A method for optimizing DMD magnification and angle calibration

Abstract

The present invention relates to the field of optical technology, and discloses a method for optimizing the calibration of DMD magnification and angle. First, four data graphics are set on the graphic file of the exposure machine, and the data graphics are output to the DMD digital micromirror. The DMD digital micromirror projects the corresponding four graphics through the projection point, and four projection graphics are correspondingly formed in the projection field of the DMD digital micromirror, wherein two projection graphics are distributed along the X axis, and the other two projection graphics are distributed along the Y axis. The four projection graphics are respectively photographed by a mobile three-dimensional motion platform to obtain the coordinate data of the four projection graphics. The magnification and angle in the X direction and the Y direction can be obtained by performing corresponding calculations through the four sets of coordinate data. The method reduces the error of the single-direction test result by calculating the magnification and angle in the X direction and the Y direction, so that the calibration of the DMD magnification and angle is optimized.

Description

Technical Field

[0001] The invention relates to the field of optical technology, and in particular to a method for optimizing DMD magnification and angle calibration. Background Art

[0002] LDI exposure equipment is a laser direct imaging device based on digital micromirrors. It uses computers to generate data graphics and outputs them to digital micromirrors. The light irradiating the digital micromirrors is reflected and enters the optical projection system. Based on a three-dimensional high-precision mobile platform, it can be dynamically projected to the corresponding imaging position on the substrate surface for exposure imaging. LDI exposure equipment uses multi-DMD scanning exposure. DMD digital micromirrors, as spatial light modulation devices, play a vital role in LDI exposure equipment.

[0003] When the magnification and angle of DMD projection must be within the error range, it matches the scanning range and scanning position of the high-precision mobile platform, and the LDI exposure equipment can expose the ideal graphics. However, due to the influence of mechanical processing and assembly, the actual DMD projection magnification and angle will deviate from the theoretical value, which makes the actual exposed image blurry, wrong image and missing image, so it is particularly important to reduce the deviation of DMD magnification and angle calibration. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method for optimizing DMD ratio and angle calibration, which solves the problem of large deviation in DMD ratio and angle calibration in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for optimizing DMD magnification and angle calibration comprises the following steps:

[0007] S1. Arrange the optical imaging lens and DMD digital micromirror on the three-dimensional motion platform of the exposure machine;

[0008] S2, setting four data graphics on the graphic file of the exposure machine, and outputting the four data graphics to the DMD digital micromirror;

[0009] S3, the DMD digital micromirror projects a corresponding pattern through a projection point, and four projection patterns are correspondingly formed within the projection field of the DMD digital micromirror, wherein two projection patterns are distributed along the X-axis, and the other two projection patterns are distributed along the Y-axis;

[0010] S4, moving the three-dimensional motion platform to obtain the center of one of the projection graphics, and making the position of the center of the projection graphics coincide with the position of the center of the optical imaging lens, at this time, recording the coordinate data;

[0011] S5, repeat step S4 to obtain the coordinate data of the four projection figures;

[0012] S6. Calculate the coordinate data of the centers of the two projection graphics in the X direction by a preset algorithm to obtain the magnification and angle in the X direction; calculate the coordinate data of the centers of the two projection graphics in the Y direction by a preset algorithm to obtain the magnification and angle in the Y direction.

[0013] Optionally, in step S6, the coordinate data of the centers of the two projection figures in the X direction are calculated by a preset algorithm to obtain the magnification and angle in the X direction, including:

[0014] Set the distance between the two figures in the X direction before magnification as L, calculate the difference ΔX in the X direction and the difference ΔY in the Y direction of the two projection figures in the X direction, and use the Pythagorean theorem to find the absolute distance M between the two projection figures, and calculate the magnification I = M / L;

[0015] The included angle is set to θ, tanθ = ΔY / ΔX.

[0016] Optionally, the data graph and the projection graph are both in the shape of a cross or a cross.

[0017] Optionally, the projection graphic is inclined at a certain angle relative to the data graphic.

[0018] Optionally, the DMD digital micromirror is provided with four projection points, which are respectively used to project the four projection patterns.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention provides a method for optimizing the calibration of DMD magnification and angle. The method forms two figures in the X direction and the Y direction in the DMD projection field of view, moves a three-dimensional motion platform to shoot a single figure to obtain its coordinate value, and simultaneously calculates the magnification and angle in the X direction and the Y direction, thereby reducing the error of the single-direction test result. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 It is a schematic diagram of the circular projection in the DMD projection field;

[0023] Figure 2for Figure 1 Schematic diagram of the projection of the center of a single circle;

[0024] Figure 3 A schematic diagram of a cross-shaped projection in the DMD projection field of view provided by an embodiment of the present invention;

[0025] Figure 4 for Figure 3 Schematic diagram of the projection of the center of a single cross figure;

[0026] Figure 5 It is the projection result diagram of the circular projection in the X direction;

[0027] Figure 6 It is the projection result diagram of the circular projection in the Y direction;

[0028] Figure 7 A projection result diagram of a cross figure projected in the X direction provided by an embodiment of the present invention;

[0029] Figure 8 This is a projection result diagram of the cross graphic provided in an embodiment of the present invention projected in the Y direction. DETAILED DESCRIPTION

[0030] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be understood that in the description of the present invention, the specific embodiments are only used to explain the present invention, rather than to limit the present invention. The term "including" and its variations used in the present invention are open inclusions, that is, "including but not limited to". The technical solution of the present invention is further explained below in conjunction with the accompanying drawings and through specific implementation methods; it can be understood that for the convenience of description, only the parts related to the present invention are shown in the accompanying drawings instead of all structures.

[0032] Please refer to Figure 3 and Figure 4 , Figure 3 A schematic diagram of a cross-shaped projection in the DMD projection field of view provided by an embodiment of the present invention; Figure 4 for Figure 3 Schematic diagram of the projection of the center of a single cross figure.

[0033] The present invention provides a method for optimizing DMD magnification and angle calibration, comprising the following steps:

[0034] S1. Arrange the optical imaging lens and DMD digital micromirror on the three-dimensional motion platform of the exposure machine;

[0035] S2, setting four data graphics on the graphic file of the exposure machine, and outputting the four data graphics to the DMD digital micromirror;

[0036] S3, the DMD digital micromirror projects a corresponding pattern through a projection point, and four projection patterns are correspondingly formed within the projection field of the DMD digital micromirror, two of which are distributed along the X-axis, and the other two are distributed along the Y-axis;

[0037] S4, moving the three-dimensional motion platform to obtain the center of one of the projection graphics, and making the position of the center of the projection graphics coincide with the position of the center of the optical imaging lens, at this time, recording the coordinate data;

[0038] S5, repeat step S4 to obtain the coordinate data of the four projection figures;

[0039] S6. Calculate the coordinate data of the centers of the two projection graphics in the X direction by a preset algorithm to obtain the magnification and angle in the X direction; calculate the coordinate data of the centers of the two projection graphics in the Y direction by a preset algorithm to obtain the magnification and angle in the Y direction.

[0040] As an optional implementation, in step S6, the coordinate data of the centers of the two projection graphics in the X direction are calculated by a preset algorithm to obtain the magnification and angle in the X direction, including:

[0041] Set the distance between the two figures in the X direction before magnification as L, calculate the difference ΔX in the X direction and the difference ΔY in the Y direction of the two projection figures in the X direction, use the Pythagorean theorem to obtain the absolute distance M between the two projection figures, and calculate the magnification I = M / L; set the angle as θ, tanθ = ΔY / ΔX.

[0042] As an optional implementation, a substrate may be disposed below the optical imaging lens, and the DMD digital micromirror may project a pattern onto the substrate.

[0043] As an optional implementation, the DMD digital micromirror is provided with four projection points, which are respectively used to project four projection patterns.

[0044] As a preferred embodiment, the distance between the projection points of the two projection figures in the X-axis direction is the maximum distance that can be set, and the distance between the projection points of the two projection figures in the Y-axis direction is the maximum distance that can be set. This setting can reduce the errors generated during the imaging process.

[0045] As an optional implementation, the data graph and the projection graph in the above method are both in the shape of a cross or a cross. This arrangement can reduce the deviation of the magnification and angle calibration.

[0046] Please refer to Figure 1 and Figure 2 , Figure 1 It is a schematic diagram of the circular projection in the DMD projection field; Figure 2 for Figure 1 Schematic diagram of the projection of the center of a single circle in .

[0047] In the past, in the test of DMD magnification and angle, circular projection was often used, and the projection was only performed in the X direction, and the magnification and angle in the X direction were calculated, such as Figure 1 As shown, there are two circles on the left and right in the DMD projection field of view. The mobile high-precision platform takes pictures of the two circular figures respectively. Figure 2 As shown, the center of the circle is obtained and the center position is moved to the position of the camera center. At this time, the coordinates of the platform are recorded to obtain two sets of coordinate data. The magnification and angle in the X direction are obtained through these two sets of data.

[0048] Please continue to refer to Figure 3 and Figure 4 .

[0049] In this embodiment, the graphic used for projection is a cross graphic.

[0050] In the DMD projection field of view, there are four cross patterns in the X-axis direction and the Y-axis direction. The high-precision platform is moved to shoot the four cross patterns respectively, and the center of the cross pattern is obtained and moved to the center of the camera. At this time, the coordinates of the platform are recorded to obtain four sets of coordinate data. The magnification and angle in the X and Y directions are obtained through these four sets of data.

[0051] As an optional implementation, the projection pattern is tilted at a certain angle compared to the data pattern, so that the edge of the projection pattern can be clearer.

[0052] Please refer to Figures 5 to 8 , Figure 5 This is the projection result of the circle in the X direction; Figure 6 It is the projection result diagram of the circle in the Y direction; Figure 7 A projection result diagram of a cross figure projected in the X direction provided by an embodiment of the present invention; Figure 8 This is a projection result diagram of the cross graphic provided in an embodiment of the present invention projected in the Y direction.

[0053] from Figure 5 and Figure 6It can be seen that the coordinates calculated using the circular projection have an X-direction deviation of 1.637 Pix (pixels) and a Y-direction deviation of 2.596 Pix; Figure 7 and Figure 8 It can be seen that the coordinates calculated using the cross-shaped projection have an X-direction deviation of 0.959 Pix and a Y-direction deviation of 1.058 Pix. By comparing the two sets of data, it is found that the deviations in the X and Y directions are significantly optimized after the cross-shaped projection is used. At the same time, the previous method of only testing the magnification and angle in the X direction is modified to simultaneously measuring the magnification and angle in the X and Y directions, which can reduce the error of the single-direction test results.

[0054] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for optimizing DMD magnification and angle calibration, It is characterized in that The following steps are involved: S1. Arrange the optical imaging lens and the DMD digital micromirror on the three-dimensional motion platform of the exposure machine; S2, setting four data graphics on the graphic file of the exposure machine, and outputting the four data graphics to the DMD digital micromirror; S3, the DMD digital micromirror projects a corresponding pattern through a projection point, and four projection patterns are correspondingly formed within the projection field of the DMD digital micromirror, two of which are distributed along the X-axis, and the other two are distributed along the Y-axis; S4, moving the three-dimensional motion platform to obtain the center of one of the projection graphics, and making the position of the center of the projection graphics coincide with the position of the center of the optical imaging lens, at this time, recording the coordinate data; S5, repeat step S4 to obtain the coordinate data of the four projection figures; S6. Calculate the coordinate data of the centers of the two projection graphics in the X direction by a preset algorithm to obtain the magnification and angle in the X direction; calculate the coordinate data of the centers of the two projection graphics in the Y direction by a preset algorithm to obtain the magnification and angle in the Y direction.

2. The method for optimizing DMD ratio and angle calibration according to claim 1, It is characterized in that In step S6, the coordinate data of the centers of the two projection figures in the X direction are calculated by a preset algorithm to obtain the magnification and angle in the X direction, including: Set the distance between the two figures in the X direction before magnification as L, calculate the difference ΔX in the X direction and the difference ΔY in the Y direction of the two projection figures in the X direction, and use the Pythagorean theorem to find the absolute distance M between the two projection figures, and calculate the magnification I = M / L; The included angle is set to θ, tanθ = ΔY / ΔX.

3. The method for optimizing DMD ratio and angle calibration according to claim 1, It is characterized in that The data graph and the projection graph are both in the shape of a cross or a cross.

4. The method for optimizing DMD ratio and angle calibration according to claim 1, It is characterized in that The projection graph is tilted at a certain angle relative to the data graph.

5. The method for optimizing DMD ratio and angle calibration according to claim 1, It is characterized in that The DMD digital micromirror is provided with four projection points, which are respectively used to project the four projection patterns.

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