TWI720254B - Grinding device - Google Patents

Abstract

[Problem] When a complicated optical system configuration is not necessary, a simple configuration can appropriately detect scratches. [Solution] The grinding device is equipped with a scratch detection device that detects scratches formed on the wafer after grinding. The scratch detection equipment includes a line sensor that photographs the radius of the wafer, a light source extending in the same direction as the line sensor, and a judging device that judges the presence or absence of a scratch based on the image taken by the line sensor. The linear sensor photographs the entire surface of the wafer by rotating the wafer around the center as an axis while photographing the radius of the wafer. The judging device performs coordinate conversion of the captured image to edit it into a strip-shaped image, and judges the presence or absence of scratches based on the strip-shaped image.

Description

Grinding device

FIELD OF THE INVENTION The present invention relates to a grinding device.

BACKGROUND OF THE INVENTION When infeed grinding is performed on a wafer with a grinding device, a saw mark is formed as a grinding mark on the ground surface of the wafer. The knife marks are formed radially from the center of the wafer toward the outer periphery. Among the knife marks, there may be so-called scratches in which the abrasive particles that fall off the grinding stone during processing contact the ground surface of the wafer and cause damage. Since this scratch will affect the components formed on the wafer, it is necessary to confirm the presence or absence of scratches at the end of grinding.

Therefore, there has been proposed a grinding device that detects the scratches of the wafer after the grinding process (see, for example, Patent Document 1). In Patent Document 1, a light beam is irradiated to the ground surface of a processed wafer, and the presence or absence of scratches is determined based on the amount of reflected light. Prior Art Documents Patent Documents

Patent Document 1: Japanese Patent Laid-Open No. 2009-95903

SUMMARY OF THE INVENTION Problems to be Solved by the Invention However, the grinding device described in Patent Document 1 requires a complicated optical system configuration in order to detect the scratches of the wafer. As a result, there is a concern that the overall configuration of the device will be complicated.

The present invention was made in view of the above-mentioned problems, and one of its objects is to provide a grinding device that can be suitably constructed with a simple structure without requiring a complicated optical system. To detect scratches. Means to solve the problem

The grinding device of one aspect of the present invention is a grinding device provided with a grinding device, a holding device, and a scratch detection device. The grinding device is provided with a mounting seat for a grinding wheel and has a grinding wheel The center of the grinding wheel is a spindle unit that rotates as a shaft, wherein the grinding wheel is arranged in a ring shape with a grinding stone, and the holding device is equipped with the center of the wafer held by the holding surface of the work chuck as the axis to make the A table rotating equipment that rotates the work chuck table. The holding surface of the work chuck table is an inclined surface whose outer circumference becomes lower with the center as the apex. The grinding equipment is a grinding stone that rotates by a spindle unit. Through the center of the wafer held by the work chuck, the radius area between the center and the outer circumference of the wafer and the ground part of the arc are ground. The scratch detection equipment has the radius length of the radius of the wafer to be photographed. The linear sensor, a light source extending the same length as the linear sensor, and a judging device, the judging device includes: an editing section that sets the radial direction of the captured image captured by the linear sensor to the vertical The axis and the circumferential direction are set as the horizontal axis to edit into a strip image; and the judgment part, in the strip image edited by the editing part, if the width of the regular straight line is greater than the preset width, or If a line other than the regular straight line appears, it is judged to be scratched, and if the width of the regular straight line is below the preset width, it is judged to be no scratched.

According to this configuration, it is possible to obtain a photographed image of the entire surface of the wafer by rotating the work chuck while allowing the linear sensor to photograph the radius of the wafer. During shooting, since the light source illuminates the radius of the wafer, it is possible to judge the presence or absence of scratches from the brightness of the captured image. In particular, by editing the captured image into a strip image, the scratch can be represented by a regular straight line. Therefore, the width of the straight line can be easily compared with the width of the straight line set in advance. Also, lines other than straight lines with regularity can be easily found. As a result, it is easy to judge the presence or absence of scratches. According to this, it is possible to appropriately detect scratches with a simple configuration without requiring a complicated optical system configuration. Invention effect

According to the present invention, it is possible to appropriately detect scratches with a simple configuration without requiring a complicated optical system configuration.

Modes for Carrying Out the Invention Hereinafter, the grinding apparatus of this embodiment will be described with reference to the attached drawings. Fig. 1 is a perspective view of the grinding device of this embodiment. Fig. 2 is a schematic diagram of the time when a wafer is ground (grinding step) on the grinding device of the present embodiment. In addition, the grinding device is not limited to the device configuration dedicated to grinding processing as shown in FIG. 1, and may be incorporated into, for example, a fully automated system that performs a series of processing such as grinding processing, grinding processing, and cleaning processing in a fully automatic manner. Type (Full Auto Type) processing equipment.

As shown in FIGS. 1 and 2, the grinding device 1 is configured to use a grinding wheel 46 to grind the wafer W held on the work chuck 20, wherein the grinding wheel 46 is used to grind a plurality of grinding wheels. The stone 47 is arranged in an annular shape. The wafer W is carried into the grinding apparatus 1 with the protective tape T attached, and is held on the work chuck table 20. Furthermore, the wafer W may be a plate-shaped member that can be a grinding target, and it may be a semiconductor wafer such as silicon, gallium arsenide, or an optical device wafer such as ceramic, glass, sapphire, or the like. As-sliced wafer before pattern formation.

A rectangular opening extending in the X-axis direction is formed on the upper surface of the base 10 of the grinding device 1, and this opening is formed by a movable plate 11 that can move together with the work clamp table 20 and a bellows-shaped waterproof cover 12 cover. Below the waterproof cover 12 is provided a ball screw type advance and retreat device (not shown) for moving the work clamp table 20 in the X-axis direction. The work chuck table 20 is connected to the table rotating device 24, and is configured to be rotatable about the center of the wafer W as an axis by the drive of the table rotating device 24. The work clamp table 20 and the work table rotating device 24 are combined to serve as a holding device.

On the upper surface of the work chuck table 20, a holding surface 21a for sucking and holding the wafer W by a porous material is formed. Specifically, the work chuck 20 is a porous chuck that sucks and holds the wafer W, and is configured by attaching a disk-shaped porous plate 21 to a frame 22 as a body.

The porous plate 21 is made of a porous material such as ceramics, and has fine pores for suction formed throughout the entirety. The frame body 22 has a circular shape with a larger diameter than the perforated plate 21, and a circular recess 23 for accommodating the perforated plate 21 is formed in the center. The inner surface of the circular recess 23 is formed to have the same inner diameter as the outer diameter of the perforated plate 21. In addition, the depth of the circular recess 23 is formed to be approximately the same as the thickness of the perforated plate 21.

A communication path (not shown) connected to a suction source (not shown) is formed on the frame 22. By inserting the porous plate 21 into the circular recess 23, the communication path can be connected to the porous plate 21. Thereby, a holding surface 21a that can suck and hold the wafer W by the negative pressure of the suction source is formed on the upper surface of the porous plate 21. In particular, the holding surface 21a has an inclined surface whose outer periphery is slightly inclined and lowered with the center of rotation of the work chuck table 20 (the center of the holding surface 21a) as a vertex, as shown in FIG. 2. When the wafer W is sucked and held on the holding surface 21a inclined in the form of a cone, it is deformed into a gently inclined conical shape along the shape of the holding surface 21a.

The support 15 on the base 10 is provided with a grinding feed device 30 that can grind the grinding device 40 in a direction (Z-axis direction) that allows it to approach and move away from the work clamp table 20 Cutting feed. The grinding and feeding device 30 has a pair of guide rails 31 arranged on the support 15 parallel to the Z-axis direction, and a motor-driven Z-axis table 32 provided to be slidable on the pair of guide rails 31. On the back side of the Z-axis table 32, a nut part not shown is formed, and a ball screw 33 is screwed into these nut parts. By rotating the ball screw 33 by the drive motor 34 connected to one end of the ball screw 33, the grinding device 40 can be moved along the guide rail 31 in the Z-axis direction.

The grinding device 40 is installed on the front surface of the Z-axis table 32 through the housing 41, and is configured to rotate the grinding wheel 46 around the center by the spindle unit 42. The main shaft unit 42 is a so-called air main shaft, and can rotatably support the main shaft 44 through high-pressure air inside the casing.

A mounting seat 45 is connected to the front end of the main shaft 44, and a grinding wheel 46 in which a grinding stone 47 is annularly arranged is mounted on the mounting seat 45. The grinding grindstone 47 is formed by bonding diamond abrasive grains of a predetermined abrasive grain size with a vitrified bond, for example. In addition, the grinding grindstone 47 is not limited to this, It can also be formed by fixing diamond abrasive grains with the bonding agent, such as a metal bonding agent or a resin bonding agent.

In addition, the grinding device 1 is provided with a control device 90 for integrating various parts of the control device. The control device 90 is composed of a processor, a memory, and the like that execute various processes. The memory is composed of one or more storage media such as ROM (Read Only Memory) and RAM (Random Access Memory) due to application. The control device 90 is used to control, for example, the grinding feed rate and the grinding feed rate of the grinding device 40 (there are others such as the rotation speed of the grinding wheel). In addition, the control device 90 is used to control various operations of the scratch detection device 50 described later.

On the side of the work chuck table 20, a scratch detection device 50 for detecting scratches formed on the wafer W after grinding is provided. The scratch detection device 50 is configured to include a standing portion 51 standing up from the upper surface of the substrate 10 and a scanning portion 52 extending from the standing portion 51 in the Y-axis direction. The scanning unit 52 is composed of a line sensor 53 that photographs the upper surface of the wafer W, and a light source 54 arranged along the line sensor 53 (also refer to FIG. 4).

The line sensor 53 is composed of, for example, an image sensor, and extends with a length equivalent to the radius of the wafer W. The line sensor 53 can photograph an area corresponding to the radius of the wafer W. The light source 54 extends in the same direction and the same length as the line sensor 53 and irradiates the upper surface of the wafer W with light. Specifically, the light source 54 irradiates light on the wafer W to illuminate the shooting range of the line sensor 53. The details will be described later. The scanning unit 52 can photograph the front surface of the wafer W by rotating the work chuck 20 one turn while photographing the radius of the upper surface of the wafer W.

In addition, the scratch detection device 50 is further provided with a judgment device 55 that judges the presence or absence of a scratch based on the photographed image taken by the scanning unit 52. The judgment device 55 is constituted as a part of the control device 90. The determination device 55 has an editing unit 56 that edits the captured image, and a determination unit 57 that determines the presence or absence of scratches based on the edited captured image. The details of the judging device 55 will be described later.

In the grinding device 1 configured in this way, the grinding wheel 46 can be rotated and contacted with the surface of the wafer W while the rotation axis of the grinding wheel 46 and the rotation axis of the work chuck 20 are shifted. The so-called infeed grinding. Here, referring to FIG. 2, the grinding step of the wafer W will be described.

As shown in FIG. 2, the wafer W is placed on the holding surface 21 a of the work chuck table 20. Specifically, the wafer W is placed on the holding surface 21a so that the surface to which the protective tape T is attached becomes the lower side. The wafer W is sucked and held by the negative pressure generated on the holding surface 21a, and conforms to the shape of the holding surface 21a to become a gently inclined conical shape.

The work clamp table 20 is positioned below the grinding equipment 40. At this time, the rotation axis of the work chuck table 20 is positioned eccentrically from the rotation axis of the grinding stone 47. In addition, the work chuck 20 further adjusts the inclination of the rotating shaft by an unshown inclination adjustment mechanism, so that the grinding surface 47a of the grinding stone 47 and the holding surface 21a become parallel.

Then, the work chuck 20 is rotated, and the grinding device 40 is lowered toward the holding surface 21a by the grinding and feeding device 30 when the grinding grindstone 47 is rotated by the spindle unit 42 (grinding feed). The grinding surface 47a of the grinding grindstone 47 contacts the radius part from the center of the wafer W to the outer periphery in an arc shape.

In this manner, the grinding equipment 40 passes the grinding stone 47 through the center of the wafer W, and grinds the ground portion of the arc of the wafer W in the radius region between the center and the outer periphery of the wafer W. The wafer W can be thinned by gradually grinding and feeding in the Z-axis direction while rotating the grinding stone 47 and the wafer W in contact. Once the wafer W is thinned to a desired thickness, the grinding process is finished.

However, when the wafer is subjected to lateral feed grinding with a grinding device, grinding marks (knife marks) including scratches may be formed on the ground surface of the wafer. As an example of the scratch, a circular arc-shaped pattern (grinding trace) formed regularly from the center of the wafer toward the outer periphery can be cited. In addition, there are cases where the abrasive grains that fall off the grinding stone during processing contact the ground surface of the wafer and cause scratches. Since this scratch will affect the components formed on the wafer, the situation where the scratch is formed is not ideal.

For example, it can be considered that the grinding process is performed by supplying a large amount of grinding water to the upper surface of the wafer to remove the fallen abrasive particles from the ground surface of the wafer, and it is difficult to form scratches. However, it is not economical to increase the supply of grinding water. In addition, a large amount of grinding water becomes the main cause, which leads to the weakening of the force of the grinding stone to the wafer, that is, the engagement of the abrasive grains. As a result, the grinding efficiency may deteriorate. In this way, although the generation of scratches can be suppressed by increasing the grinding water, it is difficult to balance the grinding efficiency. Therefore, it is necessary to confirm the presence or absence of scratches at the end of grinding.

For example, there has been a proposal of a grinding device that irradiates a light beam on the ground surface of a processed wafer, and judges the presence or absence of scratches based on the amount of reflected light. However, in this grinding device, in order to detect the scratches of the wafer, a complicated optical system configuration is required, and as a result, there is a concern that the overall configuration of the device will be complicated.

Therefore, the inventor of the present invention conceived that it is possible to appropriately detect scratches with a simple configuration without requiring a complicated optical system configuration. Specifically, in the present embodiment, the work chuck table 20 is rotated one revolution while imaging the radius of the wafer W with the scanning unit 52 to image the entire surface of the wafer W, and according to the obtained imaging Image to determine the presence or absence of scratches.

Here, referring to FIG. 3, the scratch detection equipment of the present embodiment will be described. FIG. 3 is a schematic top view showing an example of photographing the upper surface of the wafer after grinding. Specifically, FIG. 3A shows a wafer imaging of a comparative example, and FIG. 3B shows an example of wafer imaging of this embodiment.

As shown in FIG. 3, the upper surface of the wafer W after grinding is formed with innumerable regular arc-shaped scratches from the center of the wafer W toward the outer periphery. In the example shown in FIG. 3A, the scanning part 60 corresponding to the diameter of the wafer W is positioned above the wafer W. In the example shown in FIG. The scanning unit 60 extends in the Y-axis direction. The scanning unit 60 captures the entire surface of the wafer W by moving (scanning) relative to the wafer W in the X-axis direction while irradiating light toward the wafer W.

In this case, with respect to the center line C along the X-axis direction of the wafer W, the scratches (for example, scratch S1) formed on the area on the left side of the paper and the scratches formed on the area on the right side of the paper ( For example, the scratch S2) will cause the irradiated direction of light to be different with respect to the scanning direction of the scanning unit 60.

In this way, it is conceivable that the light irradiation to the scratch becomes uneven due to the position of the scratch, and therefore, an appropriate captured image cannot be obtained. For example, in FIG. 3A, by changing the direction of light irradiation on the left and right sides of the paper, the center position of the wafer W may be shifted.

In contrast, in the present embodiment shown in FIG. 3B, the scanning portion 52 is arranged on the upper surface of the wafer W at a length and position corresponding to the radius of the wafer W. As shown in FIG. The scanning unit 52 photographs the wafer W by rotating the wafer W once while irradiating light on the wafer W to cover the entire surface. In this case, the light irradiated to the scratch S can always be uniformly formed. As a result, the center of the wafer W will not be shifted, and an appropriate photographed image of the wafer W can be obtained.

In addition, as the details will be described later, by performing coordinate conversion on the image captured by the scanning unit 52 to make it easier to see the scratches, it becomes possible to easily and appropriately detect the scratches.

Next, the scratch detection method of this embodiment will be described with reference to FIGS. 4 to 6. Fig. 4 is a schematic diagram showing an example of the imaging procedure of the present embodiment. FIG. 4A is a view seen from arrow A in FIG. 1, and FIG. 4B is a view seen from arrow B in FIG. 1. Fig. 5 is a schematic diagram showing an example of the editing procedure of the present embodiment. Fig. 5A is a photographed image before editing, and Fig. 5B is a strip image after editing. Fig. 6 is a schematic diagram showing a specific example of scratch detection.

The scratch detection method of this embodiment is implemented by an imaging step (refer to FIG. 4), an editing step (refer to FIG. 5), and a judgment step (refer to FIG. 6). The imaging step is to photograph the ground wafer For the ground surface of W, the editing step is to perform coordinate conversion on the captured image of the wafer W and edit it into a strip image, and the judgment step is to judge whether there is a scratch based on the strip image after editing.

First, the imaging procedure will be explained. As shown in FIG. 4A, the wafer W after the grinding process is positioned under the scanning unit 52 in a state of being sucked and held on the work chuck 20 as it is. In addition, the work chuck table 20 adjusts the inclination of the rotating shaft by an unshown tilt adjustment mechanism so that the extension direction of the scanning portion 52 (line sensor 53) and the upper surface (holding surface) of the wafer W 21a) Become parallel.

As shown in FIGS. 4A and 4B, the imaging area of the line sensor 53 is equivalent to the radius of the wafer W directly below the line sensor 53. The light source 54 irradiates light toward the imaging area of the line sensor 53. The scanning unit 52 obtains the wafer by rotating the wafer W on the work chuck 20 one turn while photographing the radius of the wafer W irradiated by the light of the light source 54 with the linear sensor 53 W captured image of the entire surface. Furthermore, the light irradiated by the light source 54 has a wavelength that is reflected on the surface of the wafer W, and light of a wavelength that is transparent to the wafer W is not used.

Next, the editing procedure will be explained. In the captured image obtained in the imaging step, as shown in FIG. 5A, the reflected light of the imaging light becomes weaker (scattered) due to the fine unevenness formed by the scratch, so the scratch can be identified from the contrast of light and dark. . In the editing step, the captured image shown in FIG. 5A is subjected to coordinate conversion and edited into an image (the band-shaped image shown in FIG. 5B) that can easily determine the presence or absence of scratches by the judging section 57 (refer to FIG. 1) .

Specifically, the editing unit 56 (refer to FIG. 1) sets the radial direction (from the center of the wafer to the outer periphery of the wafer) of the captured image in FIG. 5A as the vertical axis, and sets the circumferential direction of the captured image (0° to 360°) is set as the horizontal axis to implement coordinate conversion. The edited image obtained by the coordinate conversion, as shown in FIG. 5B, is represented by a rectangular image (band-shaped image) that is longer in the circumferential direction. For example, as shown in FIG. 5A thick line of scratch S, in the band image of FIG. 5B, the bold line is represented by S _A scratches.

In this way, in contrast to the actual captured image, the scratch is represented by an arc-shaped curve, and in the edited strip image, the scratch is represented by a substantially straight line with regularity. Thereby, in the subsequent determination step, the determination part 57 becomes easy to determine the presence or absence of a scratch.

Next, the judgment procedure will be explained. The judging step is to judge the presence or absence of scratches based on the strip image obtained in the editing step. Specifically, the judging unit 57, in the strip image, if the width of the regular straight line is greater than the preset width, it is judged as scratched, and if the regular straight line is within the preset width It is judged that there is no scratch below. In addition, the judgment unit 57 judges that there is a scratch even when a line other than a regular straight line appears in the strip image.

Contemplated example, as shown, belt-shaped image, along with the regularity of the straight line displayed a relatively thick case of the straight line S _B 6A. Analyzing unit 57, a detection width D S _B from the straight belt-shaped image, and a straight line with a predetermined width of the presence or absence of scratch determination reference for comparison. As a result, the case of large width S _B of the straight line, the straight line S _B S _B identified as scratches. That is, the judgment unit 57 judges that there is a scratch.

Also, as another example and 6B, the belt-shaped image is displayed formed into a straight line with respect to the case of a straight line intersecting the regularity of S _C, the determination unit 57 will be identified as the linear blade S _C Mark S _C. That is, in this case, the judgment unit 57 also judges that there is a scratch.

In this way, in the present embodiment, even in the case where a regular scratch like a grinding mark is displayed in the captured image, relatively large scratches can still be detected from the edited strip image Or scratches without regularity. That is, it is possible to select and judge the scratches that will affect the subsequent steps or the components formed on the wafer W.

Furthermore, if it is determined that there are scratches as described above, the re-grinding step can be performed to remove the scratches that will become a problem later. According to this, it is possible to implement a series of steps of grinding, scratch detection, and scratch removal with a single grinding device 1. Thereby, it is possible to save the time and effort of transporting the wafer W to another device for scratch detection or scratch removal.

As described above, according to the present embodiment, it is possible to obtain a photographed image of the entire surface of the wafer by rotating the work chuck table 20 while photographing the radius of the wafer W with the line sensor 53. Since the light source 54 illuminates the radius of the wafer W during shooting, the presence or absence of scratches can be judged from the brightness of the captured image. In particular, by editing the captured image into a strip image, the scratch can be represented by a regular straight line. Therefore, the width of the straight line can be easily compared with the width of the straight line set in advance. In addition, lines other than straight lines with regularity can be easily found. As a result, it is easy to judge the presence or absence of scratches. According to this, it is possible to appropriately detect scratches with a simple configuration without requiring a complicated optical system configuration.

In addition, in the present embodiment, although the work chuck table 20 is rotated one turn to take an image of the entire surface of the wafer W, it is not limited to this structure. For example, the scanning unit 52 may be rotated about the center of the wafer W as an axis.

In addition, in this embodiment, although the scanning part 52 is provided with the structure which extended by the length corresponding to the radius part of the wafer W, it is not limited to this structure. The scanning part 52 (the line sensor 53 and the light source 54) may also be shorter than the radius of the wafer W. When the radius of the scanning unit 52 is shorter than that of the wafer W, the scanning unit 52 can be moved away from the wafer W to take pictures to detect scratches, or the scanning unit 52 can be moved closer to the wafer W and placed on the wafer W. Move in the radial direction to photograph the entire surface of the wafer and detect scratches. In this way, the distance between the scanning part 52 and the wafer W may be adjusted. Moreover, if the scanning part 52 is shorter, a lower-priced scanning part 52 can be selected.

In addition, although the present embodiment and modification examples have been described, as other embodiments of the present invention, the above-mentioned embodiment and modification examples may be combined in whole or in part.

In addition, the embodiment of the present invention is not limited to the above-mentioned embodiment, and various changes, substitutions, and modifications may be made within the scope not departing from the technical idea of the present invention. In addition, if the technical idea of the present invention can be realized in other ways through technological progress or other derived technologies, this method can also be used to implement it. Therefore, the scope of the patent request covers all embodiments that can be included in the scope of the technical idea of the present invention. Industrial availability

As explained above, the present invention has the following effects: it is possible to appropriately detect scratches with a simple configuration without requiring the configuration of a complicated optical system; and especially for grinding the surface of a wafer. It is useful on the cutting device.

1‧‧‧Grinding device 10‧‧‧Abutment 11‧‧‧Moving plate 12‧‧‧Waterproof cover 15‧‧‧Support 20‧‧‧Working clamp 21‧‧‧Perforated plate 21a‧‧‧Retaining surface 22 ‧‧‧Frame body 23‧‧‧Circular recessed part 24‧‧‧Worktable rotating equipment 30‧‧‧Grinding and feeding equipment 31‧‧Guide 32‧‧‧Z-axis worktable 33‧‧‧Ball screw 34‧ ‧‧Drive motor 40‧‧‧Grinding equipment 41‧‧‧Housing 42‧‧‧Spindle unit 44‧‧‧Spindle 45‧‧‧Mount 46‧‧‧Grinding wheel 47‧‧‧Grinding stone 47a ‧‧‧Grinding surface 50‧‧‧Scratch detection equipment 51‧‧‧Vertical part 52‧‧‧Scanning part 53‧‧‧Line sensor 54‧‧‧Light source 55‧‧‧Judging equipment 56‧‧ ‧Editor 57‧‧‧Judgment 60‧‧‧Scan 90‧‧‧Control equipment A, B‧‧‧Arrow C‧‧‧Center line D‧‧‧Width T‧‧‧Protection tape W‧‧‧ Wafer X, Y, Z‧‧‧direction S, S ₁ , S ₂ , S _A ‧‧‧ Scratch S _B , S _C ‧‧‧Straight line (scratch)

Fig. 1 is a perspective view of the grinding device of this embodiment. Fig. 2 is a schematic diagram of the time when a wafer is ground (grinding step) on the grinding device of the present embodiment. 3A and 3B are schematic top views showing examples of photographing the upper surface of the wafer after grinding. 4A and 4B are schematic diagrams showing an example of the imaging procedure of this embodiment. 5A and 5B are schematic diagrams showing an example of the editing procedure of this embodiment. 6A and 6B are schematic diagrams showing specific examples of scratch detection.

20‧‧‧Working Clamping Table

21‧‧‧Perforated plate

21a‧‧‧Keep the surface

22‧‧‧Frame

23‧‧‧Circular recess

24‧‧‧Workbench rotating equipment

52‧‧‧Scanning Department

53‧‧‧Line sensor

54‧‧‧Light source

T‧‧‧Protective tape

W‧‧‧wafer

X, Y, Z‧‧‧direction

Claims (1)

A grinding device is a grinding device provided with a grinding device, a holding device, and a scratch detection device. The grinding device is provided with a mounting seat on which a grinding wheel is installed and has an axis with the center of the grinding wheel as the axis. A rotating spindle unit, wherein the grinding wheel is provided with a grinding grindstone in a ring shape, and the holding device is provided with a mechanism for rotating the work chuck with the center of the wafer held by the holding surface of the work chuck as the axis Table rotating equipment, the holding surface of the work chuck table is formed as an inclined surface whose outer circumference becomes lower with the center as the apex, and the grinding equipment makes the grinding grindstone rotated by the spindle unit The center of the wafer held by the work chuck is ground in the radius area between the center and the outer periphery of the wafer and in the ground part of the arc. The scratch detection equipment is equipped with the radius of the wafer to be photographed. The linear sensor of the radius length, a light source extending at the same length as the linear sensor, and a judging device, the judging device comprising: an editing section, the radius of the photographed image taken by the linear sensor The direction is set as the vertical axis and the circumferential direction is set as the horizontal axis to edit into a strip-shaped image; and the judging section, in the strip-shaped image edited by the editing section, if the width of the regular straight line is greater than the preset If the width is larger, or there is a line other than the straight line with the regularity, it is judged as scratched. If the width of the straight line with the regularity is below the preset width, it is judged as no scratch.

Images