Method and apparatus for manufacturing three-dimensional component based on lithographic generation

Abstract

In a method for producing a three-dimensional component on the basis of lithographic generation, a beam is divided into a plurality of beams by means of a beam splitter (9), which are focused on a focal point in a material (2) by means of an optical imaging unit (13), the focal point being adjusted by means of a deflection unit (5, 19) arranged upstream of the optical imaging unit (13) in the beam direction, a spatial light modulator (11) having a plurality of electronically controllable pixels is provided, in which the volume elements of material are solidified by means of multi-photon absorption in sequence at the focal point of each beam, the electronically controllable pixels are scanned by a plurality of beams and are individually switched between at least one open and one closed state depending on the geometry of the component to be achieved in such a way that the respective beams are guided to the imaging unit (13) only in the at least one open state.

Description

Technical Field

[0001] The present invention relates to a method for producing three-dimensional components based on lithography, wherein a beam emitted by an electromagnetic radiation source is divided into a plurality of beams by means of a beam splitter, the plurality of beams are focused onto a focal point within a material by means of an optical imaging unit, and the focal point is shifted by means of a deflection unit arranged upstream of the optical imaging unit in the beam direction, thereby successively solidifying volume elements of the material located at the focal point by means of multiphoton absorption.

[0002] The invention further relates to a device for producing three-dimensional components based on photolithographic generation. Background Art

[0003] For example, DE 10111422 A1 discloses a method for forming a component in which a photosensitive material is cured by means of multiphoton absorption. To this end, a bath of the photosensitive material is irradiated with a focused laser beam, wherein the irradiation conditions for triggering the multiphoton absorption process for curing are met only in the immediate vicinity of the focus, so that the focus of the beam is directed within the bath volume to the location to be cured, depending on the geometrical data of the molded body to be produced.

[0004] In this case, the volume elements of the material are solidified at the respective focal points, wherein adjacent volume elements adhere to one another and the component is built up by the sequential solidification of adjacent volume elements. When building up the component, it is possible to proceed layer by layer, i.e. first solidify the volume elements of the first layer and then solidify the volume elements of the next layer.

[0005] The irradiation device for the multiphoton absorption method comprises an optical device for focusing the laser beam and a deflection device for deflecting the laser beam. In this case, the deflection device is designed to focus the beam successively onto focal points in the material, which are located in the same plane, and the plane preferably extends perpendicularly to the direction of incidence of the beam into the material. In the x, y, z coordinate system, the plane is also called the x, y plane. The solidified volume elements formed by the beam deflection in the x, y plane constitute a layer of the component. In order to achieve continuous operation of the deflection device, the beam is interrupted or switched off and connected again between the solidification of two consecutive volume elements.

[0006] To build up the next layer, the relative position of the focusing optics relative to the component is changed in the z direction, which corresponds to the direction of incidence of the at least one beam into the material and extends perpendicularly to the x,y plane. By adjusting the focusing optics relative to the component, which is usually carried out by a motor, the focus is shifted into a new x,y plane, which is spaced apart from the previous x,y plane in the z direction by the desired layer thickness.

[0007] Structuring suitable materials by means of multiphoton absorption offers the advantage of extremely high structural resolution, with volume elements with minimum structural dimensions down to 50 nm × 50 nm × 50 nm being achievable. However, due to the small focal volume, the throughput of this method is very low, since, for example, for a 1 mm 3 The volume must be exposed for a total of more than 10 9 This results in very long build times, which is the main reason for the low industrial application rate of multiphoton absorption methods.

[0008] In order to increase the throughput of a component without sacrificing the possibility of high structural resolution, it has been proposed to change the volume of the focus at least once during the component construction so that the component is constructed from solidified volume elements of different volumes. Due to the variable volume of the focus, high resolution is possible (in the case of a small focus volume). At the same time, high writing speeds (in mm) can be achieved (in the case of a large focus volume). 3 / h measurement). By varying the focal volume, it is thus possible to combine high resolution with high throughput. Here, for example, a change in the focal volume can be used so that a large focal volume is used in the interior of the component to be constructed in order to increase the throughput, and a smaller focal volume is used at the component surface in order to construct the component surface with high resolution. Increasing the focal volume enables a higher structuring throughput because the volume of material that solidifies during the exposure process increases. In order to maintain high resolution at high throughput, a small focal volume can be used for finer structures and surfaces, while a larger focal volume can be used for coarse structures and / or for filling interior spaces. A method and an apparatus for varying the focal volume are described in WO 2018 / 006108 A1.

[0009] Another possibility for increasing the writing speed is to divide the writing beam into a plurality of writing beams by means of a beam splitter, each of which is focused into the material to be cured, so that a plurality of volume elements can be cured in parallel (Kelemen et al.: "Parallel photopolymerization with complex light patterns generated by diffractive optical elements", Optics Express, Vol. 15, No. 22, pp. 14488-14497). However, the individual writing beams cannot be positioned independently of one another, so that only a number of components of the same type corresponding to the number of beams can be produced.

[0010] In the field of stereolithography, it is known from US Pat. No. 5,536,467 to steer a plurality of writing beams independently of one another, wherein each writing beam is deflected by its own mirror to a corresponding position in the material to be cured. However, a disadvantage is that the deflection device comprises mechanically operated mirrors, so that the scanning speed is limited and the device shown is not suitable for curing volume elements by means of multiphoton absorption. In addition, the equipment complexity increases in proportion to the number of writing beams to be moved independently of one another. Summary of the invention

[0011] The present invention aims to further develop a method and a device for producing three-dimensional components based on photolithography, so that the writing speed (in mm) 3 / h measurement) can be further increased without restricting the geometry of the components and with low equipment expenditure.

[0012] In order to achieve the above-mentioned purpose: the first aspect of the present invention proposes in a method of the type mentioned at the beginning: a spatial light modulator with a plurality of electronically controllable pixels is provided, wherein the electronically controllable pixels are scanned by a plurality of beams and the electronically controllable pixels are individually switched between at least one on state and one off state according to the geometry to be achieved of the component, so that the corresponding beam is guided to the imaging unit only in at least one on state.

[0013] The spatial light modulator allows working with multiple beams simultaneously, more precisely with multiple beams that are deflected by means of a deflection unit to move in the same direction, and for each beam to be individually controlled whether a volume element is to be solidified at a specific location in the material by said beam. This makes it possible to write in parallel with multiple beams without each beam having to produce the same geometry and without having to provide a separate deflection device for each beam.

[0014] Instead, the deflection unit causes a common deflection of all beams, which thus sweep (scan) the pixels of the light modulator with a fixed pixel spacing. The number of pixels of the spatial light modulator corresponds to a multiple of the number of beams. Since each pixel can now be switched between an on and off state independently of the state of the other pixels, it is possible to select whether a volume element within the material corresponding to the respective pixel should be cured.

[0015] In this case, subregions of the spatial light modulator are referred to as pixels, which, when in the switched-on state, are irradiated by the radiation beam and which cause the solidification of the volume element in the material.

[0016] Here, a significant increase in the writing speed is also achieved in that, due to the large number of pixels, the sum of the switching rates of all pixels is higher than the sum of the switching rates of conventional systems, such as systems operating with the aid of an acousto-optic modulator. An acousto-optic modulator can switch the beam on and off at a rate of, for example, 50 MHz, so that 50 million volume elements can be written per second. Currently, the switching rates per pixel of the available spatial light modulators are relatively low; in the case of a two-dimensional array, the entire pixel array can change its switching state at a rate of, for example, 180 Hz. However, when multiplied by the number of pixels, an extremely high writing speed is obtained. Thus, with a corresponding scanning speed of the deflection unit, 360 megapixels can be written per second with the aid of a spatial light modulator having, for example, 2 million pixels and a switching rate of 180 Hz.

[0017] According to a preferred embodiment of the present invention, the pixels of the spatial light modulator are arranged in at least one, for example, exactly one row extending along a straight line, and the beams are separated along the straight line by means of a beam splitter so that the beams impinge on the pixel row in a manner spaced apart from each other by a plurality of pixels. Here, the beams are also deflected along the mentioned straight line by a deflection unit. For example, the beam splitter generates 50 beams, which impinge on the pixel row at intervals of 20 pixels along the straight line. Now, the deflection unit is controlled so that the 50 beams are deflected together by an angle so that the beams sweep over 20 pixels, so that at the end of the deflection movement, each pixel in the pixel row comprising 1000 pixels is illuminated.

[0018] In the simplest case, a one-dimensional spatial light modulator is used, the pixels of which are arranged in a single row. Such a light modulator is also referred to as a line modulator, wherein the line modulator can be designed, for example, as a "grating light valve", i.e. as a dynamically adjustable diffraction grating, wherein an individually controllable diffraction grating is provided for each pixel, the diffraction grating comprising, for example, tiny metal strips that can be moved up and down electrostatically. As a result, each pixel can be switched back and forth between grating function and mirror function.

[0019] In the case of a line modulator, only a beam deflection about a single axis is required. The beam deflection can be performed, for example, by an acousto-optic deflector, thereby making it possible to achieve very high deflection speeds and thus high writing speeds.

[0020] Since only volume elements of a component positioned along a straight line can be cured when using a line modulator, the component carrier or material carrier must be displaced transversely to the row relative to the optical imaging unit after each row in order to write another row.

[0021] According to another preferred embodiment of the present invention, the pixels of the spatial light modulator are arranged in a plurality of parallel rows. Such a light modulator with a two-dimensional arrangement of pixels allows: without having to adjust the component carrier or the material carrier relative to the optical imaging unit, the volume elements in the material can be solidified in a two-dimensional grid manner.

[0022] In this case, the beam is deflected about two preferably mutually perpendicular axes, wherein for the deflection about a first axis a fast scanner can be used and for the deflection about a second axis a slower scanner is sufficient, wherein the first axis corresponds to an axis orthogonal to the beam division. For example, the beam deflection about the first axis is carried out by means of a resonant scanner or a polygon scanner and the beam deflection about the second axis is carried out by means of a galvanometer scanner.

[0023] A light modulator with a two-dimensional arrangement of pixels can preferably be designed as a reflective liquid crystal microdisplay. Such a light modulator is also referred to as a "liquid crystal on silicon device" or "LCoS device".

[0024] Furthermore, the use of a spatial light modulator in the manner according to the invention allows a simple pixel-by-pixel adaptation of the radiation intensity of the beam focused into the material in order to achieve a so-called "gray scaling". A preferred embodiment of the method according to the invention provides in this context that at least one switch-on state comprises at least a first and a second switch-on state, wherein the pixels are individually switched between a switch-off state and a first switch-on state and a second switch-on state, wherein the first switch-on state and the second switch-on state produce radiation intensities at the focus that differ from one another. The gray scale function offers the advantage that the intensity of the introduced radiation can be controlled for each pixel.

[0025] This can be used to achieve a homogenization of the radiation power across all volume elements, i.e. to ensure that each volume element of the material is irradiated with the same radiation power. Adapting or reducing the radiation intensity is advantageous, for example, for volume elements that are at the reversal point of the beam deflection and can therefore be irradiated for a longer time than volume elements located in between. The same applies to volume elements or pixels that are detected twice during a scan. In this context, a preferred embodiment of the invention provides that the radiation intensity of each pixel of the spatial light modulator is adjustable and that the radiation intensity is adjusted as a function of the exposure duration of the pixel so that the volume elements receive the same radiation power. For this purpose, a suitable control unit is provided, which adjusts the radiation intensity as a function of the exposure duration.

[0026] Alternatively or additionally, the regulation of the radiation intensity can also be used to change the radiation power at the individual volume elements in order to achieve a height profile in the z direction without changing the relative position between the imaging unit and the building platform. In this context, a preferred embodiment of the invention provides that the radiation intensity of each pixel of the spatial light modulator can be regulated and the radiation intensity is regulated so that the volume elements receive radiation powers that are different from each other in order to produce volume elements with different spatial extensions, in particular different spatial extensions in the direction of incidence. The radiation power is preferably regulated by means of a suitable control unit.

[0027] The spatial light modulator is usually designed so that the incident light beam is reflected in at least one on-state of the corresponding pixel. In order to achieve a structure that is as simple as possible, which allows the spatial light modulator to be arranged between the deflection unit and the beam splitter on the one hand and the optical imaging unit on the other hand, a preferred embodiment of the present invention proposes that a plurality of beams are directed to the spatial light modulator with a polarization beam splitter inserted in the middle, the beams are reflected from the spatial light modulator through the pixels in the on-state and incident on the polarization beam splitter with the changed polarization, and the polarization beam splitter directs the beams to the optical imaging unit.

[0028] In a preferred development of the above-described structure, a mirror can be provided, wherein the spatial light modulator and the mirror are displaced so that the spatial light modulator or the mirror is selectively placed in an operating position arranged in the beam path. Thus, it is possible to switch between writing a component according to the invention using a light modulator and conventional parallel writing of similar components.

[0029] In a further development, the beam splitter can be designed as a spatial light modulator which generates a static hologram or a dynamic light modulation.

[0030] The component is preferably constructed layer by layer with layers extending in the xy plane, wherein the switch from one layer to the next includes a change in the relative position of the optical imaging unit relative to the component in the z direction extending perpendicular to the xy plane. Here, the z direction substantially corresponds to the direction of incidence of the plurality of writing beams.

[0031] A preferred method results when the material is present on a material carrier, such as in a tank, and the material is irradiated from below through the material carrier which is at least partially transparent to the radiation. In this case, the building platform can be positioned at a distance from the material carrier, and the component can be built on the building platform by solidifying the material located between the building platform and the material carrier. However, it is also possible to carry out the irradiation of the material from above as an alternative.

[0032] The principle of multiphoton absorption is used within the scope of the present invention to initiate a photochemical process in a bath of photosensitive material. Multiphoton absorption methods also include, for example, 2-photon absorption methods. As a result of the photochemical reaction, the material is caused to change to at least one other state, in which photochemical polymerization is usually caused. The principle of multiphoton absorption is based on the fact that the mentioned photochemical process only occurs in the following area of ​​the beam path, in which there is a sufficient photon density for multiphoton absorption. The highest photon density occurs in the focus of the optical imaging system, so that multiphoton absorption occurs with sufficient probability only at the focus. Outside the focus, the photon density is lower, so that the probability of multiphoton absorption outside the focus is too low to cause irreversible changes in the material through photochemical reactions. The electromagnetic radiation can pass through the material essentially unimpeded at the wavelength used, and only causes an interaction between the photosensitive material and the electromagnetic radiation at the focus. The principle of multiphoton absorption is described, for example, in Zipfel et al., “Nonlinear magic: multiphoton microscopy in the biosciences”, NATURE BIOTECHNOLOGY VOLUME 21 NUMBER 11 / 11 / 2003.

[0033] The electromagnetic radiation source can preferably be a collimated laser beam. The laser can emit one or more fixed or variable wavelengths. In particular, it is a continuous laser or a pulsed laser with a pulse length in the nanosecond, picosecond or femtosecond range. The advantage of a femtosecond pulsed laser is that the average power required for multiphoton absorption is low.

[0034] Photosensitive material is understood to be any material which is flowable or solid under structural conditions and which is converted into a second state by multiphoton absorption in the focal volume (e.g. by polymerization). The material change must be limited to the focal volume and its immediate surroundings. The change in the properties of the substance can be permanent and consist, for example, in a change from a liquid to a solid state, but can also be only temporary. Furthermore, permanent changes can also be reversible or irreversible. The change in the properties of the material does not necessarily require a complete change from one state to another, but can also be present as a mixture of the two states.

[0035] According to a second aspect of the present invention, there is provided a device for producing a three-dimensional component based on photolithography, in particular a device for performing the method according to the first aspect of the present invention, comprising a material carrier for a curable material and an irradiation device, which can be controlled to perform position-selective irradiation on the curable material by means of at least one beam, wherein the irradiation device comprises: a beam splitter for splitting an input beam into a plurality of beams, a deflection unit arranged upstream and downstream of the beam splitter on the beam path, and an optical imaging unit arranged downstream of the deflection unit and the beam splitter, so as to focus each beam sequentially on a focal point in the material, thereby being able to cure the volume elements of the material at the focal point respectively by means of multiphoton absorption. The device is characterized in that a spatial light modulator having a plurality of electronically controllable pixels is arranged between the imaging unit on one side and the beam splitter and the deflection unit on the other side, the electronically controllable pixels being able to be scanned by a plurality of beams and the electronically controllable pixels being able to be individually switched between at least one on and one off state, so that the corresponding beam is guided to the imaging unit only in at least one on state.

[0036] A diffractive optical element can be used as beam splitter, for example the 1D diffractive beam splitter MS-802-IYA or MS-304-YIY from HOLO / OR Ltd.

[0037] For example, an acousto-optic modulator, a resonant scanner, a polygon scanner, a galvanometer scanner or a combination thereof can be used as the deflection unit.

[0038] The beam splitter can be arranged before or after the deflection unit. Considering the limited angular tolerance of the beam splitter, the arrangement of the beam splitter after the deflection unit is only conceivable if the maximum deflection angle is relatively small. For larger deflection angles, it is preferred to arrange the deflection unit after the beam splitter.

[0039] According to a preferred embodiment, the spatial light modulator has a one-dimensional pixel arrangement. In this case, in particular, the spatial light modulator can include a dynamically adjustable diffraction grating. As already explained in conjunction with the first aspect of the invention, a so-called line modulator can be used here. The line modulator can: change the state of the individual pixels at a frequency of at least 300 MHz, so that extremely high scanning speeds and thus writing speeds can be achieved.

[0040] The deflection unit can preferably have at least one acousto-optic modulator, wherein the acousto-optic modulator can be arranged upstream of the deflection unit. An acousto-optic modulator is an optical device that influences the frequency, propagation direction and / or intensity of the incident light. For this purpose, a grating is generated in a transparent solid with the aid of sound waves, at which the light beam is diffracted. This can be used in the case of a design variant referred to as an acousto-optic deflector to produce a beam deflection, wherein the deflection angle depends on the relative wavelengths of the light and sound waves in the transparent solid. In this case, the deflection angle can be adjusted by changing the frequency of the sound waves.

[0041] According to another preferred configuration scheme, the spatial light modulator has a two-dimensional pixel arrangement. In this context, the spatial light modulator can be configured as a reflective liquid crystal microdisplay, for example. The frame rate of such an LCoS device is greater than or equal to 60 Hz, which means that the entire pixel grid can change the pixel state more than 60 times per second. Therefore, in the case of building a component layer by layer, if the time required for the layer change is not taken into account, at least 60 layers of volume elements can be generated in the material per second.

[0042] For scanning a two-dimensional pixel grid with a plurality of beams, it is preferably provided that the deflection unit is designed as a two-axis deflection unit and preferably comprises a polygon scanner or a resonant scanner for deflecting the beam about a first axis and a galvanometer scanner for deflecting the beam about a second axis.

[0043] Another preferred embodiment provides that a polarization beam splitter is associated with the spatial light modulator, a plurality of beams are directed to the polarization beam splitter via the polarization beam splitter, and the polarization beam splitter deflects the beam reflected by the spatial light modulator to the optical imaging unit.

[0044] Here, another preferred embodiment proposes that: a polarization beam splitter is associated with a spatial light modulator, a plurality of beams are guided to the spatial light modulator through the polarization beam splitter, and the polarization beam splitter deflects the beam reflected by the spatial light modulator to the optical imaging unit

[0045] The beam is preferably polarized by arranging a retardation plate, in particular a λ / 2 or λ / 4 plate, between the polarization beam splitter and the spatial light modulator, thereby rotating the polarization of the beam so that a 90° change is obtained overall at the polarization beam splitter.

[0046] A preferred development of the described arrangement of the light modulator consists in that a mirror is provided and the spatial light modulator and the mirror are displaceable in such a way that the spatial light modulator or the mirror can be selectively brought into an operating position arranged in the beam path.

[0047] The irradiation device is preferably designed to build the component layer by layer in layers extending in an xy plane, wherein switching from one layer to the next includes changing the relative position of the optical imaging unit with respect to the component in a z direction extending perpendicularly to the xy plane.

[0048] Furthermore, it can be provided that the material is present in a material carrier, such as a bath, and that the irradiation of the material takes place from below through the material carrier which is at least partially transparent to the radiation.

[0049] In this case, the building platform is preferably positioned at a distance from the material carrier and the component is built on the building platform by solidifying the volume element located between the building platform and the material carrier.

[0050] The imaging unit can be designed as an f-theta lens or preferably consists of a microscope objective and relay optics in a 4f arrangement, wherein the deflection unit and the objective are placed in the focal plane of the corresponding lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The present invention will be explained in more detail below based on the embodiments schematically shown in the accompanying drawings. Figure 1 A schematic diagram showing a first embodiment of the device according to the invention, Figure 2 A schematic diagram showing a second embodiment of the device according to the invention, Figure 3 A modified configuration of the first and second embodiments is shown. Figure 4 A schematic diagram showing scanning of pixels of a spatial light modulator, Figure 5 Show according to Figure 4 The modified composition scheme of the view, and Figure 6 Show according to Figure 4 Another modified composition scheme of the view. DETAILED DESCRIPTION

[0052] exist Figure 1 In the figure, 1 denotes a carrier on which a component is to be constructed. The carrier 1 is coated with a photopolymerizable material 2, into which a laser beam is focused, wherein each laser beam is focused in turn onto a focal point within the photopolymerizable material, thereby curing a volume element of the material at the focal point by means of multiphoton absorption, respectively. For this purpose, a laser beam is emitted from a radiation source 3, guided through a pulse compressor 4 and uniaxially deflected by means of an acousto-optic modulator module 5 comprising two acousto-optic modulators 6 to perform a reciprocating movement. The zero-order beam is collected in a beam trap 7. The first-order beam is guided via a relay system 8 to a beam splitter 9, which splits the beam into a plurality of beams, which are guided via a scanning lens 17 to a polarization beam splitter 10. The polarization beam splitter is configured to allow a plurality of beams to pass in the direction of a spatial light modulator 11. Here, the beam passes through a delay plate 12, which relatively delays the polarization component by, for example, λ / 4. The polarization of the beam reflected by the spatial light modulator 11 is rotated again in the delay plate 12, so that the beam is deflected in the direction of the optical imaging unit 13 when it strikes the polarization beam splitter 10. Here, the beam reaches the optical imaging unit 13 via the tube lens 14. The optical imaging unit 13 includes an objective lens that introduces the laser beam into the material 2 in a focused manner in the writing area.

[0053] In accordance with Figure 1In the embodiment of the present invention, the spatial light modulator 11 is designed as a line modulator and includes a large number of pixels arranged in a row. Here, each pixel can be switched between an on and off state, for example, by an electronically controllable diffraction grating, so that the corresponding beam is reflected to the polarization beam splitter 10 only in the on state and then guided to the optical imaging unit 13.

[0054] The beam splitter 9 is configured to generate a plurality of beams distributed along the pixel rows, and the deflection unit 5 is configured to shift the plurality of beams together along the pixel rows, i.e., scan the pixel rows. Depending on whether the corresponding pixel is in an on state or an off state, the beam is reflected by the light modulator and introduced into the material 2 at the corresponding position.

[0055] After scanning a pixel row and producing corresponding solidified volume elements in the material 2, switching to the next row is done by arranging the carrier 1 on a cross-type stage, wherein the volume elements are arranged, for example, in a row extending in the y direction, wherein the cross-type stage can be displaced in the x direction relative to the optical imaging unit 13. In this way, volume elements can be produced in a plurality of rows. Figure 4 This is shown schematically in .

[0056] Figure 4 A row 23 of pixels 24 is shown, which extends, for example, in the x-direction. In the present example, a beam splitter generates two beams 25, which are arranged at a distance of six pixels from one another. The deflection device causes the group of two beams 25 to be moved according to arrows 26 and to scan the pixel row 23 in this way. The volume element should be cured at the location represented by the dark pixels. This is achieved in that the pixels are switched into the on state in the light modulator. After scanning the row 23, the carrier 1 is displaced by one unit in the y-direction, so that in addition to the previously cured volume element, further volume elements can also be cured, as is indicated by arrow 29. While scanning this pixel row, the other pixels are now switched into the on state, so that after a number of rows a volume element is created. Figure 4 The pattern shown in .

[0057] In order to build the component layer by layer, the volume elements are solidified layer by layer in the material 2. To build the first layer, the laser beam is focused successively to a focus in the material 2, which is arranged in the focal plane of the optical imaging unit 13. To switch to the next plane, the optical imaging unit 13 fixed to the carrier 15 adjusts the layer spacing in the z direction relative to the carrier 1. Alternatively, the carrier 1 can also be adjusted relative to the fixed optical imaging unit 13.

[0058] Furthermore, a control unit 16 is provided, which controls the deflection unit 5 , the beam splitter 8 , the light modulator 11 , the height adjuster 15 and the carrier 1 fastened to the crosshead.

[0059] In accordance with Figure 2 In the composition scheme, according to Figure 1 In contrast to the embodiment of the present invention, the spatial light modulator 11 has a two-dimensional pixel grid. Therefore, a deflection unit 19 is provided, which is capable of deflecting the plurality of beams generated by the beam splitter 9 about two perpendicular axes. For this purpose, the deflection unit 19 has a first scanner 20 and a second scanner 21, which are controlled so that the first scanner is connected to the beam splitter 9 according to the embodiment of the present invention. Figure 1 The scanning of each pixel row is performed as described in the embodiment of the present invention (in the x direction), and the second scanner deflects the beam transversely thereto (in the y direction) from one row to the next. Figure 1 Another difference of the configuration is that the deflection unit 19 is arranged after the beam splitter 9. In addition, the acousto-optic modulator 18 is arranged before the beam splitter 9, and the acousto-optic modulator is used to adjust the global power limit and limit the power at the turning point of the scanner to avoid damaging the modulator.

[0060] Due to the use of a spatial light modulator 11 with a two-dimensional pixel array, volume elements can be generated within the two-dimensional writing area of ​​the optical imaging unit 13. If the component to be produced is larger than the writing area of ​​the optical imaging unit 13 in the x and / or y direction, the substructures of the component are built up one after the other (so-called splicing). For this purpose, the carrier 1 is arranged on a cross table, which can be displaced relative to the optical imaging unit 13 in the x and / or y direction.

[0061] according to Figure 3 The composition and basis of Figure 2 The difference between the embodiments of is that if the function of the light modulator 11 can be omitted, a mirror 22 can be placed in the beam path instead of the spatial light modulator 11 .

[0062] The scanning of the two-dimensional pixel grid of the spatial modulator Figure 5 and Figure 6 Here, the individual pixels are again denoted by 24, and it can be seen that the pixels 24 are arranged in a plurality of rows, i.e., in a two-dimensional arrangement. Figure 5 In a variant embodiment, the beam splitter generates four beams 25 arranged in a square, wherein each beam is moved two-dimensionally on a pixel grid by means of a deflection device along a path indicated by 28. In this case, the beam is deflected in the direction of the double arrow 26 (x direction) for example by means of an acousto-optic deflector, and the beam is deflected in the direction of the double arrow 27 (y direction) for example by means of a galvanometer scanner. By switching between the on and off states, a Figure 5 , where the volume elements are solidified at locations represented by dark pixels (on state).

[0063] In accordance with Figure 6 In a variant embodiment of the invention, the beam splitter generates three beams 25 arranged in a linear manner, wherein the individual beams are moved two-dimensionally over a pixel grid by means of a deflection device along a path indicated by 28. In this case, the beams are deflected in the direction of the double arrow 26 (x direction) for example by means of a resonant scanner, and the beams are deflected in the direction of the double arrow 27 (y direction) for example by means of a galvanometer scanner.

Claims

1. A method for producing a three-dimensional component based on photolithography, wherein a beam emitted by an electromagnetic radiation source (3) is divided into a plurality of beams by means of a beam splitter (9), the plurality of beams are focused onto a focal point in a material (2) by means of an optical imaging unit (13), and the focal point is shifted by means of a deflection unit (5, 19) arranged upstream of the optical imaging unit (13) in the beam direction, thereby successively solidifying volume elements of the material (2) respectively located at the focal point by means of multiphoton absorption, characterized in that A spatial light modulator (11) is provided with a plurality of electronically controllable pixels, which are scanned by the plurality of beams and which are individually switched between at least one on state and one off state according to the geometry to be achieved of the component, so that the corresponding beam is guided to the imaging unit (13) only in the at least one on state.

2. The method according to claim 1, characterized in that The at least one on state includes at least a first on state and a second on state, wherein the pixels individually switch between the off state and the first and second on states, wherein the first and second on states generate different radiation intensities at the focus.

3. The method according to claim 1 or 2, characterized in that: The radiation intensity of each pixel of the spatial light modulator can be adjusted and the radiation intensity is adjusted according to the exposure duration of the pixel so that the volume element obtains the same radiation power.

4. The method according to claim 1 or 2, characterized in that: The radiation intensity of each pixel of the spatial light modulator can be adjusted and adjusted so that the volume elements obtain different radiation powers in order to produce volume elements with different spatial extensions, in particular different spatial extensions in the incidence direction.

5. The method according to any one of claims 1 to 4, characterized in that The pixels of the spatial light modulator (11) are arranged in at least one, for example, exactly one row extending along a straight line, and the beam is split along the straight line by means of the beam splitter (9) so that the beam strikes the pixel row at a distance of a plurality of pixels from one another.

6. The method according to claim 5, characterized in that The pixels of the spatial light modulator (11) are arranged in a plurality of parallel rows, and the plurality of beams are deflected around two preferably mutually perpendicular axes, wherein the beam deflection around the first axis is preferably carried out with the aid of a polygon scanner or a resonant scanner (21), and the beam deflection around the second axis is preferably carried out with the aid of a galvanometer scanner (20).

7. The method according to any one of claims 1 to 6, characterized in that The multiple beams are directed to the spatial light modulator (11) with a polarization beam splitter (10) inserted in between, the beams are reflected by the spatial light and incident on the polarization beam splitter (10) with changed polarization, and the polarization beam splitter directs the beams to the optical imaging unit (13).

8. The method according to any one of claims 1 to 7, characterized in that A mirror (22) is provided, and the spatial light modulator (11) and the mirror (22) are displaced so that the spatial light modulator (11) or the mirror (22) is selectively placed in an operating position arranged in the beam path.

9. The method according to any one of claims 1 to 8, characterized in that The component is constructed layer by layer in layers extending in an xy plane, wherein switching from one layer to the next includes changing the relative position of the optical imaging unit (13) with respect to the component in a z direction extending perpendicularly to the xy plane.

10. A device for producing a three-dimensional component based on photolithography, in particular for carrying out the method according to any one of claims 1 to 9, comprising a material carrier (1) for a curable material (2) and an irradiation device, which can be controlled to irradiate the curable material selectively by means of at least one beam, wherein the irradiation device comprises: A beam splitter (9) for splitting an input beam into a plurality of beams, a deflection unit (5, 19) arranged in the beam path upstream or downstream of the beam splitter (9), and an optical imaging unit (13) arranged downstream of the deflection unit (5, 19) and the beam splitter (9), so as to focus each beam successively onto a focal point in the material (2), thereby enabling volume elements of the material (2) respectively located at the focal points to be cured successively by means of multiphoton absorption, characterized in that a spatial light modulator (11) having a plurality of electronically controllable pixels is arranged between the imaging unit (13) on the one hand and the beam splitter (9) and the deflection unit (5, 19) on the other hand, the electronically controllable pixels being capable of being scanned by the plurality of beams and the electronically controllable pixels being capable of being individually switched between at least one on and one off state, so that the corresponding beam is guided to the imaging unit (13) only in the at least one on state.

11. The device according to claim 10, characterized in that The at least one on state comprises at least a first on state and a second on state, wherein the pixel is capable of switching individually between the off state and the first and second on states, wherein the first and second on states produce different radiation intensities at the focus.

12. The device according to claim 10 or 11, characterized in that The spatial light modulator (11) has a one-dimensional pixel arrangement.

13. The device according to claim 10, 11 or 12, characterized in that The spatial light modulator (11) comprises a dynamically adjustable diffraction grating.

14. The device according to any one of claims 10 to 13, characterized in that The deflection unit (5) has at least one acousto-optic modulator.

15. The device according to claim 10 or 11, characterized in that The spatial light modulator (11) has a two-dimensional pixel arrangement.

16. The device according to claim 15, characterized in that The spatial light modulator (11) is configured as a reflective liquid crystal microdisplay.

17. The device according to claim 15 or 16, characterized in that The deflection unit (19) is designed as a two-axis deflection unit and preferably comprises a polygon scanner or a resonant scanner (21) for deflecting the beam about a first axis and a galvanometer scanner (20) for deflecting the beam about a second axis.

18. The device according to any one of claims 10 to 17, characterized in that A polarization beam splitter (10) is associated with the spatial light modulator (11), the multiple beams are guided to the spatial light modulator (11) through the polarization beam splitter, and the polarization beam splitter deflects the beam reflected by the spatial light modulator (11) to the optical imaging unit (13).

19. The device according to claim 18, characterized in that A retardation plate (12), in particular a λ / 2 or λ / 4 plate, is arranged between the polarization beam splitter (10) and the spatial light modulator (11).

20. The device according to any one of claims 10 to 19, characterized in that A mirror (22) is provided, and the spatial light modulator (11) and the mirror (22) are displaceable such that the spatial light modulator (11) or the mirror (22) can be selectively placed in an operating position arranged in the beam path.

21. The device according to any one of claims 10 to 20, characterized in that The irradiation device is designed to construct the component layer by layer in layers extending in an xy plane, wherein switching from one layer to the next includes changing the relative position of the optical imaging unit (13) with respect to the component in a z direction extending perpendicularly to the xy plane.

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