Workpiece machining device and method for controlling the workpiece machining device

Abstract

To provide a work-piece processing device and a control method of the same in which measurement of processing quality of a part to be processed in a work-piece can be performed with a white-light interferometer for a short time.SOLUTION: A work-piece processing device comprises: a processing control part 78 which drives a processing head (blade 22A, 22B) and a relative movement mechanism 49 to form a part to be processed in a work-piece W; a scan control part 85 which integrates the processing head and a white-light interferometer 24 and performs step scan relatively in a direction orthogonal to a table; an interference signal acquisition part 81 which acquires interference signal from the white-light interferometer 24; an estimation part 82 which estimates a position of the white-light interferometer 24 where intensity of the interference signal becomes a peak value; and a processing quality measuring part 83 which measures at least one of a processing position of the part to be processed and a processing shape thereof based on the estimation result of the estimation part 82. The processing control part 78 executes a first processing treatment to form a first groove and a second processing treatment to form a second groove on a bottom part of the first groove.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a workpiece machining device that machines a workpiece and a method for controlling the workpiece machining device. [Background technology]

[0002] Dicing machines (workpiece processing machines) are known that cut workpieces such as wafers using a disk-shaped blade rotated at high speed by a spindle. Twin-spindle dicers, which have two spindles to which blades are attached, are also known as dicing machines. Two methods for cutting or slicing workpieces with twin-spindle dicers are known: the meeting cutting method and the step-cut method.

[0003] The meeting cutting method uses two blades to cut two streets at once, while the step cutting method cuts the wafer along the streets by cutting a groove of a specified depth along the street with the first blade and then cutting the bottom of the groove with the second blade.

[0004] The blades of such dicing machines wear down with use, which can cause chipping on the cutting surface of the workpiece. Furthermore, due to the influence of thermal deformation of the blade, the position of the groove (kerf) formed in the workpiece by the blade can shift from the center of the street. For this reason, dicing machines perform blade kerf checks at preset intervals.

[0005] For example, in the dicing devices described in Patent Documents 1 and 2, the grooves formed in the workpiece by the blade are photographed with a camera (such as an alignment microscope), and the kerf position, kerf width, and presence or absence of chipping of the groove are measured based on the image captured by this camera.

[0006] Furthermore, the laser processing machines described in Patent Documents 3 and 4 include a white light interferometer that emits white light toward a portion to be processed formed on a workpiece and detects an interference signal between the white light reflected by the portion to be processed and the white light reflected by a reference surface. This laser processing machine vertically scans the white interferometer in the Z-axis direction and acquires an interference signal output from each pixel of the white interferometer (a pixel of an imaging element that captures the interference signal) at each position in the Z-axis direction. This laser processing machine then verifies the processing state of the portion to be processed by generating a three-dimensional image of the workpiece based on the detection results obtained by detecting, for each pixel, the Z-axis position of the white interferometer where the intensity of the interference signal peaks. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-165826 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-129822 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-099026 [Patent Document 4] Japanese Patent Application Laid-Open No. 2015-38438 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the dicing devices disclosed in Patent Documents 1 and 2, images of the grooves are taken using a microscope. However, these images are two-dimensional images of the grooves viewed from the top surface of the workpiece, making it impossible to determine the depth and cross-sectional shape of the grooves based on the images. Furthermore, when the step-cut cutting process described above is performed using these dicing devices, the grooves formed by the second blade overlap with the grooves formed by the first blade. This makes it difficult to confirm the processing quality (kerf position, kerf width, etc.) of the grooves formed by the second blade based on the images taken with the microscope.

[0009] Therefore, a step kerf check is known in which an uncut portion of the workpiece is cut with a first blade, and another uncut portion of the workpiece is cut with a second blade, and the kerf of each blade is checked based on images taken with a camera of the two grooves formed by each blade (see Patent Document 2 above).In this case, the processing quality of the groove formed by the second blade can be confirmed based on the images taken with a microscope.

[0010] However, this method requires the second blade to cut the uncut portion of the workpiece. However, because the second blade is thinner than the first blade, cutting the uncut portion with the second blade places a heavy load on the second blade. Furthermore, because the processing conditions for the workpiece with the second blade differ between step cutting and kerf checking, for example, the second blade may be deflected during kerf checking, resulting in grooves being formed in a different position than when step cutting was performed. In other words, grooves may not be formed in the same position during step cutting and kerf checking, which may result in an inaccurate measurement of the groove processing quality during step cutting.

[0011] On the other hand, in the laser processing machines described in Patent Documents 3 and 4, a white light interferometer is scanned vertically in the Z-axis direction, and the depth and cross-sectional shape of the groove are measured based on the interference signal output from the white light interferometer at each position in the Z-axis direction, so the problems described in the dicing devices of Patent Documents 1 and 2 do not occur.

[0012] However, when vertically scanning a white light interferometer to detect the Z-axis position of the white light interferometer where the intensity of the interference signal peaks for each pixel of the white light interferometer (hereinafter referred to as the peak position) as described in Patent Documents 3 and 4, it is necessary to acquire the interference signal from the white light interferometer at a high sampling rate (fine pitch) that can reliably detect the peak position for each pixel. Furthermore, when using a white light interferometer to measure the cross-sectional shape of a groove, the vertical scanning movement range (movement amount) must be increased compared to when measuring the surface roughness of various general measurement objects. Therefore, detecting the interference signal at the aforementioned high sampling rate poses the problem of significantly longer time required to measure the cross-sectional shape of the groove.

[0013] The present invention has been made in consideration of the above circumstances, and aims to provide a workpiece processing device and a control method for a workpiece processing device that are capable of measuring the processing quality of the processed portion of a workpiece using a white light interferometer in a short period of time. [Means for solving the problem]

[0014] A workpiece processing device for achieving the object of the present invention includes a table for holding a flat workpiece, a processing head for processing the workpiece held on the table, a relative movement mechanism for moving the processing head relative to the table, a white interferometer integrated with the processing head, which emits white light toward a processed portion formed on the workpiece and detects, for each pixel, an interference signal between the white light reflected by the processed portion and the white light reflected by a reference surface, a scan control unit that drives the relative movement mechanism to relatively step-scan the processing head and the white interferometer together in a direction perpendicular to the table, an interference signal acquisition unit that acquires an interference signal for each pixel from the white interferometer for each step of the step scan, and an estimation unit that estimates, for each pixel, the position of the white interferometer at which the intensity of the interference signal peaks, based on the interference signal for each pixel acquired for each step by the interference signal acquisition unit.

[0015] According to this workpiece processing device, the position of the white interferometer where the intensity of the interference signal peaks can be estimated for each pixel based on the interference signal acquired from the white interferometer for each pixel at each step of the step scan, eliminating the need to vertically scan the white interferometer at a high sampling rate (fine pitch).

[0016] In the workpiece machining device according to another aspect of the present invention, the scan control unit has a function of adjusting the step width of the step scan, thereby making it possible to adjust the step width (number of steps) depending on the type of workpiece, etc.

[0017] In a workpiece machining device according to another aspect of the present invention, the scanning range of the step scan is divided into multiple scanning ranges according to the location of the workpiece, and the scan control unit adjusts the step width of the step scan for each scanning range based on the step width determined for each scanning range. This makes it possible to perform the step scan of the white interferometer at a high sampling rate in areas important for measuring the machining quality of the workpiece, and to perform the step scan of the white interferometer at a low sampling rate in areas that do not have much of an impact on the machining quality measurement. As a result, the machining quality of the workpiece can be measured accurately in a short time.

[0018] In accordance with another aspect of the present invention, a workpiece machining apparatus includes a machining quality measurement unit that measures the machining quality of the machined portion based on the estimation result of the estimation unit. By performing step scanning of the white light interferometer, it is possible to measure the machining quality of the machined portion of the workpiece using the white light interferometer in a short time.

[0019] In another aspect of the present invention, a workpiece machining apparatus includes a machining control unit that drives the machining head and the relative movement mechanism to form a machined portion on the workpiece using the machining head, and a measurement control unit that operates the white light interferometer and the scan control unit at a position where the machined portion can be irradiated with white light, and a machining quality measurement unit that measures at least one of the machining position and the machining shape of the machined portion as the machining quality. This makes it possible to measure the machining quality of the machined portion formed by the machining head in a short period of time.

[0020] In a workpiece machining apparatus according to another aspect of the present invention, the measurement control unit drives the relative movement mechanism to relatively move the white interferometer to a position where the white light can be irradiated onto the workpiece, based on a known position of the workpiece formed by the machining head. This makes it possible to quickly adjust the position of the white interferometer with respect to the workpiece, without searching for the workpiece.

[0021] In another aspect of the present invention, the workpiece machining device includes a correction value determination unit that determines a correction value for correcting at least one of the machining position and the machining shape of the workpiece based on the measurement results of the machining quality measurement unit, and a machining control unit that drives the machining head and the relative movement mechanism based on the correction value determined by the correction value determination unit to form the workpiece on the workpiece. This makes it possible to further improve the machining accuracy of the workpiece.

[0022] In a workpiece processing device according to another aspect of the present invention, the processing head cuts the workpiece with a rotating disk-shaped blade.

[0023] In a workpiece processing device according to another aspect of the present invention, a processing head cuts a workpiece with a rotating disk-shaped blade, a processing quality measuring unit measures the cross-sectional shape of the processed portion as processing quality, and a blade shape measuring unit measures the tip shape of the blade based on the cross-sectional shape measurement results by the processing quality measuring unit. This makes it possible to measure the tip shape of the blade in a short time.

[0024] A control method for a workpiece processing device for achieving the object of the present invention includes a scanning control step of relatively step-scanning a white interferometer, which emits white light toward a processed portion formed on a flat workpiece held on a table and detects, for each pixel, an interference signal between the white light reflected by the processed portion and the white light reflected by a reference surface, together with a processing head that processes the workpiece, along a direction perpendicular to the table; an interference signal acquisition step of acquiring an interference signal for each pixel from the white interferometer for each step of the step scan; and an estimation step of estimating, for each pixel, the position of the white interferometer where the intensity of the interference signal peaks, based on the interference signal for each pixel acquired for each step in the interference signal acquisition step.

[0025] A method for controlling a workpiece machining device according to another aspect of the present invention includes a machining quality measuring step of measuring the machining quality of the workpiece based on the estimation result in the estimation step. [Effects of the Invention]

[0026] The present invention makes it possible to measure the machining quality of the machined portion of a workpiece using a white light interferometer in a short time. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a perspective view of a dicing device according to a first embodiment. [Figure 2] FIG. [Figure 3] FIG. 3 is an enlarged front view of the white light interferometer shown in FIG. 2. [Figure 4] FIG. 1 is a cross-sectional view of a white light interferometer. [Figure 5] FIG. 2 is a functional block diagram of a general control unit of the dicing device of the first embodiment. [Figure 6] FIG. 10 is an explanatory diagram for explaining a meeting cutting method. [Figure 7] FIG. 10 is an explanatory diagram for explaining a step cut method. [Figure 8] FIG. 1 is a cross-sectional view of a portion of a workpiece cut by a step cutting method. [Figure 9]FIG. 10 is an explanatory diagram for explaining step scanning in the Z-axis direction of the white light interferometer. [Figure 10] 10 is an explanatory diagram for explaining the estimation process of the peak position of the white light interferometer by the estimation unit. FIG. [Figure 11] 10 is an explanatory diagram for explaining shape measurement of the three-dimensional shape of a groove by a processing quality measuring unit. FIG. [Figure 12] 10 is an explanatory diagram for explaining shape measurement of a cross-sectional shape of a groove along the Y-axis direction by a processing quality measuring unit. FIG. [Figure 13] 10 is an explanatory diagram for explaining a kerf check of a groove formed by a step cut method, that is, an example of measuring the machining position of the groove in the workpiece. FIG. [Figure 14] 4 is a flowchart showing the flow of a cutting process of a workpiece by the dicing device of the first embodiment, and in particular the flow of a process of measuring the processing quality (processing position) of a groove. [Figure 15] 10 is an explanatory diagram for explaining cutting of a workpiece by a dicing device of a second embodiment and back grinding of the workpiece by a grinding (polishing) device (not shown). FIG. [Figure 16] 10 is an explanatory diagram for illustrating shape measurement of a cross-sectional shape of a half-cut groove along the Y-axis direction by a processing quality measuring unit of the second embodiment. FIG. [Figure 17] FIG. 10 is a functional block diagram of a general control unit of a dicing device according to a third embodiment. [Figure 18] 10 is an explanatory diagram for explaining shape measurement of the cross-sectional shape of a half-cut groove by a processing quality measuring unit of the third embodiment. FIG. [Figure 19] 10 is a flowchart showing the flow of a process for measuring the shape of the tip of the blade by the dicing device of the third embodiment. [Figure 20] FIG. 10 is an explanatory diagram for explaining step scanning of a white light interferometer by the dicing apparatus of the fourth embodiment. [Figure 21] 21 is an enlarged view of a groove in FIG. 20 and is a view for explaining the position of a reference light-focusing point of measurement light for each step of step scanning in the fourth embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0028] [First embodiment] 1 is a perspective view of a dicing apparatus 10 of the first embodiment. Note that the X, Y, and Z axes in the figure are mutually perpendicular, with the X and Y axes being parallel to the horizontal direction and the Z axis being perpendicular to the horizontal direction.

[0029] The dicing device 10 corresponds to the workpiece processing device of the present invention, and cuts and processes a flat workpiece W such as a semiconductor wafer. The dicing device 10 includes a load port 12, a transfer mechanism 14, a processing unit 16, and a cleaning unit 18.

[0030] A cassette containing a large number of workpieces W mounted on a frame F is placed on the load port 12. A transport mechanism 14 transports the workpieces W. A processing unit 16 dices the workpieces W. A cleaning unit 18 spin-cleans the diced workpieces W. Inside the housing 10A of the dicing device 10 is provided a general control unit 60 (see FIG. 5) that controls the operation of each part of the dicing device 10. The general control unit 60 may also be provided outside the housing 10A.

[0031] An unmachined (uncut) workpiece W stored in a cassette placed on the load port 12 is transported by the transport mechanism 14 to the processing unit 16, where it is subjected to cutting or grooving or other cutting processes to separate it into individual chips. The workpiece W that has been processed by the processing unit 16 is then transported by the transport mechanism 14 to the cleaning unit 18, where it is cleaned, and then transported by the transport mechanism 14 to the load port 12 and stored in a cassette.

[0032] Fig. 2 is an external perspective view of processing unit 16. As shown in Fig. 2 and the above-mentioned Fig. 1, processing unit 16 is the above-mentioned twin-spindle dicer, and includes a pair of blades 21A, 21B, a blade cover (not shown), a pair of spindles 22A, 22B, a microscope 23, a white light interferometer 24, and a table 31.

[0033] Blades 21A and 21B are formed in a disk shape. The tip shapes of blades 21A and 21B, i.e., the cross-sectional shapes of the outer peripheries (cutting edges) of blades 21A and 21B along the radial direction of blades 21A and 21B, are rectangular (other shapes such as V-shapes are also acceptable). Blades 21A and 21B are arranged opposite each other in the Y-axis direction and are held by spindles 22A and 22B so as to be rotatable about blade rotation axes parallel to the Y-axis direction.

[0034] The spindles 22A and 22B each have a built-in high-frequency motor that rotates the blades 21A and 21B at high speed around the blade rotation axis. This causes the blades 21A and 21B to cut the workpiece W from its front surface. Therefore, the blade 21A and spindle 22A, and the blade 21B and spindle 22B each correspond to the machining heads of the present invention.

[0035] By cutting the workpiece W with the blade 21A, a groove 25A (see FIGS. 6 and 7) corresponding to the processed portion of the present invention is formed in the workpiece W. Also, by cutting the workpiece W with the blade 21B, a groove 25B (see FIGS. 6 and 7) corresponding to the processed portion of the present invention is formed in the workpiece W.

[0036] The microscope 23 is mounted on the Z carriage 44 integrally with the spindle 22A, and is held by the Y carriage 43 and the Z carriage 44 so as to be movable in the Y and Z axes together with the spindle 22A. Although not shown, the microscope 23 is an imaging device having an imaging optical system and an image sensor [for example, a COMS (Complementary Metal Oxide Semiconductor) camera]. Note that the microscope 23 may be composed of a high-magnification microscope and a low-magnification microscope with different imaging magnifications. The microscope 23 photographs the front surface of the workpiece W when the workpiece W is being cut. The image of the workpiece W photographed by the microscope 23 is used for aligning the workpiece W with the blades 21A and 21B.

[0037] Fig. 3 is an enlarged front view of white interferometer 24 shown in Fig. 2. As shown in Fig. 3 and the above-described Fig. 2, white interferometer 24 is provided integrally with spindle 22B on Z carriage 44, and is held by Y carriage 43 and Z carriage 44 so as to be movable in the Y and Z axes directions. White interferometer 24 is used to measure the processing quality of grooves 25A and 25B (see Figs. 6 and 7) formed in workpiece W by blades 21A and 21B. During measurement of this processing quality, white interferometer 24 is vertically scanned, more specifically, step-scanned, in the Z axis direction perpendicular to table 31 (workpiece W) via Z carriage 44.

[0038] The table 31 has a workpiece holding surface 31a formed in a porous state, and this workpiece holding surface 31a adsorbs and holds the workpiece W from its back side. The table 31 is held by an X carriage 36 (described later) so as to be movable in the X-axis direction, and is held by a rotation unit 37 (described later) so as to be rotatable about a rotation axis CA.

[0039] Processing section 16 is provided with X base 32, X guide 34, X drive section 35, X carriage 36, and rotation unit 37. X base 32 has a flat plate shape extending in the X-axis direction, and X guide 34 is provided on its upper surface in the Z-axis direction. X guide 34 has a shape that extends in the X-axis direction, and guides X carriage 36 along the X-axis direction. X drive section 35 uses an actuator such as a linear motor, and moves (drives) X carriage 36 in the X-axis direction along X guide 34.

[0040] Rotation unit 37 is provided on the upper surface of X-carriage 36. Table 31 is provided on the upper surface of rotation unit 37. Rotation unit 37 is rotationally driven by rotation drive section 38 (see FIG. 5) which is composed of a motor, gears, etc. As a result, rotation unit 37 rotates table 31 in the θ direction around its rotation axis CA.

[0041] The workpiece W transferred from the load port 12 by the transfer mechanism 14 is held by suction on the table 31, and moves and rotates integrally with the table 31.

[0042] Processing unit 16 is also provided with a Y base 41, a Y guide 42, a pair of Y carriages 43, and a pair of Z carriages 44. Y base 41 has a gate-like shape that straddles X base 32 in the Y-axis direction. Y guide 42 is provided on a side surface of Y base 41 in the X-axis direction. Y guide 42 has a shape that extends in the Y-axis direction, and guides each of the pair of Y carriages 43 along the Y-axis direction. The pair of Y carriages 43 are driven independently along Y guide 42 by Y drive unit 46 (see FIG. 5), which is an actuator constituted by, for example, a stepping motor, a ball screw, etc.

[0043] Z carriage 44 is provided on each of the pair of Y carriages 43 so as to be movable in the Z-axis direction via Z drive unit 48 (see FIG. 5) configured with an actuator such as a stepping motor. Spindle 22A and microscope 23 are provided on one side of Z carriage 44, and spindle 22B and white light interferometer 24 are provided on the other side of Z carriage 44.

[0044] By driving the X carriage 36, the rotation unit 37, each Y carriage 43, and each Z carriage 44, the blades 21A, 21B, the microscope 23, and the white interferometer 24 can be moved relative to the table 31 and the workpiece W in the X, Y, and Z axis directions and the θ direction.

[0045] Fig. 4 is a cross-sectional view of the white interferometer 24. As shown in Fig. 4, the white interferometer 24 is a so-called Mirau-type white interferometer, and includes a housing 50, a white light source 51, a first beam splitter 52, an objective lens 53, a glass plate 54, a second beam splitter 55, and an imaging unit 56.

[0046] The housing 50 accommodates a first beam splitter 52, an objective lens 53, a glass plate 54, and a second beam splitter 55. Inside the housing 50, the second beam splitter 55, the glass plate 54, the objective lens 53, and the first beam splitter 52 are arranged from the bottom to the top in the Z-axis direction. A white light source 51 is attached to a side surface of the housing 50 and to the side of the first beam splitter 52. An imaging unit 56 is attached to the top surface of the housing 50 and above the first beam splitter 52.

[0047] While the white interferometer 24 is scanning one step (or multiple steps), the white light source 51 emits white light L1 (light containing a mixture of light in each wavelength range of visible light) toward the first beam splitter 52. The first beam splitter 52 reflects a portion of the white light L1 incident from the white light source 51 toward the objective lens 53. The first beam splitter 52 also transmits a portion of the interference signal L4 incident from the objective lens 53 and emits this portion toward the imaging unit 56.

[0048] The objective lens 53 focuses the white light L1 incident from the first beam splitter 52 onto a focal point P on the workpiece W. The diameter of the focal point P (focused spot) is not particularly limited.

[0049] The glass plate 54 has a mirror 54a in its center that functions as a reference surface. The glass plate 54 (excluding the mirror 54a) transmits the white light L1 incident from the objective lens 53 as is and emits it toward the second beam splitter 55.

[0050] The second beam splitter 55 splits the white light L1 collected by the objective lens 53 into measurement light L2 and reference light L3, transmits the measurement light L2 to irradiate the workpiece W, and reflects the reference light L3 toward the mirror 54a. The measurement light L2 irradiated to the workpiece W is reflected by the workpiece W and enters the second beam splitter 55. The reference light L3 reflected by the mirror 54a enters the second beam splitter 55, and a portion of it is reflected by the second beam splitter 55. This generates an interference signal L4 (interference light) between the measurement light L2 and the reference light L3. This interference signal L4 passes through the glass plate 54, the objective lens 53, and the first beam splitter 52 and enters the imaging unit 56.

[0051] The optical path length of the reference light L3 is constant, but the optical path length of the measurement light L2 changes in response to the vertical scanning of the white light interferometer 24. As is well known, when the difference in optical path length between the measurement light L2 and the reference light L3 is zero (including almost zero), the interference between the measurement light L2 and the reference light L3 is constructive across the entire wavelength range of visible light, and the signal intensity of the interference signal L4 is maximized (see, for example, JP 2017-106860 A).

[0052] The imaging unit 56 includes a two-dimensional imaging element of a CCD (Charge Coupled Device) type or a CMOS (Complementary Metal Oxide Semiconductor) type in which a plurality of pixels (light receiving elements) are two-dimensionally arranged in the X and Y axes directions. The imaging unit 56 captures the interference signal L4 incident from the first beam splitter 52 for each pixel while the white light interferometer 24 is being vertically scanned (or multiple times), thereby detecting (acquiring) the interference signal L4 for each pixel and outputting the interference signal L4 for each pixel to the general control unit 60 (see FIG. 5).

[0053] [Functions of the central control unit] FIG. 5 is a functional block diagram of the integrated control unit 60 of the dicing apparatus 10 of the first embodiment. As shown in FIG. 5, the integrated control unit 60 includes an arithmetic circuit configured with various processors, memory, and the like. The various processors include a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), and a programmable logic device (e.g., a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA)). The various functions of the integrated control unit 60 may be realized by a single processor or by multiple processors of the same or different types.

[0054] In addition to the spindles 22A, 22B, microscope 23, white light interferometer 24, X drive unit 35, rotation drive unit 38, Y drive unit 46, and Z drive unit 48, an operation unit 62, a memory unit 64, a display unit 66, etc. are connected to the overall control unit 60.

[0055] The operation unit 62 uses a keyboard, mouse, operation panel, operation buttons, etc., and accepts input of various operations by an operator. The memory unit 64 stores a control program (not shown) for the dicing apparatus 10, and also stores measurement results by a processing quality measurement unit 83 (described below). The display unit 66 uses various known monitors, such as a liquid crystal display. This display unit 66 displays the measurement results by the processing quality measurement unit 83, various setting screens for the dicing apparatus 10, etc.

[0056] The overall control unit 60 executes a control program (not shown) stored in the storage unit 64, thereby functioning as a blade drive control unit 70, a movement control unit 72, an imaging control unit 74, a detection control unit 76, a processing control unit 78, a measurement control unit 80, an interference signal acquisition unit 81, an estimation unit 82, a processing quality measurement unit 83, and a correction value determination unit 84. Note that what is described as a "unit" of the overall control unit 60 may also be a "circuit," a "device," or a "device." In other words, what is described as a "unit" may be composed of firmware, software, hardware, or a combination of these.

[0057] The blade drive control unit 70 controls the rotational drive of the blades 21A and 21B by the spindles 22A and 22B.

[0058] The movement control unit 72 drives a relative movement mechanism 49 including an X drive unit 35 (X carriage 36), a rotation drive unit 38 (rotation unit 37), a Y drive unit 46 (Y carriage 43), and a Z drive unit 48 (Z carriage 44), thereby moving the blades 21A, 21B, the microscope 23, and the white light interferometer 24 relative to the table 31 and the workpiece W.

[0059] For example, before aligning the workpiece W with the blades 21A and 21B, the movement control unit 72 drives the relative movement mechanism 49 to adjust the position of the microscope 23 to a position where it can capture an image of a predetermined alignment reference on the workpiece W. The alignment reference here is a reference that the dicing device 10 uses to recognize the position of the street C (see FIG. 6, etc., also referred to as the planned dividing line) on the workpiece W, and for example, a recognition mark or the like is used.

[0060] Furthermore, when aligning the workpiece W with the blades 21A, 21B, the movement control unit 72 drives the relative movement mechanism 49 to align the blades 21A, 21B with the machining start position of the workpiece W.

[0061] Furthermore, when cutting the workpiece W with the blades 21A and 21B, the movement control unit 72 drives the relative movement mechanism 49 to perform cutting feed of the workpiece W in the X direction, index feed of the blades 21A and 21B in the Y axis direction, and cutting feed of the blades 21A and 21B in the Z axis direction.

[0062] Furthermore, when measuring the processing quality of grooves 25A, 25B (see FIGS. 6 and 7) formed in the workpiece W by the blades 21A, 21B, the movement control unit 72, under the control of a measurement control unit 80 described later, drives the relative movement mechanism 49 to adjust the position of the white interferometer 24, and also functions as a scan control unit 85. Under the control of the measurement control unit 80, this scan control unit 85 executes step scanning of the white interferometer 24 in the Z-axis direction.

[0063] The photographing control unit 74 controls photographing of the workpiece W by the microscope 23. After adjusting the position of the microscope 23 as described above, the photographing control unit 74 causes the microscope 23 to photograph the workpiece W. As a result, the photographed image of the workpiece W is output from the microscope 23 to the detection control unit 76.

[0064] The detection control unit 76 performs alignment detection to detect the position of the street C (see FIGS. 6 and 7) of the workpiece W by detecting alignment standards in the captured image using a known image recognition method based on the captured image of the workpiece W input from the microscope 23. Then, the detection control unit 76 outputs the alignment detection result to the processing control unit 78.

[0065] Based on the alignment detection result by the detection control unit 76, the processing control unit 78 drives the spindles 22A, 22B and the relative movement mechanism 49 via the blade drive control unit 70 and the movement control unit 72 to perform cutting processing with the blades 21A, 21B for each street C (see FIG. 6) of the workpiece W. Here, since the dicing apparatus 10 of this embodiment is a so-called twin-spindle dicer, the processing control unit 78 selectively executes, for example, a meeting cutting method or a step cut method as the cutting method for the workpiece W. The selection of the cutting method is performed by the operation unit 62.

[0066] Fig. 6 is an explanatory diagram for explaining the meeting cutting method. As shown in Fig. 6, in the meeting cutting method, blades 21A and 21B of the same shape (same thickness) are attached to spindles 22A and 22B. Based on the alignment detection result by the detection control unit 76, the machining control unit 78 drives the spindles 22A and 22B and the relative movement mechanism 49 via the blade drive control unit 70 and the movement control unit 72 to repeatedly perform simultaneous machining for each of two streets C.

[0067] Simultaneous machining is a process in which two streets C are cut at once using two blades 21A and 21B of the same shape, and grooves 25A and 25B are formed by blade 21A and blade 21B, respectively, simultaneously. Note that grooves 25A and 25B formed by the meeting cutting method are so-called full-cut grooves of approximately the same shape. With the meeting cutting method, the cutting range of the workpiece W can be divided into two, and each range can be assigned to a different blade 21A or 21B, thereby shortening the machining time for the workpiece W.

[0068] FIG. 7 is an explanatory diagram illustrating the step cut method. FIG. 8 is a cross-sectional view of a portion of a workpiece W cut by the step cut method. As shown in FIGS. 7 and 8, the step cut method is selected when the workpiece W is a laminate in which a low-dielectric-constant insulating film (low-k film) and a functional film forming a circuit are laminated on the surface of a substrate such as silicon. In this step cut method, blades 21A and 21B of different thicknesses (or blades 21A and 21B of the same shape) are attached to spindles 22A and 22B. Then, in the step cut method, grooves 25A and 25B are formed for each street C by the blades 21A and 21B.

[0069] Specifically, based on the alignment detection results by the detection control unit 76, the processing control unit 78 drives the spindles 22A, 22B and the relative movement mechanism 49 via the blade drive control unit 70 and the movement control unit 72, respectively, to repeatedly perform the first processing process and the second processing process for each street C.

[0070] The first processing step is a step of cutting the street C with a wide blade 21A, for example, about 50 μm wide, to form a groove 25A (corresponding to the first groove of the present invention) of a predetermined depth along the street C. In the step-cut method, the groove 25A is a so-called half-cut groove. This removes the low-k film and the like on the street C.

[0071] The second processing step is a step in which the bottom of groove 25A is cut with blade 21B, which has a width of, for example, about 30 μm, to form groove 25B. In the step-cut method, groove 25B is a so-called full-cut groove that is narrower than groove 25A. This divides the workpiece W along the street C.

[0072] The measurement control unit 80 operates the movement control unit 72 (scan control unit 85), the white light interferometer 24, and the interference signal acquisition unit 81 when measuring the processing quality of the grooves 25A, 25B formed in the workpiece W by the blades 21A, 21B.

[0073] When the step-cut method described above is selected, the measurement control unit 80 first drives the relative movement mechanism 49 via the movement control unit 72 to perform position adjustment, which moves the white interferometer 24 relatively to a position where the measurement light L2 can be irradiated onto the grooves 25A and 25B to be measured along the same street C of the workpiece W. Here, the positions of the grooves 25A and 25B formed in the workpiece W by the blades 21A and 21B are known. Therefore, the measurement control unit 80 drives the relative movement mechanism 49 to adjust the position of the white interferometer 24 relative to the grooves 25A and 25B based on the known positions of the grooves 25A and 25B. This eliminates the need to search for the grooves 25A and 25B. Note that if the grooves 25A and 25B are present within the irradiation range (within the spot) of the measurement light L2 without performing the position adjustment of the white interferometer 24, for reasons such as a sufficiently large spot diameter of the measurement light L2 emitted from the white interferometer 24, this position adjustment may be omitted.

[0074] Next, the measurement control unit 80 activates the scan control unit 85 and the white light interferometer 24 to start step scanning of the white light interferometer 24 in the Z-axis direction.

[0075] 9 is an explanatory diagram for explaining step scanning in the Z-axis direction of the white interferometer 24. Note that in FIG. 9, to clarify each part, the white interferometer 24, grooves 25A and 25B, step width d, etc. are partially exaggerated and the relative sizes of these components are ignored (this is also true for other figures). Also, the symbol FP in FIG. 9 denotes the reference focusing point, which is the focusing point P of the measurement light L2 where the optical path length difference between the measurement light L2 and the reference light L3 is zero (including almost zero), i.e., the reference focusing point of the measurement light L2 where the signal intensity of the interference signal L4 is maximum.

[0076] As shown by symbols IXA to IXD in Figure 9 and the above-mentioned Figure 5, the scan control unit 85, under the control of the measurement control unit 80, drives the relative movement mechanism 49 (Z drive unit 48) to cause the white light interferometer 24 to perform step scanning along the Z-axis direction.

[0077] Specifically, the scan control unit 85 drives the relative movement mechanism 49 based on a predetermined scanning range and step width d (also referred to as the number of samples or sampling rate) to repeatedly perform step movement, which moves the white interferometer 24 in the Z-axis direction by the step width d within the scanning range. This allows the reference focal point FP of the measurement light L2 of the white interferometer 24 to be step-scanned (step-moved) along the Z-axis. Note that there is a correlation between the step width d of step scanning and the number of steps, so determining the step width d also includes determining the number of steps.

[0078] Here, since the design values ​​of the machining shape (machining depth) of grooves 25A and 25B and the thickness of workpiece W are known, the Z-axis direction positions (design values) of the front surface of workpiece W and the bottom surfaces of grooves 25A and 25B are also known. Therefore, when performing step scanning of white light interferometer 24, the scanning range and step width d (number of steps) of step scanning that allows reference focal point FP to scan the range from the front surface of workpiece W to the bottom surfaces of grooves 25A and 25B can be determined in advance. The determined results of the scanning range and step width d are then set in the scan control unit 85 via, for example, the operation unit 62 or an external input interface (not shown). This allows the scan control unit 85 to adjust the scanning range and step width d of step scanning.

[0079] At the same time, the measurement control unit 80 operates the white interferometer 24, i.e., operates the white light source 51 and the imaging unit 56, for each step (also referred to as a sampling point or a measurement point) of the step scanning of the white interferometer 24. As a result, the measurement light L2 is irradiated from the white interferometer 24 onto the grooves 25A, 25B for each step of the step scanning, and the imaging unit 56 captures an interference signal L4 for each pixel and outputs the interference signal L4 to the interference signal acquisition unit 81. Note that the white interferometer 24 may always irradiate the measurement light L2 and capture the interference signal L4, and only output the interference signal L4 to the interference signal acquisition unit 81 intermittently for each step of the step scanning.

[0080] When the aforementioned meeting cutting method is selected, the measurement control unit 80 controls the movement control unit 72, the scanning control unit 85, and the white interferometer 24 to individually adjust the position of the white interferometer 24, perform step scanning of the white interferometer 24, and operate the white interferometer 24 for each step for each groove 25A, 25B.

[0081] 5, the interference signal acquisition unit 81 is connected to the imaging unit 56 of the white interferometer 24 via a communication interface (not shown). The interference signal acquisition unit 81 acquires an interference signal L4 (hereinafter abbreviated as interference signal group L5) for each pixel from the imaging unit 56 for each step of the step scan of the white interferometer 24. Hereinafter, the interference signal L4 for each pixel of the imaging unit 56 acquired for each step will be simply abbreviated as "interference signal group L5."

[0082] When the above-described meet cutting method is selected, the interference signal acquisition unit 81 acquires the interference signal group L5 for each of the grooves 25A and 25B from the white interferometer 24. When the above-described step cutting method is selected, the interference signal acquisition unit 81 acquires the interference signal group L5 corresponding to the grooves 25A and 25B along the same street C from the white interferometer 24. Then, the interference signal acquisition unit 81 outputs the interference signal group L5 to the estimation unit 82.

[0083] Fig. 10 is an explanatory diagram for explaining the estimation process of the peak position Z0 of the white interferometer 24 by the estimation unit 82. Note that the horizontal axis of Fig. 10 indicates the Z-axis position of the white interferometer 24 during step scanning, and the vertical axis indicates the signal intensity of the interference signal L4.

[0084] 10 and the above-described FIG. 5, the estimation unit 82 estimates a peak position Z0, which is the Z-axis position of the white interferometer 24 where the intensity of the interference signal L4 reaches a peak (maximum) for each pixel of the imaging unit 56, based on the interference signal group L5 input from the interference signal acquisition unit 81. In other words, the peak position Z0 is the Z-axis position of the white interferometer 24 where the optical path length difference between the measurement light L2 and the reference light L3 becomes zero. Also, FIG. 10 illustrates an example of estimating the peak position Z0 of the white interferometer 24 corresponding to any one pixel of the imaging unit 56.

[0085] First, the estimation unit 82 detects the signal intensity SG of the interference signal L4 for each step (here, the first step to the eighth step) of the step scan corresponding to any one pixel of the imaging unit 56 based on the interference signal group L5.

[0086] Next, the estimation unit 82 calculates a peak intensity SGM of the signal intensity SG based on the signal intensity SG for each step of the step scan. As described above, the signal intensity SG of the interference signal L4 is maximum (peak intensity SGM) when the optical path length difference between the measurement light L2 and the reference light L3 becomes zero, and decreases as the absolute value of this optical path length difference increases from zero. Therefore, the estimation unit 82 can calculate the peak intensity SGM from the signal intensity SG for each step by using an estimation algorithm such as a known fitting process.

[0087] Then, based on the calculation result of the peak intensity SGM, the estimation unit 82 estimates the Z-axis position of the white interferometer 24 corresponding to this peak intensity SGM as the peak position Z0 of the white interferometer 24 corresponding to any one pixel described above. By estimating the peak position Z0 of the white interferometer 24 based on the signal intensity SG for each step of the step scan in this way, the number of samples (sampling rate) of the step scan of the white interferometer 24 can be reduced.

[0088] In the same manner, the estimation unit 82 estimates the peak position Z0 for each pixel of the imaging unit 56, and outputs the estimation results of the peak position Z0 for each pixel to the processing quality measurement unit 83. When the above-mentioned meet cutting method is selected, the estimation unit 82 outputs the estimation results of the peak position Z0 for each pixel obtained for each groove 25A, 25B to the processing quality measurement unit 83. When the above-mentioned step cutting method is selected, the estimation unit 82 outputs the estimation results of the peak position Z0 for each pixel corresponding to the grooves 25A, 25B along the same street C to the processing quality measurement unit 83.

[0089] 5, the machining quality measuring unit 83 performs a so-called kerf check to measure the machining quality (also referred to as the machining state) of the grooves 25A, 25B formed in the workpiece W, based on the estimation result of the peak position Z0 for each pixel of the imaging unit 56 input from the estimation unit 82. Note that the machining quality of the grooves 25A, 25B in the first embodiment refers to the machining positions of the grooves 25A, 25B, i.e., the positions in the Y-axis direction.

[0090] Fig. 11 is an explanatory diagram for explaining shape measurement of the three-dimensional shape of grooves 25A, 25B by the processing quality measuring unit 83. Fig. 12 is an explanatory diagram for explaining shape measurement of the cross-sectional shape of grooves 25A, 25B along the Y-axis direction by the processing quality measuring unit 83. Note that Figs. 11 and 12 will be explained using as an example shape measurement (kerf check) of grooves 25A, 25B formed by the step cut method described above with reference to Fig. 7 etc.

[0091] As shown in FIGS. 11, 12, and the previously described FIG. 5, the machining quality measuring unit 83 calculates the height of each pixel of the imaging unit 56, i.e., the height in the Z-axis direction of the corresponding position on the workpiece W (the inner surfaces of the grooves 25A and 25B, and the front surface of the workpiece W) corresponding to each pixel, based on the estimated peak position Z0 for each pixel of the white light interferometer 24 (imaging unit 56). Note that since the method for calculating this height position is a well-known technique, a detailed description thereof will be omitted here. As a result, the machining quality measuring unit 83 can generate three-dimensional shape information 86 indicating the three-dimensional shapes of the grooves 25A and 25B as shown in FIG. 11. The machining quality measuring unit 83 can also generate cross-sectional shape information 88 indicating the cross-sectional shapes of the grooves 25A and 25B along the Y-axis direction as shown in FIG. 12.

[0092] At this time, the positional relationship between the workpiece W and the white interferometer 24 is known based on the alignment detection result by the detection control unit 76. Therefore, the processing quality measuring unit 83 can simultaneously calculate the position coordinates in the X and Y axes of the corresponding positions of the workpiece W corresponding to each pixel of the imaging unit 56 (hereinafter abbreviated as workpiece-corresponding position coordinates) based on the position coordinates in the X and Y axes of the white interferometer 24 during step scanning. As a result, the processing positions of the grooves 25A, 25B in the workpiece W can be individually determined based on at least one of the three-dimensional shape information 86 and the cross-sectional shape information 88 and the workpiece-corresponding position coordinates.

[0093] 13 is an explanatory diagram for explaining a kerf check of grooves 25A, 25B formed by the step cut method, i.e., an example of measuring the machining positions of grooves 25A, 25B in workpiece W. As shown in FIG. 13 and the already-described FIG. 5, the machining quality measurement unit 83 calculates a groove center position CL1 in the Y-axis direction of groove 25A in workpiece W and calculates a groove center position CL2 in the Y-axis direction of groove 25B based on at least one of three-dimensional shape information 86 and cross-sectional shape information 88 and the workpiece-corresponding position coordinates. Groove center position CL1 corresponds to the machining position of groove 25A, and groove center position CL2 corresponds to the machining position of groove 25B.

[0094] Then, the machining quality measuring unit 83 outputs the measurement results of the machining position of groove 25A (groove center position CL1) and the machining position of groove 25B (groove center position CL2) to the correction value determining unit 84, the memory unit 64, and the display unit 66. As a result, the measurement results of the machining positions of grooves 25A and 25B are stored in the memory unit 64 and displayed on the display unit 66.

[0095] The correction value determination unit 84 determines a correction value Δy1 for correcting the machining position of the groove 25A by the blade 21A in the Y-axis direction, and a correction value Δy2 for correcting the machining position of the groove 25B by the blade 21B in the Y-axis direction.

[0096] Specifically, the correction value determination unit 84 is preset with target values ​​for the machining positions of the grooves 25A and 25B corresponding to the type of workpiece W, for example, the Y-axis position of the street C within the workpiece W. As a result, the correction value determination unit 84 determines a correction value Δy1 based on the measurement result (groove center position CL1) of the machining position of the groove 25A by the machining quality measurement unit 83 and the target value for the machining position of the groove 25A. In addition, the correction value determination unit 84 determines a correction value Δy2 based on the measurement result (groove center position CL2) of the machining position of the groove 25B by the machining quality measurement unit 83 and the target value for the machining position of the groove 25B.

[0097] Then, the correction value determination unit 84 outputs the determined correction values ​​Δy1, Δy2 to the above-mentioned machining control unit 78. As a result, the machining control unit 78 corrects the machining positions (Y-axis direction positions) of the grooves 25A, 25B to be formed on the new street C of the workpiece W by the blades 21A, 21B, based on the correction values ​​Δy1, Δy2 input from the correction value determination unit 84.

[0098] The method for measuring the machining positions (machining quality) of grooves 25A, 25B formed by the meeting cutting method and the method for determining the correction values ​​Δy1, Δy2 are basically the same as those for the step cutting method described above. In this case, a machining quality measurement unit 83 measures the machining positions (groove center positions CL1, CL2) of each groove 25A, 25B based on the estimation results of an estimation unit 82 for each groove 25A, 25B. A correction value determination unit 84 determines the correction values ​​Δy1, Δy2 based on the machining positions of each groove 25A, 25B.

[0099] [Operation of the first embodiment] Figure 14 is a flowchart showing the flow of the cutting processing of the workpiece W by the dicing apparatus 10 of the first embodiment having the above-mentioned configuration, which corresponds to the control method of the workpiece processing apparatus of the present invention, and in particular the flow of the measurement processing of the processing quality (processing position) of the grooves 25A, 25B.

[0100] 14, when the workpiece W is sucked and held on the table 31, the movement control unit 72, photography control unit 74, and detection control unit 76 of the overall control unit 60 are activated. As a result, the movement control unit 72 drives the relative movement mechanism 49 to adjust the position of the microscope 23, and after this position adjustment, the microscope 23 photographs the alignment reference of the workpiece W under the control of the photography control unit 74, and further the detection control unit 76 performs alignment detection based on the photographed image of the alignment reference by the microscope 23 (step S1).

[0101] When the alignment detection is completed, the movement control unit 72 drives the relative movement mechanism 49 based on the alignment detection result to perform alignment between the street C to be machined and the blades 21A and 21B.

[0102] Next, the machining control unit 78 drives the spindles 22A, 22B and the relative movement mechanism 49 via the blade drive control unit 70 and the movement control unit 72, and the blades 21A, 21B cut the streets C using the meeting cutting method (see FIG. 6) or the step cutting method (see FIG. 7) (step S2). As a result, grooves 25A, 25B are formed along the streets C. Step S2 is repeated until measurement of the machining quality (here, the machining position) of the grooves 25A, 25B is started (NO in step S3). Note that after the first grooves 25A, 25B are formed, the process may proceed immediately to step S4.

[0103] When starting to measure the processing quality of the grooves 25A and 25B (YES in step S3), first, the measurement control unit 80 drives the relative movement mechanism 49 via the movement control unit 72 based on the known positions of the grooves 25A and 25B to adjust the position of the white interferometer 24 with respect to the grooves 25A and 25B (step S4). This allows the white interferometer 24 to be quickly adjusted to a position in the Z-axis direction where the measurement light L2 can be irradiated onto the grooves 25A and 25B and which corresponds to the initial step (first step) of the step scanning described above.

[0104] When the position adjustment of the white interferometer 24 is completed, the measurement control unit 80 operates the scan control unit 85 and the white interferometer 24 to start step scanning of the white interferometer 24 in the Z-axis direction (step S5, which corresponds to the scan control step of the present invention).

[0105] First, the measurement control unit 80 activates the white interferometer 24 (step S5A). This causes the white interferometer 24 to irradiate the grooves 25A and 25B with measurement light L2, and the imaging unit 56 outputs an interference signal L4 for each pixel to the interference signal acquisition unit 81. This causes the interference signal acquisition unit 81 to acquire the interference signal L4 for each pixel in the initial step (first step) of the step scan (step S5B, which corresponds to the interference signal acquisition step of the present invention).

[0106] Next, the scan control unit 85 drives the relative movement mechanism 49 (Z drive unit 48) to perform step movement, moving the white interferometer 24 in the Z-axis direction by a step width d (NO in step S5C, step S5D). This adjusts the position of the white interferometer 24 to the second step of the step scan. Then, the measurement control unit 80 operates the white interferometer 24 again (step S5A), and the interference signal acquisition unit 81 acquires the interference signal L4 for each pixel in the second step (step S5B).

[0107] Similarly, stepwise movement of the white interferometer 24 is repeatedly executed within the scanning range of the step scan, and at each step, operation of the white interferometer 24 and acquisition of the interference signal L4 for each pixel of the imaging unit 56 by the interference signal acquisition unit 81 are repeatedly executed (steps S5A to S5D). This ends the stepwise scan of the white interferometer 24 (YES in step S5C), and the interference signal acquisition unit 81 acquires the interference signal group L5 and outputs this interference signal group L5 to the estimation unit 82.

[0108] 10, the estimation unit 82 calculates the signal strength SG for each step of the step scan, calculates the peak strength SGM, and estimates the peak position Z0 for each pixel of the imaging unit 56 based on the interference signal group L5 (step S6, which corresponds to the estimation step of the present invention).The estimation results of the peak position Z0 for each pixel are output from the estimation unit 82 to the processing quality measurement unit 83.

[0109] By estimating the peak position Z0 for each pixel of the imaging unit 56 in this way, it is no longer necessary to perform vertical scanning of the white light interferometer 24 at a high sampling rate (fine pitch) that can reliably detect the peak position Z0, as in the conventional method. As a result, step scanning (vertical scanning at a low sampling rate) of the white light interferometer 24 can be performed.

[0110] Next, the processing quality measuring unit 83 generates either three-dimensional shape information 86 or cross-sectional shape information 88 of the grooves 25A, 25B as shown in Figures 11 and 12 based on the estimation result of the peak position Z0 for each pixel of the imaging unit 56 by the estimation unit 82. Furthermore, the processing quality measuring unit 83 calculates the workpiece-corresponding position coordinates described above based on the alignment detection result by the detection control unit 76 and the position coordinates of the white light interferometer 24 in the X and Y axis directions during vertical scanning.

[0111] Then, the machining quality measuring unit 83 calculates the machining positions (groove center positions CL1, CL2) of the grooves 25A, 25B as the machining quality of the grooves 25A, 25B, as shown in Fig. 13, based on at least one of the three-dimensional shape information 86 and the cross-sectional shape information 88 and the workpiece-corresponding position coordinates. This completes the measurement of the machining positions of the grooves 25A, 25B (kerf check) (step S7, corresponding to the machining quality measuring step of the present invention). The measurement results of the machining positions of the grooves 25A, 25B are output from the machining quality measuring unit 83 to the correction value determining unit 84, the memory unit 64, and the display unit 66.

[0112] As described above, in this embodiment, the processing quality of the grooves 25A and 25B is measured based on the estimation result of the peak position Z0 for each pixel of the imaging unit 56 by the estimation unit 82. Therefore, in this embodiment, the measurement accuracy of the processing quality of the grooves 25A and 25B is inferior to that of vertically scanning the white light interferometer 24 at a high sampling rate (fine pitch) as described in Patent Documents 3 and 4. However, the measurement accuracy of the processing quality of the grooves 25A and 25B required by the dicing device 10 is on the order of 1 μm, which is lower than the measurement accuracy required for surface roughness measurement, which requires measurement accuracy on the order of nm. Therefore, even if the white light interferometer 24 is step-scanned, the measurement performance of the processing quality of the grooves 25A and 25B does not deteriorate, and only the benefit of faster measurement due to step-scanning (low sampling) is obtained.

[0113] Furthermore, in this embodiment, the cross-sectional shapes of grooves 25A and 25B can be acquired using white light interferometer 24, and so the machining positions (machining quality) of grooves 25A and 25B can be measured without analyzing images of grooves 25A and 25B photographed by microscope 23 as in the conventional method. This makes it possible to accurately measure the machining position of groove 25B even when groove 25B is formed at the bottom of groove 25A, as in the step cut method, that is, even when it is difficult to determine the machining position of groove 25B based on the image photographed by microscope 23.

[0114] Furthermore, in this embodiment, it is possible to perform a kerf check on the groove 25B formed by the actual step cut method, without performing the step kerf check described above in which the groove 25B is formed by the narrow blade 21B in the uncut portion of the workpiece W. Therefore, it is possible to measure the machining position of the groove 25B with high precision.

[0115] When the measurement of the machining positions of the grooves 25A and 25B (kerf check) is completed, the correction value determination unit 84 determines the machining position correction values ​​Δy1 and Δy2 for each of the grooves 25A and 25B based on the measurement results of the machining positions of the grooves 25A and 25B (groove center positions CL1 and CL2) and the target values ​​for those machining positions (step S8), as shown in Fig. 13. Next, the correction value determination unit 84 outputs the determined correction values ​​Δy1 and Δy2 to the machining control unit 78.

[0116] Then, the machining control unit 78 drives the spindles 22A, 22B and the relative movement mechanism 49 via the blade drive control unit 70 and the movement control unit 72 based on the correction values ​​Δy1, Δy2 to perform cutting of the next and subsequent streets C by the meeting cutting method or the step cutting method (step S9). This allows cutting of each of the blades 21A, 21B at positions shifted by the correction values ​​Δy1, Δy2 in the Y-axis direction from the target positions (design positions) of the next and subsequent streets C. As a result, grooves 25A, 25B can be formed along the next and subsequent streets C with high precision.

[0117] [Effects of the first embodiment] As described above, in the dicing apparatus 10 of the first embodiment, the white interferometer 24 is step-scanned and the peak position Z0 of the white interferometer 24 is estimated for each pixel based on the interference signal group L5 acquired from the white interferometer 24, thereby enabling measurement of the processing quality of the grooves 25A and 25B using the white interferometer 24 in a short time. As described above, only the benefit of increased speed due to step scanning (low sampling) can be obtained without degrading the measurement performance of the processing quality of the grooves 25A and 25B.

[0118] In addition, in the first embodiment, step scanning of white interferometer 24 can be performed using relative movement mechanism 49 (Z carriage 44 and Z drive unit 48) of blade 21B, so there is no need to provide a separate dedicated scanning mechanism, and costs can be reduced. Furthermore, in the first embodiment, blade 21B and white interferometer 24 are integrally provided on Z carriage 44, so that the position of white interferometer 24 relative to grooves 25A and 25B (workpieces) can be adjusted using a conventional alignment detection method.

[0119] [Second embodiment] FIG. 15 is an explanatory diagram illustrating cutting of a workpiece W by a dicing apparatus 10 of a second embodiment and back-grinding of the workpiece W by a grinding (polishing) apparatus (not shown). In the first embodiment, each street C is completely cut (separated) when cutting the workpiece W by the dicing apparatus 10. In contrast, as shown by reference numeral XVA in FIG. 15, when cutting the workpiece W by the dicing apparatus 10 of the second embodiment, each street C is not completely cut by the blades 21A and 21B, but a certain amount of each street C is left uncut, thereby forming half-cut grooves 90A and 90B (corresponding to the processed portion). Note that the half-cut groove 90A formed by the blade 21A and the half-cut groove 90B formed by the blade 21B have substantially the same shape.

[0120] Then, as shown by symbol XVB in Figure 15, the back surface of the workpiece W is ground using a grinding device separate from the dicing device 10 to remove any remaining cut portions, thereby completely cutting each street C as shown by symbol XVC in Figure 15.

[0121] When half-cutting each street C using the dicing device 10 in this manner, if the processing depth (also referred to as the cutting depth or the milling depth) of the street C by the blades 21A and 21B is insufficient, the workpiece W cannot be cut even after back-grinding, resulting in poor cutting. Conversely, if the blades 21A and 21B cut the street C too deeply, the workpiece W will crack before back-grinding. Therefore, if the cutting depth accuracy of the blades 21A and 21B is low, the yield will decrease, especially in the production of devices with a thin total thickness (processing of a thin workpiece W).

[0122] Furthermore, the diameter of the blades 21A and 21B changes due to wear, and their height position in the Z-axis direction changes due to temperature changes. Therefore, it is important to highly accurately control the machining depth of the blades 21A and 21B in the Z-axis direction for each street C (workpiece W).

[0123] Therefore, in the dicing apparatus 10 of the second embodiment, the machining depths cz1, cz2 (see FIG. 16) of the half-cut grooves 90A, 90B formed in the workpiece W are measured using a white light interferometer 24. In the second embodiment, the machining widths cy1, cy2 (see FIG. 16) of the half-cut grooves 90A, 90B are also measured simultaneously with the machining depths cz1, cz2. Here, the machining widths cy1, cy2 and machining depths cz1, cz2 of the half-cut grooves 90A, 90B correspond to the machining quality (machined shape) of the machined portion in this invention.

[0124] The dicing apparatus 10 of the second embodiment has basically the same configuration as the dicing apparatus 10 of the first embodiment, so the same functions or configurations as those of the first embodiment are given the same reference numerals and descriptions thereof will be omitted.

[0125] The machining control unit 78 of the second embodiment drives the spindles 22A, 22B and the relative movement mechanism 49 via the blade drive control unit 70 and the movement control unit 72, and cuts each street C of the workpiece W by simultaneous machining processing with the blades 21A, 21B using the meeting cutting method. As a result, half-cut grooves 90A, 90B are formed for every two streets C.

[0126] The measurement control unit 80 and the scan control unit 85 of the second embodiment control the white interferometer 24 and the relative movement mechanism 49 to perform position adjustment of the white interferometer 24, step scanning of the white interferometer 24, and operation for each step, for each half-cut groove 90A, 90B. As a result, the interference signal acquisition unit 81 of the second embodiment acquires an interference signal group L5 from the white interferometer 24 for each half-cut groove 90A, 90B, and the estimation unit 82 of the second embodiment estimates the peak position Z0 for each pixel of the imaging unit 56.

[0127] 16 is an explanatory diagram for describing shape measurement of the cross-sectional shapes of the half-cut grooves 90A, 90B along the Y-axis direction by the processing quality measuring unit 83 of the second embodiment. As shown in Fig. 16, the processing quality measuring unit 83 of the second embodiment generates cross-sectional shape information 88 of each of the half-cut grooves 90A, 90B, similarly to the first embodiment, based on the estimation result of the peak position Z0 for each pixel of the imaging unit 56 by the estimating unit 82.

[0128] Next, based on the cross-sectional shape information 88 of the half-cut grooves 90A and 90B, the machining quality measurement unit 83 calculates the machining width cy1 and machining depth cz1 of the half-cut groove 90A and the machining width cy2 and machining depth cz2 of the half-cut groove 90B as the machining quality (machined shape) of the half-cut grooves 90A and 90B. Here, the machining depths cz1 and cz2 are the depths of the half-cut grooves 90A and 90B in the Z-axis direction at the centers of the machining widths cy1 and cy2, respectively. Note that the machining depths cz1 and cz2 may also be the depths to the lowest points of the half-cut grooves 90A and 90B in the Z-axis direction. The machining quality measurement unit 83 then outputs the measurement results of the machining depths cz1 and cz2 for each half-cut groove 90A and 90B to the correction value determination unit 84, the memory unit 64, and the display unit 66.

[0129] The correction value determination unit 84 of the second embodiment determines a correction value Δz1 for the machining depth cz1 corresponding to the blade 21A and a correction value Δz2 for the machining depth cz2 corresponding to the blade 21B based on the measurement results of the machining depths cz1 and cz2 by the machining quality measurement unit 83 and the target values ​​tz for the machining depths cz1 and cz2 of the half-cut grooves 90A and 90B corresponding to the type of workpiece W.

[0130] Furthermore, the correction value determination unit 84 outputs the determined correction values ​​Δz1, Δz2 to the machining control unit 78. As a result, the machining control unit 78 controls the relative movement mechanism 49 and the like based on the correction values ​​Δz1, Δz2 input from the correction value determination unit 84, and corrects the machining depths cz1, cz2 of the half-cut grooves 90A, 90B to be formed on the new street C of the workpiece W by the blades 21A, 21B.

[0131] The flow of the cutting processing of the workpiece W by the dicing apparatus 10 of the second embodiment, particularly the flow of the measurement processing of the processing quality (processing depths cz1, cz2) of the half-cut grooves 90A, 90B, is basically the same as the flow of the cutting processing of the first embodiment shown in Figure 14 above, so a detailed explanation will be omitted here.

[0132] As described above, the same effects as those of the first embodiment can be obtained in the dicing apparatus 10 of the second embodiment by performing step scanning with the white interferometer 24. Furthermore, since the cross-sectional shapes of the half-cut grooves 90A, 90B can be measured with high precision using the white interferometer 24, the processing depths cz1, cz2 (processing quality) can be measured with high precision based on the measurement results.

[0133] Furthermore, since the machining depths cz1, cz2 can be measured during cutting of the workpiece W by the blades 21A, 21B, accurate correction values ​​Δz1, Δz2 can be immediately applied to cutting of the next or subsequent streets C. Furthermore, since the correction values ​​Δz1, Δz2 can be determined each time cutting of one line of streets C is performed, the machining accuracy of the machining depths cz1, cz2 for each blade 21A, 21B can be further improved.

[0134] [Third embodiment] In each of the above embodiments, the processing quality of the processed portion such as grooves 25A, 25B and half-cut grooves 90A, 90B is measured, and based on the measurement results, corrections are made to the cutting processing of the workpiece W by blades 21A, 21B. In contrast, in dicing device 10 of the third embodiment, the tip shapes of blades 21A, 21B are measured based on the measurement results of the processing quality of the processed portion by blades 21A, 21B.

[0135] Figure 17 is a functional block diagram of the overall control unit 60 of the dicing apparatus 10 of the third embodiment. As shown in Figure 17, the dicing apparatus 10 of the third embodiment has basically the same configuration as the dicing apparatus 10 of each of the above embodiments, except that the overall control unit 60 functions as the blade shape measuring unit 100 instead of the correction value determining unit 84. For this reason, parts that are the same in function or configuration as those of the above embodiments are given the same reference numerals, and their description will be omitted.

[0136] As in the second embodiment, the machining control unit 78 of the third embodiment drives each spindle 22A, 22B and the relative movement mechanism 49 via the blade drive control unit 70 and the movement control unit 72 to form half-cut grooves 90A, 90B (see Figure 15) for each street C.

[0137] The measurement control unit 80, scan control unit 85, interference signal acquisition unit 81, estimation unit 82, and processing quality measurement unit 83 of the third embodiment function in the same manner as in the second embodiment. As a result, for each half-cut groove 90A, 90B, the position adjustment of the white interferometer 24, step scanning of the white interferometer 24 and operation for each step, acquisition of the interference signal group L5, estimation of the peak position Z0, and shape measurement of the cross-sectional shape are performed.

[0138] 18 is an explanatory diagram for illustrating shape measurement of the cross-sectional shapes of the half-cut grooves 90A, 90B by the processing quality measuring unit 83 of the third embodiment. As shown in Fig. 18, the processing quality measuring unit 83 of the third embodiment generates cross-sectional shape information 88 of each of the half-cut grooves 90A, 90B based on the estimation result of the estimating unit 82, as in the second embodiment, and outputs the cross-sectional shape information 88 for each of the half-cut grooves 90A, 90B to the blade shape measuring unit 100.

[0139] The blade shape measuring unit 100 measures the tip shapes of the blades 21A and 21B based on the measurement results (cross-sectional shape information 88) of the cross-sectional shapes of the half-cut grooves 90A and 90B input from the processing quality measuring unit 83. Because the tip shapes of the blades 21A and 21B are transferred to the bottoms of the half-cut grooves 90A and 90B, respectively, it is possible to measure the tip shapes of the blades 21A and 21B from the cross-sectional shapes of the half-cut grooves 90A and 90B. The measurement results of the tip shapes of the blades 21A and 21B by the blade shape measuring unit 100 are stored in the memory unit 64 and displayed on the display unit 66.

[0140] [Operation of the third embodiment] 19 is a flowchart showing the flow of a process for measuring the tip shapes of blades 21A, 21B by dicing apparatus 10 of the third embodiment, which corresponds to a method for controlling a workpiece processing apparatus of the present invention. As shown in Fig. 19, similar to the first embodiment (see Fig. 14), alignment detection (step S1) and cutting of each street C by the meeting cutting method (step S2) are performed, and half-cut grooves 90A, 90B are formed along each street C.

[0141] When starting measurement of the tip shape of the blades 21A, 21B (YES in step S3A), steps S4 to S7A are executed as in the first embodiment. That is, for each half-cut groove 90A, 90B, the position of the white interferometer 24 is adjusted (step S4), the white interferometer 24 is subjected to step scanning (step S5), and the peak position Z0 is estimated (step S6). Then, the processing quality measurement unit 83 measures the cross-sectional shapes of the half-cut grooves 90A, 90B (generates cross-sectional shape information 88) based on the estimation result of the peak position Z0 for each half-cut groove 90A, 90B by the estimation unit 82 (step S7A).

[0142] Next, the blade shape measuring unit 100 measures the tip shapes of the blades 21A and 21B based on the cross-sectional shape information 88 of the half-cut grooves 90A and 90B, and outputs the measurement results of the tip shapes of each of the blades 21A and 21B to the storage unit 64 and the display unit 66 (step S10). As a result, the measurement results of the tip shapes of the blades 21A and 21B are stored in the storage unit 64 and displayed on the display unit 66.

[0143] The operator determines the wear state of each of the blades 21A, 21B based on the measurement results of the tip shapes of the blades 21A, 21B displayed on the display unit 66, and determines whether or not the blades 21A, 21B need to be replaced, etc. Note that the determination of the wear state of each of the blades 21A, 21B and whether or not replacement, etc. is necessary may be automatically performed by the integrated control unit 60.

[0144] As described above, in the dicing apparatus 10 of the third embodiment, step scanning of the white interferometer 24 is performed, thereby enabling measurement of the cross-sectional shapes (processing quality) of the half-cut grooves 90A, 90B in a short time using the white interferometer 24. As a result, measurement of the tip shapes of the blades 21A, 21B can be performed in a short time.

[0145] Furthermore, since the cross-sectional shapes of the half-cut grooves 90A, 90B can be measured with high precision using the white light interferometer 24, the state of wear of the tip shapes of the blades 21A, 21B and the progress of that wear can be determined with high precision. This makes it possible to prompt the operator to replace, truing (correcting the shape of the blades 21A, 21B) or dressing (sharpening and re-sharpening the blades 21A, 21B) the blades 21A, 21B before the machining quality of the workpiece W falls below the tolerance and a defect occurs.

[0146] Furthermore, with the dicing apparatus 10 of the third embodiment, it is possible to measure the tip shapes of the blades 21A, 21B while the blades 21A, 21B are cutting the workpiece W. As a result, the productivity of the dicing apparatus 10 can be improved compared to conventional methods.

[0147] [Fourth embodiment] Fig. 20 is an explanatory diagram for explaining step scanning of the white light interferometer 24 by the dicing apparatus 10 of the fourth embodiment. Fig. 21 is an enlarged view of the grooves 25A and 25B in Fig. 20 and is a diagram for explaining the position of the reference focal point FP of the measurement light L2 for each step of the step scanning of the fourth embodiment. Note that Figs. 20 and 21 will be explained using an example in which the grooves 25A and 25B are formed by the step cut method.

[0148] In the dicing apparatus 10 of each of the above embodiments, the step width d for each step of the step scanning of the white light interferometer 24 is constant, but the dicing apparatus 10 of the fourth embodiment has a function of individually adjusting the step width d for each step of the step scanning. Note that the dicing apparatus 10 of the fourth embodiment has basically the same configuration as the dicing apparatus 10 of each of the above embodiments, and therefore, components that are the same in function or configuration as those of the above embodiments will be assigned the same reference numerals and their description will be omitted.

[0149] In the fourth embodiment, the step width d for each step of the step scan of the white interferometer 24 is set in the scan control unit 85 via the operation unit 62 etc. This allows the scan control unit 85 to arbitrarily adjust the step width d for each step of the step scan.

[0150] 20 and 21, in the fourth embodiment, the scanning range of the step scan of the white interferometer 24 is divided into a first scanning range SR1, a second scanning range SR2, and a third scanning range SR3 according to the locations of the grooves 25A and 25B (locations of the workpiece). The first scanning range SR1 is a scanning range in which the reference focusing point FP of the measurement light L2 emitted from the white interferometer 24 scans the front surface of the workpiece W and the bottom of the groove 25A. The second scanning range SR2 is a scanning range in which the reference focusing point FP scans the bottom of the groove 25B. The third scanning range SR3 is a scanning range between the first scanning range SR1 and the second scanning range SR2.

[0151] When the grooves 25A and 25B are formed by the meeting cutting method, the first scanning range SR1 is a scanning range in which the reference condensing point FP scans the front surface of the workpiece W. The second scanning range SR2 is a scanning range in which the reference condensing point FP scans the bottom of the groove 25A or 25B.

[0152] In the fourth embodiment, the step width d of each step of the step scan is set narrow in the ranges corresponding to the first scanning range SR1 and the second scanning range SR2, and conversely, the step width d of each step is set wide in the range corresponding to the third scanning range SR3. This allows the white interferometer 24 to perform step scans at a high sampling rate in areas important for measuring the machining quality of the grooves 25A and 25B (the front surface of the workpiece W and the bottoms of the grooves 25A and 25B), thereby further improving the measurement accuracy of the machining quality of the grooves 25A and 25B. Conversely, for areas that do not significantly affect the measurement of the machining quality of the grooves 25A and 25B, the white interferometer 24 performs step scans at a low sampling rate, thereby enabling the measurement of the machining quality of the grooves 25A and 25B to be completed in a shorter time. As a result, the measurement of the machining quality of the grooves 25A and 25B can be completed in a shorter time with high accuracy.

[0153] 20 and 21, the step width d of each of the scanning ranges SR1 to SR3 can be adjusted arbitrarily, for example, the step width d may be different for each of the scanning ranges SR1 to SR3. Also, the scanning range of the step scan may be divided into two or four or more depending on the type of grooves 25A, 25B (workpieces).

[0154] [others] In each of the above embodiments, the dicing device 10 is provided with a pair of blades 21A, 21B and a pair of spindles 22A, 22B, but the number of blades and spindles (i.e., the number of processing heads of the present invention) may be one or three or more.

[0155] In each of the above embodiments, a twin-spindle dicer (a pair of blades 21A, 21B and a pair of spindles 22A, 22B) has been used as an example of the processing head of the present invention, but the present invention can also be applied when the dicing device 10 is provided with one or more laser processing heads that perform laser processing (including ablation groove processing) on ​​the workpiece W.

[0156] In each of the above embodiments, white interferometer 24 is provided on one of the pair of Z carriages 44 (one of the twin spindles) and microscope 23 is provided on the other of the pair of Z carriages 44 (the other of the twin spindles), but white interferometer 24 may also be provided on the other of the pair of Z carriages 44 (the other of the twin spindles). Similarly, microscope 23 may also be provided on one of the Z carriages 44. In other words, a microscope 23 and a white interferometer 24 may be provided for each of a plurality of Z carriages 44. Furthermore, in each of the above embodiments, Z carriage 44 performs the above-described step scanning by stepping white interferometer 24 in the Z axis direction, but it is only necessary that white interferometer 24 can be step-scanned relative to table 31; for example, step scanning may be performed by stepping table 31 in the Z axis direction.

[0157] In each of the above embodiments, the white interferometer 24 is provided on the Z carriage 44, so that the blade 21B and the white interferometer 24 are scanned together in the Z-axis direction, but the white interferometer 24 may be provided separately from the blade 21B and the Z carriage 44. In this case, a separate actuator (carriage) is provided that can scan the white interferometer 24 in the Z-axis direction.

[0158] In each of the above embodiments, the white light interferometer 24 is used to measure the processing quality [processing position, processing shape (including cross-sectional shape)] of various processed parts such as grooves 25A, 25B and half-cut grooves 90A, 90B formed in the workpiece W by blades 21A, 21B, but the processing quality of processed parts formed in the workpiece W by other devices may also be measured by the dicing device 10.

[0159] For example, if the workpiece W is a laminate in which a low-k film or the like is laminated on a silicon substrate, the workpiece W is subjected to a laser processing process using a laser beam for each street C by a laser processing device (not shown). As a result, a laser groove is formed for each street C. Then, the dicing device 10 uses a white light interferometer 24 to measure the processing quality of the laser groove (center position of the processing width), and based on the measurement results, the bottom of each laser groove is cut by a simultaneous processing process using blades 21A and 21B using a meeting cutting method.

[0160] In each of the above embodiments, the dicing device 10 is provided with a Mirau-type white light interferometer 24, but various types of known white light interferometers 24, such as a Michelson-type or Fizeau-type, may also be provided.

[0161] The dicing apparatus 10 of each of the above embodiments may be combined as appropriate. For example, the dicing apparatus 10 of the first embodiment and the dicing apparatus 10 of the second embodiment may be combined to simultaneously measure both the processing position and the processing shape as the processing quality of various processed portions. Furthermore, the dicing apparatus 10 of the first and second embodiments may be combined with the dicing apparatus 10 of the third embodiment as appropriate to enable both the processing quality of various processed portions and measurement of the tip shapes of the blades 21A and 21B to be performed.

[0162] In each of the above embodiments, the measurement of the processing quality of grooves 25A, 25B and half-cut grooves 90A, 90B as the processed parts of the present invention has been described as an example, but the present invention can also be applied to measuring the processing quality of various processed parts formed in the workpiece W by the dicing device 10 or other devices. [Explanation of symbols]

[0163] 10... dicing device, 21A, 21B... blade, 22A, 22B... spindle, 23... microscope, 24... white light interferometer, 25A, 25B... groove, 31... table, 49... relative movement mechanism, 51... white light source, 56... imaging unit, 60... overall control unit, 70... blade drive control unit, 72... movement control unit, 74... photography control unit, 76... detection control unit, 78... processing control unit, 80... measurement control unit, 81... interference signal acquisition unit, 82... estimation unit, 83... processing quality Measurement unit, 84...correction value determination unit, 86...three-dimensional shape information, 88...cross-sectional shape information, 90A, 90B...half-cut groove, 100...blade shape measurement unit, C...street, CL1, CL2...groove center position, cy1, cy2...machining width, cz1, cz2...machining depth, FP...reference focusing point, L1...white light, L2...measurement light, L3...reference light, L4...interference signal, L5...interference signal group, W...workpiece, Δy1, Δy2, Δz1, Δz2...correction value, Z0...peak position

Claims

1. a table for holding a flat workpiece; a machining head that processes the workpiece held on the table; a relative movement mechanism that moves the processing head relative to the table; a machining control unit that drives the machining head and the relative movement mechanism to form a machined portion on the workpiece by the machining head; a white interferometer provided integrally with the processing head, which emits white light toward the processed portion formed on the workpiece and detects, for each pixel, an interference signal between the white light reflected by the processed portion and the white light reflected by a reference surface; a scanning control unit that drives the relative movement mechanism to relatively scan the processing head and the white light interferometer together in a direction perpendicular to the table, thereby changing the optical path length of the white light reflected by the processed portion; a measurement control unit that operates the white light interferometer and the scan control unit at a position where the white light can be irradiated onto the workpiece; an interference signal acquisition unit that intermittently acquires the interference signal for each pixel from the white interferometer during the scanning; an estimation unit that estimates, for each pixel, a position of the white interferometer at which the intensity of the interference signal peaks, based on the interference signal for each pixel acquired by the interference signal acquisition unit; a machining quality measuring unit that measures at least one of a machining position and a machining shape of the workpiece as the machining quality of the workpiece based on the estimation result of the estimating unit; Equipped with The machining heads include a first machining head and a second machining head, The processing control unit a first machining process of driving the relative movement mechanism and the first machining head to form a first groove as the machined portion in the workpiece; a second machining process in which the relative movement mechanism and the second machining head are driven to form a second groove at the bottom of the first groove as the machined portion and cut the workpiece; A workpiece processing device that performs the above.

2. 2. The workpiece processing device according to claim 1, wherein the measurement control unit drives the relative movement mechanism to relatively move the white interferometer to a position where the white light can be irradiated onto the workpiece, based on a known position of the workpiece formed by the processing head.

3. a correction value determination unit that determines a correction value for correcting at least one of the machining position and the machining shape of the workpiece based on the measurement result of the machining quality measurement unit; 3. The workpiece machining device according to claim 1, wherein the machining control unit drives the machining head and the relative movement mechanism based on the compensation value determined by the compensation value determination unit to form the machined portion on the workpiece.

4. 4. The workpiece processing device according to claim 1, wherein the processing head cuts the workpiece with a rotating disk-shaped blade.

5. The processing head cuts the workpiece with a rotating disk-shaped blade, the processing quality measuring unit measures a cross-sectional shape of the processed portion as the processing quality; The workpiece machining device according to claim 1 , further comprising a blade shape measuring unit that measures a tip shape of the blade based on a measurement result of the cross-sectional shape by the machining quality measuring unit.

6. a machining control step of driving a machining head that processes a flat workpiece held on a table and a relative movement mechanism that moves the machining head relative to the table, thereby forming a machined portion on the workpiece with the machining head; a scanning control step of scanning a white interferometer, which emits white light toward the workpiece and detects an interference signal between the white light reflected by the workpiece and the white light reflected by a reference surface, for each pixel, along a direction perpendicular to the table, together with the processing head, to change the optical path length of the white light reflected by the workpiece; an interference signal acquiring step of intermittently acquiring the interference signal for each pixel from the white light interferometer during the scanning; an estimation step of estimating, for each pixel, a position of the white light interferometer at which the intensity of the interference signal peaks, based on the interference signal for each pixel acquired in the interference signal acquisition step; a processing quality measuring step of measuring at least one of a processing position and a processing shape of the workpiece as the processing quality of the workpiece based on the estimation result of the estimation step; and In a case where the machining head includes a first machining head and a second machining head, the machining control step a first machining process of driving the relative movement mechanism and the first machining head to form a first groove as the machined portion in the workpiece; a second machining process in which the relative movement mechanism and the second machining head are driven to form a second groove at the bottom of the first groove as the machined portion and cut the workpiece; A method for controlling a workpiece processing device that executes the above.

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