DE102019123100A1 - Process for the generative production of SiC-containing structures - Google Patents

Abstract

The present invention relates to an, in particular generative, method for producing SiC-containing structures which are obtained by a repeated and / or continuous input of energy into a precursor material by at least one radiation source.

Description

The present invention relates to the technical field of the production of SiC-containing materials, in particular by means of additive manufacturing processes.

In particular, the present invention relates to a method for producing SiC-containing structures which are obtained by a repeated and / or continuous input of energy into a precursor material by at least one radiation source.

The present invention further relates to a use of a radiation source, in particular a laser, preferably a laser array, for the production of SiC-containing structures.

Finally, the present invention relates to SiC-containing structures obtainable by the method according to the invention.

Generative manufacturing processes, also known as additive manufacturing or additive manufacturing (AM), denote processes for the rapid manufacture of models, samples, tools and products from shapeless materials, such as liquids, gels, pastes or powders.

Here, generative manufacturing processes are used both for the production of spatial structures and objects from inorganic materials, in particular metals and ceramics, as well as from organic materials. High-energy processes, such as selective laser melting (SLM), electron beam melting or build-up welding, are preferably used especially for the production of structures from inorganic materials, since the starting materials or precursors used only react or melt when higher energy input is used.

In general, generative manufacturing processes enable time-efficient and flexible production of, among other things, highly complex spatial structures that would be difficult to access using subtractive manufacturing processes. However, the economic viability of these, in particular high-energy, processes is not yet fully developed for industrial applications, with the production of larger components and structures or the production of larger series in particular still causing problems and sometimes taking a relatively long time. This applies in particular to the processing of inorganic, in particular ceramic, materials, whereas developments in the field of additive manufacturing of plastic-based structures are already much more advanced, especially with regard to industrial suitability, for example in the form of economically feasible series production.

This is due, among other things, to the fact that the production of structures or components from inorganic materials poses a number of special challenges to both the educt and the product materials: the educts have to react in a specially prescribed manner when exposed to energy , whereby in particular disruptive side reactions must be excluded. In addition, no segregation or phase separation in the starting material and no decomposition of the products produced may occur, for example, in the course of the input of energy. Therefore, in the context of conventional 3D printing processes, such as fused filament fabrication, for the production of three-dimensional structures from inorganic, in particular ceramic, materials, a green body is often first created in the desired shape and this is then converted into the desired material through a sintering step. However, this procedure is very energy-consuming and tedious.

Silicon carbide, also known as carborundum, is an extremely interesting and versatile material for mechanically heavily loaded structures or components as well as for semiconductor applications. Silicon carbide, with the chemical formula SiC, is extremely hard and has a high sublimation point. It is therefore often used, for example, as an abrasive or as an insulator in high-temperature reactors.

In addition, silicon carbide forms alloys or alloy-like compounds with a large number of elements and compounds, which have a large number of advantageous material properties, such as high hardness, high resistance, low weight and low sensitivity to oxidation, even at high temperatures.

SiC-containing materials are usually accessible by sintering processes from educts or educt mixtures which contain SiC particles. However, relatively porous bodies are obtained, which are accordingly only suitable for a limited number of fields of application.

In addition, the properties of the porous SiC material produced using conventional sintering processes do not correspond to those of compact crystalline silicon carbide, so that the generally advantageous properties of silicon carbide cannot be fully exploited.

In addition, it is noteworthy that silicon carbide does not melt, but sublimes, at high temperatures - depending on the respective crystal type - in the range between 2,300 and 2,700 ° C. This means that silicon carbide changes directly from the solid to the gaseous state of aggregation. Silicon carbide is therefore not suitable or only suitable to a very limited extent as a starting material in high-energy processes for the efficient production of corresponding inorganically based structures or bodies.

Due to the versatile applicability of silicon carbide and the large number of positive application properties, approaches that overcome this disadvantage and related attempts to produce SiC-containing structures by means of additive manufacturing processes are of great interest.

An efficient possibility of producing silicon carbide-containing materials or bodies consists in the use of suitable precursor compounds or materials, which react under the action of energy to form silicon carbide or SiC-containing materials.

So describes the DE 10 2015 100 062 A1 a process for the production of SiC-containing materials, in particular SiC crystals or fibers, which are obtained by deposition from the gas phase. For this purpose, a precursor granulate is used as the starting material, which is obtained by a sol-gel process and then subjected to a thermal treatment at over 1,000 ° C.

In addition, additive manufacturing processes for the direct manufacture of SiC-containing objects from suitable precursor materials are also known, for example from DE 10 2015 105 085 A1 , of the DE 10 2017 110 362 A1 , of the DE 10 2017 110 361 A1 or also the DE 10 2019 121 062.3 .

The DE 10 2015 105 085 A1 describes, for example, a method for producing bodies from SiC crystals, the silicon carbide being obtained in particular by laser irradiation of precursor materials formed from suitable carbon and silicon sources. Under the action of the laser beam, the precursor materials decompose selectively and silicon carbide is formed without sublimation processes occurring.

However, the reproducible representation of the precursor material is according to FIG DE 10 2015 105 085 A1 , which is obtained via a sol-gel process, tedious and expensive. In this case, the aging of the compounds used from a sol to a gel is initially very time-consuming. In addition, the product obtained from the sol-gel process by simple drying has varying compositions, since, inter alia, solvents and acids that are necessarily used partly remain in the dried product. These residues tend to side reactions, especially at higher drying temperatures and in the course of the thermal aftertreatment. A reductive thermal treatment of the precursor material is therefore preferably carried out at high temperatures in order to bring about the conversion into a stable and reproducible precursor material form.

In contrast, describes the DE 10 2019 121 062.3 an optimized process that makes it possible to reproducibly obtain a defined, uniformly composed SiC precursor granulate by first homogenizing or dissolving the individual components or starting materials of the granulate composition in a preferably colloidal solution or dispersion. This is followed by the rapid removal of the solvent or dispersant, since it has been shown that aging of the colloidal solution to a gel, as in the DE 10 2015 105 085 A1 is not necessary.

Likewise, in the context of the method according to DE 10 2019 121 062.3 the costly thermal treatment at temperatures of over 1,000 ° C is dispensed with, which results in significant time and energy savings. This also implies, as it were, a significant reduction in the costs for the production of an SiC precursor granulate.

The DE 10 2017 110 362 A1 or. WO 2018/206645 A1 relates to the production of SiC-containing objects, in particular from silicon carbide alloys, starting from powdery precursor materials by means of what is known as selective synthetic crystallization.

The selective synthetic crystallization relates in detail to high-energy processes for the production of silicon carbide and silicon carbide alloys, preferably by means of additive manufacturing. The selective synthetic crystallization includes processes which are connected to laser deposition welding, as described, for example, in DE 10 2018 128 434.9 , the selective laser melting, as described for example in the DE 10 2017 110 362 A1 or. WO 2018/206645 A1 , or the inkjet printing process, such as from the DE 10 2017 110 361 A1 or. WO 2018/206643 A1 are known, based on and in which an SiC-containing object is successively generated from an SiC precursor material through a targeted energy input, in particular a location-selective energy input.

What all these methods have in common is that the energy input into the material provided, in particular the SiC precursor material, is carried out by a high-energy radiation source. _{Lasers such as CO 2} lasers, Nd: YAG lasers or fiber lasers are often used for this purpose. These radiation sources achieve the necessary power to induce a sufficiently high energy input into the precursor material so that the formation of silicon carbide can take place.

However, the laser variants mentioned are only radiation sources that can only be used individually. This is due to the fact that CO ₂ lasers, Nd: YAG lasers or fiber lasers cannot or only poorly be arranged in groups, since, for example, efficient heat dissipation during ongoing, combined and concerted operation of the lasers is hardly possible.

This means that generative manufacturing processes such as Selective Synthetic Crystallization, Laser Deposition Welding or Selective Laser Melting are severely limited in terms of the speed at which a spatial structure can be built up, because at a certain point in time only a certain, locally strictly limited structure can be created Area to be processed with the laser.

As a result, the production of large and also structurally complex components and structures, especially in series, is still disproportionately time-consuming. As a consequence, this fact significantly reduces the industrial applicability of generative manufacturing processes, since long manufacturing times for industrial productions are ultimately not very acceptable because they are uneconomical and cost-inefficient.

The prior art therefore still lacks efficient generative manufacturing processes, in particular for spatial structures that contain and / or consist of silicon carbide.

The present invention is therefore based on the object of eliminating the aforementioned disadvantages associated with the prior art, or at least reducing them.

In particular, one object of the present invention is to provide a method for producing SiC-containing structures which represents an improvement and increase in efficiency compared to the previous methods known from the prior art.

A related further object of the present invention is to provide a manufacturing method for SiC-containing structures that allows shorter manufacturing times and can also be classified as energy-saving compared to known methods of the prior art and is therefore suitable for use in industrial productions , especially series productions.

The present invention according to a first aspect of the present invention is therefore a method for producing SiC-containing structures according to claim 1; further advantageous refinements of this aspect of the invention are the subject matter of the relevant subclaims.

A further subject matter of the present invention according to a second aspect of the present invention is a use of a radiation source, in particular a laser, for the production of SiC-containing structures according to claim 17.

Finally, according to a third aspect of the present invention, the present invention again further provides an SiC-containing structure according to claim 18.

It goes without saying that the special configurations mentioned below, in particular special embodiments or the like, which are only described in connection with one aspect of the invention, also apply accordingly with regard to the other aspects of the invention, without this needing to be explicitly mentioned.

Furthermore, with all of the relative or percentage, in particular weight-related, quantitative data mentioned below, it should be noted that these are to be selected by the person skilled in the art within the scope of the present invention in such a way that the sum of the ingredients, additives or auxiliaries or the like is always 100 percent or 100 % By weight result. However, this goes without saying for the expert.

In addition, it applies that all of the parameter information or the like mentioned below can in principle be determined or determined using standardized or explicitly stated determination methods or with determination methods that are known per se to the person skilled in the art.

Having said that, the subject matter of the present invention is explained in more detail below.

The present invention - according to a first aspect of the present invention - is a process for the production of SiC-containing structures, whereby a precursor material, containing at least one silicon source and at least one carbon source, is converted to a SiC-containing material.

Because, as the applicant has surprisingly found out, the method according to the invention allows a significant increase in the method efficiency and, in particular, the production speed with which a structure containing SiC can be obtained.

With the aid of the method according to the invention, particularly high production speeds can be achieved because, in contrast to the radiation sources usually used in the context of generative manufacturing processes, in particular lasers, radiation sources are used in the context of the present invention that can be grouped or combined so that a concerted time-specific as well as Site-selective irradiation and conversion of a precursor material, preferably provided in the form of a material bed, to SiC-containing structures is possible.

In the context of the present invention, a radiation source is understood to mean, in particular, an irradiation device which emits electromagnetic radiation, in particular laser radiation. The radiation source or irradiation device can have, in addition to the means for generating the radiation, in particular the actual radiators, preferably lasers, further means and devices, such as deflection means for deflecting the electromagnetic radiation, in particular mirror arrangements, optical waveguides, lenses, etc., which have a focusing and allow local limitation of the effective range of the electromagnetic radiation.

The radiation source used preferably has a plurality or a plurality of individual radiators, which accordingly can individually irradiate a predefined area of a material bed over a predetermined period of time in coordination with one another, so that the entirety of all individual radiators in comparison to a single radiator in a significantly shorter time can cover all areas of the material bed to be irradiated.

In this way, within the scope of the additive manufacturing of the SiC-containing structure, a significant time saving can already be achieved for each SiC precursor material layer or layer, since the areas of a layer or layer in which the precursor material is to be converted into silicon carbide are no longer individually must be scanned by a laser linearly over time, but can be irradiated in a location-selective manner over a specific period of time. In relation to a spatial structure, this time saving is added up successively per layer, so that finally a spatial structure containing SiC can be obtained in a much shorter time than before.

In addition, it is a further essential advantage of the present invention that the individual emitters, in particular laser diodes, which can be used for the production of SiC-containing structures, individually have much lower powers and are, as it were, arranged and grouped overall in such a way that in the course of the irradiation of the SiC precursor material, energy inputs and temperatures are generated in it, as they are prerequisites for the formation of silicon carbide.

In addition, the radiation sources used according to the invention are characterized in that they have a small focus, so that the energy input is locally limited, that is to say particularly selective. In this way, a particularly high printing precision can be achieved and, in particular, filigree spatial structures are still well resolved. The method according to the invention thus allows improved access even to small-scale SiC-containing molded structures, and this within a shorter time than could be achieved with comparable methods of the prior art.

Furthermore, the method according to the invention is characterized by a high degree of flexibility with regard to usable precursor materials. In particular, the manufacturing process for SiC-containing structures according to the present invention can be carried out both with solid and liquid precursor material mixtures, i.e. both SiC precursor powder and SiC precursor dispersions can be used without problems and efficiently converted to SiC-containing structures and built up. In addition to the particular flexibility, this aspect also impressively illustrates the pronounced user-friendliness of the method according to the invention.

With the aid of the method according to the invention, both three-dimensional objects and semiconductor structures made of SiC-containing materials can be obtained, as will be explained below.

A further advantage of the method according to the invention for producing SiC-containing structures is the possibility of performing the method on devices, in particular print bed-based generative manufacturing devices, which are usually provided for processing plastics into spatial structures. This becomes possible because, in the context of the method according to the invention, it is also possible, in particular, to use such low-energy radiation sources as previously only in the area in the additive manufacturing of plastics.

This is because, surprisingly, the applicant found that the production of SiC-containing structures according to the invention requires less energy than previously assumed, i.e. the precursor materials used can be reliably decomposed according to the invention despite an inherently lower level of energy irradiation. Here, the effective decomposition of the precursor material is decisive for the production of SiC-containing materials, since the SiC formation ultimately takes place through recombination of the precursor material fragments produced in and out of the gas phase. So far, these processes have only been triggered by means of high-energy radiation sources. With the method according to the invention for the production of SiC-containing structures, this limitation is now overcome.

It is therefore a particular advantage of the method according to the invention that the temperature in the precursor material can be increased by a repeated and / or continuous input of energy, in particular by irradiating the precursor material, preferably with a laser array of in particular low-energy individual radiators such as diode lasers, for example, so that decomposition can occur of the precursor material as well as the recombination of the generated precursor material fragments to form crystalline SiC-containing material can be achieved reliably and efficiently despite an intrinsically low energy input.

This also results in a particular simplification of the process, since diode lasers, such as VCSEL diode lasers, are characterized, among other things, by their compact design, long service life and low power degradation.

In this context, it was also surprisingly observed that the crystallinity and compactness of the SiC-containing material can be increased in a particular way if the temperature at the irradiated areas also exceeds the decomposition of the precursor material, ie during the recombination and deposition of the SiC-containing material Material, remains increased, in particular by direct irradiation with low-energy radiation or by irradiating directly adjacent regions.

In general, in the context of the present invention, silicon carbide or an SiC-containing compound, in particular an SiC-containing material, is understood to mean a binary, ternary or quaternary inorganic compound whose empirical formula contains silicon and carbon. In particular, an SiC-containing compound does not contain any molecularly bound carbon, such as in the case of carbon monoxide or carbon dioxide, for example, but rather the carbon in the SiC-containing compound is in the form of a solid structure.

In addition, in the context of the present connection, an SiC-containing structure is understood to mean a two- or three-dimensional structure. The two-dimensional structures are characterized by the fact that they almost exclusively extend in only two spatial directions, i.e. in one plane, while the extent in the third spatial direction is negligible compared to the extent in the other two spatial directions. Such two-dimensional structures are particularly suitable for use in semiconductor technology and are often formed by doped silicon carbides.

Also of interest, however, are finely structured three-dimensional semiconductor components made from solid silicon carbide, which are also accessible with the method according to the invention. The three-dimensional structures are, in particular, three-dimensional objects or bodies which generally consist of SiC-containing material, in particular high-performance ceramics or silicon carbide alloys.

Furthermore, in the context of the present invention, a precursor material is understood to mean a chemical compound or a mixture of chemical compounds which can react to one or more target compounds by chemical reaction and / or under the action of energy.

Within the scope of the present invention, a silicon source and carbon source contained in a precursor material are understood to mean one or more chemical compounds that contain carbon and silicon, it being possible for the individual compounds to contain carbon and / or silicon. Compounds which contain carbon and silicon are preferably suitable as corresponding silicon or carbon sources in precursor materials according to the invention for the target compound containing SiC to be produced.

As far as the aspect of energy input is concerned, this can generally be done in a number of ways. In the context of the present invention, however, it has preferably proven useful if the energy input takes place by means of electromagnetic radiation, in particular laser radiation.

Furthermore, it has proven to be advantageous if the energy input is limited in terms of location and / or time, in particular in terms of location and time limited, takes place. Particularly good results can be obtained within the scope of the present invention if the energy input takes place selectively in a time-specific manner.

In the context of the present invention, a location-selective, time-specific energy input is understood to mean that energy is input into the precursor material at a specifically selected location, which is in particular spatially narrowly limited, at a specific, previously determined point in time over a specific, predetermined period of time . This means in particular that, for example, in two different, in particular spatially narrowly limited, locations, energy can be entered individually at a given time over a respectively predetermined duration. In the context of preferred embodiments of the present invention, the energy input into the material can take place parallel to one another by a plurality or plurality of radiation sources, so that a plurality or plurality of, in particular spatially narrowly limited, locations, for example in the form of pixels, are individually variable can be irradiated.

Furthermore, it has proven to be advantageous in the context of the present invention if the energy input has an effective range of less than 750 μm, in particular less than 500 μm, preferably less than 300 μm, preferably less than 150 μm.

In the context of the present invention, the effective area which the energy input has is understood to mean the smallest area of the simultaneous action of radiation in the irradiated material. In the case of laser beams, this corresponds in particular to the cross-section or diameter of the laser beam when it strikes the material or to the smallest extent of the radiation on the material point that occurs when masks are used. The larger the area which is at least covered by the energy input, the lower the resolution of the energy input.

In turn, it is further preferred in the context of the present invention if the energy input has an effective range of 0.1 to 750 μm, in particular 0.2 to 500 μm, preferably 0.5 to 300 μm, preferably 1 to 150 μm.

In addition, it has proven to be advantageous within the scope of the present invention if the energy input causes a temperature increase, in particular a locally and / or temporally limited temperature increase, preferably a locally and temporally limited temperature increase. Very particularly good results are observed in the context of the present invention when the input of energy causes a temperature increase that is limited in a location-selective manner and in a time-specific manner.

According to a further preferred embodiment of the present invention, it can be provided that the energy input causes a temperature increase to temperatures in the range of more than 1,000 ° C, in particular more than 1,400 ° C, preferably more than 1,600 ° C.

In the context of this preferred embodiment of the present invention, it can also be provided that the energy input causes a temperature increase to temperatures in the range from 1,300 to 2,200 ° C, in particular 1,700 to 2,000 ° C, preferably 1,700 to 1,900 ° C.

As far as the radiation source used according to the invention is concerned, it can have a structure known per se to the person skilled in the art. Thus, within the scope of the present invention, according to a particular embodiment of the invention, it can be provided that the radiation source is formed by a single radiation source, in particular a single-beam laser. In this case, it has proven to be particularly advantageous if the energy input into the precursor material takes place repeatedly, in particular in a pulsed manner. Accordingly, according to this embodiment of the method according to the invention, the single-beam laser can preferably be designed as a pulse laser, in particular as a short pulse laser, preferably as an ultra-short pulse laser.

In the context of the present invention, however, it has preferably proven useful if the radiation source has a plurality of, in particular more than 20, preferably more than 50, preferably more than 100, individual radiators, in particular individual emitters, in particular is formed from them.

It has also proven to be advantageous within the scope of the present invention if the radiation source is a laser, in particular a diode laser, preferably a grouping of several diode lasers, preferably a laser array, more preferably a VCSEL laser array.

In this context, a grouping of several diode lasers in the context of the present invention is understood to mean an arrangement of diode lasers in which a plurality or multiplicity of individual diode lasers or laser diodes are combined or connected electrically and / or optically, in particular electrically and optically . Such groupings are often also referred to as bars or laser bars or laser bars and are provided on a strip-shaped chip having the diode laser. The clustered diode lasers are usually operated electrically in parallel and mounted on a heat sink.

Accordingly, within the scope of the present invention, it can preferably be provided that the radiation source is designed as a laser bar or laser bar.

In the context of an alternative, but likewise preferred embodiment of the present invention, it can likewise be provided that the radiation source has a combination of at least one individual radiator with at least one optical waveguide, in particular glass fiber cable, and / or at least one lens. In the context of this embodiment of the present invention, it has proven particularly useful if the radiation source has a combination of a plurality of individual radiators with a plurality, in particular a bundle, of optical waveguides, in particular glass fiber cables, and / or a plurality of lenses. It is further preferred here if the radiation source has both optical waveguides, in particular glass fiber cables, and at least one lens.

According to this alternative embodiment of the present invention, it is possible that at least part of the radiation source, namely the means for generating the electromagnetic radiation, in particular the radiators, are arranged separately, i.e. locally independent of the print bed or area, and in particular also stationary. The combination of the means for generating the electromagnetic radiation, ie in particular the single beam laser or also the grouping of individual emitters or in particular individual emitters, preferably diode lasers, with the at least one optical waveguide, in particular glass fiber cable, or the plurality of optical waveguides, in particular glass fiber cables, then makes it possible for laser beams to be guided to a movable exposure means that preferably has the at least one lens, or in particular a plurality of lenses. The lens or lenses in turn allow the deflection or focusing of laser beams, so that, as a result, also according to this embodiment of the present invention, the energy input is limited locally and / or temporally, in particular limited spatially and temporally, preferably limited in a location-selective manner in a time-specific manner.

An advantage of this alternative embodiment of the present invention is that it is possible to focus the laser beams, in particular pixel-by-pixel, without the radiation source, in particular the grouping of the individual emitters or, in particular, individual emitters, preferably diode lasers, having to be arranged in the form of these pixels , ie the distance between the individual radiators can be greater than the area of a pixel. In addition, an optimized weight distribution of the radiation source can in particular also be achieved through this arrangement.

Furthermore, it is preferred within the scope of the present invention if the radiation source, in particular the individual radiators, have powers of less than 7 W, in particular less than 5 W, preferably less than 4 W, preferably less than 3 W. This means that in the context of the present invention, preferably low-energy radiation sources are used, which are also energy-saving in comparison to the high-energy radiation sources conventionally used in comparable manufacturing processes.

Furthermore, it is preferred in the context of the present invention if the radiation source, in particular the individual radiators, emit radiation with an effective range of less than 500 μm, in particular less than 300 μm, preferably less than 200 μm, preferably less than 150 μm . It has also proven to be advantageous if the radiation source, in particular the individual radiators, radiation with an effective range of 0.1 to 500 μm, in particular 0.2 to 300 μm, preferably 0.3 to 200 μm, preferably 0.5 to 150 µm, emit.

It has therefore proven to be particularly advantageous for the method according to the invention to use radiation sources or, in particular, individual emitters which emit radiation within a very narrow focus. Thus, the present invention ideally combines the preferred use of low-energy and, at the same time, particularly sharply focusing radiation sources, in particular in the form of groupings of corresponding individual emitters, such as in laser arrays, for example. Thus, within the scope of the present invention, a particularly high resolution can be achieved in the manufacture of a structure containing SiC.

1. (a) ein Precursormaterial, enthaltend mindestens eine Silicium-Quelle und mindestens eine Kohlenstoff-Quelle, in Form einer Lage, insbesondere einer Schicht, bereitgestellt wird, und
2. (b) durch einen wiederholten und/oder andauernden Energieeintrag durch mindestens eine Strahlungsquelle zumindest bereichsweise zu einem SiC-haltigen Material umgesetzt wird,

wobei die Verfahrensschritte (a) und (b) so oft wiederholt werden, dass eine SiC-haltige Struktur erhalten wird.In the context of the present invention, according to a further, particularly preferred embodiment of the present invention, it has proven useful if for the production of SiC-containing structures

1. (a) a precursor material containing at least one silicon source and at least one carbon source is provided in the form of a layer, in particular a layer, and
2. (b) is converted into a SiC-containing material at least in some areas through a repeated and / or continuous input of energy by at least one radiation source,

wherein process steps (a) and (b) are repeated so often that an SiC-containing structure is obtained.

In the context of the present invention, under a layer or in particular a layer of the precursor material containing at least one silicon source and at least one carbon source, a distribution of this material in a certain thickness on a plane, in particular a cutting plane through the structure to be produced , Roger that. The plane can be completely covered with the precursor material. Likewise, it can alternatively also be provided that the plane is not completely covered with the material, but rather only certain areas of the plane.

In each of these two cases, the application of the precursor material as a layer, in particular a layer, in the form of the described planes, in particular sectional planes through the structure to be produced, also ultimately defines the structure in such a way that the overall result is a layered structure of the SiC-containing structure.

Furthermore, an at least regional conversion of the precursor material into a SiC-containing material is understood within the scope of the invention to mean that the energy input required for this is limited in terms of location and / or time, in particular limited in terms of location and time, preferably time-specifically limited in terms of location, through which at least one radiation source occurs can. It is thus possible that not all areas of the plane, in particular the cutting plane through the structure to be produced, in which the precursor material is provided as a layer, in particular a layer, are irradiated in the same way. Instead, a spatially and time-resolved energy input through the at least one radiation source is possible, so that only special, predetermined areas of the plane, in particular the cutting plane through the structure to be produced, in which the precursor material is provided as a layer, in particular a layer, are converted to the silicon carbide-containing structure . In this case, particularly in the event that not all areas of the plane are completely covered with the precursor material, it can be preferred to irradiate only those areas in which the precursor material is present as a layer, in particular a layer.

In addition, it can also be provided that different precursor materials are used in different areas of the plane. This allows in particular the production of conductor tracks or generally of semiconductor electronics from and in SiC-containing materials, the provision of the different precursor materials in the plane preferably taking place by means of a print application, in particular by means of an inkjet method. As a result of this possibility of being able to use several different precursor materials in one print, the method according to the invention can in particular also be designed as a multi-material printing method, preferably in the form of an inkjet method. In this context, a layer or layer of the precursor material can preferably also be provided in such a way that several different precursor materials are provided simultaneously in the form of a layer or layer, in particular by means of printing processes, preferably by means of inkjet processes.

With regard to the nature and composition of the precursor material in general, this can vary within wide ranges and depending on the intended nature of the desired silicon carbide.

In the context of the present invention, it has proven to be advantageous if the precursor material is selected from the group of solid-in-solid precursor material mixtures, solid-in-liquid precursor material mixtures, and liquid-in-liquid precursor material mixtures. In particular, it can be provided in this context that the precursor material is selected from the group of precursor powders, precursor dispersions, preferably from precursor granules or precursor sols.

Solid-in-solid precursor material mixtures, in particular a precursor powder, preferably a precursor granulate, in the context of the present invention is understood to mean a particulate mixture of precursor substances, in particular starting compounds, preferably precursors, which react to form the desired target compounds.

Solid-in-liquid precursor material mixtures or liquid-in-liquid precursor material mixtures, in particular a precursor dispersion, preferably a precursor sol, is to be understood in the context of the present invention as a solution or dispersion of precursor substances, in particular starting compounds, preferably precursors, which lead to react to the desired target connections.

In such precursor material mixtures, in particular precursor dispersions, preferably precursor sols, the chemical compounds or mixtures of chemical compounds are no longer necessarily in the form of the originally used chemical compounds, but for example as hydrolyzates, condensates or other reaction or intermediate products.

This is particularly illustrated by the preferred expression of the “sol”. In the context of sol-gel processes, inorganic materials are usually converted into reactive intermediates or agglomerates and particles, the so-called sol, by hydrolysis or solvolysis, which then age to form a gel, in particular through a condensation reaction, with larger particles and agglomerates in the Solution or dispersion arise. By choosing a suitable concentration or adding or dispensing with reactor accelerators and catalysts, the physical properties of the sol or gel, in particular also particle sizes, can be adjusted in such a way that it can be processed in conventional printing processes. A precursor sol can therefore also be understood to mean gels in the context of the present invention.

In the context of the present invention, a solution is to be understood as meaning a usually liquid single-phase system in which at least one substance, in particular a compound or its building blocks, such as ions, is homogeneously distributed in a further substance, the so-called solvent.

In the context of the present invention, a dispersion is to be understood as an at least two-phase system, a first phase, namely the dispersed phase, being present in a distributed manner in a second phase, the continuous phase. The continuous phase is also referred to as the dispersion medium or dispersant. In the context of the present invention, the continuous phase is usually in the form of a liquid, so that dispersions in the context of the present invention are therefore generally solid-in-liquid or liquid-in-liquid dispersions.

In particular in the case of brines or also in the case of polymeric compounds, the transition from a solution to a dispersion is often fluid and it is no longer possible to clearly differentiate between a solution and a dispersion.

It is also possible within the scope of the present invention, depending on the selection of the precursor material, to produce different SiC-containing materials or different silicon carbide, namely stoichiometric, non-stoichiometric, doped or alloyed silicon carbide or SiC-containing material.

In the context of the present invention, a stoichiometric silicon carbide or SiC-containing material is to be understood as a material which contains carbon and silicon at least essentially in the molar silicon-to-carbon ratio in a range around 1: 1.

In the context of the present invention, a non-stoichiometric silicon carbide is to be understood as meaning a silicon carbide which does not contain carbon and silicon in a molar ratio of 1: 1. In the context of the present invention, a non-stoichiometric silicon carbide usually has a molar excess of silicon.

In the context of the present invention, doped silicon carbide is generally to be understood as meaning a silicon carbide which, in addition to silicon and carbon, has further, in particular intercalating, doping elements.

Alloyed silicon carbide in the context of the present invention is generally to be understood as meaning a silicon carbide which, in addition to silicon and carbon, has one or more alloying elements.

Depending on the SiC-containing structure to be produced or the silicon carbide to be produced as well as the application and application conditions of the precursor material, the composition of the precursor material can therefore vary within wide ranges.

If a stoichiometric silicon carbide is to be produced within the scope of the present invention, it has proven useful that the precursor material has an at least essentially stoichiometric silicon-to-carbon ratio, in particular a silicon-to-carbon quantity ratio in the range of 35:65 wt % to 65: 35% by weight, preferably 40: 60% by weight to 60: 40% by weight, preferably 45:55% by weight to 55:45% by weight, particularly preferably 50:50 % By weight, based on the precursor material.

x =

0,05 bis 0,8, insbesondere 0,07 bis 0,5, vorzugsweise 0,09 bis 0,4, bevorzugt 0,1 bis 0,3.

If, within the scope of the present invention, a non-stoichiometric silicon carbide is to be produced, the non-stoichiometric silicon carbide is usually a silicon carbide of the general formula (I) SiC _1-x with (I)

x =

0.05 to 0.8, in particular 0.07 to 0.5, preferably 0.09 to 0.4, preferably 0.1 to 0.3.

The correspondingly obtainable silicon-rich silicon carbides have a particularly high mechanical strength and are suitable for a large number of applications as ceramics.

1. (A) die Silicium-Quelle in Mengen von 60 bis 90 Gew.-%, insbesondere 65 bis 85 Gew.-%, vorzugsweise 70 bis 80 Gew.-%, und
2. (B) die Kohlenstoff-Quelle in Mengen von 10 bis 40 Gew.-%, insbesondere 15 bis 35 Gew.-%, vorzugsweise 20 bis 30 Gew.-%,

jeweils bezogen auf das Precursormaterial.If a non-stoichiometric silicon carbide is produced with the precursor material, the precursor material usually contains it

1. (A) the silicon source in amounts of 60 to 90% by weight, in particular 65 to 85% by weight, preferably 70 to 80% by weight, and
2. (B) the carbon source in amounts of 10 to 40% by weight, in particular 15 to 35% by weight, preferably 20 to 30% by weight,

each based on the precursor material.

In the context of the present invention, precursor materials which are intended to be used to produce non-stoichiometric silicon carbide or SiC-containing material thus generally have a comparatively higher proportion of the silicon source than the carbon source.

It has also preferably proven useful if the precursor material has a silicon-to-carbon ratio in the range from 65:35% by weight to 85:15% by weight, preferably 70:30% by weight to 80:20% by weight %, preferably 72:28% by weight to 78:22% by weight, based on the precursor material.

It is also possible within the scope of the present invention to carry out the method for producing SiC-containing material or SiC-containing structures in such a way that the silicon carbide-containing compound produced contains a silicon carbide alloy or is a silicon carbide alloy.

As regards the silicon carbide alloy, the silicon carbide alloy is usually selected from MAX phases, alloys of silicon carbide with elements, particularly metals, and alloys of silicon carbide with metal carbides and / or metal nitrides. Such silicon carbide alloys contain silicon carbide in varying and strongly fluctuating proportions. In particular, it can be provided that silicon carbide is the main component of the alloys. However, it is also possible that the silicon carbide alloy contains silicon carbide only in small amounts.

The silicon carbide alloy usually contains the silicon carbide, in particular the elements silicon and carbon, in amounts of 10 to 95% by weight, in particular 15 to 90% by weight, preferably 20 to 80% by weight, based on the silicon carbide alloy.

In the context of the present invention, a MAX phase is _{understood to mean, in particular, carbides and nitrides of the general formula M n + 1} AX _n with n = 1 to 3 which crystallize in hexagonal layers. M stands for an early transition metal from the third to sixth group of the Periodic Table of the Elements, while A stands for an element of the 13th to the 16th group of the Periodic Table of the Elements. After all, X is either carbon or nitrogen. In the context of the present invention, however, only those MAX phases are of interest whose empirical formula contains silicon carbide (SiC), ie silicon and carbon.

MAX phases have unusual combinations of chemical, physical, electrical and mechanical properties, as they show both metallic and ceramic behavior depending on the conditions. This includes, for example, high electrical and thermal conductivity, high resistance to thermal shock, very high levels of hardness and low coefficients of thermal expansion.

When the silicon carbide alloy is a MAX phase, it is preferred if the MAX phase is selected from Ti ₄ SiC ₃ and Ti ₃ SiC.

If the SiC-containing compound is an alloy of silicon carbide, in the event that the alloy is an alloy of silicon carbide with metals, it has proven useful if the alloy is selected from alloys of silicon carbide with metals from the group of Al, Ti, V, Cr, Mn, Co, Ni, Zn, Zr and their mixtures.

If the alloy of silicon carbide is selected from alloys of silicon carbide with metal carbides and / or nitrides, it has proven useful if the alloys of silicon carbide with metal carbides and / or nitrides is selected from the group of boron carbides, in particular B ₄ C, chromium carbides, especially Cr ₂ C ₃ , titanium carbides, especially TiC, molybdenum carbides, especially Mo ₂ C, niobium carbides, especially NbC, tantalum carbides, especially TaC, vanadium carbides, especially VC, zirconium carbides, especially ZrC, tungsten carbides, especially WC, boron nitride, especially BN, and their Mixtures.

1. (A) die Silicium-Quelle in Mengen von 5 bis 40 Gew.-%, insbesondere 5 bis 30 Gew.-%, vorzugsweise 10 bis 20 Gew.-%,
2. (B) die Kohlenstoff-Quelle in Mengen von 10 bis 60 Gew.-%, insbesondere 15 bis 50 Gew.-%, vorzugsweise 20 bis 50 Gew.-%, und
3. (C) einen oder mehrere Precursoren für Legierungselemente in Mengen von 5 bis 70 Gew.-%, insbesondere 5 bis 65 Gew.-%, vorzugsweise 10 bis 60 Gew.-%, jeweils bezogen auf das Precursormaterial. Falls im Rahmen des erfindungsgemäßen Verfahrens das Precursormaterial zur Herstellung von dotiertem Siliciumcarbid eingesetzt werden soll, so kann es vorgesehen sein, dass dem Precursormaterial ein Dotierungsreagenz zugesetzt wird. Im Rahmen dieser besonderen Ausführungsform der vorliegenden Erfindung hat es sich als vorteilhaft erwiesen, wenn das Dotierungsreagenz in Mengen von 0,000001 bis 15 Gew.-%, insbesondere 0,000001 bis 10 Gew.-%, vorzugsweise 0,000005 bis 5 Gew.-%, bevorzugt 0,00001 bis 1 Gew.-%, bezogen auf die Mischung, zugesetzt wird.

If the precursor material is to be used to produce a silicon carbide alloy, then the precursor material usually contains

1. (A) the silicon source in amounts of 5 to 40% by weight, in particular 5 to 30% by weight, preferably 10 to 20% by weight,
2. (B) the carbon source in amounts of 10 to 60% by weight, in particular 15 to 50% by weight, preferably 20 to 50% by weight, and
3. (C) one or more precursors for alloy elements in amounts of 5 to 70% by weight, in particular 5 to 65% by weight, preferably 10 to 60% by weight, each based on the precursor material. If, within the scope of the method according to the invention, the precursor material is to be used to produce doped silicon carbide, it can be provided that the precursor material contains a Doping reagent is added. In the context of this particular embodiment of the present invention, it has proven to be advantageous if the doping reagent is used in amounts of 0.000001 to 15% by weight, in particular 0.000001 to 10% by weight, preferably 0.000005 to 5% by weight. -%, preferably 0.00001 to 1% by weight, based on the mixture, is added.

As far as the chemical nature of the doping reagent is concerned, it can be selected from common suitable doping elements. The doping reagent or the doping element is preferably selected from elements of the third and fifth main groups of the periodic table.

It has also proven to be advantageous if the doping reagent is suitable for n- or p-doping, in particular is selected from the group of the elements nitrogen, phosphorus, boron, aluminum and indium, and mixtures thereof.

If doping with nitrogen is provided, the solution can contain nitric acid, ammonium chloride or melanin. If doping with phosphorus is provided, for example phosphoric acid or phosphates or phosphonic acids can be used. In addition, nitrogen doping is also possible by performing the method according to the invention in a nitrogen atmosphere.

If doping with boron is provided, for example boric acids, borates or boron salts, such as boron trichloride, are used.

If indium is doped, water-soluble indium salts, such as indium chloride, are usually used as the doping reagent.

The silicon carbide produced with the method according to the invention, in particular the SiC-containing material, can therefore, as stated, be selected within the scope of the present invention from stoichiometric silicon carbide, doped stoichiometric silicon carbide, non-stoichiometric silicon carbide, doped non-stoichiometric silicon carbide and silicon carbide alloys. With the method according to the invention, a large number of different SiC-containing materials, in particular different silicon carbide compounds, is thus accessible.

The person skilled in the art is familiar with the suitable precursor materials. For example, the DE 10 2017 110 362 A1 or. WO 2018/206645 A1 a solid precursor material, in particular a precursor granulate, which is preferably obtained by a sol-gel process with subsequent reductive thermal treatment and is excellently suited for the production of a wide variety of SiC-containing materials in powder bed processes.

Furthermore describes the DE 10 2018 127 877.2 an optimized manufacturing process for a solid precursor material, which makes it possible to reproducibly obtain a defined, uniformly composed SiC precursor granulate. The granules can be used both in processes that are carried out as solid processes, in particular powder bed processes, and in the form of solid-in-liquid dispersions.

The DE 10 2017 110 361 A1 or. WO 2018/206643 A1 describe the production of precursor materials in the form of solutions or dispersions, in particular precursor sols, which are suitable for use in printing processes, in particular inkjet printing processes.

In general, it is provided that the precursor material for producing the SiC-containing materials is present as a precursor powder, in particular as a granular precursor powder, or as a precursor dispersion, in particular as a solid-in-liquid precursor dispersion.

In the context of the present invention it is also usually preferred if the precursor powder or the precursor dispersion consists of homogeneous particles, in particular microparticles, preferably nanoparticles, or contains them, preferably consists of them.

According to a preferred embodiment of the present invention, it has proven to be advantageous if the precursor powder or the precursor dispersion consists of composite particles, in particular homogeneous composite particles, preferably composite particles with a core-shell structure (core-shell structure), or contains these, preferably consists of this.

In the context of the present invention, composite particles with a core-shell structure (core-shell structure) are generally understood to mean particles which have an inner core and an outer shell. The inner core can be formed, for example, by the silicon sources, in particular, for example, elemental silicon, so that, analogously, the outer shell is formed by the carbon source, in particular, for example, at least one organic carbon compound.

According to a preferred embodiment of the present invention, it is provided that the precursor material is a solid-in-solid Precursor material mixture, in particular a precursor powder, preferably a precursor granulate. These precursors or precursor mixtures are particularly suitable for use in powder bed processes.

According to a very particularly preferred embodiment of the present invention, it can also be provided that the precursor material is a precursor material mixture having a crystalline component, in particular a precursor powder having a crystalline component. A particularly suitable such precursor powder is in DE 10 2019 121 062.3 disclosed.

In particular if the precursor material having a crystalline constituent is present as, in particular granular, precursor powder, it is preferably provided in the context of this embodiment of the present invention that the precursor material is composed of homogeneous particles, in particular microparticles, preferably nanoparticles, and these particles preferably composite particles, in particular homogeneous composite particles, preferably composite particles with a core-shell structure (core-shell structure), are or contain these.

The precursor materials composed in this way, in particular precursor powders composed in this way, are distinguished by an overall high degree of homogeneity. In the context of the production of silicon carbide according to the method according to the present invention, this circumstance allows particularly good conversions and the formation of silicon carbide of particularly uniform composition with regard to the quantitative ratio between carbon and silicon.

Furthermore, it was observed, in particular for the use of composite particles, that a homogeneous size distribution within the particles on the one hand and a homogeneous component distribution with regard to the silicon source and the carbon source on the other hand can ideally be achieved through core-shell structures.

In general, particularly good results are also obtained in the context of the present invention if the precursor material has particle sizes in the range from 0.1 μm to 1,500 μm, in particular 0.1 μm to 1,000 μm, preferably 0.5 μm to 800 μm, preferably 1 μm up to 600 µm.

It has also proven to be advantageous if the solid-in-solid precursor material mixtures, in particular the precursor powder, have particle sizes in the range from 0.1 to 1,000 μm, in particular 0.5 to 500 μm, preferably 1 to 200 μm, preferably 10 to 100 µm, particularly preferably 40 to 80 µm, in particular if the process according to the invention is carried out as a solid process, in particular a powder bed process.

Furthermore, it can be provided within the scope of the present invention that the layer of the precursor material for solid-in-solid precursor material mixtures, in particular precursor powder, preferably has a layer thickness in the range from 1 to 1,000 μm, in particular 2 to 500 μm, preferably 5 to 250 μm 10 to 180 μm, particularly preferably 20 to 150 μm, very particularly preferably 20 to 100 μm when the process according to the invention is carried out as a solid process.

In the context of the present invention, in particular of the production method according to the invention, it is alternatively preferred that a solid-in-liquid precursor material mixture or liquid-in-liquid precursor material mixture, in particular a precursor dispersion, preferably a precursor sol, is used.

With regard to the selection of the solvent or dispersant in the precursor material mixture according to the invention, in particular precursor dispersion or precursor sol, this can be selected from all suitable solvents or dispersants. Usually, however, the solvent or dispersant is selected from water and organic solvents and mixtures thereof.

Particularly in the case of mixtures which contain water, the starting compounds which are usually hydrolyzable or solvolyzable are converted to inorganic hydroxides, in particular metal hydroxides and silicas, which then condense so that solid-in-liquid or liquid-in-liquid suitable for printing processes. Precursor material mixtures, in particular precursor dispersions or precursor sols, from which SiC-containing compounds can be produced, are present. Alternatively, however, elemental silicon can also be used in a dispersant or composite particles containing a carbon source, in particular sucrose or invert sugar syrup, which have a carbon and a silicon source and are present in a suitable solvent or dispersant.

The starting compounds used should also have sufficiently high solubilities in the solvents used, in particular in ethanol and / or water, in order to be able to form finely divided dispersions or solutions, in particular sols, and must not be mixed with other components of the solution or the during the production process Dispersion, especially the sol, react to form insoluble compounds. In addition, the reaction speed of the individual reactions taking place must be coordinated with one another, since the hydrolysis, condensation and in particular the gelation should take place undisturbed as far as possible in order to obtain the most homogeneous possible distribution of the individual components in the sol or gel. Furthermore, the reaction products formed must not be sensitive to oxidation and, moreover, should not be volatile.

In the context of the present invention it can also be provided that the organic solvent is selected from alcohols, in particular methanol, ethanol, 2-propanol, acetone, ethyl acetate and mixtures thereof. It is particularly preferred in this context if the organic solvent is selected from methanol, ethanol, 2-propanol and mixtures thereof, with ethanol being particularly preferred.

The above-mentioned organic solvents are miscible with water over a wide range and in particular are also suitable for dispersing or dissolving polar inorganic substances, such as, for example, metal salts.

As already stated above, mixtures of water and at least one organic solvent, in particular mixture of water and ethanol, are preferably used as solvents or dispersants in the context of the present invention. In this context, it is preferred if the solvent or dispersant has a weight ratio of water to organic solvent of 1:10 to 20: 1, in particular 1: 5 to 15: 1, preferably 1: 2 to 10: 1, preferably 1 : 1 to 5: 1, particularly preferably 1: 3. Through the ratio of water to organic solvent, on the one hand, the rate of hydrolysis and, on the other hand, the solubility and reaction rate of both the silicon source and the carbon source can be adjusted.

The amount in which the precursor mixture contains the solvent or dispersant can vary within a wide range depending on the particular application conditions and the type of SiC-containing compound to be produced - as already stated above. Usually, however, the solid-in-liquid or liquid-in-liquid precursor material mixture, in particular the precursor dispersion, the solvent or dispersant in amounts of 10 to 80% by weight, in particular 15 to 75% by weight, preferably 20 to 70% by weight, preferably 20 to 65% by weight, based on the composition.

According to a preferred embodiment of the present invention, several different precursor material mixtures, in particular precursor dispersions or precursor sols, can also be used. In particular with printing processes, such as, for example, inkjet processes, different precursor materials can be used in areas in a layer or layer of the precursor material. In this way, SiC-containing structures can be obtained, the mechanical and electrical properties of which can be set in a targeted manner in certain areas or locally. In particular, mechanically particularly stressed zones of ceramic components can thus be specifically reinforced or, for example, conductor tracks can be produced in a component. Furthermore, it is also possible in this way to produce sophisticated semiconductor structures. Suitable printing processes are based, for example, on the simultaneous print application of different precursor materials, in particular through different nozzles of a print head in the inkjet process, or on the immediate successive printing of different precursor materials by means of one or more print heads, the simultaneous print application being preferred. Such printing processes are however familiar to the person skilled in the art and are in particular in the DE 10 2017 110 361 A1 or the WO 2018/206643 A1 described.

If the process according to the invention is carried out as a liquid printing process, it has proven to be advantageous in the context of this preferred embodiment of the present invention if the solid-in-liquid precursor material mixture or the liquid-in-liquid precursor material mixture, in particular the precursor dispersion, has a Brookfield dynamic viscosity at 25 ° C. in the range from 3 to 500 mPas, in particular from 4 to 200 mPas, preferably from 5 to 100 mPas. In the context of the present invention, it is therefore preferred if highly viscous precursor material mixtures, in particular precursor dispersions, which are, however, also suitable for spray or print application, are used, since in this way even protruding structures are accessible to a certain extent without support structures.

It has also proven to be advantageous if the layer of the precursor material for solid-in-liquid precursor material mixtures or liquid-in-liquid precursor material mixtures, in particular precursor dispersions, has a layer thickness in the range from 0.1 to 250 μm, in particular 0.2 to 100 μm, preferably 0.5 to 50 μm, preferably 1 to 25 μm, if the method according to the invention is carried out as a liquid printing method.

As far as the type of silicon source is concerned, it can generally consist of a large number of materials or chemical Connections must be selected. In the context of the present invention, however, it has proven particularly useful if the silicon source is selected from the group of silanes, silane hydrolysates, silicates, silica sols, orthosilicic acids, water glasses, elemental silicon and their mixtures, in particular silanes, silane hydrolysates, elemental silicon , and their mixtures.

Orthosilicic acid and its condensation products can be obtained, for example, from alkali silicates, the alkali metal ions of which have been exchanged for protons by ion exchange. In the context of the present invention, alkali metal compounds are, if possible, not used in the precursor material, since they are also incorporated into the SiC-containing compound. Accordingly, alkali metal doping is generally not desired in the context of the present invention. However, if this should be desired, suitable alkali metal salts, for example those of the silicon source or else alkali metal phosphates, can be used.

R =

Alkyl, insbesondere C₁- bis C₅-Alkyl, vorzugsweise C₁- bis C₃-Alkyl, bevorzugt C₁- und/oder C₂-Alkyl; Aryl, insbesondere C₆- bis C₂₀-Aryl, vorzugsweise C₆- bis C₁₅-Aryl, bevorzugt C₆- bis C₁₀-Aryl; Olefin, insbesondere terminales Olefin, vorzugsweise C₂- bis C₁₀-Olefin, bevorzugt C₂- bis C₈-Olefin, besonders bevorzugt C₂- bis C₅-Olefin, ganz besonders bevorzugt C₂- und/oder C₃-Olefin, insbesondere bevorzugt Vinyl; Amin, insbesondere C₂- bis C₁₀-Amin, vorzugsweise C₂- bis C₈-Amin, bevorzugt C₂- bis C₅-Amin, besonders bevorzugt C₂- und/oder C₃-Amin; Carbonsäure, insbesondere C₂- bis C₁₀-Carbonsäure, vorzugsweise C₂- bis C₈-Carbonsäure, bevorzugt C₂- bis C₅-Carbonsäure, besonders bevorzugt C₂- und/oder C₃-Carbonsäure; Alkohol, insbesondere C₂- bis C₁₀-Alkohol, vorzugsweise C₂- bis C₈-Alkohol, bevorzugt C₂- bis C₅-Alkohol, besonders bevorzugt C₂- und/oder C₃-Alkohol;

X =

Halogenid, insbesondere Chlorid und/oder Bromid; Alkoxy, Insbesondere C₁- bis C₆-Alkoxy, besonders bevorzugt C₁- bis C₄- Alkoxy, ganz besonders bevorzugt C₁- und/oder C₂-Alkoxy; und

n =

1-4, vorzugsweise 3 oder 4.

If, in the context of the present invention, a silane is used as the silicon source, it has proven useful if the silane is selected from silanes of the general formula II R _4-n SiX _n with (II)

R =

Alkyl, in particular C ₁ - to C ₅ -alkyl, preferably C ₁ - to C ₃ -alkyl, preferably C ₁ - and / or C ₂ -alkyl; Aryl, in particular C ₆ to C ₂₀ aryl, preferably C ₆ to C ₁₅ aryl, preferably C ₆ to C ₁₀ aryl; Olefin, in particular terminal olefin, preferably C ₂ to C ₁₀ olefin, preferably C ₂ to C ₈ olefin, particularly preferably C ₂ to C ₅ olefin, very particularly preferably C ₂ and / or C ₃ olefin , particularly preferably vinyl; Amine, in particular C ₂ to C ₁₀ amine, preferably C ₂ to C ₈ amine, preferably C ₂ to C ₅ amine, particularly preferably C ₂ and / or C ₃ amine; Carboxylic acid, in particular C ₂ to C ₁₀ carboxylic acid, preferably C ₂ to C ₈ carboxylic acid, preferably C ₂ to C ₅ carboxylic acid, particularly preferably C ₂ and / or C ₃ carboxylic acid; Alcohol, in particular C ₂ to C ₁₀ alcohol, preferably C ₂ to C ₈ alcohol, preferably C ₂ to C ₅ alcohol, particularly preferably C ₂ and / or C ₃ alcohol;

X =

Halide, especially chloride and / or bromide; Alkoxy, in particular C ₁ to C ₆ alkoxy, particularly preferably C ₁ to C ₄ alkoxy, very particularly preferably C ₁ and / or C ₂ alkoxy; and

n =

1-4, preferably 3 or 4.

R =

C₁- bis C₃-Alkyl, insbesondere C₁- und/oder C₂-Alkyl; C₆- bis C₁₅-Aryl, insbesondere C₆- bis C₁₀-Aryl; C₂- und/oder C₃-Olefin, insbesondere Vinyl;

X =

Alkoxy, Insbesondere C₁- bis C₆-Alkoxy, besonders bevorzugt C₁- bis C₄- Alkoxy, ganz besonders bevorzugt C₁- und/oder C₂-Alkoxy; und

n =

3 oder 4.

However, particularly good results are obtained when the silane is selected from silanes of the general formula IIa R _4-n SiX _n with (IIa)

R =

C ₁ - to C ₃ -alkyl, in particular C ₁ - and / or C ₂ -alkyl; C ₆ to C ₁₅ aryl, in particular C ₆ to C ₁₀ aryl; C ₂ and / or C ₃ olefin, in particular vinyl;

X =

Alkoxy, in particular C ₁ to C ₆ alkoxy, particularly preferably C ₁ to C ₄ alkoxy, very particularly preferably C ₁ and / or C ₂ alkoxy; and

n =

3 or 4.

By hydrolysis and subsequent condensation reaction of the aforementioned silanes, condensed orthosilicic acids or siloxanes can also be obtained in a simple manner, which have only very small particle sizes, and further elements, in particular metal hydroxides, can also be incorporated into the basic structure.

Particularly good results are obtained in the context of the present invention when the silicon source is selected from tetraalkoxysilanes, trialkoxysilanes and mixtures thereof, preferably tetraethoxysilane, tetramethoxysilane or triethoxymethylsilane and mixtures thereof.

If, on the other hand, elemental silicon is used as the silicon source, it has proven useful in this case if the elemental silicon is used in the form of a powder, in particular in the form of a microscale powder, preferably in the form of a nanoscale powder.

According to this embodiment of the present invention, it has also proven useful if the elemental silicon is used in the form of particles, in particular in the form of microparticles, preferably in the form of nanoparticles.

In this context, it is particularly preferred if the elemental silicon is used in the form of monocrystalline particles, in particular in the form of monocrystalline microparticles, preferably in the form of monocrystalline nanoparticles.

The use of elemental silicon in the aforementioned powdery, in particular particulate, nature favors the homogeneous Distribution of the elemental silicon in the precursor material. A homogeneous distribution of the material constituents enables, overall, the efficient implementation of the precursor material within the scope of the method according to the invention.

According to this embodiment of the present invention, it can also be provided that the elemental silicon is obtained from reusable raw material sources and / or comes from excess material residues from silicon processing.

It is also preferred for this embodiment if elemental silicon with a degree of purity of at least 95%, in particular at least 98%, preferably at least 99%, preferably at least 99.5%, is used. This makes it possible on the one hand to obtain highly pure and defined silicon carbide ceramics, on the other hand it is also possible to produce silicon carbides with specific and preselected electrical properties.

As for the silicon source, it is also generally possible with regard to the carbon source that it can be selected from a large number of materials or compounds, in particular depending on the precursor material and the desired silicon carbide or SiC-containing material. In the context of the present invention, however, it has proven particularly advantageous if the carbon source is selected from the group of carbohydrates, in particular glucose, fructose, invert sugar, sucrose, maltose, lactose, amylose, amylopectin, starch, starch derivatives, or from the group of organic polymers, in particular phenol-formaldehyde resin and resorcinol-formaldehyde resin, and mixtures thereof.

In the context of the present invention, it is particularly preferred if the carbon source is selected from the group of sugars, in particular sucrose, glucose, fructose, invert sugar, maltose, starch, starch derivatives, organic polymers, in particular phenol-formaldehyde resin and resorcinol-formaldehyde resin , and their mixtures.

Particularly good results are obtained in the context of the present invention when the carbon source is selected from the group of sugars, starch, starch derivatives and mixtures thereof, preferably sugars, since the use of sugars and starch or starch derivatives in particular increases the viscosity of the Allow the composition, on the one hand, and the stickiness of the composition, on the other hand, to be adjusted in a targeted manner, which is particularly advantageous when using precursor sols and liquid precursor dispersions.

In order to improve the solubility or dispersibility and miscibility of the carbon source in the precursor material, it can be provided that the carbon source, in particular selected from sugars or starch, is dissolved or predispersed in a small amount of solvent or dispersant, whereupon this solution or dispersion is processed further into the actual precursor material. In this context, it has proven useful if the carbon source is used in a solution or dispersion which contains the carbon source in amounts of 10 to 90% by weight, in particular 30 to 85% by weight, preferably 50 to 80% % By weight, in particular 60 to 70% by weight, based on the solution or dispersion of the carbon source.

If necessary, this dissolving and dispersing process, after the carbon and silicon sources have been combined, can be followed by a drying step to form the actual precursor material, in which the solvent or dispersant is again removed.

In the context of an alternative, preferred embodiment of the present invention, in particular for the case that the silicon source is elemental silicon, it can also be provided that the carbon source is an organic carbon compound of the type described below.

In the context of this alternative, preferred embodiment of the present invention, an organic carbon compound is understood to mean a compound which is composed predominantly of the elements carbon, hydrogen and oxygen. However, to a small extent, other heteroatoms such as nitrogen, sulfur or phosphorus can also be contained in the organic carbon compound, these heteroatoms only being desirable if doping of the silicon carbide is to be achieved.

With regard to the form of the organic carbon compound, in the context of this embodiment of the present invention it is preferably provided that the carbon compound is used in liquid form.

This means that the organic carbon compound, if it is present as a solid, is first brought into solution and only then is used for the production of the corresponding precursor material. If the organic carbon compound is already in the form of a liquid or at least essentially in liquid form, it is used as such directly for the manufacturing process. The In this context, organic carbon compounds can in particular be present in a liquid or in the form of a liquid solution or dispersion which contain the organic carbon compound, as explained below. The organic carbon compound in liquid form is preferably suitable for forming a homogeneous dispersion with the elemental silicon, in particular in the form of a nano- or microscale powder.

According to this embodiment, it is also preferably provided that the organic carbon compound is a polymer or an oligomer or monomer.

In the context of the present invention, a monomer is generally understood to mean a low molecular weight, reactive molecular unit which can be converted in polyreactions to form higher molecular weight compounds such as oligomers or polymers. In the context of polyreactions, structurally identical or structurally similar, at least similarly reactive, monomers are linked to one another via reactive groups such as multiple bonds or functional groups and thus form the basic units of an oligomer or polymer. Exemplary polyreactions can be polycondensations, polyadditions and radical or coordinative polymerizations, without wishing to limit the type of possible polyreactions by this list.

In the context of the present invention, an oligomer is understood to mean a molecule that results from monomers reacted with one another in a polyreaction. For the purposes of the invention, an oligomer is composed of at least two monomer units. These monomer units can be the same or different, so that homooligomers or heterooligomers are obtained. As a rule, it is provided that, within the scope of the invention, oligomers have a definable number of repeating units, in particular between two and 50 repeating units.

In the context of the present invention, polymers are understood to mean macromolecular compounds which are built up in a polyreaction from one or more different monomers. The term polymer therefore includes both homopolymers and heteropolymers; Homopolymers are obtained by reacting the same monomers and heteropolymers are obtained by reacting different monomers. Furthermore, polymers can have a relatively broad distribution of the monomeric repeat units. Overall, for the purposes of the invention, polymers are characterized by a number of monomer units that is difficult to define and have high average molecular weights.

If the organic carbon compound in this alternative, preferred embodiment is a polymer or oligomer, the organic carbon compound is preferably characterized in that the polymer or oligomer is selected from the group of polyethers, polyethylene glycols, polysaccharides, polyketones, polyether ketones, and polyesters , Polycarbonates, polyhydroxyalkanoates and their mixtures, in particular polyethers, polysaccharides, polyesters, polycarbonates and their mixtures, preferably a polysaccharide. If the organic carbon compound is a monomer, it has proven useful if the monomer is a monomer for producing the aforementioned polymers or oligomers, in particular selected from the group of ethers, saccharides, esters, carbonates, carboxylic acids and mixtures thereof, preferably a saccharide is.

It is particularly preferred in the context of this embodiment of the invention if the organic carbon compound, in particular the polymer or oligomer, has ether, carbonyl, acetal, ester and / or carbonate repeat units.

Organic carbon compounds of the aforementioned nature and composition show in the context of this embodiment of the present invention an advantageous mixing behavior with the elemental silicon in the course of the production of the precursor material as well as excellent properties in the production of silicon carbide from the precursor material, since they contain in particular carbon, hydrogen and oxygen and thus possibly forming by-products which are preferably highly volatile and do not reduce the quality of the silicon carbide produced.

Furthermore, in the context of this embodiment of the present invention, it can preferably be provided that the organic carbon compound, in particular the polymer or oligomer or monomer, is linear and / or branched and / or cyclic. Branched or cyclic monomers can occur in particular when using sugars or other substances that can react to form oligomers or polymers.

In addition, it is preferred according to this embodiment if the organic carbon compound, in particular the polymer or oligomer or monomer, has functional groups, in particular hydroxyl groups, in addition to the repeating units.

Furthermore, according to this embodiment, it is particularly preferred if the organic Carbon compound is present as a heterogeneous mixture, in particular as a heterogeneous mixture of monomers and monomer condensate, preferably as a heterogeneous mixture of monomer and dimeric, oligomeric or polymeric monomer condensate.

In particular, it is preferred in the context of this embodiment of the present invention if the organic carbon compound, in particular the polymer or oligomer or monomer, is a polyalcohol.

In this context it is particularly preferred if the polyalcohol is a saccharide.

In the context of this embodiment, it is again particularly preferred if the saccharide is selected from the group of hexoses or pentoses or mixtures thereof.

The use of saccharides as a special form of the organic carbon compound according to this particular embodiment of the present invention is particularly advantageous in that saccharides have a particularly balanced ratio between carbon, hydrogen and oxygen and thus in the context of this embodiment of the production process according to the invention of silicon carbide show ideal reaction behavior. Above all, it should be emphasized here that saccharides enable the formation of particularly pure silicon carbide, since apart from carbon only volatile by-products are released, in particular water.

In the context of this embodiment of the present invention, it has proven particularly useful if the saccharide is selected from the group of glucose and its stereoisomers, fructose and its stereoisomers, xylose and its stereoisomers, the disaccharides of the aforementioned compounds, in particular glucose and / or fructose, preferably glucose and fructose, the oligosaccharides of the aforementioned compounds, in particular glucose and / or fructose, the polysaccharides of the aforementioned compounds, in particular glucose, or mixtures thereof.

It is also preferably provided here if the saccharide is in the form of a liquid, in particular in the form of a syrup, preferably in the form of a highly concentrated syrup.

In the context of the present invention, a highly concentrated syrup is understood to mean an aqueous solution of the saccharide with a water content of less than 25% by weight, based on the total amount of the syrup. Aqueous saccharide solutions with a water content equal to or greater than 25% by weight are regarded as syrups.

In the context of this alternative, preferred embodiment of the method according to the invention, it is also very particularly preferred if the saccharide is invert sugar syrup.

Invert sugar syrup in the context of the invention means an aqueous solution of sucrose or starch which has been partially inverted by hydrolysis. Usually the invert sugar syrup in this connection can contain varying proportions of the glucose and fructose obtained by partial hydrolysis. These proportions are preferably between 5 to 95% for glucose and accordingly between 95 to 5% for fructose, based on the total amount of monosaccharides in the invert sugar syrup.

This is because it has been found for this special embodiment that elemental silicon can be mixed so well with invert sugar syrup that a particularly homogeneous distribution of elemental silicon in powder or particle form can be achieved. This forms the ideal prerequisites for the provision of a uniformly composed and reproducible and controllable high-quality precursor material from which silicon carbide can subsequently be produced efficiently and reliably by the method according to the invention.

To provide the precursor material according to this special embodiment of the present invention, it is now initially provided that elemental silicon is mixed with at least one organic carbon compound, in particular the mixture of elemental silicon and organic carbon compound being in the form of a, preferably homogeneously distributed, dispersion.

In addition, according to this specific embodiment of the present invention, it is preferred if the dispersion of elemental silicon and organic carbon compound is converted into a powder, in particular a precursor powder, by drying, in particular afterwards. In this context, it is advantageous if the dispersion is converted into a powder, in particular a precursor powder, with the supply of heat and / or reduction in pressure, in particular with supply of heat and reduction in pressure and stirring.

Finally, according to this special embodiment, in the course of the production of the precursor material, it has proven to be advantageous that by comminuting, in particular crushing, preferably grinding, preferably grinding, is converted into a powder, in particular a microscale powder, preferably a nanoscale powder.

In general, it can furthermore be preferred within the scope of the present invention if the reaction of the precursor material is carried out under a protective gas atmosphere, in particular a nitrogen and / or argon atmosphere, preferably an argon atmosphere, as already indicated above.

In the context of the present invention, a protective gas is understood to mean a gas which effectively prevents the oxidation of the constituents of the carbon and silicon source by, in particular, atmospheric oxygen.

According to a further preferred embodiment of the present invention, it has also proven to be expedient if the SiC-containing structure obtained is cleaned and / or reworked in a final process step (c).

Last but not least, within the scope of the present invention it is preferably provided that the manufacturing method is a generative manufacturing method, in particular a printing bed-based generative manufacturing method.

For the relevant details on the respective implementation of the generative manufacturing process, reference should be made at this point to the following patent applications, relating to each generative manufacturing process, in particular based on the selective synthetic crystallization: special reference is made to powder bed-based processes, as in the DE 10 2017 110 362 A1 or. WO 2018/206645 A1 described, and on inkjet processes, as in the DE 10 2017 110 361 A1 or. WO 2018/206643 A1 described. The method according to the invention can therefore be carried out in analogy to the generative manufacturing methods mentioned, taking into account the features and special features according to the invention, and is thus characterized in particular by the fact that it can be set up flexibly and variably.

With the method according to the invention, as in the DE 10 2017 110 362 A1 or. WO 2018/206645 A1 described, powdery SiC precursor materials are converted to silicon carbide-containing materials, in particular non-stoichiometric silicon-rich silicon carbides and silicon carbide alloys, for which purpose a device based on selective laser sintering (SLS) or selective laser melting (SLM) is used becomes. A particular advantage of this procedure is that, in particular, homogeneous, compact, three-dimensional bodies can be obtained which do not have to be subjected to any subsequent sintering.

Last but not least, the method according to the invention, based on selective synthetic crystallization, can also be based on 3D printing techniques, in particular in inkjet processes, in combination with the targeted input of energy into the material in analogy to DE 10 2017 110 361 A1 or. WO 2018/206643 A1 be performed.

An advantage of this special embodiment of the method according to the invention in the form of selective synthetic crystallization is particularly to be seen in the fact that, by varying the precursor material with the same method, materials for semiconductor technology as well as mechanically and thermally extremely resistant materials are accessible.

Particularly good results are obtained in this connection when the process is an inkjet printing process, i.e. H. the precursor material mixture, in particular the precursor solution or dispersion, is applied to the substrate by means of inkjet printing. The use of inkjet printing processes allows, in particular, a high-resolution and locally sharply delimited application of the precursor material while at the same time using little material, so that even filigree structures are accessible for semiconductor applications. In particular, it is also preferred if so-called drop-on-demand processes or printers are used, only the drops of liquid being generated which are actually actually applied to the substrate.

• 1 schematisch eine perspektivische Darstellung einer Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens zur Herstellung einer SiC-haltigen Struktur, insbesondere aus einer Fest-in-fest-Precursormaterialmischung, vorzugsweise einem Precursorpulver, im Ausgangszustand;
• 2 schematisch eine Querschnittsdarstellung einer Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens zur Herstellung einer SiC-haltigen Struktur, insbesondere aus einer Fest-in-fest-Precursormaterialmischung, vorzugsweise einem Precursorpulver, im Ausgangszustand;
• 3 schematisch eine Querschnittsdarstellung einer Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens zur Herstellung einer SiC-haltigen Struktur, insbesondere aus einer Fest-in-fest-Precursormaterialmischung, vorzugsweise einem Precursorpulver, im Arbeitszustand;
• 4 schematisch eine weitere Querschnittsdarstellung einer Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens zur Herstellung einer SiC-haltigen Struktur, insbesondere aus einer Fest-in-fest-Precursormaterialmischung, vorzugsweise einem Precursorpulver, im Arbeitszustand;
• 5 schematisch eine wiederum weitere Querschnittsdarstellung einer Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens zur Herstellung einer SiC-haltigen Struktur, insbesondere aus einer Fest-in-fest-Precursormaterialmischung, vorzugsweise einem Precursorpulver, im Arbeitszustand;
• 6 schematisch eine Darstellung einer Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens zur Herstellung einer SiC-haltigen Struktur, insbesondere aus einer Fest-in-fest-Precursormaterialmischung, vorzugsweise einem Precursorpulver, in der Draufsicht;
• 7 schematisch eine perspektivische Darstellung einer alternativen Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens zur Herstellung einer SiC-haltigen Struktur, insbesondere aus einer Fest-in-flüssig- bzw. Flüssig-in-flüssig-Precursormaterialmischung, vorzugsweise einer Precursordispersion, im Ausgangszustand;
• 8 schematisch eine Querschnittsdarstellung einer alternativen Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens zur Herstellung einer SiC-haltigen Struktur, insbesondere aus einer Fest-in-flüssig- bzw. Flüssig-in-flüssig-Precursormaterialmischung, vorzugsweise einer Precursordispersion, im Ausgangszustand;
• 9 schematisch eine Querschnittsdarstellung einer alternativen Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens zur Herstellung einer SiC-haltigen Struktur, insbesondere aus einer Fest-in-flüssig- bzw. Flüssig-in-flüssig-Precursormaterialmischung, vorzugsweise einer Precursordispersion, im Arbeitszustand;
• 10 schematisch eine weitere Querschnittsdarstellung einer alternativen Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens zur Herstellung einer SiC-haltigen Struktur, insbesondere aus einer Fest-in-flüssig- bzw. Flüssig-in-flüssig-Precursormaterialmischung, vorzugsweise einer Precursordispersion, im Arbeitszustand;
• 11 schematisch eine wiederum weitere Querschnittsdarstellung einer alternativen Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens zur Herstellung einer SiC-haltigen Struktur, insbesondere aus einer Fest-in-flüssig- bzw. Flüssig-in-flüssig-Precursormaterialmischung, vorzugsweise einer Precursordispersion, im Arbeitszustand;
• 12 schematisch eine Darstellung einer alternativen Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens zur Herstellung einer SiC-haltigen Struktur, insbesondere aus einer Fest-in-flüssig- bzw. Flüssig-in-flüssig-Precursormaterialmischung, vorzugsweise einer Precursordispersion, in der Draufsicht.

It shows the figure representations according to

• 1 schematically a perspective representation of a device for carrying out the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-solid precursor material mixture, preferably a precursor powder, in the initial state;
• 2 schematically a cross-sectional representation of a device for performing the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-solid precursor material mixture, preferably a precursor powder, in the initial state;
• 3rd schematically a cross-sectional representation of a device for performing the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-solid Precursor material mixture, preferably a precursor powder, in the working state;
• 4th schematically, a further cross-sectional representation of a device for carrying out the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-solid precursor material mixture, preferably a precursor powder, in the working state;
• 5 schematically yet another cross-sectional representation of a device for carrying out the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-solid precursor material mixture, preferably a precursor powder, in the working state;
• 6th a schematic representation of a device for carrying out the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-solid precursor material mixture, preferably a precursor powder, in plan view;
• 7th schematically a perspective illustration of an alternative device for carrying out the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-liquid or liquid-in-liquid precursor material mixture, preferably a precursor dispersion, in the initial state;
• 8th schematically a cross-sectional representation of an alternative device for performing the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-liquid or liquid-in-liquid precursor material mixture, preferably a precursor dispersion, in the initial state;
• 9 schematically a cross-sectional representation of an alternative device for performing the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-liquid or liquid-in-liquid precursor material mixture, preferably a precursor dispersion, in the working state;
• 10 schematically a further cross-sectional representation of an alternative device for carrying out the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-liquid or liquid-in-liquid precursor material mixture, preferably a precursor dispersion, in the working state;
• 11 schematically yet another cross-sectional representation of an alternative device for carrying out the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-liquid or liquid-in-liquid precursor material mixture, preferably a precursor dispersion, in the working state;
• 12th a schematic representation of an alternative device for performing the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-liquid or liquid-in-liquid precursor material mixture, preferably a precursor dispersion, in plan view.

Another object of the present invention - according to a second aspect of the present invention - is a use of a radiation source, in particular a laser, preferably a diode laser, preferably a grouping of several diode lasers, more preferably a laser array, very particularly preferably a VCSEL laser array, for the production of SiC-containing structures, in particular by the method described above.

With the use according to the invention of a radiation source, in particular a laser, which is preferably formed from a grouping or combination of individual radiation sources, in particular individual emitters, the speed at which an SiC-containing structure can be manufactured can be significantly increased . It is a central advantage of the radiation source used according to the invention that the individual radiation sources can be controlled individually and at the same time coordinated with one another in concert.

Using the radiation source described, the present method overcomes a significant disadvantage of common laser-based methods, in which high-energy individual lasers are usually used that can only scan a predetermined area linearly over time. The production speed for these processes is therefore severely limited, so that the production processes are altogether too lengthy to be of interest for industrial application.

In contrast, the use according to the invention of a radiation source, which is preferably designed as a grouping of several diode lasers, ie preferably as a laser array, very particularly preferably as a VCSEL laser array, allows those individual areas which are to define the SiC-containing structure in their entirety to be simultaneously next to one another specifically set times can be selectively irradiated over a specific duration. In this way, the SiC precursor material can be used within a much shorter time per layer or layer the previously defined areas are converted to SiC-containing material.

In detail, it can be emphasized for the method according to the invention that by means of the use according to the invention of a special multi-part or multi-part radiation source, an SiC precursor material layer or layer, which - computationally, ie already during CAD modeling - is divided into a large number of pixel-like individual areas is broken down, can now be converted to the SiC-containing material in a location-selective manner and in accordance with a specific time setting in several of these pixel-like individual areas simultaneously. This is not possible with the previously known methods for generative SiC production.

For further details on the use according to the invention, reference can be made to the above statements on the method according to the invention.

Another object of the present invention - according to a third aspect of the present invention - is an SiC-containing structure, obtainable by the method described above.

In particular, the silicon carbide-containing structure can be a two-dimensional structure, for example a conductor track, or also a three-dimensional structure, ie. H. a three-dimensional object or body.

For further details on this aspect of the invention, reference can be made to the above statements on the method according to the invention, which apply accordingly with regard to the silicon carbide-containing structure.

The subject matter of the present invention is explained below on the basis of preferred embodiments in a non-limiting manner by means of the representations of the figures.

It shows 1 a perspective view of a generative manufacturing device 1 for carrying out the method according to the invention for the production of SiC-containing structures, in particular from a solid-in-solid precursor material mixture, preferably a precursor powder, in the initial state, ie before the start of the production method according to the invention.

The generative manufacturing device is preferred 1 for performing the method according to the invention, that is, based on devices for performing powder bed methods, in particular devices for performing selective laser sintering (SLS).

The generative manufacturing device 1 to carry out the method according to the invention preferably has a pressure bed 2 for providing the precursor material, a solid-in-solid precursor material mixture, in particular a precursor powder, preferably a precursor granulate, preferably being used for the particular embodiment of the present invention in this regard. The print bed 2 is preferably designed in particular at least substantially flat and / or planar and preferably has a construction platform 3rd as well as a print area 4th on.

The print area 4th serves in particular as an area in which the method according to the invention for producing SiC-containing structures can be carried out and preferably comprises a smaller area than the construction platform 3rd and is also preferably centered on the build platform 3rd arranged.

Furthermore, the build platform is 3rd preferably movable in the vertical direction, in particular lowerable, and according to a further preferred embodiment of the generative manufacturing device 1 a boundary at their surface edges 5 on, in particular being the limitation 5 the build platform 3rd framed. Weeping is the limit 5 preferably designed so that they are in the initial state with the surface of the building platform 3rd , especially flush.

Next to the print bed 2 instructs the manufacturing device 1 preferably an application device 6th for the, in particular powdery, precursor material 7th on the print bed 2 on. According to a preferred embodiment, it can be provided that the application device 6th to equalize the precursor material 7th at least essentially cylindrical, in particular at least essentially cylindrical, preferably in the form of an applicator roller 6a , is trained. Alternatively, it can be done in the context of a further, not shown, embodiment of the manufacturing device 1 be provided that the application device 6th is in the form of a doctor blade, in particular having a rubber lip.

In general, it has preferably proven useful if the application device 6th in the horizontal direction across the print bed 2 is movable.

It is also preferred if the application device 6th is arranged so that it is the precursor material 7th in layers 7a , in particular layers, of the precursor material can be applied. In the context of the present preferred embodiment of the method according to the invention, the precursor material can be used as a solid-in-solid precursor material mixture, in particular as a Precursor powder or precursor granulate is used, it can be provided that the layers 7a , in particular layers, have a layer thickness in the range from 1 to 1,000 μm, in particular 2 to 500 μm, preferably 5 to 250 μm, preferably 10 to 180 μm, particularly preferably 20 to 150 μm, very particularly preferably 20 to 100 μm. The application device is for this purpose 6th preferably immediately above, in particular above and at least essentially flush with the boundary 5 of the print bed 2 , arranged.

At the same time, it has then proven that the construction platform 3rd can be lowered, specifically preferably - in correlation with the method according to the invention - by an amount that corresponds to the thicknesses of the layers 7a , in particular layers of the precursor material 7th , in particular the precursor powder, preferably the precursor granulate. That is, the build platform 3rd per order of one layer 7a can be lowered by an amount of 1 to 1,000 μm, in particular 2 to 500 μm, preferably 5 to 250 μm, preferably 10 to 180 μm, particularly preferably 20 to 150 μm, very particularly preferably 20 to 100 μm, in particular if the invention Process is carried out as a solid process.

The limit then protrudes correspondingly 5 the generative manufacturing device 1 by the amount of strength of the location 7a , especially layer, over the build platform 3rd out.

Next to the print bed 2 and the application device 6th has the generative manufacturing device 1 according to the present preferred embodiment furthermore a radiation source 8th - also irradiation facility 8th called - on, this being above the print bed 2 is arranged.

The radiation source 8th can be designed so that these a plurality of individual radiators 10 having. In particular, the radiation source 8th more than 20, preferably more than 50, preferably more than 100 individual radiators 10 , in particular single emitters.

It is preferably also provided that the radiation source 8th a laser, in particular a diode laser, preferably a grouping of several diode lasers, preferably a laser array, more preferably a VCSEL laser array.

According to a preferred embodiment, the radiation source is 8th thus in the form of a grouping of several individual radiators 10 , in particular diode lasers, arranged, the individual radiators 10 , in particular the individual diode lasers or laser diodes, are combined or connected electrically and / or optically, in particular electrically and optically. This advantageously allows in particular coordinated or concerted control of the individual radiators 10 so that both an isolated single radiator 10 as well as a plurality of, in particular isolated or adjacent, individual radiators 10 can be controlled, ie switched on and off, at a given, predetermined point in time over a specific period of time.

The grouping of several individual radiators 10 , in particular diode lasers, can in particular also be used as (laser) bars or laser bars on a strip-shaped chip, having the individual radiators 10 , in particular the diode laser, be formed. The single emitters 10 The diode lasers in a laser bar, in particular, are usually operated electrically in parallel and mounted on a heat sink.

The laser bars show the individual emitters 10 preferably both in the x and in the y direction within a plane z. The z-plane in which the individual radiators 10 are arranged in a laser bar, is preferably parallel to the surface of the print bed 2 oriented, so that an in particular at least substantially uniform distance between the individual radiators 10 and the print bed 2 or a layer applied to it 7a of the precursor material 7th consists. In an advantageous manner, this provides a uniformly intensive energy input in all areas of the print bed 2 safe and also allows a reliable, locally specific focusing of the irradiation. In this way, temperatures such as are necessary for the formation of silicon carbide or SiC-containing material can be generated and maintained precisely in a narrowly limited range.

In addition, it can preferably be provided that the individual radiators 10 in the radiation source 8th , in particular the laser bar, are each arranged in rows in the x- and y-correct manner, so that a particularly regular arrangement of the individual emitters 10 results, which preferably in a space-saving manner the numerically practically feasible maximum possible arrangement of individual radiators 10 on the irradiation facility 8th , especially the laser bar.

Furthermore, it can be provided that two or more laser bars are combined with one another, so that the radiation source 8th according to a particularly preferred embodiment of the generative manufacturing device 1 than a laser array 8a is trained.

In the context of a further preferred embodiment of the generative manufacturing device 1 it can be provided that the radiation source 8th across the entire width of the print area 4th , in which the inventive Manufacturing process can be carried out is arranged. That is, the radiation source 8th , especially the laser bar, preferably the laser array 8a , corresponds in particular in one dimension at least substantially to the expansion of the print bed 2 , for example in the x or y direction. Furthermore, it has proven to be advantageous if the radiation source 8th is designed so that this is in the horizontal direction over the print bed 2 is movable. Thus, in the course of the generative manufacturing process, it is already possible to scan with one pass, ie by moving over or moving over the print bed once 2 by the radiation source 8th , in particular the laser bar or preferably the laser array 8a , one layer of the SiC-containing structure can be produced in each case. It is also preferred here if the radiation source 8th is arranged at such a height above the print bed that the irradiation of the precursor material 7th , especially the locations 7a of the precursor material, essentially limited in terms of location and / or time, in particular limited in terms of location and time, preferably time-specifically limited in a location-selective manner, so that the energy input can be carried out in particular essentially precisely and avoiding a local deflection of the laser radiation 9 takes place. The above-described, preferably arrangement of the individual radiators also contributes to this 10 in the radiation source 8th , in particular the laser bar, preferably the laser array 8a , at which in a plane z, which is parallel to the surface of the print bed 2 oriented, lies.

In the context of an alternative and preferred embodiment of the manufacturing device, but not shown in the figure representation 1 however, it can also be provided that the radiation source 8th , especially the laser array 8a , is designed so that it has a compact, area-optimized shape and a reduced number of individual radiators 10 has, which can be particularly suitable for an application of the method according to the invention on an extrusion basis.

In the context of yet another preferred alternative embodiment of the present invention, which, however, is not shown, it can again likewise be provided that the radiation source 8th a combination of at least one means for generating electromagnetic radiation, in particular at least one radiator, with at least one optical waveguide, in particular glass fiber cable, and / or at least one lens. The radiation source particularly preferably has 8th a combination of a plurality of means for generating electromagnetic radiation, in particular radiators, with a plurality of optical waveguides, in particular glass fiber cables, and a plurality of lenses.

According to this alternative embodiment of the manufacturing device 1 it is then possible that at least part of the radiation source 8th , namely the means for generating electromagnetic radiation, in particular the radiators, separately, ie from the print bed 2 or pressure area 4th are spatially independent, and in particular are arranged in a fixed manner. The combination of the means for generating electromagnetic radiation, ie in particular the single-beam laser or also the grouping of individual lasers, in particular diode lasers, with optical waveguides enables the laser beams 9 to a movable exposure means having the plurality of lenses. The lens or lenses in turn allow the laser beams to be deflected or focused 9 So that, as a result, also according to this embodiment, the energy input is limited in terms of location and / or time, in particular is limited in terms of location and time, preferably limited in a location-selective manner and in a time-specific manner.

An advantage of this alternative embodiment of the manufacturing device 1 consists in the fact that the laser beams are focussed, in particular, pixel-by-pixel 9 is possible without adding the radiation source 8th , in particular the grouping of individual lasers, in particular diode lasers, must be arranged in the form of these pixels, ie the distance between the individual lasers can be greater than the area of a pixel. In addition, this arrangement also enables, in particular, an optimized weight distribution of the radiation source 8th can be achieved.

According to a particularly preferred embodiment of the generative manufacturing device 1 it can also be provided that the radiation source 8th , especially the single emitters 10 Have powers of less than 7 W, in particular less than 5 W, preferably less than 4 W, preferably less than 3 W, or with an effective range of significantly less than 500 μm, in particular less than 300 μm, preferably less than 200 µm, preferably less than 150 µm, emit.

In the initial state of the manufacturing device 1 are the application device 6th for the precursor powder and the irradiation device or radiation source 8th preferably orthogonal to one another and each at an edge of the print bed 2 , which in particular by the limitation 5 is formed, positioned.

The 2 shows schematically a cross-sectional representation of the generative manufacturing device 1 for carrying out the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-solid Precursor material mixture, preferably a precursor powder, in the initial state.

In addition to the features already mentioned, the production device 1 - According to a further preferred embodiment of the manufacturing device 1 - a storage facility 12th for the, in particular powdery, precursor material 7th on the side next to the print bed 2 is arranged.

Here is the storage facility 12th for the precursor material 7th designed so that they - analogous to the print bed 2 - In particular a substantially flat and / or planar and preferably movable, in particular liftable, base surface in the vertical direction 12a having. In addition, the storage facility 12th according to a further, preferred embodiment, likewise a delimitation at its surface edges 5 , in particular a storage facility 12th framing boundary 5 , on. In the context of this preferred embodiment, the storage device contains 12th the precursor material at the beginning of the manufacturing process 7th .

For this special, preferred embodiment of the manufacturing device 1 it is also provided that the application device 6th , especially in the form of the application roller 6a or in the form of the doctor blade, also via the storage device 12th is movable in the horizontal direction, in particular over the print bed 2 and the storage facility 12th is movable in the horizontal direction.

The 3rd shows schematically a cross-sectional representation of the manufacturing device 1 when carrying out the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-solid precursor material mixture, preferably a precursor powder, according to process step (a) described above, in the course of this the precursor material 7th , containing at least one silicon source and at least one carbon source, in the form of a layer 7a , in particular a layer, is provided.

In the context of this method step, the construction platform 3rd by the amount of strength of the location 7a , in particular layer, lowered and the base area 12a the storage facility 12th for the precursor powder, increased by an amount that is sufficient for the material of the precursor material 7th made available so that the applicator 6th , especially the order roller 6a or the squeegee on the build platform 3rd a location 7a , in particular layer, with a thickness in the aforementioned range can be applied. The application device 6th , especially the order roller 6a or the doctor blade, starting from the storage device 12th over the print bed 2 moves, so that in the course of this the precursor material 7th is distributed.

It shows the 4th a schematic cross-sectional view of the generative manufacturing device 1 when carrying out the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-solid precursor material mixture, preferably a precursor powder, according to step (b), in the course of this by a repeated and / or continuous input of energy by at least one radiation source at least in some areas the precursor material 7th to a SiC-containing material, in particular successively a SiC-containing structure 13th , is implemented.

The radiation source is used for this 8th horizontally across the print bed 2 emotional. In the course of this, the energy is introduced, in particular by electromagnetic radiation or preferably by laser radiation 9 , into the precursor material 7th through the corresponding individual radiators 10 , especially the single emitters. Here are the individual radiators 10 in particular individually controllable so that the energy input can be limited in terms of location and / or time, in particular limited in terms of location and time, preferably time-specifically limited in a location-selective manner. It is furthermore preferably provided that the energy input is a temperature increase, in particular a locally and / or temporally limited temperature increase, preferably a spatially and temporally limited temperature increase, preferably a location-selectively time-specifically limited temperature increase, in the precursor material 7th causes. It can thus be achieved that the implementation of the precursor material 7th to the SiC-containing structure 13th takes place in a predefinable and, in particular, location and time-resolved manner.

It shows the 5 a schematic cross-sectional view of the generative manufacturing device 1 when carrying out the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-solid precursor material mixture, preferably a precursor powder, in accordance with the repetition of method steps (a) and (b), which takes place so often that the predefined SiC -containing structure 13th is obtained.

For further details on the method steps, reference can be made to the preceding figures and descriptions.

It shows the 6th a schematic representation of the manufacturing device 1 for carrying out the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-solid precursor material mixture, preferably a precursor powder, in the Top view. After completion of the SiC-containing structure 13th is the manufacturing device 1 arranged analogously to the initial state. Within the printing area 4th , in which the production method according to the invention for producing the SiC-containing structure 13th can be executed, the finished three-dimensional SiC-containing structure is located 13th , but still inside the print bed 2 surrounded by unreacted precursor material 7th .

Following the production process according to the invention, a final process step (c) can therefore follow in a further preferred embodiment of the present invention, in the context of which the SiC-containing structure obtained 13th is cleaned and / or reworked.

It shows the 7th schematically a perspective representation of the generative manufacturing device 1 according to an alternative preferred embodiment of the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-liquid or liquid-in-liquid precursor material mixture, preferably a precursor dispersion 16 , in the context of a liquid printing process, in particular an inkjet process, in the initial state.

The manufacturing device 1 is essentially analogous to the manufacturing device according to FIG 1 formed, with the difference that the manufacturing process is carried out as a liquid printing process, so that instead of the application device 6th for the precursor powder, an alternative application device 14th for the precursor dispersion 16 , having, in particular a plurality of, application nozzles 15th , in connection with a storage facility 12th for the precursor dispersion, is provided.

Furthermore, it can preferably be provided that the application device 14th in combination with the radiation source 8th is trained. In addition, the remarks on the radiation source 8th according to the preceding 1 to 6th as it were to the present special configuration of the manufacturing device 1 are transferred, in particular also to the combination of application device 14th and radiation source 8th .

In addition, the order setup is 14th preferably designed so that it is used for applying the, in particular liquid, precursor material 7th on the print bed 2 , especially the printing area 4th , several, preferably a plurality of, application nozzles 15th has, so for example at least 10, preferably at least 20.

Preferably the application nozzles are 15th individually controllable and at the same time enable the application of the, in particular liquid, precursor material 7th preferably by uniform, fine dripping, in particular sprinkling, spraying, drizzling on and / or wetting.

It has also proven useful if the application device 14th preferably at such a height above the print bed 2 is arranged that the application of the precursor material 7th can be done essentially in a precisely positional manner and avoiding local distraction.

It can within the scope of an even more preferred embodiment of the manufacturing device, not shown 1 be provided that the application device 14th for the precursor dispersion 16 is designed so that selectively different precursor materials, in particular in different areas or levels of the print bed 2 , can be applied. This allows in particular the production of conductor tracks or generally of semiconductor electronics from and in SiC-containing materials.

For this purpose, it is preferred for this particular design if the application nozzles 15th are designed so that different precursor dispersions 16 , in particular different precursor sols or components for the production of precursor sols, separately and specifically, in particular in different areas or levels of the print bed 2 or layers already produced thereon, in particular layers of SiC-containing material, can be applied.

For this it has proven to be advantageous if the application nozzles 15th Via separate lines, in particular to the, preferably several, storage devices 12th the different precursor dispersions 16 , and can be controlled individually. It is very particularly preferred in this context if the metering and the location-selective or time-specific application of the different precursor dispersions are coordinated and controlled via a control device. In this way, in the context of this preferred embodiment of the method according to the invention, it is particularly possible to carry out the method according to the invention as a multi-material printing method, in particular based on the inkjet method.

The 8th shows schematically a cross-sectional representation of the alternative preferred embodiment of the generative manufacturing device 1 for carrying out the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-liquid or liquid-in liquid precursor material mixture, preferably a precursor dispersion, in the initial state.

It shows the 9 schematically a cross-sectional view of the alternative preferred embodiment of the manufacturing device 1 for performing the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-liquid or liquid-in-liquid precursor material mixture, preferably a precursor dispersion, in the working state, in particular when performing the method according to the invention according to the method step described above (a), in the course of which the precursor material 7th , in particular the liquid-in-liquid or solid-in-liquid precursor material mixture, containing at least one silicon source and at least one carbon source, in the form of a layer 7a , in particular a layer, is provided.

It is the preferred embodiment of the manufacturing device for this alternative 1 in order to carry out the production method according to the invention, provision is made in particular that the position 7a is applied with a layer thickness in the range from 0.1 to 250 µm, in particular 0.2 to 100 µm, preferably 0.5 to 50 µm, preferably 1 to 25 µm. In this context, it has further proven itself when the build platform 3rd by a corresponding amount of the layer thickness of the layer 7a , especially layer, is lowered. With regard to the design of the order, reference can be made to the relevant statements according to the preceding figures.

It shows the 10 schematically a cross-sectional view of the alternative preferred embodiment of the manufacturing device 1 for carrying out the process according to the invention for producing a SiC-containing structure, in particular from a solid-in-liquid or liquid-in-liquid precursor material mixture, preferably a precursor dispersion, when carrying out the process according to the invention according to step (b), in In the course of this, through a repeated and / or continuous input of energy from at least one radiation source 8th the precursor material 7th at least in some areas to a SiC-containing material, in particular successively to a SiC-containing structure 13th , is implemented. Refer to the explanations relating to process step (b) under 4th can be referenced here analogously.

It shows the 11 again a schematic cross-sectional illustration of the alternative embodiment of the manufacturing device 1 for carrying out the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-liquid or liquid-in-liquid precursor material mixture, preferably a precursor dispersion, in the working state in which process steps (a) and (b ) are repeated so often that a SiC-containing structure 13th is obtained. On the relevant statements on 5 can be referenced here analogously.

Last but not least, the shows 12th a schematic representation of the alternative embodiment of the manufacturing device 1 for carrying out the method according to the invention for producing a SiC-containing structure, in particular from a solid-in-liquid or liquid-in-liquid precursor material mixture, preferably a precursor dispersion, as a top view. After completion of the SiC-containing structure 13th is the manufacturing device 1 arranged analogously to their initial state. To the relevant further statements in accordance with 6th can be referenced here analogously.

List of reference symbols

1

generative manufacturing device

2

Print bed

3

Build platform

4th

Pressure area

5

Limitation

6th

Applicator for the precursor powder

6a

Order roller

7th

Precursor material

7a

location

8th

Radiation source

8a

Laser array

9

Laser radiation

10

Single emitter

11

Storage device for precursor dispersion

12th

Storage device for precursor powder

12a

Base area of the storage facility

13th

SiC-containing structure

14th

Application device for the precursor dispersion

15th

Application nozzles

16

Precursor dispersion

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102015100062 A1 [0016]
• DE 102015105085 A1 [0017, 0018, 0019, 0020]
• DE 102017110362 A1 [0017, 0022, 0023, 0120, 0194, 0195]
• DE 102017110361 A1 [0017, 0023, 0122, 0143, 0194, 0196]
• DE 102019121062 [0017, 0020, 0021, 0128]
• WO 2018/206645 A1 [0022, 0023, 0120, 0194, 0195]
• DE 102018128434 [0023]
• WO 2018/206643 A1 [0023, 0122, 0143, 0194, 0196]
• DE 102018127877 [0121]

Claims (18)

Process for the production of SiC-containing structures, characterized in that a precursor material containing at least one silicon source and at least one carbon source is converted into a SiC-containing material through a repeated and / or continuous input of energy by at least one radiation source. Procedure according to Claim 1 , characterized in that the energy input takes place by electromagnetic radiation, in particular laser beams. Procedure according to Claim 1 or 2 , characterized in that the energy input is limited in terms of location and / or time, in particular limited in terms of location and time, preferably time-specifically limited in a location-selective manner. Method according to one of the Claims 1 to 3rd , characterized in that the energy input has an effective range of less than 750 µm, in particular less than 500 µm, preferably less than 300 µm, preferably less than 150 µm. Method according to one of the Claims 1 to 4th , characterized in that the energy input causes a temperature increase, in particular a locally and / or temporally limited temperature increase, preferably a spatially and temporally limited temperature increase, preferably a location-selectively time-specifically limited temperature increase. Procedure according to Claim 5 , characterized in that the energy input causes a temperature rise to temperatures in the range of more than 1000 ° C, in particular more than 1,400 ° C, preferably more than 1,600 ° C. Method according to one of the Claims 1 to 6th , characterized in that the radiation source has a plurality of, in particular more than 20, preferably more than 50, preferably more than 100, individual radiators, in particular individual emitters, in particular is formed therefrom. Method according to one of the Claims 1 to 7th , characterized in that the radiation source is a laser, in particular a diode laser, preferably a grouping of several diode lasers, preferably a laser array, more preferably a VCSEL laser array. Method according to one of the Claims 7 or 8th , characterized in that the radiation source is designed as a laser bar and / or a combination of at least one means for generating electromagnetic radiation with at least one optical waveguide, in particular fiber optic cable, and / or at least one lens, in particular a combination of a plurality of means for generating electromagnetic radiation Has radiation with a plurality of optical waveguides, in particular glass fiber cables, and / or a plurality of lenses. Method according to one of the Claims 1 to 9 , characterized in that the radiation source, in particular the individual radiators, have powers of less than 7 W, in particular less than 5 W, preferably less than 4 W, preferably less than 3 W. Method according to one of the Claims 1 to 10 , characterized in that the radiation source, in particular the individual radiators, emit radiation with an effective range of less than 500 µm, in particular less than 300 µm, preferably less than 200 µm, preferably less than 150 µm. Method according to one of the preceding claims, characterized in that the precursor material from the group of solid-in-solid precursor material mixtures, solid-in-liquid precursor material mixtures, liquid-in-liquid precursor material mixtures, in particular from precursor powders, precursor dispersions, preferably from precursor granules , Precusorsolen, is selected. Method according to one of the preceding claims, characterized in that the silicon source is selected from the group of silanes, silane hydrolysates, silicates, silica sols, orthosilicic acids, water glasses, elemental silicon and their mixtures, in particular silanes, silane hydrolysates, elemental silicon and their Mixtures. Method according to one of the preceding claims, characterized in that the carbon source is selected from the group of carbohydrates, in particular glucose, fructose, invert sugar, sucrose, maltose, lactose, amylose, amylopectin, starch, starch derivatives, or from the group of organic Polymers, in particular phenol-formaldehyde resin and resorcinol-formaldehyde resin, and mixtures thereof. Method according to one of the preceding claims, characterized in that in a final method step (c) the SiC-containing structure obtained is cleaned and / or reworked. Method according to one of the preceding claims, characterized in that the manufacturing method is a generative manufacturing method, in particular a printing bed-based generative manufacturing method. Use of a radiation source, in particular a laser, preferably a diode laser, preferably a grouping of several diode lasers, more preferably a laser array, very particularly preferably a VCSEL laser array, for the production of SiC-containing structures, in particular by the method according to one of the Claims 1 to 16 . SiC-containing structure, obtainable by the process according to one of the Claims 1 to 16 .

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