TWI741151B - Workpiece inspection method, work piece inspection device and processing device - Google Patents

Abstract

[Question] It is more appropriate and convenient to detect the grinding marks of the workpiece. [Solution] The present invention includes: a processing step, which is to process a workpiece with a grinding stone or a polishing pad; and a projection step, which irradiates light from a light source on the processed surface of the workpiece and is reflected by the processed surface The light reaches the screen, so that the projection image reflecting the state of the unevenness formed on the processed surface in the processing step is projected on the screen; the imaging step is to capture the projection image of the screen to form a camera Image; and the determination step, based on the camera image to grasp the uneven state of the workpiece, and then determine whether the workpiece is good or bad.

Description

Workpiece inspection method, work piece inspection device and processing device

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

Processing techniques such as grinding various flat workpieces made of materials such as silicon, SiC, and sapphire with a grinding stone or grinding with a polishing pad are known. The grinding grindstone 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 non-woven fabric or urethane pad is used together with abrasive grains to polish the polished surface of the workpiece.

In the grinding process using a grinding stone or the grinding process using a polishing pad, the grinding stone or the polishing pad is in contact with the workpiece to perform the processing. In this kind of processing, the abrasive particles dropped from the grinding stone, the grinding chips or agglomerated abrasive particles from the workpiece may enter between the grinding stone or the grinding pad and the workpiece. If the processing is continued, it will be Deep and long grinding marks (scratches) are formed on the workpiece.

If the workpiece formed by the grinding marks is divided to form each element wafer, the flexural strength of the element wafer will be reduced. Therefore, some people have proposed the following methods: taking a video of the workpiece during or after processing to detect the grinding marks, or irradiating the workpiece with laser light and then detecting the grinding marks according to the intensity of the reflected laser light. [Literature Technical Documents] [Patent Documents]

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

[Problem to be Solved by the Invention] However, no matter what method is implemented, the structure of the device capable of detecting the grinding marks is complicated. In addition, the high price of the device is a problem.

The present invention was completed in view of the problem of the upper opening, and its purpose is to provide a workpiece inspection method and workpiece that can more appropriately and appropriately detect the uneven state such as grinding marks (scratches) formed on the workpiece surface of the workpiece The inspection device and processing device. [Technical means to solve the problem]

According to a first aspect of the present invention, a method for inspecting a workpiece is provided, which is characterized by: a processing step, which is to process the workpiece with a grinding stone or a polishing pad; and a projection step, which is to irradiate light from a light source on the workpiece The processed surface, and the light reflected by the processed surface reaches the screen, thereby reflecting the projection image that reflects the state of the unevenness formed on the processed surface during the processing step on 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 according to the captured image, and then determine whether the workpiece is good or bad.

According to a second aspect of the present invention, a method for inspecting a workpiece is provided, which is characterized by having: a processing step, which is to process the workpiece with a grinding stone or a polishing pad; and an imaging step, which is to irradiate light from a light source on the workpiece The light reflected by the processed surface is captured to form a captured image, and the captured image is written to reflect the state of the unevenness formed on the processed surface during the processing step ; And the determination step, is based on the camera image to grasp the uneven state of the workpiece, and then determine whether the workpiece is good or bad.

According to a third aspect of the present invention, a method for inspecting a workpiece related to the first aspect or the second aspect of the present invention is provided. The central area of the processed surface, and in the captured image, the outer peripheral area of the processed surface surrounding the central area is not written.

According to a fourth aspect of the present invention, a device for inspecting a workpiece is provided, which is characterized by having: a holding table for holding the workpiece in a state where the workpiece surface of the workpiece processed by the grinding stone or 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 that the processed surface of the workpiece is reflected by the processed surface The projection image of the formed concavity and convexity state; and the imaging unit, which captures the projection image reflected on the screen to form a captured image.

According to a fifth aspect of the present invention, a device for inspecting a workpiece is provided, which is characterized by having: a holding table for holding the workpiece in a state where the workpiece surface of the workpiece processed by the grinding stone or 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 imaging unit detects the light reflected by the processed surface to form a captured image.

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

In the fourth aspect and the fifth aspect of the present invention, it is also possible that: in the captured image, write the center area of the processed surface including the center of the processed surface; in the captured image, no Write the outer peripheral area of the processed surface surrounding the central area.

One aspect of the present invention is also a processing device, which is characterized by having: a chuck table, which holds a workpiece; a processing unit, uses the grinding stone or the polishing pad to process the workpiece held by the chuck table; The cleaning unit is to clean the processed surface of the processed workpiece; and the inspection unit is to inspect the uneven state of the processing traces formed on the processed surface of the cleaned workpiece; wherein, the inspection unit, It is a work piece inspection device related to the present invention. [Efficacy of invention]

According to an aspect of the present invention, the inspection method, inspection device, and processing device can grasp the image formed by the processing on the processed surface of the workpiece based on the captured image captured by a simple configuration including a light source, a screen, or a concave mirror. Concave and convex conditions such as grinding marks (scratches). In the imaging of this captured image, light that is irradiated from a light source on the processed surface of the workpiece and reflected from the processed surface is used.

If unevenness is formed on the processed surface of the workpiece due to processing, an image that emphasizes the uneven state is written in a captured image formed by light irradiated on the processed surface. Therefore, it is easy to grasp the state of the unevenness formed on the surface to be processed, and it is easy to inspect the workpiece. When it is confirmed that there are irregularities on the processed surface of the workpiece that exceed the allowable degree, the workpiece can be judged as a defective product, and the processing can be stopped to confirm the state of the grinding stone or polishing pad.

Therefore, according to one aspect of the present invention, there is provided a workpiece inspection method, a workpiece inspection device, and a processing device that can more appropriately and easily detect the uneven state such as grinding marks (scratches) formed on the workpiece surface .

With reference to the drawings, an embodiment related to one aspect of the present invention will be described. 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, silicon, SiC (Silicon Carbide), or other semiconductor materials, or sapphire, glass, quartz and other materials that are made of a disc-shaped substrate.

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

Next, the protective tape attached to the surface 1a of the workpiece 1 will be described using FIG. 1(B). In Fig. 1(B), the protective tape 7 is schematically shown. The protective tape 7 has the function of protecting the components 5 formed on the surface 1a of the workpiece 1 and the like. The protective tape 7 protects the surface 1a of the workpiece 1 from impact caused by processing or conveying the back of the workpiece 1, and prevents damage to the component 5.

The protective tape 7 has a flexible film-like substrate and an adhesive layer (adhesive layer) formed on one surface of the substrate. For example, PO (polyolefin) is used as the base material. PET (polyethylene terephthalate), polyvinyl chloride, polystyrene, etc., which are more rigid than PO, can also be used. In addition, for the adhesive layer (adhesive layer), for example, silicone rubber, acrylic material, epoxy material, etc. are used.

Next, a description will be given of a processing device incorporating an inspection device for inspecting the work 1 on which unevenness is formed. 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 a chuck table 8 attached to a disk-shaped turntable 6, a grinding unit 10, and a grinding unit 10 a on a substantially rectangular parallelepiped base 4. A pillar 12 and a pillar 12a are erected at the rear of the base 4, and the pillar 12 and the pillar 12a are respectively provided with a grinding unit 10 and a grinding unit 10a.

The base 4 is provided with a disc-shaped rotating platform 6 that can rotate in a 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 workpiece loading and unloading area, the first grinding area, The second grinding area. In the first grinding area, for example, rough grinding is performed; in the second grinding area, for example, fine grinding is performed.

The chuck table 8 has a suction channel (not shown) with one end connected to a suction source (not shown), and the other end of the suction channel is connected with a holding surface 8a 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 sucks and holds the workpiece.

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

The front side part of the base 4 is higher than the part where the turntable 8 is provided, and the cassette mounting tables 22 and 22a are fixed to the front end of the base 4. A cassette 22 for storing the workpiece 1 before grinding is placed on the cassette placing table 22, and a cassette 24a for storing the workpiece 1 after grinding is placed on the cassette placing table 22a.

The workpiece conveying robot arm 26 is attached to the base 4 adjacent to the cassette mounting tables 22 and 22a. The front part of the base 4 is further equipped with a positioning table 28 with multiple positioning pins, a workpiece carrying mechanism (loading arm) 30, a workpiece carrying mechanism (unloading arm) 32, and a rotation for cleaning and rotating the ground workpiece. Cleaning device 34.

The grinding device 2 includes an inspection device 36 according to the present embodiment between the rotating 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 obliquely, a light source 40 for emitting light to the entire workpiece 1 held by the holding table 38 is arranged. As the light source 40, for example, an incandescent bulb or LED is used. However, there are no restrictions on the type or position of the light source 40. In addition, the light may be parallel light or non-parallel light. If the light is parallel light, for example, optical elements such as a concave mirror can be combined with the light source 40. In addition, a light source that has a small light-emitting area and is regarded as a point light source can also be used to obtain parallel or non-parallel light.

On the path (optical path) of the light reflected by the workpiece 1, a screen 42 is provided which is irradiated by the reflected light to form a projected image. The screen 42 is typically a flat screen, and is formed to be approximately the same size as the workpiece 1 or a size that can display the central area of the workpiece. The unevenness formed by the processing on the processed surface easily passes through the center area of the workpiece. Therefore, if a screen capable of projecting a diameter of about 50 mm near the center of the workpiece is used, it is easier to check the uneven state.

In this embodiment, the light source 40 is arranged obliquely above the holding table 38, and the screen 42 is arranged on the path of the light reflected by the workpiece 1. If the light that advances obliquely downward from the light source 40 is emitted to the workpiece 1, the light will be reflected by the exposed surface of the workpiece 1 (here, the back surface 11 b) and irradiate the screen 42. As a result, a projection image reflecting the state of the exposed surface of the workpiece 1 (that is, the back surface 1b) is formed on the screen 42.

At a position where the screen 42 can be seen, a camera unit (photographing means) 44 for taking a photograph of the projected image formed on the screen 42 to form a photographed image is arranged. The imaging unit 44 is a digital camera that combines imaging elements such as CCD or CMOS and optical elements such as lenses, and outputs a captured image (image) formed by capturing a projected image to the outside. Furthermore, as the imaging unit 44, any one of a digital still camera for forming a still image and a digital camera for forming an animation can also be used.

Here, the inclination angle of the screen 42 will be described with reference to FIG. 4. In FIG. 4, the relative 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 1b of the workpiece 1 is incident on the screen 42 perpendicularly, so that the screen 42 is tilted in this way.

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

The imaging unit 44 is connected to the judging unit (not shown), which is used to confirm the state of the unevenness formed by the processing on the processed surface (rear 1b) of the workpiece 1 from the captured image output by the imaging unit 44, and According to the uneven state, the quality of the workpiece 1 is judged.

Furthermore, the inspection device 36 may also have 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 condensed 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 that grinds a workpiece by a grinding unit equipped with a grinding grindstone, but may be a grinding device that grinds a workpiece by a grinding unit equipped with a polishing pad.

Next, the inspection method of the workpiece according to the present embodiment implemented 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 implemented.

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

First, as shown in FIG. 3(A), a case where the grinding unit 10 provided in the grinding device 2 performs grinding processing on the back surface 1b side of the workpiece 1 will be described. The work 1 is mounted on the holding surface 8a of the chuck table 8 with the surface 1a facing downwards through the protective tape 7. Next, the workpiece 1 is sucked and held on the chuck table 8 so that the back surface 1b side of the workpiece 1 is exposed upward. The rotating table 6 (refer to FIG. 2) of the grinding device 2 is rotated, and the chuck table 8 is positioned below the grinding unit 10.

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

Furthermore, 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. The grinding unit 10b is provided in the grinding device 2 to replace, for example, the grinding unit 10a of the grinding device 2 shown in FIG. 2. Furthermore, the polishing unit 10b may also be included in a polishing device that does not include a grinding unit.

The polishing unit 10b has 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 the grinding unit 10b is used for grinding processing, similar to the above-mentioned grinding processing, the workpiece 1 is placed on the holding surface 8a of the chuck table 8 with the protective tape 7 interposed in the state where the surface 1a of the workpiece 1 faces the chuck table 8. superior. Next, the workpiece 1 is sucked and held on the chuck table 8 so that the back surface 1b side of the workpiece 1 is exposed upward.

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

During the grinding process with the grinding grindstone 18 or the grinding process with the polishing pad 18b, the abrasive grains dropped from the grinding grindstone 18, the grinding chips or aggregated abrasive grains from the workpiece 1 may enter the grinding grindstone 18 or If processing continues between the polishing pad 18b and the workpiece 1, deep and long grinding marks (scratches) will be formed on the workpiece 1. If the workpiece 1 formed by the grinding marks is divided to form individual element wafers, the flexural strength of the element wafer will be reduced, and it will not function as a component and become a defective product.

Therefore, in the inspection method of the workpiece according to this embodiment, the projection step, the imaging step, and the determination step are then implemented to grasp the uneven state such as grinding marks (scratches) formed on the processed surface of the workpiece 1 to determine the workpiece Good or bad.

In the projection step, light is irradiated on 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 (refer to FIG. 2). In this process, the processed surface of the workpiece 1 is cleaned by the rotating cleaning device 34. With the surface 1a side of the workpiece 1 facing the holding table 38, the workpiece 1 is placed on the holding table 38 with the protective tape 7 interposed therebetween, so that the processed surface (back 1b) is exposed upward.

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

In addition, 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 (rear 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 on the processed surface due to processing. Here, when the angle between the light 46 reflected by the workpiece 1 and the back surface 1b is the same as the inclination angle of the screen 42 and the vertical plane of the processed surface of the workpiece 1, the distortion of the projected image becomes extremely low.

After that, the imaging step is carried out. This projected 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 should be adjusted appropriately. Next, the captured image formed by the imaging unit 44 is sent to a determination unit (not shown).

After the imaging step, a determination step is implemented: according to the captured image formed by the imaging unit 44, the uneven state of the workpiece is grasped, and then the quality of the workpiece is determined. 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 (the back surface 1b) of the workpiece 1.

The projected image is an image formed by the light 46 irradiated on the processed surface of the workpiece being reflected by the processed surface and irradiated on the screen 42. Here, the surface to be processed is substantially a mirror surface, and the light 46 is mirror-reflected on the surface to be processed. However, when the surface to be processed has minute irregularities formed, the light 46 is affected by the irregularities and partially diffuses or converges.

Therefore, the projected image will be an image with contrast between light and dark that reflects the state of the tiny irregularities formed on the surface to be processed. Moreover, this kind of light reflected by the mirror is projected on a screen, etc., and the formed image reflects the concavity and convexity of the mirror, and the contrast of light and dark is called the magic mirror image. Then, compared to the captured image formed by directly capturing the processed surface, the captured image formed by capturing the projection image projected on the screen 42 can be more effectively used to grasp the captured image formed on the processed surface. The state of unevenness. Therefore, the concave-convex state is emphasized by the magic mirror visualization.

Therefore, it is easier to grasp the uneven state of the workpiece based on the captured image written in the projection image. For example, when there is no unevenness 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 surface to be processed, the projection image written in the captured image will have a bright and dark pattern that emphasizes the state of the unevenness formed on the surface to be processed. In other words, the uneven state of the workpiece can be grasped from the captured image.

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

For example, the determination unit determines that the workpiece 1 is a defective product when continuous irregularities (processing traces) are detected in the center region of the workpiece 1 including the center of the processed surface and the outer peripheral region surrounding the center region. Here, the central area refers to, for example, a circular area about 1/3 to 1/4 of the radius of the workpiece from the center of the processed surface; the outer peripheral area refers to the central area of the processed surface Outside the area.

The continuous unevenness (processing trace) between the central area and the outer peripheral area is difficult to form under normal processing. Therefore, 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 The uneven workpiece 1 is judged as defective.

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

If the inspection method of the workpiece described above is implemented, it is possible to easily grasp the uneven state such as processing marks (scratches) formed on the processed surface of the workpiece 1 based on the captured image formed by the simple structure.

Furthermore, in the above embodiment, the light is directly irradiated on the workpiece 1 from the light source, but it is also possible to irradiate the light from the light source on the concave mirror, and allow the parallel light reflected by the concave mirror to irradiate the workpiece 1. In this case, use Figure 5 (A) to illustrate.

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 the inspection device 36a, the light emitted from the light source 40a is irradiated on the concave mirror 48a. The concave mirror 48a reflects 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 projected image, and sends the captured image to the personal computer 50. The personal computer 50 has a function as a judging unit to grasp the uneven state of the workpiece based on the captured image, and then judge whether the workpiece is good or bad.

In addition, in the above-mentioned embodiment, the light reflected by the workpiece 1 is irradiated on the screen to form a projected image, and the image pickup unit is caused to photograph the projected image to form a captured image. However, a concave mirror can also be provided to replace the screen, so that the light reflected by the workpiece 1 is irradiated on the concave mirror, and the light is condensed toward the imaging unit. In this case, use Figure 5 (B) to illustrate.

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

In the inspection device 36b, the light emitted from the light source 40b is irradiated on the concave mirror 48b. The concave mirror 48b reflects 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 allows the parallel light irradiated on the concave mirror 48c to be reflected toward the imaging unit 44 and focused. The imaging unit 44 detects the light reflected by the concave mirror 48c.

The imaging unit 44 sends the captured image obtained by imaging to the personal computer 50. The personal computer 50 has a function as a judging unit to grasp the uneven state of the workpiece based on the captured image, and then judge whether the workpiece is good or bad. Here, the captured image is not a projected image formed by irradiating the light reflected by the workpiece 1 on the screen, but the light is reflected by the concave mirror 48c and condensed on the imaging unit 44. Directly capture the image.

The light reflected by the workpiece 1 is condensed on the imaging unit 44, so the amount of light reaching the captured image increases, and the resulting captured image is clearer. Therefore, the uneven state of the processed surface of the workpiece 1 can be evaluated more accurately, and the personal computer 50 functioning as a judging unit can perform more detailed judgments.

In addition, the light is incident perpendicularly to the back surface 1b of the workpiece 1, and the reflected light is captured by the imaging unit 44 disposed on the front surface of the back surface 1b of the workpiece 1, thereby obtaining a captured image without distortion. The inspection device 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 spectroscope 52, and an imaging unit 44. The light emitted from the light source 40c becomes parallel light by the mirror 56a between the light source 40c and the beam splitter 52. If the parallel light is incident on the beam splitter 52 arranged on the front surface of the workpiece 1 held by the holding table 38c, a part of it will be reflected toward the workpiece 1.

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

Then, the light transmitted through the dichroic mirror 52 is condensed on the imaging unit 44 by the lens 56b arranged between the dichroic mirror 52 and the imaging unit 44. The condensed light incident on the imaging unit 44 is finally condensed by the lens 56 c included in the imaging unit 44 and reaches the light receiving element 54. The imaging unit 44 captures the light that reaches 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 unevenness of the back surface 1b of the workpiece 1 can be more accurately evaluated.

Furthermore, it may also be: the captured image is written with the central area of the processed surface including the center of the processed surface, and the captured image is not written with the outer periphery of the processed surface surrounding the central area area. Machining traces formed on the work surface of the workpiece by grinding processing can easily pass through the center area of the work surface including the center of the work surface, so the state of the unevenness formed on the center area can be grasped to determine the quality of the work. Bad or not. For example, the central area is a circular area with a diameter of 50 mm.

In addition, the structure, method, etc. related to the above-mentioned embodiment can be implemented with appropriate changes without departing from the scope of the object of the present invention.

1‧‧‧Workpiece 1a‧‧‧Surface 1b‧‧‧Back 3‧‧‧Preparation line 5‧‧‧Component 7‧‧‧Protective tape 2‧‧‧Grinding device 4‧‧‧Base 6‧‧‧Rotation Table 8‧‧‧Chuck table 8a‧‧‧Retaining surface 10, 10a‧‧‧ Grinding unit 10b‧‧‧ Grinding unit 12, 12a‧‧ Pillar 14, 14a‧‧‧ Spindle motor 16, 16a‧‧‧ Grinding Wheel 16b‧‧‧Grinding wheel 18,18a‧‧‧grinding stone 18b‧‧‧grinding pad 20,20a‧‧‧processing feed unit 22,22a‧‧‧cartridge placing table 24,24a‧‧‧cartridge 26‧‧‧Workpiece transfer robot 28‧‧‧Positioning table 30‧‧‧Workpiece carrying mechanism (loading arm) 32‧‧‧Workpiece carrying mechanism (unloading arm) 34‧‧‧Rotary cleaning device 36, 36a, 36b, 36c ‧‧‧Inspection device 38, 38a, 38b, 38c‧‧‧Holding table 40, 40a, 40b, 40c‧‧‧Light source 42, 42a‧‧‧Screen 44‧‧‧Camera unit 46‧‧‧Light 48a,48b, 48c‧‧‧Concave mirror 50‧‧‧PC 52‧‧‧Splitter 54‧‧‧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 pasted. Fig. 2 is a perspective view schematically showing a processing device including an inspection device. Fig. 3(A) is a side view schematically showing the grinding process, and Fig. 3(B) is a side view schematically showing the grinding process. Fig. 4 is a diagram schematically showing a configuration example of the inspection device. 5(A) and 5(B) are diagrams schematically showing examples of the structure of the inspection device. Fig. 6 is a diagram schematically showing a configuration example of the inspection device.

2‧‧‧ Grinding device

4‧‧‧Abutment

6‧‧‧Rotating table

8‧‧‧Chuck table

8a‧‧‧Keep the surface

10, 10a‧‧‧grinding unit

12, 12a‧‧‧pillar

14, 14a‧‧‧Spindle motor

16, 16a‧‧‧grinding wheel

18, 18a‧‧‧grinding stone

20, 20a‧‧‧Processing feed unit

22, 22a‧‧‧Cassette table

24, 24a‧‧‧Cassette

26‧‧‧Workpiece transport robot arm

28‧‧‧Positioning table

30‧‧‧Workpiece loading mechanism (loading arm)

32‧‧‧Workpiece removal mechanism (unloading arm)

34‧‧‧Rotary cleaning device

36‧‧‧Checking device

38‧‧‧Holding Taiwan

40‧‧‧Light source

42‧‧‧Screen

44‧‧‧Camera unit

Claims (7)

A method for inspecting a workpiece includes: a processing step, which is to process the workpiece with a grinding stone or a polishing pad; The light reaches the screen, thereby projecting a projection image reflecting the state of the unevenness formed on the processed surface during the processing step on the screen; the imaging step is to capture the projection image of the screen to form A photographed image; and a determination step of grasping the uneven state of the workpiece according to the photographed image, and then determining whether the workpiece is good or bad, the photographed image is written including the center of the processed surface The central area of the processed surface; in the captured image, the outer peripheral area of the processed surface surrounding the central area is not written. A method for inspecting a workpiece, comprising: a processing step of processing the workpiece with a grinding stone or a polishing pad; and an imaging step of irradiating light from a light source on the processed surface of the workpiece and reflecting the processed surface The light is photographed, thereby forming a photographed image, and the photographed image is written into an image reflecting the state of the unevenness formed on the surface to be processed in the processing step; and the determination step is based on the photographed image To grasp the uneven state of the workpiece, and then determine whether the workpiece is good or bad, the captured image is written in the center area of the processed surface including the center of the processed surface; The outer peripheral area of the processed surface surrounding the central area is not written. An inspection device for workpieces, including: The holding table is to hold the workpiece under the state of exposing the machined surface of the workpiece processed by the grinding stone or polishing pad; the light source irradiates light on the machined surface of the workpiece held by the holding table; the screen is Irradiated 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, which is reflected on the screen The projected image is captured to form a captured image. The captured image is written in the center area of the processed surface including the center of the processed surface. The captured image is not written in the center area surrounding the center area. The peripheral area of the machined surface. A device for inspecting a workpiece, comprising: a holding table for holding the workpiece in a state where the workpiece surface to be processed by a grinding stone or a polishing pad is exposed; a light source that irradiates light on the workpiece held by the holding table The processed surface; and the imaging unit, which detects the light reflected by the processed surface to form a captured image, and the captured image is written in the center area of the processed surface including the center of the processed surface In the captured image, the outer peripheral area of the processed surface surrounding the central area is not written. For example, the inspection device of the workpiece described in item 3 or 4 of the scope of patent application is further equipped with: a judging unit, which grasps the uneven state of the workpiece according to the camera image, and then judges the quality of the workpiece. The inspection device of the workpiece according to the fifth item of the scope of patent application, wherein the determining unit is located in the central area of the processed surface including the center of the processed surface and the outer peripheral area of the processed surface surrounding the central area When the continuous unevenness is detected, the workpiece is judged to be a defective product. A processing device is provided with: a chuck table for holding a workpiece; a processing unit for processing the workpiece held by the chuck table with the grinding stone or the polishing pad; and a cleaning unit for processing the workpiece The processed surface is cleaned; and the inspection unit is to inspect the uneven state of the processing traces formed on the processed surface of the cleaned workpiece, wherein the inspection unit is any of items 3 to 6 in the scope of patent application The inspection device of the workpiece mentioned in one item.

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