TW202221777A - Determination method of dicing device and dicing device that prevents the situation that dicing is still started even when a predetermined discing line is set mistakenly - Google Patents

Abstract

Provided is a novel technical solution that prevents the following situation: dicing being still started even when a predetermined dicing line is set in a mistaken way. The solution is that a determination method of a dicing device is set to allow a dicing device to determine whether or not starting dicing is appropriate. The dicing device comprises: a holding bench that holds a wafer workpiece in a rotatable manner; a camera unit that performs photographing of the wafer held by the holding bench; a dicing unit (laser beam irradiation unit) that performs dicing of the wafer held by the holding bench; a movement mechanism (Y-axis movement mechanism and X-axis movement mechanism) that causes the dicing unit and the holding bench to move relative to each other in a processing feeding direction and to move relative to each other in an indexing feeding direction orthogonal to the processing feeding direction; and a controller that at least controls the camera unit, the dicing unit and the movement mechanism. The determination method of the dicing device has the following steps: a calibration step that is based on the photographic image obtained by the camera unit to set a predetermined dicing line parallel to the processing feeding direction and to perform alignment of the dicing unit with the predetermined dicing line; and a determination step in which after the calibration step is performed, the controller controls the movement mechanism and the camera unit to cause the holding bench on which the wafer is held to move relative to the camera unit in the processing feeding direction, while the camera unit is operated to photograph a front surface of the wafer to form a photographic image used in the determination, and determines starting of dicing is appropriate according to the photographic image.

Description

Determination method of cutting device and cutting device

The present invention relates to an invention of a dicing device used to individualize a plate-shaped workpiece such as a semiconductor wafer into a wafer, and more specifically, to a method for determining whether or not a planned dicing line has been set correctly. Measure to judge.

Conventionally, in a semiconductor device manufacturing process, a plurality of devices are formed on a semiconductor wafer, and the wafer is diced (divided) into individual semiconductor device wafers. In this dicing, a dicing process is performed along a dicing line (dicing line) set in a semiconductor wafer, and a dicing device such as a cutting device or a laser processing device is widely used.

The cutting device is a device including a cutting unit having a cutting blade that rotates at high speed, and performs a cutting process that forms a cutting groove along a line to be cut. The laser processing apparatus is an apparatus including a dicing unit having a laser oscillator for generating a laser beam and a condenser lens for condensing the laser beam on a semiconductor wafer, and performing cutting along a line to be cut For laser processing such as forming a laser processing groove or forming a modified layer inside a semiconductor wafer.

At the time of processing by these dicing apparatuses, the following steps are performed: the characteristic main pattern of the device existing in the semiconductor wafer to be processed is registered in the dicing apparatus as a target pattern in advance, or the dicing apparatus is Register processing conditions. During dicing, the semiconductor wafer is photographed by the imaging unit installed in the dicing device, and the main pattern included in the photographed image is matched with the pre-registered target pattern, and the dicing that becomes the dicing processing position is specified. scheduled line. Next, so-called automatic calibration for adjusting the positions of the dicing unit and the semiconductor wafer is performed so that the planned dicing line and the position of the processing point are matched. This automatic calibration is performed automatically by the control device of the cutting device. prior art literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2019-050258

The problem to be solved by the invention

However, depending on the type of wafer, pattern accuracy, adhesion of contamination or local damage to the surface, etc., automatic calibration may not be obtained. In this case, manual calibration of setting the cut line by the operator's operation is performed.

Specifically, one end side of the wafer is firstly photographed, and the operator selects the edge of the scribe line (eg, the upper side edge (which may also be the pattern on the device)) that appears between the devices in the photographed images. Next, the holding table holding the wafer is moved a predetermined distance in the X-axis direction by automatic control by the device, and the other end side of the wafer is photographed, and the operator selects the dicing line that appears in the photographed image. the edge of. Next, by the automatic control of the apparatus, the θ alignment is performed by rotating the holding table so that the imaginary line connecting the two points designated by the operator becomes parallel to the X-axis direction.

After aligning the above θ to make the cutting lane parallel to the X-axis direction (processing feed direction), the operator can select any cutting lane from a plurality of cutting lanes, and the center of the selected cutting lane can be adjusted. location is specified. The position of the center of the cutting lane thus designated becomes the planned cutting line that can be cut by the cutting blade. After that, the operator will select the cutting line to be processed initially as the "start processing line", and start processing from the start processing line.

In the manual calibration as described above, there are cases in which the planned cutting line cannot be set correctly due to the operator's proficiency. For example, in the case where the direction of the scribe line and the X-axis direction (processing feed direction) of the wafer that has been set on the holding table are not parallel, there may be the following situation: The captured image at the separated position Shoot into other cutting roads respectively. In addition, when two points of other dicing lines are connected, an imaginary line transverse to the device is set, and θ alignment is performed according to the imaginary line, or a planned dicing line is set. .

In addition, in automatic calibration, for example, when a pattern different from the target pattern is matched, or the wafer is placed in a state where the angle is deviated, a target pattern corresponding to another scribe line is detected. In such a case, an erroneous cut line may be detected.

In view of the above, the present invention proposes a novel technical solution for preventing a situation in which cutting is started even when a predetermined cutting line has been set by mistake. means of solving problems

The problem to be solved by the present invention is as described above, and next, means for solving the problem will be described.

According to an aspect of the present invention, a method for determining a cutting device is provided, wherein the cutting device is used to determine whether it is appropriate to start cutting, and the cutting device includes: Keep the worktable and keep the workpiece to rotate freely; The photographing unit is used to photograph the processed objects held by the holding table; The cutting unit cuts the workpiece held by the holding table; a moving mechanism for relatively moving the cutting unit and the holding table in the machining feed direction and in the indexing feed direction orthogonal to the machining feed direction; and a controller, at least controlling the shooting unit, the cutting unit and the moving mechanism, The determination method of the aforementioned cutting device has the following steps: a calibration step of setting a planned cutting line parallel to the machining feed direction according to the photographed image obtained by the photographing unit, and aligning the cutting unit and the planned cutting line; and In the determination step, after the calibration step is carried out, the controller controls the moving mechanism and the photographing unit to photograph the front surface of the workpiece with the photographing unit while moving the holding table holding the workpiece relative to the photographing unit in the processing feed direction. to form a photographed image for determination, and based on the photographed image, it is determined whether it is appropriate to start cutting.

Also, according to an aspect of the present invention, it is set that the cutting device further has a warning sending unit for sending warnings, In addition, there is a warning sending step in which the controller sends a warning by the warning sending unit when it is judged as inappropriate in the judging step.

Furthermore, according to one aspect of the present invention, there is provided a processing step of causing the holding table to be in the processing feed direction relative to the cutting unit when it is determined that the start of cutting is appropriate in the determination step. Relatively move, and perform cutting processing on the line to be cut.

Also, according to one aspect of the present invention, a cutting device is provided, and the aforementioned cutting device is provided with: Keep the worktable and keep the workpiece to rotate freely; The photographing unit is used to photograph the processed objects held by the holding table; The cutting unit cuts the workpiece held by the holding table; a moving mechanism for relatively moving the cutting unit and the holding table in the machining feed direction and in the indexing feed direction orthogonal to the machining feed direction; and a controller, at least controlling the shooting unit, the cutting unit and the moving mechanism, The aforementioned cutting device may implement the following steps: a calibration step of setting a planned cutting line parallel to the machining feed direction according to the photographed image obtained by the photographing unit, and aligning the cutting unit and the planned cutting line; and In the determination step, after the calibration step is carried out, the controller controls the moving mechanism and the photographing unit to photograph the front surface of the workpiece with the photographing unit while moving the holding table holding the workpiece relative to the photographing unit in the processing feed direction. to form a photographed image for determination, and based on the photographed image, it is determined whether it is appropriate to start cutting. Invention effect

According to one aspect of the present invention, when it is determined that it is not appropriate to start cutting, it is possible to detect that the planned cutting line registered by the operator's manual operation is inappropriate, and it is possible to prevent the cutting The situation at the beginning of the process to prevent the occurrence of bad conditions that cause damage to the location of the device.

Also, according to an aspect of the present invention, an operator can recognize the occurrence of an abnormality by sending a warning.

Furthermore, according to one aspect of the present invention, processing is performed only when it is determined that the start of cutting is appropriate, and it is possible to prevent a situation in which the planned cutting line registered by the operator's manual operation is inappropriate. still start cutting.

Form for carrying out the invention

Hereinafter, an embodiment of one aspect of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing a configuration example of a laser processing apparatus 2 as a dicing apparatus. Furthermore, in the following description, a laser processing apparatus including a laser beam irradiation unit is used as an example of a cutting device, but as a cutting device, a cutting unit may be provided instead of the laser beam irradiation unit. In the cutting device, the cutting unit has a cutting blade that rotates at a high speed and a main shaft that rotates the cutting blade.

As shown in FIG. 1, the laser processing apparatus 2 is provided with the base 4 which supports each structure. The base 4 includes a rectangular parallelepiped base 6 and a wall 8 extending upward from the rear end of the base 6 . On the upper surface of the base portion 6, a holding table 10 for sucking and holding the wafer (object to be processed) 11 via the tape 15 is arranged. The holding table 10 is moved in the X-axis and Y-axis directions by a moving mechanism constituted by the Y-axis moving mechanism 16 and the X-axis moving mechanism 26 .

A Y-axis moving mechanism 16 that moves the holding table 10 in the Y-axis direction (index feed direction) is provided below the holding table 10 . The Y-axis moving mechanism 16 includes one pair of Y-axis guide rails 18 fixed to the upper surface of the base 6 and parallel to the Y-axis direction.

On the Y-axis guide rail 18, a Y-axis moving table 20 is slidably provided. A nut portion (not shown) is provided on the back side (lower surface side) of the Y-axis moving table 20 , and the Y-axis balls parallel to the Y-axis guide rail 18 are rotatably coupled to the nut portion. Screw 22.

A Y-axis pulse motor 24 is connected to one end of the Y-axis ball screw 22 . By rotating the Y-axis ball screw 22 by the Y-axis pulse motor 24 , the Y-axis moving table 20 moves in the Y-axis direction along the Y-axis guide rail 18 .

The front side (upper surface side) of the Y-axis moving table 20 is provided with an X-axis moving mechanism 26 that moves the holding table 10 in the X-axis direction (processing feed direction) orthogonal to the Y-axis direction. The X-axis moving mechanism 26 includes one pair of X-axis guide rails 28 fixed to the upper surface of the Y-axis moving table 20 and parallel to the X-axis direction.

On the X-axis guide rail 28, an X-axis moving table 30 is slidably provided. A nut portion (not shown) is provided on the back side (lower surface side) of the X-axis moving table 30 , and the X-axis balls parallel to the X-axis guide rail 28 are rotatably coupled to the nut portion. Screw 32.

An X-axis pulse motor 34 is connected to one end of the X-axis ball screw 32 . When the X-axis ball screw 32 is rotated by the X-axis pulse motor 34 , the X-axis moving table 30 moves in the X-axis direction along the X-axis guide rail 28 .

A support table 36 is provided on the front side (upper surface side) of the X-axis moving table 30 . The holding table 10 is arranged above the support table 36 . The holding table 10 is connected to a rotary drive source (not shown) provided below, and rotates around the Z axis. Four jigs 38 are provided around the holding table 10 to clamp and fix the ring-shaped frame 17 supporting the wafer 11 from four directions.

The front surface of the holding table 10 is configured as a holding surface 10 a for attracting and holding the wafers 11 of the wafer unit 19 . On the holding surface 10a, a negative pressure of a suction source (not shown) acts through a flow path (not shown) formed in the inside of the holding table 10 to generate a suction force for sucking the tape 15.

A support arm 40 extending forward is provided on the upper front surface of the wall portion 8 , and the processing head 12 a of the laser beam irradiation unit 12 is provided at the front end of the support arm 40 . The laser beam irradiating unit 12 is constituted by a laser oscillator (not shown), and the processing head 12a is constituted by a condensing lens (not shown), which allows the laser beam emitted from the laser oscillator to The wafer 11 that has been held by the holding table 10 is condensed.

In the laser beam irradiation unit 12, an imaging unit 13 is provided on the side of the processing head 12a. With this imaging unit 13 , the planned dicing lines and the like on the front surface of the wafer 11 can be imaged. The captured image can be conveniently displayed on the monitor 200 by the controller 100 .

The monitor 200 is constituted by a touch panel, and is constituted so that operation input by an operator can be performed. Furthermore, the input device for operation input and the monitor 200 may be provided separately.

During the laser processing, the holding table 10 can be positioned below the processing head 12a of the laser beam irradiation unit 12 by fully automatic control based on the controller 100 or manual control based on an operator's operation. After appropriately calibrated according to the image captured by the capturing unit 13, the laser beam is irradiated from the processing head 12a, and the holding table 10 is processed and fed to perform laser processing.

On the upper front surface of the wall portion 8, a transfer device 60 for transferring the wafer unit 19 on the holding table 10 to the rotary table 52 of the cleaning device 50 is provided on the side of the support arm 40.

The transfer device 60 includes a holding arm 61 having a plurality of suction portions 61a for sucking and holding the upper surface of the frame 17 of the wafer unit 19, a lifting portion 62, a horizontal moving portion 63, and an X-axis direction moving mechanism 64, The elevating part 62 moves the holding arm up and down, the horizontal moving part 63 is connected to the elevating part 62 and moves horizontally in the X-axis direction, and the X-axis direction moving mechanism 64 moves the horizontal moving part 63 .

The X-axis direction moving mechanism 64 includes a pair of X-axis guide rails 64a, an X-axis ball screw 65, and an X-axis pulse motor 66. The pair of X-axis guide rails 64a are provided on the front surface of the wall portion 8 in the horizontal direction. The X-axis The ball screw 65 is arranged between the X-axis guide rails 64 a, and the aforementioned X-axis pulse motor 66 is provided at one end of the X-axis ball screw 65 .

The X-axis ball screw 65 is inserted into a nut part (not shown) provided in the horizontal moving part 63, and when the X-axis ball screw 65 is rotated by the X-axis pulse motor 66, the horizontal moving part 63 follows the X-axis guide rail. 64a moves in the X-axis direction, and the holding arm 61 also moves in the X-axis direction along with this.

2 is a diagram showing an example of a wafer 11 as a workpiece, and is formed by attaching a metal ring-shaped frame 17 to the tape 15 so as to surround the wafer 11 attached to the tape 15 . The wafer 11 , the tape 15 and the frame 17 are integrated into the wafer unit 19 .

The wafer 11 is designed with scribe lines S extending in the first direction F1 and the second direction F2 orthogonal to each other and arranged in a lattice shape, and the device D can be formed in the area defined by each scribe line S.

Through automatic calibration or manual calibration described later, a dicing line can be set in the scribe line, and laser processing can be performed along the dicing line L, and then individualized into device wafers by dividing. In addition, in this specification, the term "setting of the intended cutting line" includes either detection of the intended cutting line by automatic calibration or setting of the intended cutting line by manual calibration.

As shown in FIG. 2 and FIG. 3 , there are various patterns constituting each device D on the wafer, and before the dicing process is performed, the operator will select the characteristic main pattern Pk on the wafer, and put the pattern Pk on the wafer. The main pattern Pk is registered to the controller 100 as the target pattern Pt.

It is assumed that the main pattern Pk exists at the same position in each device D, and the imaginary line K formed by connecting the main patterns Pk formed on the devices D arranged in the same row becomes the line to cut L parallel.

When the target pattern Pt is registered, the reference distance Lm from the main pattern Pk to the line L to be cut is also registered. Various attribute information of the wafer 11 such as the adjacent planned dicing line L, the indexing moving distance Ln between the dicing lanes S, and the diameter of the wafer 11 can be registered in the controller 100 as processing conditions before processing.

Automatic calibration can be performed by referring to the target pattern Pt registered to the controller 100 .

Automatic calibration is set to be performed as follows. The controller 100 detects by moving and holding the table 10 and photographing a plurality of places on the wafer 11 (two places at both ends of the wafer 11 in the X-axis direction in the example of FIG. 3 ) with the photographing unit 13 . Cut the predetermined line L. Specifically, the first shot image G1 is shot, and by pattern matching, the main pattern Pk that matches the target pattern Pt is detected from the shot image G1, and the main pattern Pk of the main pattern Pk is detected. Coordinate position. Next, the holding table 10 is moved in the machining feed direction (X-axis direction), the second captured image G2 is captured, and the coordinate position of the main pattern Pk in the captured image G2 is similarly detected.

The controller 100 detects an imaginary line K connecting the coordinate positions of the detected two main patterns Pk. Then, the position deviated from the virtual line K by the reference distance Lm is detected as the line to cut L. Here, when the direction of the imaginary line K and the machining feed direction (X-axis direction) deviate, the angle adjustment for rotating the holding table 10 is appropriately performed, and the adjustment angle is registered (theta alignment operation).

Next, the holding table 10 is rotated by 90 degrees, and the line to cut L extending in the second direction F2 of the wafer 11 is similarly detected. Here, also in the second direction F2, when the direction of the imaginary line is deviated from the machining feed direction (X-axis direction), the angle adjustment of the rotation holding table 10 is appropriately performed, and the adjustment angle (theta alignment operation) is registered. ).

Next, the position of the planned cutting line on the software is aligned with the position of the laser beam irradiation unit 12 , so that the detected planned cutting line can be laser processed by the laser beam irradiation unit 12 . In this way, the automatic calibration for aligning the planned cutting line with the laser processing position is completed.

In the processing after the automatic alignment is completed, for example, the line L2 to be cut extending in the second direction F2 on the outermost side of the wafer 11 is positioned relative to the laser beam irradiation unit 12 to start processing, and the indexing progress is performed. Then, processing is performed for all the lines to be cut in the second direction F2. Next, similarly, after rotating the wafer by 90 degrees, processing is started from the line L1 to be cut extending in the first direction F1 at the outermost side of the wafer 11, and the index feed is performed for the first direction F1. The processing of all the scheduled cutting lines.

Here, in FIG. 3 , when the wafer 11 is dirty or the pattern is partially damaged, the following problem occurs: the main pattern matching the target pattern Pt cannot be detected. Pk, and the line L to be cut cannot be detected. In such a case, the processing of the wafer 11 is not started, but the wafer 11 is unloaded once, and is calibrated in the manual calibration mode at another timing, and the processing is carried out. In addition, for example, when the cutting insert is broken during processing and the processing is stopped, after the operator replaces the cutting insert, the processing of the unprocessed area of the wafer is performed. At the time of this processing, calibration based on the manual calibration mode can also be performed.

Manual calibration is performed as follows. When the manual calibration mode is selected and started to execute, as shown in FIG. 3 , a captured image G1 of a predetermined area on the wafer 11 will be captured by the controller 100 , and the operator will, for example, appear in the captured image G1 The edge on the upper side of the scribe line S is selected as the first point P1. When the first point P1 is selected, the controller 100 moves the wafer 11 (holding table 10 ) by a predetermined distance in the processing feed direction, that is, the X-axis direction, and captures the second captured image G2. The operator selects, for example, the edge on the upper side of the scribe line S appearing in the captured image G2 as the second point P2.

The controller 100 connects the two points P1 and P2 selected by the operator to set the imaginary line K1, and when the imaginary line K1 and the X-axis direction do not match, the controller 100 rotates the wafer 11 (holds the table 10) to The θ alignment is performed so that the imaginary line K1 and the X-axis direction are aligned. After the θ alignment has been performed, the controller 100 sets a position away from the virtual line K1 corresponding to the reference distance Lk registered in advance as the planned cutting line. In this way, the predetermined cutting line can be set by the controller 100 according to the operation of the operator.

Here, in FIG. 3 , since the operator's proficiency is low, and when the second point P2 should be selected in the captured image G2 originally, when another position P3 is selected, it will be set and cut. The imaginary line Kz of the track S is not parallel, which leads to the situation that the wrong planned cutting line is set.

In addition, as shown in FIG. 4 , when the wafer 11 is set in a state where the scribe line S of the wafer 11 is not parallel to the X-axis direction, which is the processing feed direction, and is deviated by an angle θ, there may be a possibility that each photographed image Like the case where G1, G2 contain additional rows of scribe lines St1, St2. Furthermore, when the imaginary line K2 is set based on the scribe lines St1 and St2 appearing in the respective captured images G1 and G2, the planned cutting line L6 is set at a place where the scribe lines do not exist originally.

As shown in FIG. 3 and FIG. 4 , when an incorrect dicing line is set, the device D is processed and damaged. In order to prevent such inconveniences, in the present invention, the detection method and the determination method of the line to be cut are carried out as follows.

Hereinafter, the detection method and the determination method of the line to cut according to the present invention will be described. [Example 1]

Example 1 is an example in which manual calibration and detection or determination of the planned dicing lines are carried out for the unprocessed wafer and the main pattern is not detected. FIG. 5 is a flowchart showing the flow of each step in the case of carrying out Embodiment 1. FIG.

<Calibration procedure> The following steps are as follows: In FIG. 3, a planned cutting line L parallel to the machining feed direction (X-axis direction) is set by manual calibration, and the cutting unit (laser beam irradiation unit 12) and the planned cutting line are set. Alignment is performed (step S1 in FIG. 5 ).

Specifically, as shown in FIG. 6(A), for the first direction F1 of the wafer 11, as described above, the controller sets and processes the feed direction based on the two points P1 and P2 selected by the operator (X-axis direction) parallel lines L to be cut.

In addition, the controller aligns the position of the planned cutting line on the software with the position of the laser beam irradiation unit 12 , so that the laser beam irradiation unit 12 can perform laser processing on the set predetermined cutting line.

As described above, the setting of the planned cutting line is performed, and the calibration for aligning the planned cutting line with the laser processing position is carried out.

<Judgment procedure> It is the following steps: as shown in FIG. 6(D), FIG. 7(A)(B) and FIG. 8(A), after the calibration step is performed, the wafer 11 (holding table 10 ) is positioned relative to the imaging unit 13 The front surface of the wafer 11 is photographed while moving in the processing feed direction to form a plurality of photographed images G1, G2... for determination, and it is determined whether it is appropriate to start dicing based on the formed photographed images G1, G2.... In the present embodiment, first, the step of determining the line to cut extending in the first direction F1 is performed (step S2 in FIG. 5 ).

Specifically, the wafer 11 (holding table 10 ) is moved in the Y-axis direction, and the position in the Y-axis direction of the imaging unit 13 and the position of the captured images G1 , G2 . . . for imaging determination are made. After the positions of the imaging line L3 in the Y-axis direction are aligned, the wafer 11 (holding table 10 ) is moved in the X-axis direction (processing feed direction) to acquire captured images G1 , G2 . . .

Furthermore, the position in the Y-axis direction of the imaging line L3 can be set as the location to be cut in an arbitrary manner, for example, by the operator, or the controller can be automatically set according to the attribute information of the wafer 11. The mode is set, or is set to be deviated by a predetermined number of lines from the planned cutting line at which the cutting is started. In the example shown in FIG. 6(D) , an example in which the captured images G1 , G2 . . . for determination are captured along the imaging line L3 is shown.

Furthermore, as shown in FIG. 7(B) , the captured images G1 , G2 . . . for determination may be configured to capture only a plurality of positions at intervals in addition to capturing all the positions of the line L3 for capturing images. , or take just one shot.

Based on the above-mentioned captured images G1 , G2 . . . for determination, the controller determines whether it is appropriate to start cutting. When it is determined that it is not appropriate to start dicing, it is possible to detect that the set planned dicing line is not appropriate, and prevent the dicing from being started, thereby preventing the location of the device from being processed due to the The occurrence of adverse conditions of its damage.

As the determination contents, for example, the following contents can be considered, and in addition to the method of determining all of them, any one of them may be determined.

<Judgment content 1> It is the following judgment: whether the set line to cut is parallel to the X-axis direction.

For example, as shown in FIG. 4 , when the wafer 11 is tilted and the line to cut is set by mistake in the tilted state, it will be displayed for the judgment as shown in FIG. 8(A) . The cut line of the captured image is also inclined.

In the implementation of this determination content 1, first, the determination line L4 is set by the controller 100 . Specifically, the controller 100 detects the margin (edge) Sf of the scribe line S by image processing, and connects the detected margins Sf to form the determination line L4. Furthermore, it can also be set as follows: the controller 100 detects the main pattern Pk and the target pattern Pt in each captured image by pattern matching ( FIG. 4 ), and connects with each main pattern Pk by connecting The determination line L4 is set at each position corresponding to the reference distance Lm.

In addition, when the determination line L4 deviates from the machining feed direction (X-axis direction) by a predetermined angle or more, the controller 100 determines that it is inappropriate to start cutting. In the example of FIG. 8(A) , it is determined to be inappropriate because the deviation is by an angle θ.

On the other hand, as shown in FIG. 8(B) , when the direction of the determination line L4 coincides with the machining feed direction (X-axis direction), it is determined that it is appropriate to start cutting.

<Judgment content 2> As shown in FIG. 9(A), it is determined whether or not the set line to cut is the center in the Y-axis direction of the dicing lane.

In the implementation of the determination content 2, the determination line L5 is set by the controller 100 . Specifically, the controller detects the margin Sf of the device D adjacent in the Y direction of the scribe line by image processing, and sets a line passing through the middle position of the detected margin Sf in the Y-axis direction as the judgment Use line L5. Then, it is detected whether or not there is a deviation between this determination line L5 and the Y-axis direction position (planning position) of the fine reticle H set in the imaging unit 13 .

The imaging unit 13 is constituted by a microscope, a reticle H is set at the center of an image captured by the microscope, and a position corresponding to the position of the reticle H in the Y-axis direction can be processed. In addition, in the state where the above-mentioned calibration step has been completed, as long as there is no problem in the calibration, the position corresponding to the position in the Y-axis direction of the fine reticle H can be processed.

In addition, the controller 100 determines that it is inappropriate to start cutting, for example, when the above-mentioned determination line L5 deviates from the position of the fine reticle H by a predetermined distance or more. In the example of FIG. 9(A) , since the offset amount ΔY is greater than or equal to the predetermined distance, it is determined to be inappropriate.

On the other hand, as shown in FIG.9(B), when the position of the determination line L5 and the thin reticle H coincides, it is determined that it is appropriate to start cutting. In addition, in the example of FIG. 9(B), the case where the determination line L5 and the thin reticle H coincide is shown.

Furthermore, in (A) and (B) of FIG. 9 , although the line L5 for determination is set at the intermediate position of the device D adjacent in the Y-axis direction of the scribe line S, and the line L5 for determination and the fine mark are set. The relative positions of the lines H have been compared, but the determination can also be made by the following method: when the device D exists only on one side in the Y-axis direction of the scribe line S, it is detected that the Whether there is a thin reticle H at a position where the sample Pk is separated from the reference distance Lm.

<Judgment content 3> As shown in FIG. 9(C), it is determined whether or not all the lines to be cut have been processed.

If the processed wire is cut, it may cause a defect. For example, in a cutting device in which a cutting groove is formed by a cutting insert, if the previously formed cutting groove V is further processed, the cutting insert may be damaged. In such a case, it is not appropriate to perform cutting with respect to the planned cutting line appearing in the captured image.

In the example of FIG. 9(C) , the cutting groove V is captured in the image for determination, and the controller 100 recognizes the cutting groove V through image analysis, and determines that it is inappropriate to start cutting. On the other hand, when the cutting groove V is not confirmed, the determination content 3 is determined to be appropriate.

<Warning procedure> In the above determination step, when it has been determined that it is inappropriate to start cutting, a warning is issued by the warning transmitting means (step S3 in FIG. 5 ).

Specifically, in the configuration example shown in FIG. 1 , the controller 100 transmits a warning signal including display, sound, light, etc. from warning transmitting means such as the monitor 200 , the speaker 201 , and the warning lamp 202 . warn.

While implementing this warning step, the controller 100 will interrupt the start of cutting. Furthermore, this warning step can also be omitted, and the cutting interruption will be started without sending the warning.

By sending a warning as described above, it is possible for the operator to recognize the occurrence of an abnormality.

<Processing steps> It is the following step: in the above determination step, when it is determined that it is appropriate to start cutting, as shown in FIG. It moves relatively in the processing feed direction, and irradiates the laser beam B to cut the line to cut (step S4 in FIG. 5 ).

In the previous stage of the processing step, by performing the determination of each of the above-mentioned determination contents, the probability of occurrence of a defect in the case where the cutting process has been started can be reduced.

Moreover, processing is performed only when it is judged that it is appropriate to start cutting, and it is possible to prevent the situation where cutting is started even when the set line to cut is not appropriate.

In this processing step, as shown in FIG. 6(A), processing is performed on the line to cut extending in the first direction F1. After the processing step has been completed for the dicing line extending in the first direction F1, the wafer is rotated by 90 degrees (step S5 in FIG. 5 ), and the calibration step is performed in the same manner for the second direction F2 (step S6 in FIG. 5 ). ), a determination step (step S7 in FIG. 5 ), a warning step (step S8 in FIG. 5 ), and a processing step (step S9 in FIG. 5 ).

Furthermore, in the determination step for the second direction F2, since the cutting grooves formed in the first direction F1 are captured in the captured image for determination, there is a possibility of being erroneously determined in the determination content 3 above. Therefore, it is preferable to perform image processing of masking the cutting groove so as not to display the captured image for determination.

In addition, after the determination step is performed on the planned dicing line extending in the first direction F1, the wafer is rotated by 90 degrees, and the calibration step, the determination step, and the warning may be performed on the planned dicing line extending in the second direction F2. After the step, the processing step is performed for the line to cut extending in the second direction F2, and then the wafer is rotated by 90 degrees to perform the processing step for the line to be cut extending in the first direction F1.

In addition, after performing the calibration step based on manual calibration with respect to the first direction F1 of the wafer, rotate the wafer by 90 degrees, and perform the calibration step based on manual calibration with respect to the second direction F2 of the wafer, and then , after the determination step, the warning step, and the processing step are performed with respect to the second direction F2, the wafer is rotated by 90 degrees, and the determination step, the warning step, and the processing step are performed with respect to the first direction F1.

In this case, in the determination step for the first direction F1, since the cutting grooves formed in the second direction F2 are captured in the captured image for determination, there is a possibility of being erroneously determined in the determination content 3 above. Therefore, it is preferable to perform image processing of masking the cutting groove so as not to display the captured image for determination. [Example 2]

In the case of performing automatic calibration, the same determination as above can be performed. FIG. 11 is a flowchart showing the flow of each step in the case of carrying out Embodiment 2. FIG.

First, in the same way as the above-mentioned calibration procedure, a line to be cut parallel to the machining feed direction (X-axis direction) is set by automatic calibration, and the cutting unit (the laser beam irradiation unit 12 ) and the line to be cut are aligned. bit.

After performing the calibration step, the determination step, and the warning step in the first direction F1 of the wafer ((A) of FIG. 6 ), the wafer is rotated by 90 degrees, and the second direction F2 of the wafer (the part of FIG. 6 ) is rotated by 90 degrees. (B)) The calibration step, the judgment step, and the warning step are performed in the same manner.

In the case of performing without warning, after directly performing the processing step with respect to the second direction F2, the wafer is rotated by 90 degrees again, and the processing step is performed with respect to the first direction F1.

In addition to the above, it is also possible to perform the calibration step, the determination step, the warning step, and the processing step based on automatic calibration with respect to the first direction F1 of the wafer, and then rotate the wafer by 90 degrees. In the second direction F2, a calibration step, a judgment step, a warning step, and a processing step by automatic calibration are performed.

In this case, in the determination step for the second direction F2, since the cutting groove formed in the first direction F1 is captured in the captured image for determination, there is a possibility of being erroneously determined in the determination content 3 above. Therefore, it is preferable to perform image processing of masking the cutting groove so as not to display the captured image for determination.

In addition, after the calibration step based on automatic calibration is performed for the first direction F1 of the wafer, the wafer is rotated by 90 degrees, and the calibration step based on auto calibration is performed for the second direction F2 of the wafer, and then Then, after the determination step, the warning step, and the processing step are performed with respect to the second direction F2, the wafer is rotated by 90 degrees, and the determination step, the warning step, and the processing step are performed with respect to the first direction F1.

In this case, in the determination step for the first direction F1, since the cutting grooves formed in the second direction F2 are captured in the captured image for determination, there is a possibility of being erroneously determined in the determination content 3 above. Therefore, it is preferable to perform image processing of masking the cutting groove so as not to display the captured image for determination.

2: Laser processing device 4: Abutment 6: Base 8: Wall 10: Keep the workbench 10a: Keep Faces 11: Wafer 12: Laser beam irradiation unit 12a: Processing head 13: Shooting unit 15: Tape 16: Y-axis moving mechanism 17: Frames 18: Y-axis guide 19: Wafer unit 20: Y-axis moving table 22: Y-axis ball screw 24: Y-axis pulse motor 26: X-axis moving mechanism 28,64a: X-axis guide 30: X-axis moving table 32,65: X-axis ball screw 34,66: X-axis pulse motor 36: Support table 38: Fixtures 40: Support arm 50: Washing device 52: Rotary table 60: Conveying device 61: Holding Arm 61a: Department of Attraction 62: Lifting part 63: Horizontal moving part 64: X-axis direction moving mechanism 100: Controller 200: Monitor 201: Speakers 202: Warning light B: Laser beam D: device F1: 1st direction F2: 2nd direction G1~G8: Capture images H: fine line K, K1, K2, Kz: imaginary lines L, L1, L2, L6: cut predetermined lines L3: line for shooting L4, L5: Judgment line Lk, Lm: reference distance Ln: indexing moving distance M, M1, M2: cutting path P1: Point 1 P2: point 2 P3: Other locations Pk: main pattern Pt: target pattern S, St1, St2: cutting road Sf: Marginal V: cutting groove X,Y,Z: direction θ: angle S1~S9, S11~S20: Steps ΔY: offset

FIG. 1 is a perspective view showing a configuration example of a laser processing apparatus as a dicing apparatus. FIG. 2 is a diagram showing an example of a wafer as a workpiece. FIG. 3 is a diagram illustrating calibration. FIG. 4 is a diagram illustrating a case where there is an angular deviation between the machining feed direction and the line to cut. FIG. 5 is a flowchart showing the flow of each step in the first embodiment. FIG. 6(A) is a diagram showing the setting of the line to cut extending in the first direction. (B) is a diagram showing the setting of the line to cut extending in the second direction. (C) is a diagram illustrating the situation when the calibration step is completed. (D) is a diagram explaining the situation at the time of the determination step. FIG. 7(A) is a diagram illustrating acquisition of a captured image in the determination step. (B) A diagram for explaining a photographed image for determination of photographing along the photographing line. FIG. 8(A) is a diagram illustrating the determination based on the determination line. (B) is a diagram illustrating a case where the direction of the determination line and the machining feed direction coincide. (A) of FIG. 9 is a figure which shows the case where the deviation arises between the hair line and the line for determination. (B) is a figure which shows the case where the thin reticle and the line for determination agree|coincide. (C) is a figure explaining the case where a cutting groove is imaged in a photographed image. FIG. 10 is a diagram illustrating a processing procedure. FIG. 11 is a flowchart showing the flow of each step of the second embodiment.

10: Keep the workbench

11: Wafer

100: Controller

D: device

F1: 1st direction

F2: 2nd direction

G1, G2: Capture images

K2: Imaginary line

L, L6: Cut the predetermined line

Lk: reference distance

P1: Point 1

P2: point 2

Pk: main pattern

Pt: target pattern

S, St1, St2: cutting road

X: direction

θ: angle

Claims (4)

A method for determining a cutting device, using the cutting device to determine whether it is appropriate to start cutting, the cutting device having: Keep the worktable and keep the workpiece to rotate freely; The photographing unit is used to photograph the processed object that has been held by the holding table; A cutting unit, which cuts the workpiece held by the holding table; a moving mechanism for relatively moving the cutting unit and the holding table in the machining feed direction and in the indexing feed direction orthogonal to the machining feed direction; and a controller, at least controlling the shooting unit, the cutting unit and the moving mechanism, The determination method of the aforementioned cutting device has the following steps: a calibration step of setting a planned cutting line parallel to the machining feed direction according to the photographed image obtained by the photographing unit, and aligning the cutting unit with the planned cutting line; and Determination step: After the calibration step is performed, the controller controls the moving mechanism and the photographing unit to move the holding table holding the workpiece relative to the photographing unit in the processing feed direction, while moving the holding table with the photographing unit in the processing feed direction. The photographing unit photographs the front surface of the workpiece to form a photographed image for determination, and determines whether it is appropriate to start cutting based on the photographed image. The method for determining a cutting device according to claim 1, wherein the cutting device further has a warning sending unit for sending warnings, In addition, the judgment method of the cutting device includes a warning sending step. In the warning sending step, the controller sends a warning through the warning sending unit when it is judged inappropriate in the judging step. The method for determining a cutting device according to claim 1 or 2, which includes a processing step of placing the holding table in the cutting unit relative to the cutting unit when it is determined that the start of cutting is appropriate in the determining step. The relative movement in the machining feed direction is performed, and the cutting process is performed on the line to be cut. A cutting device is provided with: Keep the worktable and keep the workpiece to rotate freely; The photographing unit is used to photograph the processed object that has been held by the holding table; A cutting unit, which cuts the workpiece held by the holding table; a moving mechanism for relatively moving the cutting unit and the holding table in a machining feed direction and in an indexing feed direction orthogonal to the machining feed direction; and a controller, at least controlling the shooting unit, the cutting unit and the moving mechanism, The aforementioned cutting device may implement the following steps: a calibration step of setting a planned cutting line parallel to the machining feed direction according to the photographed image obtained by the photographing unit, and aligning the cutting unit with the planned cutting line; and Determination step: After the calibration step is performed, the controller controls the moving mechanism and the photographing unit to move the holding table holding the workpiece relative to the photographing unit in the processing feed direction, while moving the holding table with the photographing unit in the processing feed direction. The photographing unit photographs the front surface of the workpiece to form a photographed image for determination, and determines whether it is appropriate to start cutting based on the photographed image.

Images