Additive manufacturing method involving modification of sublayers

Abstract

The invention relates to an additive manufacturing method comprising the following steps: - additively applying a material layer (1), and - modifying a part of the applied material layer (1) in terms of one property such that a sublayer (3) in the material layer (1) is structured, wherein the sublayer (3) differs from the rest of the material layer at least in terms of the modified property. The invention also relates to a correspondingly manufactured component and to a suitable manufacturing apparatus.

Description

[0001] Additive manufacturing process with modification of sublayers

[0002] The present application relates to an additive manufacturing process during which partial layers in components are modified.

[0003] Numerous additive manufacturing processes are known in the state of the art. Additive manufacturing enables the structured construction of components, even with unusual shapes, without material loss through subsequent processing. The shaping of the component occurs during its production.

[0004] However, the current state of the art limits the additive manufacturing of components with certain components, making it difficult or even impossible. For example, electronic or catalytically active components are still mounted separately in or on the component and cannot be printed during the additive manufacturing process.

[0005] An exemplary method for applying and modifying electrically conductive components, in particular on 2D substrates, is the application of a substrate material and its subsequent modification by means of a laser-induced graphene process, which is known, for example, from the documents US 2020 / 0 112 026 Al, US 2020 / 0 348 121 Al, CN 111 879 341 A or WO 2018 085 789 Al.

[0006] The electrical conductivity of the modified LIG material can be further increased in post-treatment steps, as shown in publications CN 109 440 145 A, US 2018 / 0 199 441 A1 and WO 2020 197 606 A2. The publications US 2021 / 0 395 420 A1 and WO 2017 051 182

[0007] Al continue to reveal state-of-the-art high-temperature resistant materials.

[0008] CN 114322741 A provides an example of a manufacturing process for a ceramic film sensor. A metal component is provided as a substrate, and a precursor layer for a ceramic insulating film is applied, for example, by screen printing. However, this process does not allow for the structuring of a partial layer in a pre-printed font.

[0009] DE 102019101268 A1 discloses a method for producing and modifying objects containing silicon carbide.

[0010] WO 2017 / 176251 A1 shows a printing process in which a photosensitive additive is distributed on a section of a previously applied polymer layer using a liquid ink as a vehicle.

[0011] US 2018 / 0129002 Al discloses various possible post-treatment steps for the surface treatment of additively manufactured electrical components.

[0012] US 9,827,713 Bl and WO 2020 / 236455 Al finally disclose special apparatus for 3D printing, which have several processing stations in which the individual steps of the printing process are carried out.

[0013] US 9,827,713 Bl shows a robot arm that immerses a substrate in different resins at several stations in order to form the different layers of a component.

[0014] In WO 2020 / 236455 A1, several plates are fused one after the other to form layers of a component. One aim of the present application is to provide a method, a component, and an apparatus that overcome the disadvantages of the prior art.

[0015] The present invention relates to an additive manufacturing process comprising several steps.

[0016] In a first step, a layer of material is additively applied. The layer can be applied, for example, to a dedicated build plate or to a previously additively applied layer. The layer can comprise any material suitable for additive manufacturing or 3D printing.

[0017] In a further step, at least a portion of the previously applied material layer is modified in one property, so that a sublayer in the material layer is structured. A portion of the material layer can be referred to here as a sublayer. The sublayer differs from the remaining material layer, outside the modified portion of the layer, in at least one material property. In one embodiment, the entire material layer is modified.

[0018] During modification, a chemical, physical, morphological and / or structural property of the material layer can be changed, among other things. In various embodiments of the invention, the electrical conductivity, porosity or grain size of the material layer is changed, or an organic material is carbonized into an inorganic carbon material. For example, a portion of the applied material layer is modified in such a way that the electrical conductivity in that portion of the layer is changed, thus structuring a partial layer whose electrical conductivity differs from the conductivity of the remaining material layer.

[0019] During modification, several properties of the material layer can be altered through a modification step. For example, the sublayer structured after modification can differ from the remaining material layer in terms of its electrical conductivity, porosity, and grain size.

[0020] Using the described process, a layered structure with various desired properties can be created without printing separate layers. Furthermore, the properties of the printed material layer can be adjusted during the additive manufacturing process, eliminating the need for any post-processing steps.

[0021] The targeted modification of properties of previously additively manufactured layers also enables the additive manufacturing of components with properties that cannot be produced using a conventional additive manufacturing process. These properties include, in particular, the aforementioned properties of electrical conductivity, grain size, porosity, and other comparable material properties. After the material layer has been applied and modified, a further material layer can be applied in a subsequent process step and again modified in such a way that at least one material property in that part of the layer is changed, thus structuring a partial layer which differs in one material property from the conductivity of the remaining material layer.

[0022] Alternatively, a material layer can be applied in which no sublayer is modified.

[0023] In particular, the sublayer can be structured in such a way that it matches the sublayer in the first material layer and the two sublayers form, for example, a coherent layer with homogeneous properties.

[0024] In particular, in one embodiment, the same electrical conductivity is set in the partial layer and the further partial layer. Thus, an electrically conductive layer, for example an internal electrode, can be structured in an electrically non-conductive material.

[0025] In one embodiment, the material layer and the further material layer are applied directly to one another or directly adjacent to one another. In other embodiments, the material layers can be applied both adjacent to one another and one upon the other.

[0026] The material layer can consist of different materials, in particular of a structural material and a modifiable material.

[0027] The different materials are applied in several steps of the printing process. A structural material may not be suitable for the modification step described, but it provides a desired structure for the component to be manufactured.

[0028] A modifiable material is suitable for modification during the modification step. Thus, a portion of the modifiable material can be modified to create a structure with desired properties.

[0029] The modifiable material should preferably be a high-temperature-resistant material that is particularly suitable for 3D printing using bath-based photopolymerization, such as the plastic classes ThermoBlast or DL-400.

[0030] A material can be considered "high-temperature resistant" if it can withstand an ambient temperature of at least 300 °C. Accordingly, the melting or

[0031] Decomposition point of a high temperature resistant material is above 300 °C and the structure of the high temperature resistant material is not changed at temperatures up to 300 °C.

[0032] These can include, for example, active layers or internal electrodes within the material layers. The remaining material layer, which is not modified, continues to contribute to the overall structure of the component.

[0033] In one embodiment, the material layer or the further material layer comprises ceramic materials.

[0034] In a further embodiment, the material layer or the further material layer comprises metals. The layer material can then be modified by sintering in a portion of the applied material layer, thus structuring the partial layer. The partial layer can, for example, comprise or consist of a metal or ceramic material.

[0035] Targeted, spatially resolved sintering enables the structuring of specific sublayers with desired properties. For example, the ceramic material can be modified during sintering so that conductive metallic sublayers form within the ceramic layer. An organic material with metallic or ceramic inclusions can, for example, be modified so that organic components are removed and metallic or ceramic sublayers are formed that predominantly comprise a metal or ceramic or consist of such a material.

[0036] Furthermore, the porosity of the sublayer is modified by sintering. In particular, structures with larger pores can be formed. By modifying the pores, the material's suitability as a catalyst, carrier substance, or filter unit can be adjusted, for example.

[0037] In a further embodiment, the material layer or the further material layer comprises an organic material or consists of organic material. Ceramic and / or metal materials, which can be modified, for example, as described above, are preferably additionally embedded in the organic materials, in particular plastics. Preferably, the material layer or the further material layer comprises plastics or consists of plastics.

[0038] In addition, natural materials such as cellulose-based materials and modified natural materials such as rubber, viscose and cellophane can also be used as organic materials.

[0039] Various plastics can be used. Homogeneous material layers made from a single, uniform base material are particularly preferable. Possible materials include PI, PEI, PE, PP, etc.

[0040] Blends, i.e., non-chemically cross-linked mixtures, of two pure plastic materials or chemically cross-linked copolymers such as ABS are also conceivable. In other embodiments, the materials of the material layers also include composite materials such as GSK or PCB, or polymer materials with fillers such as embedded ceramic or metal particles.

[0041] In the plastic material, a partial layer can be

[0042] In this embodiment, the plastic can be structured by converting it into inorganic carbon.

[0043] Particularly preferred is a high-temperature-resistant plastic to which the laser-induced graphene process can be applied, and which is particularly suitable for 3D printing using bath-based photopolymerization. High-temperature-resistant plastics are particularly suitable for the LIG process due to their chemical composition and their processability at high temperatures. Targeted laser conversion of the organic material into graphene or graphite structures of carbon is possible here.

[0044] The plastic composition preferably comprises at least one monomolecular or oligomeric chemical species, each comprising at least one carbon-carbon double bond that is polymerizable by radical polymerization, wherein the monomolecular or oligomeric chemical species is present in a total amount of 25 to 99 wt.% based on the plastic composition.

[0045] The plastic composition preferably further comprises at least one photoinitiator, particularly preferably a titanocene photoinitiator, which is preferably present in a total amount of 0.1 to 15 wt.%, and furthermore at least one coinitiator, particularly preferably a thiol coinitiator, which is preferably present in a total amount of 0.5 to 20 wt.%.

[0046] Alternatively, the plastic composition comprises, for example, a thermosetting component A comprising one or more chemical species selected from the group consisting of monomers and / or oligomers and / or prepolymers of maleimide derivatives according to formula (I) and their isomers, wherein: n is an integer between 1 and 10, Ri represents H, CHs or CH2, and

[0047] R2 independently represents a linear, branched or cyclic aliphatic or aromatic C5-C40 radical from one or more of the groups phenyl, benzyl, phenethyl, methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decanyl, dodecanyl, acetic acid, propanoic acid, butanoic acid, pentanoic acid, undecanoic acid, dodecanoic acid, benzoic acid and corresponding esters, alkyl or aromatic esters, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl, isobornyl, propenyl, biphenyl, naphthyl, anthracenyl, pyrenyl, bis(methylene)oxy, bis(ethylene)oxy, bis(phenyl)methane, bis(phenyl)ethane, bis(phenyl)propane, bis(phenyl)butane, bis(phenyl)ether, bis(phenyl) thioether, bis(phenyl)amino or bis(phenyl)sulfone.

[0048] ( Formula I ) ,

[0049] Furthermore, the plastic composition then comprises a light-curable component B with one or more chemical species selected from the group of (meth)acrylate, (meth)acrylamide, vinyl ester, vinyl ether, vinyl, allyl, alkynyl or styrene compounds and their derivatives, substituted with at least one molecule from the group from which component A is selected, wherein the amount of component A is in the range from 30 wt.% to 95 wt.%, based on the total weight of components A and B, and the amount of light-curable component B is in the range from 5 to 70 wt.%, based on the total weight of components A and B.

[0050] Particularly preferably, component A then comprises a species of component A, where n is an integer from 2 to 10, which has an aromatic radical bonded to the N atom of the maleimide ring of formula I, preferably via a methylene group, in an amount in the range from 20 wt.% to 100 wt.%, preferably from 30 wt.% to 100 wt.% and even more preferably from 40 wt.% to 100 wt.%, based on the total weight of component A.

[0051] The partial layer in the plastic can be modified using a suitable process, particularly by converting it into inorganic carbon. Examples of such suitable processes include thermal processes, mechanical processes such as grinding or roughening, or ultrasonic processes, the application of plasma, irradiation using, for example, electron beams, lasers, UV-VIS radiation, IR radiation, X-rays, microwave radiation, and chemical processes such as etching or chemical activation of the surface.

[0052] For example, a partial layer in a plastic can be structured using a laser-induced graphene process. In the laser-induced graphene process, also known as the LIG process, the treated material is chemically and / or physically excited and altered by the action of laser radiation at the point of energy exposure. In particular, thermal transformation or decomposition occurs at the point of exposure.

[0053] In particular, in the LIG process, the organic carbon of the plastic is spatially converted into inorganic carbon modifications such as graphene, graphite or fullerenes by targeted energy input using laser radiation ("carbonization"). The LIG process is therefore generally not limited to the specific conversion of carbon into graphene, but can also include the conversion of carbon into other inorganic modifications. In particular, electrically conductive

[0054] Carbon structures are formed in the material layers. Furthermore, the aforementioned inorganic carbon modifications also differ in terms of their porosity and crystallinity.

[0055] In particular, the LIG process can be used to carry out modifications specifically on the surface of a material layer or to carry out modifications that penetrate deep into the material layer and, under certain circumstances, encompass the entire thickness of the partial layer.

[0056] In one embodiment, the material layer comprises auxiliary substances that support the laser-induced graphene process, such as catalysts, pre-doping agents or reactive groups.

[0057] Metal particles, metal salts or metal complexes dispersed in the layer can be used as catalysts.

[0058] In particular, the carbon materials to be produced and their derivatives can be used as pre-doping materials.

[0059] Reactive groups are found in various

[0060] For example, short-chain organic molecules with suitable reactive (end) groups such as aromatics are used.

[0061] The above-mentioned additives are preferably used in trace amounts. The process preferably runs without the explicit addition of additives. The additives may already be present in trace amounts in the raw materials used.

[0062] In one embodiment of the method, the structured sublayer is subjected to a post-treatment step to further modify the properties of the sublayer and, in particular, to enhance the properties established by modification. For this purpose, a surface treatment is preferably performed on a sublayer structured on the surface of the material layer.

[0063] The desired properties of the finished component can be adjusted during the additive manufacturing process.

[0064] In one embodiment in which the structured partial layer has at least an increased electrical conductivity compared to the remaining material layer, a possible post-treatment step comprises a surface treatment of the structured partial layer to further increase the electrical conductivity of the partial layer.

[0065] For example, surface treatment includes processes such as electroplating, sputtering or screen printing or partial steps thereof. However, surface treatment is not limited to the processes mentioned. In particular, metallic surface coatings with high electrical conductivity can be applied using the processes mentioned. The electrical conductivity of the partial layer can thus be significantly increased. Another surface treatment option is the application of a catalyst to enhance the catalytic properties of the modified material. In this context, a catalyst is any form of catalytically active material, which can be applied, for example, in powder form. The catalyst can in particular be applied to the surface or introduced into the pores of the modified material.

[0066] In an optional step, in one embodiment, a seed layer is applied to the surface of the structured sublayer prior to one of the aforementioned surface treatment steps. This seed layer serves as the basis for the subsequent surface treatment. In particular, such a seed layer can promote the application of metallic material and thus, for example, simplify and / or accelerate a galvanization process, a screen printing process, or a sputtering process. In particular, the seed layer can be a nanoscale seed layer.

[0067] In some embodiments, the structured partial layer has at least an increased porosity compared to the remaining material layer.

[0068] In an optional post-treatment step, conductive materials can then be introduced into the pores of the structured sub-layer, thus increasing the conductivity of the material.

[0069] In the embodiments, the post-treatment step is preferably carried out before applying the additional material layer. This allows each individual material layer to be specifically modified separately, or the modified properties to be enhanced.

[0070] The additive manufacturing itself, i.e. the additive application of the material layers (3D printing), can be carried out using any suitable manufacturing process such as vapor photopolymerization, material extrusion, material jetting, binder jetting, powder bed fusion, direct energy deposition or sheet lamination.

[0071] Due to its high precision, the Vat photopolymerization method is particularly suitable for the process described here.

[0072] In one embodiment, several sublayers in the material layer are structured in a single step. For this purpose, for example, a material layer is irradiated with several lasers to perform several LIG processes in parallel. Similarly, several sintering processes or similar modification steps can also be performed in parallel on several sections of the material layer.

[0073] Preferably, in the method, a component is formed from a plurality of material layers, wherein sublayers are then structured in a plurality of the material layers as described.

[0074] Preferably, no structured sublayer is formed in at least one material layer. Such a material layer can, in particular, consist of structural material. The structural material can be a non-modifiable material. Such a layer can, for example, increase the stability of the component or define the structure of the component.

[0075] The structured sublayers can be arranged arbitrarily or in a specific system. In one embodiment, the structured sublayers are arranged such that several sublayers of adjacent material layers are adjacent to one another. For example, several electrically conductive modified sublayers can be adjacent to one another in such a way that an internal electrode is formed in the component.

[0076] Between and / or after the aforementioned manufacturing steps, auxiliary steps can be carried out in any number and sequence in embodiments of the manufacturing process. In particular, these can be the steps of cleaning, washing, rinsing, neutralizing, activating, drying, etc. The exact selection and sequence depends, for example, on the product to be manufactured.

[0077] Component, its desired properties, the material used or the additive manufacturing process applied.

[0078] Particularly if the applied and modified material layers are present as green layers, debinding and sintering steps can follow.

[0079] Furthermore, in embodiments of the manufacturing process, further, usually final, steps may follow, which take place after the last material layer has been applied. These may include, for example, assembly, external metallization, insulation, painting, debinding, and sintering. The specific steps preferably depend on the component to be manufactured, its desired properties, the material used, or the additive manufacturing process employed.

[0080] The steps can be performed sequentially or simultaneously.

[0081] The present invention also relates to an electrical component manufactured according to the described method. Such a component can have all of the properties previously described in the course of the method.

[0082] In one embodiment, the component comprises a plurality of material layers, wherein several of the material layers comprise structured sublayers with increased electrical conductivity. In a preferred embodiment, no structured sublayer is formed in at least one material layer.

[0083] In particular, the electrical component can be designed as an electrical capacitor, e.g., as a plate capacitor. The plates of the capacitor are then preferably aligned vertically to the stacking direction of the additive manufacturing process. The internal electrodes of the capacitor are formed by several adjacent modified partial layers with increased electrical conductivity. Between them, each material layer contains unmodified sections with lower or no electrical conductivity.

[0084] The present invention further relates to an apparatus for carrying out the described process for manufacturing the component. The apparatus comprises at least one transport system and individual processing stations at which the steps of the process are carried out. The transport system is then designed such that the component can be transported from station to station during operation, or the stations can be moved to the component. Thus, all processing steps of the method can be carried out using one apparatus.

[0085] The invention is described in more detail below using exemplary embodiments and associated figures. The invention is not limited to the exemplary embodiments shown in the following figures.

[0086] Figure 1: Worktop with additively applied material layer.

[0087] Figure 2: Material layer after modification to form sublayers.

[0088] Figure 3: Post-treatment of the surface of the modified material layer.

[0089] Figure 4 : Component after application of a second material layer .

[0090] Figure 5: Component with two modified material layers.

[0091] Figure 6: Post-treatment of the surface of the second modified material layer.

[0092] Figure 7: Component after the application of a third material layer. Figure 8: Alternative embodiment of a component after the formation of sublayers in a first material layer.

[0093] Figure 9: Alternative embodiment of a component after the formation of sublayers in a second material layer.

[0094] Figure 10: Example of a component with different material layers arranged one above the other and next to each other in cross section.

[0095] Figure 11 : Another exemplary component with different material layers.

[0096] Figure 12 : Microscope image of porous LIG-modified plastic material .

[0097] Similar or apparently identical elements in the figures are designated by the same reference numerals. The figures and their proportions are not to scale.

[0098] Figures 1 to 7 show schematically an exemplary additive manufacturing process. In a first step, which is shown in Figure 1, a material layer 1 is applied to a work plate 2. The material layer 1 is applied using a suitable additive process. Examples of additive processes that are suitable here are VAT photopolymerization (VPP), material extrusion (MEX), material jetting (MJT), binder jetting (BJT), powder bed fusion (PBF), direct energy deposition (DED) and sheet lamination (SHL). The VPP process is particularly preferred due to its high printing accuracy. Other common additive processes can also be used.

[0099] For example, material layer 1 comprises a single homogeneous material. When constructing the subsequent material layers, the same homogeneous material can always be used in the further course of the process, so that all material layers comprise the same material.

[0100] Alternatively, two or more materials with different mechanical, electrical, optical, chemical, biological or toxicological properties can be used to construct a single or different material layers.

[0101] A material, for example, is a structural material that defines the mechanical properties of the component. Furthermore, the structural material can exhibit other desired properties, such as electrical or thermal properties. In addition to the structural material, a modifiable material that can be particularly easily converted into a conductive material can be present in the same layer or in further layers.

[0102] In a first example, material layer 1 is a plastic layer that comprises or consists of plastic materials. In addition to plastic, material layers made of natural materials, such as cellulose, are also conceivable.

[0103] The plastic layer can comprise modified natural materials such as rubber, viscose, or cellophane, or any industrially produced polymers such as polyimide (PI), polyethylene (PE), polypropylene (PP), and their derivatives such as PEI, etc. Both material layers made of uniform materials and chemically non-crosslinked mixtures (blends) of two or more materials are possible. Other possible materials include chemically crosslinked copolymers such as ABS, as well as composite materials such as GRP, PCB, and polymer materials with fillers such as polymers with embedded ceramic particles.

[0104] In a second process step, material layer 1 is modified in several sections. The modified layer is shown in Figure 2. The sections can be connected or separated. The sections can comprise any portion of the previously applied material layer 1. The sections and their dimensions can be specifically selected.

[0105] For example, the layer thicknesses of the material layers can be selected so that the desired properties of the layer composite are optimized to their target values. The geometric extent of the material layers can be controlled in the material application and modification steps. In particular, the individual layers can be additively applied in different forms in the first step. In the second step, the extent of sub-layers in a stacking direction of the material layers can also be changed by the modification. This means that both the structural material and the modifiable material can be present in one plane. In the first example, the modification of sub-sections of the material layer 1 is carried out using a LIG process. During this process, restructured sub-layers 3 are created in the corresponding sub-sections in the material layer 1.Partial layer 3 differs from the remaining material layer in at least one property. For example, partial layer 3 differs from the remaining material layer 1 in terms of its electrical conductivity or, for example, in terms of its porosity. Furthermore, partial layer 3 may alternatively or additionally also differ from the remaining material layer in terms of grain size or carbonization of the material.

[0106] In particular, the structured sublayer is electrically conductive, while the remaining material layer 1 is barely or not electrically conductive. Furthermore, the porosity of the structured sublayer 3 is higher than that of the remaining layer. A micrograph of the highly porous LIG-modified plastic material of sublayer 3 is shown in Figure 12.

[0107] The structuring can be carried out only on the surface of the partial layer 3 , over a part of the layer thickness or, as shown, over the entire layer thickness.

[0108] During the LIG process, the plastic material is thermally induced by a laser to chemically convert it, creating a structure based on inorganic carbon material. The structured sublayer can, for example, comprise a material based on graphene, graphite, fullerene, their (partially) oxidized derivatives, or the like. Preferably, the (organic) plastic material of the remaining material layer 1 is electrically non-conductive, and the material of the structured sublayer 3 is electrically conductive.

[0109] The LIG process can be supported by auxiliary materials such as suitable catalysts, pre-doping agents in material layer 1, and reactive groups introduced into material layer 1. Catalysts can be metal particles, metal salts, or metal complexes dispersed in material layer 1. Pre-doping agents can, in particular, be the carbon materials to be produced and their derivatives. Reactive groups can be short-chain organic molecules with suitable reactive (end) groups, such as aromatics.

[0110] The aforementioned excipients are used in trace amounts. Preferably, the process runs without the explicit addition of excipients. The excipients may already be present in trace amounts in the raw materials used.

[0111] In a third step, shown in Figure 3, the structured sublayer 3 is post-treated. In the present example, an electrically conductive metal such as copper, silver, gold, platinum, or palladium is applied to the pores of the sublayers 3 and / or as a thin film 4 on the surfaces of the sublayers 3 using a suitable process.

[0112] Such a suitable method can be a galvanic process such as electroplating, electroless plating, adsorption, etc. Alternatively, the application can also be carried out by sputtering, infiltration or screen printing.

[0113] The treatment of the surface is schematically indicated in Figure 3 by a cap 5 that covers the surface to be treated. This can, in particular, be an apparatus by means of which the surface treatment is carried out.

[0114] In an optional step, prior to the described surface treatment, a seed layer is applied to the surface of the structured sublayers 3, which serves as the basis for the subsequent surface treatment. In particular, such a seed layer can facilitate the application of metallic material and thus, for example, simplify and / or accelerate the electroplating process, the screen printing process, or the sputtering process. For example, the seed layer is a nanoscale seed layer.

[0115] 5 to 7, the further process steps of modifying the applied material layer 6 (Figure 5), post-treatment of the surface (Figure 6), and optionally applying further layers (Figure 7) are repeated once or several times. The partial layers 3 are preferably modified, as shown in Figure 5, in such a way that several partial layers of material layers arranged one above the other form a coherent structure. Optionally, a material layer 7 can also not extend over the entire surface of the underlying material layer, as shown in Figure 7. The material layers can optionally also be applied next to one another.

[0116] Figures 8 and 9 show an alternative embodiment. In this embodiment, the partial layers are structured partly only on the surface of the material layer and partly across the entire layer thickness.

[0117] The individual structured sublayers of several adjacent material layers are partially connected or, for example, form independent structures that are not connected. This is also illustrated in Figures 8 and 9. A structure can comprise a single sublayer.

[0118] Exemplary representations of finished components 10 with several superimposed material layers are shown in Figures 10 and 11. Figure 10 shows a cross-sectional view.

[0119] In this way, a component can be manufactured that comprises a plurality of material layers and sublayers Ia to If made of different materials. For example, Ie and If form a layer that comprises different materials. Using the method described above, electrically conductive structures can be patterned in the component. Thus, an electrical component can be manufactured additively without the need for further post-treatment steps. For example, a capacitor element, e.g. a plate capacitor, can be manufactured in this way.

[0120] In a second example, the material layer 1 comprises an organic material in which a ceramic material is embedded. The ceramic material includes a metallic element in its composition. The ceramic material is not further restricted. In the second step of the method, metallic and electrically conductive structures are then produced by targeted sintering of the ceramic material at selected sections of the ceramic layer. Furthermore, ceramic sublayers can be produced that no longer comprise any organic material.

[0121] In a third example, the material layer 1 comprises an organic material in which a metal is embedded, which is sintered in the second step of the method on selected sections of the material layer 1 in order to produce metallic sublayers as electrically conductive structures.

[0122] Between and / or after the aforementioned manufacturing steps, auxiliary steps can be performed in any number and sequence. These include, in particular, cleaning, washing, rinsing, neutralizing, activating, drying, etc. The exact selection and sequence depends on the component to be manufactured, its desired properties, the material used, the additive manufacturing process applied, etc.

[0123] Furthermore, final steps may follow, which take place after the last material layer has been applied. These may include, for example, assembly, external metallization, insulation, painting, debinding, and sintering. Here, too, the steps taken depend on the specific component to be manufactured, its desired properties, the material used, the additive manufacturing process used, etc.

[0124] The apparatus required for the described process can essentially consist of a transport system, such as a robot arm or conveyor belt, and individual processing stations. The component to be assembled can either be transported from station to station, or the stations can be moved to a fixed component to be assembled.

[0125] Essentially, the described method can be used to manufacture all conceivable products that consist of an additively applied organic material or plastic and optionally also of a ceramic material and / or a metal and have some type of electrical contact.

[0126] Additively manufactured components always comprise an additively deposited organic material and, optionally, embedded ceramic and / or metal particles. A modified sublayer can be further reinforced with a metallic surface coating such as Cu, Pd, Au, Ag, Ni, etc.

[0127] This allows a plastic component to be manufactured in which ceramic layers (for desired functionalities) and metallic layers (e.g., for electrical contact) are embedded. Thus, a multilayer component comprising plastics, ceramics, and metals can be produced through additive manufacturing, for example, through 3D printing, with modification steps.

[0128] An additively manufactured green body must finally be sintered to obtain the finished, ready-to-use component.

[0129] For example, passive electronic components can be manufactured, preferably multi-layered and with internal electrodes and with carrier substrates made of plastic, such as PCB, FR4 and / or ceramics such as AlOx or AIN, PZT, PLZT, PCZT, ferrite, varistor ceramics such as ZnO, PTC ceramics, NTC ceramics, LTCC, HTCC.

[0130] The described method can be used in one embodiment, for example, to produce a layer structure of a capacitor with internal electrodes.

[0131] For this purpose, a layer of plastic material is provided. A section of the surface of the plastic layer is modified so that its electrical conductivity changes compared to the plastic. The conductivity is specifically increased to form an electrode of the capacitor.

[0132] The modification is carried out, as previously described, by converting the plastic into a conductive carbon derivative using the LIG process. The modified sublayer is then reinforced by electroplating copper, further increasing its conductivity. The next plastic layer is then applied over the first layer of material.

[0133] This layer is then also modified to represent the next electrode layer, and so on, until the final process step, when another plastic layer is applied, which is not further modified. The modifications can extend across the entire material layer thickness.

[0134] The sublayers with increased conductivity then form the capacitor's internal electrodes. The sublayers are arranged so that sublayers of neighboring material layers adjoin each other, forming a coherent, uniform electrode structure.

[0135] Such an electrode structure, which forms the capacitor's inner electrode, then extends perpendicular to the stacking direction of the material layers. The intervening layer sections with lower conductivity act as separators.

[0136] This results in a component that has a first material layer on its underside that is only modified on its top side, followed by any number of material layers with modifications that form the actual capacitor, and an unmodified plastic layer as a final layer on its top side.

[0137] As additional auxiliary steps, unused raw material can be recycled after each material layer has been prepared, and the surface of the resulting material layer can be cleaned. The LIG process is then performed, followed by cleaning again. After electroplating, the material layer is neutralized, washed, rinsed, and dried.

[0138] If a ceramic-containing plastic material is used for the capacitor, such as ceramic particles embedded within a polymer matrix, debinding or sintering steps and shaping steps such as grinding can be followed at the end of the process.

[0139] At the end of the process, after all material layers have been applied, an external contact can be applied to the outside of the capacitor by sputtering or similar suitable processes, and the remaining surface of the capacitor can be coated with a protective coating / insulation. Additionally, the capacitor can be finished, e.g., cut to size, and an additional enclosure can be attached.

[0140] Reference symbol list

[0141] 1 First material layer

[0142] 2 worktop

[0143] 3 sub-layers

[0144] 4 Thin film

[0145] 5 Schematic cap for surface treatment

[0146] 6 Additional material layer

[0147] 7 Additional material layer with smaller dimensions

[0148] 10 Additively manufactured component la, 1b, 1c, Id, le , I f material layers

Claims

Patent claims 1. Additive manufacturing process encompasses the following steps: - additive application of a material layer (1) , - Modifying a part of the applied material layer (1) in a property such that a sublayer (3) in the The material layer (1) is structured, wherein the sublayer (3) differs from the rest of the material layer at least in its modified property.

2. Additive manufacturing process according to claim 1, comprising additively applying a further material layer (6) and modifying a part of the further material layer (6, 7) in a property such that a sub-layer (3) in the material layer (6) is structured, wherein the sub-layer (3) differs from the remaining material layer at least in the modified property.

3. Additive manufacturing process according to claim 2, wherein the material layer (1) and the further material layer (6) are applied directly on top of each other and / or next to each other.

4. Additive manufacturing process according to one of claims 1 to 3, wherein the material layer (1) consists of different materials, in particular structural material and modifiable material.

5. Additive manufacturing process according to any one of claims 1 to 4, wherein the material layer (1, 6, 7) comprises or consists of ceramic materials or comprises metals.

6. Additive manufacturing process according to claim 5, wherein the material layer (1, 6, 7) consists of metals.

7. Additive manufacturing process according to claim 5 or claim 6, wherein sintering is carried out in a part of the applied material layer (1, 6, 7) to structure the sublayer (3).

8. Additive manufacturing process according to any one of claims 1 to 7, wherein the material layer (1, 6, 7) comprises or consists of plastics.

9. Additive manufacturing process according to claim 8, wherein the plastics are resistant to high temperatures.

10. Additive manufacturing process according to claim 8 or according to claim 9, wherein in a part of the applied material layer (1, 6, 7) the plastic is converted into inorganic carbon to structure the sublayer (3).

11. Additive manufacturing process according to claim 10, wherein the sublayer is structured by a thermal process, thermal methods, irradiation by electron beams, lasers, UV-VTS radiation, IR radiation or X-ray radiation or microwave radiation.

12. Additive manufacturing process according to claim 10 or 11, wherein the sublayer is structured by a mechanical process, the application of plasma or a chemical process.

13. Additive manufacturing process according to claim 10 or 11, wherein a laser-induced graphene process is carried out in a part of the applied material layer (1, 6, 7) to structure the sublayer (3).

14. Additive manufacturing process according to claim 13, wherein the material layer (1, 6, 7) comprises auxiliary materials that support the laser-induced graphene process, such as in particular catalysts, pre-doping or reactive groups.

15. Additive manufacturing process according to any one of claims 1 to 14, wherein the structured sublayer (3) has at least an increased electrical conductivity compared to the rest of the material layer, comprising a post-treatment step for surface treatment of the structured sublayer (3) to further increase the electrical conductivity.

16. Additive manufacturing process according to claim 15, wherein the post-treatment step is carried out before the application of the further material layer (6, 7).

17. Additive manufacturing process according to one of claims 15 or 16, wherein a seed layer is applied to the surface of the structured sublayer (3) prior to the post-treatment step, which serves as a basis for the subsequent surface treatment.

18. Additive manufacturing process according to one of claims 15 to 17, wherein the surface treatment comprises a process step of electroplating, sputtering or screen printing.

19. Additive manufacturing process according to any one of claims 1 to 18, wherein the modified property is an electrical conductivity and / or a grain size distribution and the sublayer has at least an increased electrical conductivity and / or a modified grain size distribution compared to the rest of the material layer.

20. Additive manufacturing process according to any one of claims 1 to 19, wherein the modified property is a porosity and the sublayer has at least an increased porosity compared to the rest of the material layer.

21. Additive manufacturing process according to claim 19 or claim 20, wherein in a post-treatment step an electrically conductive or catalytically active material is introduced into pores of the sublayer ( 3 ).

22. Additive manufacturing process according to one of claims 1 to 21, wherein the application of the material layer ( 1 , 6 , 7 ) is carried out by means of one of the additive processes Vat photopolymerization, material extrusion, material jetting, binder jetting, powder bed fusion, direct energy deposition or sheet lamination .

23. Additive manufacturing process according to one of claims 1 to 22, wherein several sublayers ( 3 ) in the material layer ( 1 , 6 ) are structured in one step .

24. Additive manufacturing process according to one of claims 1 to 23, wherein a sublayer is structured only on the surface of a material layer or wherein the sublayer (3) is structured over the entire thickness of the material layer (1, 6).

25. Additive manufacturing process according to one of claims 1 to 24, wherein a component (10) is formed from several material layers (1, 6, 7, a1-f1), wherein sublayers (3) are structured in several of the material layers and no structured sublayer (3) is formed in at least one material layer (7).

26. Additive manufacturing process according to claim 25, wherein the structured sublayers (3) are arranged such that they form internal electrodes in the component.

27. Additive manufacturing process according to one of claims 25 or 26, wherein the applied and modified material layers (1, 6, 7, 1a-1lf) of the component (10) are debound and sintered in a further process step.

28. Additive manufacturing process according to one of claims 25 to 27, wherein further manufacturing steps follow for the manufacture of the component (10), such as in particular assembly, external metallization, insulation, painting, debinding and sintering, wherein the manufacturing steps are carried out successively or simultaneously.

29. Electrical component (10) manufactured according to a method of claims 1 to 28 and comprising several material layers (1, 6, 7, 1a-1lf), wherein several of the material layers are structured sublayers (3) with increased electrical conductivity or increased porosity or include a changed particle size distribution and no structured sublayer (3) is formed in at least one material layer (7).

30. Electrical component (10) according to claim 29, which is designed as an electrical capacitor.

31. Apparatus for carrying out the process according to claims 1 to 28 for manufacturing the component (10) according to claim 29 or 30, comprising a transport system and individual processing stations at which the steps of the process are carried out, wherein the transport system is designed such that in the operating state the component (10) can be transported from station to station or the stations can be moved to the component (10).

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