Two-way alignment calibration device, method and two-way alignment apparatus

Abstract

This application provides a bidirectional alignment calibration device, method, and bidirectional alignment equipment. When the first spectral confocal system forms a first angle with the optical symmetry axis, the first spectral confocal system is translated a fixed distance relative to the marker plate along the optical symmetry axis for the first time. The difference between the first distance and the second distance corresponding to the first spectral confocal system before and after the first translation is obtained. After rotating the marker plate around a first vertical direction, such as the z-axis, by a set angle, the first spectral confocal system is translated a fixed distance relative to the marker plate along the optical symmetry axis for the second time. The difference between the third distance and the fourth distance corresponding to the first spectral confocal system before and after the second translation is obtained. The first angle is obtained by solving the first and second sine relationships of the two translations, ultimately achieving coaxiality of the bidirectional spectral confocal system. Simultaneously, the overlapping working distances of the bidirectional imaging alignment system and the bidirectional spectral confocal system are measured and calibrated, improving reliability.

Description

Technical Field

[0001] This application relates to the field of precision machining technology, specifically to a bidirectional alignment calibration device, method, and bidirectional alignment equipment. Background Technology

[0002] With the standardization and industrialization of processing and assembly in manufacturing, achieving precise alignment between components requires the assistance of various measurement sensors. In many applications, the need for bidirectional alignment devices that achieve six-axis (e.g., X, Y, Z, RX, RY, RZ) alignment between components is very widespread, such as in the assembly of precision devices, the adjustment of optical components, and precision control equipment in the semiconductor industry. The calibration accuracy of the bidirectional alignment device determines the alignment accuracy of the equipment's control components; therefore, achieving high-precision calibration of the bidirectional alignment device is particularly crucial.

[0003] Bidirectional alignment devices typically incorporate a dual-spectral confocal system for leveling and a dual-image recognition alignment system for horizontal and vertical rotational alignment. While traditional bidirectional alignment devices can achieve leveling and alignment, when the measured plate is tilted, the calibrated bidirectional confocal system also tilts, leading to complex and inconvenient adjustments. Finding the correct alignment requires repeated adjustments, and the lack of a clear direction and adjustment amount makes the calibration process cumbersome.

[0004] Therefore, a bidirectional alignment device and its calibration scheme are needed. Summary of the Invention

[0005] In view of this, embodiments of this specification provide a bidirectional alignment calibration device, method, and bidirectional alignment equipment.

[0006] The embodiments in this specification provide the following technical solutions:

[0007] This specification provides an embodiment of a bidirectional alignment calibration device, comprising:

[0008] The system comprises a first spectral confocal system, a second spectral confocal system, a first imaging alignment system, a second imaging alignment system, a marker plate, a detector, and a bidirectional alignment module.

[0009] The first spectral confocal system and the second spectral confocal system are respectively located on both sides of the bidirectional alignment module;

[0010] The first imaging alignment system and the second imaging alignment system are respectively separated from the first spectral confocal system by a preset distance along the optical symmetry axis of the bidirectional alignment module and are also respectively set on both sides of the bidirectional alignment module.

[0011] The marking plate is disposed on at least one side of the bidirectional alignment module; the marking plate is provided with coaxial alignment marks and working distance alignment marks;

[0012] The first spectral confocal system forms a first plane with the optical symmetry axis, and there exists a first vertical direction perpendicular to the first plane;

[0013] The first vertical direction forms a second plane with the optical axis of symmetry, and there exists a second vertical direction perpendicular to the second plane;

[0014] Specifically, when the first spectral confocal system forms a first angle with the optical symmetry axis, the first spectral confocal system is translated a fixed distance relative to the marker plate along the optical symmetry axis for the first time. The first distance obtained by the first spectral confocal system on the marker plate before the first translation and the second distance obtained by the first spectral confocal system on the marker plate after the first translation are obtained, and the difference between the first distance and the second distance is obtained.

[0015] The first sine relationship is formed based on the first included angle, the second included angle between the marking plate and the optical symmetry direction, the fixed distance, and the difference between the first distance and the second distance;

[0016] After rotating the marker plate around the first vertical direction by a set angle, the first spectral confocal system is translated a fixed distance relative to the marker plate along the optical symmetry axis. The third distance obtained by the first spectral confocal system on the marker plate before the second translation and the fourth distance obtained by the first spectral confocal system on the marker plate after the second translation are obtained. The difference between the third distance and the fourth distance is then obtained.

[0017] The second sine relationship is formed based on the first included angle, the second included angle between the marking plate and the optical axis of symmetry, the fixed distance, the set angle, and the difference between the third and fourth distances;

[0018] Based on the first and second sinusoidal relationships, the first spectral confocal system forms a first angle with the optical axis of symmetry, and the second angle forms between the marking plate and the optical axis of symmetry. The first spectral confocal system is then adjusted to be perpendicular to the optical axis of symmetry, and the marking plate is adjusted to be parallel to the optical axis of symmetry.

[0019] The first spectral confocal system is determined to be perpendicular to the first vertical direction, and the marker plate is also perpendicular to the first vertical direction. When the first spectral confocal system is determined to be parallel to the second vertical direction, and the marker plate is also perpendicular to the second vertical direction, and the second spectral confocal system is parallel to the second vertical direction, the first and second spectral confocal systems are used respectively to image coaxially aligned markers of the same size on the marker plate. When the distance between the first and second spectral confocal systems and the marker plate are the same, and the spectral signal amplitudes are the same, the optical axes of the two spectral confocal systems are coaxial.

[0020] Keeping the marker plate stationary, determine the working distances of the first imaging alignment system and the second imaging alignment system to overlap with the working distances of the two spectral confocal systems, respectively.

[0021] This specification also provides a bidirectional alignment calibration method, including:

[0022] When the first spectral confocal system forms a first angle with the optical symmetry axis, the first spectral confocal system is translated a fixed distance relative to the marker plate along the optical symmetry axis for the first time. The first distance obtained by the first spectral confocal system on the marker plate before the first translation and the second distance obtained by the first spectral confocal system on the marker plate after the first translation are obtained. The difference between the first distance and the second distance is then obtained.

[0023] The first sine relationship is formed based on the first included angle, the second included angle between the marking plate and the optical axis of symmetry, the fixed distance, and the difference between the first distance and the second distance;

[0024] After rotating the marker plate around the first vertical direction by a set angle, the first spectral confocal system is translated a fixed distance relative to the marker plate along the optical symmetry axis. The third distance obtained by the first spectral confocal system on the marker plate before the second translation and the fourth distance obtained by the first spectral confocal system on the marker plate after the second translation are obtained. The difference between the third distance and the fourth distance is then obtained.

[0025] The second sine relationship is formed based on the first included angle, the second included angle between the marking plate and the optical axis of symmetry, the fixed distance, the set angle, and the difference between the third and fourth distances;

[0026] Based on the first and second sinusoidal relationships, the first spectral confocal system forms a first angle with the optical axis of symmetry, and the second angle forms between the marking plate and the optical axis of symmetry. The first spectral confocal system is then adjusted to be perpendicular to the optical axis of symmetry, and the marking plate is adjusted to be parallel to the optical axis of symmetry.

[0027] The first spectral confocal system is determined to be perpendicular to the first vertical direction, and the marker plate is also perpendicular to the first vertical direction. When the first spectral confocal system is determined to be parallel to the second vertical direction, and the marker plate is also perpendicular to the second vertical direction, and the second spectral confocal system is parallel to the second vertical direction, and the marker plate is fixed, the first spectral confocal system and the second spectral confocal system are used respectively to image a coaxially aligned marker of the same size on the marker plate. When the distance between the first spectral confocal system and the marker plate is the same as the distance between the second spectral confocal system and the marker plate, and the spectral signal amplitude is the same, the optical axes of the two spectral confocal systems are coaxial.

[0028] Keeping the marker plate stationary, determine the working distances of the first imaging alignment system and the second imaging alignment system to overlap with the working distances of the two spectral confocal systems, respectively.

[0029] Compared with the prior art, the beneficial effects that at least one technical solution adopted in the embodiments of this specification can achieve include at least:

[0030] This application obtains two corresponding first and second sine relationships by translating a fixed distance when a spectral confocal system forms different angles with the optical axis of symmetry. Solving for these angles yields the two corresponding relationships. Quantifying these angles allows for the measurement and calibration of the coaxiality of the bidirectional spectral confocal system in the bidirectional alignment device. Simultaneously, it measures and calibrates the overlap of the working distances of the bidirectional imaging alignment system and the bidirectional spectral confocal system, improving the reliability of the alignment equipment. This enables the constructed optical module to achieve online six-axis alignment in application scenarios, improving not only alignment accuracy but also operational convenience. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the spectral confocal system and imaging alignment system provided in the embodiments of this specification. Figure 1 ;

[0033] Figure 2 This is a schematic diagram illustrating the calculation of the tilt angle of the marker plate and the tilt angle of the spectral confocal system provided in the embodiments of this specification;

[0034] Figure 3 This is a schematic diagram of the vertical spectral confocal system provided in the embodiments of this specification;

[0035] Figure 4 This is a schematic diagram of the coaxial two-spectral confocal system provided in the embodiments of this specification;

[0036] Figure 5 This is a schematic diagram of overlapping but non-axial dual-spectral confocal working distances provided in the embodiments of this specification;

[0037] Figure 6 This is a schematic diagram of the measurement and calibration of the working distance overlap between the imaging alignment system and the spectral confocal system provided in the embodiments of this specification;

[0038] Figure 7 This is a schematic diagram of the measurement and calibration of the working distance overlap between the dual imaging alignment system and the dual-spectral confocal system provided in the embodiments of this specification;

[0039] Figure 8 This is a schematic diagram of the dual-marker plate calibration provided in the embodiments of this specification. Detailed Implementation

[0040] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0041] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0042] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0043] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0044] Additionally, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that practice can be carried out without these specific details.

[0045] Traditional bidirectional alignment devices, such as the patent document with publication number CN111928788A, disclose a bidirectional through-beam spectral confocal plate thickness detection system and its dual optical axis calibration method. This primarily utilizes the light energy method to quantitatively adjust the system's parallelism and align the confocal probe's optical axis. While leveling and alignment can be achieved, the calibrated bidirectional through-beam spectral confocal system will also be tilted when the plate being measured is tilted. Furthermore, finding the position with the maximum light energy requires continuous adjustments, lacking a clear direction and amount of adjustment, making the calibration process cumbersome.

[0046] Based on this, the embodiments of this specification propose a new bidirectional alignment scheme: when the first spectral confocal system forms a first angle with the optical axis of symmetry, the first spectral confocal system is translated a fixed distance relative to the marker plate along the optical axis of symmetry for the first time, and the difference between the first distance and the second distance corresponding to the first distance is obtained before and after the first translation; after rotating the marker plate around a first vertical direction such as the z-axis by a set angle, the first spectral confocal system is translated a fixed distance relative to the marker plate along the optical axis of symmetry for the second time, and the difference between the third distance and the fourth distance corresponding to the first distance is obtained before and after the second translation; the first angle is obtained by solving the first sine relationship and the second sine relationship of the two translations, and finally the coaxiality of the bidirectional spectral confocal system is achieved, while the working distance overlap between the bidirectional imaging alignment system and the bidirectional spectral confocal system is measured and calibrated, thereby improving reliability.

[0047] The technical solutions provided by the various embodiments of this application are described below with reference to the accompanying drawings.

[0048] like Figure 1 As shown in the embodiments of this specification, a bidirectional alignment calibration device includes a first spectral confocal system 1, a second spectral confocal system 2, a first imaging alignment system 3, a second imaging alignment system 4, a marker plate 5, a detector (not shown), and a bidirectional alignment module 8. The marker plate 5 is provided with coaxial alignment marks 6 and working distance alignment marks 7.

[0049] The first spectral confocal system and the second spectral confocal system are respectively located on both sides of the bidirectional alignment module, such as on the upper and lower sides of the bidirectional alignment module.

[0050] The first imaging alignment system and the second imaging alignment system are respectively spaced at a preset distance from the first spectral confocal system along the optical symmetry axis of the bidirectional alignment module and are also respectively located on both sides of the bidirectional alignment module; for example, the first imaging alignment system and the second imaging alignment system are respectively located on the right side of the two spectral confocal systems and spaced at a preset distance from the two spectral confocal systems, and the first imaging alignment system and the second imaging alignment system are also respectively located on the upper and lower sides of the bidirectional alignment module.

[0051] The marking plate is located on the upper side of the bidirectional alignment module.

[0052] To facilitate bidirectional alignment and calibration, a coordinate system is established, with the optical symmetry axis as one dimension of the three-dimensional coordinate system. The first spectral confocal system and the optical symmetry axis form a first plane, and there exists a first vertical direction perpendicular to the first plane, which is also used as the other dimension of the three-dimensional coordinate system.

[0053] The first vertical direction forms a second plane with the optical symmetry axis, and there exists a second vertical direction perpendicular to the second plane, which is used as the coordinate of another directional dimension in the three-dimensional coordinate system.

[0054] Specifically, when the first spectral confocal system forms a first angle with the optical symmetry axis, the first spectral confocal system is translated a fixed distance relative to the marker plate along the optical symmetry axis for the first time. The first distance obtained by the first spectral confocal system on the marker plate before the first translation and the second distance obtained by the first spectral confocal system on the marker plate after the first translation are obtained, and the difference between the first distance and the second distance is obtained.

[0055] The first sine relationship is formed based on the first included angle, the second included angle between the marking plate and the optical symmetry direction, the fixed distance, and the difference between the first distance and the second distance;

[0056] After rotating the marker plate around the first vertical direction by a set angle, i.e. when the first spectral confocal system forms a third angle with the optical symmetry axis, the first spectral confocal system is translated a fixed distance relative to the marker plate along the optical symmetry axis. The third distance obtained by the first spectral confocal system on the marker plate before the second translation and the fourth distance obtained by the first spectral confocal system on the marker plate after the second translation are obtained. The difference between the third distance and the fourth distance is then obtained.

[0057] The second sine relationship is formed based on the first included angle, the second included angle between the marking plate and the optical axis of symmetry, the fixed distance, the set angle, and the difference between the third and fourth distances;

[0058] Based on the first and second sinusoidal relationships, the first spectral confocal system forms a first angle with the optical axis of symmetry, and the second angle forms between the marking plate and the optical axis of symmetry. The first spectral confocal system is then adjusted to be perpendicular to the optical axis of symmetry, and the marking plate is adjusted to be parallel to the optical axis of symmetry.

[0059] When the first spectral confocal system is determined to be perpendicular to the first vertical axis, and the marker plate is also determined to be perpendicular to the first vertical axis; when the first spectral confocal system is determined to be parallel to the second vertical axis, and the marker plate is also determined to be perpendicular to the second vertical axis, the coordinate axes in the three-dimensional coordinate system are determined to be mutually perpendicular. Furthermore, the second spectral confocal system is parallel to the second vertical axis. When the first and second spectral confocal systems are used to image a coaxially aligned marker of the same size on the marker plate, and the distance between the first and second spectral confocal systems and the marker plate is the same, and the spectral signal amplitude is the same, the optical axes of the two spectral confocal systems are coaxial.

[0060] Keeping the marker plate stationary, determine the working distances of the first imaging alignment system and the second imaging alignment system to overlap with the working distances of the two spectral confocal systems, respectively.

[0061] This application can measure and calibrate the coaxiality of the bidirectional spectral confocal system in a bidirectional alignment device, and simultaneously measure and calibrate the working distance overlap between the bidirectional imaging alignment system and the bidirectional spectral confocal system, thereby improving the reliability of the alignment equipment. This enables the constructed optical module to achieve online six-axis alignment in application scenarios, improving alignment accuracy.

[0062] This application can directly calculate the tilt of the marker plate and the tilt of the spectral confocal optical axis by measuring the values ​​before and after rotating the marker plate. This quantifies the adjustment of the tilt and avoids the working distance of the dual-spectral confocal system in the tilt state after calibration being the same due to the tilt of the marker plate. The dual-spectral confocal system can keep parallel to the movement direction of the displacement stage, which is beneficial for the measurement and adjustment of the target after calibration.

[0063] This application simultaneously achieves the goal of overlapping working distances for both the dual-spectral confocal system and the dual imaging alignment system.

[0064] In some embodiments, such as Figure 1 As shown, the first spectral confocal system, the second spectral confocal system, the first imaging alignment system, and the second imaging alignment system are all mounted on the same bidirectional alignment module.

[0065] In some embodiments, the bidirectional alignment module is positioned horizontally or vertically.

[0066] In some embodiments, the coaxial alignment mark is used for alignment of the spectral confocal system; the working distance alignment mark is used for alignment of the imaging alignment system.

[0067] Two marker plates are symmetrically arranged on both sides of the bidirectional alignment module, with the coaxial alignment mark and working distance alignment mark on each marker plate symmetrically arranged along the optical axis of symmetry.

[0068] like Figure 8 As shown, a coordinate system is established, and six degrees of freedom adjustment is achieved using two marker plates, one above the other. The first marker plate is shown as upper marker plate 51, and the second marker plate is shown as lower marker plate 52. Each marker plate carries coaxial alignment marks such as 61 and 62 corresponding to the spectral confocal alignment system, and working distance alignment marks such as 71 and 72 corresponding to the imaging alignment system. During the six-degree-of-freedom adjustment process, the projections of coaxial alignment marks 61 and 62 onto the plane formed by the optical axis of symmetry and the second vertical direction (e.g., the XZ plane) overlap. The projections of working distance alignment marks 71 and 72 onto the plane formed by the optical axis of symmetry and the second vertical direction (e.g., the XZ plane) also overlap, thus ensuring the coaxial alignment of the dual-spectral confocal system and the imaging lens.

[0069] In some embodiments, the marked area and the unmarked area on the marking plate form different reflection contrasts, and the marked area is used to enhance or reduce reflection; one of the marked area or the unmarked area in the marking plate is set as a chrome-plated reflective surface.

[0070] Specifically, the marked area and the unmarked area on the marking plate have a high contrast in reflection, and the marked area can have enhanced or reduced reflection. The marked area on the marking plate 5 can be a chrome-plated reflective surface, or the unmarked area can be a chrome-plated reflective surface.

[0071] In some embodiments, the bidirectional alignment module is disposed on a rotary table, the rotation axis of the rotary table coincides with the optical symmetry axis of the bidirectional alignment module, the optical symmetry axis is the X direction, the second vertical direction is the Y direction, and the first vertical direction is the Z direction.

[0072] like Figure 1 , 3 As shown in Figure -8, the optical axis of symmetry is the X direction, the second perpendicular direction is the Y direction, and the first perpendicular direction is the Z direction.

[0073] In some embodiments, the rotary table is a multidimensional rotary table, which is used to move the bidirectional alignment module to achieve ranging with the two-spectrum confocal system.

[0074] For example, the bidirectional alignment module 8 can be installed on a multidimensional rotating stage. During the process of measuring the distance between the marker plate 5 and the first spectral confocal point 1, the marker plate 5 can be fixed and the bidirectional alignment module 8 can be moved to achieve distance measurement at two positions.

[0075] This application uses rotation to enable the dual-spectrum confocal system and dual-imaging alignment system to calibrate the same mark, thus avoiding calibration errors introduced by the alignment mark plate.

[0076] In some embodiments, the first imaging alignment system and the second imaging alignment system share a single detector, which is an image sensor.

[0077] In conjunction with the above embodiments, this specification also provides a bidirectional alignment calibration method, including the following steps:

[0078] Step 1: When the first spectral confocal system forms a first angle with the optical axis of symmetry, the first spectral confocal system is translated a fixed distance relative to the marker plate along the optical axis of symmetry for the first time. The first distance obtained by the first spectral confocal system on the marker plate before the first translation and the second distance obtained by the first spectral confocal system on the marker plate after the first translation are obtained. The difference between the first distance and the second distance is then obtained.

[0079] Step 2: Based on the first included angle, the second included angle between the marking plate and the optical symmetry direction, the fixed distance, and the difference between the first distance and the second distance, a first sine relationship is formed.

[0080] Step 3: After rotating the marker plate around the first vertical direction by a set angle, that is, when the first spectral confocal system forms a third angle with the optical symmetry axis, the first spectral confocal system is translated a fixed distance relative to the marker plate along the optical symmetry axis for the second time. The third distance obtained by the first spectral confocal system on the marker plate before the second translation and the fourth distance obtained by the first spectral confocal system on the marker plate after the second translation are obtained. The difference between the third distance and the fourth distance is then obtained.

[0081] Step 4: Based on the first included angle, the second included angle between the marking plate and the optical axis of symmetry, the fixed distance, the set angle, and the difference between the third and fourth distances, a second sine relationship is formed.

[0082] Step 5: Based on the first sine relationship and the second sine relationship, obtain the first angle between the first spectral confocal system and the optical symmetry axis direction, and the second angle between the marking plate and the optical symmetry axis direction. Adjust the first spectral confocal system to be perpendicular to the optical symmetry axis direction and the marking plate to be parallel to the optical symmetry axis direction.

[0083] Step 6: Determine that the first spectral confocal system is perpendicular to the first vertical axis and the marker plate is perpendicular to the first vertical axis; determine that the first spectral confocal system is parallel to the second vertical axis and the marker plate is perpendicular to the second vertical axis, and that the second spectral confocal system is parallel to the second vertical axis. When the marker plate is fixed, use the first spectral confocal system and the second spectral confocal system to image a coaxially aligned marker of the same size on the marker plate. When the distance between the first spectral confocal system and the marker plate is the same as the distance between the second spectral confocal system and the marker plate, and the spectral signal amplitude is the same, the optical axes of the two spectral confocal systems are coaxial.

[0084] Step 7: Keep the marker plate stationary and determine the working distances of the first imaging alignment system and the second imaging alignment system to overlap with the working distances of the two spectral confocal systems, respectively.

[0085] Specifically, the calibration process for the first spectral confocal system and the second spectral common-focal system is similar; only the first spectral confocal system will be used as an example for illustration. For example... Figure 1 For example, the optical symmetry axis is the x-axis, the second perpendicular direction is the y-axis, and the first perpendicular direction is the z-axis, which is perpendicular to the xy-plane and extends outwards.

[0086] The first step is to turn on the first spectral confocal system when it forms a first angle α (unknown) with the direction of the optical symmetry axis, and measure the distance of the marker plate to obtain the first distance.

[0087] The second step is to translate the marker plate by a fixed distance L along the optical axis of symmetry, use the first spectral confocal system to measure the distance of the marker plate again to obtain the second distance, and calculate the difference Δ1 between the first distance and the second distance.

[0088] The third step involves determining the first included angle α, the second included angle β (unknown) between the marker plate and the optical axis of symmetry, the fixed distance L, and Δ1, as follows: Figure 2 The first sine relationship obtained as shown in the above section is as shown in Formula 1.

[0089]

[0090] The fourth step involves rotating the marker plate around the first vertical direction by a set angle θ, and then using the first spectral confocal system to measure the distance of the marker plate to obtain the third distance.

[0091] Fifth, continue to translate the marker plate a fixed distance L along the optical axis of symmetry, and use the first spectral confocal system to measure the distance of the marker plate to obtain the fourth distance, and calculate the difference Δ2 between the third and fourth distances, as follows. Figure 2 The second sine relationship, as shown in the following section, is obtained as shown in Formula 2.

[0092]

[0093] Step 6: Obtain the first included angle α and the second included angle β (i.e., the angle between the intersection of the marker plate and the XY plane and the x-axis direction) according to Formula 1 and Formula 2. Repeat the above adjustment and calculation to adjust the first spectral confocal system to be perpendicular to the optical symmetry axis direction and the marker plate to be parallel to the optical symmetry axis direction.

[0094] Similarly, calculate the angle between the intersection of the marker plate and the yz plane and the z-axis direction, and the angle between the first spectral confocal system and the z-axis direction.

[0095] Calculate the angle between the intersection of the marker plate and the xz plane and the y-axis, and the angle between the first spectral confocal system and the y-axis.

[0096] Ultimately, it is determined that at least the intersection of the marker plate and the xz plane is perpendicular to the y-axis, and the first spectral confocal system is parallel to the y-axis.

[0097] Similarly, a second spectral confocal system can be made parallel to the y-axis.

[0098] The marking plate contains markings of similar size to the spectral confocal spot, which enhance or reduce reflection for opposing dual-spectral confocal coaxial alignment.

[0099] like Figure 3 , Figure 4As shown, the optical symmetry axis is set on the rotary stage, and the rotation axis of the rotary stage coincides with the optical symmetry axis. In the seventh step, keeping the current marker plate stationary, rotate the rotary stage so that the first and second spectral confocal systems image the same small-sized alignment mark on the marker plate. When the measurement distances of the two spectral confocal systems are the same, and the spectral signal amplitudes are the same (i.e., the echo signal intensity remains consistent), the two spectral confocal systems achieve coaxiality, and the optical axis is parallel to the Y-axis (perpendicular to the rotation axis) during calibration. At this time, the opposing dual-spectral confocal systems are coaxial, and their axes are parallel to the Y-axis (i.e., perpendicular to the bidirectional alignment module).

[0100] Figure 5 This is a schematic diagram of a dual-spectrum confocal system where the optical axis is parallel to the Y-axis, but the amplitudes of the spectral signals are different. In this case, the dual-spectrum confocal system has not achieved coaxial calibration.

[0101] Step 8: Keep the marker plate stationary and determine the working distances of the first imaging alignment system and the second imaging alignment system to overlap with the working distances of the two spectral confocal systems, respectively.

[0102] like Figure 6 As shown, the position of the first imaging alignment system is adjusted so that the detector can form a clear image of the working distance alignment mark on the marker plate, thus completing the overlap measurement and calibration of the working distance of the first imaging alignment system and the working distance of the spectral confocal system.

[0103] Figure 7 The diagram shows a turntable rotating 180 degrees to adjust the position of the second imaging alignment system and perform imaging calibration on the same working distance alignment mark. When the image is clear and the image position overlaps with the position of the first imaging alignment system, the calibration is completed to make the working distance of the opposing dual imaging alignment system the same as that of the opposing dual-spectral confocal system.

[0104] In the method for coaxial calibration of the spectral confocal system and the method for overlapping calibration of the working distance between the spectral confocal system and the imaging alignment system provided in this application, after the calibration strips of the marker plate are paralleled by the first spectral confocal system, the marker plate can only be translated relative to the optical module along the rotation axis direction.

[0105] By rotating the central axis of the optical module on a turntable, the opposing dual-spectrum confocal system and imaging alignment system are used to measure distance and image a marker plate at the same position. This achieves coaxial adjustment of the dual-spectrum confocal system with its axis perpendicular to the rotation axis, while also calibrating the overlap of the working distances of the dual-spectrum confocal system and the imaging alignment system.

[0106] like Figure 8As shown, the angle and lateral coordinate position of the marker plate are adjusted, and the tilt angle of the marker plate and the tilt angle of the spectral confocal optical axis are calculated. Based on the tilt angle calculation results, the spectral confocal optical axis is adjusted to be parallel to the Y-axis, thereby achieving parallel optical axes of the dual-spectral confocal system. Then, by measuring the maximum signal position of the small marker through spectral confocal measurement, the horizontal position of the dual-spectral confocal optical axis is adjusted to achieve optical axis coincidence of the dual-spectral confocal system. At this time, the optical axis remains coincident with the Y-axis. Keeping the positions of marker plates 51 and 52 unchanged, the positions of lenses 3 and 4 are adjusted so that the optimal focal plane position of the alignment imaging system overlaps with the positions of marker plates 51 and 52, respectively, completing the calibration of the parallel optical axes of the bidirectional alignment imaging lenses. The horizontal position of the bidirectional alignment imaging lenses is adjusted so that markers 71 and 72 are located in the same position in the camera's field of view. This operation achieves optical axis coincidence of the two lenses in the alignment imaging system, and the optical axis is parallel to the dual-spectral confocal system. Because the positions of marker plates 51 and 52 remain unchanged after the adjustment of the dual-spectral confocal system, the working distance of the bidirectional alignment imaging lens overlaps with the working distance of the dual-spectral confocal system.

[0107] This application can measure and calibrate the coaxiality of the bidirectional spectral confocal system in a bidirectional alignment device, and simultaneously measure and calibrate the working distance overlap between the bidirectional imaging alignment system and the bidirectional spectral confocal system, thereby improving the reliability of the alignment equipment. This enables the constructed optical module to achieve online six-axis alignment in application scenarios, improving alignment accuracy.

[0108] In conjunction with the above embodiments, this application also provides a bidirectional alignment device, wherein after calibration, the first spectral confocal system and the second spectral confocal system are coaxial and arranged perpendicularly on both sides of the bidirectional alignment module. The first imaging alignment system and the second imaging alignment system are respectively arranged perpendicularly on both sides of the bidirectional alignment module and overlap with the working distance of the two spectral confocal systems, so as to rotate, align and level other devices on both sides of the bidirectional alignment device.

[0109] The same or similar parts between the various embodiments in this specification can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the product embodiments described later are relatively simple in description since they correspond to the methods, and relevant parts can be referred to the descriptions in the system embodiments.

[0110] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A two-way alignment calibration device, characterized by, The application relates to a two-way alignment module for a spectral confocal system. The first spectral confocal system and the second spectral confocal system are arranged on the two sides of the two-way alignment module. The first imaging alignment system and the second imaging alignment system are arranged on the two sides of the two-way alignment module and are spaced apart from the first spectral confocal system along the optical symmetry axis direction by a preset distance. The mark plate is arranged on at least one side of the two-way alignment module, and the mark plate is provided with coaxial alignment marks and working distance alignment marks. The first spectral confocal system and the optical symmetry axis form a first plane, and a first vertical direction perpendicular to the first plane exists. The first vertical direction and the optical symmetry axis form a second plane, and a second vertical direction perpendicular to the second plane exists. When the first spectral confocal system and the optical symmetry axis direction form a first included angle, the first spectral confocal system is first translated along the optical symmetry axis direction relative to the mark plate by a fixed distance, the first distance obtained by the first spectral confocal system on the mark plate before the first translation is obtained, the second distance obtained by the first spectral confocal system on the mark plate after the first translation is obtained, and the difference between the first distance and the second distance is obtained. The first included angle, the second included angle between the mark plate and the optical symmetry axis direction, the fixed distance and the difference between the first distance and the second distance form a first sine relationship. After the mark plate is rotated around the first vertical direction by a set angle, the first spectral confocal system is second translated along the optical symmetry axis direction relative to the mark plate by the fixed distance, the third distance obtained by the first spectral confocal system on the mark plate before the second translation is obtained, the fourth distance obtained by the first spectral confocal system on the mark plate after the second translation is obtained, and the difference between the third distance and the fourth distance is obtained. ; wherein a is a first angle, β is a second angle of the marker plate and the optical symmetry direction, L is a fixed distance, and Δ1 is a difference between the first distance and the second distance. The second included angle between the mark plate and the optical symmetry axis direction, the fixed distance, the set angle and the difference between the third distance and the fourth distance form a second sine relationship. The first spectral confocal system and the optical symmetry axis direction form the first included angle, the second included angle between the mark plate and the optical symmetry axis direction is obtained according to the first sine relationship and the second sine relationship, and the first spectral confocal system is adjusted to be perpendicular to the optical symmetry axis direction and the mark plate is adjusted to be parallel to the optical symmetry axis direction. ; wherein a is a first angle, β is a second angle of the marker plate to the optical symmetry direction, θ is an angle of the marker plate rotating around the first vertical direction, L is a fixed distance, and Δ2 is a difference between a third distance and a fourth distance. When the first spectral confocal system is perpendicular to the first vertical direction and the mark plate is perpendicular to the first vertical direction, the first spectral confocal system is parallel to the second vertical direction and the mark plate is perpendicular to the second vertical direction, and the second spectral confocal system is parallel to the second vertical direction, the same size coaxial alignment marks on the mark plate are imaged by the first spectral confocal system and the second spectral confocal system respectively, the distance between the first spectral confocal system and the mark plate is the same as the distance between the second spectral confocal system and the mark plate, the spectral signal amplitude is the same, and the optical axes of the two spectral confocal systems are coaxial. The working distance of the first imaging alignment system and the working distance of the second imaging alignment system are overlapped with the working distance of the two spectral confocal systems. ​ 2. The bidirectionally aligned proofing device of claim 1, wherein, The first spectral confocal system, the second spectral confocal system, the first imaging alignment system and the second imaging alignment system are mounted on the same bidirectional alignment module; The bidirectional alignment module is horizontally placed or vertically placed.

3. The bi-directionally aligned proofing device of claim 1, wherein, The coaxial alignment mark is used for alignment of the spectral confocal system, and the working distance alignment mark is used for alignment of the imaging alignment system; Two mark plates are symmetrically arranged on two sides of the bidirectional alignment module, and the coaxial alignment marks and the working distance alignment marks on each mark plate are symmetrically arranged along the optical symmetry axis.

4. The bidirectionally aligned proofing device of claim 1, wherein, The mark area and the non-mark area on the mark plate form different reflection contrasts, and the mark area is used for reflection enhancement or reflection weakening. One of the mark area and the non-mark area in the mark plate is arranged as a chrome-plated reflective surface.

5. The bidirectionally aligned proofing device of claim 1, wherein, The bidirectional alignment module is arranged on a rotary table, the rotation axis of the rotary table coincides with the optical symmetry axis of the bidirectional alignment module, the rotation axis is in the X direction, the second vertical direction is in the Y direction, and the first vertical direction is in the Z direction.

6. The bidirectionally aligned proofing device of claim 5, wherein, The rotary table is a multi-dimensional rotary table, and the bidirectional alignment module is moved by the multi-dimensional rotary table to realize distance measurement with the two spectral confocal systems.

7. The bidirectionally aligned proofing device of claim 1, wherein, The first imaging alignment system and the second imaging alignment system share one detector, and the detector is an image sensor.

8. A method of bi-directional alignment calibration, characterized by, The device comprises a bidirectional alignment device according to any one of claims 1-7, and further comprises: When the first spectral confocal system is at a first included angle with the optical symmetry axis, the first spectral confocal system is first translated relative to the mark plate along the optical symmetry axis by a fixed distance, a first distance obtained by distance measurement of the first spectral confocal system on the mark plate before the first translation is obtained, a second distance obtained by distance measurement of the first spectral confocal system on the mark plate after the first translation is obtained, and a difference between the first distance and the second distance is obtained; The first included angle, a second included angle between the mark plate and the optical symmetry axis, the fixed distance and the difference between the first distance and the second distance form a first sine relationship; the formula of the first sine relationship is: ; wherein a is a first angle, β is a second angle of the marker plate with respect to an optical symmetry direction, L is a fixed distance, and Δ1 is a difference between the first distance and the second distance. After the mark plate is rotated around the first vertical direction by a set angle, the first spectral confocal system is second translated relative to the mark plate along the optical symmetry axis by the fixed distance, a third distance obtained by distance measurement of the first spectral confocal system on the mark plate before the second translation is obtained, a fourth distance obtained by distance measurement of the first spectral confocal system on the mark plate after the second translation is obtained, and a difference between the third distance and the fourth distance is obtained; The first included angle, the second included angle between the mark plate and the optical symmetry axis, the fixed distance, the set angle and the difference between the third distance and the fourth distance form a second sine relationship; the formula of the second sine relationship is: ; wherein a is a first angle, β is a second angle of the marker plate to the optical symmetry direction, θ is an angle of the marker plate rotating around the first vertical direction, L is a fixed distance, and Δ2 is a difference between a third distance and a fourth distance. The first spectral confocal system is at the first included angle with the optical symmetry axis, the second included angle between the mark plate and the optical symmetry axis is obtained according to the first sine relationship and the second sine relationship, and the first spectral confocal system is adjusted to be perpendicular to the optical symmetry axis and the mark plate is adjusted to be parallel to the optical symmetry axis. The first spectral confocal system is determined to be perpendicular to the first vertical direction, and the mark plate is determined to be perpendicular to the first vertical direction. When the first spectral confocal system is determined to be parallel to the second vertical direction, and the mark plate is determined to be perpendicular to the second vertical direction, and the second spectral confocal system is determined to be parallel to the second vertical direction, and the mark plate is determined to be fixed, the first spectral confocal system and the second spectral confocal system are respectively used to image the coaxial alignment marks of the same size on the mark plate. The distance between the first spectral confocal system and the mark plate is determined to be the same as the distance between the second spectral confocal system and the mark plate, and the spectral signal amplitude is determined to be the same. The optical axes of the two spectral confocal systems are coaxial. The mark plate is kept stationary, and the working distance of the first imaging alignment system and the working distance of the second imaging alignment system are determined to overlap the working distance of the two spectral confocal systems.

9. The method of bi-directional alignment calibration of claim 8, wherein, For the same working distance alignment marks, when the imaging is clear and the imaging positions overlap the positions of the first imaging alignment system or the second imaging alignment system, respectively, it is determined that the working distances of the two imaging alignment systems are the same as the working distance of the bidirectional spectral confocal system.

10. A bi-directional alignment apparatus, characterized by, The bidirectional alignment calibration device of any one of claims 1-7 is applied, and the bidirectional alignment calibration method of claim 8 or 9 is applied. The first spectral confocal system and the second spectral confocal system are coaxial, and are arranged on opposite sides of the bidirectional alignment module. The first imaging alignment system and the second imaging alignment system are respectively arranged on opposite sides of the bidirectional alignment module, and overlap the working distances of the two spectral confocal systems, so as to perform rotational alignment and leveling on other equipment on both sides of the bidirectional alignment device.

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