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 method. The device comprises an illumination device, a digital micromirror device arranged on the light path of the illumination device, a stage assembly for carrying a substrate, a projection objective arranged between the stage assembly and the digital micromirror device, and a control unit. The digital micromirror device has a plurality of micro-mirror units arranged in a longitudinal and lateral manner. The surface 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 substrate comprises a first bottom surface in contact with the stage assembly, a second bottom surface opposite to the first bottom surface and facing the projection objective, and a first side surface parallel to the second direction, and the stage assembly can drive the substrate to move along the first direction. The control unit controls the deflection of the micro-mirror units, and 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 in which a photosensitive dry film is attached to the substrate, when the intensity of the laser irradiated onto the photosensitive dry film is higher than a threshold value, the photosensitive dry film receives the laser and undergoes a chemical reaction, adsorbing onto the substrate. Further, by controlling the flipping state of the DMD and scanning on the substrate, the photosensitive dry film at each location on the substrate can receive laser irradiation of different intensities, exposing a circuit pattern 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, which cannot achieve continuous variation of the circuit width. SUMMARY

[0005] The present application aims 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 a 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 in 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, the angle θ between the first direction and the second direction is an acute angle; the substrate comprises a first bottom surface in contact with the stage assembly, 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 second direction, and the stage assembly can move the substrate along the first direction.

[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 move the substrate under the control of the control unit.

[0008] In an embodiment of the application, the digital micro-mirror device further comprises a digital micro-mirror mainboard carrying each micro-mirror unit, and a digital micro-mirror power supply electrically connected to the digital micro-mirror mainboard and used for supplying power to the digital micro-mirror mainboard; each micro-mirror unit is arranged in a matrix on the side of the digital micro-mirror mainboard opposite to the illuminating device, the digital micro-mirror mainboard can be connected to the control unit, and the digital micro-mirror mainboard 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.

[0009] In an embodiment of the application, the maskless lithography device further comprises a light beam absorption plate arranged in the light path of the planar array of light after passing through the digital micro-mirror device when the micro-mirror units are in the second posture and the third posture.

[0010] In an embodiment of the application, the digital micro-mirror device has 1080 rows and 1920 columns of micro-mirror units arranged in a matrix, and the distance between adjacent micro-mirror units is 10.8 μm; or, the digital micro-mirror device has 1600 rows and 2560 columns of micro-mirror units arranged in a matrix, and the distance between adjacent micro-mirror units is 7.56 μm.

[0011] In one embodiment of the present application, the connecting lines between the micro-mirror units in each row are configured to be parallel to the plane in which the substrate lies.

[0012] In one embodiment of the present application, the illumination device comprises a laser generator for emitting laser light to the DMD, and a beam expander arranged between the laser generator and the DMD.

[0013] Another object of the present application is to provide a maskless lithography method suitable for the maskless lithography device as described above, the maskless lithography method comprising the following steps:

[0014] placing the substrate on the stage assembly;

[0015] The illumination device starts to work and generates the surface array light, the surface array light passes through the DMD and the projection objective to project the etching light spot on the substrate, the etching light spots are arranged in a longitudinal and transverse manner along the first direction and the direction perpendicular to the first direction;

[0016] The control unit controls the stage assembly to move the substrate along the first direction, and controls the deflection state of each micro-mirror unit according to the new pattern formed after the deflection angle θ of the pattern formed by the lithography on the substrate, and the step is repeated until the preset lithography pattern is formed on the substrate.

[0017] Implementing the maskless lithography device provided by any one of the embodiments of the present application has at least the following beneficial effects:

[0018] The exposure light beam output by the illumination device sequentially passes through the beam expander, the DMD and the projection objective to form the etching light spot on the substrate, the etching light spots formed by each micro-mirror unit are arranged in a longitudinal and transverse manner along the first direction and the direction perpendicular to the first direction, under the control of the control unit, the etching light spot can scan and irradiate the substrate along the 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 micro-mirror units arranged in a longitudinal and transverse manner of the DMD to deflect according to the preset time sequence relationship, and reflect the light beam to the substrate, and finally can scan the circuit line with a width not equal to an integer multiple of the diameter of the etching light spot on the substrate, so that the width of the printed circuit on the substrate has continuous variability.

[0019] In the setting of the digital micromirror device, only the digital micromirror device is configured to selectively reflect the planar array light to the projection objective, without considering the direction of the connecting line between the light spots formed after the reflection of the digital micromirror device when setting the posture of the digital micromirror device, so as to simplify the posture relationship of each optical element of the maskless lithography equipment, thereby simplifying the installation and debugging work of the maskless lithography equipment. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0021] Figure 1 is a structural schematic diagram of a maskless lithography equipment provided by an embodiment of the present application;

[0022] Figure 2 is a working principle schematic diagram of a maskless lithography equipment provided by an embodiment of the present application;

[0023] Figure 3 is a working principle schematic diagram of a digital micromirror device provided by an embodiment of the present application.

[0024] The label details involved in the above drawings are as follows:

[0025] 1-illumination device; 10-light beam; 11-etching spot; 111-first direction; 112-second direction; 2-beam expander; 3-digital micromirror device; 31-micro-mirror unit; 32-digital micromirror mainboard; 4-objective table assembly; 40-substrate; 401-first side; 402-second side; 403-third side; 404-fourth side; 5-projection objective; 6-control unit; 7-light beam absorption plate. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present application more clear, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0027] It should be noted that when a component is referred to as being "fixed" or "set" on another component, it can be directly or indirectly on the other component. When a component is referred to as being "connected" to another component, it can be directly or indirectly connected to the other component. The terms "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or position shown in the drawings based on the orientation or position shown in the drawings, and are only for the convenience of description, and cannot be understood as a limitation on the technical solutions. The terms "first", "second" are only for the convenience of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. The meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0028] In order to illustrate the technical solutions described in the present application, the following will be described in detail in combination with specific drawings and examples.

[0029] Please refer to Figure 1 and Figure 2 , one embodiment of the present application provides a maskless lithography device, which comprises an illuminating device 1 for generating a planar array of light, a digital micromirror device 3 arranged in the light path of the planar array of light beam 10 emitted by the illuminating device 1, a stage assembly 4 for carrying a substrate 40 to be processed, a projection objective 5 arranged between the stage assembly 4 and the digital micromirror device 3, and a control unit 6 electrically connected to the stage assembly 4 and the digital micromirror device 3; the digital micromirror device 3 has a plurality of micro-mirror units 31 arranged in a longitudinal and horizontal manner, the planar array of light reflected by the micro-mirror units 31 forms etching light spots 11 on the substrate 40 after passing through the projection objective 5; each etching light spot 11 is arranged in a longitudinal and horizontal manner along a first direction 111 and a direction perpendicular to the first direction 111, and the etching light spot 11 can scan and irradiate the substrate 40 along a second direction 112, the included angle θ between the first direction 111 and the second direction 112 is an acute angle; the substrate 40 comprises a first bottom surface in contact with the stage assembly 4, a second bottom surface opposite to the first bottom surface and facing the projection objective 5, and a first side surface 401 connecting the first bottom surface and the second bottom surface; the first side surface 401 is parallel to the second direction 112, that is, the included angle between the first side surface 401 and the first direction 111 is θ, and the stage assembly 4 can drive the substrate 40 to move along the first direction 111.

[0030] Please refer to Figure 1 and Figure 3As a specific solution of the embodiment, the PCB can be rectangular, further comprising 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 parallel to the second direction 112, and correspondingly, the second side 402 and the fourth side 404 are perpendicular to the second direction 112. The moving platform drives the substrate 40 to move along the first direction 111. The control unit 6 controls the multiple longitudinal and lateral arrangement of the micro-mirror units 31 of the digital micro-mirror device 3 to reflect the light beam 10 to the substrate 40 in time sequence while the moving platform drives the substrate 40 to move, so as to scan a line with continuous variability in width on the substrate 40 according to the circuit to be printed on the substrate 40.

[0031] Specifically, the maskless lithography device provided by the embodiment works as follows:

[0032] Referring to Figure 1 and Figure 2 , the area array light emitted by the illumination device 1 irradiates the digital micro-mirror device 3; the digital micro-mirror device 3 has multiple longitudinal and lateral arrangement of the micro-mirror units 31, each of which can switch between three deflection postures (i.e. a first posture, a second posture and a third posture) under the control of the control unit 6. When the micro-mirror unit 31 is in the first posture, the area array light emitted by the illumination device 1 will irradiate the projection objective 5 after being reflected by the micro-mirror unit 31, and be imaged on the substrate 40 by the projection objective 5. In this way, the photosensitive dry film can be pasted on the substrate 40, so that when the intensity of the area array light irradiating the photosensitive dry film is higher than the threshold value, the photosensitive dry film will receive the area array light and undergo a chemical reaction, and be adsorbed on the substrate 40; further, the control unit 6 controls the flipping state of the micro-mirror units 31 of the digital micro-mirror device 3, and controls the digital micro-mirror device 3 to scan on the substrate 40, so that the photosensitive dry film at each position on the substrate 40 receives irradiation of area array light with different intensities, and exposes a circuit diagram on the substrate. More specifically, the control unit 6 rotates the circuit to be printed on the substrate 40 by an angle θ as the final circuit to be printed on the substrate 40 according to the circuit to be printed on the substrate 40; while the moving platform drives the substrate 40 to move, the control unit 6 controls the multiple longitudinal and lateral arrangement of the micro-mirror units 31 of the digital micro-mirror device 3 to reflect the area array light to the substrate 40 in time sequence, so as to scan a line with continuous variability in width on the substrate 40.

[0033] As a specific solution of the embodiment, the illumination device 1 comprises a laser generator 1 for emitting a light beam 10 to the digital micro-mirror device 3, and a beam expander 2 arranged between the laser generator 1 and the digital micro-mirror device 3. The light beam 10 output by the laser generator 1 is first expanded and collimated by the beam expander 2 into a planar array of light beams 10 and irradiated to the digital micro-mirror device 3, and after being selectively reflected by the digital micro-mirror device 3 and refracted by the projection objective 5, forms the etching light spots 11 constituting an array on the substrate 40. More preferably, the illumination device 1 further comprises a shaping mirror (not shown in the figure) arranged between the beam expander 2 and the digital micro-mirror device 3, which is used to change the wavefront of the light beam 10 and shape the light beam 10 expanded by the beam expander 2 into a planar array of light beams with uniform wavefront intensity, so that the light intensity of each etching light spot 11 is closer.

[0034] The maskless photoetching device provided by the embodiment has at least the following beneficial technical effects:

[0035] The planar array of light beams emitted by the illumination device 1 forms the etching light spots 11 on the substrate 40 after passing through the digital micro-mirror device 3 and the projection objective 5 in turn, and the etching light spots 11 formed by each micro-mirror unit 31 are arranged longitudinally and transversely along the first direction 111 and the direction perpendicular to the first direction 111, forming a matrix of etching light spots 11. Under the control of the control unit 6, the etching light spots 11 can scan and irradiate the substrate 40 along the second direction 112, and the included 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 micro-mirror units 31 of the digital micro-mirror device 3 to deflect according to a preset timing relationship, and the planar array of light beams is reflected to the substrate 40, so that a line with a width that is not equal to an integer multiple of the diameter of the etching light spot 11 can be scanned on the substrate 40, and the printed line on the substrate 40 has continuous variability.

[0036] When the digital micro-mirror device 3 is arranged, it is only necessary to configure the digital micro-mirror device 3 to selectively reflect the planar array of light beams coming from the beam expander 2 to the projection objective 5, without considering the direction of the connecting line between the light spots formed after reflection by the digital micro-mirror device 3 when the posture of the digital micro-mirror device 3 is arranged, so that the posture relationship of each optical element of the maskless photoetching device can be simplified, and the installation and debugging work of the maskless photoetching device can be simplified.

[0037] Please refer to Figure 1 and Figure 2In particular, the etching spots 11 formed by the micro-mirror units 31 are arranged in a longitudinal and lateral direction, and the etching spots 11 can be controlled to scan the substrate 40 in the first direction 111 under the control of the control unit 6; the first side of the substrate 40 is parallel to the second direction 112, and the included angle θ between the first direction 111 and the second direction 112 is an acute angle, so that when the circuit line with a width not equal to an integer multiple of the diameter of the etching spot 11 needs to be printed on the substrate 40, the control unit 6 can control the plurality of longitudinal and lateral arranged micro-mirror units 31 of the digital micro-mirror device 3 to reflect the light beam 10 to the substrate 40 according to a preset time sequence relationship, so as to scan 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 micro-mirror units 31 in the first direction 111 in the first state). By setting the included angle θ between the first direction 111 and the second direction 112, setting the exposure threshold value by the control unit, controlling the exposure time, and making the repeatedly exposed area reach the threshold value, the chemical reaction of the photosensitive dry film is realized, so as to realize the continuous variability of the circuit line on the substrate 40.

[0038] For example, when θ is set to 30°, the basic unit size of the etching spot 11 is 1x1 μm (i.e., the minimum exposure line width is 1 um), but when a 1.5 μm wide circuit line is actually needed, the intensity of the light beam 10 can be set to be equal to 1 times the threshold value, i.e., the irradiation of one etching spot 11 has sufficient light intensity to cause the photosensitive dry film to chemically react and be adsorbed on the substrate 40, so that when one etching spot 11 scans the surface of the substrate 40 in the first direction 111, the scanning point advances 1 μm, i.e., a spot is left on the substrate, and since the mesa has an included angle θ, the etching spot 11 is located at a position deviated from the included angle θ perpendicular to the first direction 111, and the etching spot 11 adjacent to the etching spot 11 starts to irradiate, and so on, so that a 1.5 μm wide circuit line can be etched on the surface of the substrate 40; when a 0.5 μm wide circuit line is actually needed, the diameter of the etching spot 11 is 1 μm, and the intensity of the light beam 10 can be set to be equal to 0.5 times the threshold value, i.e., the irradiation of two etching spots 11 has sufficient light intensity to cause the photosensitive dry film to chemically react and be adsorbed on the substrate 40, and the same scanning method as the above method can be used, so that a 0.5 μm wide circuit line can be etched on the surface of the substrate 40.

[0039] More specifically, taking the case where the diameter of the etching spot 11 is 1 μm, but the circuit line actually required is 1.5 μm wide, and θ is 30°, for example, at this time, the intensity of the light beam 10 is configured to be sufficient for the single etching spot 11 to cause the photosensitive dry film to undergo a chemical reaction and be adsorbed to the substrate. When the substrate 40 is moved to a position where the first column of etching spots 11 (in the principle description of the present embodiment, the etching spots 11 distributed in a direction parallel to the first direction 111 are a column, and the etching spots 11 distributed in a direction perpendicular to the first direction 111 are a row) irradiate the position to be etched, the control unit 6 controls the micro-mirror unit 31 corresponding to the position to be etched in the first column to flip, thereby etching a first region having a width of 1 μm at the position to be etched of the substrate 40. The etching spot 11 continues to move in the first direction 111, and after the etching spot 11 of the first column has traveled 1 μm, the irradiation of the previous region is stopped, and the irradiation of the next row is performed, and at the same time, the etching spot 11 of the second column adjacent to the etching spot 11 of the first column starts to irradiate the position to be etched, the control unit 6 controls the micro-mirror unit 31 corresponding to the position to be etched in the second column (that is, a micro-mirror unit 31 in the second column that is in the same row as the micro-mirror unit 31 of the first column that has been flipped and etched a circuit) to flip, thereby etching a second region having a width of 1 μm at the position to be etched of the substrate 40. This cycle is repeated until a linear exposure region is formed on the substrate 40. Since there is a 30° angle between the second direction 112 and the first direction 111, the linear exposure region has a width of 1.5 μm when viewed in the second direction 112.

[0040] For example, the diameter of the etching spot 11 is 1 μm, but the actual width of the circuit required is 0.5 μm, and the angle θ is 30°. In this case, the intensity of the light beam 10 is configured to be sufficient to cause the photosensitive dry film to undergo a chemical reaction and be adsorbed on the substrate only when the two etching spots 11 are superimposed. When the substrate 40 is moved to a position where the etching spot 11 of the first column (in the principle description of the present embodiment, the etching spots 11 distributed in a direction parallel to the first direction 111 are a column, and the etching spots 11 distributed in a direction perpendicular to the first direction 111 are a row) irradiates the position to be etched, the control unit 6 controls the micro-mirror units 31 of the first row corresponding to the position to be etched to flip, so as to project a light spot with a diameter of 1 μm on the position to be etched of the substrate 40. The etching spot 11 continues to move along the first direction 111, and after the etching spot 11 of the first column travels 1 μm, the irradiation of the previous area is stopped, and the irradiation of the next row is performed. At the same time, the etching spot 11 of the second column adjacent to the etching spot 11 of the first column starts to irradiate the position to be etched, the control unit 6 controls the micro-mirror units 31 of the second column corresponding to the position to be etched (i.e., a micro-mirror unit 31 of the second column which is in the same row as the micro-mirror units 31 of the first column which have been flipped and etched the circuit) to flip, so as to project a light spot with a diameter of 1 μm on the position to be etched of the substrate 40. The above process is repeated until a line-shaped exposure area is formed on the substrate 40. Since there is an angle θ between the platform and the first direction 111, i.e., there is an angle θ between the second direction and the first direction 111, the width of the line-shaped exposure area is 0.5 μm as viewed along the second direction 112 (perpendicular to the substrate direction).

[0041] In actual operation, the value of θ is usually in the range of 5° to 15°. Moreover, the circuit to be etched on the substrate 40 is very complex, and the control unit 6 can control the digital micro-mirror device 3 to change the state of the micro-mirror units 31 in real time, and repeatedly perform the process of transmitting the etching spot 11 to the substrate 40 and scanning multiple times to achieve multiple exposures or repeated exposures, so as to etch the required circuit pattern on the substrate 40.

[0042] In an embodiment of the present application, the stage assembly 4 includes a stage body and a moving platform connected to the stage body. The substrate 40 is arranged on the side of the moving platform opposite the projection objective 5, and the moving platform can drive the substrate 40 to move under the control of the control unit 6.

[0043] Please refer to Figure 1 and Figure 2 . Specifically, when the control unit 6 controls the moving platform to drive the substrate 40 to move, the control unit 6 also controls the deflection state of each micro-mirror unit 31 of the digital micro-mirror device 3 according to the specific pattern of the circuit diagram drawn on the substrate 40, so as to draw a complex and continuously variable width circuit on the substrate 40.

[0044] As a specific solution of the embodiment, the stage body and the moving platform are connected through a track, the stage assembly 4 further comprises a motor for driving the movement of the moving platform, and a support for supporting the output of the laser generator 1, the beam expander 2, the digital micro-mirror device 3 and the projection objective 5, the support is connected to the stage body, and the projection objective 5 connected to the support is arranged opposite to the moving platform.

[0045] Please refer to Figure 3 In an embodiment of the present application, the first, second and third attitudes of the micro-mirror unit 31 are -12°, 0° and +12° respectively, the output of the laser generator 1 is arranged horizontally, and after the digital micro-mirror device 3 is arranged along a direction perpendicular to the light beam 10, the upper part of the digital micro-mirror device 3 is rotated by 33° towards the position where the laser generator 1 is located, so that when the micro-mirror unit 31 in the digital micro-mirror device 3 is in the first attitude, the corresponding light beam 10 can be reflected to the projection objective 5 and form the etching spot 11 on the substrate 40.

[0046] In the conventional solution, the digital micro-mirror device 3 needs to be further rotated along the axis of the reflecting surface of the digital micro-mirror device 3, and in this process, the connecting lines between the plurality of etching spots 11 projected on the substrate 40 after being reflected by the digital micro-mirror device 3 are generally parallelogram-shaped, which is undoubtedly not conducive to the control of the control unit 6 circuit printing, greatly increases the complexity of the control program, and thus often requires more complex debugging of the attitude of the digital micro-mirror device 3, so that the connecting lines between the plurality of etching spots 11 are generally rectangular, and the installation and debugging work of the maskless lithography equipment is complex and tedious.

[0047] Corresponding to the embodiment, the present application provides a maskless lithography method, the maskless lithography method comprising the following steps:

[0048] The substrate 40 is placed on the stage assembly 4;

[0049] The illumination device 1 starts to work and generates a planar array light, the planar array light projects the etching spot 11 on the substrate 40 through the digital micro-mirror device 3 and the projection objective 5, and the etching spot 11 is arranged longitudinally and transversely along the first direction 111 and the direction perpendicular to the first direction 111;

[0050] The control unit 6 controls the stage assembly 4 to move the substrate 40 along the first direction 112, and at the same time, the control unit 6 controls the deflection state of each micro-mirror unit 31 according to the new pattern formed after the deflection angle θ of the pattern formed by the photolithography on the substrate 40, and the step is repeated until the preset photolithography pattern is formed on the substrate 40.

[0051] The maskless lithography method provided by the embodiment can project the etching light spot 11 arranged in the first direction 111 and the direction perpendicular to the first direction 111 on the substrate 40 through the illumination device 1, and drive the substrate 40 to move along the first direction 111 through the stage assembly 4, and arrange the first side of the substrate 40 along the second direction 112, so as to etch the complex and continuously variable width circuit on the substrate 40 in the way of multiple exposure and repeated exposure, thereby realizing the continuous variability of the circuit on the substrate 40. The control unit 6 controls the stage assembly 4 to drive the substrate 40 to move along the first direction 111, so that when the digital micromirror device 3 is arranged, only the digital micromirror device 3 is arranged to selectively reflect the surface array light from the beam expander 2 to the projection objective 5, without considering the direction of the connecting line between the light spots formed after the reflection of the digital micromirror device 3 when the posture of the digital micromirror device 3 is arranged, so as to simplify the posture relationship of each optical element of the maskless lithography equipment and the installation and debugging work of the maskless lithography equipment.

[0052] As a specific scheme of the embodiment, the illumination device 1 includes a laser generator 1 arranged opposite to the digital micromirror device 3, and a beam expander 2 arranged between the laser generator 1 and the digital micromirror device 3. The light beam 10 generated by the laser generator 1 becomes surface array light after being expanded by the beam expander 2. The surface array light is projected to the substrate 40 through the digital micromirror device 3 and the projection objective 5 to project the etching light spot 11.

[0053] In an embodiment of the present application, the digital micromirror device 3 further includes a digital micromirror main plate 32 carrying each micro-mirror unit 31, and a digital micromirror power supply electrically connected with the digital micromirror main plate 32 and used for supplying power to the digital micromirror main plate 32. Each micro-mirror unit 31 is arranged in a longitudinal and horizontal manner on the side of the digital micromirror main plate 32 opposite to the beam expander 2. The digital micromirror main plate 32 can be connected with the control unit 6, and the digital micromirror main plate 32 can drive each micro-mirror unit 31 to switch between the first posture, the second posture and the third posture under the control of the control unit 6.

[0054] More specifically, the digital micromirror main plate 32 includes a light-reflecting main plate for carrying each micro-mirror unit 31 and a control main plate for electrically connecting with the control unit 6. The light-reflecting main plate and the control main plate are connected through a cable, and the light-reflecting main plate is provided with a DMD chip for controlling each micro-mirror unit 31. The digital micromirror power supply is used for supplying power to the control main plate and the light-reflecting main plate. The control unit 6 is installed with corresponding program control software, which can control the rotation of each micro-mirror unit 31 on the digital micromirror device 3 by outputting the coded signal to the digital micromirror unit, so as to selectively reflect the etching light spot 11 to the projection objective 5.

[0055] In an embodiment of the present application, the digital micro-mirror device 3 has 1080 rows and 1920 columns of micro-mirror units 31 arranged in a vertical and horizontal manner, or has 1600 rows and 2560 columns of micro-mirror units 31 arranged in a vertical and horizontal manner, and the distance between adjacent micro-mirror units 31 is 10.8 μm or 7.56; more specifically, the angle θ between the first direction 111 and the second direction 112 ranges from 5° to 15°. In this way, the 1920*1080 resolution or 1600*2560 resolution of the light beam 10 can be etched, and through further imaging by the projection objective 5, the area of the etching spot 11 can be reduced to the nanometer level, thereby reducing the diameter of the etching spot 11, so that the maskless lithography device has a smaller minimum line width and improves the etching precision of the light beam 10.

[0056] Referring to Figure 1 In an embodiment of the present application, the maskless lithography device further comprises a light beam absorption plate 7, which is arranged on the light path of the light beam 10 after the digital micro-mirror device 3 when the micro-mirror units 31 are in the second and third positions.

[0057] The purpose of arranging the light beam absorption plate 7 is to absorb the light beam 10 that is reflected by the micro-mirror units 31 but is not irradiated on the substrate 40. In the light beam 10 etching operation, a high-energy laser generator 1 is often used to ensure that the photosensitive dry film can undergo a chemical reaction after being irradiated by the light beam 10. In addition to the intensity of the light beam 10 irradiated on the photosensitive dry film needing to be higher than the threshold value, the wavelength of the light beam 10 should also be short enough to ensure that a single photon has enough energy to cause the photosensitive dry film to undergo a chemical reaction. Therefore, the light beam 10 has a high-energy characteristic in the light beam 10 etching operation. Moreover, each micro-mirror unit 31 has a first position, a second position and a third position, and the etching light beam 10 that is not reflected to the substrate 40 is reflected to other two specific directions in space, which further increases the risk of the light beam 10. Arranging the light beam absorption plate 7 can easily absorb the light beam 10 that is not irradiated on the substrate 40, thereby greatly improving the safety of the maskless lithography device.

[0058] In an embodiment of the present application, in the vertical and horizontal arrangement of the micro-mirror units 31, the connecting line between each row of micro-mirror units 31 is arranged to be parallel to the plane in which the substrate 40 is located.

[0059] Since the included angle between the first direction 111 and the second direction 112 in each embodiment of the present application is achieved by configuring the substrate 40 and the stage assembly 4, the connection line between each row of the micro-mirror units 31 can be configured to be parallel to the plane in which the substrate 40 is located. In this way, when the digital micro-mirror device 3 is arranged, it is only necessary to configure the digital micro-mirror device 3 to selectively reflect the light beam 10 to the projection objective 5, without considering the direction of the connection line between the light spots formed after reflection by the digital micro-mirror device 3 when setting the posture of the digital micro-mirror device 3, thereby simplifying the posture relationship of each optical element of the maskless lithography equipment, and thereby simplifying the installation and debugging work of the maskless lithography equipment.

[0060] The above only describes optional embodiments of the present application and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A maskless lithography apparatus, characterized by, The maskless lithography device comprises an illumination device for generating a planar light array, a digital micro-mirror device arranged in the light path of the planar light array emitted by the illumination 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, and the planar light array 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 angle θ between the first direction and the second direction is an acute angle; when it is required to print a circuit line with a width not equal to an integer multiple of the diameter of the etching spot on the substrate, the control unit controls the plurality of micro-mirror units of the digital micro-mirror device to reflect light beams onto the substrate according to a preset time sequence relationship, and scans a line with a width equal to a[1±(n-1)sinθ] on the substrate, wherein a represents the diameter of the etching spot, and n is the number of micro-mirror units in a first state adjacent in the first direction; the control unit sets an exposure threshold value and controls the exposure time, so that the repeatedly exposed area reaches the threshold value, and the photosensitive dry film undergoes a chemical reaction, thereby realizing the continuous variability of the circuit line on the substrate. The substrate comprises a first bottom surface in contact with the stage assembly, 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 second direction, and the stage assembly can move the substrate along the first direction.

2. The maskless lithography apparatus of claim 1, wherein, 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 move the substrate under the control of the control unit.

3. A maskless lithography apparatus according to any one of claims 1 or 2, wherein, 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 illumination 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 state, a second state and a third state under the control of the control unit.

4. The maskless lithography apparatus of claim 3, wherein, The maskless lithography device further comprises a light beam absorption plate arranged in the light path of the planar light array after passing through the digital micro-mirror device when the micro-mirror unit is in the second state and the third state.

5. The maskless lithography apparatus of claim 3, wherein, The digital micro-mirror device has 1080 rows and 1920 columns of the micro-mirror units arranged in a matrix, and the distance between adjacent micro-mirror units is 10.8 μm; or the digital micro-mirror device has 1600 rows and 2560 columns of the micro-mirror units arranged in a matrix, and the distance between adjacent micro-mirror units is 7.56 μm.

6. The maskless lithography apparatus of claim 3, wherein, The connection lines between the micro-mirror units in the matrix are configured to be parallel to the plane on which the substrate is located.

7. The maskless lithography apparatus of any one of claims 1 or 2, wherein, The illumination device comprises a laser generator for emitting laser light to the digital micro-mirror device, and a beam expander arranged between the laser generator and the digital micro-mirror device.

8. A maskless lithography method, suitable for use in a maskless lithography apparatus as claimed in any one of the claims 1-7, characterized in that, The maskless lithography method comprises the following steps: The substrate is placed on the stage assembly; The illumination device starts to work and generates the surface array light, the surface array light passes through the digital micro-mirror device and the projection objective lens to project the etching light spot on the substrate, and the etching light spot is arranged in a matrix 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 first direction, and controls the deflection state of each micro-mirror unit according to the new pattern formed after the deflection angle θ of the pattern formed by lithography on the substrate, and the step is repeated until the preset lithography pattern is formed on the substrate.

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