple items include the kerf width, the chipping size, the amount of kerf deviation, and the kerf recognition value (kerf-likeness). The kerf width is evaluated, for example, as the distance between a pair of straight lines that pass through the innermost of the pair of inner surfaces that define the kerf and run along the direction in which the kerf extends. The chipping size is evaluated, for example, as the maximum width of the chipping that spreads outward from one or the other of the pair of straight lines (the spread of the kerf) or the chipping area (the number of pixels that make up the chipping area).

The amount of kerf misalignment is evaluated, for example, as the distance between a straight line located at the center of a pair of inner surfaces that define the kerf in the ideal position and aligned along the direction in which the kerf extends, and a straight line located at the center of a pair of inner surfaces that define the actual kerf and aligned along the direction in which the kerf extends. The kerf recognition value is evaluated, for example, as the difference in brightness (contrast) between a pair of pixels that constitute the image of the kerf, that are adjacent in a direction perpendicular to the direction in which the kerf extends, and that have the greatest change in brightness in this direction. Note that this kerf recognition value is a value that depends on the inclination of the pair of inner surfaces that define the actual kerf, etc.

The determination unit 22 also determines whether each of the multiple determined values calculated by the calculation unit 20 is a value (error value) that is not included in the allowable range of each of the multiple items related to the kerf processing quality. The change unit 24 also changes the allowable range of the item so as to include the determined value determined by the determination unit 22 to be an error value.

Figure 4 is a perspective view showing a schematic diagram of the processing device 4 included in the system shown in Figure 1. In Figure 4, some of the components of the processing device 4 are shown in functional blocks. In addition, the X-axis direction (front-back direction) and the Y-axis direction (left-right direction) shown in Figure 4 are directions perpendicular to each other on a horizontal plane, and the Z-axis direction (up-down direction) is a direction perpendicular to the X-axis direction and the Y-axis direction (vertical direction).

The processing device 4 shown in FIG. 4 includes a base 26 that supports each component. An opening 26a is formed in the front corner of the base 26, and within this opening 26a is provided a cassette support table 28 that is raised and lowered by a lifting mechanism (not shown). A cassette 30 that contains multiple workpieces 11 is placed on the upper surface of the cassette support table 28. Note that, for convenience, only the outline of the cassette 30 is shown in FIG. 4.

The workpiece 11 is, for example, a disk-shaped wafer made of a semiconductor material such as silicon. There are no limitations on the material, shape, structure, size, etc. of the workpiece 11. The workpiece 11 may be made of a semiconductor material other than silicon (e.g., silicon carbide (SiC) or gallium nitride (GaN)). A plurality of mutually intersecting planned division lines (streets) are set on the surface 11a side of the workpiece 11.

Devices such as ICs or LSIs are formed on the front surface 11a of each area partitioned by a plurality of planned division lines. A dicing tape (adhesive tape) 13, which has a diameter longer than that of the workpiece 11, is attached to the back surface 11b of the workpiece 11. A metal ring-shaped frame 15 is attached to the outer periphery of the dicing tape 13. The workpiece 11 is stored in the cassette 30 as a workpiece unit 17 integrated with the frame 15 via the dicing tape 13.

A rectangular opening 26b with its longitudinal direction along the X-axis direction is formed on the side of the cassette support base 28, and within this opening 26b are arranged a ball screw type X-axis movement mechanism (not shown), a table cover 32 that covers the X-axis movement mechanism, and a dustproof/waterproof cover 34. This X-axis movement mechanism has an X-axis movement table (not shown) covered by the table cover 32, and moves this X-axis movement table in the X-axis direction.

A holding table 36 is fixed to the top surface of this X-axis moving table so that it is exposed from the table cover 32. Therefore, when the X-axis moving mechanism moves the X-axis moving table, the table cover 32 moves along the X-axis direction together with the holding table 36, and the dust-proof and drip-proof cover 34 expands and contracts in accordance with the moving table cover 32.

The holding table 36 has a disk-shaped frame made of a metal material such as stainless steel. The frame has a disk-shaped bottom wall and an annular side wall extending upward from the outer periphery of the bottom wall. The bottom wall and the side wall define a recess on the upper surface of the frame, and a disk-shaped porous plate made of ceramics or the like is fixed in this recess.

Furthermore, this porous plate has an upper surface parallel to the X-axis direction and the Y-axis direction, and its lower surface side is connected to a suction source (not shown) such as an ejector via a suction path (not shown) and a valve formed inside the frame of the holding table 36. When the valve is opened while this suction source is operating, negative pressure is generated in the space near the upper surface of the porous plate.

Therefore, the upper surface of this porous plate functions as the holding surface of the holding table 36 that holds the workpiece 11. In other words, when the workpiece 11 is placed on the upper surface of this porous plate via the dicing tape 13 and negative pressure is generated in the space near the upper surface of the porous plate, the workpiece 11 is sucked and held by the holding table 36.

Furthermore, clamps 38 for fixing the frame 15 are provided around the periphery of the frame of the holding table 36, and when the workpiece 11 is held by suction on the holding table 36, the frame 15 is also fixed by these clamps 38. The holding table 36 is also connected to a rotational drive source (not shown) such as a motor that rotates the holding table 36 around a rotation axis that passes through the center of its holding surface and is parallel to the Z-axis direction.

A support structure 40 is provided on the base 26, and is arranged to straddle the opening 26b. Specifically, the support structure 40 has a pair of flat upright portions 40a, 40b provided on the base 26 so as to sandwich the opening 26b, and a flat bridge portion 40c provided on the pair of upright portions 40a, 40b so as to span the space above the opening 26b.

A first Y-axis moving mechanism 42a and a second Y-axis moving mechanism 42b are provided on the front (surface) side of the bridge section 40c. The first Y-axis moving mechanism 42a and the second Y-axis moving mechanism 42b are fixed to the front of the bridge section 40c and share a pair of guide rails 44 that extend along the Y-axis direction. A moving plate 46a and a moving plate 46b are provided on the front (surface) side of the pair of guide rails 44.

The movable plate 46a is closer to the erected portion 40a than the movable plate 46b, and the movable plate 46b is closer to the erected portion 40b than the movable plate 46a. The movable plates 46a and 46b are connected to the front (surface) side of the pair of guide rails 44 in a manner that allows them to slide along the guide rails 44, within a range where they do not come into contact with each other.

In addition, screw shafts 48a and 48b extending along the Y-axis direction are disposed between the pair of guide rails 44. A motor 50a for rotating the screw shaft 48a is connected to the end of the screw shaft 48a facing the upright portion 40b. Similarly, a motor (not shown) for rotating the screw shaft 48b is connected to the end of the screw shaft 48b facing the upright portion 40a.

The surface of the screw shaft 48a, on which the helical grooves are formed, is provided with a nut portion (not shown) that accommodates balls that roll on the surface of the rotating screw shaft 48a, forming a ball screw. That is, when the screw shaft 48a rotates, the balls circulate through the nut member, and the nut portion moves along the Y-axis direction. This nut portion is also fixed to the rear surface (back surface) of the moving plate 46a. Therefore, when the screw shaft 48a is rotated by the motor 50a, the moving plate 46a moves along the Y-axis direction together with the nut portion.

Similarly, a nut portion (not shown) that accommodates balls that roll on the surface of the rotating screw shaft 48b is provided on the surface of the screw shaft 48b where the helical grooves are formed, forming a ball screw. That is, when the screw shaft 48b rotates, the balls circulate through the nut member, and the nut portion moves along the Y-axis direction. In addition, this nut portion is fixed to the rear surface (back surface) side of the moving plate 46b. Therefore, when the screw shaft 48b is rotated by a motor connected to the end of the screw shaft 48b on the side of the erected portion 40a, the moving plate 46b moves along the Y-axis direction together with the nut portion.

The first Y-axis moving mechanism 42a includes a ball screw (screw shaft 48a, etc.) and a motor 50a for moving the moving plate 46a along the Y-axis direction. The second Y-axis moving mechanism 42b includes a ball screw (screw shaft 48b, etc.) for moving the moving plate 46b along the Y-axis direction, and a motor connected to the end of the screw shaft 48b on the erected portion 40a side.

A Z-axis movement mechanism 52 is provided on the front surface (surface) of each of the moving plates 46a and 46b. The Z-axis movement mechanism 52 is fixed to the front surface (surface) of the moving plate 46a or the moving plate 46b, and has a pair of guide rails 54 that extend along the Z-axis direction. A moving plate 56 is connected to the front surface (surface) of the pair of guide rails 54 in a manner that allows it to slide along the pair of guide rails 54.

A screw shaft 58 extending along the Z-axis direction is disposed between the pair of guide rails 54. A motor 60 for rotating the screw shaft 58 is connected to the upper end of the screw shaft 58. A nut portion (not shown) that accommodates balls that roll on the surface of the rotating screw shaft 58 is provided on the surface of the screw shaft 58 on which the helical groove is formed, forming a ball screw.

In other words, when the screw shaft 58 rotates, the balls circulate inside the nut portion, causing the nut portion to move along the Z-axis direction. This nut portion is also fixed to the rear (back) side of the moving plate 56. Therefore, when the screw shaft 58 is rotated by the motor 60, the moving plate 56 moves along the Z-axis direction together with the nut portion.

A cutting unit (processing unit) 62 that cuts the workpiece 11 is provided below the moving plate 56. The cutting unit 62 has a cylindrical spindle housing that extends along the Y-axis direction. A spindle that extends in the Y-axis direction is housed in this spindle housing. This spindle is supported by the spindle housing in a rotatable state.

The tip of the spindle is exposed outside the spindle housing, and a cutting blade 64 with an annular cutting edge is attached to this tip. The spindle housing also contains a rotational drive source (not shown) such as a motor that is connected to the base end of the spindle. Therefore, when the spindle is rotated by this rotational drive source, the cutting blade 64 rotates around a straight line along the Y-axis direction as its axis of rotation.

The cutting blade 64 is, for example, a hub-type cutting blade. A hub-type cutting blade is composed of an annular base made of metal or the like and an annular cutting edge formed along the outer periphery of the base. The cutting edge of this cutting blade is composed of an electroformed grinding wheel in which abrasive grains made of diamond or cubic boron nitride (cBN) or the like are fixed with a binder such as nickel.

Alternatively, the cutting blade 64 may be a washer-type cutting blade. A washer-type cutting blade is composed of an annular cutting edge with abrasive grains fixed by a binder such as metal, ceramic, or resin.

An imaging unit 66 is provided in front of the cutting unit 62. The imaging unit 66 has, for example, a light source such as an LED (Light Emitting Diode), an objective lens, and an imaging element such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor.

A cleaning unit 68 is provided on the side of the opening 26b of the base 26 opposite the opening 26a. The cleaning unit 68 includes a spinner table 70 that holds the workpiece 11 via the dicing tape 13 within a cylindrical cleaning space. The top surface of the spinner table 70 is a surface that is generally parallel to the horizontal plane (XY plane).

The lower part of the spinner table 70 is connected to a suction source (not shown) such as an ejector via a flow path (not shown) and a valve (not shown) formed inside the spinner table 70. When the valve is opened while the suction source is operating, negative pressure is generated in the space near the upper surface of the spinner table 70. Therefore, the upper surface of the spinner table 70 functions as a holding surface that holds the workpiece 11.

In addition, clamps for fixing the frame 15 are provided around the periphery of the spinner table 70, and when the workpiece 11 is held by suction on the spinner table 70, the frame 15 is also fixed by these clamps. The spinner table 70 is also connected to a rotational drive source (not shown) such as a motor that rotates the spinner table 70 around a rotation axis that passes through the center of its holding surface and is parallel to the Z-axis direction.

A nozzle 72 is disposed above the spinner table 70, which supplies a cleaning fluid (e.g., a mixed fluid of water and air) toward the workpiece 11 held by the spinner table 70. In the processing device 4, while the spinner table 70 holds the workpiece 11, the workpiece 11 can be cleaned by supplying fluid from the nozzle 72 while rotating the spinner table 70.

A cover 74 is provided on the upper side of the base 26 to cover each component arranged on the base 26. In FIG. 4, only the outline of the cover 74 is shown by a two-dot chain line. A touch panel 76 is provided on the side of the cover 74 to display various information related to the processing device 4.

The touch panel 76 is composed of, for example, a touch sensor that functions as an input device for inputting instructions from the operator to the processing device 4, and a display that functions as an output device for outputting various information. The touch sensor is, for example, a capacitive touch sensor or a resistive touch sensor. The display is, for example, a liquid crystal display or an organic EL (Electro Luminescence) display.

That is, the touch panel 76 functions as a user interface, and the operator can operate the processing device 4 by touching the surface of the touch panel 76. Note that the touch panel 76 may be replaced with an output device and an input device that are independent of each other. For example, the touch panel 76 may be replaced with a display, a keyboard, and a mouse.

A warning light (pilot lamp) 78 is provided on the top surface of the cover 74. The warning light 78 lights up or flashes when an error (abnormality) occurs in the processing device 4 to notify the operator of the occurrence of the error. For example, the warning light 78 lights up when the processing quality of the kerf is determined to be abnormal when a kerf check is performed using an image of the kerf. The warning light 78 may be replaced with a speaker that emits a sound when an abnormality occurs in the processing device 4, or may be provided together with this speaker.

The operation of each component of the processing device 4 described above is controlled by a control unit 80. The control unit 80 includes, for example, a CPU, a storage device including a main storage device (volatile memory) and an auxiliary storage device (non-volatile memory), and a communication interface. The control unit 80 and the touch panel 76 constitute a computer similar to the computer 2 shown in FIG. 2.

The auxiliary storage device of the control unit 80 stores a program for performing a kerf check using an image of the kerf formed on the workpiece 11. Therefore, the CPU of the control unit 80 can read out this program and perform a kerf check in response to the operator's operation on the touch panel 76. As a result, if the CPU determines that the processing quality of the kerf is abnormal, the CPU can, for example, turn on a warning light 78 and stop processing of the workpiece 11 in the processing device 4.

Figure 5 is a sequence diagram that shows a schematic diagram of a method for changing the kerf quality tolerance range executed in the system shown in Figure 1. In this method, first, the workpiece 11 is held by the holding table 36 in the processing device 4 (holding step: S1). Specifically, after the workpiece 11 is placed on the holding surface of the holding table 36 via the dicing tape 13, negative pressure is generated in the space near the holding surface of the holding table 36 to suck and hold the workpiece 11 to the holding table 36, and the frame is fixed with a clamp 38.

Once the holding step (S1) is completed, the cutting unit 62 forms a kerf in the workpiece 11 (kerf forming step: S2). This kerf forming step (S2) is performed, for example, in the following order: First, the X-axis movement mechanism adjusts the position of the holding table 36 in the X-axis direction so that the cutting blade 64 and the workpiece 11 are spaced apart in the X-axis direction.

Next, the rotary drive source rotates the holding table 36 so that the planned dividing line (street) of the workpiece 11 is parallel to the Y-axis direction. Next, the first Y-axis moving mechanism 42a or the second Y-axis moving mechanism 42b adjusts the position of the cutting unit 62 in the Y-axis direction so that this street is positioned in the X-axis direction when viewed from the cutting blade 64.

Then, the Z-axis movement mechanism 52 adjusts the position of the cutting unit 62 in the Z-axis direction so that the bottom end of the cutting blade 64 of the cutting unit 62 is lower than the back surface 11b of the workpiece 11 and higher than the holding surface of the holding table 36. Then, the rotary drive source of the cutting unit 62 is operated to rotate the cutting blade 64.

Next, while rotating the cutting blade 64, the X-axis movement mechanism moves the holding table 36 along the X-axis direction so that the cutting blade 64 passes from one end of the street to the other. This forms a kerf that penetrates the workpiece 11 and exposes the dicing tape 13.

When the kerf forming step (S2) is completed, the kerf is imaged by the imaging unit 66 (imaging step: S3). This forms an image of the kerf. At this time, the CPU of the control unit 80 may, for example, control the touch panel 76 to display the image of the formed kerf.

Once the imaging step (S3) is completed, a kerf check is performed using the image of the kerf (kerf check step: S4). Figure 6 is a flow chart that shows a schematic of the operation flow of the processing device 4 when performing the kerf check step (S4). In the kerf check step (S4), the CPU of the control unit 80 uses the image of the kerf to calculate the values (determined values) of each of a number of items related to the processing quality of the kerf.

Then, the CPU judges whether each determined value is within a preset tolerance range (whether it satisfies the kerf check conditions). As a result, if at least one determined value does not satisfy the kerf check conditions (an error has occurred) (S5: YES), the CPU transmits an electrical signal corresponding to the kerf image used in the kerf check and an electrical signal corresponding to the kerf check conditions to the computer 2 (transmission step: S6).

In this case, the CPU may turn on a warning light 78 to notify the operator of the processing device 4 that the kerf processing quality is abnormal, and may also control the touch panel 76 to display the results of the kerf check. In this case, these electrical signals may be automatically transmitted from the processing device 4 to the computer 2, or may be transmitted from the processing device 4 to the computer 2 in response to the operation of the touch panel 76 by the operator of the processing device 4.

When the computer 2 receives the electrical signal corresponding to the image of the kerf and the electrical signal corresponding to the kerf check conditions, the CPU 8 of the computer 2 reads out a program for changing the kerf quality tolerance range from the auxiliary storage device 10b and performs calculations to change the kerf check conditions. Specifically, the calculation unit 20 of the computer 2 first uses the image of the kerf to calculate the respective judged values of multiple items related to the kerf processing quality (calculation step: S7).

At this time, in computer 2, the results of the kerf check may be notified to the user of computer 2 via output device 12. For example, the CPU 8 of computer 2 may control the display (output device 12) to display the results of the kerf check on the display.

Figure 7 is a schematic diagram showing an example of a screen showing the results of the kerf check displayed on the display. The image 82 shown in Figure 7 includes an image 84 used in the kerf check. This image 84 includes a kerf 84c formed on a planned division line (street) 84b located between a pair of adjacent devices 84a formed on the front surface 11a side of the workpiece 11.

Image 84 also includes multiple items related to the kerf processing quality ("kerf score," "off-center," "kerf width," "maximum kerf width," "maximum kerf piece width," "maximum chipping size," and "chipping area") 86a and their values (determined values) 86b. Each item 86a will be explained below.

First, the "kerf score" is an index that represents the kerf recognition value (kerf-likeness). Specifically, the "kerf score" is a score that represents the difference in brightness (contrast) between a pair of pixels that make up the image 84 of the kerf 84c, that are adjacent in a direction perpendicular to the direction in which the kerf 84c extends, and that have the greatest change in brightness in this direction.

This "kerf score" is a value that depends on factors such as the inclination of the pair of inner surfaces that define the kerf 84c. For example, the "kerf score" is calculated by setting the difference in brightness between the brightest pixel and the least brightest pixel among the multiple pixels that make up the kerf 84c and the remaining streets 84b in a direction perpendicular to the direction in which the kerf 84c extends as 100 points. Furthermore, it is recognized here that the boundary between the kerf 84c and the remaining streets 84b exists between the pair of pixels, and the determined values of the other items 86a are calculated.

"Off-center" is an index that indicates the amount of deviation of the kerf 84c. Specifically, "off-center" is the distance between a straight line that is located in the center of a pair of inner sides that define the kerf in the ideal position and that runs along the direction in which the kerf extends, and a straight line that is located in the center of a pair of inner sides that define the actual kerf 84c and that runs along the direction in which the kerf 84c extends.

The "kerf width" refers to the distance between a pair of straight lines that pass through the innermost of the pair of inner surfaces that define the kerf 84c and that run along the direction in which the kerf 84c extends. In short, the "kerf width" refers to the width of the kerf 84c along the direction in which the kerf 84c extends, ignoring chipping that occurs on both sides of the kerf 84c.

The "maximum kerf width" is the maximum width of the kerf 84c along a direction perpendicular to the direction in which the kerf 84c extends. In short, the "maximum kerf width" is the maximum width of the kerf 84c including chipping. The "maximum kerf piece width" is the maximum width between the line that is located in the center of the pair of lines used to calculate the "kerf width" and that is along the direction in which the kerf 84c extends, and the boundary between the kerf 84c and the remaining street 84b.

The "maximum chipping size" is the maximum width between one or the other of a pair of straight lines used to calculate the "kerf width" and the boundary between the kerf 84c and the remaining streets 84b located outside of the pair of straight lines. The "chipping area" is the number of pixels (area) that make up the area surrounded by one or the other of a pair of straight lines used to calculate the "kerf width" and the boundary between the kerf 84c and the remaining streets 84b located outside of the pair of straight lines.

When the calculation step (S7) is completed, the judgment unit 22 of the computer 2 judges whether or not the judged values of each of the multiple items 86a are error values that are not included in the allowable range (judgment step: S8). Specifically, the judged values calculated by the calculation unit 20 are compared with the allowable ranges (kerf check conditions) of each of the multiple items related to the kerf processing quality transmitted from the processing device 4. Table 1 is a table that shows a schematic example of the kerf check conditions transmitted from the processing device 4.

As a result of this comparison, the judgment unit 22 of the computer 2 judges that the judged value for the maximum chipping size (0.012 mm) is an error value (over 0.010 mm) and that the other items 86a are not error values. At this time, the computer 2 may notify the user of the computer 2 of the items 86a whose judged values are error values via the output device 12. For example, the CPU 8 of the computer 2 may control the display so that the items 86a whose judged values are error values are displayed in a different color from the other items 86a.

When the judgment step (S8) is completed, the change unit 24 of the computer 2 changes the allowable range (kerf check conditions) of the item 86a to include the judged value (0.012 mm), which is an error value (changing step: S9). Figure 8 is a flow chart that shows a schematic operation flow of the computer 2 when performing the changing step (S9). In the changing step (S9), for example, the kerf check conditions shown in Table 1 are changed to the kerf check conditions shown in Table 2.

Specifically, in this change step (S9), the tolerance range (kerf check conditions) is changed so that a value (0.013 mm) that is outside the pre-change tolerance range (0.010 mm or less) by one smallest unit (0.001 mm for maximum chipping size) is included, and a value (0.014 mm) that is outside the pre-change tolerance range by two smallest units is not included.

If the user of computer 2 believes that the changed kerf check conditions can ensure the desired kerf processing quality (can be applied as the kerf check conditions of processing device 4) (S10: YES), the CPU 8 of computer 2 transmits an electrical signal corresponding to the changed kerf check conditions to processing device 4 in response to the user's operation of input device 14 (transmission step: S11).

When the processing device 4 receives an electrical signal corresponding to the changed kerf check conditions, the CPU of the control unit 80 of the processing device 4 updates the kerf check conditions stored in the storage device (auxiliary storage device) of the control unit 80 (update step: S12). This makes it possible to properly perform the kerf check in the processing device 4.

The above-mentioned method for changing the kerf quality tolerance range is one aspect of the present invention, and the present invention also includes inventions having features different from this method. For example, in the present invention, information may be exchanged between the computer 2 and the processing device 4 using a non-transitory recording medium such as a portable Universal Serial Bus (USB) flash drive without going through the network 6.

That is, after the kerf check step (S4) shown in FIG. 5, electrical signals may be exchanged in the following order. First, a non-temporary recording medium is connected to the processing device 4, and then electrical signals corresponding to the kerf image and electrical signals corresponding to the kerf check conditions are stored in this recording medium. Next, the recording medium is removed from the processing device 4, transported, and connected to the computer 2. Next, the electrical signals stored in this recording medium are stored in the storage device 10 of the computer 2.

Similarly, after the change step (S9) shown in FIG. 5, electrical signals may be exchanged in the following order. First, a non-transient recording medium is connected to the computer 2, and then an electrical signal corresponding to the changed kerf check conditions is stored in the storage device. Next, the recording medium is removed from the computer 2, transported, and connected to the processing device 4. Next, the electrical signal stored in the recording medium is stored in a storage device included in the control unit 80 of the processing device 4.

In the present invention, all steps of the kerf quality tolerance change method may be executed in the processing device 4. FIG. 9 is a sequence diagram showing a schematic diagram of the kerf quality tolerance change method executed in the processing device 4. In this method, first, a program for executing the kerf quality tolerance change method is transmitted to the processing device 4 from the computer 2 (the storage device 10) or a non-transitory recording medium that stores the program.

Then, in the processing device 4, this program is stored in the storage device of the control unit 80. Note that this program does not need to be stored in the storage device of the control unit 80, as long as it is in a state where the CPU of the control unit 80 can read it. For example, if a non-transitory recording medium that stores this program is connected to the processing device 4, the storage device of the control unit 80 does not need to store this program.

As a result, the control unit 80 of the processing device 4 has the same functional units as the computer 2 shown in FIG. 3. That is, the control unit 80 capable of reading this program includes a calculation unit that calculates the values (determined values) of multiple items related to the processing quality of the kerf using an image of the kerf formed on the workpiece, a determination unit that determines whether each of the multiple determined values calculated by the calculation unit is a value (error value) that is not included in the allowable range of each of the multiple items related to the processing quality of the kerf, and a modification unit that modifies the allowable range of the item so that it includes the determined value determined to be an error value by the determination unit.

In this method, the above-mentioned holding step (S1), forming step (S2), imaging step (S3), calculation step (S7), determination step (S8), change step (S9) and update step (S12) are performed in this order in the processing device 4. This makes it possible to properly perform the kerf check in the processing device 4.

In the present invention, the operator of the processing device 4 may decide whether or not to change the kerf check conditions. FIG. 10 is a flow chart that shows a schematic of part of the operation flow of the processing device 4 in such a case. In this operation flow, the CPU of the control unit 80 of the processing device 4 decides whether or not each of the multiple judged values calculated in the kerf check step (S4) is within a preset allowable range (whether or not it complies with the kerf check conditions).

If at least one of the judged values does not meet the kerf check condition (an error has occurred) (S5: YES), the operator of the processing device 4 judges whether the kerf included in the kerf image actually meets the required kerf processing quality. In other words, the operator visually checks the kerf image to see whether the kerf processing quality is abnormal.

As a result, if the operator confirms that there is no abnormality in the kerf processing quality (S13: NO), the CPU of the control unit 80 transmits an electrical signal corresponding to the image of the kerf used in the kerf check and an electrical signal corresponding to the kerf check conditions to the computer 2 in response to the operator's operation of the touch panel 76 (transmission step: S6).

In this case, the user of the computer 2 does not need to determine whether or not to apply the kerf check conditions changed in the computer 2 to the processing device 4. In other words, step (S10) shown in FIG. 8 is unnecessary.

In the present invention, the operator of the processing device 4 may set the kerf check conditions according to the image of the selected kerf. FIG. 11 is a flow chart that shows a schematic of a part of the operation flow of the processing device 4 in such a case. In this operation flow, the operator uses the image of the kerf formed in the imaging step (S3) to check whether the formed kerf satisfies the desired processing quality.

If the operator confirms that the kerf meets the desired processing quality (S14: YES), the CPU of the control unit 80 transmits an electrical signal corresponding to the image of the kerf used in the kerf check and an electrical signal corresponding to the kerf check conditions to the computer 2 in response to the operator's operation of the touch panel 76 (transmission step: S6).

In this case, it is not necessary to perform a kerf check in the processing device 4, and the user of the computer 2 does not need to determine whether or not to apply the kerf check conditions changed in the computer 2 to the processing device 4. In other words, the kerf check step (S4) shown in FIG. 5 and the step (S10) shown in FIG. 8 become unnecessary.

In the present invention, the processing device that performs the kerf check may be a laser processing device. FIG. 12 is a perspective view that shows a schematic example of a laser processing device. Note that the X-axis direction, Y-axis direction, and Z-axis direction shown in FIG. 12 correspond to the X-axis direction, Y-axis direction, and Z-axis direction shown in FIG. 4, respectively.

The laser processing device 88 shown in FIG. 12 has a base 90 that supports each component. A horizontal movement mechanism 92 is disposed on the upper surface of the base 90. The horizontal movement mechanism 92 is fixed to the upper surface of the base 90 and has a pair of guide rails 94 that extend along the Y-axis direction. A moving plate 96 is connected to the upper portion of the pair of guide rails 94 in a manner that allows it to slide along the pair of guide rails 94.

A screw shaft 98 extending along the Y-axis direction is disposed between the pair of guide rails 94. A motor 100 for rotating the screw shaft 98 is connected to one end of the screw shaft 98. A nut portion (not shown) that accommodates balls that roll on the surface of the rotating screw shaft 98 is provided on the surface of the screw shaft 98 on which a spiral groove is formed, forming a ball screw.

In other words, when the screw shaft 98 rotates, the balls circulate inside the nut portion, causing the nut portion to move along the Y-axis direction. This nut portion is also fixed to the underside of the moving plate 96. Therefore, when the screw shaft 98 is rotated by the motor 100, the moving plate 96 moves along the Y-axis direction together with the nut portion.

A pair of guide rails 102 extending along the X-axis direction are fixed to the upper surface of the movable plate 96. A movable plate 104 is connected to the upper portion of the pair of guide rails 102 in such a manner that it can slide along the pair of guide rails 102. In addition, a screw shaft 106 extending along the X-axis direction is disposed between the pair of guide rails 102.

A motor 108 for rotating the screw shaft 106 is connected to one end of the screw shaft 106. A nut portion (not shown) that accommodates balls that roll on the surface of the rotating screw shaft 106 is provided on the surface of the screw shaft 106 where a spiral groove is formed, forming a ball screw.

In other words, when the screw shaft 106 rotates, the balls circulate inside the nut portion, causing the nut portion to move along the X-axis direction. This nut portion is also fixed to the underside of the moving plate 104. Therefore, when the screw shaft 106 is rotated by the motor 108, the moving plate 104 moves along the X-axis direction together with the nut portion.

A cylindrical table base 110 is disposed on the upper surface side of the moving plate 104. A holding table 112 that holds the workpiece is disposed on the upper part of the table base 110. A rotation drive source (not shown) such as a motor is connected to the lower part of the table base 110. The force generated by this rotation drive source causes the holding table 112 to rotate around a rotation axis that is roughly parallel to the Z-axis direction.

The table base 110 and the holding table 112 are moved in the X-axis and Y-axis directions by the horizontal movement mechanism 92 described above. A portion of the upper surface of the holding table 112 is formed, for example, from a porous material, and functions as a holding surface 112a that holds the workpiece. This holding surface 112a is generally parallel to the X-axis and Y-axis directions.

The holding surface 112a is also connected to a suction source (not shown) such as a vacuum pump via a flow path (not shown) provided inside the holding table 112. When this suction source operates, negative pressure is generated on the holding surface 112a. As a result, for example, a workpiece placed on the holding surface 112a is suction-held.

A support structure 114 having a side surface generally parallel to the Y-axis direction is provided on an area on one side of the base 90 in the Y-axis direction. A vertical movement mechanism 116 is disposed on the side surface of the support structure 114. The vertical movement mechanism 116 has a pair of guide rails 118 that are fixed to the side surface of the support structure 114 and extend along the Z-axis direction.

A moving plate 120 is connected to the side of the pair of guide rails 118 that is farther from the support structure 114 so as to be able to slide along the pair of guide rails 118. A screw shaft (not shown) extending along the Z-axis direction is disposed between the pair of guide rails 118. A motor 122 for rotating the screw shaft is connected to one end of the screw shaft.

A nut portion (not shown) that accommodates balls that roll on the surface of the rotating screw shaft is provided on the surface of the screw shaft where the helical grooves are formed, forming a ball screw. That is, when the screw shaft rotates, the balls circulate inside the nut portion, causing the nut portion to move along the Z-axis direction. In addition, the nut portion is fixed to the side of the moving plate 120 that is closer to the support structure 114. Therefore, when the screw shaft is rotated by the motor 122, the moving plate 120 moves along the Z-axis direction together with the nut portion.

A support 124 is fixed to the side of the moving plate 120 that is farther from the support structure 114. The support 124 supports a part of a laser processing unit (processing unit) 126. The laser processing unit 126 includes, for example, a laser oscillator (not shown) fixed to the base 90, a cylindrical housing 128 that is supported by the support 124 and is long in the Y-axis direction, and an irradiation head 130 provided at an end of the housing 128 (the other end in the Y-axis direction).

The laser oscillator has a laser medium, such as Nd:YAG, suitable for laser oscillation, and generates a laser beam with a wavelength (e.g., 365 nm) that is absorbed by the workpiece and emits it toward the housing 128. The mode of laser oscillation performed by the laser oscillator is, for example, pulse oscillation. The housing 128 contains part of the optical system that constitutes the laser processing unit 126, such as a mirror, and guides the laser beam emitted from the laser oscillator to the irradiation head 130.

The irradiation head 130 contains another part of the optical system that constitutes the laser processing unit 126, such as a mirror and a focusing lens. The laser beam guided from the housing 128 is redirected downward by the mirror, and is focused by the focusing lens at a predetermined height on the holding table 112 side.

An imaging unit 132 is provided at a position adjacent to the irradiation head 130 in the X-axis direction. The imaging unit 132 has, for example, a light source such as an LED, an objective lens, and an imaging element such as a CCD image sensor or a CMOS image sensor.

The upper part of the base 90 is covered by a cover (not shown) that houses each component. A touch panel 134 is disposed on one side of this cover. The touch panel 134 is composed of an input device, such as a capacitive touch sensor or a resistive touch sensor, and an output device, such as a liquid crystal display or an organic EL display.

The operation of each of the components of the laser processing device 88 described above is controlled by a control unit 136 built into the laser processing device 88. The control unit 136 includes, for example, a CPU, a storage device including a main storage device (volatile memory) and an auxiliary storage device (non-volatile memory), and a communication interface. The control unit 136 and the touch panel 134 form a computer similar to the computer 2 shown in FIG. 2.

In addition, the structures and methods of the above-described embodiments can be modified as appropriate without departing from the scope of the present invention.

2: Computer 4: Processing equipment 6: Network 8: CPU (Central Processing Unit)
10: Storage device (10a: main storage device, 10b: auxiliary storage device)
12: Output device 14: Input device 16: Communication interface 18: Bus 20: Calculation unit 22: Determination unit 24: Change unit 11: Workpiece (11a: front surface, 11b: back surface)
13: Dicing tape (adhesive tape)
15: Frame 17: Workpiece unit 26: Base (26a, 26b: openings)
28: Cassette support stand 28
30: Cassette 32: Table cover 34: Dust-proof/water-proof cover 36: Holding table 38: Clamp 40: Support structure (40a, 40b: standing portion, 40c: bridge portion)
42a: First Y-axis moving mechanism 42b: Second Y-axis moving mechanism 44: Guide rail 46a, 46b: Moving plate 48a, 48b: Screw shaft 50a: Motor 52: Z-axis moving mechanism 54: Guide rail 56: Moving plate 58: Screw shaft 60: Motor 62: Cutting unit (machining unit)
64: Cutting blade 66: Imaging unit 68: Cleaning unit 70: Spinner table 72: Nozzle 74: Cover 76: Touch panel 78: Warning light (pilot lamp)
80: Control unit 82: Image 84: Image (84a: Device, 84b: Street, 84c: Calf)
86a: Item 86b: Value (value to be determined)
88: Laser processing device 90: Base 92: Horizontal movement mechanism 94: Guide rail 96: Moving plate 98: Screw shaft 100: Motor 102: Guide rail 104: Moving plate 106: Screw shaft 108: Motor 110: Table base 112: Holding table (112a: holding surface)
114: Support structure 116: Vertical movement mechanism 118: Guide rail 120: Moving plate 122: Motor 124: Support 126: Laser processing unit 128: Housing 130: Irradiation head 132: Imaging unit 134: Touch panel 136: Control unit

Claims (6)

A method for changing a tolerance range of a kerf quality that is set for performing a kerf check to check the processing quality of a kerf formed in a workpiece, the method comprising:
A calculation step of calculating a judged value of the item by using an image of the kerf formed on the workpiece by imaging the kerf;
a determining step of determining whether the determined value is an error value that is not included in the allowable range;
a change step of changing the allowable range so as to include the determined value determined to be the error value in the determination step ,
the changed acceptable range includes a value that is more deviated from the acceptable range before the change than the determined value by one minimum unit when changing the acceptable range, and does not include a value that is more deviated from the acceptable range before the change than the determined value by two minimum units . 2. The method for changing kerf quality tolerance range according to claim 1 , wherein the item is a kerf width, a chipping size, a kerf deviation amount, or a kerf recognition value. A program for causing a computer to execute a kerf quality tolerance changing method for changing a tolerance range of an item related to a kerf processing quality set for performing a kerf check to check the processing quality of a kerf formed in a workpiece, comprising:
The method for changing the kerf quality tolerance range comprises:
A calculation step of calculating a judged value of the item by using an image of the kerf formed on the workpiece by imaging the kerf;
a determining step of determining whether the determined value is an error value that is not included in the allowable range;
a change step of changing the allowable range so as to include the determined value determined to be the error value in the determination step ,
The program is characterized in that the allowable range after the change includes values that are further out of the allowable range before the change than the determined value by one minimum unit when changing the allowable range, and does not include values that are further out of the allowable range before the change than the determined value by two minimum units . A processing device comprising: a holding table for holding a workpiece; a processing unit for forming a kerf in the workpiece held on the holding table; an imaging unit for imaging the kerf to form an image of the kerf; and a control unit for changing an allowable range of an item related to the processing quality of the kerf, which is set for performing a kerf check to confirm the processing quality of the kerf formed in the workpiece,
The control unit
a calculation unit that calculates a judged value of the item by using the image of the kerf;
a determination unit that determines whether the determined value is an error value that is not included in the allowable range;
a change unit that changes the allowable range so as to include the determined value that the determination unit has determined to be the error value ,
A processing device characterized in that the allowable range after the change includes values that are further out of the allowable range before the change than the determined value by one minimum unit when changing the allowable range, and does not include values that are further out of the allowable range before the change than the determined value by two minimum units . The processing unit is a cutting unit having an annular cutting blade,
5. The processing device of claim 4 , wherein the kerf is formed by the cutting blade. The processing unit is a laser processing unit capable of irradiating a laser beam onto the workpiece,
5. The processing apparatus according to claim 4 , wherein the kerf is formed by irradiating the workpiece with the laser beam from the laser processing unit.

Images