Offset information calculation method

Abstract

This application relates to the field of semiconductor manufacturing and discloses a method for calculating offset information. The method includes: acquiring a first image to be processed and at least one second image to be processed, captured by a vision component between two relatively placed first and second wafers; processing the first image to be processed to obtain first distance information and an angular offset; processing the second image to be processed to obtain second distance information; fitting and calculating the first and second distance information to obtain a first lateral offset and a second lateral offset of the second wafer relative to the first wafer, and using the first lateral offset, the second lateral offset, and the angular offset as offset information. The offset information calculation method according to the embodiments of this application improves the efficiency of acquiring offset information between two wafers.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, and in particular to a method for calculating offset information. Background Technology

[0002] Before bonding two wafers, they need to be aligned. In related technologies, the wafer alignment device acquires edge images of multiple locations on both wafers, and then relies on processing these multiple images to control the alignment of the wafers. However, this image processing is cumbersome, resulting in low efficiency in acquiring offset information between the two wafers. Summary of the Invention

[0003] This application provides an offset information calculation method to improve the efficiency of obtaining offset information between two wafers.

[0004] In a first aspect, embodiments of this application provide an offset information calculation method, comprising: acquiring a first image to be processed and at least one second image to be processed by a vision component between two oppositely placed first wafers and second wafers, wherein the first image to be processed includes an image of a first notch at the edge of the first wafer and an image of a second notch at the edge of the second wafer, and the second image to be processed includes an image of a portion of the edge of the first wafer and an image of a portion of the edge of the second wafer, wherein the first notch and the second notch are symmetrical patterns; processing the first image to be processed to obtain first distance information and angular offset, comprising: determining a first boundary line in the first image to be processed, and identifying images in the first image to be processed located on both sides of the first boundary line and respectively corresponding to the first... First and second contour lines of the edges of a first wafer and a second wafer are defined. Based on the first tangent line at the symmetrical point of the notch in the first contour line and the second tangent line at the symmetrical point of the notch in the mirror image of the second contour line, first distance information and angular offset are determined. The second image to be processed is processed to obtain second distance information. The first distance information and the second distance information respectively represent the offset pixel values ​​of the second wafer relative to the first wafer in the corresponding image to be processed. The first distance information and the second distance information are fitted and calculated to obtain the first lateral offset and the second lateral offset of the second wafer relative to the first wafer. The first lateral offset, the second lateral offset, and the angular offset are used as the offset information.

[0005] According to the aforementioned embodiments of the first aspect of this application, the line connecting any two acquisition locations of the images to be processed does not pass through the center of the first wafer.

[0006] According to any of the foregoing embodiments of the first aspect of this application, determining the first boundary line in the first image to be processed includes: acquiring boundary line information of a visual component, wherein the boundary line information is the position information of the boundary line between two sub-images in the image to be processed acquired by the visual component; and determining the first boundary line in the first image to be processed based on the boundary line information of the visual component acquired from the first image to be processed.

[0007] According to any of the foregoing embodiments of the first aspect of this application, before determining the first distance information and angle offset based on the first tangent at the symmetrical point of the notch in the first contour line and the second tangent at the symmetrical point of the notch in the mirror line of the second contour line, the step of processing the first image to be processed to obtain the first distance information and angle offset further includes: constructing a first mirror line, the first mirror line being axially symmetrical to the second contour line about the first boundary line, the first mirror line having a third notch corresponding to the second notch on the second contour line; obtaining the first tangent at the symmetrical point of the first notch in the first contour line, and obtaining the second tangent at the symmetrical point of the third notch in the first mirror line.

[0008] According to any of the foregoing embodiments of the first aspect of this application, determining the first distance information and the angle offset based on the first tangent at the symmetrical point of the notch in the first contour line and the second tangent at the symmetrical point of the notch in the mirror line of the second contour line includes: constructing a first reference line, the first reference line being perpendicular to the first boundary line and bisecting the first image to be processed; obtaining the first intersection point of the first tangent line and the first reference line, obtaining the second intersection point of the second tangent line and the first reference line, and using the distance between the first intersection point and the second intersection point as the first distance information; and obtaining the angle offset based on the angle between the first tangent line and the second tangent line.

[0009] According to any of the foregoing embodiments of the first aspect of this application, the step of processing the second image to be processed to obtain second distance information includes: determining a second boundary line in the second image to be processed based on the boundary line information of the visual component that acquired the second image to be processed; performing feature recognition in the second image to be processed to obtain a third contour line and a fourth contour line located on both sides of the second boundary line, wherein the third contour line corresponds to a portion of the edge of the first wafer and the fourth contour line corresponds to a portion of the edge of the second wafer; constructing a second mirror line and a second reference line, wherein the second mirror line and the fourth contour line are axially symmetrical about the second boundary line, and the second reference line is parallel to the second boundary line and intersects the third contour line and the second mirror line; obtaining a third intersection point of the third contour line and the second reference line, obtaining a fourth intersection point of the second mirror line and the second reference line, and using the distance between the third intersection point and the fourth intersection point as the second distance information.

[0010] According to any of the foregoing embodiments of the first aspect of this application, the step of fitting and calculating the first distance information and the second distance information to obtain the first lateral offset and the second lateral offset of the second wafer relative to the first wafer includes: obtaining resolution calibration information and coordinate axis calibration information corresponding to the vision component, wherein the resolution calibration information is the mapping relationship between the size of a single pixel in the image to be processed acquired by the vision component and the actual physical size, and the coordinate axis calibration information is the mapping relationship between the rectangular coordinate axis in the image to be processed acquired by the vision component and the first lateral and the second lateral, wherein the first lateral and the second lateral are orthogonal on a plane parallel to the first wafer; and fitting the first lateral offset and the second lateral offset according to the first distance information, the second distance information, the resolution calibration information and the coordinate axis calibration information.

[0011] According to any of the foregoing embodiments of the first aspect of this application, the method further includes: acquiring a third image to be processed by the vision component, and processing the third image to be processed to obtain third distance information, wherein the third image to be processed includes an image of a portion of the first wafer edge and an image of a portion of the second wafer edge; the step of fitting a first lateral offset and a second lateral offset based on the first distance information, the second distance information, the resolution calibration information, and the coordinate axis calibration information includes: fitting a first lateral offset and a second lateral offset based on the first distance information, the second distance information, the third distance information, the resolution calibration information, and the coordinate axis calibration information.

[0012] According to any of the foregoing embodiments of the first aspect of this application, the vision component includes a camera, a light source, a semi-transparent beam splitter, and a beam splitter prism. The camera, the semi-transparent beam splitter, and the beam splitter prism are arranged sequentially along a preset axis. The light source is located on one side of the preset axis, and the light-emitting surface of the light source faces the semi-transparent beam splitter. The emitted light from the light source can be reflected by the semi-transparent beam splitter and projected onto the beam splitter prism. The beam splitter prism can extend between the first wafer and the second wafer placed opposite each other. The beam splitter prism includes a first inclined surface inclined towards the first wafer and a second inclined surface inclined towards the second wafer. The first inclined surface and the second inclined surface are symmetrically arranged. The camera is used to acquire an image to be processed, and the image to be processed includes an image of the first wafer and an image of the second wafer.

[0013] According to any of the foregoing embodiments of the first aspect of this application, obtaining the boundary information of the vision component includes: obtaining a calibration image of a calibration block installed at the beam splitter through the vision component, the calibration block including a first calibration part and a second calibration part symmetrically arranged, the first calibration part and the second calibration part being located on the image acquisition focal plane corresponding to the vision component; and obtaining the boundary information corresponding to the vision component based on the calibration image.

[0014] Secondly, embodiments of this application provide a vision component for a wafer alignment device. The vision component includes a camera, a light source, a semi-transparent beam splitter, and a beam splitter prism. The camera, the semi-transparent beam splitter, and the beam splitter prism are arranged sequentially along a preset axis. The light source is located on one side of the preset axis, and the light-emitting surface of the light source faces the semi-transparent beam splitter. The emitted light from the light source can be reflected by the semi-transparent beam splitter and projected onto the beam splitter prism. The beam splitter prism can extend between a first wafer and a second wafer placed opposite each other. The beam splitter prism includes a first inclined surface inclined towards the first wafer and a second inclined surface inclined towards the second wafer. The first inclined surface and the second inclined surface are symmetrically arranged. The camera is used to acquire an image to be processed, and the image to be processed includes an image of the first wafer and an image of the second wafer.

[0015] According to the foregoing embodiments of the second aspect of this application, the vision component further includes a lens housing and a lens group, wherein the camera and the beam splitter are respectively located at opposite ends of the lens housing, the semi-transparent beam splitter and the lens group are located inside the lens housing, and the lens group is located between the semi-transparent beam splitter and the beam splitter.

[0016] Thirdly, embodiments of this application provide a wafer alignment device, comprising: a base; a first carrier mounted on the base, the first carrier being used to carry a first wafer; a second carrier spaced longitudinally from the first carrier, the second carrier being used to carry a second wafer; an adjustment component mounted on the base and connected to the second carrier, the adjustment component being used to move the second carrier relative to the first carrier; at least two vision components according to the offset information calculation method of any of the foregoing embodiments of the first aspect of this application, distributed around the second carrier, wherein when the first carrier carries the first wafer and the second carrier carries the second wafer, the beam splitter of each vision component is located laterally at the edge of the first wafer and longitudinally between the first wafer and the second wafer, each vision component being used to acquire a corresponding image to be processed; and a control unit communicatively connected to the vision components and the adjustment component, the control unit obtaining offset information of the second wafer relative to the first wafer through the offset information calculation method, the control unit being used to control the adjustment component to move the second carrier according to the offset information, so that the second wafer is aligned with the first wafer.

[0017] According to any of the foregoing embodiments of the third aspect of this application, for any two image acquisition positions of the vision components, the line connecting them does not pass through the center of the first wafer.

[0018] According to any of the foregoing embodiments of the third aspect of this application, the wafer alignment apparatus further includes: a first support member connecting the first carrier member to the base, wherein the first carrier member is located on the side of the second carrier member away from the base.

[0019] According to any of the foregoing embodiments of the third aspect of this application, the adjusting assembly includes a first adjusting seat, a second adjusting seat, and a connecting plate. The first adjusting seat is mounted on the base, the second adjusting seat is mounted on the first adjusting seat, the connecting plate is mounted on the second adjusting seat, and the second bearing member is mounted on the connecting plate. The first adjusting seat is used to drive the second adjusting seat to move along one of a first transverse direction and a second transverse direction, the second adjusting seat is used to drive the connecting plate to move along the other of the first transverse direction and the second transverse direction, and the connecting plate is used to drive the second bearing member to rotate. The first transverse direction and the second transverse direction are orthogonal.

[0020] According to any of the foregoing embodiments of the third aspect of this application, the edge of the first wafer has a first notch, the edge of the second wafer has a second notch, the plurality of vision components include a first vision component, a second vision component, and a third vision component, the first vision component is used to acquire an image to be processed including an image of the first notch and an image of the second notch, the wafer alignment device further includes: a first mounting bracket and a second mounting bracket, the first mounting bracket and the second mounting bracket are respectively disposed on opposite sides of the first carrier, the first vision component is mounted on the base through the first mounting bracket, the second vision component and the third vision component are mounted on the base through the second mounting bracket, and the second vision component and the third vision component are symmetrically arranged on the second mounting bracket.

[0021] Fourthly, embodiments of this application provide a wafer bonding system, which includes a wafer alignment apparatus according to any of the foregoing embodiments of the third aspect of this application.

[0022] Fifthly, embodiments of this application provide a computer-readable storage medium having a computer program / instructions that, when executed by a processor, implement an offset information calculation method according to any of the foregoing embodiments of the first aspect of this application.

[0023] In a sixth aspect, embodiments of this application provide a control unit, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the program, it implements an offset information calculation method according to any of the foregoing embodiments of the first aspect of this application.

[0024] In a seventh aspect, embodiments of this application provide a computer program product, including a computer program / instructions that, when executed by a processor, implement the steps of the offset information calculation method according to any of the foregoing embodiments of the first aspect of this application.

[0025] According to the offset information calculation method of this application embodiment, a first image to be processed and at least one second image to be processed are obtained between a first wafer and a second wafer placed opposite each other; the first image to be processed is processed to obtain first distance information and angular offset; the second image to be processed is processed to obtain second distance information; the first distance information and the second distance information are fitted and calculated to obtain a first lateral offset and a second lateral offset of the second wafer relative to the first wafer, and the first lateral offset, the second lateral offset, and the angular offset are used as offset information. After obtaining the offset information, it is convenient to align the second wafer with the first wafer according to the offset information, thereby realizing the operation of aligning the second wafer with the first wafer. The steps for processing the first image to be processed include: determining a first boundary line in the first image to be processed, and identifying a first contour line and a second contour line located on both sides of the first boundary line and corresponding to the edges of the first and second wafers, respectively. Based on a first tangent line at a symmetrical point of a notch in the first contour line and a second tangent line at a symmetrical point of a notch in the mirror image of the second contour line, the offset-related information in two aspects can be obtained efficiently using the tangent lines, namely, determining the first distance information and the angular offset. The above processing of the first image to be processed improves the efficiency of obtaining offset information, thereby facilitating the improvement of the efficiency of aligning the second wafer with the first wafer. Attached Figure Description

[0026] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0027] Figure 1 This is a perspective schematic diagram of one embodiment of the visual component according to this application;

[0028] Figure 2 This is a frontal view schematic diagram of one embodiment of the visual component according to this application;

[0029] Figure 3 This is a half-section schematic diagram of one embodiment of the visual component according to this application;

[0030] Figure 4 This is a flowchart illustrating one embodiment of the offset information calculation method according to this application;

[0031] Figure 5 This is an image schematic diagram of a first image to be processed, as exemplified in one embodiment of the offset information calculation method of this application;

[0032] Figure 6 This is an example of a second image to be processed in one embodiment of the offset information calculation method of this application;

[0033] Figure 7 This is an image schematic diagram of a third image to be processed, exemplified in one embodiment of the offset information calculation method of this application;

[0034] Figure 8 This is a top view schematic diagram of the step of obtaining a first image to be processed and at least one second image to be processed by a vision component between two relatively placed first and second wafers, according to an embodiment of the offset information calculation method of this application.

[0035] Figure 9 This is a front view schematic diagram of the step of obtaining a first image to be processed and at least one second image to be processed by a vision component between two relatively placed first and second wafers, according to an embodiment of the offset information calculation method of this application.

[0036] Figure 10 This is a three-dimensional schematic diagram of a calibration block in one embodiment of the offset information calculation method according to this application;

[0037] Figure 11 This is a frontal structural diagram of a calibration block installed at a beam splitter when a calibration image is obtained by a vision component in one embodiment of the offset information calculation method of this application.

[0038] Figure 12 This is a flowchart illustrating the process of processing a first image to be processed to obtain first distance information and angle offset in one embodiment of the offset information calculation method of this application.

[0039] Figure 13 This is a schematic diagram of the structure of a first image to be processed, which is processed according to one embodiment of the offset information calculation method of this application.

[0040] Figure 14 This is a flowchart illustrating the process of processing a second image to be processed to obtain second distance information according to one embodiment of the offset information calculation method of this application;

[0041] Figure 15 This is a schematic diagram of the structure of a second image to be processed, which is processed according to one embodiment of the offset information calculation method of this application.

[0042] Figure 16 This is a flowchart illustrating the process of processing a third image to be processed to obtain third distance information according to one embodiment of the offset information calculation method of this application.

[0043] Figure 17 This is a schematic diagram of the structure of a third image to be processed, which is processed according to one embodiment of the offset information calculation method of this application.

[0044] Figure 18 This is a perspective view of one embodiment of the wafer alignment apparatus according to the present application;

[0045] Figure 19 This is a front view schematic diagram of one embodiment of the wafer alignment apparatus according to this application;

[0046] Figure 20 This is a top view schematic diagram of one embodiment of the wafer alignment apparatus according to this application;

[0047] Figure 21 This is a schematic diagram of the electrical connection structure of one embodiment of the wafer alignment apparatus according to this application;

[0048] Figure 22 This is a perspective view of the adjustment component in one embodiment of the wafer alignment apparatus according to this application;

[0049] Figure 23 This is a schematic diagram of the hardware structure of one embodiment of the control unit according to this application. Detailed Implementation

[0050] The technical solutions in the embodiments (or "implementations") of this application will be clearly and completely described herein with reference to the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0051] If the embodiments of this application contain terms relating to directional indications or positional relationships (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationships and movement of the components in a specific posture (as shown in the attached figures); if the specific posture changes, the directional indications or positional relationships will also change accordingly. Furthermore, the terms "first" and "second" used in the embodiments of this application are only for descriptive convenience and should not be construed as indicating or implying relative importance.

[0052] This application provides a vision component for acquiring images that simultaneously contain two wafers. Figure 1 , Figure 2 , Figure 3 These are perspective views, front views, and half-section views of an embodiment of the vision component according to this application. The vision component 100 includes a camera 110, a light source 120, a semi-transparent beam splitter 130, and a beam splitter prism 140, which are arranged sequentially along a preset axis L1.

[0053] The light source 120 is located on one side of the preset axis L1, with its light-emitting surface facing the semi-transparent beam splitter 130. The emitted light from the light source 120 can be reflected by the semi-transparent beam splitter 130 and projected onto the beam splitter 140. The beam splitter 140 can extend between the first wafer and the second wafer, which are placed opposite each other. The beam splitter 140 includes a first inclined surface 141 inclined towards the first wafer and a second inclined surface 142 inclined towards the second wafer, which are symmetrically arranged. The camera 110 is used to acquire images to be processed, which include images of the first wafer and the second wafer. Specifically, each image to be processed includes an image of a portion of the edge of the first wafer and an image of a portion of the edge of the second wafer.

[0054] According to an embodiment of this application, a vision component 100 is used in a wafer alignment apparatus. The vision component 100 includes a camera 110, a light source 120, a semi-transparent beam splitter 130, and a beam splitter 140. The beam splitter 140 can extend between a first wafer and a second wafer placed opposite each other. The beam splitter 140 includes a first inclined surface 141 inclined towards the first wafer and a second inclined surface 142 inclined towards the second wafer, and the first inclined surface 141 and the second inclined surface 142 are symmetrically arranged. The emitted light from the light source 120 is reflected by a semi-transparent beam splitter 130 and projected onto a beam splitter 140. The beam splitter 140 splits the incident light into two, focusing them onto the surfaces of the first wafer and the second wafer, respectively. The light reflected back from both wafers (the first wafer and the second wafer) passes sequentially through the beam splitter 140 and the semi-transparent beam splitter 130 before being imaged by the camera 110. Thus, the image to be processed acquired by the camera 110 includes images of parts of the first wafer edge and parts of the second wafer edge. In this embodiment, a single vision component 100 can acquire images of parts of the first wafer edge and parts of the second wafer edge. By replacing two sets of vision components in a traditional wafer alignment device with a single set of vision components 100, edge images of the first and second wafers can be obtained, thereby reducing the cost of the wafer alignment device and significantly improving image acquisition efficiency.

[0055] In this embodiment, the beam splitter 140 is a triangular prism. The triangle can be an isosceles triangle. When the incident light can be focused onto the wafer surface through the triangular prism, the apex angle of the isosceles triangle can be flexibly selected according to the wafer placement position, angle, etc. For example, it includes one right-angled edge and two 45° angled edges. The right-angled edge of the beam splitter 140 is located on the preset axis L1. The beam splitter 140 is symmetrically arranged between the first wafer and the second wafer to be aligned with each other, about a preset plane that passes through the preset axis L1 and is parallel to the first wafer (and also parallel to the second wafer).

[0056] In some embodiments, the vision component 100 further includes a lens housing 150 and a lens group 160. A camera 110 and a beam splitter 140 are located at opposite ends of the lens housing 150. A semi-transparent beam splitter 130 and the lens group 160 are located within the lens housing 150. The lens group 160 is located between the semi-transparent beam splitter 130 and the beam splitter 140.

[0057] In this embodiment, while maintaining the reflected light from the semi-transparent beam splitter 130 parallel to the preset axis L1, the angle between the semi-transparent beam splitter 130 and the preset axis L1 can be flexibly set as the light emission direction of the light source 120 changes. For example, the semi-transparent beam splitter 130 is set at a 45° angle to the preset axis L1, and the light emission direction of the light source 120 is set at a 45° angle to the semi-transparent beam splitter 130. In this embodiment, the light source 120 is set on one side of the vision component 100, and the incident light is focused onto the two wafer surfaces by the semi-transparent beam splitter 130 and the beam splitter prism 140, which can significantly simplify the light source setup architecture and improve the overall stability of the vision component.

[0058] In some embodiments, the beam splitter 140 can be directly fixedly connected to the lens housing 150. In some embodiments, the beam splitter 140 can be indirectly fixedly connected to the lens housing 150. For example, the beam splitter 140 and the lens housing 150 are spaced apart and connected to each other through other connectors, or connected to other components through other connectors.

[0059] In some embodiments of this application, the vision component 100 can extend between a first wafer and a second wafer to be aligned and acquire an image to be processed. The image to be processed includes images of portions of the first wafer's edge and portions of the second wafer's edge. Embodiments of this application also disclose an offset information calculation method that can determine the offset information between the first wafer and the second wafer based on the image to be processed.

[0060] Figure 4 This is a flowchart illustrating an embodiment of the offset information calculation method according to this application. The offset information calculation method includes steps S110 to S140.

[0061] In step S110, a first image to be processed and at least one second image to be processed are acquired by the vision component between the first wafer and the second wafer, which are placed opposite each other. In this embodiment, the vision component is the vision component 100 of any of the foregoing embodiments. The camera 110 of the vision component 100 is used to acquire the image to be processed, which includes an image of the first wafer and an image of the second wafer. In this embodiment, at least two images to be processed are obtained by the vision component acquiring images at at least two acquisition positions, and these at least two images to be processed include a first image to be processed and at least one second image to be processed. In this embodiment, the first notch and the second notch are both symmetrical patterns.

[0062] Figure 5 This is an image schematic diagram of a first image to be processed, as exemplified in one embodiment of the offset information calculation method of this application. Figure 6 This is a schematic diagram of an example of a second image to be processed according to one embodiment of the offset information calculation method of this application. The first image to be processed includes an image of a first notch at the edge of a first wafer and an image of a second notch at the edge of a second wafer. The second image to be processed includes an image of a portion of the edge of the first wafer and an image of a portion of the edge of the second wafer.

[0063] In this embodiment, the notch includes a physical marker indicating the wafer orientation and located at the edge of the wafer. The wafer can include the wafer itself, or it can include carriers, interposers, etc., that need to be bonded to the wafer / wafer in advanced processes. The wafer shape can be circular, rectangular, etc. In this embodiment, at least two images to be processed can be acquired. The first image to be processed is acquired at the notch, and other images to be processed can be acquired as needed at other edges of the wafer, such as the smooth edge of a circular wafer, the corner of a rectangular wafer, or other smooth edges. This can be determined according to actual needs and is not limited here.

[0064] Optionally, in some embodiments, the offset information calculation method further includes: acquiring a third image to be processed by the vision component. Figure 7 This is a schematic diagram of a third image to be processed, exemplified in one embodiment of the offset information calculation method of this application. The third image to be processed includes images of a portion of the first wafer edge and images of a portion of the second wafer edge.

[0065] Figure 8 , Figure 9This document presents a top view and a front view schematic diagram illustrating the step of acquiring a first image to be processed and at least one second image to be processed by a vision component between two relatively placed wafers, according to an embodiment of the offset information calculation method of this application. The images to be processed can be acquired in various ways, such as by acquiring images separately at different positions using at least two vision components, or by rotating and moving a single vision component along the edge of the wafer to sequentially acquire images at different positions. The line connecting the acquisition positions of any two images to be processed does not pass through the center of the wafer.

[0066] like Figure 8 , Figure 9 In one example, the vision component 100 acquires images at three acquisition positions: a first acquisition position TP1, a second acquisition position TP2, and a third acquisition position TP3, respectively, to obtain three images to be processed. These three images are, for example, the first image to be processed, the second image to be processed, and the third image to be processed. The line connecting any two acquisition positions TP1, TP2, and TP3 does not pass through the wafer center. The number of vision components 100 can be at least two; for example, vision components 100 can be located at each of the three acquisition positions TP1, TP2, and TP3. The beam splitter prism 140 of each vision component 100 is located laterally at the edge of the first wafer W1 and longitudinally between the first wafer W1 and the second wafer W2. Each vision component 100 is used to acquire the image to be processed at the corresponding acquisition position.

[0067] In an alternative example, the vision component 100 acquires images at a first acquisition position TP1 and a second acquisition position TP2, respectively, to obtain two images to be processed, such as a first image to be processed and a second image to be processed. The line connecting the first acquisition position TP1 and the second acquisition position TP2 does not pass through the wafer center.

[0068] In an alternative example, the number of vision components 100 is single, which is configured to rotate and move at the edge of the first wafer, and sequentially acquire images at different positions, such as a first acquisition position TP1, a second acquisition position TP2, and a third acquisition position TP3, to obtain three images to be processed, such as the first image to be processed, the second image to be processed, and the third image to be processed. The line connecting any two acquisition positions TP1, TP2, and TP3 does not pass through the center of the wafer.

[0069] like Figure 4In step S120, the first image to be processed is processed to obtain first distance information and angle offset. The first distance information represents the offset pixel value of the second wafer relative to the first wafer in the first image to be processed.

[0070] In this embodiment, step 120 of processing the first image to be processed to obtain the first distance information and angle offset includes: determining a first boundary line in the first image to be processed, and identifying a first contour line and a second contour line located on both sides of the first boundary line in the first image to be processed, and corresponding to the edge of the first wafer and the edge of the second wafer respectively; determining the first distance information and angle offset based on the first tangent line at the symmetrical point of the notch in the first contour line and the second tangent line at the symmetrical point of the notch in the mirror line of the second contour line.

[0071] In some embodiments, the step of determining a first boundary line in a first image to be processed may include: acquiring boundary line information of a vision component, wherein the boundary line information is the position information of the boundary line between two sub-images in the image to be processed acquired by the vision component; and determining a first boundary line in the first image to be processed based on the boundary line information of the vision component acquired from the first image to be processed.

[0072] There are multiple ways to process an image to obtain distance information and angle offset. For example, a neural network model can be built and trained (such as feature extraction through an encoder, feature optimization through spatial attention, pooling, global information extraction, etc., and outputting distance information and angle offset through a multilayer perceptron). The image to be processed can be input into the trained neural network model to obtain distance information, angle offset, etc.

[0073] Due to the symmetrical arrangement of the beam splitter 140 in the vision component 100 in this embodiment, the images to be processed all include images of the upper and lower wafers (the first wafer and the second wafer) at mutually symmetrical positions. If the upper and lower wafers are perfectly aligned, the features of the upper and lower wafers in the image (such as edge lines, positioning marks, and notches) should also be symmetrical in the image. If the upper and lower wafers are offset, the features of the upper and lower wafers will also be offset in the image. Therefore, this embodiment can also utilize this point to calculate the offset information of the upper and lower wafers in physical space based on the offset of the features in the image.

[0074] Specifically, the boundary information of the vision component 100 can be obtained. The boundary information is the position information of the boundary line between two sub-images in the image to be processed acquired by the vision component 100. One of the two sub-images is acquired via the first inclined plane 141, and the other is acquired via the second inclined plane 142. In some embodiments, the boundary information may include the coordinate information of the axis of symmetry of the two sub-images, such as the coordinate information of the midpoint of the image in the horizontal direction, so as to divide the boundary line on the corresponding image based on the coordinate information.

[0075] Based on the boundary line information, the boundary line can be divided into two parts of the image to be processed. Through feature recognition, two contour lines located on both sides of the image to be processed are obtained. The two contour lines correspond to the partial edges of the upper and lower wafers, respectively. Then, based on the principle of axial symmetry, a mirror line of one contour line on the other side of the boundary line is determined. Finally, by the positional difference between the mirror line and the contour line located on the same side of the boundary line, the angular offset and distance information of the image dimension are determined.

[0076] For example, for a first image to be processed containing a notch, a first reference line can be constructed, which is perpendicular to the first dividing line and bisects the first image to be processed; a first tangent line at the symmetrical point of the first notch in the first contour line can be obtained, and a second tangent line at the symmetrical point of the third notch in the first mirror line can be obtained; a first intersection point of the first tangent line and the first reference line can be obtained, and a second intersection point of the second tangent line and the first reference line can be obtained, with the distance between the first intersection point and the second intersection point used as the first distance information; and the angle offset can be obtained based on the angle between the first tangent line and the second tangent line.

[0077] In some embodiments, the steps of processing the first image to be processed to obtain the first distance information and angle offset may include: acquiring the boundary line information of the visual component, wherein the boundary line information is the position information of the boundary line between two sub-images in the image to be processed acquired by the visual component 100, and the visual component may be the visual component 100 of any of the preceding embodiments, wherein one of the two sub-images is acquired via the first inclined plane 141 and the other is acquired via the second inclined plane 142; determining the first boundary line in the first image to be processed based on the boundary line information of the visual component that acquired the first image to be processed; and processing the first image to be processed based on the first boundary line to obtain the first distance information and angle offset.

[0078] The vision component can be any of the vision components 100 described in the preceding embodiments. The vision component 100 includes a camera 110, a light source 120, a semi-transparent beam splitter 130, and a beam splitter 140. The camera 110, semi-transparent beam splitter 130, and beam splitter 140 are arranged sequentially along a preset axis L1. The light source 120 is located on one side of the preset axis L1, with its light-emitting surface facing the semi-transparent beam splitter 130. The emitted light from the light source 120 can be reflected by the semi-transparent beam splitter 130 and projected onto the beam splitter 140. The beam splitter 140 can extend between a first wafer and a second wafer placed opposite each other. The beam splitter 140 includes a first inclined surface 141 inclined towards the first wafer and a second inclined surface 142 inclined towards the second wafer, symmetrically arranged. The camera 110 is used to acquire an image to be processed, which includes images of the first wafer and the second wafer.

[0079] In some embodiments, the step of obtaining the boundary information of the vision component may include: obtaining a calibration image of a calibration block installed at the beam splitter through the vision component, the calibration block including a first calibration part and a second calibration part symmetrically arranged, the first calibration part and the second calibration part being located on the image acquisition focal plane of the corresponding vision component; and obtaining the boundary information corresponding to the vision component based on the calibration image.

[0080] Figure 10 This is a three-dimensional schematic diagram of a calibration block in one embodiment of the offset information calculation method according to this application. Figure 11 This is a frontal structural diagram illustrating the acquisition of a calibration image of a calibration block mounted at a beam splitter using a vision component in one embodiment of the offset information calculation method according to this application. Figure 10 The light rays are indicated by dashed lines. The calibration block 900 includes a first calibration section 910 and a second calibration section 920 symmetrically arranged. When calibrating the vision component 100 to obtain boundary line information, the calibration block 900 can be installed at the beam splitter 140. With the calibration block 900 installed at the beam splitter 140, both the first calibration section 910 and the second calibration section 920 are located on the image acquisition focal plane of the corresponding vision component 100. With the calibration block 900 installed at the beam splitter 140, the vision component 100 acquires a calibration image of the calibration block 900 installed at the beam splitter 140, and then obtains the boundary line information corresponding to the vision component 100 based on this calibration image.

[0081] like Figure 8 In this embodiment, at least two visual components 100, including a first visual component 100a, a second visual component 100b, and a third visual component 100c, are used as an example. The first visual component 100a, the second visual component 100b, and the third visual component 100c are sequentially located at a first acquisition position TP1, a second acquisition position TP2, and a third acquisition position TP3. In one example, the boundary line information of the first visual component 100a, the second visual component 100b, and the third visual component 100c are denoted as T1, T2, and T3, respectively. In one example, the boundary line information can be the endpoint coordinates (in the camera world) of the boundary line between two sub-images in the image to be processed.

[0082] In this embodiment, both the first notch and the second notch are symmetrical patterns.

[0083] Figure 12 This is a flowchart illustrating the process of processing a first image to be processed to obtain first distance information and angular offset, according to one embodiment of the offset information calculation method of this application. Figure 13This is a schematic diagram of the structure of a first image to be processed, processed according to one embodiment of the offset information calculation method of this application. In some embodiments, the first image to be processed may be rotated first; in some embodiments, the first image to be processed may not be rotated. This embodiment describes the process without rotating the first image to be processed. The steps of processing the first image to be processed to obtain the first distance information and the angle offset may include steps S121 to S125.

[0084] In step S121, a first dividing line T1 is determined in the first image to be processed.

[0085] In step S122, a first contour line Q1 and a second contour line Q2 are identified in the first image to be processed, located on both sides of the first boundary line T1 and corresponding to the edges of the first wafer W1 and the second wafer W2, respectively. The first contour line Q1 corresponds to a portion of the edge of the first wafer W1, and the second contour line Q2 corresponds to a portion of the edge of the second wafer W2.

[0086] Then, in step S125, the first distance information dy1 and the angle offset U are determined based on the first tangent K1 at the symmetrical point of the notch in the first contour line Q1 and the second tangent K2 at the symmetrical point of the notch in the mirror line of the second contour line Q2.

[0087] In this embodiment, before step S125, which determines the first distance information dy1 and the angle offset U based on the first tangent K1 at the symmetrical point of the notch in the first contour line Q1 and the second tangent K2 at the symmetrical point of the notch in the mirror line of the second contour line Q2, the first image to be processed is further processed to obtain the first distance information and the angle offset by steps S123 and S124.

[0088] In step S123, a first mirror line P1 is constructed. The first mirror line P1 is symmetrical to the second contour line Q2 about the first boundary line T1, and the first mirror line P1 has a third notch J3 that mirrors the second notch J2 on the second contour line Q2.

[0089] In step S124, the first tangent line K1 in the first contour line Q1 at the symmetrical point R1 of the first notch J1 is obtained, and the second tangent line K2 in the first mirror line P1 at the symmetrical point R3 of the third notch J3 is obtained.

[0090] In this embodiment, step S125, which determines the first distance information dy1 and the angle offset U based on the first tangent K1 at the symmetrical point of the notch in the first contour line Q1 and the second tangent K2 at the symmetrical point of the notch in the mirror line of the second contour line Q2, may include: constructing a first reference line V1, which is perpendicular to the first dividing line T1 and bisects the first image to be processed; obtaining the first intersection point F1 of the first tangent K1 and the first reference line V1, obtaining the second intersection point F2 of the second tangent K2 and the first reference line V1, and using the distance between the first intersection point F1 and the second intersection point F2 as the first distance information dy1; and obtaining the angle offset U based on the angle between the first tangent K1 and the second tangent K2.

[0091] like Figure 4 In step S130, the second image to be processed is processed to obtain second distance information. The first distance information and the second distance information respectively represent the offset pixels of the second wafer relative to the first wafer in the corresponding image to be processed. Therefore, the second distance information represents the offset pixels of the second wafer relative to the first wafer in the second image to be processed.

[0092] Figure 14 This is a flowchart illustrating the process of processing a second image to obtain second distance information according to one embodiment of the offset information calculation method of this application. Figure 15 This is a schematic diagram of the structure of a second image to be processed, processed according to one embodiment of the offset information calculation method of this application. In some embodiments, the second image to be processed may be rotated first; in some embodiments, the second image to be processed may not be rotated. This embodiment illustrates the process of first rotating the second image to be processed 90° clockwise.

[0093] In some embodiments, the step of processing the second image to obtain the second distance information may include steps S131 to S134.

[0094] In step S131, a second boundary line T2 is determined in the second image to be processed based on the boundary line information of the visual component 100 that acquires the second image to be processed.

[0095] In step S132, feature recognition is performed on the second image to be processed to obtain the third contour line Q3 and the fourth contour line Q4 located on both sides of the second boundary line T2. The third contour line Q3 corresponds to a portion of the edge of the first wafer W1, and the fourth contour line Q4 corresponds to a portion of the edge of the second wafer W2.

[0096] In step S133, a second mirror line P2 and a second reference line V2 are constructed. The second mirror line P2 is symmetrical to the fourth contour line Q4 about the second boundary line T2, and the second reference line V2 is parallel to the second boundary line T2 and intersects the third contour line Q3 and the second mirror line P2.

[0097] In step S134, the third intersection point F3 of the third contour line Q3 and the second reference line V2 is obtained, and the fourth intersection point F4 of the second mirror line P2 and the second reference line V2 is obtained. The distance between the third intersection point F3 and the fourth intersection point F4 is used as the second distance information dy2.

[0098] Optionally, in some embodiments, the offset information calculation method further includes: acquiring a third image to be processed by a vision component, and processing the third image to be processed to obtain third distance information, wherein the third image to be processed includes an image of a portion of the first wafer edge and an image of a portion of the second wafer edge.

[0099] Figure 16 This is a flowchart illustrating the process of processing a third image to obtain third distance information according to one embodiment of the offset information calculation method of this application. Figure 17 This is a schematic diagram of the structure of a third image to be processed, processed according to one embodiment of the offset information calculation method of this application. In some embodiments, the third image to be processed may be rotated first; in some embodiments, the third image to be processed may not be rotated. This embodiment illustrates the process of first rotating the third image to be processed counterclockwise by 90° as an example.

[0100] In some embodiments, processing the third image to be processed to obtain third distance information may include steps S161 to S164.

[0101] In step S161, a third boundary line T3 is determined in the third image to be processed based on the boundary line information of the visual component 100 that acquires the third image to be processed.

[0102] In step S162, feature recognition is performed in the third image to be processed to obtain the fifth contour line Q5 and the sixth contour line Q6 located on both sides of the third boundary line T3. The fifth contour line Q5 corresponds to a portion of the edge of the first wafer W1, and the sixth contour line Q6 corresponds to a portion of the edge of the second wafer W2.

[0103] In step S163, a third mirror line P3 and a third reference line V3 are constructed. The third mirror line P3 is symmetrical to the sixth contour line Q6 about the third boundary line T3, and the third reference line V3 is parallel to the third boundary line T3 and intersects the fifth contour line Q5 and the third mirror line P3.

[0104] In step S164, the fifth intersection point F5 of the fifth contour line Q5 and the third reference line V3 is obtained, and the sixth intersection point F6 of the third mirror line P3 and the third reference line V3 is obtained. The distance between the fifth intersection point F5 and the sixth intersection point F6 is used as the third distance information dy3.

[0105] In step S140, the first distance information and the second distance information are fitted and calculated to obtain the first lateral offset and the second lateral offset of the second wafer relative to the first wafer, and the first lateral offset, the second lateral offset, and the angle offset are used as offset information.

[0106] There are multiple ways to implement this, such as using large models, intelligent agents, machine learning models, deep learning models, etc., to enable them to learn and have the ability to directly output offset information through a certain amount of sample data.

[0107] Alternatively, a system of equations can be solved or fitted based on at least two pieces of distance information, the resolution calibration information of the visual components, and the coordinate axis calibration information to obtain the first lateral offset N1 and the second lateral offset N2. Fitting algorithms include least squares, regression, and probability distribution algorithms, which can be flexibly selected according to the specific requirements.

[0108] In some embodiments, step S130, which involves fitting and calculating the first distance information dy1 and the second distance information dy2 to obtain the first lateral offset N1 and the second lateral offset N2 of the second wafer relative to the first wafer, includes: obtaining the resolution calibration information and coordinate axis calibration information corresponding to the visual component; and fitting the first lateral offset N1 and the second lateral offset N2 based on the first distance information dy1, the second distance information dy2, the resolution calibration information, and the coordinate axis calibration information.

[0109] Resolution calibration information is the mapping relationship between the size of a single pixel in the image to be processed acquired by the vision component 100 and its actual physical size. In one example, taking at least two vision components 100, including a first vision component 100a, a second vision component 100b, and a third vision component 100c, the resolution calibration information of the first vision component 100a, the second vision component 100b, and the third vision component 100c is denoted as Size1, Size2, and Size3, respectively. An example of Size1 for the resolution calibration information of the first vision component 100a is 2µm / pixel.

[0110] The coordinate axis calibration information is the mapping relationship between the Cartesian coordinate axes in the image to be processed acquired by the vision component 100 and the first horizontal X and second horizontal Y axes, which are orthogonal on a plane parallel to the first wafer W1. That is, the coordinate axis calibration information is the mapping relationship between the two Cartesian coordinate axes of each vision component 100 in the camera world and the first horizontal X and second horizontal Y axes in the real world. In one example, taking at least two vision components 100, including a first vision component 100a, a second vision component 100b, and a third vision component 100c, the coordinate axis calibration information of the first vision component 100a is denoted as AxisX1 and AxisY1; the coordinate axis calibration information of the second vision component 100b is denoted as AxisX2 and AxisY2; and the coordinate axis calibration information of the third vision component 100c is denoted as AxisX3 and AxisY3.

[0111] Optionally, in some embodiments described above, the offset information calculation method further includes: acquiring a third image to be processed by the vision component, and processing the third image to be processed to obtain third distance information dy3, wherein the third image to be processed includes images of a portion of the first wafer edge and images of a portion of the second wafer edge. In this case, the step of fitting the first lateral offset N1 and the second lateral offset N2 based on the first distance information dy1, the second distance information dy2, the resolution calibration information, and the coordinate axis calibration information may include: fitting the first lateral offset N1 and the second lateral offset N2 based on the first distance information dy1, the second distance information dy2, the third distance information dy3, the resolution calibration information, and the coordinate axis calibration information.

[0112] In one example, the first distance information dy1, the second distance information dy2, the third distance information dy3, the complete resolution calibration information Size1, Size2, Size3, and the complete coordinate axis calibration information AxisX1, AxisY1, AxisX2, AxisY2, AxisX3, AxisY3 are related to the first lateral offset N1 and the second lateral offset N2 as follows:

[0113]

[0114] In one example, based on the relationship in the above formula, the first lateral offset N1 and the second lateral offset N2 are obtained by fitting using the least squares method. In other embodiments, the first lateral offset N1 and the second lateral offset N2 can also be obtained by fitting using other alternative fitting algorithms.

[0115] According to the offset information calculation method of this application embodiment, at each image acquisition position, a single set of vision components 100 can simultaneously acquire images of part of the edge of the first wafer W1 and part of the edge of the second wafer W2. By replacing two sets of vision components in a traditional wafer alignment device with a single set of vision components 100, edge images of the first wafer W1 and the second wafer W2 can be obtained, thereby reducing the cost of the wafer alignment device and significantly improving image acquisition efficiency. According to the offset information calculation method of this application embodiment, a first image to be processed and at least one second image to be processed acquired by the vision components are acquired; the first image to be processed is processed to obtain first distance information and angular offset; the second image to be processed is processed to obtain second distance information; the first distance information and the second distance information are fitted and calculated to obtain a first lateral offset and a second lateral offset of the second wafer relative to the first wafer, and the first lateral offset, the second lateral offset, and the angular offset are used as offset information. After obtaining the offset information, it is convenient to align the second wafer W2 with the first wafer W1 according to the offset information, thus realizing the operation of aligning the second wafer W2 with the first wafer W1.

[0116] According to the offset information calculation method of this application embodiment, a first image to be processed and at least one second image to be processed are acquired by a vision component between a first wafer W1 and a second wafer W2 placed opposite each other; the first image to be processed is processed to obtain first distance information and angular offset; the second image to be processed is processed to obtain second distance information; the first distance information and the second distance information are fitted and calculated to obtain a first lateral offset and a second lateral offset of the second wafer relative to the first wafer, and the first lateral offset, the second lateral offset, and the angular offset are used as offset information. After obtaining the offset information, it is convenient to align the second wafer W2 with the first wafer W1 according to the offset information, thereby realizing the operation of aligning the second wafer W2 with the first wafer W1. The steps for processing the first image to be processed include: determining a first boundary line T1 in the first image to be processed, and identifying a first contour line Q1 and a second contour line Q2 located on both sides of the first boundary line T1 and corresponding to the edges of the first wafer W1 and the second wafer W2, respectively. Based on the first tangent line K1 at the symmetrical point of the notch in the first contour line Q1 and the second tangent line K2 at the symmetrical point of the notch in the mirror line of the second contour line Q2, the offset-related information in two aspects can be obtained efficiently using the tangent lines, namely, determining the first distance information dy1 and the angular offset U. The above processing of the first image to be processed improves the efficiency of obtaining offset information, thereby facilitating the improvement of the efficiency of aligning the second wafer W2 with the first wafer W1.

[0117] This application also provides a wafer alignment apparatus. The wafer alignment apparatus includes a base, two carriers that respectively support upper and lower wafers, a vision component that acquires images that simultaneously include partial edge regions of the upper and lower wafers, a control unit that calculates offset information between the upper and lower wafers based on the images to be processed, and an adjustment component that adjusts the wafer position to align the upper and lower wafers.

[0118] Specifically, the vision components can be mounted on the base of the wafer alignment device in a variety of ways.

[0119] In some embodiments, at least two vision components are disposed at different acquisition positions on the wafer edge of the wafer alignment device. For example, two vision components are mounted on a base and sequentially located at a first acquisition position and a second acquisition position. The two vision components acquire images of the upper and lower wafers at the first acquisition position and the second acquisition position, respectively, to obtain two images to be processed, such as a first image to be processed and a second image to be processed. The line connecting the first acquisition position and the second acquisition position does not pass through the center of the wafer. For example, three vision components are mounted on a base and sequentially located at a first acquisition position, a second acquisition position, and a third acquisition position. The vision components at the first acquisition position, the second acquisition position, and the third acquisition position acquire images of the upper and lower wafers to obtain three images to be processed, such as a first image to be processed, a second image to be processed, and a third image to be processed. The line connecting any two acquisition positions does not pass through the center of the wafer.

[0120] In some embodiments, a single vision component is mounted on the base of the wafer alignment device via a movable element that moves the vision component along the wafer edge. In one example, the movable element is a sliding component. For instance, the movable element can move the vision component to a first acquisition position and a second acquisition position. When the vision component pauses at the first and second acquisition positions, it acquires images of the upper and lower wafers respectively, resulting in two images to be processed. Alternatively, the movable element can move the vision component to a first acquisition position, a second acquisition position, and a third acquisition position. When the vision component pauses at these positions, it acquires images of the upper and lower wafers respectively, resulting in three images to be processed.

[0121] Figure 18 , Figure 19 , Figure 20 These are perspective views, front views, and top views of one embodiment of the wafer alignment apparatus according to this application. Figure 21This is a schematic diagram of the electrical connection structure of one embodiment of the wafer alignment apparatus according to this application. The wafer alignment apparatus includes a base 200, a first support 300, a second support 400, an adjustment assembly 500, at least two vision components 100, and a control unit 600.

[0122] The vision component 100 is the vision component 100 of any of the foregoing embodiments, or the vision component 100 in the offset information calculation method of any of the foregoing embodiments. The control unit 600 obtains the offset information of the second wafer W2 relative to the first wafer W1 through the offset information calculation method of any of the foregoing embodiments.

[0123] A first support member 300 is mounted on a base 200 and is used to support a first wafer W1. A second support member 400 is longitudinally spaced from the first support member 300 and is used to support a second wafer W2. An adjustment assembly 500 is mounted on the base 200 and connected to the second support member 400. The adjustment assembly 500 is used to move the second support member 400 relative to the first support member 300.

[0124] Each vision component 100 includes a camera 110, a light source 120, a semi-transparent beam splitter 130, and a beam splitter 140, arranged sequentially along a preset axis L1. The light source 120 is located on one side of the preset axis L1, with its light-emitting surface facing the semi-transparent beam splitter 130. The emitted light from the light source 120 can be reflected by the semi-transparent beam splitter 130 and projected onto the beam splitter 140. The beam splitter 140 extends between a first wafer W1 and a second wafer W2 placed opposite each other. The beam splitter 140 includes a first inclined surface 141 inclined towards the first wafer and a second inclined surface 142 inclined towards the second wafer, symmetrically arranged. The camera 110 is used to acquire an image to be processed, which includes images of the first wafer and the second wafer.

[0125] At least two vision components 100 are distributed around the second carrier 400. With the first carrier 300 carrying the first wafer W1 and the second carrier 400 carrying the second wafer W2, the beam splitter 140 of each vision component 100 is positioned laterally at the edge of the first wafer W1 and longitudinally between the first wafer W1 and the second wafer W2. Each vision component 100 is used to acquire a corresponding image to be processed. The image to be processed includes images of portions of the edges of the first wafer W1 and portions of the edges of the second wafer W2.

[0126] The control unit 600 is communicatively connected to the vision component 100 and the adjustment component 500. The control unit 600 obtains the offset information of the second wafer W2 relative to the first wafer W1 using the offset information calculation method of any of the foregoing embodiments. The control unit 600 controls the adjustment component 500 to move the second carrier 400 according to the offset information, so that the second wafer W2 is aligned with the first wafer W1.

[0127] The control unit 600 can be a host computer, a dedicated server, or other computer equipment, or other electronic devices capable of executing computer programs.

[0128] According to an embodiment of this application, a wafer alignment apparatus includes a first support 300, a second support 400, an adjustment component 500, at least two vision components 100, and a control unit 600. The first support 300 is used to support a first wafer W1, and the second support 400 is used to support a second wafer W2. Each vision component 100 includes a camera 110, a light source 120, a semi-transparent beam splitter 130, and a beam splitter 140. The beam splitter 140 can extend between the opposing first wafer W1 and second wafer W2. The beam splitter 140 includes a first inclined surface 141 inclined towards the first wafer W1 and a second inclined surface 142 inclined towards the second wafer W2, and the first inclined surface 141 and the second inclined surface 142 are symmetrically arranged. The beam splitter 140 of each vision component 100 is located laterally at the edge of the first wafer W1 and longitudinally between the first wafer W1 and the second wafer W2. Each vision component 100 is used to acquire a corresponding image to be processed. Camera 110 acquires the image to be processed via beam splitter 140. The image to be processed includes images of a portion of the edge of the first wafer W1 and a portion of the edge of the second wafer W2. In this embodiment, at each image acquisition location, a single set of vision components 100 can simultaneously acquire images of a portion of the edge of the first wafer W1 and a portion of the edge of the second wafer W2. By replacing two sets of vision components in a traditional wafer alignment device with a single set of vision components 100, the edge images of the first wafer W1 and the second wafer W2 are acquired, thereby reducing the cost of the wafer alignment device and significantly improving image acquisition efficiency. Control unit 600 can acquire the offset information of the second wafer W2 relative to the first wafer W1. Control unit 600 can control adjustment component 500 to move the second carrier 400 according to the offset information, so that the second wafer W2 is aligned with the first wafer W1, realizing the operation of aligning the second wafer W2 with the first wafer W1.

[0129] For any two image acquisition positions of the vision components 100, the line connecting them does not pass through the center of the first wafer W1. For example... Figures 18 to 21In one example, the number of vision components 100 is three. Taking at least two vision components 100, including a first vision component 100a, a second vision component 100b, and a third vision component 100c, as an example, the first vision component 100a, the second vision component 100b, and the third vision component 100c are sequentially arranged at the first acquisition position, the second acquisition position, and the third acquisition position. Among the first acquisition position, the second acquisition position, and the third acquisition position, the line connecting any two acquisition positions does not pass through the center of the first wafer W1.

[0130] In an alternative example, there are two vision components 100, which are sequentially positioned at a first acquisition position and a second acquisition position. The connection between the first acquisition position and the second acquisition position does not pass through the center of the first wafer. The number of vision components 100 can also be, for example, four, five, or other numbers, and the connection between the image acquisition positions of any two vision components 100 does not pass through the center of the first wafer W1.

[0131] In yet another alternative example, the vision component 100 is a single unit, configured to rotate and move along the edge of the first wafer, sequentially acquiring images at different locations, such as a first acquisition position, a second acquisition position, and a third acquisition position, resulting in three images to be processed. The line connecting any two of the first, second, and third acquisition positions does not pass through the center of the first wafer. Alternatively, the vision component 100 rotates and moves along the edge of the first wafer, sequentially acquiring images at a first and a second acquisition position, resulting in two images to be processed. The line connecting the first and second acquisition positions does not pass through the center of the first wafer.

[0132] In some embodiments, the wafer alignment apparatus further includes a first support 700. The first support 700 connects the first carrier 300 to the base 200. The first carrier 300 is located on the side of the second carrier 400 away from the base 200. The number of first supports 700 can be single or more than two. In one example, the wafer alignment apparatus includes two first supports 700, which are symmetrically or uniformly distributed around the outer periphery of the first carrier 300.

[0133] In the above embodiment, the first support member 700 connects the first carrier member 300 to the base 200, which can ensure the positional stability of the first carrier member 300 and make the first carrier member 300 stably suspended on the side of the second carrier member 400 away from the base 200.

[0134] In some embodiments, the second carrier 400 can limit the position of the second wafer W2 it carries, so that when the adjusting component 500 moves the second carrier 400, the second wafer W2 can move synchronously with the second carrier 400. For example, the second carrier 400 limits the position of the second wafer W2 by a known vacuum adsorption method, so that the second wafer W2 is adsorbed onto the second carrier 400.

[0135] Figure 22 This is a perspective view of an adjustment component in one embodiment of the wafer alignment apparatus according to this application. In some embodiments, the adjustment component 500 includes a first adjustment seat 510, a second adjustment seat 520, and a connecting plate 530. The first adjustment seat 510 is mounted on a base 200, the second adjustment seat 520 is mounted on the first adjustment seat 510, the connecting plate 530 is mounted on the second adjustment seat 520, and the second support member 400 is mounted on the connecting plate 530.

[0136] The first adjusting seat 510 is used to move the second adjusting seat 520 along one of the first horizontal direction X and the second horizontal direction Y. The second adjusting seat 520 is used to move the connecting plate 530 along the other of the first horizontal direction X and the second horizontal direction Y. The connecting plate 530 is used to rotate the second bearing member 400, and the first horizontal direction X and the second horizontal direction Y are orthogonal. In this embodiment, the rotation center line of the connecting plate 530 driving the second bearing member 400 to rotate is perpendicular to the plane where the second bearing plate is located, and this rotation center line is basically located at the center of the second bearing plate.

[0137] The adjustment assembly 500 includes a first adjustment seat 510, a second adjustment seat 520, and a connecting disk 530. The first adjustment seat 510 and the second adjustment seat 520 enable the second carrier 400, together with the second wafer W2, to translate along a first horizontal direction X and a second horizontal direction Y, so that the planar position of the second wafer W2 can be aligned with the planar position of the first wafer W1. The connecting disk 530 enables the second carrier 400, together with the second wafer W2, to rotate, so that the second wafer W2 can be aligned with the first wafer W1 in an angular dimension.

[0138] The control unit 600 sends an adjustment command to the controller (not shown) of the adjustment component 500 based on the offset information. The controller of the adjustment component 500 can move the first adjustment seat 510, the second adjustment seat 520, and / or the connecting disk 530 based on the adjustment command to adjust the pose of the second carrier 400 together with the second wafer W2. In other embodiments, the pose of the second carrier 400 together with the second wafer W2 can also be adjusted manually by adjusting the adjustment knobs on the first adjustment seat 510, the second adjustment seat 520, and the connecting disk 530 according to the offset information.

[0139] The edge of the first wafer W1 has a first notch, and the edge of the second wafer W2 has a second notch. In this embodiment, the plurality of vision components 100 include a first vision component 100a, a second vision component 100b, and a third vision component 100c. The first vision component 100a is used to acquire an image to be processed, including an image with the first notch and an image with the second notch.

[0140] In some embodiments, the wafer alignment apparatus further includes a first mounting bracket 810 and a second mounting bracket 820, which are respectively disposed on opposite sides of the first support member 300. A first vision component 100a is mounted on the base 200 via the first mounting bracket 810. A second vision component 100b and a third vision component 100c are mounted on the base 200 via the second mounting bracket 820, and are symmetrically arranged on the second mounting bracket 820.

[0141] In one example, the first mounting bracket 810 and the second mounting bracket 820 are respectively disposed on opposite sides of the first support member 300 along the first transverse direction X. Therefore, the first visual component 100a is located on one side of the first support member 300 along the first transverse direction X, and the second visual component 100b and the third visual component 100c are located on the other side of the first support member 300 along the first transverse direction X. The second visual component 100b and the third visual component 100c are spaced apart on the second transverse direction Y.

[0142] In the above embodiment, the plurality of vision components 100 include a first vision component 100a, a second vision component 100b, and a third vision component 100c. The first vision component 100a, the second vision component 100b, and the third vision component 100c are respectively located at different positions in the circumferential direction of the first wafer W1, thereby enabling the acquisition of images to be processed at three positions in the circumferential direction. The image to be processed acquired by the first vision component 100a includes images of the first notch and the second notch. By acquiring the images to be processed at three positions in the circumferential direction, the control unit 600 can process the plurality of images to be processed to obtain offset information, and then control the adjustment component 500 to move the second carrier 400 according to the offset information, thereby aligning the second wafer W2 with the first wafer W1.

[0143] In some embodiments, the first mounting bracket 810 can drive the first vision component 100a to translate, and the second mounting bracket 820 can drive the second vision component 100b and the third vision component 100c to translate. For example, the wafer alignment apparatus further includes a first translation component (not shown) and a second translation component (not shown). The first translation component is drivenly connected to the first mounting bracket 810 and is used to drive the first mounting bracket 810 and the first vision component 100a to translate. The second translation component is drivenly connected to the second mounting bracket 820 and is used to drive the second mounting bracket 820 and the second vision component 100b and the third vision component 100c to translate. During the wafer alignment stage, the beam splitters 140 of the first vision component 100a, the second vision component 100b, and the third vision component 100c extend between the first wafer W1 and the second wafer W2 and are located at the edges of the first wafer W1 and the second wafer W2. In other stages of the non-wafer alignment stage, such as the loading stage, the beam splitting prisms 140 of the first vision component 100a, the second vision component 100b, and the third vision component 100c are removed from between the first wafer W1 and the second wafer W2, that is, the beam splitting prisms 140 of the first vision component 100a, the second vision component 100b, and the third vision component 100c are translated away from the first carrier 300.

[0144] In some embodiments, the wafer alignment apparatus further includes a tilt adjustment component (not shown) and a height adjustment component (not shown). The tilt adjustment component and the height adjustment component are connected to the vision component 100. The tilt adjustment component is used to adjust the tilt angle of the preset axis L1 of the vision component 100 relative to the first wafer W1 (or adjust the tilt angle of the preset axis L1 of the vision component 100 relative to the second wafer W2, or adjust the tilt angle of the preset axis L1 of the vision component 100 relative to the horizontal plane). The height adjustment component is used to adjust the height position of the vision component 100 in the direction perpendicular to the first wafer W1. In one example, the first vision component 100a is mounted on the first mounting bracket 810 via the tilt adjustment component and the height adjustment component, the second vision component 100b is mounted on the second mounting bracket 820 via the tilt adjustment component and the height adjustment component, and the third vision component 100c is mounted on the second mounting bracket 820 via the tilt adjustment component and the height adjustment component. By setting up tilt adjustment components and height adjustment components, the imaging light between the first inclined surface 141 of the beam splitter 140 and the first wafer W1 can be made perpendicular to the first wafer W1 by adjusting the tilt angle and height position of the vision component 100. At the same time, the imaging light between the second inclined surface 142 of the beam splitter 140 and the second wafer W2 can be made perpendicular to the second wafer W2. Furthermore, both the first wafer W1 and the second wafer W2 are located on the image acquisition focal plane of the vision component 100, thereby obtaining a higher quality image to be processed.

[0145] In some embodiments, step S140, which controls the adjustment component 500 to move the second carrier 400 according to the offset information so that the second wafer W2 is aligned with the first wafer W1, includes the following steps: controlling the adjustment component 500 to move the second carrier 400 along the first horizontal direction X by a first horizontal offset N1; controlling the adjustment component 500 to move the second carrier 400 along the second horizontal direction Y by a second horizontal offset N2, wherein the second horizontal direction Y is orthogonal to the first horizontal direction X; and controlling the adjustment component 500 to rotate the second carrier 400 by an angle offset U.

[0146] In some embodiments, after the adjustment component 500 is controlled to move the second carrier 400 according to the offset information, multiple corresponding images to be processed can be acquired again through multiple vision components 100, and the offset information of the second wafer W2 relative to the first wafer W1 can be obtained again based on the multiple images to be processed. If the offset information meets the accuracy requirements, it is determined that the second wafer W2 and the first wafer W1 are aligned. If the offset information does not meet the accuracy requirements, the adjustment component 500 can be controlled to move the second carrier 400 again based on the offset information until the offset information meets the accuracy requirements.

[0147] This application also provides a wafer bonding system, which includes a wafer alignment device of any of the foregoing embodiments. Before bonding the second wafer W2 to the first wafer W1, the wafer bonding system aligns the second wafer W2 to the first wafer W1 using the wafer alignment device.

[0148] The wafer alignment apparatus includes a base 200, a first support 300, a second support 400, an adjustment assembly 500, at least two vision components 100 of any of the foregoing embodiments, and a control unit 600.

[0149] A first support member 300 is mounted on a base 200 and is used to support a first wafer W1. A second support member 400 is longitudinally spaced from the first support member 300 and is used to support a second wafer W2. An adjustment assembly 500 is mounted on the base 200 and connected to the second support member 400. The adjustment assembly 500 is used to move the second support member 400 relative to the first support member 300.

[0150] Each vision component 100 includes a camera 110, a light source 120, a semi-transparent beam splitter 130, and a beam splitter 140, arranged sequentially along a preset axis L1. The light source 120 is located on one side of the preset axis L1, with its light-emitting surface facing the semi-transparent beam splitter 130. The emitted light from the light source 120 can be reflected by the semi-transparent beam splitter 130 and projected onto the beam splitter 140. The beam splitter 140 extends between a first wafer W1 and a second wafer W2 placed opposite each other. The beam splitter 140 includes a first inclined surface 141 inclined towards the first wafer and a second inclined surface 142 inclined towards the second wafer, symmetrically arranged. The camera 110 is used to acquire an image to be processed, which includes images of the first wafer and the second wafer.

[0151] At least two vision components 100 are distributed around the second carrier 400. With the first carrier 300 carrying the first wafer W1 and the second carrier 400 carrying the second wafer W2, the beam splitter 140 of each vision component 100 is positioned laterally at the edge of the first wafer W1 and longitudinally between the first wafer W1 and the second wafer W2. Each vision component 100 is used to acquire a corresponding image to be processed. The image to be processed includes images of portions of the edges of the first wafer W1 and portions of the edges of the second wafer W2.

[0152] The control unit 600 is communicatively connected to the vision component 100 and the adjustment component 500. The control unit 600 is used to obtain offset information of the second wafer W2 relative to the first wafer W1 based on at least two images to be processed acquired by the multiple vision components 100. The control unit 600 obtains the offset information of the second wafer W2 relative to the first wafer W1 using the offset information calculation method of any of the aforementioned embodiments. The control unit 600 is used to control the adjustment component 500 to move the second carrier 400 according to the offset information, so that the second wafer W2 is aligned with the first wafer W1.

[0153] The wafer bonding system according to an embodiment of this application includes a wafer alignment device from any of the preceding embodiments. Before bonding the second wafer W2 to the first wafer W1, the wafer bonding system aligns the second wafer W2 to the first wafer W1 using the wafer alignment device. The wafer alignment device includes a first carrier 300, a second carrier 400, an adjustment component 500, at least two vision components 100, and a control unit 600. The first carrier 300 is used to carry the first wafer W1, and the second carrier 400 is used to carry the second wafer W2. Each vision component 100 includes a camera 110, a light source 120, a semi-transparent beam splitter 130, and a beam splitter prism 140. The beam splitter prism 140 can extend between the opposing first wafer W1 and second wafer W2. The beam splitter prism 140 includes a first inclined surface 141 tilted towards the first wafer W1 and a second inclined surface 142 tilted towards the second wafer W2, and the first inclined surface 141 and the second inclined surface 142 are symmetrically arranged. Each vision component 100 has a beam splitter 140 positioned laterally at the edge of the first wafer W1 and longitudinally between the first wafer W1 and the second wafer W2. Each vision component 100 is used to acquire a corresponding image to be processed. The camera 110 acquires the image to be processed via the beam splitter 140. The image to be processed includes images of a portion of the edge of the first wafer W1 and a portion of the edge of the second wafer W2. In this embodiment, at each image acquisition location, a single set of vision components 100 can simultaneously acquire images of a portion of the edge of the first wafer W1 and a portion of the edge of the second wafer W2. By replacing two sets of vision components in a traditional wafer alignment device with a single set of vision components 100, edge images of the first wafer W1 and the second wafer W2 can be acquired, thereby reducing the cost of the wafer alignment device and significantly improving image acquisition efficiency. The control unit 600 can obtain the offset information of the second wafer W2 relative to the first wafer W1. The control unit 600 can control the adjustment component 500 to drive the second carrier 400 to move according to the offset information, so that the second wafer W2 is aligned with the first wafer W1, thereby realizing the operation of aligning the second wafer W2 with the first wafer W1.

[0154] This application also provides a control unit. Figure 23 This is a schematic diagram of the hardware structure of one embodiment of the control unit according to this application. The control unit includes a memory 610, a processor 620, and a computer program stored in the memory 610 and running on the processor 620. When the processor executes the program, it implements the offset information calculation method according to any of the foregoing embodiments of this application. The memory 610 and the processor 620 are electrically connected.

[0155] Specifically, the processor 620 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0156] Memory 610 may include a large-capacity storage device for data or instructions. For example, and not limitingly, memory 610 may include a hard disk drive (HDD), a floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or a Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 610 may include removable or non-removable (or fixed) media. Where appropriate, memory 610 may be internal or external to the integrated gateway disaster recovery device. In a particular embodiment, memory 610 is a non-volatile solid-state memory. In a particular embodiment, memory 610 includes read-only memory (ROM). Where appropriate, the ROM may be a mask-programmed ROM, a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), an electrically rewritable ROM (EAROM), or flash memory, or a combination of two or more of these.

[0157] In one example, the control device may also include a communication interface 630 and a bus 640. The processor 620, memory 610, and communication interface 630 are connected via the bus 640 and communicate with each other.

[0158] The communication interface 630 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0159] Bus 640 includes hardware, software, or both, that couples components of an online data traffic metering device together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a Memory 610 bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 640 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, any suitable bus or interconnect is contemplated herein.

[0160] Furthermore, in conjunction with the offset information calculation method in the above embodiments, this application embodiment can provide a computer-readable storage medium for implementation. This computer-readable storage medium stores a computer program / instructions, which, when executed by a processor, implement the offset information calculation method according to any of the foregoing embodiments of this application.

[0161] This application also provides a computer program product, which includes a computer program / instructions that, when executed by a processor, implement the steps of the offset information calculation method according to any of the foregoing embodiments of this application.

[0162] This application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0163] The functional blocks shown in the above block diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0164] It should be noted that the technical solutions or features described in the above embodiments can be combined or supplemented with each other without conflict. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the accompanying drawings; all modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method of calculating offset information, characterized by, The method comprises: acquiring a first to-be-processed image and at least one second to-be-processed image collected by a vision component between relatively placed first and second wafers, the first to-be-processed image comprising images of a first notch of an edge of the first wafer and a second notch of an edge of the second wafer, and the second to-be-processed image comprising images of part of the edge of the first wafer and part of the edge of the second wafer, the first notch and the second notch being symmetrical patterns; processing the first to-be-processed image to obtain first distance information and an angle offset, comprising: determining a first boundary line in the first to-be-processed image, and identifying a first contour line and a second contour line on two sides of the first boundary line in the first to-be-processed image, the first contour line and the second contour line corresponding to the edge of the first wafer and the edge of the second wafer respectively, determining the first distance information and the angle offset based on a first tangent line at a symmetrical point of a notch in the first contour line and a second tangent line at a symmetrical point of a notch in a mirror line of the second contour line; processing the second to-be-processed image to obtain second distance information, the first distance information and the second distance information representing offset pixel values of the second wafer relative to the first wafer in the corresponding to-be-processed image respectively; performing fitting calculation on the first distance information and the second distance information to obtain a first lateral offset and a second lateral offset of the second wafer relative to the first wafer, and taking the first lateral offset, the second lateral offset, and the angle offset as the offset information.

2. The offset information calculation method according to claim 1, characterized by, A line connecting the acquisition positions of any two to-be-processed images does not pass through the center of the first wafer.

3. The offset information calculation method according to claim 1, characterized by, The determining of the first boundary line in the first to-be-processed image comprises: obtaining boundary line information of the vision component, the boundary line information being position information of a boundary line between two sub-images in the to-be-processed image acquired by the vision component; determining the first boundary line in the first to-be-processed image based on the boundary line information of the vision component acquiring the first to-be-processed image.

4. The offset information calculation method according to claim 1, characterized by, Before the determining of the first distance information and the angle offset based on the first tangent line at the symmetrical point of the notch in the first contour line and the second tangent line at the symmetrical point of the notch in the mirror line of the second contour line, the processing of the first to-be-processed image to obtain the first distance information and the angle offset further comprises: constructing a first mirror line, the first mirror line being symmetrical to the second contour line about the first boundary line, the first mirror line having a third notch corresponding to a mirror image of the second notch on the second contour line; obtaining the first tangent line at the symmetrical point of the first notch in the first contour line, and obtaining the second tangent line at the symmetrical point of the third notch in the first mirror line.

5. The offset information calculation method according to claim 4, characterized by, The determining of the first distance information and the angle offset based on the first tangent line at the symmetrical point of the notch in the first contour line and the second tangent line at the symmetrical point of the notch in the mirror line of the second contour line comprises: constructing a first reference line, the first reference line being perpendicular to the first boundary line and dividing the first to-be-processed image in half; acquire a first intersection point of the first tangent line and the first reference line, acquire a second intersection point of the second tangent line and the first reference line, and take a distance between the first intersection point and the second intersection point as the first distance information; obtain the angle offset according to an included angle between the first tangent line and the second tangent line.

6. The offset information calculation method of claim 3, wherein The processing of the second to-be-processed image to obtain second distance information includes: determining a second boundary line in the second to-be-processed image based on boundary line information of a vision component that collects the second to-be-processed image; performing feature recognition in the second to-be-processed image to obtain a third contour line and a fourth contour line located on two sides of the second boundary line, the third contour line corresponding to a partial edge of the first wafer, and the fourth contour line corresponding to a partial edge of the second wafer; constructing a second mirror line and a second reference line, the second mirror line being axially symmetrical to the fourth contour line about the second boundary line, and the second reference line being parallel to the second boundary line and intersecting the third contour line and the second mirror line; acquiring a third intersection point of the third contour line and the second reference line, acquiring a fourth intersection point of the second mirror line and the second reference line, and taking a distance between the third intersection point and the fourth intersection point as the second distance information.

7. The offset information calculation method of claim 1, wherein The fitting calculation of the first distance information and the second distance information to obtain the first lateral offset and the second lateral offset of the second wafer relative to the first wafer includes: obtaining resolution calibration information and coordinate axis calibration information corresponding to the vision component, wherein the resolution calibration information is a mapping relationship between a size of a single pixel in the to-be-processed image obtained by the vision component and an actual physical size, and the coordinate axis calibration information is a mapping relationship between a rectangular coordinate axis in the to-be-processed image obtained by the vision component and a first lateral direction and a second lateral direction, the first lateral direction and the second lateral direction being orthogonal in a plane parallel to the first wafer; fitting to obtain the first lateral offset and the second lateral offset according to the first distance information, the second distance information, the resolution calibration information, and the coordinate axis calibration information.

8. The offset information calculation method according to claim 7, characterized by, The method further includes: obtaining a third to-be-processed image collected by the vision component and processing the third to-be-processed image to obtain third distance information, the third to-be-processed image including an image of a partial first wafer edge and an image of a partial second wafer edge; fitting to obtain the first lateral offset and the second lateral offset according to the first distance information, the second distance information, the third distance information, the resolution calibration information, and the coordinate axis calibration information. The vision component includes a camera, a light source, a semi-transparent beam splitter, and a beam splitting prism, the camera, the semi-transparent beam splitter, and the beam splitting prism being arranged along a preset axis in sequence, 9. The offset information calculation method according to claim 3, characterized by, ​ The light source is located on one side of the preset axis, and an outlight surface of the light source faces the semi-transparent beam splitter, and the light emitted by the light source can be projected to the beam splitter and then to the beam splitter prism, The beam splitter prism can be extended to between the first wafer and the second wafer, and the beam splitter prism comprises a first inclined surface inclined towards the first wafer and a second inclined surface inclined towards the second wafer, and the first inclined surface and the second inclined surface are symmetrically arranged, The camera is used to acquire a to-be-processed image, and the to-be-processed image comprises an image of the first wafer and an image of the second wafer.

10. The offset information calculation method according to claim 9, characterized by, The boundary line information of the vision component is acquired, comprising: A calibration image of a calibration block installed on the beam splitter prism is acquired by the vision component, the calibration block comprises a first calibration part and a second calibration part symmetrically arranged, and the first calibration part and the second calibration part are located on the image acquisition focal plane corresponding to the vision component; The boundary line information corresponding to the vision component is obtained according to the calibration image.

Images