Processing device and processing method

Abstract

To provide a processing device for forming a processing groove to a wafer, capable of easily performing adjustment operation at a processing groove correction (a hairline correction).SOLUTION: A processing device for forming a processing groove to which a plurality of devices is segmented by a street and which divides a wafer formed on a surface into individual devices, comprises: processing means of forming the processing groove; X-shaft transferring means; Y-shaft transferring means; imaging means to which a reference line K for imaging the wafer and detecting the processing groove is set; and display means 40. In the display means: an image display part 42; a Y-shaft direction operation part 44 that makes the Y-shaft transferring means to be operated; a pair of movable lines 46a and 46b that is approached and separated to / from the reference line; a pair of processing groove recognition lines 52a and 52b that is set so as to be matched to the edges 50a and 50b of the processing groove 50 to be recognized; and an adjustment button 48 are displayed. When touching the adjustment button, the Y-shaft transferring means is operated so that the reference line is matched to the center of the processing groove, and a movable line is matched to each processing groove recognition line.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a processing apparatus that forms grooves that divide a wafer having a surface on which a plurality of devices are partitioned by streets into individual devices, and more particularly to groove correction (hairline correction). [Background technology]

[0002] Conventionally, a cutting device that cuts and dices a semiconductor wafer along streets (planned dividing lines) is known. As shown in Patent Document 1, for example, this type of cutting device is configured to include a holding means for holding a wafer, a cutting means having a rotatable cutting blade for cutting the streets of the wafer held by the holding means, an X-axis feed means for relatively feeding the holding means and the cutting means in the X-axis direction, a Y-axis feed means for relatively indexing and feeding the holding means and the cutting means in the Y-axis direction perpendicular to the X-axis direction, an imaging means on which a reference line is set for imaging the wafer held by the holding means and detecting the streets and cutting grooves, and a display means. The reference line is provided on the objective lens of a microscope provided in the imaging means and is displayed at the center of the image display unit of the display means.

[0003] In the configuration of Patent Document 1, the display means displays an image display section that displays an image captured by the imaging means, a machined groove correction button for storing the amount of deviation between the cut groove and the reference line as a correction value, an X-axis operating section that operates the X-axis feed means, a Y-axis operating section that operates the Y-axis feed means, a pair of movable wires that approach and move away from the reference line while maintaining linear symmetry about the reference line, and a movable wire operating section that moves the pair of movable wires.

[0004] When the Y-axis operating unit is operated to position the center of the cutting groove on the reference line and the distance between the pair of movable lines is positioned to the width of the cutting groove, touching the cutting groove correction button stores the movement distance of the cutting groove in the Y-axis direction as the correction value in the Y-axis direction, and the reference line and the center of the cutting groove are corrected to coincide during the indexing feed of the next street.

[0005] The process of matching the center position of the actual cut groove with the reference line (the center of the image display unit) and storing the correction value as described above is called cut groove correction (hairline correction). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-145636 A Summary of the Invention [Problem to be solved by the invention]

[0007] In the configuration of Patent Document 1, when making a correction using the cutting groove correction button, the operator must stare at the display means while activating the Y-axis operating unit to align the reference line with the center of the cutting groove, and then activate the movable line operating unit to adjust the pair of movable lines to match both edges of the cutting groove. However, this requires repeated fine adjustments using adjustment keys provided separately on a touch panel or the like, and the adjustment work takes a lot of time and effort.

[0008] In view of the above problems, the present invention proposes a new technique that makes it possible to easily perform adjustment work when correcting a processed groove (hairline correction) in a processing device that forms a processed groove in a wafer. [Means for solving the problem]

[0009] The problem to be solved by the present invention has been described above, and the means for solving this problem will now be described.

[0010] According to one aspect of the present invention, there is provided a processing apparatus for forming machined grooves that divide a wafer having a surface on which a plurality of devices are partitioned by streets into individual devices, the apparatus comprising: a holding means for holding a wafer; a processing means for forming machined grooves in the streets of the wafer held by the holding means; an X-axis feed means for relatively feeding the holding means and the processing means in the X-axis direction; a Y-axis feed means for relatively indexing and feeding the holding means and the processing means in the Y-axis direction perpendicular to the X-axis direction; an imaging means having a reference line set for imaging the wafer held by the holding means and detecting the machined grooves; and a display means. and wherein the display means displays an image display section for displaying the image captured by the imaging means, a Y-axis direction operation section for operating the Y-axis feed means, a pair of movable lines that approach and move away from the reference line while maintaining linear symmetry about the reference line, a pair of machined groove recognition lines that are set to match the edges of the machined groove recognized by image processing from within the image captured by the imaging means, and an adjustment button, and when the adjustment button is touched, the Y-axis feed means is operated to match the reference lines to the center of the machined groove, and the movable lines are matched to the machined groove recognition lines.

[0011] According to another aspect of the present invention, by touching the adjustment button, the amount of deviation between the center of the machined groove and the reference line is stored as a correction value.

[0012] According to one aspect of the present invention, the processing means is cutting means having a rotatable cutting blade, and the processing groove is a cutting groove.

[0013] According to one aspect of the present invention, there is provided a machining method in which, when machining the next unmachined street adjacent thereto, the position of the machining means in the Y-axis direction is corrected with the correction value to form a machining groove. Effect of the Invention

[0014] The present invention provides the following advantages. That is, according to one aspect of the present invention, since the correction value can be obtained by simply touching the adjustment button, the operator does not need to stare at the monitor or make repeated fine adjustments, and the adjustment work can be performed easily and in a short time. Furthermore, since the adjustment work can be completed in a short time, the throughput in processing can be improved.

[0015] Furthermore, according to one embodiment of the present invention, the deviation amount between the center position in the Y-axis direction of the machined groove obtained during the adjustment work and the reference line is stored as a correction value, so that when the next street to be machined is machined, the preset indexing feed amount can be corrected with the correction value, thereby improving the machining accuracy. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is a diagram showing an example of a wafer that is a workpiece. [Diagram 2] FIG. 13 is a diagram showing an example of a processing device. [Diagram 3] 5A to 5C are diagrams illustrating machined grooves formed by the cutting unit. [Figure 4] FIG. 4 is a diagram for explaining the contents displayed on a display unit. [Diagram 5] FIG. 11 is a diagram showing an example of a display on the display means after machining groove correction. [Figure 6] 6A to 6C are diagrams showing movement of the position of the cutting blade in the Y-axis direction by the Y-axis feed means. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an example of a wafer as a workpiece. The wafer W is configured in a disk shape, and on its surface Wa, a plurality of devices D are formed in areas defined by streets S. By forming grooves along the streets S, it is planned to divide the wafer W into chips each including the devices D.

[0018] The back surface Wb of the wafer W is attached to an adhesive tape T, and an annular frame F is attached to the adhesive tape T so as to surround the outer periphery of the wafer W. The wafer W and the annular frame F are integrated via the adhesive tape T to form a wafer unit U.

[0019] FIG. 2 is a diagram showing an example of a processing apparatus according to the present invention. The processing device 2 is configured to include a holding table 8 serving as a holding means for holding the wafer W, a cutting unit 20 serving as a processing means for forming machining grooves in the streets of the wafer W held on the holding table 8, an X-axis feed means (not shown) for relatively feeding the holding table 8 and the cutting unit 20 in the X-axis direction, a Y-axis moving mechanism 17 serving as a Y-axis feed means for relatively indexing and feeding the holding table 8 and the cutting unit 20 in the Y-axis direction perpendicular to the X-axis direction, an imaging unit 7 serving as an imaging means in which a reference line is set for imaging the wafer W held on the holding table 8 and detecting the machining grooves, and a touch panel type monitor 40 serving as a display means.

[0020] In this embodiment, the processing means of the processing device 2 is a processing means (cutting unit 20) equipped with a rotatable cutting blade, and the processed groove is a cut groove. In addition, the present invention is also applicable to a laser processing device in which the processing means is a laser processing unit and a laser processed groove is formed in a wafer.

[0021] To explain in detail below, the processing device 2 has a base 4, and a holding table 8 is disposed on the base 4 so as to be capable of reciprocating in the X-axis direction. A plurality of clamps 9 and a water cover 11 are disposed around the holding table 8, and a bellows 12 is connected between the water cover 11 and the base 4 to protect the X-axis feed means (not shown) disposed below.

[0022] The X-axis feed means (not shown) is configured, for example, with a pulse motor, a ball screw rotated by the pulse motor, and a guide rail, and feeds the holding table 8 and the cutting unit 20 relatively in the X-axis direction for processing.

[0023] The holding table 8 is configured to be rotated within a horizontal plane by a rotating means (not shown) provided below the holding table 8, so that the angle of the wafer W can be set.

[0024] On the upper surface of the base 4, there are provided a cassette placement portion 5a for placing a cassette 5 for accommodating a wafer W therein, and a cleaning device 6 for cleaning the workpiece after cutting.

[0025] The wafer unit U is stored in a cassette 5 and carried onto the holding table 8 by a transport device not shown. As will be described in detail later, the wafer unit U is cut in the cutting unit 20, transported to the cleaning device 6 and cleaned, and then carried out back into the cassette 5.

[0026] A gate-shaped column 14 is erected on the base 4, and a pair of guide rails 15 extending in the Y-axis direction, a Y-axis movement mechanism 17 consisting of a ball screw 16a and a pulse motor 16b, and a Y-axis movement block 18 are provided on the side of the column 14, and the Y-axis movement block 18 moves in the Y-axis direction along the guide rails 15 by driving the Y-axis movement mechanism 17. Such a Y-axis movement mechanism 17 constitutes a Y-axis feed means that relatively indexes and feeds the holding table 8 and the cutting unit 20 in the Y-axis direction perpendicular to the X-axis direction.

[0027] The Y-axis moving block 18 is provided with a pair of guide rails 19 extending in the Z-axis direction, a Z-axis moving mechanism 32 consisting of a ball screw 31a and a pulse motor 31b, and a Z-axis moving block 30, and the Z-axis moving block 30 is moved in the Z-axis direction along the guide rails 19 by being driven by the Z-axis moving mechanism 32. Such a Z-axis moving mechanism 32 constitutes a Z-axis moving means that positions the cutting unit 20 at a cutting height in the Z-axis direction perpendicular to the X-axis direction and the Y-axis direction.

[0028] The cutting unit 20 is attached to the Z-axis moving block 30. A spindle (not shown) is rotatably accommodated in a spindle housing 36 of the cutting unit 20, and a disk-shaped cutting blade 21 is attached to the tip of the spindle. An imaging unit 7 is disposed near the cutting unit 20, and the cutting unit 20 and the imaging unit 7 move together in the Y-axis and Z-axis directions.

[0029] The various mechanisms described above and the display of the images captured by the imaging unit 7 on the monitor 40 are controlled by a controller 10. The controller 10 is configured to have hardware such as a CPU and a memory, and software stored in the memory, and is configured to perform various controls of the processing device.

[0030] FIG. 3 is a diagram for explaining a machined groove 50 formed by the cutting unit 20, and an example of an image captured by the imaging unit 7 is displayed on the monitor 40. As shown in FIG. During processing, the position of the street S and the position of the cutting blade 21 are aligned, and the cutting blade 21 is positioned at the cutting height and rotated at high speed. Next, the wafer W (holding table 8 (FIG. 2)) is processed and fed in the X-axis direction to form a processed groove 50 along the street S. The processed groove 50 may be processed as a full-cut groove that completely divides the wafer W, or as a half-cut groove that cuts the wafer W halfway in the thickness direction.

[0031] During alignment and, more specifically, during machining groove correction, the imaging unit 7 captures an image of the surface Wa of the wafer W. The imaging unit 7 has, for example, a microscope 7a arranged facing the surface Wa of the wafer W, and a reference line K is formed by printing or the like on the objective lens or lens cover of the microscope 7a. As a result, the reference line K is displayed on the image captured by the imaging unit 7 and displayed on the monitor 40.

[0032] In the image displayed on the monitor 40, the up-down direction is the Y-axis direction of the processing device, and the left-right direction is the X-axis direction. The reference line K is displayed at the center position (center position) in the Y-axis direction (up-down direction) of the image. Note that the reference line K may be displayed as it is captured, or may be processed by software in the controller and displayed on the image as the reference line K.

[0033] Furthermore, due to the above-mentioned alignment performed before the start of machining, the reference line K is displayed at a position coinciding with the center position in the Y-axis direction of each street.

[0034] 3, the reference line K and the center position in the up-down direction of the machined groove 50 (center position in the Y-axis direction) coincide with each other, and there is no deviation in the position of the machined groove 50 with respect to the street S. In other words, the machined groove 50 is accurately machined without deviation from a predetermined position.

[0035] After machining a groove for a certain street S, the wafer W (holding table 8 (FIG. 2)) is indexed (indexed) by an indexing feed amount preset in the controller, so that the cutting blade 21 is positioned at the position of an adjacent unmachined street S. Then, in the same manner as above, the wafer W (holding table 8 (FIG. 2)) is fed for machining in the X-axis direction, so that a groove 50 is formed along the unmachined street S.

[0036] The streets S are formed in the X-axis direction and the Y-axis direction. After forming grooves 50 for all the streets S extending in the X-axis direction in the state of FIG. 3, the wafer W is rotated 90 degrees to similarly form grooves 50 for all the streets S extending in the Y-axis direction in the state of FIG. 3.

[0037] Next, the machining groove correction will be described. When the above-mentioned machining is repeated, a deviation may occur in the positional relationship between the street and the machined groove, and in that case, a machined groove correction is required to correct the deviation. In this embodiment, as shown in Figure 4, a monitor 40 constituting a display means is used as a device for performing the machined groove correction.

[0038] The monitor 40 displays an image display section 42 that displays an image captured by the imaging unit 7, which is an imaging means. In the example of Fig. 4, a machined groove 50 formed in a street on the surface of the wafer W is displayed on the image display section 42. As described above, the reference line K is also displayed. The reference line K is displayed, for example, as a dashed line. The image display section 42 is configured as a so-called touch screen panel, and various operations can be performed by the operator by touching the surface.

[0039] The monitor 40 displays a Y-axis direction operation unit 44 for operating the Y-axis feed means (Y-axis movement mechanism 17). In this embodiment, the Y-axis direction operation unit 44 includes a Y-axis up button 44a for moving the Y-axis movement block 18 (FIG. 2) in the Y(-) direction and moving the image displayed on the image display unit 42 upward, and a Y-axis down button 44b for moving the Y-axis movement block 18 (FIG. 2) in the Y(+) direction and moving the image displayed on the image display unit 42 downward. Each of the buttons 44a and 44b is operated by touch by the operator.

[0040] The monitor 40 displays a pair of movable lines 46a, 46b that are symmetrical with respect to the reference line K and approach and recede from the reference line K. The movable lines 46a, 46b are automatically displayed by a controller, and a distance 46w between the two movable lines 46a, 46b can be set in advance. The movable lines 46a, 46b are displayed, for example, as straight lines. The color of the movable lines 46a, 46b is, for example, the same green as the reference line K. The movable lines 46a, 46b are also called hairlines.

[0041] The monitor 40 displays a button 47a for widening the gap 46w between the pair of movable lines 46a, 46b and a button 47b for narrowing the gap 46w. By operating the buttons 47a, 47b, the operator can arbitrarily adjust the gap 46w between the pair of movable lines 46a, 46b and move the positions of the movable lines 46a, 46b in the Y-axis direction.

[0042] The monitor 40 displays a pair of machined groove recognition lines 52a, 52b that are set to match the edges 50a, 50b of the machined groove 50 recognized by image processing from within the image captured by the imaging unit 7. For example, the controller recognizes the edges 50a, 50b of the machined groove 50 by converting the image captured by the imaging unit 7 into two gradations, and sets and displays the straight machined groove recognition lines 52a, 52b at positions corresponding to the edges. The machined groove recognition lines 52a, 52b are displayed, for example, as dotted lines. The color of the machined groove recognition lines 52a, 52b is, for example, red, which is different from the color of the reference line K.

[0043] The monitor 40 displays an adjustment button 48. The color of the adjustment button 48 is, for example, red, the same color as the processing groove recognition lines 52a and 52b.

[0044] The monitor 40 displays a machined groove correction execution button 49. The machined groove correction execution button 49 is operated when storing a correction value H (FIG. 6) in the controller, as will be described in detail later.

[0045] Next, an example of a method for performing machining groove correction will be described. This machining groove correction can be performed by the operator at any timing, or by the controller stopping machining at a predetermined timing and prompting the operator to perform the correction.

[0046] The operator operates the X-axis feed means and the Y-axis feed means using an operating means (not shown), aligns the wafer 2 with the imaging unit 7, and causes the imaging unit 7 to capture an image of the street where the cutting groove 50 is formed nearby, and displays an image such as that shown in FIG. 4.

[0047] 4, the operator can visually recognize that there is a misalignment between the reference line K and the center position in the up-down direction (center position in the Y-axis direction) of the machined groove 50. Since a pair of machined groove recognition lines 52a, 52b are also displayed at the positions of the edges 50a, 50b of the machined groove 50, the operator can more easily recognize that there is a misalignment between the reference line K and the center position in the up-down direction (center position in the Y-axis direction) of the machined groove 50.

[0048] In this state, when the adjustment button 40 is touched by the operator, the controller operates the Y-axis feed means (Y-axis movement mechanism 17) to align the reference line K with the center position of the machined groove 50 in the Y-axis direction. That is, in FIG. 2, the controller 10 drives the pulse motor 16b to move the Y-axis movement block 18 in the Y-axis direction, and moves the imaging unit 7 in the Y-axis direction. Accompanying this movement in the Y-axis direction, the cutting unit 20 (cutting blade 21) also moves in the Y-axis direction by the same distance. In the state of FIG. 4, the machined groove 50 is shifted downward with respect to the reference line K, so the Y-axis movement block 18 (FIG. 2) is moved in the Y(-) direction.

[0049] At the same time, the controller aligns the movable lines 46a, 46b with the machined groove recognition lines 52a, 52b. The movable lines 46a, 46b approach and move away from the reference line K while maintaining line symmetry with respect to the reference line K. Therefore, when the movable lines 46a, 46b are aligned with the machined groove recognition lines 52a, 52b, the reference line K is aligned with the center position of the machined groove 50 in the Y-axis direction.

[0050] As described above, when the adjustment button 48 is pressed in the state shown in FIG. 4, the state shown in FIG. 5 is obtained.

[0051] Here, the amount of movement by the Y-axis feed means, that is, the amount of movement of the cutting blade 21 (Y-axis movement block 18 (FIG. 2)), is recognized and acquired as a correction value H (FIG. 6) by the controller 10. Then, when the machining groove correction execution button 49 is touched in the state shown in FIG. 5, the correction value H (FIG. 6) is stored in the controller 10, and when the next street is machined, machining is performed in the corrected state.

[0052] Specifically, in a state in which the machining groove correction is completed when a certain street S1 is machined as shown in Fig. 6(A), when machining the next unmachined adjacent street S2, the cutting blade 21 is indexed and fed in the Y(+) direction by a preset indexing feed amount Yw as shown in Fig. 6(B), and is further moved in the Y(+) direction by a correction value H as shown in Fig. 6(C). As a result, the cutting blade 21 is positioned so as to coincide with the center position in the Y-axis direction of the unmachined street S2, and a machining groove can be machined at the center position in the Y-axis direction of the street S2.

[0053] In addition, when the adjustment button 48 is touched, even if the machining groove correction execution button 49 is not touched, the correction value H is stored in the controller 10, and machining of the adjacent unmachined street may be performed in the corrected state.

[0054] According to the above embodiment, the correction value H can be obtained simply by touching the adjustment button 48, so the operator does not need to stare at the monitor 40 or make repeated fine adjustments, and the adjustment can be performed easily and in a short time. Furthermore, since the adjustment can be completed in a short time, the throughput in processing can be improved.

[0055] In addition, by storing the deviation between the center position of the machining groove 50 in the Y-axis direction and the reference line K obtained during the adjustment work as a correction value H, when the next street to be machined is machined, the previously set indexing feed amount Yw can be corrected with the correction value H, thereby improving the machining accuracy.

[0056] 6(D), after machining the machining groove for the street S2, when machining the next unmachined streets S3, S4, ..., the cutting blade 21 is indexed and fed in the Y(+) direction by the indexing feed amount Yw to perform machining. Then, for example, by performing machining groove correction after machining grooves for an arbitrary number of streets or a predetermined number of streets, a new correction value is obtained and correction is performed before machining the street Sn. [Explanation of symbols]

[0057] 2 Processing equipment 7 Imaging unit 7a Microscope 8 Holding Table 10 Controller 17 Y-axis movement mechanism 20 Cutting unit 21 Cutting blade 31b Pulse motor 32 Z-axis movement mechanism 40 Monitors 42 Image display unit 44 Y-axis direction operation section 46a Movable wire 46b Movable line 46w spacing 48 Adjustment Button 49 Cutting groove compensation execution button 50 Machining groove 50a Edge of machining groove 50b Edge of machining groove 52a Machining groove recognition line 52b Machining groove recognition line H correction value K reference line S Street W wafer Wa Surface Wb back side Yw Index feed amount

Claims

1. A processing apparatus for forming grooves for dividing a wafer having a surface on which a plurality of devices are partitioned by streets into individual devices, comprising: The wafer processing apparatus comprises at least a holding means for holding a wafer, a processing means for forming a processed groove on a street of the wafer held by the holding means, an X-axis feed means for relatively feeding the holding means and the processing means in the X-axis direction, a Y-axis feed means for relatively indexing and feeding the holding means and the processing means in the Y-axis direction perpendicular to the X-axis direction, an imaging means having a reference line set for imaging the wafer held by the holding means and detecting the processed groove, and a display means, The display means includes: an image display unit that displays an image captured by the imaging means; a Y-axis direction operation unit that operates the Y-axis feed means; A pair of movable lines that are symmetrical about the reference line and move toward and away from the reference line; a pair of processing groove recognition lines that are set so as to coincide with the edges of the processing groove recognized by image processing from within the image captured by the imaging means; The adjustment button and are displayed. When the adjustment button is touched, the Y-axis feed means is operated so as to align the reference line with the center of the machined groove, and the movable line is aligned with the machined groove recognition line.

2. 2. The machining device according to claim 1, wherein the amount of deviation between the center of the machined groove and the reference line is stored as a correction value by touching the adjustment button.

3. 3. The processing device according to claim 1, wherein the processing means is a cutting means having a rotatable cutting blade, and the processing groove is a cutting groove.

4. A processing method using the processing apparatus according to claim 2, the position of the machining means in the Y-axis direction is corrected by the correction value when machining the next unmachined street adjacent thereto, thereby forming a machined groove.

Images