TW201834051A - Workpiece inspection method, workpiece inspection device and processing device more appropriately and easily detecting a grinding trace of a workpiece - Google Patents

Abstract

To more appropriately and easily detect a grinding trace of a workpiece. The method comprises: a processing step of processing a workpiece with a grinding wheel or a polishing pad, a projection step of irradiating light from a light source to a surface to be processed of the workpiece, such that light reflected by the surface to be processed irradiates the screen to project the projection image on the screen while reflecting the state of the unevenness formed on the surface to be processed in the processing step, an imaging step of imaging the projection image of the screen to form a captured image, and an judging step of judging the quality of the workpiece by knowing the unevenness state of the workpiece based on the captured image.

Description

Workpiece inspection method, workpiece inspection device and processing device

The invention relates to an inspection method, an inspection device and a processing device for inspecting grinding marks formed on a workpiece.

Processing methods such as grinding various flat-shaped workpieces made of silicon, SiC, sapphire and the like with a grinding grindstone or grinding with a polishing pad have been known. The grinding stone is formed by fixing abrasive grains such as diamond with a bonding material such as resin or metal. In addition, the polishing pad composed of a non-woven cloth or a urethane pad is used together with abrasive grains to polish the surface to be polished of a workpiece.

In a grinding process using a grinding grindstone or a grinding process using a grinding pad, the grinding grindstone or the grinding pad is brought into contact with a workpiece to perform processing. In this kind of processing, the abrasive particles falling from the grinding stone, the grinding chips from the workpiece, or the aggregated abrasive particles may enter between the grinding stone or the polishing pad and the workpiece. Deep and long grinding marks (scratches) are formed on the workpiece.

If a workpiece having the grinding marks formed is divided to form each element wafer, the flexural strength of the element wafer is reduced. Therefore, some people have proposed the following methods: take pictures of the workpiece during or after processing to detect the grinding marks, or irradiate the workpiece with laser light to detect the grinding marks based on the intensity of the reflected laser light. [Habitual technical literature] [patent literature]

[Patent Document 1] Japanese Patent Application Publication No. 2016-49581 [Patent Document 2] Japanese Patent Application Publication No. 2010-17792

[Problems to be Solved by the Invention] However, no matter which method is implemented, the configuration of a device capable of detecting grinding marks is complicated, and the high cost of the device is a problem.

The present invention has been made in view of the problem of opening, and an object of the present invention is to provide a work piece inspection method and a work piece that can more appropriately and more appropriately detect irregularities such as grinding marks (scratches) formed on a work surface of a work piece. Inspection equipment and processing equipment. [Technical means to solve the problem]

According to a first aspect of the present invention, there is provided a method for inspecting a workpiece, which is characterized by comprising: a processing step for processing the workpiece with a grinding stone or a polishing pad; a projection step for irradiating light from a light source on the workpiece The processed surface, and the light reflected by the processed surface reaches the screen, thereby projecting an image reflecting the state of the unevenness formed on the processed surface in the processing step onto the screen; the imaging step, The projection image of the screen is captured to form a captured image; and the determining step is to grasp the uneven state of the workpiece based on the captured image, and then determine whether the workpiece is good or bad.

According to a second aspect of the present invention, there is provided a method for inspecting a workpiece, which is characterized by comprising: a processing step for processing the workpiece with a grinding stone or a polishing pad; and an imaging step for irradiating light from a light source on the workpiece The processed surface is photographed, and the light reflected from the processed surface is captured to form a captured image, and the captured image is written into an image reflecting the state of unevenness formed on the processed surface in the processing step ; And a determining step of grasping the uneven state of the workpiece based on the captured image, and then determining whether the workpiece is good or bad.

According to a third aspect of the present invention, there is provided a method for inspecting a workpiece related to the first aspect or the second aspect of the present invention, which is characterized in that: the camera image is written into the image including the center of the processed surface. A central region of the processed surface, and in the captured image, no peripheral region of the processed surface surrounding the central region is written.

According to a fourth aspect of the present invention, there is provided an inspection device for a workpiece, which is provided with a holding table for holding the workpiece in a state in which a workpiece to be processed by a grinding stone or a polishing pad is exposed; a light source, The light is irradiated on the processed surface of the workpiece held by the holding table; the screen is irradiated by the light reflected by the processed surface, thereby reflecting the processed surface reflecting the workpiece by the processing office. A projection image of the formed unevenness; and an imaging unit for imaging the projection image projected on the screen to form a captured image.

According to a fifth aspect of the present invention, there is provided an inspection device for a workpiece, which is characterized by comprising: a holding table for holding the workpiece in a state where a workpiece to be processed by a grinding stone or a polishing pad is exposed; a light source, The light is irradiated on the processed surface of the workpiece held by the holding table; and the camera unit detects the light reflected from the processed surface to form a captured image.

In the fourth aspect and the fifth aspect of the present invention, the workpiece inspection device may further include: a determination unit that grasps the uneven state of the workpiece based on the captured image, and further determines whether the workpiece is good or bad Or not. The determining unit may determine the workpiece as a defective product when the continuous unevenness is detected in a central region including the center of the surface to be processed and an outer peripheral region surrounding the central region.

In the fourth aspect and the fifth aspect of the present invention, the captured image may be written in a central area of the processed surface including the center of the processed surface; A peripheral area of the processed surface surrounding the central area is written.

One aspect of the present invention is also a processing device, which is characterized by: a chuck table that holds a workpiece; a processing unit that uses the grinding stone or the polishing pad to process the workpiece held by the chuck table; The cleaning unit is used to clean the processed surface of the processed workpiece; and the inspection unit is used to check the uneven state of the processing marks formed on the processed surface of the cleaned workpiece; wherein, the inspection unit, It is an inspection device for a workpiece related to the present invention. [Inventive effect]

According to the inspection method, inspection device and processing device related to one aspect of the present invention, based on the captured image using a simple structure including a light source, a screen, or a concave mirror, it is possible to grasp the processing surface of the workpiece formed by processing. Grinding unevenness such as scratches (scratches). In this imaging of the captured image, light that is irradiated from the light source onto the work surface of the workpiece and is reflected from the work surface is used.

When unevenness is formed on the work surface of the workpiece due to processing, an image that emphasizes the unevenness state is written in a captured image formed by irradiating light reflected from the work surface. Therefore, it is possible to easily grasp the state of the unevenness formed on the machined surface, and it is easy to inspect the workpiece. When it is confirmed that the processed surface of the workpiece has unevenness that exceeds the allowable level, the workpiece can be judged as a defective product and the processing can be stopped to check the state of the grinding stone or polishing pad.

Therefore, according to one aspect of the present invention, a work piece inspection method, a work piece inspection device, and a machining device that can more appropriately and more easily detect irregularities such as grinding marks (scratches) formed on a work surface of a work piece are provided. .

Embodiments related to one aspect of the present invention will be described with reference to the drawings. FIG. 1 (A) is a perspective view schematically showing a workpiece inspection method, a workpiece inspection device, or a workpiece in a processing device according to an embodiment of the present invention.

In FIG. 1 (A), the workpiece 1 is schematically shown. The workpiece 1 is, for example, a substrate made of silicon, SiC (silicon carbide), other semiconductors, or materials such as sapphire, glass, and quartz.

The surface 1 a of the workpiece 1 is divided into a plurality of regions by a plurality of predetermined division lines (cutting grooves) 3 arranged in a grid pattern, and elements 5 such as ICs are formed in the regions divided by the plurality of predetermined division lines 3. Finally, the workpiece 1 is divided along the dicing groove 3 to form each element wafer.

Next, the protective tape adhered to the surface 1a of the workpiece 1 will be described using FIG. 1 (B). In FIG. 1 (B), the protective tape 7 is shown typically. The protective tape 7 has a function of protecting the elements 5 and the like formed on the surface 1 a of the workpiece 1. The protective tape 7 protects the surface 1a side of the workpiece 1 from punching caused when the back surface of the workpiece 1 is processed or transported, and prevents the element 5 from being damaged.

The protective tape 7 includes a flexible film-like base material and a sticky layer (adhesive layer) formed on one surface of the base material. For example, the substrate uses PO (polyolefin). PET (polyethylene terephthalate), polyvinyl chloride, polystyrene, etc., which have higher rigidity than PO, can also be used. The adhesive layer (adhesive layer) is made of, for example, silicone rubber, acrylic material, epoxy material, or the like.

Next, a processing device incorporating an inspection device for inspecting the uneven workpiece 1 will be described. FIG. 2 is a perspective view schematically showing a grinding device as a configuration example of a processing device including an inspection device.

The grinding device 2 includes, on a slightly rectangular parallelepiped base 4, a chuck table 8 mounted on a disc-shaped rotary table 6, a grinding unit 10, and a grinding unit 10 a. A pillar 12 and a pillar 12 a are erected at the rear of the abutment 4. The pillar 12 and the pillar 12 a are respectively provided with a grinding unit 10 and a grinding unit 10 a.

The base 4 is provided with a disc-shaped rotary table 6 that can rotate in the horizontal plane. The upper surface of the rotary table 6 is provided with three chuck tables 8 spaced 120 degrees apart in the circumferential direction. By the rotation of the rotary table 6, each chuck table 8 is positioned in the work loading and unloading area, the first grinding area, 2nd grinding area. In the first grinding area, for example, rough grinding is performed, and in the second grinding area, for example, fine grinding is performed.

The chuck table 8 has a suction channel (not shown) connected at one end to a suction source (not shown), and the other end of the suction channel is connected to the holding surface 8 a on the chuck table 8. The holding surface 8a is composed of a porous member, and the negative pressure generated by the suction source acts on the workpiece 1 placed on the holding surface 8a through the porous member, so that the chuck table 8 attracts and holds the workpiece.

The grinding unit 10 includes a grinding stone 18 held by a grinding wheel 16 which is rotationally driven by a spindle motor 14. The grinding unit 10a includes a grinding stone 18a held by a grinding wheel 16a that is rotationally driven by a spindle motor 14a. The grinding wheels 18, 18a held by the grinding wheels 16, 16a are moved up and down by the processing feed units 20, 20a to contact the workpiece 1 held on the chuck table 8, and the workpiece 1 is ground into a predetermined shape. thickness of.

The front portion of the base 4 is higher than the portion on which the rotary table 8 is provided, and the cassette mounting bases 22 and 22a are fixed to the front end of the base 4. The cassette mounting table 22 mounts a cassette 22 that stores the workpiece 1 before grinding and processing, and the cassette mounting table 22 a mounts a cassette 24 a that stores the workpiece 1 after grinding.

The work transfer robot arm 26 is mounted on the base 4 adjacent to the cassette mounting tables 22 and 22a. The front part of the abutment 4 is further equipped with a positioning table 28 having a plurality of positioning pins, a work-in mechanism (loading arm) 30, a work-out mechanism (unloading arm) 32, and a rotation for cleaning and rotating drying of the ground workpiece洗 装置 34。 Washing device 34.

The grinding device 2 includes an inspection device 36 according to the present embodiment between the rotary cleaning device 34 and the cassette mounting table 22a. The inspection device 36 includes a holding table 38 that holds the workpiece 1 to be inspected, a light source 40, a screen 42, and an imaging unit 44.

Above the holding table 38, a light source 40 is arranged to emit light to the entire workpiece 1 held by the holding table 38. As the light source 40, for example, an incandescent light bulb or an LED is used. However, the type, position, and the like of the light source 40 are not limited. The light may be parallel light or non-parallel light. If the light is parallel light, for example, an optical element such as a concave mirror may be combined with the light source 40. In addition, a light source having a small light emitting area and being regarded as a point light source may be used to obtain parallel light or non-parallel light.

On the path (light path) of the light reflected by the workpiece 1, a screen 42 is formed by irradiating the reflected light to form a projection image. The screen 42 is typically a flat screen, and is formed to have a size substantially the same as that of the work 1 or a size capable of displaying the center area of the work. The unevenness formed by machining on the surface to be processed easily passes through the center area of the workpiece. Therefore, if a screen with a diameter of about 50 mm near the center of the workpiece can be projected, it is easier to confirm the unevenness state.

In the present embodiment, the light source 40 is arranged diagonally above the holding table 38, and the screen 42 is arranged on the path of the light reflected by the workpiece 1. When the workpiece 1 is radiated with light advancing obliquely downward from the light source 40, the light will be reflected by the exposed surface (here, the back surface 11b) of the workpiece 1 and illuminate the screen 42. As a result, a projection image reflecting the state of the exposed surface (that is, the back surface 1 b) of the workpiece 1 is formed on the screen 42.

At a position where the screen 42 can be seen, an imaging unit (imaging means) 44 configured to capture a projection image formed on the screen 42 to form a captured image is disposed. The imaging unit 44 is a digital camera that combines an imaging element such as a CCD or CMOS with an optical element such as a lens, and outputs a captured image (image) formed by capturing a projection image to the outside. In addition, as the imaging unit 44, either a digital still camera that forms a still image or a digital camera that forms an animation can be used.

Here, the tilt angle of the screen 42 will be described with reference to FIG. 4. In FIG. 4, the relevant positions of the light source 40, the workpiece 1, the screen 42, and the camera unit 44 are schematically shown. As shown in FIG. 4, it is preferable that the light reflected from the back surface 1 b of the workpiece 1 is incident on the screen 42 perpendicularly, thereby tilting the screen 42.

That is, the screen 42 is tilted so that the angle of the light incident on the workpiece 1 and the back surface 1b, the angle of the reflected light and the back surface 1b, and the tilt angle of the vertical surface of the back surface 1b of the workpiece 1 and the screen 42, Consistent (that is, the three angles are consistent). In this case, since a minute projection image that is extremely deformed can be projected on the screen 42, it is possible to more accurately grasp the state of the unevenness formed on the back surface 1b of the workpiece 1. At this time, in order to make the captured image formed by the imaging unit 44 clear, the depth of field of the imaging unit 44 needs to be appropriately adjusted.

The imaging unit 44 is connected to a determination unit (not shown). The imaging unit 44 is used for confirming the state of irregularities formed on the processed surface (back surface 1b) of the workpiece 1 by processing the captured image output from the imaging unit 44. Whether the workpiece 1 is good or bad is determined based on the uneven state.

The inspection device 36 may be provided with a concave mirror instead of the screen 42. If a concave mirror is provided instead of the screen 42, the light reflected from the processed surface of the workpiece 1 can be focused on the imaging unit 44 by the concave mirror. Therefore, the amount of light reaching the imaging unit 44 increases, and the imaging unit 44 can form a clearer captured image.

In addition, the processing device according to this embodiment is not necessarily a grinding device for grinding a workpiece by a grinding unit having a grinding stone, but may be a grinding device for grinding a workpiece by a grinding unit provided with a polishing pad.

Next, a method for inspecting a workpiece according to this embodiment performed by the inspection device 36 provided in the grinding device 2 will be described. In this inspection method, first, a processing step of processing a workpiece with a grinding stone or a polishing pad is performed.

This processing step will be described with reference to FIGS. 3 (A) and 3 (B). FIG. 3 (A) is a side view schematically showing a grinding process, and FIG. 3 (B) is a side view schematically showing a grinding process.

First, as shown in FIG. 3 (A), the case where the grinding process of the back surface 1b side of the workpiece 1 by the grinding unit 10 provided in the grinding apparatus 2 is demonstrated. The workpiece 1 is placed on the holding surface 8 a of the chuck table 8 with the protective tape 7 in a state where the surface 1 a side faces downward. Next, the workpiece 1 is sucked and held on the chuck table 8, and the back surface 1 b side of the workpiece 1 is exposed upward. The rotating table 6 (see FIG. 2) of the grinding device 2 is rotated to position the chuck table 8 below the grinding unit 10.

Next, the spindle motor 14 of the grinding unit 10 is operated to rotate the grinding wheel 16. In addition, the chuck table 8 is rotated around an axis perpendicular to the holding surface 8a. Next, the processing feed unit 20 is operated to lower the grinding wheel 16 toward the workpiece 1. When the grinding grindstone 18 mounted on the rotating grinding wheel 16 touches the back surface 1b side of the workpiece 1, the workpiece 1 is ground. machining. When the grinding stone 18 is positioned at a predetermined height position by the processing feed unit 20, the workpiece 1 is thinned to a predetermined thickness.

In addition, in the processing steps, as shown in FIG. 3 (B), the back surface 1b side of the workpiece 1 may be polished by the polishing unit 10b. This grinding unit 10b is provided in the grinding apparatus 2 instead of the grinding unit 10a of the grinding apparatus 2 shown in FIG. 2, for example. The polishing unit 10b may be provided in a polishing device that does not include a grinding unit.

The polishing unit 10b includes a polishing pad 18b mounted on a polishing wheel 16b. A spindle motor (not shown) connected to the grinding wheel 16b at one end and connected to the other end of the spindle is operated to rotate the grinding wheel 16b.

When grinding is performed by the grinding unit 10b, the workpiece 1 is placed on the holding surface 8a of the chuck table 8 through the protective tape 7 with the protective tape 7 facing the chuck table 8 side of the workpiece 1 in the same manner as the above-mentioned grinding process. on. Next, the workpiece 1 is sucked and held on the chuck table 8, and the back surface 1 b side of the workpiece 1 is exposed upward.

Next, the grinding wheel 16 b is rotated, the chuck table 8 is rotated around an axis perpendicular to the holding surface 8 a, and the grinding wheel 16 b is lowered toward the workpiece 1. When the polishing pad 18b mounted on the polishing wheel 16b touches the back surface 1b side of the workpiece 1, a polishing process is performed.

During the grinding process using the grinding stone 18 or the grinding process using the polishing pad 18b, the abrasive particles falling from the grinding stone 18, the grinding chips or the aggregated abrasive particles ground from the workpiece 1, may enter the grinding stone 18 or Between the polishing pad 18 b and the workpiece 1, if machining is continued, deep and long grinding marks (scratch marks) will be formed on the workpiece 1. If the workpiece 1 formed by the grinding marks is divided to form each element wafer, the flexural strength of the element wafer will be reduced, and it will not function as an element and become defective.

Therefore, in the method for inspecting a workpiece according to this embodiment, a projection step, an imaging step, and a judging step are subsequently performed to grasp the uneven state such as a grinding mark (scratch) formed on the processed surface of the workpiece 1 to determine the Good or bad.

In the projection step, light is irradiated onto the processed surface of the processed workpiece 1, and the reflected light is projected on the screen. First, the processed workpiece 1 is moved from the chuck table 8 to the holding table 38 of the inspection device 36 (see FIG. 2). In this process, the processed surface of the workpiece 1 is cleaned by the rotary cleaning device 34. The workpiece 1 is placed on the holding table 38 via the protective tape 7 with the front surface 1a side of the workpiece 1 facing the holding table 38, and the processed surface (back surface 1b) is exposed upward.

Next, as shown in FIG. 4, light 46 is emitted from the light source 40. The light source 40 is provided in a state where the light 46 can irradiate the entire workpiece 1 held by the holding table 38 (position, orientation, etc.). Therefore, the light 46 emitted from the light source 40 is reflected by the processed surface (back surface 1b) of the workpiece 1.

A screen 42 is arranged on the path of the light 46 reflected by the workpiece 1. Therefore, the light 46 reflected by the processed surface (back surface 1b) of the workpiece 1 is irradiated on the screen 42 to form a projection image corresponding to the state of the unevenness formed by the processing on the processed surface. Here, when the angle formed by the light 46 reflected by the workpiece 1 and the back surface 1 b coincides with the inclination angle of the screen 42 and the vertical plane of the processed surface of the workpiece 1, the distortion of the projection image becomes extremely low.

After that, an imaging step is performed. This projection image is captured by the imaging unit 44 to form a captured image. At this time, in order to make the captured image clear, the depth of field of the camera unit (camera) 44 is appropriately adjusted. Next, the captured image formed by the imaging unit 44 is sent to a determination unit (not shown).

After the image capturing step, a determining step is performed: according to the captured image formed by the image capturing unit 44 to grasp the uneven state of the workpiece, and then determine whether the workpiece is good or bad. In this embodiment, the projection image written in the captured image formed by the imaging unit 44 of the inspection device 36 is projected on the screen 42 instead of the processed surface (back surface 1b) of the workpiece 1.

The projection image is an image formed by the light 46 irradiated on the work surface of the workpiece being reflected by the work surface and irradiating the screen 42. Here, the surface to be processed is substantially a mirror surface, and light 46 is specularly reflected on the surface to be processed. However, when a slight unevenness is formed on the surface to be processed, the light 46 is partially diffused or converged due to the unevenness.

Therefore, the projected image will be a light-dark contrast image reflecting the state of the minute unevenness formed on the processed surface. In addition, this type of projection of light reflected by a mirror on a screen or the like, which reflects the convex and concave state of the mirror in the formed image, is called a magic mirror image. Next, compared with a captured image formed by directly photographing the processed surface, a captured image formed by photographing a projection image projected on the screen 42 is more effective for grasping the formed image on the processed surface. Uneven state. Therefore, the concave-convex state is emphasized by the magic mirror display.

Therefore, it is possible to more easily grasp the uneven state of the workpiece according to the captured image written in the projection image. For example, when unevenness is not formed on the processed surface, the brightness of the entire processed surface written in the captured image is the same. In addition, for example, when unevenness is formed on the processed surface, a light and dark pattern that emphasizes the state of the unevenness formed on the processed surface appears in the projection image written in the captured image. That is, the uneven state of the work can be grasped from the captured image.

However, a determination unit (not shown) connected to the imaging unit 44 has previously registered a condition: this condition is used to determine whether the workpiece 1 can be sufficiently secured based on the unevenness of the processed surface grasped from the captured image. Flexural strength. This determination unit judges the work 1 as a good product when the bending strength of the work 1 is sufficient. On the other hand, the determination unit determines the work 1 as a defective product when the flexural strength of the work 1 is insufficient due to the unevenness formed on the processed surface of the work 1.

For example, the determination unit determines the workpiece 1 as a defective product when a continuous unevenness (processing trace) is detected in a central region of the workpiece 1 including the center of the surface to be processed and a peripheral region surrounding the central region. Here, the central area refers to, for example, a circular area at a distance of about one-third to one-fourth of the radius of the workpiece from the center of the processed surface; the peripheral area refers to the central area of the processed surface Outside the area.

The continuous unevenness (processing marks) of the central area and the peripheral area is difficult to form under normal processing. If such unevenness is detected, it can be determined that some abnormality has occurred in the processing device, so the determination unit will detect the abnormality The uneven workpiece 1 was determined to be defective.

When the judging unit judges the workpiece 1 as a defective product, the workpiece 1 will not be sent to a subsequent process and can be discarded. Next, when it is determined that the unevenness formed on the processed surface is caused by the processing in the processing step, the processing conditions and the like in the processing step are checked. Or, check whether there are any abnormalities such as grinding stones or polishing pads.

If the above-mentioned method for inspecting a workpiece is implemented, it is possible to easily comprehend the irregularities such as processing marks (scratches) formed on the machined surface of the workpiece 1 due to processing, according to the captured image formed by a simple configuration.

Furthermore, in the above-mentioned embodiment, the light is directly irradiated to the workpiece 1 from the light source, but the light emitted from the light source may be irradiated to the concave mirror, and the parallel light reflected by the concave mirror may be irradiated to the workpiece 1. This case will be described using FIG. 5 (A).

FIG. 5 (A) is a diagram schematically showing a configuration example of the inspection device 36a. The inspection device 36a shown in FIG. 5 (A) includes a light source 40a, a concave mirror 48a, a holding table 38a, a screen 42a, an imaging unit 44, and a personal computer 50.

In this inspection device 36a, the light emitted from the light source 40a is irradiated onto the concave mirror 48a. The concave mirror 48a reflects the parallel light toward the workpiece 1 held by the holding table 38a. When the workpiece 1 is irradiated with the parallel light, the parallel light is reflected toward the screen 42a, and a projection image reflecting the uneven state of the workpiece is formed on the screen 42a. The imaging unit 44 forms the projection image, and sends the captured image to the personal computer 50. The personal computer 50 has a function as a determination unit, and grasps the uneven state of the workpiece based on the captured image, and further determines whether the workpiece is good or bad.

In the above embodiment, a projection image is formed by irradiating the light reflected by the workpiece 1 on the screen, and the imaging unit captures the projection image to form a captured image. However, a concave mirror may be provided instead of the screen, so that the light reflected by the workpiece 1 is irradiated to the concave mirror, and the light is focused toward the imaging unit. This case will be described using FIG. 5 (B).

FIG. 5 (B) is a diagram schematically showing a configuration example of the inspection device 36b. The inspection device 36b shown in FIG. 5 (B) includes a light source 40b, a concave mirror 48b, a holding table 38b, a concave mirror 48c, an imaging unit 44, and a personal computer 50.

In this inspection device 36b, the light emitted from the light source 40b is irradiated onto the concave mirror 48b. The concave mirror 48b reflects the parallel light toward the workpiece 1 held by the holding table 38b. When the workpiece 1 is irradiated with the parallel light, the parallel light is reflected toward the concave mirror 48c, and the concave mirror 48c reflects and focuses the parallel light irradiated on the concave mirror 48c toward the imaging unit 44. The imaging unit 44 detects the light reflected by the concave mirror 48c.

The camera unit 44 sends the captured image obtained by the camera to the personal computer 50. The personal computer 50 has a function as a determination unit, and grasps the uneven state of the workpiece based on the captured image, and further determines whether the workpiece is good or bad. Here, the captured image is not an image captured by projecting an image formed by illuminating the light reflected by the workpiece 1 on the screen, but the light is reflected by the concave mirror 48c and condensed by the light of the imaging unit 44. Make up the captured image directly.

The light reflected by the workpiece 1 is focused on the camera unit 44, so the amount of light reaching the captured image increases, and the obtained captured image is clearer. Therefore, the uneven state of the machined surface of the workpiece 1 can be evaluated more accurately, and the personal computer 50 functioning as the determination unit can be made to perform finer determination.

In addition, light is made incident perpendicularly on the back surface 1b of the workpiece 1, and the reflected light is captured by a camera unit 44 disposed on the front surface of the back surface 1b of the workpiece 1, thereby obtaining a photographed image without distortion. An inspection apparatus 36c that can obtain a captured image without distortion will be described with reference to FIG. 6. FIG. 6 is a diagram schematically showing a configuration example of the inspection device 36c.

The inspection device 36c includes a light source 40c, a beam splitter 52, and an imaging unit 44. The light emitted from the light source 40c becomes parallel light by the lens 56a between the light source 40c and the beam splitter 52. When the parallel light enters the beam splitter 52 disposed on the front surface of the workpiece 1 held by the holding table 38c, a part of the parallel light is reflected toward the workpiece 1.

Then, as shown in FIG. 6, the light is incident from the front toward the back surface 1 b of the work 1. At this time, the entire back surface 1b of the workpiece 1 may not be irradiated with the light, and for example, the back surface 1b may be irradiated on the back surface 1b including a center diameter of 50 mm. The workpiece 1 reflects the light incident on the back surface 1b in the front direction. The light reflected by the workpiece 1 is incident on the beam splitter 52, and a part of the light is transmitted.

Then, the light transmitted through the beam splitter 52 is focused by the lens 56b disposed between the beam splitter 52 and the image capturing unit 44 on the image capturing unit 44. The light incident on the imaging unit 44 by the condensed light is finally condensed by a lens 56 c provided in the imaging unit 44 and reaches the light receiving element 54. The imaging unit 44 images the light reaching the light receiving element 54 to form a captured image.

If the inspection device 36c is used, the distortion of the captured image formed by the imaging unit 44 can be minimized, so that the uneven state of the back surface 1b of the workpiece 1 can be evaluated more accurately.

Furthermore, the central area of the processed surface including the center of the processed surface may be written in the captured image, and the periphery of the processed surface surrounding the central area may not be written in the captured image. region. Processing marks formed on the processed surface of the workpiece by grinding processing are easier to pass through the central region of the processed surface including the center of the processed surface, so it is possible to determine the quality of the workpiece by grasping the state of the unevenness formed on the central region. Bad or bad situation. For example, the central region is a circular region having a diameter of 50 mm.

In addition, the structures, methods, and the like related to the above embodiments can be implemented with appropriate changes without departing from the scope of the present invention.

1‧‧‧Workpiece

1a‧‧‧ surface

1b‧‧‧ back

3‧‧‧ divided scheduled line

5‧‧‧ components

7‧‧‧ protective tape

2‧‧‧ Grinding device

4‧‧‧ abutment

6‧‧‧ rotating table

8‧‧‧ chuck table

8a‧‧‧ keep face

10, 10a‧‧‧grinding unit

10b‧‧‧grinding unit

12, 12a‧‧‧ Pillar

14, 14a‧‧‧ spindle motor

16, 16a ‧ ‧ grinding wheel

16b‧‧‧ grinding wheel

18, 18a ‧ ‧ grinding grinding stone

18b‧‧‧ polishing pad

20, 20a‧‧‧ processing feed unit

22, 22a‧‧‧ Cassette Loading Platform

24, 24a‧‧‧ Cassette

26‧‧‧Workpiece transfer robot

28‧‧‧ positioning table

30‧‧‧ Workpiece moving mechanism (loading arm)

32‧‧‧ Workpiece removal mechanism (unloading arm)

34‧‧‧Rotary cleaning device

36, 36a, 36b, 36c ‧‧‧ Inspection device

38, 38a, 38b, 38c

40, 40a, 40b, 40c‧‧‧‧

42, 42a‧‧‧Screen

44‧‧‧ camera unit

46‧‧‧light

48a, 48b, 48c ‧‧‧ concave mirror

50‧‧‧ PC

52‧‧‧ Beamsplitter

54‧‧‧ light receiving element

56a, 56b, 56c‧‧‧ lens

FIG. 1 (A) is a perspective view schematically showing a workpiece, and FIG. 1 (B) is a perspective view schematically showing a workpiece to which a protective tape is stuck. FIG. 2 is a perspective view schematically showing a processing device including an inspection device. FIG. 3 (A) is a side view schematically showing a grinding process, and FIG. 3 (B) is a side view schematically showing a grinding process. FIG. 4 is a diagram schematically showing a configuration example of an inspection device. 5 (A) and 5 (B) are diagrams schematically showing a configuration example of an inspection device. FIG. 6 is a diagram schematically showing a configuration example of an inspection device.

Claims (10)

A method for inspecting a workpiece includes: a processing step for processing the workpiece with a grinding stone or a polishing pad; a projection step for irradiating light from a light source onto a processed surface of the workpiece, and the reflected surface of the processed surface The light reaches the screen, thereby projecting the projection image reflecting the state of the unevenness formed on the processed surface in the processing step onto the screen; the imaging step is to take an image of the projection image of the screen to form a camera An image; and a determining step of grasping the uneven state of the workpiece based on the captured image, and further determining whether the workpiece is good or bad. A method for inspecting a workpiece, comprising: a processing step for processing the workpiece with a grinding stone or a polishing pad; an imaging step for irradiating light from a light source onto a processed surface of the workpiece and reflecting the processed surface The light is imaged to form a captured image, and the captured image is written into an image reflecting the state of the unevenness formed on the processed surface in the processing step; and the determination step is based on the captured image. Grasp the uneven state of the workpiece, and then determine whether the workpiece is good or bad. The method for inspecting a workpiece according to item 1 or 2 of the scope of patent application, wherein the camera image is written in a central area of the processed surface including the center of the processed surface; in the camera image, The peripheral area of the processed surface surrounding the central area is not written. A workpiece inspection device includes: a holding table for holding the workpiece while a processed surface of the workpiece processed by a grinding stone or a polishing pad is exposed; a light source for irradiating light on the workpiece held by the holding table; The processed surface; the screen is illuminated by the light reflected by the processed surface, thereby reflecting a projection image reflecting the state of the unevenness formed by the processing on the processed surface of the workpiece; and a camera unit, The projection image of the screen is captured to form a captured image. A workpiece inspection device includes: a holding table for holding the workpiece while a processed surface of the workpiece processed by a grinding stone or a polishing pad is exposed; a light source for irradiating light on the workpiece held by the holding table; The processed surface; and an imaging unit that detects the light reflected from the processed surface to form a captured image. The inspection device for a workpiece according to item 4 or 5 of the scope of patent application, further comprising: a determination unit that grasps the uneven state of the workpiece based on the captured image, and further determines whether the workpiece is good or bad. The inspection device for a workpiece according to item 6 of the scope of patent application, wherein the determination unit is in a central region of the processed surface including the center of the processed surface, and an outer peripheral region of the processed surface surrounding the central region. When the continuous unevenness is detected, the workpiece is determined to be defective. The inspection device for a workpiece according to item 4 or 5 of the scope of patent application, wherein the camera image is written in a central area of the processed surface including the center of the processed surface, and the camera image is not A peripheral area of the processed surface surrounding the central area is written. The inspection device for a workpiece according to item 6 of the patent application scope, wherein the camera image is written in a central area of the processed surface including the center of the processed surface, and the camera image is not written A peripheral area of the processed surface surrounding the central area. A processing device includes: a chuck table that holds a workpiece; a processing unit that uses the grinding stone or the polishing pad to process the workpiece held by the chuck table; a cleaning unit that processes the workpiece that has been processed Cleaning the processed surface; and an inspection unit that inspects the unevenness of the processing marks formed on the processed surface of the workpiece being cleaned, wherein the inspection unit is any of the 4th to 9th in the scope of patent application An inspection device for a workpiece according to one item.