Exposure system and exposure apparatus

Abstract

The application relates to an exposure system for exposing a three-dimensional structure on a workpiece, the exposure system is sequentially provided with a laser for emitting a laser beam, a beam expander for zooming and expanding the spot of the laser beam, an aperture for limiting the laser beam, a galvanometer for deflecting the direction of the laser beam, and a field lens group for ensuring the vertical emission of the laser beam along the advancing direction of the laser beam, the galvanometer comprises a reflecting sheet for reflecting the laser beam, the reflecting sheet can be rotated to expand the range of the laser beam emission, the range of the laser beam emission is 3mm*3mm-15mm*15mm, the exposure system can form a three-dimensional structure on the workpiece under the action of the aperture, the reflecting sheet in the galvanometer can be rotated to expand the range of the laser beam emission, so that the workpiece and the exposure system can expose multiple units without relative movement, and the exposure rate and the workpiece processing efficiency are greatly improved.

Description

Technical Field

[0001] This invention relates to an exposure system and an exposure apparatus. Background Technology

[0002] Due to its advantages such as high brightness, good monochromaticity, and strong directionality, lasers are widely used in processing fields such as laser direct writing and laser packaging. A commonly used system is a laser galvanometer scanning system. Its working principle involves amplifying and collimating the laser beam through a beam expander, then focusing it onto the surface of the workpiece with a specific power density after passing through a scanning focusing lens. The interaction between the laser and the workpiece requires a certain interaction time to provide the energy needed for the processing, thus achieving the processing of the workpiece. To form a three-dimensional exposure pattern on the workpiece, a grayscale aperture is generally used. Because the laser transmittance varies within the shape of the grayscale aperture, the final exposure intensity varies, thus forming a three-dimensional exposure pattern on the workpiece. However, the aperture size is generally on the millimeter scale, while the final exposure pattern is on the micrometer or even nanometer scale. To expose a three-dimensional shape, multiple exposures are required, and only one unit can be exposed at a time. After completing one unit, the moving platform or exposure system needs to move to the next unit for exposure. Because the moving speed of the moving platform or exposure system is slow, the efficiency is very low. Summary of the Invention

[0003] The purpose of this invention is to provide an exposure system with a fast exposure rate and high workpiece processing efficiency.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an exposure system for exposing a three-dimensional structure on a workpiece, wherein the exposure system comprises, in sequence along the laser beam propagation direction, a laser for emitting a laser beam, a beam expander for magnifying and expanding the spot of the laser beam, an aperture for limiting the laser beam, a galvanometer for deflecting the direction of the laser beam, and a field mirror assembly for ensuring that the laser beam is emitted perpendicularly, wherein the galvanometer includes a reflector for reflecting the laser beam, and the reflector is rotatable to expand the range of the laser beam emission.

[0005] Furthermore, the exposure system also includes a focusing lens for focusing the laser beam, the focusing lens being disposed between the aperture and the galvanometer, or between the galvanometer and the field lens.

[0006] Furthermore, the field lens group includes at least one field lens.

[0007] Furthermore, the field lens is a telecentric field lens.

[0008] Furthermore, the aperture is a grayscale aperture, and the grayscale of the grayscale aperture is different at different positions. The grayscale is lowest at the center position and the grayscale is higher closer to the edge of the grayscale aperture.

[0009] Furthermore, the laser is an ultraviolet laser.

[0010] The present invention also provides an exposure apparatus, including a frame and an exposure system disposed on the frame, a workpiece stage for fixing a workpiece, and a motion stage for driving the exposure system and the workpiece stage to move relative to each other, wherein a laser beam emitted by the exposure system forms a three-dimensional structure on the workpiece.

[0011] Furthermore, the exposure system is fixed on the motion stage.

[0012] Furthermore, the workpiece stage is fixed on the motion stage.

[0013] Furthermore, the exposure apparatus also includes a controller mounted on the frame, the controller being electrically connected to the exposure system and the motion stage.

[0014] The beneficial effects of the present invention are as follows: Under the action of the aperture, the exposure system of the present invention can form a three-dimensional structure on the workpiece, and the reflector in the galvanometer can be rotated to expand the range of laser beam emission, so that multiple units can be exposed without relative movement between the workpiece and the exposure system, which greatly improves the exposure rate and workpiece processing efficiency.

[0015] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the exposure system and workpiece according to an embodiment of the present invention;

[0017] Figure 2 This is a schematic diagram of another structure of the exposure system and the workpiece according to an embodiment of the present invention;

[0018] Figure 3 for Figure 1 Schematic diagram of different grayscale distribution areas of the medium grayscale aperture.

[0019] Figure 4 for Figure 1 A schematic diagram of different grayscale distribution areas of a hexagonal grayscale aperture.

[0020] Figure 5 for Figure 1 A schematic diagram of different grayscale distribution areas of a medium-circular grayscale aperture.

[0021] Figure 6 for Figure 1 A schematic diagram of different grayscale distribution areas of a medium-sized elliptical grayscale aperture. Detailed Implementation

[0022] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the referred mechanism or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0026] Please see Figure 1 and Figure 2 The exposure system shown in one embodiment of the present invention is used to expose a three-dimensional structure on a workpiece 2. The exposure system is arranged in sequence along the laser beam propagation direction as follows: a laser 11 for emitting a laser beam, a beam expander 12 for magnifying and expanding the laser beam spot, an aperture 13 for limiting the laser beam, a galvanometer 14 for deflecting the laser beam direction, and a field mirror group for ensuring that the laser beam is emitted perpendicularly. The galvanometer 14 includes a reflector (not shown) for reflecting the laser beam. The reflector can be rotated to expand the range of laser beam emission. The range of laser beam emission is 3mm*3mm-15mm*15mm.

[0027] The exposure system also includes a focusing mirror 16 for focusing the laser beam. The focusing mirror 16 is positioned between the aperture 13 and the galvanometer 14, and directs the focused laser beam onto the galvanometer 14. Figure 1Alternatively, two focusing lenses 16 may be provided, one positioned between the aperture stop 13 and the galvanometer 14, and the other positioned between the field lens group and the workpiece 2, see [link to relevant documentation]. Figure 2 By placing the focusing lens 16 below the field lens group, the focusing lens 16 and the field lens group can eliminate the focal length change caused by the galvanometer 14, thereby enabling the laser beam to accurately image on the workpiece 2.

[0028] Laser 11 is an ultraviolet laser, used to provide a single spectrum from the ultraviolet to the infrared band or a broad spectrum with a bandwidth of less than 100 nm. The wavelength of the light source can be freely selected according to the material properties of the workpiece 2, thereby increasing the versatility of the exposure system. Beam expander 12 is used to magnify and expand the beam to adjust the spot size of the emitted laser beam online, thus adapting to the spot size requirements of different workpieces 2. The specific spot size can be set according to actual needs. Aperture 13 is a grayscale aperture 13; please refer to [link to relevant documentation]. Figure 3-6 The grayscale aperture 13 can be triangular, circular, elliptical, quadrilateral, polygonal, etc., and its shape can be changed according to actual needs. The grayscale of the grayscale aperture 13 is different at different positions, with the lowest grayscale at the center and the grayscale increasing closer to the edge of the grayscale aperture 13. Therefore, the laser transmittance is different at different positions of the grayscale aperture 13, resulting in different exposure intensities of the laser beam emitted from the exposure system on the surface of the workpiece 2. A three-dimensional structure can be formed on the workpiece 2 with a single exposure, unlike traditional exposure methods that require multiple exposures to expose a three-dimensional structure, and each exposure can only expose one unit. After completing one unit, the platform moves to expose the next unit, resulting in very low exposure efficiency.

[0029] The galvanometer 14 contains two reflectors. One reflector deflects the laser beam in the X-direction, and the other deflects it in the Y-direction. Both reflectors are rotatable around a central axis, thereby expanding the horizontal emission range of the laser beam. Without relative movement between the workpiece 2 and the exposure system, the rotation of the reflectors allows for the exposure of multiple units within the movement range of the workpiece 2's surface. A typical unit is 0.1mm x 0.1mm, while the laser beam emission range is 3mm x 3mm to 15mm x 15mm, meaning 30 x 30 to 150 x 150 units can be exposed on the workpiece 2's surface. The rotation speed of the reflectors in the galvanometer 14 is approximately 900 times / s, while the relative movement rate between the exposure system and the workpiece 2 is approximately 100 times / s. The rotation speed of the reflectors is significantly greater than the excitation speed of the exposure system or the workpiece 2. Therefore, the exposure system of this invention can rapidly expose patterns on the workpiece 2.

[0030] The field lens assembly includes at least one field lens 15. In this embodiment, the field lens 15 is a telecentric field lens 15, which is used to ensure that the laser beam emitted from the galvanometer 14 is perpendicularly incident on the workpiece 2, avoiding vertical crosstalk problems when emitted at an angle. The number of telecentric field lenses 15 can be selected according to the actual required magnification, and is not specifically limited here.

[0031] Please see Figure 1 Laser 11 outputs a laser beam, which is expanded by beam expander 12, emitted to grayscale stop 13, focused by focusing lens 16, emitted to galvanometer 14 to change direction, and then focused onto workpiece 2 by telecentric field lens 15. The direction of laser beam movement is shown by the arrow. Or as shown by... Figure 2 The laser beam passing through the telecentric field mirror 15 is then focused onto the workpiece 2 again by the focusing mirror 16, with the direction of laser beam movement as shown by the arrow.

[0032] The present invention also provides an exposure device, which includes a frame and the exposure system shown above, a workpiece stage for fixing the workpiece, and a motion stage for driving the exposure system and the workpiece stage to move relative to each other. The laser beam emitted by the exposure system forms a three-dimensional structure on the workpiece.

[0033] The workpiece can be a rigid or flexible substrate, and the substrate can be any of glass, PET, PC, or PMMA, but is not limited to these; the choice can be made according to actual needs. After exposing the workpiece surface to form a three-dimensional structure, molds such as diffusers and light guides can be prepared, which are not listed here. The exposure system is set on a frame, and the exit port for emitting the laser beam is located above the workpiece stage, with the emitted laser beam perpendicular to the workpiece stage to process the workpiece located on the workpiece stage.

[0034] The exposure system is used to expose the workpiece and create an exposure pattern on it. The pattern can be any feasible shape, and the size of the workpiece is not specifically limited. This embodiment can process workpieces of different sizes.

[0035] In order to process a pattern on a workpiece, the exposure system and the workpiece surface need to move relative to each other in the horizontal direction. The exposure system can be fixed on a motion stage to move relative to the workpiece, or the workpiece stage can be fixed on a motion stage to move relative to the exposure system. At the same time, the exposure system and the workpiece can move relative to each other in the vertical direction to adjust the laser beam emitted by the exposure system to image the workpiece surface.

[0036] The exposure apparatus also includes a controller mounted on the frame, which is electrically connected to the exposure system and the motion stage. The controller is used to control the exposure system and the motion stage to perform the required operations.

[0037] The working principle of the exposure device is as follows: The workpiece is placed on the workpiece stage; the controller moves the stage to position the workpiece below the laser beam emitted by the exposure system, or moves the exposure system so that the laser beam enters the workpiece; the height of the exposure system relative to the workpiece is adjusted to meet the exposure requirements; the controller controls the stage to position the laser beam emitted by the exposure system in the initial exposure area; the controller controls the exposure system to scan and expose the pattern according to the set process parameters until the pattern in that area is fully exposed; the controller then moves the stage to the next exposure area, repeating the exposure process until all patterns are fully exposed. This process reduces the number of stage movements and increases the exposure rate.

[0038] In summary, the exposure system of the present invention can form a three-dimensional structure on the workpiece under the action of the aperture. The reflector in the galvanometer can be rotated to expand the range of laser beam emission, so that multiple units can be exposed without relative movement between the workpiece and the exposure system, which greatly improves the exposure rate and workpiece processing efficiency.

[0039] 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.

[0040] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An exposure system for exposing a three-dimensional structure on a workpiece, characterized in that, The exposure system is arranged along the laser beam's forward direction as follows: a laser emitting the laser beam, a beam expander for magnifying and expanding the laser beam's spot, an aperture limiting the laser beam, a galvanometer deflecting the laser beam's direction, and a field mirror assembly ensuring the laser beam's perpendicular emission. The aperture is a grayscale aperture with varying grayscale values ​​at different locations, being lowest at the center and increasing towards the edge. The galvanometer includes a reflector for reflecting the laser beam, comprising a first reflector and a second reflector. The first reflector deflects the laser beam in the X-direction, and the second reflector deflects it in the Y-direction. The reflectors are rotatable to expand the laser beam's emission range, allowing multiple units to be exposed without relative movement between the workpiece and the exposure system. The exposure system is electrically connected to a controller, which is configured to control the exposure system to scan and expose the pattern according to set process parameters until the pattern within the area is fully exposed.

2. The exposure system as described in claim 1, characterized in that, The exposure system further includes a focusing lens for focusing the laser beam, the focusing lens being disposed between the aperture and the galvanometer, or between the galvanometer and the field lens.

3. The exposure system as described in claim 1, characterized in that, The field lens group includes at least one field lens.

4. The exposure system as described in claim 3, characterized in that, The field lens is a telecentric field lens.

5. The exposure system as described in claim 1, characterized in that, The laser is an ultraviolet laser.

6. An exposure apparatus, characterized in that, The exposure apparatus includes a frame and an exposure system as described in any one of claims 1 to 5, a workpiece stage for fixing the workpiece, and a motion stage for driving the exposure system and the workpiece stage to move relative to each other, wherein the laser beam emitted by the exposure system forms a three-dimensional structure on the workpiece.

7. The exposure apparatus as claimed in claim 6, characterized in that, The exposure system is fixed on the motion stage.

8. The exposure apparatus as claimed in claim 6, characterized in that, The workpiece stage is fixed on the motion stage.

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