METHOD FOR THE LITHOGRAPHY-BASED ADDITIVE MANUFACTURING OF A THREE-DIMENSIONAL COMPONENT

Abstract

In a method for the lithography-based generative production of a three-dimensional component, in which electromagnetic radiation emitted by an irradiation device is successively focused on focal points within a material, wherein in each case a volume element of the material located at the focal point is solidified by means of multiphoton absorption, wherein a substructure is each built up from the volume elements in a writing area of the irradiation device, the build-up of the component comprises the following steps: a) a plurality of substructures are arranged next to one another, then b) substructures are arranged one above the other so that upper substructures bridge the interface(s) between lower substructures arranged next to one another.

Claims

1. A method for the lithography-based generative production of a three-dimensional component, in which electromagnetic radiation emitted by an irradiation device is successively focused on focal points within a material, wherein in each case a volume element of the material located at the focal point is solidified by means of multiphoton absorption, wherein a substructure is built up from the volume elements in a writing area of the irradiation device and a plurality of substructures is built up by displacing the writing area to different positions, characterized in that the build-up of the three-dimensional component comprises the following steps: a) the plurality of substructures are arranged next to one another, then b) substructures are arranged one above the other so that upper substructures bridge the interface(s) between lower substructures arranged next to one another.

2. The method according to claim 1, characterized in that the three-dimensional component comprises several superimposed layers, which are each formed from the plurality of substructures arranged next to one another, wherein the three-dimensional component is built up in layers, wherein the substructures of an upper layer bridge the interface(s) between adjacent substructures of the layer arranged immediately below.

3. The method according to claim 2, characterized in that the interface(s) between layers lying one on top of the other layer is flat throughout.

4. The method according to claim 2, characterized in that the interface(s) between substructures lying one above the other is stepped.

5. The method according to claim 1, characterized in that the writing area of the irradiation device is displaced by changing a relative position of the irradiation device relative to the material transversely to an entry direction of the irradiation device in order to build up, after the substructure has been built up, a next adjacent substructure.

6. The method according to claim 1, characterized in that two lower substructures adjoining one another at an interface are each overlapped by at least 10% by the upper substructure that bridges said interface.

7. The method according to claim 1, characterized in that the thickness of the substructures and/or of the layers is less than 100 μm.

8. The method according to claim 1, characterized in that the material is present on a material carrier and the material is irradiated from below through the material carrier which is at least partially transparent to the electromagnetic radiation.

9. The method according to claim 8, characterized in that a building platform is positioned at a distance from the material carrier and the three-dimensional component is built up on the building platform by solidifying material located between the building platform and the material carrier.

10. The method according to claim 1, characterized in that a volume of the focal point is varied at least once during construction of the three-dimensional component, so that the three-dimensional component is built up from solidified volume elements of different volumes.

11. The method according to claim 10, characterized in that a change in the focal point volume takes place in at least two spatial directions perpendicular to one another.

12. The method according to claim 1, characterized in that the electromagnetic radiation is deflected by means of a deflection unit in order to adjust the focal point within the writing area in a plane that is essentially perpendicular to an entry direction.

13. A three-dimensional component produced by a method according to claim 1.

Description

[0035] The invention is explained in more detail below with reference to exemplary embodiments shown schematically in the drawing. Therein,

[0036] FIG. 1 shows a schematic representation of a conventional method for building a three-dimensional component,

[0037] FIG. 2 shows a method according to the invention,

[0038] FIG. 3 shows a modified embodiment of the method according to FIG. 2,

[0039] FIG. 4 shows a further modified embodiment of the method according to FIG. 2,

[0040] FIG. 5 show a further modified embodiment of the method according to FIG. 2,

[0041] FIG. 6 shows another modified embodiment of the method according to FIG. 2, and

[0042] FIGS. 7 and 8 show further modified embodiments.

[0043] In FIG. 1, an optical unit 1 of an irradiation device is shown schematically in cross section, which has an entry direction 2. The entry direction 2 indicates the direction in which the electromagnetic radiation is emitted from the irradiation device onto the component 3 to be formed in the basic setting. The irradiation device has a writing area with an extension 4 which corresponds to the width within which the emitted radiation can be focused on focal points 5 within the material which is to be solidified by the radiation. In order to be able to focus one after the other on different focal points within the writing area, the irradiation device comprises a unit not shown in detail, such as a deflection unit. If said unit is designed to change the direction of irradiation, the term “entry direction” is to be understood as the main entry direction of the irradiation device in the basic position.

[0044] Since the extension 4 of the writing area is not sufficient to produce the entire component, the component is built up from a plurality of substructures 6 arranged next to one another. The procedure here can be such that the substructure 6 is built up from a plurality of layers 9 in the height direction. First, a first substructure 6 is formed, which lies within the writing area of the irradiation device. Thereafter, the writing area is displaced laterally by moving the irradiation device relative to the component 3 or by moving the component 3 relative to the irradiation device in order to build up a second substructure 6 next to the first substructure 6. This is repeated until the finished component 3 has been built up from all the substructures. A component constructed in this way has mechanical weak points at the interfaces 7 between substructures 6 arranged next to one another.

[0045] Furthermore, when a certain height of a substructure 6, measured in the entry direction, is exceeded, shadowing occurs. This means that an already built-up substructure 6 can shadow the beam coming from the optical unit 1 and directed to a focal point within the substructure adjoining it on the left, as is shown schematically with the aid of line 8. In the area delimited by line 8, there are therefore structuring errors that must be avoided.

[0046] In FIG. 2 it can be seen that the component 3 is built up again from a plurality of substructures 6 according to the method according to the invention, the substructures 6 now not only being arranged next to one another but also one above the other. In the embodiment according to FIG. 2, the substructures 6 are for this purpose arranged in layers 10 arranged one above the other, so that the interface 11 between layers 10 lying one above the other is continuously flat. Because the component 3 is composed not only in the lateral direction but also in the height direction from a plurality of substructures 6, each individual substructure 6 can be designed with a reduced height with a view to avoiding shadowing. This also opens up the possibility of laterally offsetting the substructures 6 of the individual layers 10 with respect to one another, so that upper substructures 6 bridge the interfaces 7 between substructures 6 arranged next to one another and directly below. In the embodiment according to FIG. 2, the lateral offset is half the width of the individual substructures 6, so that two lower substructures 6 adjoining one another at an interface 7 are each 50% overlapped by the upper substructure 6 bridging this interface 7.

[0047] In the modified embodiment according to FIG. 3, the offset is only 10%.

[0048] While the interfaces 7 between substructures 6 arranged next to one another run parallel to the entry direction 2, FIG. 4 shows various alternative possibilities, namely curved and stepped interfaces 7 as well as interfaces 7 running obliquely to the entry direction 2. In this way, shadowing can also be prevented.

[0049] In FIG. 5, a further modified embodiment is shown, in which the substructures 6 lying one above the other are not arranged in layers, but rather according to a stepped arrangement. The substructures 6 each have a surface on their underside and on their upper side which has a step at the point at which an interface 7 is provided between substructures lying below or above it. Due to such a stepped configuration, the protruding portion b of the height a of a substructure 6 relevant with regard to shadowing is lower than in an embodiment according to FIG. 2, so that shadowing can be avoided even more effectively or the height of the substructures can be increased without increasing the risk of shadowing.

[0050] In FIG. 6 an alternative arrangement of the substructures 6 is shown, the interfaces 11 between superimposed substructures 6 or between the layers 10 now not extending at right angles to the entry direction 2, but obliquely the entry direction 2 at an angle of max. 45°, preferably max. 30°.

[0051] FIG. 7 shows a further possibility for the arrangement of the substructures 6 according to the invention. The substructures 6 here have a hexagonal cross-section, so that a honeycomb arrangement of substructures arranged next to one another and one above the other results.

[0052] In the embodiment according to FIG. 8, the substructures 6 are in the form of crosses.

[0053] It should be noted that the substructures 6 as shown in FIGS. 1 to 8 are only represented by border lines which indicate the spatial area in which the solidification of the volume elements takes place within the respective substructure without a specific structuring being represented. It goes without saying that within the framework of the production of a component of the respectively desired geometry, not all volume elements have to be solidified within a substructure, but that volume areas can remain free within the substructures.