A maskless lithography apparatus and a maskless lithography method

Abstract

The application is suitable for the field of maskless lithography technology, and provides a maskless lithography device and a maskless lithography method. The maskless lithography device comprises an illuminating device for generating a plane array light, a digital micro-mirror device arranged on the light path of the plane array light emitted by the illuminating device, a stage assembly for carrying a substrate to be processed, a projection objective arranged between the stage assembly and the digital micro-mirror device, and a control unit electrically connected to the stage assembly and the digital micro-mirror device. The digital micro-mirror device has a plurality of micro-mirror units arranged in a longitudinal and lateral manner. The plane array light reflected by the micro-mirror units forms etching light spots on the substrate after passing through the projection objective. Each etching light spot is arranged in a longitudinal and lateral manner along a first direction and a direction perpendicular to the first direction, and the etching light spot can scan and irradiate the substrate along a second direction. The angle θ between the first direction and the second direction is an acute angle. The control unit controls the deflection of the micro-mirror units, so that the printed circuit on the substrate has continuous variability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of maskless lithography technology, in particular to a maskless lithography device and a maskless lithography method. BACKGROUND

[0002] Maskless lithography technology is a technology that directly uses data output by a graphic workstation to drive a laser imaging device to form an image on a printed circuit board (PCB) substrate, and is also known as laser direct imaging technology (LDI). Maskless lithography technology is a non-contact imaging technology, which can greatly simplify the printing process and save process time because it does not require the use of a mask plate, and has been widely used in the field of PCB printing.

[0003] The LDI device usually uses a digital micromirror device (DMD) to control the laser image irradiated onto the PCB substrate. The DMD is a micromirror array composed of a plurality of vertically and horizontally arranged micromirror units, each of which is an independent individual that can flip to different angles (usually three preset angles, i.e. +12°, 0° and -12°). When flipped to one of the preset angles, the laser beam is reflected and causes the laser beam to be imaged on the substrate through a projection objective, forming a bright pixel. When the micromirror unit deviates from the preset angle, the laser beam is reflected onto a beam absorption plate, which causes a dark pixel to be formed on the substrate. For the scheme of attaching a photosensitive dry film to the substrate, when the intensity of the laser irradiated onto the photosensitive dry film is higher than the threshold value, the photosensitive dry film receives the laser and undergoes a chemical reaction, and is adsorbed on the substrate. Further, by controlling the flipping state of the DMD and scanning on the substrate, the photosensitive dry film at each position on the substrate can receive laser irradiation of different intensities, and the circuit pattern can be exposed on the substrate.

[0004] In the traditional maskless lithography scheme, the spacing between each micromirror unit of the DMD is the same. For example, if a single micromirror unit is deflected to form a 10.8 μm spot on the substrate, the circuit width formed by scanning on the substrate is 10.8 μm or an integer multiple of 10.8 μm, and the continuous change of the circuit width cannot be achieved. SUMMARY

[0005] The purpose of the present application is to provide a maskless lithography device, which aims to solve the technical problem that the traditional maskless lithography device cannot print a circuit with a continuously variable width on the substrate.

[0006] The application is implemented as follows: a maskless lithography device, comprising an illuminating device for generating a planar array of light, a digital micro-mirror device arranged on the light path of the planar array of light emitted by the illuminating device, a stage assembly for carrying a substrate to be processed, a projection objective arranged between the stage assembly and the digital micro-mirror device, and a control unit electrically connected to the stage assembly and the digital micro-mirror device; the digital micro-mirror device has a plurality of micro-mirror units arranged in a matrix, the planar array of light reflected by the micro-mirror units forms etching spots on the substrate after passing through the projection objective; each etching spot is arranged in a matrix along a first direction and a direction perpendicular to the first direction, and the etching spot can scan the substrate along a second direction, and the included angle θ between the first direction and the second direction is an acute angle.

[0007] In an embodiment of the application, the stage assembly comprises a stage body and a moving platform connected to the stage body; the substrate is arranged on the side of the moving platform facing the projection objective, and the moving platform can drive the substrate to move under the control of the control unit.

[0008] In an embodiment of the application, the substrate comprises a first bottom surface in contact with the moving platform, a second bottom surface opposite to the first bottom surface and facing the projection objective, and a first side surface connecting the first bottom surface and the second bottom surface; the first side surface is parallel to the first direction, and the moving platform can drive the substrate to move along the second direction.

[0009] In an embodiment of the application, the digital micro-mirror device further comprises a digital micro-mirror main board carrying each micro-mirror unit, and a digital micro-mirror power supply electrically connected to the digital micro-mirror main board and used for supplying power to the digital micro-mirror main board; each micro-mirror unit is arranged in a matrix on the side of the digital micro-mirror main board opposite to the illuminating device, the digital micro-mirror main board can be connected to the control unit, and the digital micro-mirror main board can drive each micro-mirror unit to switch between a first posture, a second posture and a third posture under the control of the control unit.

[0010] In an embodiment of the application, the maskless lithography device further comprises a light beam absorption plate arranged on the light path of the planar array of light after passing through the digital micro-mirror device when the micro-mirror unit is in the second posture and the third posture.

[0011] In one embodiment of this application, the digital micromirror device has 1080 rows and 1920 columns of micromirror units arranged in a horizontal and vertical manner, and the distance between adjacent micromirror units is 10.8 μm; or, the digital micromirror device has 1600 rows and 2560 columns of micromirror units arranged in a horizontal and vertical manner, and the distance between adjacent micromirror units is 7.56 μm.

[0012] In one embodiment of this application, in the longitudinally and transversely distributed micromirror units, the connecting lines between each row of micromirror units are configured to be parallel to the plane on which the substrate is located.

[0013] In one embodiment of this application, the illumination device includes a laser generator for emitting laser light to the digital micromirror device, and a beam expander disposed between the laser generator and the digital micromirror device.

[0014] Another object of this application is to provide a maskless lithography method applicable to the maskless lithography equipment described above, the maskless lithography method comprising the following steps:

[0015] The substrate is placed on the stage assembly;

[0016] The lighting device starts working and generates the area array light. The area array light is projected onto the substrate through the digital micromirror device and the projection lens, and the etching spot is arranged longitudinally and laterally along the first direction and the direction perpendicular to the first direction.

[0017] The control unit controls the stage assembly to move the substrate along the second direction. At the same time, the control unit controls the deflection state of each micromirror unit according to the pattern formed by photolithography on the substrate as needed. This step is repeated until a preset photolithography pattern is formed on the substrate.

[0018] Implementing any embodiment of the maskless photolithography apparatus provided in this application has at least the following beneficial effects:

[0019] The area array light emitted by the illumination device passes through the digital micromirror device and the projection lens in the optical path, forming an etching spot on the substrate. The etching spots formed by each micromirror unit are arranged longitudinally and transversely along a first direction and a direction perpendicular to the first direction. Under the control of the control unit, the etching spot can scan and illuminate the substrate along a second direction. The angle θ between the first direction and the second direction is an acute angle. In this way, the control unit can control the multiple longitudinally and transversely arranged micromirror units of the digital micromirror device to deflect according to a preset timing relationship and reflect the light beam onto the substrate. Finally, it can scan circuit lines on the substrate with a width that is not an integer multiple of the etching spot diameter, so that the width of the printed circuit on the substrate has continuous variability. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of a maskless lithography apparatus provided in one embodiment of this application;

[0022] Figure 2 This is a schematic diagram illustrating the working principle of a maskless lithography device provided in one embodiment of this application;

[0023] Figure 3 This is a schematic diagram illustrating the working principle of a digital micromirror device provided in one embodiment of this application.

[0024] The details of the reference numerals used in the above figures are as follows:

[0025] 1-Illumination device; 10-Beam; 11-Etched spot; 111-First direction; 112-Second direction; 2-Beam expander; 3-Digital micromirror device; 31-Micromirror unit; 32-Digital micromirror mainboard; 4-Stage assembly; 40-Substrate; 401-First side; 402-Second side; 403-Third side; 404-Fourth side; 5-Projection lens; 6-Control unit; 7-Beam absorption plate. Detailed Implementation

[0026] 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.

[0027] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it may be directly or indirectly located on that other component. When a component is referred to as "connected to" another component, it may be directly or indirectly connected to that other component. The terms "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate orientations or positions based on the orientations or positions shown in the accompanying drawings, and are for ease of description only, and should not be construed as limiting the technical solution. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. "A plurality of" means two or more, unless otherwise explicitly defined.

[0028] To illustrate the technical solutions described in this application, the following detailed description is provided in conjunction with specific drawings and embodiments.

[0029] Please see Figure 1 and Figure 2 One embodiment of this application provides a maskless photolithography apparatus, including an illumination device 1 for generating area array light, a digital micromirror device 3 disposed in the optical path of the light beam 10 emitted by the illumination device 1, a stage assembly 4 for carrying a substrate 40 to be processed, a projection lens 5 disposed between the stage assembly 4 and the digital micromirror device 3, and a control unit 6 electrically connecting the stage assembly 4 and the digital micromirror device 3; the digital micromirror device 3 has a plurality of longitudinally and transversely arranged micromirror units 31, and the area array light reflected by the micromirror units 31 forms etching spots 11 on the substrate 40 after passing through the projection lens 5; each etching spot 11 is longitudinally and transversely arranged along a first direction 111 and a direction perpendicular to the first direction 111, and the etching spot 11 can scan and irradiate the substrate 40 along a second direction 112, and the included angle θ between the first direction 111 and the second direction 112 is an acute angle.

[0030] Specifically, the maskless lithography equipment provided in this embodiment works as follows:

[0031] Please see Figure 1 and Figure 2 The area array light emitted by the illumination device 1 illuminates the digital micromirror device 3. The digital micromirror device 3 has several micromirror units 31 arranged in a vertical and horizontal manner. Under the control of the control unit 6, each micromirror unit 31 can switch between three deflection postures (i.e., the first posture, the second posture, and the third posture). When the micromirror unit 31 is in the first posture, the area array light emitted by the illumination device 1 is reflected by the micromirror unit 31 and illuminates the projection lens 5, and is imaged onto the substrate 40 by the projection lens 5. In this way, by attaching a photosensitive dry film to the substrate 40, when the intensity of the area array light illuminating the photosensitive dry film is higher than a threshold, the photosensitive dry film will receive the area array light and undergo a physicochemical reaction, adsorbing onto the substrate 40. Furthermore, the control unit 6 controls the flipping state of the micromirror units 31 of the digital micromirror device 3 and controls the digital micromirror device 3 to scan the substrate 40, so that the photosensitive dry film at different locations on the substrate 40 receives the area array light irradiation of different intensities, exposing the circuit diagram on the substrate.

[0032] Implementing the maskless lithography equipment provided in this embodiment has at least the following beneficial technical effects:

[0033] The area array light emitted by the illumination device 1 passes sequentially through the digital micromirror device 3 and the projection lens 5, forming etching spots 11 on the substrate 40. The etching spots 11 formed by each micromirror unit 31 are arranged longitudinally and transversely along the first direction 111 and the direction perpendicular to the first direction 111, forming an etching spot matrix 11. Under the control of the control unit 6, the etching spots 11 can scan and illuminate the substrate 40 along the second direction 112. The angle θ between the first direction 111 and the second direction 112 is an acute angle. In this way, the control unit 6 can control the multiple longitudinally and transversely arranged micromirror units 31 of the digital micromirror device 3 to deflect according to a preset timing relationship and reflect the area array light onto the substrate 40. Finally, circuit lines with a width that is not an integer multiple of the diameter of the etching spot 11 can be scanned on the substrate 40, so that the width of the printed circuit on the substrate 40 has continuous variability.

[0034] As a specific embodiment, the illumination device 1 includes a laser generator for emitting a beam 10 to the digital micromirror device 3, and a beam expander 2 disposed between the laser generator and the digital micromirror device 3. The beam 10 output by the laser generator is first expanded and collimated by the beam expander 2, becoming an array beam 10 and illuminating the digital micromirror device 3. After selective reflection by the digital micromirror device 3 and refraction by the projection lens 5, it is projected onto the substrate 40 to form an array of etched spots 11. More preferably, the illumination device 1 also includes a shaping mirror (not shown in the figure) disposed between the beam expander 2 and the digital micromirror device 3. The shaping mirror is used to change the wavefront of the beam 10, shaping the beam 10 after expansion by the beam expander 2 into an array beam with uniform wavefront intensity, so that the light intensity of each etched spot 11 is closer.

[0035] Please see Figure 1 and Figure 2Specifically, the etching spots 11 formed by each micromirror unit 31 are arranged longitudinally and transversely along the first direction 111 and the direction perpendicular to the first direction 111. Under the control of the control unit 6, the etching spots 11 can scan and irradiate the substrate 40 along the second direction 112. The angle θ between the first direction 111 and the second direction 112 is an acute angle. Thus, when it is necessary to print circuit lines on the substrate 40 with a width that is not an integer multiple of the diameter of the etching spot 11, the control unit 6 can control the multiple longitudinally and transversely arranged micromirror units 31 of the digital micromirror device 3 to reflect the beam 10 onto the substrate 40 according to a preset timing relationship, thereby scanning a line with a width equal to a[1±(n-1)sinθ] on the substrate 40 (where a represents the diameter of the etching spot 11 and n is the number of adjacent micromirror units 31 in the first orientation along the first direction 111). The angle between the first direction 111 and the second direction 112 is set to θ. The exposure threshold is set by the control unit, and the exposure time is controlled so that the area of ​​repeated exposure reaches the threshold, causing the photosensitive dry film to undergo a physicochemical reaction, thereby realizing the continuous variability of the circuit lines on the substrate 40.

[0036] For example, if θ is set to 30° and the diameter of the etching spot 11 is 1μm, but a circuit line with a width of 1.5μm is actually needed, two adjacent micro-mirror units 31 on the first direction 111 reflect the light beam 10 to the substrate 40. The threshold is set to 1, so that the etching spot 11 has sufficient light intensity to cause the photosensitive dry film to undergo a physicochemical reaction and be adsorbed on the substrate. In this way, when the etching spot 11 scans across the surface of the substrate 40 along the second direction 112, a circuit line with a width of 1.5μm can be etched on the surface of the substrate 40. The diameter of the etching spot 11 is 1 μm. When a circuit line with a width of 0.5 μm is actually required, two adjacent micro-mirror units 31 set on the first direction 111 reflect the light beam 10 to the substrate 40. The intensity of the light beam 10 is configured such that the superposition of the two etching spots 11 has sufficient light intensity to cause the photosensitive dry film to undergo a physicochemical reaction and be adsorbed on the substrate. That is, the threshold is set to 2. In this way, when the etching spot 11 scans across the surface of the substrate 40 along the second direction 112, a circuit line with a width of 0.5 μm can be etched on the surface of the substrate 40.

[0037] More specifically, taking the case where the diameter of the etching spot 11 is 1μm, but a circuit line with a width of 1.5μm is actually required, and θ is 30° as an example, in this case, the intensity of the beam 10 is configured such that a single etching spot 11 has sufficient light intensity to cause the photosensitive dry film to undergo a physicochemical reaction and be adsorbed onto the substrate. When the substrate 40 moves to the first row of etching spots 11 (in the principle description of this embodiment, etching spots 11 distributed along the direction parallel to the first direction 111 are in a column, and etching spots 11 distributed along the direction perpendicular to the first direction 111 are in a row) to etch the position to be etched, the control unit 6 controls the micromirror unit 31 in the first row corresponding to the position to be etched to deflect, thereby etching a first region with a width of 1μm at the position to be etched on the substrate 40; each etching spot 11 continues to move along the second direction 112 until the second row of etching spots 11 adjacent to the first row of etching spots 11 etch the position to be etched, the control unit 6 controls the micromirror unit 31 in the second row corresponding to the position to be etched (that is, a micromirror unit 31 in the second row that is in the same column as the micromirror unit 31 in the first row that has been deflected and etched circuits) to deflect, thereby etching a second region with a width of 1μm at the position to be etched on the substrate 40. Because there is a 30° angle between the second direction 112 and the first direction 111, the second region and the first region overlap by 0.5 μm. This allows a circuit line with a width of 1.5 μm to be etched at the desired etching location. Furthermore, under the program control of the control unit 6, each etching spot 11 continues to move along the second direction 112, and each micromirror unit 31 deflects according to a timing sequence, thus etching a circuit line with a width of 1.5 micrometers onto the substrate 40.

[0038] Similarly, taking the case where the diameter of the etching spot 11 is 1μm, but a circuit line with a width of 0.5μm is actually required, and θ is 30° as an example, in this case, the intensity of the beam 10 is configured to be the superposition of two etching spots 11 to have sufficient light intensity so that the photosensitive dry film can undergo a physicochemical reaction and be adsorbed onto the substrate. When the substrate 40 moves to the first row of etching spots 11 (in the principle description of this embodiment, etching spots 11 distributed along the direction parallel to the first direction 111 are in a column, and etching spots 11 distributed along the direction perpendicular to the first direction 111 are in a row) to illuminate the position to be etched, the control unit 6 controls the micro-mirror unit 31 in the first row corresponding to the position to be etched to deflect, thereby projecting a first spot with a diameter of 1μm onto the position to be etched on the substrate 40; each etching spot 11 continues to move along the second direction 112 until the second row of etching spots 11 adjacent to the first row of etching spots 11 illuminates the position to be etched, the control unit 6 controls the micro-mirror unit 31 in the second row corresponding to the position to be etched (that is, a micro-mirror unit 31 in the second row that is in the same column as the micro-mirror unit 31 in the first row that has been deflected and etched circuits) to deflect, thereby projecting a second spot with a diameter of 1μm onto the position to be etched on the substrate 40. Because there is a 30° angle between the second direction 112 and the first direction 111, the second light spot and the first light spot overlap by 0.5 μm. Only the overlapping area is simultaneously irradiated by the first and second light spots. Since the effect of the light beam 10 on the photosensitive dry film is superimposed, even if the light spots irradiate the photosensitive dry film at different times, as long as the total intensity of the etching light spots 11 is greater than the threshold, the corresponding circuit line can be etched at the location to be etched. Therefore, in this way, a circuit line with a width of 0.5 μm can be etched at the location to be etched. Furthermore, under the program control of the control unit 6, each etching light spot 11 continues to run along the second direction 112, and each micromirror unit 31 deflects according to the timing sequence, thereby etching a circuit line with a width of 0.5 micrometers on the substrate 40.

[0039] In actual operation, the value of θ is usually between 5° and 15°. Moreover, the circuit to be etched on the substrate 40 is very complex. The control unit 6 can control the digital micromirror device 3 to change the state of the micromirror unit 31 in real time, and repeatedly transmit the etching spot 11 to the substrate 40 and scan it to achieve multiple exposures or repeated exposures, so that the required circuit pattern can be etched on the substrate 40.

[0040] In one embodiment of this application, the stage assembly 4 includes a stage body and a movable platform connected to the stage body; the substrate 40 is disposed on the side of the movable platform facing the projection lens 5, and the movable platform can drive the substrate 40 to move under the control of the control unit 6.

[0041] Please see Figure 1 andFigure 2 Specifically, when the control unit 6 controls the moving platform to move the substrate 40, it also controls the deflection state of each micromirror unit 31 of the digital micromirror according to the specific pattern of the circuit diagram drawn on the substrate 40, so that complex circuits with continuously variable widths can be drawn on the substrate 40.

[0042] As a specific embodiment, the stage body and the moving platform are connected by a track. The stage assembly 4 also includes a motor for driving the movement of the moving platform, and a bracket for supporting the output component of the laser generator, the beam expander 2, the digital micromirror device 3 and the projection lens 5. The bracket is connected to the stage body, and the projection lens 5 connected to the bracket is positioned facing the moving platform.

[0043] Please see Figure 1 and Figure 2 In one embodiment of this application, the substrate 40 includes a first bottom surface that contacts the moving platform, a second bottom surface that is opposite to the first bottom surface and faces the projection lens 5, and a first side surface 401 and a second side surface 402 that connect the peripheries of the first bottom surface and the second bottom surface and are perpendicular to each other; the first side surface 401 is parallel to the first direction 111, and the moving platform can drive the substrate 40 to move along the second direction 112.

[0044] Please see Figure 1 and Figure 2 Specifically, the PCB can be rectangular and includes a third side 403 parallel to the first side 401 and a fourth side 404 parallel to the second side 402. The first side 401 and the third side 403 are arranged parallel to the first direction 111, and correspondingly, the second side 402 and the fourth side 404 are perpendicular to the first direction 111. The moving platform drives the substrate 40 to move along the second direction 112. In this way, the control unit 6, according to the circuit printed on the substrate 40, while the moving platform drives the substrate 40 to move, controls the multiple vertically and horizontally arranged micromirror units 31 of the digital micromirror device 3 to reflect the light beam 10 onto the substrate 40 in a timing sequence, thereby scanning circuit lines with continuously variable widths on the substrate 40.

[0045] The advantage of this approach is that when setting up the digital micromirror device 3, it is only necessary to configure the digital micromirror device 3 to selectively reflect the beam 10 emitted from the beam expander 2 to the projection lens 5, without having to consider the direction of the connection between the light spots formed after reflection when setting the orientation of the digital micromirror device 3. This simplifies the orientation relationship of each optical element in the maskless lithography equipment and simplifies the installation and debugging of the maskless lithography equipment.

[0046] Please see Figure 3For example, if the first, second, and third postures of the micromirror unit 31 are -12°, 0°, and +12° respectively, the output of the illumination device 1 can be set horizontally. After the digital micromirror device 3 is set in a direction perpendicular to the beam 10, its upper part is rotated 33° toward the position of the illumination device 1. In this way, when the micromirror unit 31 in the digital micromirror device 3 is in the first posture, the corresponding beam 10 can be reflected to the projection lens 5 and form an etched spot 11 on the substrate 40.

[0047] In the traditional approach, the digital micromirror device 3 needs to be rotated further along the axis of its reflective surface. During this process, the lines connecting the multiple etching spots 11 projected onto the substrate 40 after reflection by the digital micromirror device 3 are generally parallelograms. This is undoubtedly detrimental to the control of the circuit printing of the control unit 6 and will greatly increase the complexity of the control program. Therefore, it is often necessary to perform more complex adjustments to the orientation of the digital micromirror device 3 so that the lines connecting the multiple etching spots 11 are generally rectangular, making the installation and debugging of the maskless lithography equipment complex and cumbersome.

[0048] Corresponding to this embodiment, this application provides a maskless photolithography method, which includes the following steps:

[0049] Place the substrate 40 on the stage assembly 4;

[0050] The lighting device 1 starts working and generates a surface array light. The surface array light passes through the digital micromirror device 3 and the projection lens 5 and projects an etching spot 11 onto the substrate 40. The etching spot 11 is arranged longitudinally and laterally along the first direction 111 and the direction perpendicular to the first direction 111.

[0051] The control unit 6 controls the stage assembly 4 to move the substrate 40 along the second direction 112. At the same time, the control unit 6 controls the deflection state of each micro-mirror unit 31 according to the pattern formed by photolithography on the substrate 40 as needed. This step is repeated until a preset photolithography pattern is formed on the substrate 40.

[0052] The maskless lithography method provided in this embodiment projects etching spots 11 arranged longitudinally and transversely along a first direction 111 and perpendicular to the first direction 111 onto a substrate 40 using an illumination device 1. Simultaneously, a stage assembly 4 moves the substrate 40 along a second direction 112. This allows for multiple exposures and repeated exposures to etch complex circuits with continuously variable widths onto the substrate 40, achieving continuous variability of the circuit lines on the substrate 40. The control unit 6 controls the stage assembly 4 to move the substrate 40 along the second direction 112. Thus, when setting up the digital micromirror device 3, it is only necessary to configure the digital micromirror device 3 to selectively reflect the area array light from the beam expander 2 to the projection lens 5, without needing to consider the direction of the lines connecting the reflected light spots when setting the orientation of the digital micromirror device 3. This simplifies the orientation relationships of the various optical components in the maskless lithography equipment and simplifies the installation and debugging of the equipment.

[0053] As a specific embodiment, the lighting device 1 includes a lighting device 1 positioned directly opposite the digital micromirror device 3, and a beam expander 2 positioned between the lighting device 1 and the digital micromirror device 3. The light beam 10 generated by the lighting device 1 becomes a surface array light after being expanded by the beam expander 2. The surface array light is projected onto the substrate 40 through the digital micromirror device 3 and the projection lens 5 to form an etching spot 11.

[0054] In one embodiment of this application, the digital micromirror device 3 further includes a digital micromirror motherboard 32 carrying each micromirror unit 31, and a digital micromirror power supply electrically connected to the digital micromirror motherboard 32 and used to supply power to the digital micromirror motherboard 32; each micromirror unit 31 is arranged longitudinally and laterally on the side of the digital micromirror motherboard 32 opposite to the beam expander 2; the digital micromirror motherboard 32 can be connected to the control unit 6; and the digital micromirror motherboard 32 can drive each micromirror unit 31 to switch between a first attitude, a second attitude, and a third attitude under the control of the control unit 6.

[0055] More specifically, the digital micromirror mainboard 32 includes a reflective mainboard for supporting each micromirror unit 31 and a control mainboard for electrical connection with the control unit 6. The reflective mainboard and the control mainboard are connected by a cable, and the reflective mainboard is provided with a DMD chip for controlling each micromirror unit 31. The digital micromirror power supply is used to supply power to the control mainboard and the reflective mainboard. The control unit 6 is equipped with corresponding program control software, which can control the rotation of each micromirror unit 31 on the digital micromirror device 3 by outputting coded signals to the digital micromirror unit, so as to selectively reflect the etching spot 11 to the projection lens 5.

[0056] In one embodiment of this application, the digital micromirror device 3 has micromirror units 31 arranged in 1080 rows and 1920 columns, or 1600 rows and 2560 columns, with the distance between adjacent micromirror units 31 being 10.8 μm or 7.56 μm; more specifically, the angle θ between the first direction 111 and the second direction 112 ranges from 5° to 15°. This allows for beam 10 etching at a resolution of 1920*1080 or 1600*2560. Furthermore, after further imaging by the projection lens 5, the area of ​​the etching spot 11 can be reduced to the nanometer level, thereby reducing the diameter of the etching spot 11 and enabling the maskless lithography equipment to have a smaller minimum linewidth, thus improving the precision of beam 10 etching.

[0057] Please see Figure 1 In one embodiment of this application, the maskless lithography apparatus further includes a beam absorption plate 7, which is disposed on the optical path of the beam 10 after passing through the digital micromirror device 3 when the micromirror unit 31 is in the second and third postures.

[0058] The purpose of the beam absorber plate 7 is to absorb the light beam 10 that is not irradiated onto the substrate 40 after being reflected by the micromirror unit 31. In beam 10 etching, a high-energy illumination device 1 is often used to ensure that the photosensitive dry film can undergo a physicochemical reaction after being irradiated by the beam 10. Besides needing an intensity higher than a threshold, the wavelength of the beam 10 irradiating the photosensitive dry film should also be short enough to ensure that a single photon has sufficient energy to cause a physicochemical reaction in the photosensitive dry film. Therefore, beam 10 has a high-energy characteristic in beam 10 etching. Furthermore, each micromirror unit 31 has a first attitude, a second attitude, and a third attitude. The etching beam 10 that is not reflected onto the substrate 40 will be reflected in two other specific directions in space, further increasing the danger of the beam 10. The beam absorber plate 7 easily absorbs the light beam 10 that is not irradiated onto the substrate 40, which can greatly improve the safety of the maskless lithography equipment.

[0059] In one embodiment of this application, in the longitudinally and transversely distributed micromirror units 31, the connecting lines between each row of micromirror units 31 are configured to be parallel to the plane on which the substrate 40 is located.

[0060] Since the included angle between the first direction 111 and the second direction 112 in the various embodiments of this application is achieved by configuring the substrate 40 and the stage assembly 4, the connecting lines between each row of micromirror units 31 can be configured to be parallel to the plane of the substrate 40. In this way, when setting up the digital micromirror device 3, it is only necessary to configure the digital micromirror device 3 to selectively reflect the beam 10 emitted from the beam expander 2 to the projection lens 5, without having to consider the direction of the connecting lines between the light spots formed after reflection when setting the orientation of the digital micromirror device 3. This simplifies the orientation relationship of each optical element of the maskless lithography equipment, thereby simplifying the installation and debugging of the maskless lithography equipment.

[0061] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A maskless photolithography apparatus, characterized in that, The system includes an illumination device for generating area array light, a digital micromirror device disposed in the optical path of the area array light emitted by the illumination device, a stage assembly for supporting a substrate to be processed, a projection lens disposed between the stage assembly and the digital micromirror device, and a control unit electrically connecting the stage assembly and the digital micromirror device. The digital micromirror device has multiple longitudinally and transversely arranged micromirror units. The area array light reflected by the micromirror units forms etching spots on the substrate after passing through the projection lens. Each etching spot is longitudinally and transversely arranged along a first direction and a direction perpendicular to the first direction, and the etching spots are capable of scanning and irradiating the substrate along a second direction. The included angle θ between the directions is an acute angle; wherein, when it is necessary to print circuit lines on the substrate with a width not equal to an integer multiple of the diameter of the etched spot, the control unit controls multiple longitudinally and transversely arranged micromirror units of the digital micromirror device to reflect the light beam onto the substrate according to a preset timing relationship, and scans a line with a width equal to a[1±(n-1)sinθ] on the substrate, where a represents the diameter of the etched spot, and n is the number of adjacent micromirror units in the first orientation in the first direction; by setting the exposure threshold through the control unit and controlling the exposure time, the area of ​​repeated exposure reaches the threshold, causing the photosensitive dry film to undergo a physicochemical reaction, so as to realize the continuous variability of the circuit lines on the substrate.

2. The maskless photolithography equipment as described in claim 1, characterized in that, The stage assembly includes a stage body and a movable platform connected to the stage body; the substrate is disposed on the side of the movable platform facing the projection lens, and the movable platform can drive the substrate to move under the control of the control unit.

3. The maskless lithography equipment as described in claim 2, characterized in that, The substrate includes a first bottom surface that contacts the moving platform, a second bottom surface that is opposite to the first bottom surface and faces the projection lens, and a first side surface that connects the periphery of the first bottom surface and the second bottom surface; the first side surface is parallel to the first direction, and the moving platform can drive the substrate to move along the second direction.

4. The maskless lithography apparatus as described in any one of claims 1-3, characterized in that, The digital micromirror device further includes a digital micromirror motherboard that carries each of the micromirror units, and a digital micromirror power supply that is electrically connected to the digital micromirror motherboard and is used to supply power to the digital micromirror motherboard; each of the micromirror units is arranged longitudinally and laterally on the side of the digital micromirror motherboard opposite to the lighting device; the digital micromirror motherboard can be connected to the control unit, and the digital micromirror motherboard can drive each of the micromirror units to switch between a first posture, a second posture, and a third posture under the control of the control unit.

5. The maskless lithography equipment as described in claim 4, characterized in that, The maskless lithography equipment also includes a beam absorption plate, which is disposed on the optical path of the array light after the digital micromirror device when the micromirror unit is in the second and third postures.

6. The maskless lithography apparatus as described in claim 4, characterized in that, The digital micromirror device has 1080 rows and 1920 columns of micromirror units arranged in a horizontal and vertical manner, and the distance between adjacent micromirror units is 10.8 μm; or, the digital micromirror device has 1600 rows and 2560 columns of micromirror units arranged in a horizontal and vertical manner, and the distance between adjacent micromirror units is 7.56 μm.

7. The maskless lithography apparatus as described in claim 4, characterized in that, In the longitudinally and transversely distributed micromirror units, the lines connecting each row of micromirror units are configured to be parallel to the plane on which the substrate is located.

8. The maskless lithography apparatus according to any one of claims 1-3, characterized in that, The illumination device includes a laser generator for emitting laser light to the digital micromirror device, and a beam expander disposed between the laser generator and the digital micromirror device.

9. A maskless photolithography method, applicable to the maskless photolithography equipment as described in any one of claims 1-8, characterized in that, The maskless photolithography method includes the following steps: The substrate is placed on the stage assembly; The lighting device starts working and generates the area array light. The area array light is projected onto the substrate through the digital micromirror device and the projection lens, and the etching spot is arranged longitudinally and laterally along the first direction and the direction perpendicular to the first direction. The control unit controls the stage assembly to move the substrate along the second direction. At the same time, the control unit controls the deflection state of each micromirror unit according to the pattern formed by photolithography on the substrate as needed. This step is repeated until a preset photolithography pattern is formed on the substrate.

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