Measurement tool, operation accuracy measurement system, and operation accuracy measurement method

Abstract

To measure operation accuracy of a linear moving mechanism in a short time with high accuracy.SOLUTION: The present invention relates to an operation accuracy measurement method for measuring operation accuracy of a linear moving mechanism of a device which comprises a support table, a work unit and the linear moving mechanism linearly moving the work unit and the support table relatively in a feed direction. The operation accuracy measurement method includes: mounting on the support table a measurement tool which has a plane bottom face, a parallel face opposed to the bottom face and also parallel with the bottom face, and an inclined face connected to the parallel face through a linear border line and inclined to the parallel face; adjusting a direction of the measurement tool so that the border line is parallel with the feed direction and also adjusting positions of the measurement tool and a white interferometer so that the white interferometer can observe the parallel face and the inclined face simultaneously; observing the parallel face and the inclined face by the white interferometer while linearly moving the support table and the work unit relatively in the feed direction and observing changes of interference fringes; and finding out the operation accuracy of the linear moving mechanism from the observed changes of the interference fringes.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a measuring tool, an operation accuracy measuring system, and an operation accuracy measuring method for measuring the operation accuracy of a linear motion mechanism that moves a part linearly. [Background technology]

[0002] Device chips equipped with semiconductor devices are formed from semiconductor wafers, package substrates, ceramic substrates, glass substrates, etc. Individual device chips can be formed by setting a plurality of intersecting planned division lines on the surface of a semiconductor wafer or the like, forming semiconductor devices in each area partitioned by the planned division lines, and then dividing the semiconductor wafer or the like along the planned division lines.

[0003] For example, a cutting device is used to divide a semiconductor wafer or the like. The cutting device includes a chuck table (support table) that suction-holds a workpiece such as a semiconductor wafer, and a cutting unit that cuts the workpiece held on the chuck table. The chuck table is supported by a table base. The cutting unit has an annular cutting blade.

[0004] When cutting the workpiece, the cutting device rotates the cutting blade in a plane perpendicular to the surface of the workpiece and moves the cutting unit and the chuck table relatively along the processing feed direction to cause the cutting blade to cut into the workpiece along the planned dividing line. After that, in order to cut the workpiece along another planned dividing line, the cutting unit and the chuck table are moved relatively in an indexing feed direction perpendicular to the processing feed direction.

[0005] The cutting device includes various moving mechanisms for relatively moving the cutting unit and the chuck table, more specifically, linear movement mechanisms such as a processing feed unit that moves the chuck table or the like in a processing feed direction and an indexing feed unit that moves the chuck table or the like in an indexing feed direction.

[0006] In a cutting device, unless these linear motion mechanisms operate properly, the workpiece cannot be subjected to a predetermined cutting process, and therefore it is desirable to measure the operation accuracy of each linear motion mechanism, that is, pitching and yawing. When measuring the operation accuracy of the linear motion mechanism, a measuring jig is used to measure pitching and yawing in the vicinity of the processing point where the cutting blade contacts the workpiece during cutting (see Patent Document 1). This measuring jig is attached to the cutting unit before use. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2017-199777 A Summary of the Invention [Problem to be solved by the invention]

[0008] When using this measuring jig, the mounting position of the measuring jig must be changed every time the measurement item such as pitching and yawing is changed. This work of changing the mounting position is performed by an operator, which is a factor that takes time to measure the operational accuracy of a linear motion mechanism. In addition, rolling is also one of the measurement items of operational accuracy that is desired to be measured in addition to pitching and yawing, but this measuring jig cannot be used to measure rolling.

[0009] The present invention has been made in consideration of these problems, and its object is to provide a measuring jig, an operational accuracy measurement system, and an operational accuracy measurement method for measuring the operational accuracy of a linear motion mechanism with high precision in a short period of time. [Means for solving the problem]

[0010] According to one aspect of the present invention, a semiconductor device has a flat bottom surface, a parallel surface facing the bottom surface and parallel to the bottom surface, and an inclined surface connected to the parallel surface via a linear boundary line and inclined with respect to the parallel surface, The inclined surface is made of a metal material, and the inclination of the inclined surface with respect to the parallel surface is 1 / 15000 or more and 1 / 5000 or less, and the bottom surface, the parallel surface and the inclined surface are eachThe interference fringes based on the light reflected on the parallel surface and the inclined surface can be observed by an interferometer. It is as flat as A measurement tool is provided that is characterized by the above features.

[0012] According to another aspect of the present invention, there is provided an operational accuracy measurement system for measuring the operational accuracy of a linear movement mechanism in an apparatus including a support table having a support surface and supporting an object, a work unit that performs either a processing or measurement operation on the object supported by the support table, and a linear movement mechanism that moves the work unit and the support table relatively linearly along a feed direction, the system comprising: a white interferometer that is capable of observing a work point on the support table where the work unit performs work on the object, and is connected to the work unit so as to be movable in a direction perpendicular to the feed direction; a planar bottom surface; a measuring jig having a parallel surface facing the bottom surface and parallel to the bottom surface, and an inclined surface connected to the parallel surface via a linear boundary line and inclined with respect to the parallel surface, the boundary line being oriented in a direction parallel to the feed direction, and the measuring jig being positioned in a position where the parallel surface and the inclined surface can be simultaneously observed within an observation range of the white light interferometer, the measuring jig being placed on the support table or on a table base that can support the support table, and the linear movement mechanism is operated to relatively move the working unit and the measuring jig linearly in the feed direction while observing changes in the interference fringes of the parallel surface and the inclined surface of the measuring jig with the white light interferometer, determining yawing accuracy based on a maximum change in the inclination of the interference fringes, determining pitching accuracy based on a maximum change in the brightness of the interference fringes, or determining rolling accuracy by observing the occurrence or non-occurrence of interference fringes on the parallel surfaces or changes in the spacing of the interference fringes on the inclined surfaces, There is provided an operation accuracy measuring system that determines the operation accuracy of the linear motion mechanism based on the change in the interference fringes.

[0013] Preferably, the gradient of the inclined surface of the measuring jig with respect to the parallel surface is not less than 1 / 15000 and not more than 1 / 5000.

[0014] According to yet another aspect of the present invention, there is provided an operation accuracy measurement method for measuring the operation accuracy of a linear movement mechanism in an apparatus including a support table having a support surface and supporting an object, an operation unit that performs either a machining or measuring operation on the object supported by the support table, and a linear movement mechanism that relatively moves the operation unit and the support table linearly along a feed direction, the method comprising the steps of: placing a measuring tool having a planar bottom surface, a parallel surface facing the bottom surface and parallel to the bottom surface, and an inclined surface connected to the parallel surface via a linear boundary line and inclined relative to the parallel surface, on the support table or on a table capable of supporting the support table; a placing step of placing the measuring jig on a base; an adjustment step of adjusting the orientation of the measuring jig so that the boundary line of the measuring jig is parallel to the feed direction and adjusting the positions of the measuring jig and the white light interferometer so that the parallel surface and the inclined surface can be observed simultaneously with the white light interferometer connected to the working unit; an interference fringe observation step of observing the parallel surface and the inclined surface with the white light interferometer while linearly moving the working unit and the measuring jig relatively in the feed direction by the linear movement mechanism, and observing changes in the interference fringes; and an operation accuracy determination step of determining the operation accuracy of the linear movement mechanism from the observed changes in the interference fringes. In the operation accuracy determination step, the yawing accuracy of the operation accuracy is determined based on the maximum change in the inclination of the interference fringes on the inclined surface observed while the operation unit and the measuring tool move relative to each other, the pitching accuracy of the operation accuracy is determined based on the maximum change in the brightness of the interference fringes observed while the operation unit and the measuring tool move relative to each other, or the rolling accuracy of the operation accuracy is determined based on the presence or absence of interference fringes on the parallel surface observed while the operation unit and the measuring tool move relative to each other, or the change in the fringe spacing of the interference fringes on the inclined surface. The present invention provides a method for measuring operation accuracy.

[0016] Also, preferably, the gradient of the inclined surface of the measuring jig with respect to the parallel surface is not less than 1 / 15000 and not more than 1 / 5000. Effect of the Invention

[0017] In a measuring jig, an operational accuracy measuring system, and an operational accuracy measuring method according to one aspect of the present invention, the measuring jig has a planar bottom surface, a parallel surface facing the bottom surface and parallel to the bottom surface, and an inclined surface connected to the parallel surface via a linear boundary line and inclined with respect to the parallel surface. When determining the operational accuracy of a linear movement mechanism that moves a support table and a working unit relatively linearly, the measuring jig is placed on the support table or on a table base that can support the support table. Then, the linear movement mechanism is operated while observing the upper surface of the measuring jig with a white light interferometer connected to the working unit.

[0018] At this time, the operational accuracy of the linear motion mechanism can be measured with high precision based on the change in the interference fringes observed by the white light interferometer on the parallel plane and the inclined plane. For example, it is possible to evaluate not only yawing and pitching but also rolling. Here, this measuring jig does not need to be repositioned on the support table when changing the measurement item of operational accuracy, and each measurement item of operational accuracy can be evaluated simultaneously by simply operating the linear motion mechanism once. In other words, by using the measuring jig together with the white light interferometer, the operational accuracy of the linear motion mechanism can be measured quickly.

[0019] Therefore, according to one aspect of the present invention, a measuring tool, an operation accuracy measuring system, and an operation accuracy measuring method are provided for measuring the operation accuracy of a linear motion mechanism with high accuracy in a short period of time. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a perspective view showing a cutting device. [Diagram 2] FIG. 2 is a perspective view showing a schematic diagram of a measuring jig. [Diagram 3] FIG. 2 is a perspective view showing a cutting unit (working unit) and a measuring jig. [Figure 4] FIG. 2 is a side view showing a schematic diagram of an optical system of a white light interferometer. [Diagram 5] FIG. 5(A) is a photograph simulating an example of interference fringes, FIG. 5(B) is a photograph simulating another example of interference fringes, FIG. 5(C) is a photograph simulating yet another example of interference fringes, and FIG. 5(D) is a photograph simulating yet another example of interference fringes. [Figure 6] 4 is a flowchart showing the flow of each step of a method for measuring the operational accuracy of a linear motion mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] An embodiment according to one aspect of the present invention will be described with reference to the accompanying drawings. First, an apparatus in which a measuring tool according to this embodiment is used will be described. The apparatus in which the measuring tool is used is, for example, a processing apparatus that performs a predetermined processing on a workpiece, or a measuring apparatus that measures the characteristics of a sample by a predetermined method. Below, an example will be described in which the apparatus is a cutting apparatus that cuts a workpiece, but the apparatus is not limited to a cutting apparatus.

[0022] FIG. 1 shows a cutting device (apparatus) 2 that cuts a workpiece such as a substantially circular disk-shaped substrate made of a material such as silicon, silicon carbide (SiC), gallium arsenide (GaAs), or other semiconductor material, or a material such as sapphire, glass, or quartz.

[0023] A number of devices such as ICs (Integrated Circuits) are formed on the surface of the workpiece. Finally, the workpiece is divided into individual devices to form individual device chips. For example, the workpiece is cut while attached to a tape stretched over a circular frame.

[0024] 1, the cutting device 2 is equipped with a device base 4 that supports each of the components. An X-axis moving table 6, a processing feed unit that moves the X-axis moving table 6 in the X-axis direction (processing feed direction), and a drainage channel 20 that covers the processing feed unit are provided at the central upper part of the device base 4. The processing feed unit is equipped with a pair of X-axis guide rails 12 that are parallel to the X-axis direction, and the X-axis moving table 6 is slidably attached to the X-axis guide rails 12.

[0025] A nut portion (not shown) is provided on the underside of the X-axis moving table 6, and an X-axis ball screw 14 parallel to the X-axis guide rail 12 is screwed into this nut portion. An X-axis pulse motor 16 is connected to one end of the X-axis ball screw 14. When the X-axis pulse motor 16 rotates the X-axis ball screw 14, the X-axis moving table 6 moves in the X-axis direction along the X-axis guide rail 12.

[0026] For example, a table base 8b is provided on the X-axis moving table 6, and a chuck table (support table) 8 for sucking and holding the workpiece is provided on the table base 8b. However, the chuck table 8 may be provided directly on the X-axis moving table 6. The chuck table 8 (table base 8b) is connected to a rotary drive source (not shown) such as a motor, and is rotatable around a rotation axis perpendicular to the upper surface of the chuck table 8. The chuck table 8 (table base 8b) is fed in the X-axis direction by the above-mentioned processing feed unit.

[0027] The surface (upper surface) of the chuck table 8 serves as a holding surface 8a that sucks and holds the workpiece. This holding surface 8a is connected to a suction source (not shown) via a flow path (not shown) formed inside the chuck table 8. Clamps 10 are disposed around the holding surface 8a for fixing an annular frame that holds the workpiece via a tape.

[0028] A support structure 22 that supports two cutting units (working units) 18 that cut the workpiece is disposed across the processing feed unit on the upper surface of the device base 4. An indexing feed unit that moves the two cutting units 18 in the Y-axis direction (indexing feed direction) and a cutting feed unit that moves them in the Z-axis direction (cutting feed direction) are provided on the upper front surface of the support structure 22.

[0029] A pair of Y-axis guide rails 24 parallel to the Y-axis direction are provided on the front surface of the support structure 22. Two Y-axis moving plates 26 corresponding to the cutting units 18, respectively, are slidably attached to the Y-axis guide rails 24. A nut portion (not shown) is provided on the back surface side (rear surface side) of each of the Y-axis moving plates 26, and a Y-axis ball screw 28 parallel to the Y-axis guide rails 24 is screwed into this nut portion.

[0030] A Y-axis pulse motor 28a is connected to one end of the Y-axis ball screw 28. When the Y-axis ball screw 28 is rotated by the Y-axis pulse motor 28a, the corresponding Y-axis moving plate 26 moves in the Y-axis direction along the Y-axis guide rail 24. In other words, the Y-axis guide rail 24, the Y-axis moving plate 26, the Y-axis ball screw 28, and the Y-axis pulse motor 28a constitute an indexing feed unit.

[0031] Further, a pair of Z-axis guide rails 30 parallel to the Z-axis direction are provided on the surface (front surface) of each Y-axis moving plate 26. A Z-axis moving plate 32 is slidably attached to each Z-axis guide rail 30. A nut portion (not shown) is provided on the back surface (rear surface) of the Z-axis moving plate 32, and a Z-axis ball screw 34 parallel to the Z-axis guide rail 30 is screwed into this nut portion. A Z-axis pulse motor 36 is connected to one end of the Z-axis ball screw 34.

[0032] When the Z-axis ball screw 34 is rotated by the Z-axis pulse motor 36, the Z-axis moving plate 32 moves in the Z-axis direction (the incision feed direction) along the Z-axis guide rail 30. In other words, the Z-axis guide rail 30, the Z-axis moving plate 32, the Z-axis ball screw 34, and the Z-axis pulse motor 36 constitute a incision feed unit.

[0033] A cutting unit (working unit) 18 that processes the workpiece and an imaging unit 38 that can image the workpiece held on the chuck table 8 are fixed to the lower part of each of the two Z-axis moving plates 32. When the Y-axis moving plate 26 is moved in the Y-axis direction, the cutting unit 18 and the imaging unit 38 move in the Y-axis direction (indexing feed direction). When the Z-axis moving plate 32 is moved in the Z-axis direction, the cutting unit 18 and the imaging unit 38 move in the Z-axis direction (cutting feed direction).

[0034] 3 includes a perspective view that shows the cutting unit 18. The cutting unit 18 has a spindle 18c along the Y-axis direction, which is a direction parallel to the holding surface 8a of the chuck table 8, and an annular cutting blade 18a attached to the tip of the spindle 18c. The other end side of the spindle 18c is rotatably accommodated in a spindle housing 18b, and a rotation drive source (not shown) such as a motor that rotates the spindle 18c is accommodated inside the spindle housing 18b.

[0035] The cutting blade 18a has, for example, a disk-shaped base. A substantially circular mounting hole penetrating the base is provided in the center of the base, and when the cutting blade 18a is mounted on the cutting unit 18, the tip of the spindle 18c passes through the mounting hole. An annular cutting edge is fixed to the outer periphery of the base for cutting into the workpiece held on the chuck table 8. The cutting edge is also called a grindstone portion. The cutting edge has abrasive grains such as diamond and a binder that disperses and fixes the abrasive grains. The binder is formed of, for example, metal or resin.

[0036] Returning to Fig. 1, the description of the cutting device 2 will be continued. When cutting the workpiece, the imaging unit 38 detects devices, patterns, etc. formed on the surface of the workpiece in advance, and thereby the position of the planned dividing line set on the surface of the workpiece is recognized. Then, the chuck table 8 is rotated so that the extension direction of the planned dividing line matches the processing feed direction of the cutting device 2. Then, the processing feed unit and the indexing feed unit are operated to position the cutting blade 18a above the extension line of the planned dividing line of the workpiece.

[0037] The cutting blade 18a is rotated by rotating the spindle 18c, and the height of the cutting unit 18 is adjusted so that the lower end of the cutting edge of the cutting blade 18a is at a height position lower than the back surface (lower surface) of the workpiece. The cutting feed unit including the Z-axis pulse motor 36 positions the cutting unit 18 at a predetermined height position.

[0038] The machining feed unit is operated to move the chuck table 8 in the machining feed direction for machining feed, and the cutting blade 18a cuts into the workpiece to cut the workpiece. After the workpiece has been cut along one planned dividing line, the indexing feed unit is operated to index and feed the cutting unit 18, and then the chuck table 8 is again machine-fed to cut the workpiece along the other planned dividing line. In this manner, the cutting device 2 cuts the workpieces one after another.

[0039] The cutting device 2 further includes a control unit 42. The control unit 42 has a function of controlling each component of the cutting device 2, such as the cutting unit 18, the chuck table 8, each moving mechanism, the imaging unit 38, and a white light interferometer 40 (described later). The function of the control unit 42 is realized, for example, as software of an apparatus control computer.

[0040] That is, the control unit 42 is configured by a computer including a processing device such as a CPU and a storage device such as a flash memory. By operating the processing device according to software such as a program stored in the storage device, the control unit 42 functions as a concrete means in which the software and the processing device (hardware resource) work together.

[0041] As described above, the cutting device (device) 2 includes multiple linear motion mechanisms such as a processing feed unit, an indexing feed unit, and a cutting feed unit. These linear motion mechanisms respectively linearly move the chuck table (support table) 8 and the cutting unit (working unit) 18 relative to each other along a specific feed direction. In the cutting device 2, these linear motion mechanisms operate with high precision, allowing the workpiece to be machined with high precision.

[0042] Conversely, if these linear motion mechanisms do not operate properly, the cutting device 2 cannot perform the specified cutting process on the workpiece. For this reason, it is desirable to measure the operational accuracy of each linear motion mechanism. Here, evaluation items for the operational accuracy of the linear motion mechanisms will be explained using the operation of the processing feed unit as an example. The processing feed unit has the function of linearly moving the chuck table (support table) 8 in the X-axis direction (feed direction).

[0043] If there is a problem with the operational accuracy of the processing feed unit, the chuck table 8 may rotate about the Z-axis direction (perpendicular to the feed direction). This phenomenon is called yawing. The chuck table 8 may also rotate about the Y-axis direction (perpendicular to the feed direction). This phenomenon is called pitching. The chuck table 8 may also rotate about the X-axis direction (feed direction). This phenomenon is called rolling.

[0044] When measuring the operation accuracy of the linear motion mechanism, for example, a measuring jig described in JP 2017-199777 A is used. With this measuring jig, the operation accuracy of the linear motion mechanism can be measured at the processing point when the cutting blade 18a contacts the workpiece. This measuring jig is attached to the cutting unit 18 for use.

[0045] However, when using this measuring jig, the mounting position of the measuring jig on the cutting unit 18 must be changed every time the measurement item such as pitching and yawing is changed. This work of changing the mounting position is performed by the operator, which is a factor that takes time to measure the operational accuracy of the linear movement mechanism. Also, even if this measuring jig is used, rolling cannot be measured.

[0046] Therefore, the measuring jig according to this embodiment is used to measure the operation accuracy of the linear motion mechanism. Fig. 2 is a perspective view that shows a model of the measuring jig 1 according to this embodiment. Next, the measuring jig 1 will be described. The measuring jig 1 is used together with a white light interferometer, which will be described later, in a state where it is brought into contact with the linear motion mechanism, the operation accuracy of which is to be measured, via a chuck table 8 (table base 8b) or the like.

[0047] The measuring jig 1 is formed of a hard metal material such as stainless steel. The measuring jig 1 has a planar bottom surface 3, a parallel surface 5 that faces the bottom surface 3 and is parallel to the bottom surface 3, and an inclined surface 9 that is connected to the parallel surface 5 via a linear boundary line 7 and is inclined with respect to the parallel surface 5. In each drawing, the gradient of the inclined surface 9 of the measuring jig 1 is greatly exaggerated for ease of explanation.

[0048] The gradient of the inclined surface 9 with respect to the parallel surface 5 is preferably 1 / 15000 or more and 1 / 5000 or less. The gradient is more preferably 1 / 12500 or more and 1 / 7500 or less, and particularly preferably 1 / 11000 or more and 1 / 9000 or less. And, the gradient is most preferably 1 / 10000.

[0049] The length of the measuring jig 1 along the boundary line 7 is preferably greater than, for example, the length of an area that can become a processing point on the chuck table (support table) 8. In other words, it is preferably greater than the diameter of the holding surface (support surface) 8a. For example, when the diameter of the holding surface 8a is 300 mm, the length of the measuring jig 1 is preferably about 350 mm.

[0050] Moreover, the height of the measuring jig 1 is preferably equal to that of the chuck table 8, for example, about 20 mm. As described later, the measuring jig 1 may be used by being placed on a table base 8b that supports the chuck table 8. If the measuring jig 1 has a thickness equal to that of the chuck table 8, the upper surface of the measuring jig 1 placed on the table base 8b will be equal to the height position of the processing point. The width perpendicular to the height and length of the measuring jig 1 is preferably about 80 mm. The boundary line 7 is preferably provided near the center in the width direction. However, the dimensions of each part of the measuring jig 1 are not limited to these, and may be appropriately determined within a range in which the parallel surface 5 and the inclined surface 9 can be simultaneously accommodated in a sufficiently wide observation area 40a by the white light interferometer 40 described later.

[0051] What is particularly important for the measuring jig 1 to function is that the bottom surface 3, the parallel surface 5, and the inclined surface 9 each have high flatness, that the bottom surface 3 and the parallel surface 5 are parallel with high accuracy, and that the gradient of the inclined surface 9 with respect to the parallel surface 5 is within the above-mentioned range. However, there are cases where the measuring jig 1 can function even when the parallel surface 5 is not parallel with the bottom surface 3 with high accuracy. Therefore, as long as the gradient of the parallel surface 5 with respect to the bottom surface 3 is smaller than the gradient of the inclined surface 9 with respect to the parallel surface 5, the bottom surface 3 and the parallel surface 5 do not need to be parallel with high accuracy, and there are cases where the bottom surface 3 and the parallel surface 5 do not need to be parallel. The function and usage of the measuring jig 1 will be described in detail later.

[0052] Next, a white light interferometer used together with the measuring jig 1 will be described. The white light interferometer is used, for example, connected to a cutting unit (work unit) 18. Fig. 3 shows a schematic diagram of a white light interferometer 40 connected to the cutting unit 18. The white light interferometer 40 has a function of observing the measuring jig 1 placed on the chuck table 8.

[0053] The white interferometer 40 is connected to the cutting unit 18 via, for example, a ball screw type lifting mechanism (not shown), and is movable along the Z-axis direction (direction perpendicular to the feed direction). However, the lifting mechanism is not limited to being of the ball screw type. The white interferometer 40 may be permanently fixed to the cutting unit (work unit) 18, or may be detached as necessary. The lifting mechanism allows adjustment of the distance of the white interferometer 40 to the measurement jig 1, and the length of the optical path to be adjusted.

[0054] Next, the configuration of the white interferometer 40 will be described. Fig. 4 is a side view showing a schematic example of the simplest configuration of the optical system of the white interferometer 40. The optical system of the white interferometer 40 can be appropriately changed in configuration so that the white interferometer 40 can perform a predetermined function. The white interferometer 40 shown in Fig. 4 is composed of a white light source 44, a first lens 46, a beam splitter 48, an interference objective lens 50, a second lens 52, and an array sensor 54.

[0055] The white light source 44 may be, for example, a white LED (Light Emitting Diode) or a halogen lamp. The white light source 44 has a function of emitting white light having a wide intensity in the visible light region. The white light 56 ​​emitted from the white light source 44 reaches the first lens 46. The first lens 46 has a function of converting the white light 56 ​​into parallel light. The white light 56 ​​converted into parallel light by the first lens 46 is reflected by the beam splitter 48 and proceeds to the interference objective lens 50.

[0056] The interference objective lens 50 has a function of splitting the white light 56 ​​into two, reflecting one of the light beams back, and irradiating the other light beam onto the measurement tool 1. The interference objective lens 50 includes, for example, a reference mirror 50a therein that reflects back a portion of the white light 56. However, the interference objective lens 50 is not limited to this.

[0057] The other of the white lights 56 irradiated to the measurement jig 1 is reflected by the measurement jig 1 and proceeds to the interference objective lens 50, and is returned to the same optical path as the one of the white lights 56. The combined white light 56 ​​passes through the beam splitter 48 and is focused on the array sensor 54 by the second lens 52. The array sensor 54 includes a light receiving element such as a CMOS sensor or a CCD sensor, and captures an image of the white light 56.

[0058] When the white light 56 ​​is imaged by the array sensor 54, an interference fringe (spatial interference pattern) is obtained that reflects the optical path difference between the two components of the split and integrated white light 56. That is, the pattern becomes brighter where the phases of the two components of the white light 56 ​​are in phase, and the pattern becomes darker where the phases of the two components are shifted by a half wavelength. Therefore, information regarding the height distribution of the upper surface of the measuring jig 1 can be obtained from the interference fringes obtained by the array sensor 54.

[0059] The white light 56 ​​is low-coherence light having intensity in a broad wavelength range, and has a very short coherence length. Therefore, the interference fringes observed by the array sensor 54 do not include elements other than the top surface of the measuring jig 1 positioned near the focal height, and high vertical resolution can be obtained with low noise.

[0060] 5(A) is a photograph 56a created assuming interference fringes (spatial interference pattern) obtained by observing the vicinity of boundary line 7 of measuring jig 1 with white light interferometer 40. Note that this photograph 56a is not an observation image obtained by actually observing measuring jig 1 with white light interferometer 40, but an observation image created for the following explanation. Therefore, photograph 56a cannot be used for purposes other than the explanation, and photograph 56a has no other meaning.

[0061] In the left half of the photograph 56a, the brightness is generally uniform, and in the right half of the photograph 56a, multiple stripes are observed at regular intervals along the vertical direction. This means that in the left half of the observation area of ​​the white light interferometer 40, the top surface of the measuring jig 1 is at a uniform height relative to the white light interferometer 40, and in the right half of the observation area, the top surface of the measuring jig 1 is inclined at a constant gradient. In other words, this means that the left half of the observation area is the parallel surface 5, the right half is the inclined surface 9, and the boundary line 7 is between them.

[0062] Here, the spacing and number of multiple fringes generated by the inclined surface 9 are determined by the magnitude of the gradient of the inclined surface 9. If the gradient of the inclined surface 9 is too small, the number of fringes appearing in the observed image will be reduced, making it difficult to detect changes in the interference fringes as described below. On the other hand, if the gradient of the inclined surface 9 is too large, the spacing between the fringes will be too small, making it difficult to distinguish two adjacent fringes. Therefore, it is preferable that the gradient of the inclined surface 9 be of the magnitude described above.

[0063] The measuring jig 1 is placed on a chuck table (support table) 8, or on a table base 8b capable of supporting the chuck table 8. Then, the processing feed unit (linear movement mechanism) is operated while observing the upper surface of the measuring jig 1 with a white light interferometer 40. At this time, the operational accuracy of the processing feed unit can be calculated from the change in the obtained interference fringes. Next, a method for measuring the operational accuracy of a linear movement mechanism using the measuring jig 1 and the white light interferometer 40 will be described. FIG. 6 is a flowchart showing the flow of each step of the operational accuracy measuring method.

[0064] In the method for measuring the operational accuracy of a linear movement mechanism, first, a placing step S10 is performed in which the measuring jig 1 is placed on a chuck table (support table) 8 or a table base 8b capable of supporting the chuck table 8. More specifically, in the placing step S10, the bottom surface 3 of the measuring jig 1 is directed toward the holding surface 8a of the chuck table 8, and the bottom surface 3 is brought into contact with the chuck table 8, exposing the upper surface (parallel surface 5 and inclined surface 9) of the measuring jig 1 upward.

[0065] Alternatively, in the placing step S10, the bottom surface 3 of the measuring jig 1 is directed toward the upper surface of the table base 8b from which the chuck table 8 has been removed, and the bottom surface 3 is brought into contact with the table base 8b, exposing the upper surface of the measuring jig 1 upward. Below, an example will be described in which the measuring jig 1 is placed on the table base 8b from which the chuck table 8 has been removed.

[0066] Next, an adjustment step S20 is performed to adjust the orientation and position of the measuring jig 1 and the position of the white light interferometer 40. FIG. 3 includes a perspective view that shows a schematic of the measuring jig 1 whose orientation and position have been adjusted on the table base 8b. In the adjustment step S20, the orientation of the measuring jig 1 is adjusted so that the boundary line 7 of the measuring jig 1 is parallel to the feed direction (processing feed direction, X-axis direction). In other words, the movement direction of the element that moves linearly by operating the linear movement mechanism whose operational accuracy is to be measured is aligned with the extension direction of the boundary line 7 of the measuring jig 1.

[0067] Then, in adjustment step S20, the positions of the measuring jig 1 and the white interferometer 40 are adjusted so that the parallel surface 5 and the inclined surface 9 of the measuring jig 1 can be simultaneously observed by the white interferometer 40 connected to the cutting unit (work unit) 18. In particular, it is preferable that the observation area 40a of the white interferometer 40 is positioned near one end of the boundary line 7, as shown in FIG.

[0068] For example, the operator adjusts the position of the measuring jig 1 on the table base 8b while maintaining the orientation of the measuring jig 1 so that the boundary line 7 falls within the observation area 40a of the white light interferometer 40. Alternatively, the operator operates the processing feed unit and the indexing feed unit while observing the upper surface of the measuring jig 1 with the white light interferometer 40 to adjust the positions of the cutting unit 18 and the measuring jig 1 so that the boundary line 7 falls within the observation area 40a.

[0069] After performing the adjustment step S20, it is advisable to observe the upper surface of the measurement jig 1 with the white interferometer 40 while adjusting the height of the white interferometer 40. At this time, if interference fringes such as those shown in the photograph 56a in Fig. 5(A) are confirmed, it is confirmed that the white interferometer 40 is oriented in the appropriate direction. In other words, if no interference fringes appear in the area corresponding to the parallel surface 5 of the observation image and the brightness is roughly uniform, and multiple fringes parallel to the boundary line 7 appear in the area corresponding to the inclined surface 9 of the observation image, it is confirmed that there is no problem with the orientation of the white interferometer 40.

[0070] On the other hand, when the white interferometer 40 is operated to observe the upper surface of the measurement jig 1, if an observation image of interference fringes such as that shown in the photograph 56a is not obtained, it is necessary to check the connection state of the white interferometer 40 to the cutting unit 18 and adjust the orientation of the white interferometer 40. For example, the white interferometer 40 may be connected to the cutting unit 18 via a two-axis goniostage for adjusting the orientation, and the orientation of the white interferometer 40 may be adjusted by this goniostage.

[0071] After it is confirmed that the orientation of the white interferometer 40 is appropriate, an interference fringe observation step S30 is performed to observe changes in the interference fringes observed by the white interferometer 40. In the interference fringe observation step S30, the cutting unit (work unit) 18 and the measuring jig 1 are linearly moved relatively in the X-axis direction (feed direction) by the processing feed unit (linear movement mechanism), while the parallel surface 5 and the inclined surface 9 are observed by the white interferometer 40 along the boundary line 7. The changes in the interference fringes at this time are observed.

[0072] Here, the processing feed unit may be temporarily stopped every time the upper surface of the measuring jig 1 is observed by the white interferometer 40. In this case, interference fringes can be precisely observed at various locations on the upper surface of the measuring jig 1. Alternatively, while the interference fringe observation step S30 is being performed, the processing feed unit may not be stopped, and the white interferometer 40 may be periodically operated to observe the upper surface of the measuring jig 1. In this case, the time required to observe the interference fringes can be shortened.

[0073] The white light interferometer 40 is connected to, for example, a control unit 42 of the cutting device (machine) 2, and transmits an observation image showing interference fringes obtained by observation to the control unit 42. The control unit 42 evaluates the interference fringes shown in the observation image transmitted from the white light interferometer 40, accumulates the evaluation results, and creates information regarding changes in the interference fringes.

[0074] Following the interference fringe observation step S30, an operation accuracy determination step S40 is carried out to determine the operation accuracy of the processing feed unit (linear movement mechanism) from the change in the observed interference fringes. Next, a method for determining the operation accuracy of the processing feed unit will be described. In the operation accuracy determination step S40, for example, the yawing accuracy, pitching accuracy, and rolling accuracy of the operation accuracy of the processing feed unit (linear movement mechanism) are determined.

[0075] If the yawing accuracy of the processing feed unit is low, the table base 8b rotates about the Z-axis direction (direction perpendicular to the feed direction) while the cutting unit 18 and the table base 8b are moved relatively in the X-axis direction (feed direction). Therefore, in the interference fringe observation step S30, a change occurs in the observation image obtained by observing the upper surface of the measuring jig 1 with the white light interferometer 40.

[0076] 5(B) is a photograph 56b created assuming interference fringes (spatial interference pattern) obtained by observing the vicinity of boundary line 7 of measuring jig 1 with white light interferometer 40 when yawing occurs. Note that, like photograph 56a, photograph 56b is not an observation image obtained by actually observing measuring jig 1 with white light interferometer 40, but an observation image created for the following explanation.

[0077] When yawing occurs, an overall tilt occurs in the observation image showing the interference fringes. More specifically, the boundary line 7 of the measuring jig 1 and the interference fringes appearing in the area of ​​the inclined surface 9 are tilted at the same angle from the X-axis direction (feed direction). The magnitude of this tilt angle corresponds to low yawing accuracy. Therefore, while the cutting unit (work unit) 18 and the measuring jig 1 move linearly relative to each other, observation is performed from one end to the other of the boundary line 7 of the measuring jig 1 using a white light interferometer 40, and the tilt angle of the interference fringes of the inclined surface 9, etc. is measured from each of the obtained observation images.

[0078] Then, the yawing tendency can be evaluated from the tendency of change in the tilt angle, and the yawing accuracy, which is part of the operational accuracy of the processing feed unit (linear movement mechanism), can be calculated based on the maximum change in the tilt angle. For example, in a series of obtained observation images, if the change in the tilt angle of the interference fringes of the inclined surface 9 etc. is sufficiently small and the boundary line 7 etc. is always along the X-axis direction (feed direction), it can be said that the yawing accuracy is good.

[0079] Furthermore, if the pitching accuracy of the processing feed unit is low, the table base 8b rotates about the Y-axis direction (direction perpendicular to the feed direction) while the cutting unit 18 and the table base 8b are moved relatively in the X-axis direction (feed direction). At this time, a change occurs in the observation image obtained by observing the upper surface of the measuring jig 1 with the white light interferometer 40.

[0080] 5(C) is a photograph 56c created assuming interference fringes obtained by observing the vicinity of boundary line 7 of measuring jig 1 with white interferometer 40 when pitching occurs. Note that, like photograph 56a, photograph 56c is not an observation image obtained by actually observing measuring jig 1 with white interferometer 40, but an observation image created for the following explanation.

[0081] When pitching occurs, the distance between the upper surface of the measuring jig 1 and the white interferometer 40 changes, causing phenomena such as focus shift in the observation image showing the interference fringes, changes in the brightness of the interference fringes, and parallel movement of each fringe along the Y-axis direction. The amount of focus shift in the observation image, the amount of change in the brightness of the interference fringes, and the amount of movement of each fringe correspond to low pitching accuracy. Therefore, the change in the brightness of the interference fringes observed while the cutting unit 18 and the measuring jig 1 move relative to each other is measured.

[0082] Then, the tendency of pitching can be evaluated from the tendency of the brightness change, and the pitching accuracy, which is part of the operational accuracy of the processing feed unit (linear movement mechanism), can be calculated based on the maximum amount of change in brightness. For example, if the change in brightness of the interference fringes in the series of obtained observation images is sufficiently small and the brightness of the interference fringes is constant, it can be said that the pitching accuracy is good.

[0083] Furthermore, when the tendency of pitching is evaluated from the defocus of the observation image, for example, when the defocus of the observation image is confirmed, the operation of the processing feed unit is stopped and the white interferometer 40 is raised and lowered. At this time, the amount of pitching can be evaluated from the amount of elevation of the white interferometer 40 until the observation image is brought back into focus. Then, the movement of the chuck table 8 and the like and the elevation and lowering of the white interferometer 40 are repeated to evaluate the tendency of pitching, and the difference between the height when the white interferometer 40 is at its highest and its lowest can be calculated as the pitching accuracy.

[0084] Furthermore, if the rolling accuracy of the processing feed unit (linear movement mechanism) is low, the table base 8b rotates about the X-axis direction (feed direction) as an axis while the cutting unit 18 and the table base 8b are moved relatively in the X-axis direction (feed direction). At this time, a change occurs in the observation image obtained by observing the upper surface of the measuring jig 1 with the white light interferometer 40.

[0085] 5(D) is a photograph 56d created assuming interference fringes obtained by observing the vicinity of boundary line 7 of measuring jig 1 with white interferometer 40 when rolling is occurring. Note that, like photograph 56a, photograph 56d is not an observation image obtained by actually observing measuring jig 1 with white interferometer 40, but an observation image created for the following explanation.

[0086] When rolling occurs, the parallel surface 5 of the measuring jig 1 tilts, and the height of each point on the parallel surface 5 is no longer uniform, so that interference fringes become visible on the parallel surface 5. In addition, the height of each point on the inclined surface 9 also changes, so the spacing of the interference fringes generated on the inclined surface 9 changes depending on the magnitude of rolling. Therefore, by observing the presence or absence of interference fringes on the parallel surface 5 or the change in the spacing of the interference fringes on the inclined surface 9 observed while the cutting unit 18 and the measuring jig 1 move relative to each other, the tendency of rolling can be evaluated.

[0087] For example, the rolling accuracy of the operation accuracy of the processing feed unit (linear movement mechanism) can be calculated based on the maximum change in the fringe spacing. Also, if the change in the fringe spacing is sufficiently small in the series of observation images obtained that fringes do not appear on the parallel surface 5, it can be said that the rolling accuracy is good.

[0088] If the operation accuracy of the processing feed unit (linear movement mechanism) is found to not meet a predetermined level after determining the operation accuracy using the measuring jig 1, the processing feed unit should be maintained or replaced. After that, the operation accuracy of the processing feed unit (linear movement mechanism) should be similarly determined. If it is found that the operation accuracy meets the predetermined level, it is confirmed that one of the conditions for properly processing the workpiece with the cutting device 2 has been achieved.

[0089] The operation accuracy of each linear movement mechanism in the cutting device 2 may be determined, for example, when the cutting device 2 is installed in a factory or the like. Alternatively, it may be determined after a predetermined period of time has elapsed since the cutting device 2 has been in operation. This allows the cutting device 2 to be maintained in a state in which it can process the workpiece with high accuracy. Furthermore, with the measuring jig 1 according to this embodiment, the operation accuracy can be determined quickly, so that the cutting device 2 can be operated for a long time.

[0090] As described above, the measuring jig 1 has the parallel surface 5 parallel to the bottom surface 3 and the inclined surface 9 slightly inclined relative to the parallel surface 5, so that the operating accuracy of the linear motion mechanism can be calculated with high precision by using it in combination with the white light interferometer 40. At this time, there is no need to reset the measuring jig 1 for each item of operating accuracy. In other words, by operating the linear motion mechanism once, the operating accuracy can be calculated multilaterally and with high precision in an extremely short time.

[0091] In the above description, the linear motion mechanism is the machining feed unit of the cutting device 2, and the operational accuracy of the machining feed unit is calculated using the measurement jig 1 and the white light interferometer 40. However, the linear motion mechanism whose operational accuracy is to be measured is not limited to this. In other words, the operational accuracy of the indexing feed unit may be calculated by a similar method using the measurement jig 1 and the white light interferometer 40.

[0092] Furthermore, the operating accuracy of the cutting feed unit of the cutting device 2 may be calculated using the measuring jig 1 and the white light interferometer 40. The cutting feed unit is a linear movement mechanism that raises and lowers the cutting unit 18 relative to the chuck table 8.

[0093] Therefore, for example, the measuring jig 1 is fixed upright on the holding surface 8a of the chuck table 8 or the upper surface of the table base 8b. At this time, the upper surface of the measuring jig 1 is faced toward the cutting unit 18 in the Y-axis direction. Then, the white interferometer 40 is fixed to the cutting unit 18 facing the measuring jig 1. Thereafter, the cutting unit is operated to raise and lower the cutting unit 18 while observing the parallel surface 5 and the inclined surface 9 of the measuring jig 1 along the boundary line 7 with the white interferometer 40. Then, the operating accuracy of the cutting feed unit can be calculated based on the change in the obtained interference fringes.

[0094] In the above description, the measurement jig 1 is placed on the table base 8b (chuck table 8) and the white interferometer 40 is connected to the cutting unit 18, but the measurement jig 1 and the white interferometer 40 may be used interchangeably. That is, the measurement jig 1 may be fixed to the cutting unit 18, the white interferometer 40 may be placed on the table base 8b (chuck table 8), and the upper surface of the measurement jig 1 may be observed by the white interferometer 40. What is important is that the measurement jig 1 is brought into contact with one of the elements that are moved by the linear movement mechanism and the elements that are not moved, and the white interferometer 40 is brought into contact with the other.

[0095] Furthermore, in the above description, the measurement jig 1 and the white interferometer 40 are used to determine the operating accuracy of a linear movement mechanism such as a processing feed unit in the cutting device 2 having the cutting unit 18, but the use of the measurement jig 1 and the white interferometer 40 is not limited to this. For example, in an inspection device that scans a microscope to inspect a sample supported on a moving table, the measurement jig 1 and the white interferometer 40 may be used to determine the operating accuracy of a linear movement mechanism that moves the moving table and the microscope relatively in a straight line.

[0096] By using the measuring jig 1 and the white interferometer 40, the operation accuracy of a linear motion mechanism that moves a support table and a working unit relatively linearly can be calculated in any device incorporating the linear motion mechanism. The measuring jig 1 and the white interferometer 40 do not need to be used exclusively for a specific device, and may be used widely as an operation accuracy measurement system for linear motion mechanisms. In other words, the measuring jig 1 according to this embodiment may constitute an operation accuracy measurement system together with the white interferometer 40.

[0097] This operation accuracy measurement system measures the operation accuracy of a linear movement mechanism in an apparatus equipped with a support table having a support surface and supporting an object, an operation unit that performs either a machining or measurement operation on the object supported by the support table, and a linear movement mechanism that moves the operation unit and the support table relatively linearly along a feed direction. The operation accuracy measurement system includes a white light interferometer 40 and a measurement jig 1.

[0098] The white light interferometer 40 can observe a working point on the support table where the working unit performs an operation on an object, and is connected to the working unit so as to be movable in a direction perpendicular to the feed direction. The measuring jig 1 has a flat bottom surface 3, a parallel surface 5 that faces the bottom surface 3 and is parallel to the bottom surface 3, and an inclined surface 9 that is connected to the parallel surface 5 via a linear boundary line 7 and is inclined with respect to the parallel surface 5.

[0099] Then, the measuring jig 1 is placed on the support surface with boundary line 7 oriented in a direction parallel to the feed direction and positioned at a position where parallel surface 5 and inclined surface 9 can be simultaneously observed within the observation range of white light interferometer 40. Next, the linear movement mechanism is operated to relatively move the working unit and the support table linearly in the feed direction while observing changes in the interference fringes of parallel surface 5 and inclined surface 9 of measuring jig 1 with white light interferometer 40. Then, the operating accuracy of the linear movement mechanism is calculated based on the changes in the interference fringes.

[0100] In the above embodiment, the case where the white interferometer 40 irradiates the measurement jig 1 with white light having an intensity in a wide wavelength range to observe the interference fringes has been described, but the light that the white interferometer 40 irradiates the measurement jig 1 with is not limited to white light. For example, the heights of each point of the parallel surface 5 and the inclined surface 9, i.e., the inclination of each surface, may be detected by a phase cross method using monochromatic light.

[0101] Although the case where the white light interferometer 40 is used to observe the interference fringes has been described, one embodiment of the present invention is not limited to this. That is, the interference fringes may be observed using a laser interferometer instead of the white light interferometer 40.

[0102] Furthermore, in the above embodiment, when the measuring jig 1 is placed on the table base 8b and the upper surface of the measuring jig 1 is observed with the white interferometer 40, if interference fringes appear not only on the inclined surface 9 but also on the parallel surface 5, the orientation of the white interferometer 40 is adjusted. However, even in this case, the orientation of the white interferometer 40 does not necessarily need to be adjusted.

[0103] An important factor in determining the operational accuracy of the linear motion mechanism is the change in the interference fringes observed by the white light interferometer 40 when the linear motion mechanism is operated. In other words, even if the orientation of the white light interferometer 40 is not adjusted initially, the operational accuracy of the linear motion mechanism can be determined appropriately as long as the change in the interference fringes when the linear motion mechanism is operated can be properly detected. For example, if there is no change in the interference fringes observed on the parallel surface 5 while the linear motion mechanism is operated, it can be understood that the operational accuracy of the linear motion mechanism is high.

[0104] In the above embodiment, the bottom surface 3 and the parallel surface 5 of the measuring jig 1 are parallel with high accuracy. However, the parallel surface 5 may be inclined with respect to the bottom surface 3. Even in this case, when the upper surface of the measuring jig 1 is observed with the white light interferometer 40, the parallel surface 5 does not have a uniform brightness, and interference fringes appear not only on the inclined surface 9 but also on the parallel surface 5. However, the operating accuracy of the linear movement mechanism can be calculated based on the change in the interference fringes of the parallel surface 5 while the linear movement mechanism is operated. Therefore, the parallel surface 5 does not need to be parallel with the bottom surface 3 with high accuracy.

[0105] Furthermore, in the above embodiment, the measuring jig 1 is used by being placed on the table base 8b from which the chuck table 8 has been removed, but the measuring jig 1 may be used by being placed on the chuck table 8. For example, in an apparatus that does not include the table base 8b and in which the chuck table 8 is directly connected to a linear movement mechanism, it may not be easy to remove the chuck table 8. In this case, the measuring jig 1 is used by being placed on the holding surface 8a of the chuck table 8.

[0106] Furthermore, even in an apparatus having a table base 8b, the measuring jig 1 may be used by being placed on the holding surface 8a of the chuck table 8. In this case, the measuring jig 1 can be used without removing the chuck table 8 from the table base 8b, and after determining the operating accuracy of the linear motion mechanism, the apparatus can be used immediately by simply moving the measuring jig 1 from the chuck table 8. This increases the efficiency of measuring the operating accuracy of the linear motion mechanism, and also increases the operating efficiency of the apparatus.

[0107] However, although the chuck table (support table) 8 is basically manufactured so that the bottom surface and the holding surface 8a are parallel, there is a certain degree of variation in the accuracy of the inclination of the bottom surface and the holding surface 8a and in the thickness distribution of the chuck table 8. Therefore, when the measuring jig 1 is placed on the holding surface 8a of the chuck table 8, the upper surface of the measuring jig 1 may be inclined due to the shape of the chuck table 8. Therefore, when the measuring jig 1 is used by placing it on the table base 8b as in the above embodiment, the operating accuracy of the linear movement mechanism can be calculated without being affected by the shape of the chuck table 8.

[0108] In addition, the structures, methods, etc. according to the above-described embodiments can be modified as appropriate without departing from the scope of the object of the present invention. [Explanation of symbols]

[0109] 1 Measuring tool 3 Bottom 5 Parallel Planes 7. Boundaries 9 Slope 2 Cutting equipment (equipment) 4 Equipment base 6 X-axis moving table 8 Chuck table 8a Holding surface 8b Table Base 10 Clamp 12 X-axis guide rail 14 X-axis ball screw 16 X-axis pulse motor 18 Cutting unit (working unit) 18a cutting blade 18b Spindle housing 18c spindle 20 Drainage Channel 22 Support structure 24 Y-axis guide rail 26 Y-axis moving plate 28 Y-axis ball screw 28a Y-axis pulse motor 30 Z-axis guide rail 32 Z-axis moving plate 34 Z-axis ball screw 36 Z-axis pulse motor 38 Imaging unit 40 White light interferometer 40a Observation area 42 Control Unit 44 White light source 46 First lens 48 Beam splitter 50 Interference Objective Lens 50a Reference Mirror 52 Second lens 54 Array Sensor 56 white light 56a, 56b, 56c, 56d Photos

Claims

1. A flat bottom surface; a parallel surface facing the bottom surface and parallel to the bottom surface; an inclined surface connected to the parallel surface via a linear boundary line and inclined with respect to the parallel surface; It is made of metal material, a gradient of the inclined surface with respect to the parallel surface is equal to or greater than 1 / 15000 and equal to or less than 1 / 5000; The measurement jig is characterized in that the bottom surface, the parallel surface and the inclined surface are each sufficiently flat that interference fringes based on light reflected by the parallel surface and the inclined surface can be observed by an interferometer.

2. An operation accuracy measurement system for measuring operation accuracy of a linear movement mechanism in an apparatus including a support table having a support surface and supporting an object, an operation unit that performs either a machining or measuring operation on the object supported by the support table, and a linear movement mechanism that relatively moves the operation unit and the support table linearly along a feed direction, comprising: a white light interferometer connected to the operational unit so as to be movable in a direction perpendicular to the feed direction, the white light interferometer being capable of observing a working point on the support table where the operational unit performs an operation on an object; a measuring tool having a planar bottom surface, a parallel surface facing the bottom surface and parallel to the bottom surface, and an inclined surface connected to the parallel surface via a linear boundary line and inclined with respect to the parallel surface; the boundary line is oriented in a direction parallel to the feed direction and is positioned in a position within the observation range of the white light interferometer where the parallel surface and the inclined surface can be simultaneously observed, and the measurement jig is placed on the support table or on a table base that can support the support table, and the linear motion mechanism is operated to move the work unit and the measurement jig relatively linearly in the feed direction while observing changes in interference fringes on the parallel surface and the inclined surface of the measurement jig with the white light interferometer, and the operational accuracy of the linear motion mechanism is determined based on the changes in the interference fringes by either determining yawing accuracy based on the maximum change in tilt of the interference fringes, determining pitching accuracy based on the maximum change in brightness of the interference fringes, or determining rolling accuracy by observing the presence or absence of interference fringes on the parallel surfaces or changes in the fringe spacing of the interference fringes on the inclined surface.

3. A method for measuring operational accuracy of a linear movement mechanism in an apparatus including a support table having a support surface and supporting an object, a work unit that performs either a machining or measuring operation on the object supported by the support table, and a linear movement mechanism that relatively moves the work unit and the support table linearly along a feed direction, comprising: a placing step of placing a measuring tool having a planar bottom surface, a parallel surface facing the bottom surface and parallel to the bottom surface, and an inclined surface connected to the parallel surface via a linear boundary line and inclined with respect to the parallel surface, on the support table or on a table base capable of supporting the support table; an adjustment step of adjusting the orientation of the measuring jig so that the boundary line of the measuring jig is parallel to the feed direction, and adjusting the positions of the measuring jig and the white light interferometer so that the parallel surface and the inclined surface can be simultaneously observed by the white light interferometer connected to the operation unit; an interference fringe observation step of observing the parallel surface and the inclined surface with the white light interferometer while linearly moving the operational unit and the measurement jig relatively in the feed direction by the linear movement mechanism, and observing a change in the interference fringes; an operation accuracy determining step of determining an operation accuracy of the linear motion mechanism from the observed change in the interference fringes; Including, The operational accuracy determination step determines the yawing accuracy of the operational accuracy based on the maximum change in slope of the interference fringes on the inclined surface observed while the work unit and the measuring jig move relative to each other, determines the pitching accuracy of the operational accuracy based on the maximum change in brightness of the interference fringes observed while the work unit and the measuring jig move relative to each other, or determines the rolling accuracy of the operational accuracy based on the presence or absence of interference fringes on the parallel surface observed while the work unit and the measuring jig move relative to each other, or the change in the fringe spacing of the interference fringes on the inclined surface.

4. 4. The method for measuring operational accuracy according to claim 3, wherein a gradient of the inclined surface of the measuring jig with respect to the parallel surface is equal to or greater than 1 / 15000 and equal to or less than 1 / 5000.

5. 3. The operation accuracy measurement system according to claim 2, wherein a gradient of the inclined surface of the measurement jig with respect to the parallel surface is equal to or greater than 1 / 15000 and equal to or less than 1 / 5000.

Images