An optical path defining element and a detection method, device using the same

Abstract

The application discloses a light path limiting element, which comprises a mounting base, a first reflecting surface and a second reflecting surface. The mounting base is provided with an obliquely arranged mounting surface and an elongated hole. The elongated hole is arranged through the mounting base from the mounting surface and divides the mounting surface into a first mounting surface and a second mounting surface. The first mounting surface and the second mounting surface are respectively used for mounting the first reflecting surface and the second reflecting surface. The first reflecting surface and the second reflecting surface are used for reflecting light. The elongated hole is used for transmitting light. The application can effectively solve the problem that the existing square prism affects the imaging effect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of silicon wafer sorting, and particularly relates to a light path limiting element and a detection method and device using the element. BACKGROUND

[0002] Before the silicon wafer is made into a battery wafer, a series of defect detection needs to be performed on the silicon wafer, one of which is to detect the side edge of the silicon wafer.

[0003] The existing detection method mainly uses a square prism to reflect or transmit the light source. The light transmitted through the square prism will be partially reflected again by the bottom of the square prism, resulting in an excessively bright background in the image, which affects the imaging effect and further interferes with the side edge detection. SUMMARY

[0004] In view of the problem that the square prism used in the current side edge detection affects the imaging effect, the present application provides a light path limiting element and a detection method and device using the element.

[0005] In a first aspect, the present application provides a light path limiting element, which comprises a mounting seat, a first reflecting surface and a second reflecting surface. The mounting seat has an obliquely arranged mounting surface and a long and narrow hole. The long and narrow hole penetrates the mounting seat from the mounting surface and divides the mounting surface into a first mounting surface and a second mounting surface. The first mounting surface and the second mounting surface are used to mount the first reflecting surface and the second reflecting surface, respectively. The first reflecting surface and the second reflecting surface are used to reflect light, and the long and narrow hole is used to transmit light.

[0006] The light path limiting element of the present application not only can reflect light, but also has a long and narrow hole through which light can pass. Compared with the traditional square prism, if the light is to pass through the light path limiting element, it only needs to pass through the long and narrow hole, and does not need to pass through the diorite film of the square prism, so that the reflection and transmission of light on the light path limiting element can be realized. Therefore, the phenomenon of reflection of light by the bottom of the square prism itself can be completely avoided, and the problem of influence of the existing square prism on the imaging effect can be effectively solved.

[0007] Optionally, the width of the long and narrow hole is 0.8mm-2mm.

[0008] The width of the long and narrow hole is selected to be 0.8mm-2mm. When the light path limiting element of the present application is used to detect the side edge of the silicon wafer, the cooperation relationship between the light source, the camera and the silicon wafer to be detected can be better balanced, and thus the imaging effect of the side edge of the silicon wafer to be detected can be improved.

[0009] Optionally, the included angle between the obliquely arranged mounting surface and the horizontal plane is α, and 35°≤α≤55°.

[0010] The included angle between the installation surface and the horizontal plane is set to 35-55 degrees, which is beneficial to the installation of the light-reflecting surface and the reflection of light from the light-reflecting surface to the side edge of the silicon wafer to be detected.

[0011] Optionally, the included angle between the first light-reflecting surface and the second light-reflecting surface is β, 150°≤β≤180°.

[0012] The included angle between the first light-reflecting surface and the second light-reflecting surface is set to 150-180 degrees, so that the first light-reflecting surface and the second light-reflecting surface are arranged at an angle, the light reflected by the first light-reflecting surface and the light reflected by the second light-reflecting surface intersect at the same region, which is approximately the position of the side edge of the silicon wafer corresponding to the long hole, so that the light reflected by the silicon wafer and passing through the long hole is stronger, thereby the camera can take a better photo, and the detection accuracy of the side edge is improved.

[0013] Optionally, the end of the first installation surface away from the long hole is higher than the end of the first installation surface close to the long hole, the end of the second installation surface away from the long hole is higher than the end of the second installation surface close to the long hole, and the included angle between the first installation surface and the second installation surface is consistent with the angle β.

[0014] The included angle between the first installation surface and the second installation surface is designed to be consistent with the angle β, which is more beneficial to fixing the first light-reflecting surface and the second light-reflecting surface on the installation surface.

[0015] Optionally, the first light-reflecting surface and the second light-reflecting surface are respectively angle-adjustably installed on the first installation surface and the second installation surface.

[0016] The first light-reflecting surface is angle-adjustably installed on the first installation surface, and the second light-reflecting surface is angle-adjustably installed on the second installation surface, so that the included angle between the first light-reflecting surface and the second light-reflecting surface can be adaptively adjusted according to different detection environments, and the applicability of the light path limiting element is improved.

[0017] Optionally, the first light-reflecting surface and the second light-reflecting surface are mirrors or light-reflecting films.

[0018] The first light-reflecting surface and the second light-reflecting surface can be either mirrors or light-reflecting films, which are convenient to fix and controllable in cost.

[0019] Optionally, the inner cavity of the light path limiting element is blackened, and the inner cavity includes the inner wall of the long hole and / or the back surface of the first light-reflecting surface and the second light-reflecting surface.

[0020] The inner cavity of the light path limiting element is blackened, so that part of the light entering the inner cavity can be absorbed, avoiding unnecessary reflection and refraction of the light in the inner cavity and affecting the imaging effect.

[0021] In a second aspect, the present application provides a method for detecting a side edge of a silicon wafer, comprising: reflecting light onto the side edge of the silicon wafer by a light path limiting element, and reflecting the light reflected by the side edge of the silicon wafer to a detection camera through the light path limiting element.

[0022] The light path limiting element of the present application can be used to take a picture of the side edge of the silicon wafer, which can avoid the problem of too bright background interfering with the detection when taking a picture of the side edge of the silicon wafer, and thus improve the final imaging effect of the detection camera.

[0023] Optionally, reflecting the light onto the side edge of the silicon wafer by the light path limiting element comprises:

[0024] Reflecting part of the light by the first reflective surface and / or reflecting part of the light by the second reflective surface onto the side edge of the silicon wafer.

[0025] According to the specific situation of the detection of the side edge of the silicon wafer, the first reflective surface can be used to reflect part of the light onto the side edge of the silicon wafer, or the second reflective surface can be used to reflect part of the light onto the side edge of the silicon wafer, or both the first reflective surface and the second reflective surface can be used to reflect part of the light onto the side edge of the silicon wafer. When only one reflective surface is needed, the use of the reflective surface can be saved. When both the first reflective surface and the second reflective surface are used, the imaging effect can be improved, and the method can be suitable for silicon wafers of different qualities.

[0026] Optionally, reflecting the light onto the side edge of the silicon wafer by the light path limiting element comprises:

[0027] Reflecting the overlapping part of the light reflected by the first reflective surface and the light reflected by the second reflective surface onto the side edge of the silicon wafer.

[0028] Reflecting the overlapping part of the light reflected by the first reflective surface and the light reflected by the second reflective surface onto the side edge of the silicon wafer, i.e. the side edge of the silicon wafer can simultaneously receive the light reflected by the first reflective surface and the second reflective surface, so that the side edge of the silicon wafer can receive sufficient light and reflect it back to the detection camera, and the imaging effect is improved.

[0029] Optionally, reflecting the light reflected by the side edge of the silicon wafer to the detection camera through the light path limiting element comprises:

[0030] Reflecting the light reflected by the side edge of the silicon wafer to the detection camera through the long and narrow hole.

[0031] Through the cooperation of the long and narrow hole, the light reflected by the side edge of the silicon wafer can reach the detection camera without obstruction.

[0032] In a third aspect, the present application provides a silicon wafer detection device, comprising a conveying unit, an illumination unit, the light path limiting element according to any one of the preceding embodiments, an image acquisition unit, and an analysis unit. The conveying unit is configured to convey a silicon wafer to be detected to a photographing area and convey the photographed silicon wafer to a subsequent area. The illumination unit is configured to provide illumination to the silicon wafer to be detected. The light path limiting element is configured to reflect the light emitted by the illumination unit to the side edge of the silicon wafer to be detected and provide a channel for the light reflected by the side edge of the silicon wafer to be detected to enter the image acquisition unit. The image acquisition unit is configured to acquire a side edge image of the silicon wafer to be detected. The analysis unit is configured to analyze the side edge image.

[0033] The silicon wafer detection device of the present application adopts the light path limiting element of the present application, which can effectively solve the problem of the influence of the existing square prism on the imaging effect. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 An embodiment of the light path limiting element;

[0035] Figure 2 An optical path schematic diagram of the side edge of the silicon wafer when the light path limiting element of the present application is used; Figure 1

[0036] Figure 3 A schematic diagram of the first reflective surface and the second reflective surface hidden; Figure 1

[0037] Figure 4 Another embodiment of the light path limiting element;

[0038] Figure 5 A top view simplified diagram between the first reflective surface and the second reflective surface in the light path limiting element of the present application; Figure 3

[0039] An optical path schematic diagram of the light path limiting element of the present application; Figure 6 Figure 1 An optical path schematic diagram of the light path limiting element of the present application;

[0040] Figure 7 Figure 4 An optical path schematic diagram of the light path limiting element of the present application;

[0041] Figure 8 An embodiment of the silicon wafer detection device;

[0042] Figure 9 A silicon wafer side edge image photographed when the side edge detection is performed using the square prism in the prior art;

[0043] Figure 10A A silicon wafer side edge image photographed when the side edge detection is performed using the light path limiting element of the present application with a β angle of 180°;

[0044] Figure 10B ​​​​A silicon wafer side edge image photographed when a side edge detection is performed using the optical path limiting element of the present application with a β angle of 150°;

[0045] Figure 10C A silicon wafer side edge image photographed when a side edge detection is performed using the optical path limiting element of the present application with a β angle of 145°;

[0046] Figure 10D A silicon wafer side edge image photographed when a side edge detection is performed using the optical path limiting element of the present application with a β angle of 140°. DETAILED DESCRIPTION

[0047] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. The described embodiments are some embodiments of the present application, but not all the embodiments. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application.

[0048] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0049] In view of the problem that the square prism used in the current side edge detection affects the imaging effect, the present application provides an optical path limiting element and a detection method and device using the same.

[0050] As shown in Figure 1 The present application provides an optical path limiting element, which comprises a mounting seat 1, a first reflecting surface 2 and a second reflecting surface 3. The mounting seat 1 has an obliquely arranged mounting surface and a long hole 4. The long hole 4 is arranged through the mounting seat 1 from the mounting surface and divides the mounting surface into a first mounting surface 5 and a second mounting surface 6. The first mounting surface 5 and the second mounting surface 6 are respectively used for mounting the first reflecting surface 2 and the second reflecting surface 3. The first reflecting surface 2 and the second reflecting surface 3 are used for reflecting light. The long hole 4 is used for transmitting light.

[0051] The working principle of the optical path limiting element of the present application applied to the silicon wafer side edge detection will be described in detail below: Figure 2 The working principle of the optical path limiting element of the present application applied to the silicon wafer side edge detection will be described in detail below:

[0052] Figure 2 ​For example, when the second reflective surface 3 in the above embodiment is used as an example, after the external light source is used to hit the second reflective surface 3, the second reflective surface 3 will reflect the light source to the side edge 110 of the silicon wafer. Since the side edge of the silicon wafer itself has the ability to reflect light, the light incident on the side edge 110 of the silicon wafer will be reflected on the side edge 110 of the silicon wafer and then be reflected out of the side edge 110 of the silicon wafer. Part of the light reflected out of the side edge 110 of the silicon wafer will pass through the long and narrow hole 4 in the light path limiting element and reach the detection camera, thereby achieving the shooting of the side edge of the silicon wafer.

[0053] Figures 10A-10B For the silicon wafer side edge picture taken by the light path limiting element of the present application, Figure 9 For the silicon wafer side edge picture taken by the square prism, it can be clearly seen that after the light path limiting element of the present application is used, the picture taken does not have the problem of Figure 9 over-bright background.

[0054] When detecting the side edge 110 of the silicon wafer, the line-scan camera is preferentially selected to achieve the shooting of the side edge 110 of the silicon wafer during the continuous movement of the silicon wafer, which can greatly improve the detection efficiency of the side edge of the silicon wafer. The long and narrow hole in the light path limiting element of the present application can also better match the line-scan camera to prevent the hole from being too large and the reflected light from being too chaotic, thereby affecting the imaging effect of the line-scan camera.

[0055] The reflection principle of the first reflective surface 2 is the same as that of the second reflective surface 3 described above, which will not be described here again.

[0056] Although the above principle is introduced in combination with the detection of the side edge of the silicon wafer, the light path limiting element of the present application is not limited to the detection of the silicon wafer, but is also applicable to other sheet-shaped objects such as semiconductor wafers and battery sheets.

[0057] The light path limiting element of the present application not only can reflect light, but also has a long and narrow hole 4 through which light can pass. Compared with the traditional square prism, if the light is to pass through the light path limiting element, it only needs to pass through the long and narrow hole 4, and does not need to pass through the transparent and reflective film of the square prism, thereby realizing the reflection and transmission of light on the light path limiting element. Therefore, the phenomenon of the bottom of the square prism reflecting light can be completely avoided, and the problem of affecting the imaging effect of the existing square prism can be effectively solved.

[0058] When the width of the long and narrow hole 4 is 0.8mm-2mm, the cooperation relationship between the light source, the camera and the silicon wafer to be detected can be better balanced, thereby improving the imaging effect of the side edge of the silicon wafer to be detected.

[0059] It should be noted that the width of the long and narrow hole 4 on the light source limiting element can be the width confirmed during the processing of the mounting seat. This method is suitable for batch processing and is also convenient to install. Alternatively, Figure 3As shown, when the mounting seat is processed, a hole with a relatively wide width is first opened, and then when the first reflective surface 2 and the second reflective surface 3 are installed, the installation distance between the reflective surfaces is used to appropriately cover the relatively wide hole, and then a long and narrow hole 4 with a width required by the light path limiting element of the application is formed. This kind of mode is more suitable for different detection occasions, and the width of the long and narrow hole can be flexibly adjusted based on the use purpose.

[0060] As shown in the figure, the mounting seat 1 has an installation surface arranged obliquely, and in an optional embodiment, the included angle between the installation surface and the horizontal plane is 35°≤α≤55°. Figure 3

[0061] The included angle between the installation surface and the horizontal plane is α, and α can be 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°, 44°, 45°, 46°, 47°, 48°, 49°, 50°, 51°, 52°, 53°, 54°, 55° in the above range, which is more helpful to improve the imaging effect and reduce the debugging difficulty.

[0062] Setting the included angle between the installation surface and the horizontal plane to be 35°-55° is beneficial to the installation of the reflective surface, and this angle is more beneficial to reflecting the light from the reflective surface to the side edge of the silicon wafer to be detected.

[0063] For the detected target with strong light reflection capability, as shown in the figure, the first reflective surface 2 and the second reflective surface 3 can be directly tiled and fixed on the first installation surface 5 and the second installation surface 6, and the first reflective surface 2 and the second reflective surface 3 are installed as shown in the figure. Figure 3 Figure 1

[0064] As shown in the figure, the first reflective surface 2 and the second reflective surface 3 reflect the light to the side edge 110 of the silicon wafer, and since the side edge 110 of the silicon wafer has strong light reflection capability, the light reflected to the side edge 110 of the silicon wafer will be reflected out by the side edge 110 of the silicon wafer, and the light reflected out by the side edge 110 of the silicon wafer is shown as a dashed area in the figure, and the light that can pass through the long and narrow hole 4 can completely meet the imaging requirements of the detection camera. Figure 6 Figure 6 When the object with weak self reflection capability is detected, the light path limiting element of the application is used for light path control, which may cause the measured object to only reflect a small part of the light back to the long and narrow hole, thereby affecting the imaging effect. In order to solve this problem and make the light path limiting element of the application have better applicability, as shown in the figure, the included angle between the first reflective surface 2 and the second reflective surface 3 is β, and 150°≤β≤180°.

[0065] Figure 4 5 ​​​​​​​

[0066] As shown in Figure 10A , the side edge image of the silicon wafer taken by the light path limiting element when the side edge detection is performed at the β angle of 180° of the present application; it can be seen that, on the one hand, there is no problem of too bright background, and on the other hand, the imaging of the side edge of the silicon wafer is also relatively clear.

[0067] As shown in Figure 10B , the side edge image of the silicon wafer taken by the light path limiting element when the side edge detection is performed at the β angle of 170° of the present application; it can be seen that, on the one hand, there is no problem of too bright background, and on the other hand, the imaging of the side edge of the silicon wafer is also relatively clear.

[0068] As shown in Figure 10C , the side edge image of the silicon wafer taken by the light path limiting element when the side edge detection is performed at the β angle of 150° of the present application; it can be seen that, at this time, although there is no problem of too bright background, the imaging of the side edge of the silicon wafer starts to exist slight scratches (as shown in the enlarged view) which will not affect the image analysis.

[0069] As shown in Figure 10D , the side edge image of the silicon wafer taken by the light path limiting element when the side edge detection is performed at the β angle of 140° of the present application; it can be seen that, at this time, although there is no problem of too bright background, the imaging of the side edge of the silicon wafer exists relatively obvious scratches (as shown in the enlarged view), which will seriously affect the accurate analysis of the image due to the influence of the scratches.

[0070] Therefore, the angle between the first reflective surface 2 and the second reflective surface 3 is set to be between 150° and 180°, and the first reflective surface 2 and the second reflective surface 3 are arranged at an angle, so that the light reflected by the first reflective surface 2 to the side edge of the silicon wafer to be detected and the light reflected by the second reflective surface 3 to the side edge of the silicon wafer to be detected intersect at the same region 9, which is approximately the position of the side edge of the silicon wafer corresponding to the long hole 4, so that the light reflected by the side edge of the silicon wafer and passing through the long hole 4 is stronger, thereby making the camera take a better photo, and thus improving the detection accuracy of the side edge.

[0071] When the first reflective surface 2 and the second reflective surface 3 are at an angle β, in order to facilitate the installation of the first reflective surface 2 and the second reflective surface 3, the first mounting surface 5 and the second mounting surface 6 can be specially designed.

[0072] Specifically, as shown in Figure 4 , the end of the first mounting surface 5 away from the long hole 4 is higher than the end of the first mounting surface 5 close to the long hole 4, the end of the second mounting surface 6 away from the long hole 4 is higher than the end of the second mounting surface 6 close to the long hole 4, and the angle between the first mounting surface 5 and the second mounting surface 6 is consistent with the angle of β.

[0073] When the first reflective surface 2 and the second reflective surface 3 form an angle β, in order to make the first reflective surface 2 and the second reflective surface 3 have more selectable and adjustable angles, the first reflective surface 2 and the second reflective surface 3 are respectively angle-adjustably installed on the first mounting surface 5 and the second mounting surface 6.

[0074] Specifically, the first reflective surface 2 and the second reflective surface 3 are respectively fixedly installed on two rotating shafts, and the two rotating shafts are respectively rotatably arranged on the mounting seat, and the angle adjustment between the reflective surfaces can be realized by rotating the rotating shafts. Of course, in order to make the angle adjustment more accurate, a scale can also be arranged on the mounting seat.

[0075] Further, in order to realize the synchronous angle adjustment between the first reflective surface 2 and the second reflective surface 3, the same specification pinion gears that can mesh with each other can be arranged at the ends of the two rotating shafts.

[0076] The first reflective surface 2 is angle-adjustably installed on the first mounting surface 5, and the second reflective surface 3 is angle-adjustably installed on the second mounting surface 6, so that the angle between the first reflective surface 2 and the second reflective surface 3 can be adaptively adjusted according to different detection environments, and the applicability of the light path limiting element is improved.

[0077] Optionally, the first reflective surface 2 and the second reflective surface 3 are mirrors or reflective films.

[0078] The first reflective surface 2 and the second reflective surface 3 can be selected as mirrors or reflective films to reflect light, which is convenient to fix and controllable in cost.

[0079] Optionally, the inner cavity of the light path limiting element is blackened. The inner cavity in the present application can be the inner wall of the long and narrow hole 4, the back of the first reflective surface 2 and the second reflective surface 3, and the inner wall of the long and narrow hole 4 and the back of the first reflective surface 2 and the second reflective surface 3. Three different cases are selected according to different process requirements.

[0080] The inner wall of the long and narrow hole mainly refers to all inner surface positions of the long and narrow hole in the mounting seat.

[0081] Specifically, the blackening treatment can be a black layer or black light-absorbing cotton that can make the inner cavity have light-absorbing effect.

[0082] By blackening the inner cavity of the light path limiting element, part of the light entering the inner cavity can be absorbed, avoiding unnecessary reflection and refraction of light in the inner cavity and affecting the imaging effect.

[0083] In a second aspect, the present application provides a silicon wafer side edge detection method, which comprises: Figure 2As shown, the light is reflected by the light path limiting element to the side edge of the silicon wafer, and the light is reflected by the side edge of the silicon wafer and passes through the light path limiting element to the detection camera.

[0084] The light path limiting element of the present application is used to take a picture of the side edge of the silicon wafer, which can avoid the problem of too bright background interfering with detection when taking a picture of the side edge of the silicon wafer, and thus improve the final imaging effect of the detection camera.

[0085] Optionally, reflecting the light by the light path limiting element to the side edge of the silicon wafer includes:

[0086] Only part of the light is reflected by the first reflective surface 2 to the side edge of the silicon wafer.

[0087] Alternatively,

[0088] Only part of the light is reflected by the second reflective surface 3 to the side edge of the silicon wafer.

[0089] Alternatively,

[0090] Part of the light is reflected by the first reflective surface 2 and the second reflective surface 3 to the side edge of the silicon wafer.

[0091] It should be noted that the above three ways of reflecting light by the light path limiting element to the side edge of the silicon wafer can be applied to the case where the angle β between the first reflective surface 2 and the second reflective surface 3 is any value in the range of 150°, 150°-180°, and 180°.

[0092] According to the specific situation of the side edge detection of the silicon wafer, the first reflective surface 2 can be used alone to reflect part of the light to the side edge of the silicon wafer, or the second reflective surface 3 can be used alone to reflect part of the light to the side edge of the silicon wafer, or the first reflective surface 2 and the second reflective surface 3 can be used together to reflect part of the light to the side edge of the silicon wafer. When only one reflective surface is needed, the use of the reflective surface can be saved, and when two reflective surfaces are used at the same time, the imaging effect can be improved, which is suitable for silicon wafers of different qualities.

[0093] Optionally, reflecting the light by the light path limiting element to the side edge of the silicon wafer includes:

[0094] As shown in Figure 7 the first reflective surface 2 reflects part of the light, and the second reflective surface 3 reflects part of the light, and the overlapping part 9 of the light reflected by the first reflective surface 2 and the second reflective surface 3 is reflected to the side edge of the silicon wafer.

[0095] The overlapping part of the light reflected by the first reflective surface 2 and the second reflective surface 3 is reflected to the side edge of the silicon wafer, that is, the side edge of the silicon wafer can simultaneously receive the light reflected by the first reflective surface 2 and the second reflective surface 3, so that the side edge of the silicon wafer can receive sufficient light and reflect it back to the detection camera, thereby improving the imaging effect.

[0096] Optionally, light is reflected by the sides of the silicon wafer and passes through the optical path defining element to reach the detection camera, including:

[0097] Light is reflected by the side of the silicon wafer and passes through the narrow aperture 4 to reach the detection camera.

[0098] With the help of the narrow aperture 4, the light reflected from the side of the silicon wafer can reach the inspection camera without obstruction.

[0099] Thirdly, such as Figure 8 As shown, this application proposes a silicon wafer inspection device, including a conveying unit, an illumination unit 7, an optical path limiting element, an image acquisition unit 8, and an analysis unit. The conveying unit is used to convey the silicon wafer to be inspected to the imaging area and to convey the silicon wafer that has been photographed to the subsequent processing area. The illumination unit 7 is used to provide illumination to the silicon wafer to be inspected. The optical path limiting element is used to reflect the light emitted by the illumination unit to the side of the silicon wafer to be inspected and to provide a channel for the light reflected by the side of the silicon wafer to enter the image acquisition unit 8. The image acquisition unit 8 is used to acquire the side image of the silicon wafer to be inspected. The analysis unit is used to analyze the side image.

[0100] The silicon wafer inspection device of this application uses the optical path limiting element of this application, which can effectively solve the problem of existing square prisms affecting the imaging effect and improve the effect of silicon wafer side inspection.

[0101] The foregoing illustrative description of the invention and its embodiments is not restrictive, and the accompanying drawings are only one embodiment of the invention; the actual structure is not limited to this. Therefore, if a person skilled in the art, inspired by this description, designs a similar structure and embodiment without departing from the spirit of the invention, such design should fall within the scope of protection of this patent.

Claims

1. An optical path defining element, characterized in that The light path limiting element is applied to side edge detection of a silicon wafer, and comprises a mounting base, a first reflecting surface and a second reflecting surface. The mounting base has an obliquely arranged mounting surface and a long hole penetrating through the mounting base from the mounting surface to divide the mounting surface into a first mounting surface and a second mounting surface, and the first mounting surface and the second mounting surface are respectively used for mounting the first reflecting surface and the second reflecting surface. The first reflecting surface and the second reflecting surface are used for reflecting light, and the long hole is used for transmitting light. The first reflecting surface and the second reflecting surface are respectively angle-adjustably mounted on the first mounting surface and the second mounting surface.

2. The optical path defining element according to claim 1, characterized in that The width of the long hole is 0.8-2 mm.

3. The optical path defining element according to claim 1, characterized in that The included angle of the obliquely arranged mounting surface relative to a horizontal plane is α, and 35°≤α≤55°.

4. The optical path defining element according to claim 1, characterized in that The included angle between the first reflecting surface and the second reflecting surface is β, and 150°≤β≤180°.

5. The optical path defining element according to claim 4, characterized in that The end of the first mounting surface away from the long hole is higher than the end of the first mounting surface close to the long hole, the end of the second mounting surface away from the long hole is higher than the end of the second mounting surface close to the long hole, and the included angle between the first mounting surface and the second mounting surface is consistent with the angle of β.

6. The optical path defining element according to claim 1, characterized in that The first reflecting surface and the second reflecting surface are mirrors or reflecting films.

7. The optical path defining element according to claim 1, characterized in that The inner cavity of the light path limiting element is blackened, and the inner cavity comprises the inner wall of the long hole and / or the back surface of the first reflecting surface and the second reflecting surface.

8. A method of detecting the side edge of a silicon wafer, characterized by, The silicon wafer side edge detection method comprises the following steps: illuminating light on the light path limiting element according to any one of claims 1-7, reflecting the light on the side edge of a silicon wafer by the light path limiting element, and reflecting the light reflected by the side edge of the silicon wafer through the light path limiting element to a detection camera.

9. The method of claim 8, wherein the step of detecting the side edge of the silicon wafer is performed by a method comprising: detecting the side edge of the silicon wafer by using a light barrier. The light is reflected on the side edge of the silicon wafer by the light path limiting element, which comprises the following steps: Part of the light is reflected on the side edge of the silicon wafer by the first reflecting surface and / or part of the light is reflected on the side edge of the silicon wafer by the second reflecting surface.

10. The silicon wafer side edge detection method according to claim 8, characterized in that, The light is reflected on the side edge of the silicon wafer by the light path limiting element, which comprises the following steps: The overlapping part of the light reflected by the first reflecting surface and the light reflected by the second reflecting surface is reflected on the side edge of the silicon wafer.

11. The method of claim 8, wherein the step of detecting the side edge of the silicon wafer comprises the steps of: detecting the side edge of the silicon wafer by using a light barrier. The light is reflected on the side edge of the silicon wafer by the light path limiting element, which comprises the following steps: The light is reflected on the side edge of the silicon wafer by the light path limiting element, which comprises the following steps:

12. A silicon wafer inspection apparatus, characterized by comprising: The silicon wafer detection device comprises a conveying unit, a light unit, a light path limiting element according to any one of claims 1-7, an image acquisition unit and an analysis unit. The conveying unit is used for conveying a silicon wafer to be detected to a shooting area and conveying a silicon wafer that has been shot to a subsequent area. The light unit is used for providing light to the silicon wafer to be detected. The light path limiting element is used for reflecting the light emitted by the light unit to the side edge of the silicon wafer to be detected, and providing a channel for the light reflected by the side edge of the silicon wafer to be detected to enter the image acquisition unit. The image acquisition unit is used for acquiring the side edge image of the silicon wafer to be detected. The analysis unit is used for analyzing the side edge image.

Images