Build plate with high-temperature heating for the additive manufacturing of especially metallic and ceramic components.

Abstract

Build plate (1) with high-temperature heating for the additive manufacturing of, in particular, metallic and ceramic components, wherein at least one ceramic heating plate (2) is arranged below the build plate (1), which is composed of several heating plate segments (10, 10a, 10b, 10c) and has at least one electrical connection (7, 14) at the edge of each heating plate segment (10, 10a, 10b, 10c), which consists of a plate-side contact arrangement (7) and one or more connecting conductors (14), and which is arranged on an unheated plate finger (12, 13) of reduced area extending outwards from the edge of the heating plate (2) and in which one or more connecting conductors (14) in the heating plate segment (10, 10a, 10b, 10c) are electrically conductive with associated conductor tracks in the heating plate segment (10, 10a, 10b, 10c). 10c) are connected, characterized in that at least the area of ​​the plate finger (12, 13) is in the vicinity of the power connection (7,14) is actively cooled by a cooling arrangement (20).

Description

[0001] The invention relates to a building panel with high-temperature heating according to the preamble of claim 1.

[0002] A heated build plate is known, for example, from the subject matter of EP 3 747 634 B1. This is a method for manufacturing at least one component using 3D printing with a 3D printer.

[0003] The aforementioned publication uses a build plate with high-temperature heating, operating at temperatures ranging from 180 to 320°C. It is therefore not suitable for the generative or additive manufacturing of metallic and ceramic components that require build plate temperatures exceeding 500°C.

[0004] EP 0 711 496 B1 describes a ceramic heating element and a method for manufacturing such an element, consisting of layered blanks stacked on top of each other in a sandwich-like arrangement and sintered in a nitrogen atmosphere at a pressure of 50 to 70 bar and a temperature of up to 1,800°C to form a monolithic body. However, the specified manufacturing temperature for the ceramic heating plate cannot be used when assembling it with a build plate for the additive manufacturing of components because, as has been found, the electrical connections cannot withstand the high temperatures. The electrical connections either scale up, detach during operation, or are unable to transmit the necessary high heating currents.

[0005] DE 10 2008 051 478 A1 discloses a frame for a device for manufacturing a three-dimensional object, in which the frame is equipped with a surface heating system comprising several vertically arranged heating zones. The object is built up layer by layer from a powdered or liquid build-up material, the build space being defined by the frame and a platform located within it.

[0006] German patent DE 10 2013 001 374 A1 describes a device for the additive manufacturing of three-dimensional objects, in which layers of a powdered build material are solidified by means of electromagnetic radiation or particle radiation. This device comprises a support structure with a height-adjustable carrier arranged in a build chamber, and a build plate equipped with a heating device. The heating device consists of a plate-like carrier, the upper surface of which has a recess for a floating heating element, enabling targeted heating of the build plate.

[0007] DE 10 2019 214 489 A1 discloses a support arrangement for a selective powder melting process in which a heating system with at least one heating element heats the build plate. The support arrangement comprises a build plate that carries the object to be manufactured, and a base plate that is fixedly assigned to an external component of the system. A clamping system enables the build plate to be detachably connected to the base plate, with the heating system heating the build plate via the heating element, which is arranged above the base plate.

[0008] US 2020 / 0061922A1 describes a powder bed fusion device in which a heating element is integrated into or attached to the build platform. The device comprises a build sleeve, a build platform that supports a powder bed and can be lowered into the build sleeve, and a seal that prevents gaps from forming between the build platform and the build sleeve to prevent powder leakage. An inert atmosphere is maintained in the build chamber both above and below the build platform.

[0009] DE 10 2015 211 170 A1 discloses a heating device used for the production of a three-dimensional object by selectively solidifying powdered build material layer by layer on a build platform. This heating device consists of several heating elements and is connected to the build platform, being supplied with power via a first electrical connection. The heating device can be detachably attached to a support structure and has circumferential insulation.

[0010] German patent application DE 11 2018 002 838 B4 discloses a 3D printer designed for synthesizing 3D objects by extruding filament layers. The device comprises an extruder with a nozzle that extrudes filament layers onto a build surface, as well as a build platform and a removable build plate that is clamped to the build platform. The build platform consists of a base plate, a heating layer, a compressible preload element, and a clamp, which ensures uniform heat distribution from the heating layer across the build surface.

[0011] The known state-of-the-art solutions have several disadvantages, including inefficient heat distribution, inadequate cooling of the heating systems, complicated handling and maintenance, high energy costs, and limited adaptability to different materials. These shortcomings make existing systems less than optimal for the additive manufacturing of high-precision metallic and ceramic components, as they can lead to manufacturing defects, higher operating costs, and longer downtimes.

[0012] It is therefore an object of the invention to further develop a building plate with high-temperature heating of the type mentioned above in such a way that the electrical connections also operate reliably at building plate temperatures in the range of up to 1,000°C, without overheating or thermal damage occurring.

[0013] To solve the problem posed, the invention is characterized by the technical teaching of claim 1.

[0014] The invention is based on a building plate with a ceramic heating plate arranged directly or indirectly underneath it, which preferably consists of several heating plate segments, in particular preferably four heating plate segments, which are arranged in a horizontal plane and whose buttress edges meet as closely as possible in order to enable continuous, flat heating of the building plate above.

[0015] The heating plate is preferably made of silicon nitride or hot-pressed silicon nitride HPSN.

[0016] The heating plate is built up from various layers before sintering, preferably comprising at least one upper and one lower layer of electrically insulating silicon nitride and a middle layer containing the electrical heating conductors. In the case of cold zones, leads with a larger cross-section are incorporated as an additional layer between the contacts and the active heating conductor. After sintering, the layers preferably have a thickness of 0.65 mm and are completely monolithically sintered together, so that these layers can no longer be separated or delaminated from one another.

[0017] The electrical conductors preferably consist of an electrically conductive, doped silicon nitride and are monolithically sintered into the electrically insulating silicon nitride. The conductors are always located inside the heating plate and are thus completely covered. At the points where the ceramic contacts extend to the surface, solder pads made of electrically insulating silicon nitride are preferably soldered on; these pads contain the connecting wire and completely cover the electrically conductive ceramic (also as protection against oxidation).

[0018] The electrical conductors or connecting wires are attached to the contacts of the heating plate using an active soldering process. Since the ceramic is not wettable by metal, hard soldering cannot be used. Active soldering takes place at approximately 900°C in a high vacuum. During this process, an activator (Mo or Ti) in the solder alloy (Ag-Cu) bonds with the nitrogen and oxygen in the ceramic, creating a chemical bond at the interface between the surfaces.

[0019] It has been found that it is advantageous to relocate the electrical connections from the surface of the heating plate segment to cooler areas at the edges. This means that the electrical connections are no longer located within the heated surface of the heating plate segment, but rather outside of it. Preferably, a plate finger of reduced surface area extends from the heated edge of each heating plate segment, projecting beyond the heated edge. This finger, resembling an arm or finger, extends the surface and plane of the heating plate, but is itself unheated. It has proven advantageous to position the electrical connections in this unheated area of ​​the plate finger. This configuration has allowed for the handling of building plate temperatures up to 500°C. However, at building plate temperatures exceeding 500°C, it has been observed that the electrical connections located in the area of ​​the plate finger can no longer withstand the high temperatures continuously.

[0020] In a preferred embodiment of the invention, it is therefore provided that at least the area of ​​the unheated plate finger which is located in front of, at or below the power connection is actively cooled.

[0021] This technical teaching describes a completely new cooling method, because if the plate fingers, which are already unheated and pulled out of the heating area of ​​the heating plate segments, are additionally equipped with active cooling elements, it is possible to exceed the building plate temperature range of 500°C and to provide a building plate with a temperature of up to 1,000°C.

[0022] It has proven advantageous that the active cooling of the plate finger can be achieved in various ways near the respective electrical connection located on the plate finger. For orientation purposes, it is stated that the electrical connection to be cooled is preferably located on the upper side of the plate finger, although this is related to the orientation of the heating plate segment. If the heating plate segment is reversed, it is naturally located on the underside of the plate finger. For the sake of simplicity, it is therefore assumed that the electrical connection to be cooled is located on the upper side of the plate finger and that the active cooling can now be arranged in different areas of the plate finger. It is further assumed that the electrical connection to be cooled is located at the distal end of the uncooled plate finger.This does not preclude the existence of further surfaces of the plate finger beyond the plate finger – that is, behind the plate finger in the direction of heat flow. For the sake of simplicity, it is assumed that the electrical connection to be cooled is located at the distal end of the plate finger.

[0023] With regard to a build plate with heating for the additive manufacturing of, in particular, metallic and ceramic structures, reference is made to DE 10 2021 108 342 A1, the device described therein and the method carried out by the device are also the subject of the present application.

[0024] With regard to the additive manufacturing of metallic and ceramic components requiring high-temperature heating, reference is made to DE 10 2019 105 223 A1, the disclosure of which is said to be encompassed by the disclosure of the present invention. This also applies to the disclosure of the aforementioned DE 10 2021 108 342 A1.

[0025] A first embodiment of the present invention provides that the active cooling of the electrical connection is arranged upstream of the electrical connection on the plate finger in the direction of heat flow, whereby a region of 5 mm to 50 mm upstream of the electrical connection can be cooled. The cooling upstream of the electrical connection can take place either under or on top of the plate finger, provided that the electrical connection is arranged on the plate finger. The direction of heat flow is directed outwards from the heated surface of the heating plate towards the edge and into the cooled plate finger.

[0026] In another embodiment, the active cooling can be arranged directly below and opposite the power connection on the plate finger, so that heat dissipation through the material of the plate finger takes place downwards into the active cooling element.

[0027] In a third embodiment, one or more active cooling elements may be arranged around, in front of, and / or after the power connection and / or laterally next to the power connection. They can, in effect, form a frame that at least partially or completely surrounds the power connection.

[0028] All embodiments have in common that the sensitive power connection with high cooling capacity, together with the electrical connecting conductors arranged there, is cooled in such a way that the fastening of the connecting conductors in the power connection and their connection to the conductor tracks in the heating plate are not damaged by the high temperatures in the range between 500-1000 degrees Celsius.

[0029] Therefore, according to the subject matter of claim 2, the active cooling of the finger-like plate fingers consists of at least one cooling housing, which is thermally connected to the respective plate finger in accordance with the technical teaching of claim 1, and in which one end of heat-dissipating cooling fingers is arranged on the cooling housing, the other end of which is thermally connected to an externally cooled cooling plate arranged in the plate structure. The term "cooling housing" used here preferably refers to the ceramic solder plate with which the cooling elements are soldered to the cold zone of the heating plate in the area of ​​the plate fingers.

[0030] This technical teaching achieves that active cooling of the plate fingers, which is provided by an externally cooled cooling plate, is thermally connected to the plate finger in the area in front of and / or at and / or below and / or next to the power connection on the plate finger.

[0031] Such an externally cooled cooling plate can be permeated by a cooling medium. However, it can also incorporate Peltier elements whose cool sides are connected to the heat-dissipating cooling fingers.

[0032] Particularly effective cooling has been achieved when the power connection is located on the top of the plate finger and the opposite underside of the plate finger is actively cooled.

[0033] In a first embodiment, high-temperature heat pipes can be used as heat-dissipating cooling fingers. These are generally heat tubes acting as heat exchangers, which, by utilizing the enthalpies of vaporization of a medium, allow for a high heat flux density. In this way, large amounts of heat can be transferred over a small cross-sectional area. In addition to heat pipes, other heat tubes can also be used. Preferred designs for heat tubes are heat pipes and two-phase thermosiphons. All designs are referred to as cooling fingers in this description.

[0034] In a preferred embodiment of the invention, the heat pipes mentioned herein are designed as flexible hollow tubes containing a hermetically sealed volume. They are filled with a working medium, for example, water or ammonia, which fills the volume partly in liquid form and partly in gaseous form. The part of the heat pipe that absorbs energy is called the evaporator, and those that release energy are called the condenser. Accordingly, the invention provides that a number of heat pipes in the form of flexible hollow tubes are arranged in the region of one of the plate fingers, forming a thermally conductive contact with the cooling housing. The ends of one or more cooling fingers converge in this housing and thus act as evaporators.

[0035] The opposite ends of the cooling fingers form the condenser, which is thermally connected to the actively cooled cooling plate, which is arranged in the stack below the high-temperature building plate, separated by insulating plates.

[0036] The connection of the cooled ends of the cooling fingers to the cooling plate can be achieved, for example, via round bolts that protrude from the cooling plate and are encircled by the cooling fingers. Each cooling finger is therefore wrapped around the bolt-like cooling connection in the area of ​​the cooling plate and thermally connected in its upper, heat-absorbing part to a cooling housing on the plate side, which is located near or directly adjacent to the contact assembly to be cooled. When using heat pipes or two-phase thermosiphons, straight heat dissipation elements are employed, which do not require bending or encircling of bolts on the cooling housing.

[0037] In a further development of the invention, it can be provided that several cooling arrangements are present, wherein one cooling arrangement is arranged directly below the electrical connection to be cooled and another cooling arrangement is arranged in front of the electrical connection to be cooled on the upper side of the plate finger. In this way, a double cooling capacity is achieved, namely, firstly, the cooling of the plate finger in the area in front of the electrical connection to be cooled and, secondly, the cooling of the plate finger directly below or in the immediate vicinity of the electrical connection.

[0038] Instead of the heat pipes described here, which are filled with a medium, it is also possible in another design to use simple copper conductor wires with a solid cross-section or cooling elements made of graphene. For build plate temperatures above 500 to 600 degrees Celsius, it may be sufficient to design the cooling fingers as metal sheets or cooling pins. These designs are also thermally connected to the actively cooled cooling plate.

[0039] The use of heat-dissipating cooling fingers in the design as high-temperature cooling fingers in the form of a heat pipe or heat tube has the advantage that temperatures of the build plate up to 1,000°C can be controlled, while when using copper fingers or graphene fingers, temperatures up to a range of 800°C can be controlled.

[0040] Segmenting a heating plate into preferably four segments offers the advantage that each segment can be assigned its own power supply, and this supply can be cooled separately, thus improving the reliability of the power supply. Dividing the power into four segments reduces the current density per connection and consequently the amount of additional heat generated in the plate fingers.

[0041] With a standard panel size of 280 x 280 mm, the individual segments of the heating plate are correspondingly 140 x 140 mm. Since the invention also includes round or other shapes, the external dimensions can vary considerably or be described as rectangular, e.g., 250 to 500 mm square, or round up to Ø500 mm.

[0042] A further advantage of the invention lies in the fact that the heating plate segments are preferably embedded in a contact plate made, for example, of steel, ceramic, or molybdenum with good thermal conductivity. This ensures a uniform distribution of heat energy across the entire building plate, so that its entire surface, including the edge areas, can be kept at an approximately uniform temperature. The contact plate is thermally coupled to the building plate via material contact.

[0043] In thermal coupling, it can also be provided that heat transfer takes place both via material contact and via convection.

[0044] In a further development process, it may be stipulated that, to prevent cold spots, the areas of the plate segments where the cooled plate fingers are attached are heated with a higher heat output than the other plate areas. Since the cooled plate fingers transfer cooling power to the heated plate segments, it may therefore be necessary to increase the heating power in this edge transition area of ​​the plate segments. Furthermore, an increased surface power output can be provided at the outer edges of the heated plate segments to compensate for the higher heat loss due to convection at the edge of the building plate.

[0045] Tests with build plates of 3D printers for the additive manufacturing of components have shown that it is sufficient for each plate segment to have preferred dimensions of 250 x 250 mm with a preferred thickness of 5 to 6 mm.

[0046] Further features of the invention are the subject of the remaining dependent claims.

[0047] The subject matter of the present invention is not only derived from the subject matter of the individual patent claims, but also from the combination of the individual patent claims with one another.

[0048] All information and features disclosed in the documents, including the abstract, and in particular the spatial configuration shown in the drawings, could be claimed as essential to the invention, insofar as they are novel individually or in combination compared to the prior art. The use of the terms "essential," "inventive," or "essential to the invention" is subjective and does not imply that the features so designated must necessarily be part of one or more patent claims.

[0049] The invention is explained in more detail below with reference to drawings illustrating several embodiments. Further essential features and advantages of the invention will become apparent from the drawings and their description.

[0050] They show: Fig. 1: Perspective view of a building panel with heating according to the state of the art Fig. 2: A section through a heating plate segment with active cooling of the electrical connections according to the invention Fig. 3: A top view of a heating plate segment after Fig. 2 Fig. 4: Side view of the heating plate segment after Fig. 3 Fig. 5: The underside view of the heating plate segment after Fig. 3 and Fig. 4 Fig. 6: The perspective bottom view of the plate fingers of a heating plate segment in enlarged view Fig. 7: FEM temperature calculation of the temperatures generated at the heating plate segment during active cooling in cross-section Fig. 8: The calculation of the temperature distribution in the heating plate segment using FEM according to Fig. 7 Fig. 9: A preferred embodiment, which is equipped with the Fig. 3 essentially agrees Fig. 10: One opposite Fig. 9 modified embodiment of a heating plate segment Fig. 11: A second embodiment of a heating plate segment Fig. 12: A third embodiment of a heating plate segment Fig. 13 - 14: Side view and top view of the cooled plate finger with cooling fingers in the form of metallic wires Fig. 15 - 16: One to Fig. 13-14 modified version with metal sheets as cooling fins Fig. 17-18: One to Fig. 13-14 modified version with cooling pins as cooling fingers

[0051] The Fig. Figure 1 therefore shows a construction plate 1 according to the prior art, as can be seen, for example, in our own DE10 2021 108 342 A1. The construction plate 1 consists of a stacked structure, wherein a contact plate 6 made of a highly thermally conductive material is arranged below the construction plate 1, below which in turn a heating plate 2 is arranged, which is supplied with current by electrical connections not shown in detail, wherein the meandering current paths laid in the heating plate 2 ensure a uniform heating of the surface of the construction plate 1.

[0052] Beneath the heating plate 2 is an insulating plate 3 made of a heat-insulating material, and beneath the insulating plate 3 is a cooling plate 4 containing a cooling medium. As stated in the general section, this can be active cooling with a cooling medium, but also electrical cooling using Peltier elements.

[0053] The entire stack structure 1, 2, 3, 4 is arranged on a lifting frame 5, which is lowered step by step according to the additive manufacturing process according to DE10 2021 108 342 A1 in order to enable layer-by-layer superposition of the individual layers to be joined together in the SLM or SLS process.

[0054] One in Fig. The building plate 1 shown, with its layered structure of individual elements 2, 3, 4, was, with the contact arrangement 7 (not shown in detail), at best usable for temperatures up to 500°C. Higher temperatures could not be withstood, particularly due to the possibility of damage to the contact arrangement 7.

[0055] For this reason, the invention proposes active cooling of the contact arrangement 7, which results from the section in Fig. 2 results. The intersection in Fig. 2 is the section through a heating plate segment 10, which is shown in top, side and bottom view in the Fig. Figures 3-5 are shown. A total of four such heating plate segments 10 then form the heating plate 2, and the individual heating plate segments 10 are located close together, with the electrical current connection being made separately in each heating plate segment 10.

[0056] In this way, it is possible to create four different heating zones on the heating plate 2, while ensuring uniform heating of the entire surface of the building plate 1. This means that the heating power in the individual heating plate segments 10 is as equal as possible, although this is not essential for the solution.

[0057] The Fig. Figures 2-5 now show that edge-side plate fingers 12, 13 are derived from the surface of the respective heating plate segment 10, which are spatially separated from each other by a plate-side recess 11. In the embodiment according to the Fig. 3 - 5 the plate fingers 12, 13 are arranged at an angle of 90° to each other.

[0058] In the Fig. 11 and Fig. Figure 12 shows a different arrangement.

[0059] Out of Fig. 2 in conjunction with Fig. Figure 4 shows that the current-carrying connecting conductors 14 are brought together in a contact arrangement 7 on the upper side of the respective plate finger 12, 13, wherein the electrical connection 8 of the connecting conductors 14 establishes the electrical connection with the current-carrying conductor tracks in the interior of the heating plate segment 10.

[0060] The contact arrangement 7 essentially consists of actively soldered contact connection points, which connect the ends of the electrical connecting conductors 14 with the current-carrying conductor tracks in the interior of the heating plate segment 10.

[0061] The contact arrangement 7 is preferably arranged on the upper side of the respective plate finger 12, 13, which itself is not cooled. Fig. As shown in Figure 5, the heating plate segment 10 is heated in its hatched area 18, while the plate fingers 12, 13 extending from the heated area form a cold area 17. This contains the leads between the contacts and the active heating conductor, which generate a minimal heating power due to their larger cross-section.

[0062] Because the contact arrangement 7 is preferably arranged on the top of the plate fingers 12, 13, the current-carrying connecting conductors 14 are directed downwards at an angle of 90° below the heating plate 2 at its edge and are connected to current supply lines not shown in detail.

[0063] Because of the top-mounted arrangement of the contact assembly 7 to be cooled, the Fig. 2 - 5, that it is advantageous to now provide the underside of the plate fingers 12, 13 near the contact arrangement 7 with active cooling.

[0064] The general description stated that active cooling can be achieved using cooling fingers 16, and described various locations for attaching a cooling housing 15 that combines the cooling fingers. The term "cooling housing" therefore refers only to the thermally conductive connection of the ends of the cooling fingers that attach to the plate finger. The "cooling housing" is preferably a ceramic solder plate to which the cooling elements are soldered to the cold zone of the heating plate.

[0065] In the illustrated embodiment, the cooling housings 15 of the plate fingers 12, 13 are arranged directly below the contact arrangement 7 to be cooled.

[0066] The cooling housing 15 is in Fig. Figure 4 shows only the perspective view of the contact arrangement 7. The contact arrangement 7 is the fastening element (solder plate) for the active cooling arrangement 20 or the cooling fingers 16.

[0067] The Fig. Figure 5 shows that undesirably cold areas can form at the connection point of the plate fingers 12, 13 on the edge of the heating plate segment 10 due to the uncooled plate fingers 12, 13. To avoid such cold areas, a higher density of conductive traces can be arranged in the edge plate area 22, which surrounds the connection point of the plate fingers 12, 13 to the heated area 18, in order to heat this plate area 22 with a higher heat output. This ensures that the edge area of ​​the heating plate segment 10, which extends around the recess 11, is also heated uniformly and kept at the same temperature as the rest of the heated area 18.

[0068] Out of Fig. Further details of the arrangement can be found in Figure 6. It can be seen there that the current-carrying connecting conductors 14 are bent downwards at an angle of 90° over the respective end face 21 of the plate finger 12, 13 and are connected to current sources not shown in detail.

[0069] Furthermore, it is shown that the cooling fingers 16 are heat pipes which - according to the general description - are highly thermally conductive elements that are able to transfer heat from the cooled cooling connection 19 (see Fig. 2) to enable good heat transfer from the underside of the plate fingers 12, 13 to the cooling plate 4.

[0070] The Fig. Figure 7 shows a cross-sectional view through the arrangement according to Fig. 2 the resulting temperature distribution, where it can be seen that the cooling housing 15a located upstream of the contact arrangement 7 to be cooled, with the cooling finger 16a arranged there, provides for initial heat dissipation even before the contact arrangement 7 to be cooled, and that below the contact arrangement 7 the second cooling arrangement is arranged with the cooling housing 15 and the cooling fingers 16 which are thermally connected to one end in the cooling housing 15, the opposite heat-emitting ends of which are thermally guided via associated bolt-like cooling connections 19, which are thermally connected to the cooling plate 4.

[0071] The temperature distribution calculated by the FEM calculation shows that the temperature at the heat-dissipating cooling connections 19 is approximately 59°C, while an insulation plate 3 arranged between the cooling plate 4 and the heating plate 2 has a temperature in the range of approximately 500 to 600°C.

[0072] A spacer plate 9 is also present, on which the heating plate 2 is placed and to which it is thermally connected. The spacer plate has a temperature in the range of approximately 600 to 700°C, while the heating plate 2 reaches a temperature of 925°C, resulting in a working temperature on the surface of the build plate in the range of 700 to 800°C.

[0073] Cooling plate 4 has a temperature of approximately 30°C.

[0074] Another FEM calculation of the temperature distribution shows the top view in Fig. 8, where it can be seen that the active cooling arrangement 20, which preferably consists of the cooling housings 15, 15a and the cooling fingers 16, 16a, now provides a temperature in the range of about 540°C, and a considerable temperature gradient is visible in the longitudinal extent of the plate fingers 12, 13. In Fig. 8 below the recess 11, parts of the cooling plate 4 are also shown, through which heat is dissipated from the cooled contact plates 6.

[0075] The Fig. Figures 9-12 show different shapes of heating plate segments 10, preferably depicted in a quartered configuration. A majority of the heating plate segments 10, 10a, 10b, 10c shown are assembled to form a full-surface, square or rectangular heating plate 2. Besides the quartered arrangement of such heating plate segments 10, 10a, 10b, 10c, other subdivisions are of course possible, e.g., halved or thirded heating plate segments.

[0076] While the Fig. 9 and Fig. 10 the separate division of 2 plate fingers 12, 13 arranged at an angle of 90° to each other show, show the Fig. 11 and Fig. 12, that it is also sufficient to pull out a single plate finger 12 from the plane of the heating plate segment 10b, 10c and to cool this plate finger 12 using the measures of the invention.

[0077] The Fig. Figures 13-18 show various designs of cooling fingers that are not designed as highly thermally conductive heat pipes or heat conduction tubes, but rather simpler cooling fingers suitable for the lower temperature ranges of the build plate, e.g., 350 degrees Celsius to 600 degrees Celsius.

[0078] The Fig. 13 and Fig. Figure 14 shows cooling fingers 16 in the form of metallic wires, preferably made of copper or graphene, in side view and top view.

[0079] The Fig. 15 and Fig. Figure 16 shows cooling fingers 16b in the form of thin sheets and the Fig. 17 and Fig. Figure 18 shows cooling fingers 16c in the form of cooling pins, each in side view and top view.

[0080] The Fig. Figure 18 shows that the cooling pins can also be designed as tubular cooling fingers 16c in the manner of so-called heat tubes. Drawing legend 1 building plate 2 heating plates 3 Insulation board 4 cooling plates 5 lifting frame 6 Contact plate 7 Contact arrangement 8 electrical connection 9 spacer plate 10 heating plate segments 11 Exclusion (in 10) 12 plate fingers 13 plate fingers 14 connecting conductors 15 cooling housings 16 cooling fingers 16a, 16b, 16c 17 cold area 18 heated areas 19 cooling connections (in 4) 20 active cooling arrangement 21 Front side (of 12, 13) 22 plate area (higher heat)

Claims

[1] Build plate (1) with high-temperature heating for the additive manufacturing of, in particular, metallic and ceramic components, wherein at least one ceramic heating plate (2) is arranged below the build plate (1), which is composed of several heating plate segments (10, 10a, 10b, 10c) and at least one electrical connection (7, 14) is arranged at the edge of each heating plate segment (10, 10a, 10b, 10c), which consists of a plate-side contact arrangement (7) and one or more connecting conductors (14), and which is arranged on an unheated plate finger (12, 13) of reduced area extending outwards from the edge of the heating plate (2) and in which one or more connecting conductors (14) in the heating plate segment (10, 10a, 10b, 10c) are electrically conductive with associated conductor tracks in the heating plate segment (10, 10a, 10b, 10c) are connected, characterized by, that at least the area of ​​the plate finger (12, 13) near the power connection (7, 14) is actively cooled by a cooling arrangement (20). [2] Building plate (1) according to claim 1, characterized by , that the active cooling (4, 15, 16) of the plate fingers (12, 13) consists of heat-dissipating cooling fingers (16, 16a-c) which are connected to at least one externally cooled cooling plate (4) in a heat-dissipating manner. [3] Building plate (1) according to claim 2, characterized by , that the heating plate-side ends of the plate fingers (12, 13) are brought together in a cooling housing (15), and that on the cooling housing (15) one ends of the heat-dissipating cooling fingers (16, 16a-c) are arranged, the other ends of which are connected in a heat-dissipating manner to at least one externally cooled cooling plate (4) arranged in the plate structure (1, 2, 3, 4). [4] Building plate (1) according to one of claims 1 to 3, characterized by, that the power connection (7, 14) is located on the top of the plate finger (12, 13) and that the opposite underside of the plate finger (12, 13) is actively cooled by the cooling arrangement (20). [5] Building plate (1) according to one of claims 2 to 3, characterized by , that the heat-dissipating cooling fingers (16) are designed as liquid-filled high-temperature heat pipes or as liquid-filled heat tubes. [6] Building plate (1) according to one of claims 2 to 3, characterized by , that the heat-dissipating cooling fingers (16a, 16b, 16c) are formed from wire- or strip-shaped graphene or copper conductors. [7] Building plate (1) according to any one of claims 1 to 6, characterized by that the building plate (1) has a surface temperature of up to 1000 degrees Celsius in the heated area, preferably a temperature in the range of 800 degrees Celsius. [8] Building plate (1) according to any one of claims 1 to 7, characterized by, that the heating plate segments (10, 10a, 10b, 10c) are embedded in a contact plate (6) made of steel, ceramic or molybdenum with good thermal conductivity. [9] Building plate according to claim 8, characterized by , that the contact plate (6) is thermally coupled to the building plate (1) via material contact. [10] Building plate according to claim 8 or 9, characterized by , that the heat transfer between contact plate (6) and build plate (1) takes place via material contact. [11] Building plate according to any one of claims 1 to 10, characterized by , that each plate segment (10) has preferred dimensions of 250 x 250 mm with a preferred thickness of 5 to 6 mm. [12] Building plate according to any one of claims 1 to 11, characterized by , that to avoid heat loss under the heating plate (2, 10) a thermal insulation with an insulation plate (3) is arranged and that the cooling plate (4) is arranged below the insulation plate (3). [13] Building plate according to any one of claims 1 to 12, characterized by , that at least the area of ​​the plate finger (12, 13) which is in front of or on or below or next to the power connection (7, 14) is actively cooled.

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