Back alignment method and device for double-sided exposure and exposure equipment

Abstract

The invention relates to a back alignment method and device for double-sided exposure and exposure equipment, which can realize high-precision double-sided alignment of plates with different specifications, and comprises the following steps: when the A surface of a plate is exposed, acquiring the front actual coordinate of a mark point on the A surface and the back actual coordinate of a target on the B surface; the exposure on the A surface is completed and the plate is turned over; the back face actual coordinates of the mark points collected by the back face alignment assembly and the front face actual coordinates of the target points collected by the front face alignment assembly are obtained; calculating back theoretical coordinates of the mark points and front theoretical coordinates of the target spots according to the plate size, the plate turning mode, the front actual coordinates of the mark points and the back actual coordinates of the target spots, and calculating the back theoretical coordinates of the mark points and the front theoretical coordinates of the target spots according to the back actual coordinates of the mark points and the back theoretical coordinates of the mark points; and performing alignment compensation on the front actual coordinate of the target spot and the front theoretical coordinate of the target spot, so that the A-side photoetching pattern is aligned with the B-side photoetching pattern.

Description

Technical Field

[0001] This application relates to the field of exposure technology, and in particular to a method, apparatus and exposure equipment for back-side alignment in double-sided exposure. Background Technology

[0002] When processing PCBs or semiconductor boards on both sides, it is necessary to align the two sides first to ensure that the patterns on the front and back layers match during double-sided exposure. Currently, a three-point alignment method is commonly used for alignment. However, with the improvement of board processing precision, the alignment accuracy of three-point alignment can no longer meet the alignment requirements of board exposure. Therefore, with technological advancements, techniques have emerged to increase the number of alignment points to further improve alignment accuracy.

[0003] However, significantly improving alignment accuracy by adding new alignment points remains a challenging problem. Existing alignment point marking devices are integrated into the suction cup and fixed on both sides where the suction cups intersect. These devices can mark three alignment points. However, when the number of alignment points increases to four, adding a fourth point along the line connecting the three points in the traditional three-point alignment method still results in the same error as with three-point alignment: it only identifies a triangular plane, not a quadrilateral plane, and cannot definitively determine whether the board has tilted or deformed, leading to low alignment accuracy. Furthermore, setting the alignment point to a quadrilateral presents challenges with the increasing demand for different board sizes and specifications. On suction cups capable of accommodating multiple board sizes, obtaining the fourth mark using multiple fixed marking devices is difficult. (See attached image) Figure 1 As shown, there are two boards of different specifications, namely board a and board b. The alignment marks 3 on the lower left, upper left and lower right corners of board a and board b can be obtained by marking 2 by the marking device integrated in suction cup 1 and located on the left and lower side of suction cup 1. However, the mark on the upper right corner of board a and board b is significantly different and cannot be obtained by marking with the marking device on the same axis. Summary of the Invention

[0004] Therefore, it is necessary to provide a back-side alignment method, apparatus, and exposure equipment with high alignment accuracy for double-sided exposure that can adapt to various specifications of sheet materials, in order to address the above-mentioned technical problems.

[0005] In a first aspect, this application provides a back-side alignment method for double-sided exposure, the method comprising:

[0006] When performing exposure on the A side of the substrate, the actual front coordinates of 1 or n markers at predetermined positions on the A side and the actual back coordinates of m targets on the B side are obtained; the line connecting the targets and the markers on the horizontal plane forms a convex quadrilateral arrangement, and the n markers are arranged with the row direction or column direction as the reference line.

[0007] After the exposure of side A is completed and the plate is flipped, obtain the actual coordinates of the back of the marked point collected by the back-side aligned component and the actual coordinates of the front of the target point collected by the front-side aligned component.

[0008] Obtain the board specifications and flipping method; calculate the theoretical coordinates of the back side of the marker point based on the board specifications, flipping method, and the actual front coordinates of the marker point; calculate the theoretical front coordinates of the target point based on the board specifications, flipping method, and the actual back coordinates of the target point.

[0009] Alignment compensation is performed based on the actual and theoretical coordinates of the back side of the marker point, the actual and theoretical coordinates of the front side of the target point, so that the lithographic pattern on side A is aligned with the lithographic pattern on side B.

[0010] In one embodiment, the line segments formed by connecting the targets are arranged in a triangular pattern; or, the line segments formed by connecting the marker points and the line segments formed by connecting the targets do not intersect each other.

[0011] In one embodiment, the target is at least one of a circle, triangle, rectangle, and cross shape;

[0012] In one embodiment, the marker point is a graphic obtained by exposing side A of the board, and the graphic is at least one of a circle, triangle, rectangle, and cross; or the marker point is a texture pattern of the board.

[0013] In one embodiment, obtaining the actual frontal coordinates of one or n marker points at predetermined positions on surface A includes:

[0014] Obtain the coordinates of the marker points in the pre-stored exposure image;

[0015] Alternatively, obtain the coordinates of the marker points collected by the front-facing component.

[0016] In one embodiment, the flipping method is either left-right or up-down, and the board specifications include board width and board height.

[0017] When the flipping method is left and right flipping, the theoretical coordinates of the back of the marker point are calculated based on the width of the plate and the actual coordinates of the front of the marker point, and the theoretical coordinates of the front of the target point are calculated based on the width of the plate and the actual coordinates of the back of the target point.

[0018] When the flipping method is up and down flipping, the theoretical coordinates of the back of the marker point are calculated based on the height of the board and the actual coordinates of the front of the marker point, and the theoretical coordinates of the front of the target point are calculated based on the height of the board and the actual coordinates of the back of the target point.

[0019] In one embodiment, alignment compensation includes performing at least one of displacement compensation, rotation compensation, and deformation compensation at the midpoint.

[0020] In one embodiment, before performing A-side exposure, the method further includes obtaining the mapping relationship between the front alignment component and the back alignment component; when calculating the back theoretical coordinates of the marker point and the front theoretical coordinates of the target point, the method further includes calculating the back theoretical coordinates of the marker point and the front theoretical coordinates of the target point based on the mapping relationship.

[0021] Secondly, this application also provides a back-side alignment apparatus for double-sided exposure, the apparatus being used to perform the method described above, including:

[0022] The coordinate acquisition module is used to acquire the actual front and back coordinates of the marker point, as well as the actual back and front coordinates of the target point.

[0023] The coordinate calculation module is used to calculate the theoretical back coordinates of the marker point and the theoretical front coordinates of the target point;

[0024] The alignment compensation module is used to perform alignment compensation based on the actual back coordinates and theoretical back coordinates of the marker point, the actual front coordinates and theoretical front coordinates of the target point, so that the lithographic pattern on side A is aligned with the lithographic pattern on side B.

[0025] Thirdly, this application also provides an exposure device, which includes a workpiece stage, an exposure assembly, a front alignment assembly, a back alignment assembly, and a back alignment device for double-sided exposure as described above.

[0026] The workpiece stage includes suction cups and motion guides for supporting and moving the sheet metal;

[0027] The exposure unit is used to expose the substrate.

[0028] The front alignment component is used to acquire the actual front coordinates of the target point, or to acquire the actual front coordinates of the target point and the actual front coordinates of the marker point.

[0029] The back alignment component is integrated into one side of the suction cup and is used to collect the actual coordinates of the back of the marker point;

[0030] The back-side alignment device for double-sided exposure is used to perform the back-side alignment method for double-sided exposure.

[0031] In one embodiment, the exposure apparatus includes a first exposure machine having a first workpiece stage and a first exposure assembly for performing A-side exposure;

[0032] The flipping mechanism is used to flip the sheet material exposed on side A to side B;

[0033] The second exposure machine has a second workpiece stage, a second exposure assembly, a second front alignment assembly, and a second back alignment assembly, and is used to perform B-side exposure and back alignment.

[0034] The second front-facing component collects the actual front coordinates of the target point, and the second back-facing component collects the actual back coordinates of the marker point.

[0035] or

[0036] The first exposure machine also includes a first front alignment component for acquiring the actual front coordinates of the marker points;

[0037] The second exposure unit acquires the actual front coordinates of the target point through the second front alignment component and acquires the actual back coordinates of the marker point through the second back alignment component.

[0038] Fourthly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the back-side alignment method for double-sided exposure as described above.

[0039] Fifthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the double-sided exposure back-side alignment method as described above.

[0040] Sixthly, this application also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, implements the alignment method described above.

[0041] The aforementioned alignment method, apparatus, exposure equipment, computer equipment, storage medium, and computer program products for double-sided exposure, compared to the traditional three-point alignment method, add an alignment point in the blank position. The lines connecting the target and marker points on the horizontal plane form a convex quadrilateral arrangement, creating at least four alignment points, which significantly improves the back-side alignment accuracy of double-sided exposure. Compared to four-point alignment, this application uses target points and marker points located on the A and B sides of the substrate to jointly form the alignment points. The coordinates of the marker points are obtained during front-side exposure, and the setting and formation of the alignment points are not limited by the substrate specifications. Furthermore, after flipping, the marker points are located on the X or Y axis of the suction cup, simplifying the back-side observation camera setup and adapting to more substrate specifications. Finally, because the alignment method uses several alignment points formed on both the A and B sides, the coordinates of the points can be acquired simultaneously from both the front and back sides, saving alignment time and further increasing exposure capacity. Attached Figure Description

[0042] Figure 1 This is the fourth labeling method for the alignment site in the existing technology;

[0043] Figure 2 This is a flowchart illustrating a double-sided exposure alignment method in one embodiment;

[0044] Figure 3 This is a flowchart illustrating the alignment method for double-sided exposure in another embodiment;

[0045] Figure 4 This is a schematic diagram of the target and marker points in a double-sided exposure alignment method in one embodiment;

[0046] Figure 5 This is a structural block diagram of a back-side alignment device for double-sided exposure in one embodiment;

[0047] Figure 6 This is an internal structural diagram of a computer device in one embodiment;

[0048] Figure 7 This is a top view of a schematic diagram of the exposure device in one embodiment;

[0049] Figure 8 This is a side view of a schematic diagram of the exposure device in one embodiment. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0051] Figure 2 This flowchart illustrates a method for back-side alignment in double-sided exposure, provided by an embodiment of this disclosure. This embodiment is applicable to situations where the specifications of the materials to be exposed differ, three-point alignment accuracy in back-side alignment is low, and traditional four-point alignment is costly. This method can be executed by a back-side alignment apparatus, which can be implemented in software and / or hardware, optionally through an electronic device such as a mobile terminal, PC, or server.

[0052] In one embodiment, such as Figure 2 As shown, a back-side alignment method for double-sided exposure is provided, including the following steps:

[0053] S1: When performing exposure on the A side of the substrate, obtain the actual front coordinates of 1 or n markers at predetermined positions on the A side and the actual back coordinates of m targets on the B side; the lines connecting the targets and markers on the horizontal plane form a convex quadrilateral arrangement, and the n markers are arranged with the row or column direction as the reference line.

[0054] S2: After exposure on side A is completed and the plate is flipped, obtain the actual coordinates of the back side of the marker points collected by the back side aligned with the component and the actual coordinates of the front side of the target points collected by the front side aligned with the component.

[0055] S3: Obtain information on the board specifications and flipping method; calculate the theoretical coordinates of the back side of the marker point based on the board specifications, flipping method, and the actual front coordinates of the marker point; calculate the theoretical front coordinates of the target point based on the board specifications, the flipping method, and the actual back coordinates of the target point.

[0056] S4: Based on the actual back coordinates and theoretical back coordinates of the marker point, the actual front coordinates and theoretical front coordinates of the target point, alignment compensation is performed to align the lithographic pattern on side A with the lithographic pattern on side B.

[0057] In step S1, the substrate is the substrate to be exposed, including but not limited to printed circuit boards (PCBs) in the field of integrated circuits, flat panel displays (FPDs) in the field of new displays, wafers and masks in the field of optoelectronic sensing, and photovoltaic silicon wafers in the field of photovoltaic, energy storage, and charging new energy. The predetermined position is the position that is different from the target point.

[0058] The arrangement of targets and markers forming convex quadrilaterals on a horizontal plane refers to moving targets and markers to the same horizontal plane, where the lines connecting targets and markers are at least convex quadrilaterals. For example, when there are a total of four targets and markers, their lines form convex quadrilaterals such as rectangles, parallelograms, rhombuses, and trapezoids. When there are a total of five or six targets and markers, four of the five or six points can always be found to form convex quadrilaterals.

[0059] The arrangement of n markers along a row or column direction as a baseline refers to a number of markers distributed along or on both sides of a straight line in a row or column direction of the board.

[0060] The back-side alignment component in step S2 is a component that acquires image data via an industrial camera. In step S2, the flip-board can be manually flipped or automatically flipped on a machine line.

[0061] In the aforementioned back-side alignment method, the three-point alignment is upgraded to the alignment of target and marker points located on surfaces A and B respectively. The lines connecting several alignment points can form at least a convex quadrilateral. Compared to the three-point alignment, which can only determine a triangle, and where the misalignment of a corner of the quadrilateral material between surfaces A and B is unknown, this alignment method determines a convex quadrilateral, clearly indicating the misalignment information of the four corners of the quadrilateral material, thus significantly improving the back-side alignment accuracy of double-sided exposed materials. Furthermore, the target and marker points in this application are not limited to four. With an increase in the number of target and alignment points, the back-side alignment accuracy will be further improved. For example, using more than three target points and more than two marker points will further improve the alignment accuracy.

[0062] Furthermore, compared to the traditional four-point alignment method, which places four alignment points on one side, this back-side alignment method uses a marking device integrated on one or both sides of the suction cup to mark the target points on the B side. The marking points are obtained during exposure on the A side or by acquiring the texture of the A side through the front-side alignment component. When dealing with multi-sized boards, the suction cup does not need additional marking devices for various board sizes, avoiding the reduction in suction cup adsorption capacity caused by multiple marking devices on the suction cup. Moreover, compared to the alignment method that places four alignment points on one side, this method uses a relatively fixed marking device, avoiding the problem of difficulty in determining the actual position of one target point on the B side during exposure on the A side due to different board sizes. Simultaneously, when the board is flipped, the marking points are always located on one side of the suction cup, facilitating the setup of the back-side alignment component. It is compatible with multi-sized boards. When there are n marking points, they are arranged in rows or columns, and in this case, the marking points are always located on one side of the suction cup, facilitating the setup of the back-side alignment component.

[0063] Finally, since the target and marker points are set on both sides of the plate, the alignment component can simultaneously acquire image information of the target and marker points when performing image acquisition. Compared with using an alignment component on one side to acquire the same number of target and marker point image information, the overall alignment time is shortened, thereby accelerating the exposure process and increasing exposure capacity.

[0064] In one embodiment, the line segments formed by connecting the target points constitute a triangle arrangement, similar to the three-point alignment, determining the offset of a triangular plane. The marker point is located outside the triangle, and thus the target points and the marker point form a convex quadrilateral to compensate for the offset at the missing corner of the board. For example, if there are a total of three target points and one marker point, with the target points located at the upper left, lower left, and lower right corners of the board, the line segments connecting the three target points form a triangle, and the marker point is located at the upper right corner of the board.

[0065] In another embodiment, the line segments formed by connecting the marker points and the line segments formed by connecting the target points do not intersect each other. Similarly, the lines connecting the target points and the marker points form a convex quadrilateral on a horizontal plane. For example, if there are two target points and two marker points, with the target points located at the upper left and lower left corners and the marker points located at the upper right and lower right corners, then when acquiring coordinates, both the front alignment component and the back alignment component acquire the coordinates of two points, instead of the front alignment component acquiring three points and the back alignment component acquiring one point. Compared to acquiring three points and one point with each alignment component, acquiring two points with each alignment component can further shorten the alignment point acquisition time, thereby accelerating the exposure process and increasing exposure capacity.

[0066] Optionally, the target point can be one of the following: a circle, a triangle, a rectangle, or a cross; or any combination of these shapes, such as a plum blossom pattern composed of five circles; or any combination of two or more of these shapes, such as a rectangle containing a circle, or a circle containing a cross. During data acquisition, the midpoint of the shape can be collected, such as the center of a circle, the centroid of a rectangle, etc.; multiple points can also be collected, such as the three corner points of a triangle, or the four corner points of a rectangle, etc. No limitations are imposed here.

[0067] Similarly, the marker point can be one of the following: a circle, a triangle, a rectangle, or a cross; or any combination of these shapes; or any two or more of these shapes. In this case, the marker point is obtained by exposing the material to surface A. Likewise, during data acquisition, the midpoint of the graphic, such as the center of a circle or the centroid of a rectangle, can be collected, or multiple points can be collected, such as the three corner points of a triangle or the four corner points of a rectangle. No limitations are imposed here.

[0068] In addition, the marker points can also be the texture of the board after exposure on surface A. In this case, the marker points are obtained by the front-facing component and the marker points are determined by the texture. Compared with forming marker points by exposing a specific pattern, no additional exposure area or additional marker point exposure time is required.

[0069] In the alignment method, obtaining the actual front coordinates of one or n marker points at predetermined positions on surface A can be achieved through the following steps: First, obtain the coordinates of the marker points in a pre-stored exposure image. For example, if marker points are already set in the pre-stored exposure image during exposure, obtain the actual front coordinates of the marker points using the pre-stored exposure image. Then, perform surface A exposure based on the pre-stored exposure image to expose the marker points onto surface A of the board. The pre-stored exposure image is a file in formats such as GDS. Obtaining the marker point positions using the pre-stored exposure image saves acquisition time and speeds up the alignment process compared to using an alignment camera.

[0070] Alternatively, obtaining the actual frontal coordinates of one or n marker points at predetermined positions on surface A can also be achieved using the following steps: obtaining the coordinates of the marker points acquired by the frontal alignment component. This step involves acquiring images of the marker points using the frontal alignment camera, and then obtaining the actual frontal coordinates of the marker points. This method can be used when textures are used as marker points.

[0071] The alignment method of this application can be adapted to both left-right flipping and up-down flipping. Specifically, in step S3, the information obtained about the flipping method is either left-right flipping or up-down flipping.

[0072] When the flipping method is left and right flipping, the theoretical coordinates of the back side of the marker point are calculated based on the board width and the actual front coordinates of the marker point, and the theoretical front coordinates of the target point are calculated based on the board width and the actual back coordinates of the target point. Specifically, if the board height is H and the board width is W, and the actual front coordinates of a marker point are (x1, y1), then the theoretical back coordinates of the marker point are (W-x1, y1); similarly, if the actual back coordinates of a target point are (x2, y2), then the theoretical front coordinates of the target point are (W-x2, y2).

[0073] When the flipping method is vertical, the theoretical coordinates of the back side of the marker point are calculated based on the board height and the actual front coordinates of the marker point, and the theoretical front coordinates of the target point are calculated based on the board height and the actual back coordinates of the target point. Specifically, if the board height of a certain board is H and the board width is W, and the actual front coordinates of a certain marker point are (x3, y3), then the theoretical back coordinates of the marker point are (x3, H-y3); similarly, if the actual back coordinates of a certain target point are (x4, y4), then the theoretical front coordinates of the target point are (x4, H-y4).

[0074] In specific embodiments, the alignment compensation of this alignment method includes at least one of displacement compensation, rotation compensation, and deformation compensation, such as performing only displacement compensation, or performing both displacement compensation and rotation compensation. For example, the alignment compensation can take the following steps: after obtaining the actual back coordinates and theoretical back coordinates of the marker point, the actual front coordinates and theoretical front coordinates of the target point, displacement compensation is performed first, followed by rotation compensation, and finally deformation compensation.

[0075] Alternatively, alignment compensation can be performed as follows: After obtaining the actual and theoretical coordinates of the marker point on its back side, and the actual and theoretical coordinates of the target point on its front side, displacement compensation, rotation compensation, and deformation compensation are performed cyclically until the actual and theoretical coordinates coincide. This method improves back-side alignment accuracy through multiple cyclic compensations.

[0076] The displacement compensation for alignment compensation mentioned above can be achieved by the following steps: comparing the actual back coordinates of a certain marker point with the theoretical back coordinates of the marker point, and adjusting the position of the plate or the pre-stored exposure image based on the difference between the two; or adjusting the position of the plate or the pre-stored exposure image based on the difference between the actual front coordinates of a certain target point and the theoretical front coordinates of the target point.

[0077] The steps for rotation compensation are as follows: Compare the actual back coordinates of several marker points on a vertical line, and connect the marker points to form a connecting line. Calculate the angle between the connecting line and the vertical line; this angle is the angle for rotation compensation. Similarly, the rotation compensation angle can also be calculated using the target points based on the actual point distribution.

[0078] Deformation compensation can be performed using the following steps: connect any marker point and target point, such that the connecting line between the marker point and target point can form two diagonals, and perform deformation expansion and contraction compensation based on the difference between the actual value and the theoretical value of the diagonal length.

[0079] The displacement compensation, rotation compensation, and deformation compensation steps described above are merely examples. In actual compensation, the methods are not limited to these. For example, other compensation methods may include rigid plate least squares fitting, plane equation fitting, vector decomposition, etc.

[0080] In one embodiment, step S1 is preceded by the step of obtaining the mapping relationship between the front alignment component and the back alignment component; step S3 further includes calculating the theoretical back coordinates of the marker point and the theoretical front coordinates of the target point based on the mapping relationship. Specifically, after calculating the theoretical back coordinates of the marker point based on the board specifications, flipping method, and actual front coordinates of the marker point; and calculating the theoretical front coordinates of the target point based on the board specifications, flipping method, and actual back coordinates of the target point; the theoretical back coordinates of the marker point and the theoretical front coordinates of the target point are adjusted according to the difference between the front alignment component and the back alignment component to form new theoretical coordinates. In addition, obtaining the mapping relationship between the front alignment component and the back alignment component also includes, when confirming that the centers of the front alignment component and the back alignment component are not on the same axis, moving the position of the front alignment component or moving the suction cup to move the back alignment component integrated on the suction cup, thereby making the front alignment component and the back alignment component coaxial.

[0081] This step allows for the calibration of the positions of the front and back alignment components, avoiding installation position errors of the alignment components and further improving the alignment accuracy of the back alignment.

[0082] Figure 3 This is a flowchart illustrating a double-sided exposure back-side alignment method provided in an embodiment of the present invention. The embodiments of the present invention further optimize the aforementioned embodiments, and can be combined with various optional solutions from one or more of the above embodiments. For example... Figure 4 As shown, taking an integrated circuit board (PCB) with three target points and one marker point, the target points are located at the upper left corner W, lower left corner E, and lower right corner R of the PCB, and the marker point Q is located at the upper right corner of the PCB, and the flipping method is left and right flipping, the back alignment method provided in this embodiment of the invention includes the following steps:

[0083] S200: Obtain the mapping relationship between the front alignment component and the back alignment component. Specifically, using the coaxial light source emission hole integrated in the suction cup back alignment component as a calibration feature, without placing any substrate to be exposed, the coaxial light emission hole of the back alignment component is directly captured by the front alignment component. The center point coordinates of the light emission hole (i.e., the center coordinates of the back alignment component) are obtained in the field of view of the front alignment component, thereby obtaining the coordinate position of the back alignment component relative to the front alignment component, which is (Δa, Δb).

[0084] S201: After the PCB is fed in, when the host computer performs A-side exposure, it exposes marker point 10 to the upper right corner of the A-side of the board using the exposure component, denoted as point Q. Simultaneously, the host computer directly obtains the actual front coordinates of marker point 10 based on the pre-stored exposure image, which is (X...). A1 ,Y A1 The marking device integrated into the left and lower sides of the suction cup marks the upper left, lower left, and lower right corners of the B-side of the material, forming target points 20, namely target point W, target point E, and target point R. Since the marking device is in a fixed position, the position of the target points can be directly known during marking. Therefore, after marking, the actual back coordinates of the target points are transmitted to the host computer. The actual back coordinates of the target points W (upper left), E (lower left), and R (lower right) are respectively (X... B2 ,Y B2 ), (X B3 ,Y B3 ), (X B4 ,Y B4 ); Both target 20 and marker point 10 are circular, and the line connecting them on the horizontal plane forms a convex quadrilateral. When acquiring coordinates, the center of the circle is acquired. A schematic diagram of the target and marker points for the double-sided exposure alignment method is shown below. Figure 4 As shown.

[0085] S202: After exposure on side A is completed and the plate is flipped; the actual coordinates of the back of the marker point Q integrated on the right side of the suction cup are collected from the assembly, which is (X... B1 ,Y B1 The front alignment component mounted on the gantry of the exposure equipment acquires the actual front coordinates of the upper left target point W, lower left target point E, and lower right target point R, respectively (X... A2 ,Y A2 ), (X A3 ,Y A3 ), (X A4 ,Y A4 ).

[0086] S203: Obtain information on the board specifications and flipping method, determine the board width as w, and the flipping method as left and right flipping. Based on the board width, the actual front coordinates of marker Q, and the actual back coordinates of target points W, E, and R, calculate the theoretical back coordinates of marker Q as (wX). A1 ,Y A1 The theoretical frontal coordinates of the target point are target point W(wX). B2 ,Y B2 ), target point E is (wX B3 ,Y B3 ), target point R is (wX B4 ,Y B4 ).

[0087] S204: Calculate the actual frontal coordinates of target point R and (X) A4 ,Y A4 ) and positive theoretical coordinates (wX) B4 ,Y B4 The difference between ΔX4 and ΔY4 is calculated, and displacement compensation is performed based on this difference. Where ΔX4 = X A4 -wX B4 -Δa;ΔY4=Y A4 -Y B4 -Δb.

[0088] S205: After displacement compensation, calculate the rotation angle θ = artan(|X) based on the actual back coordinates of marker point Q and the actual front coordinates of target point R. B1 -X A4 | / Y B1 -Y A4 ); Rotation compensation is performed based on the rotation angle. Wherein, based on X B1 -X A4 The sign of the value determines whether it is external or internal rotation. If X B1 -X A4 If X > 0, then it is internal rotation; if X B1 -X A4 If <0, it is exorotation.

[0089] S206: After rotation compensation, deformation compensation is performed. First, the differences between the actual coordinates and theoretical coordinates of the target point and the marker point are calculated. The differences between the marker point Q and the target points W, E, and R are (ΔX1, ΔY1), (ΔX2, ΔY2), (ΔX3, ΔY3), and (ΔX4, ΔY4), respectively.

[0090] (ΔX1,ΔY1)=(X B1 -wX A1 -Δa,Y A4 -Y B4 -Δb);

[0091] (ΔX2,ΔY2)=(X A2 -wX B2 -Δa,Y A2 -Y B2 -Δb);

[0092] (ΔX3,ΔY3)=(X A3 -wX B3 -Δa,Y A3 -Y B3 -Δb);

[0093] (ΔX3,ΔY3)=(X A4 -wX B4 -Δa,Y A4 -Y B4 -Δb);

[0094] If ΔX1≠ΔX2≠ΔX3≠ΔX 4， If ΔY1≠ΔY2≠ΔY3≠ΔY4, then deformation and expansion / contraction are considered to have occurred. Calculate the difference between the actual and theoretical values ​​of the lengths of the two diagonals. and Deformation expansion and contraction compensation is performed based on this length difference. Compared with the three-point method, this four-point deformation calculation method adds an extra edge, resulting in higher accuracy in deformation compensation.

[0095] ΔX5=∣(X B1 -X A3 )-(wX A11 -(wX B3 )∣,

[0096] ΔY5=∣(Y B1 -Y A3 )-(Y A1 -Y B3 )∣,

[0097] ΔX6=∣(X A2 -X A4 )-(WX B2 -(WX B4 ))∣,

[0098] ΔY6=∣(Y A2 -Y A4 )-(Y B2- Y B4 )∣.

[0099] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0100] Based on the same inventive concept, this application also provides a back-side alignment apparatus for implementing the back-side alignment method of double-sided exposure as described above. The solution provided by this apparatus is similar to the solution described in the above method. Therefore, the specific limitations of one or more back-side alignment apparatus embodiments provided below can be found in the limitations of the back-side alignment method above, and will not be repeated here.

[0101] In one embodiment, such as Figure 5 As shown, a back-side alignment device for double-sided exposure is provided, comprising: a coordinate acquisition module, a coordinate calculation module, and an alignment compensation module, wherein:

[0102] The coordinate acquisition module is used to acquire the actual front and back coordinates of the marker point, as well as the actual back and front coordinates of the target point.

[0103] The coordinate calculation module is used to calculate the theoretical back coordinates of the marker point and the theoretical front coordinates of the target point;

[0104] The alignment compensation module is used to perform alignment compensation based on the actual back coordinates and theoretical back coordinates of the marker point, the actual front coordinates and theoretical front coordinates of the target point, so that the lithographic pattern on side A is aligned with the lithographic pattern on side B.

[0105] The sources for the coordinate acquisition module to obtain the actual front coordinates of the marker points include obtaining the coordinates of the marker points in the pre-stored exposure image; or obtaining the coordinates of the marker points collected by the front alignment component.

[0106] In one embodiment, a sheet material processing information module is also included. This module is used to obtain the sheet material specifications, such as sheet height, sheet width, and the sheet material processing flipping method. The coordinate calculation module includes calculating the theoretical back coordinates of the marker point and the theoretical front coordinates of the target point based on the sheet material processing information module and the coordinate acquisition module.

[0107] In one embodiment, the alignment compensation module includes a displacement compensation module, a rotation compensation module, and a deformation compensation module, which respectively perform displacement compensation, rotation compensation, and deformation compensation.

[0108] In another embodiment, the alignment compensation module is a module that integrates displacement compensation, rotation compensation, and deformation compensation to achieve alignment compensation.

[0109] In one embodiment, the back alignment device further includes an alignment component calibration module, which is used to obtain the mapping relationship between the front alignment component and the back alignment component.

[0110] Each module in the aforementioned double-sided exposure back-side alignment device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the operations corresponding to each module.

[0111] In one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 6 As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communicating with external terminals via a network connection. When executed by the processor, the computer program implements a double-sided exposure back-side alignment method.

[0112] Those skilled in the art will understand that Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0113] In one embodiment, an exposure device is also provided, which is a standalone device, where one device completes the exposure of side A and side B of the substrate. For example... Figure 7 and Figure 8 As shown, Figure 7 This is a top view of the exposure equipment. Figure 8 This is a side view of the exposure equipment, which includes a workpiece stage, an exposure assembly 200, a front alignment assembly 300, a back alignment assembly 400, and a back alignment device for double-sided exposure as described above (not shown).

[0114] The workpiece stage includes a suction cup 101 and a motion guide rail (not shown) for carrying and moving the sheet metal;

[0115] Exposure assembly 200 is used to expose the substrate;

[0116] The front alignment component 300 is used to acquire the actual front coordinates of the target point, or to acquire the actual front coordinates of the target point and the actual front coordinates of the marker point.

[0117] The back alignment component 400 is integrated into one side of the suction cup 101 and is used to acquire the actual back coordinates of the marker point, such as... Figure 7 The center is located on the left side of the suction cup;

[0118] The back-side alignment device for double-sided exposure is used to perform the back-side alignment method for double-sided exposure.

[0119] In one embodiment, the workpiece stage 100 suction cup 101 further includes a marking device 102 integrated on one side of the suction cup 101 for marking to form a target. The marking device 102 can be located on one side of the suction cup or on both intersecting sides, such as... Figure 7 In the middle, the marking device is located on the left and top sides of the suction cup.

[0120] In one embodiment, the exposure equipment is a fully automated line, including a first exposure machine having a first workpiece stage and a first exposure assembly for performing A-side exposure;

[0121] The flipping mechanism is used to flip the sheet material exposed on side A to side B;

[0122] The second exposure machine has a second workpiece stage, a second exposure assembly, a second front alignment assembly, and a second back alignment assembly, and is used to perform B-side exposure and back alignment.

[0123] The second front-facing component collects the actual front coordinates of the target point, and the second back-facing component collects the actual back coordinates of the marker point.

[0124] or

[0125] The first exposure machine also includes a first front alignment component for acquiring the actual front coordinates of the marker points;

[0126] The second exposure unit acquires the actual front coordinates of the target point through the second front alignment component and acquires the actual back coordinates of the marker point through the second back alignment component.

[0127] Specifically, the first exposure machine includes a first workpiece stage and a first exposure assembly. The first exposure machine performs the A-side exposure operation of the board through the first workpiece stage and the first exposure assembly. After the A-side of the board is exposed, the flipping mechanism receives the board from the first exposure machine and performs a flipping operation to flip the board to the B-side. The second exposure machine receives the board from the flipping mechanism and performs the B-side exposure of the board after performing the back-side alignment method. The second exposure machine includes a second workpiece stage, a second exposure assembly, a second front alignment assembly, and a second back-side alignment assembly integrated on one side of the suction cup of the second workpiece stage. Before performing the back-side alignment method, the second front alignment assembly acquires the actual front coordinates of the target point, and the second back-side alignment assembly acquires the actual back coordinates of the marker point. Subsequently, the data is transmitted to the double-sided exposure back-side alignment device, and the back-side alignment method is performed through the back-side alignment device.

[0128] Alternatively, the first exposure machine includes a first workpiece stage, a first exposure component, and a first front alignment component. The first exposure machine performs the A-side exposure operation on the substrate using the workpiece stage and the first exposure component. The first front alignment component acquires the actual front coordinates of the marker points. After the A-side of the substrate is exposed, the flipping mechanism receives the substrate from the first exposure machine and performs a flipping operation, turning the substrate to the B-side. The second exposure machine receives the substrate transmitted by the flipping mechanism and, after performing the back alignment method, performs the B-side exposure. The second exposure machine includes a second workpiece stage, a second exposure component, a second front alignment component, and a second back alignment component integrated into one side of the suction cup of the second workpiece stage. Before performing the back alignment method, the second front alignment component acquires the actual front coordinates of the target points, and the second back alignment component acquires the actual back coordinates of the marker points. Subsequently, the data is transmitted to a double-sided exposure back alignment device, and the back alignment method is performed by the back alignment device.

[0129] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0130] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0131] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0132] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0133] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0134] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for back-side alignment using double-sided exposure, characterized in that, The method includes: When performing exposure on side A of the substrate, the actual front coordinates of 1 or n markers at predetermined positions on side A and the actual back coordinates of m targets on side B are obtained; the lines connecting the targets and the markers on the horizontal plane form a convex quadrilateral arrangement, and the n markers are arranged with the row direction or column direction as the reference line. After exposure on side A is completed and the plate is flipped, the actual back coordinates of the marked point acquired by the back alignment component and the actual front coordinates of the target point acquired by the front alignment component are obtained. Obtain information on the board specifications and flipping method; calculate the theoretical coordinates of the back side of the marker point based on the board specifications, the flipping method, and the actual front coordinates of the marker point; calculate the theoretical front coordinates of the target point based on the board specifications, the flipping method, and the actual back coordinates of the target point. Alignment compensation is performed based on the actual back coordinates and theoretical back coordinates of the marker point, the actual front coordinates and theoretical front coordinates of the target point, so that the lithographic pattern on side A is aligned with the lithographic pattern on side B.

2. The method according to claim 1, characterized in that, The line segments formed by the connecting lines of the targets constitute a triangular arrangement. Alternatively, the line segment formed by connecting the marked points and the line segment formed by connecting the target do not intersect each other.

3. The method according to claim 1, characterized in that, The target is at least one of the following: circular, triangular, rectangular, and cross-shaped; and / or The marker point is a graphic obtained by exposing side A of the board during exposure, and the graphic is at least one of a circle, triangle, rectangle, and cross, or the marker point is a texture pattern of the board.

4. The method according to claim 1, characterized in that, The process of obtaining the actual frontal coordinates of one or n marker points at predetermined positions on surface A includes: Obtain the coordinates of the marker points in the pre-stored exposure image; Alternatively, the coordinates of the marker points acquired by the front alignment component can be obtained.

5. The method according to claim 1, characterized in that, The flipping method is either left-right flipping or up-down flipping, and the board specifications include board width and board height; When the flipping method is left and right flipping, the theoretical coordinates of the back side of the marker point are calculated based on the width of the plate and the actual coordinates of the front side of the marker point, and the theoretical coordinates of the front side of the target point are calculated based on the width of the plate and the actual coordinates of the back side of the target point. When the flipping method is up and down flipping, the theoretical coordinates of the back side of the marker point are calculated based on the height of the board and the actual coordinates of the front side of the marker point, and the theoretical coordinates of the front side of the target point are calculated based on the height of the board and the actual coordinates of the back side of the target point.

6. The method according to claim 1, characterized in that, The alignment compensation includes performing at least one of displacement compensation, rotation compensation, and deformation compensation.

7. The method according to claim 1, characterized in that, Before performing A-side exposure, the procedure also includes the step of obtaining the mapping relationship between the front alignment component and the back alignment component; The calculation of the back-side theoretical coordinates of the marker point and the front-side theoretical coordinates of the target point also includes calculating the back-side theoretical coordinates of the marker point and the front-side theoretical coordinates of the target point according to the mapping relationship.

8. A back-side alignment device for double-sided exposure, characterized in that, The apparatus is used to perform the method as described in any one of claims 1-7, comprising: The coordinate acquisition module is used to acquire the actual front coordinates and actual back coordinates of the marker point, as well as the actual back coordinates and actual front coordinates of the target point; The coordinate calculation module is used to calculate the theoretical back-side coordinates of the marker point and the theoretical front-side coordinates of the target point; The alignment compensation module is used to perform alignment compensation based on the actual back coordinates and theoretical back coordinates of the marker point, the actual front coordinates and theoretical front coordinates of the target point, so that the lithographic pattern on side A is aligned with the lithographic pattern on side B.

9. An exposure apparatus, characterized in that, The exposure equipment includes a workpiece stage, an exposure assembly, a front alignment assembly, a back alignment assembly, and the back alignment device for double-sided exposure as described in claim 8. The workpiece stage includes a suction cup and a motion guide rail for supporting and moving the sheet metal; The exposure component is used to expose the substrate. The front alignment component is used to acquire the actual front coordinates of the target point, or to acquire the actual front coordinates of the target point and the actual front coordinates of the marker point. The back alignment component is integrated into one side of the suction cup and is used to acquire the actual back coordinates of the marker point; The back-side alignment device for double-sided exposure is used to perform the back-side alignment method for double-sided exposure.

10. The exposure apparatus according to claim 9, characterized in that, The exposure equipment includes a first exposure machine, having a first workpiece stage and a first exposure assembly, for performing A-side exposure; The flipping mechanism is used to flip the sheet material exposed on side A to side B; The second exposure machine has a second workpiece stage, a second exposure assembly, a second front alignment assembly, and a second back alignment assembly, and is used to perform B-side exposure and back alignment. The second front alignment component collects the actual front coordinates of the target point, and the second back alignment component collects the actual back coordinates of the marker point. or The first exposure machine also includes a first front alignment component for acquiring the actual front coordinates of the marker points; The second exposure unit acquires the actual front coordinates of the target point through the second front alignment component and acquires the actual back coordinates of the marker point through the second back alignment component.

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