Conformal multilayer ceramic circuit integrated forming equipment and method based on SLM and laser etching

Abstract

The invention discloses conformal multilayer ceramic circuit integrated forming equipment and method based on SLM and laser etching, and belongs to the field of additive manufacturing, the equipment comprises a five-axis movement system, an automatic ceramic powder laying and recycling system, a ceramic SLM forming system, a ceramic surface conductive pattern printing system, a laser etching system and a control system; according to the method, a five-axis movement system serves as a basic movement system of the whole equipment, and an automatic ceramic powder laying and recycling system, a ceramic SLM forming system, a ceramic surface conductive pattern printing system and a laser etching system are arranged at different positions of the five-axis movement system respectively and controlled through a control system, so that all the systems are matched with one another, and the ceramic surface conductive pattern is formed. Powder laying, ceramic manufacturing and conducting layer material adding on the ceramic surface are sequentially carried out, finally, antenna circuit pattern etching is carried out on the ceramic with the conducting metal layer printed on the surface, and the integrated in-situ forming multi-layer ceramic circuit is completed. The process is simple, one-time in-situ forming is achieved, and the ceramic shrinkage rate is low.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing, and in particular relates to a conformal multilayer ceramic circuit integrated forming device and method based on SLM and laser etching. Background Art

[0002] Selective laser melting (SLM) technology is one of the ceramic additive manufacturing (AM) technologies. Laser etching technology uses a low-power laser to etch the required circuit pattern on the metal coating. It processes in a non-contact laser way. After focusing the laser to a very small spot at the laser wavelength level, the laser is scanned in a certain path on the material surface according to the designed pattern to obtain the required pattern, that is, the excess coating except the circuit is removed by laser on the silver or copper coating of the workpiece, leaving the required conductive pattern. This method is easy to operate, pollution-free, non-contact, low process cost, high manufacturing precision and other advantages that other technologies cannot match. SLM technology refers to the complete melting of ceramic oxide powder under the action of high temperature laser, and then cladding on the surface of the base ceramic. After cooling and solidification, a new layer of ceramic is formed. After repeated steps such as powder spreading, melting, and resolidification, a ceramic three-dimensional entity can be formed layer by layer. Compared with other ceramic three-dimensional forming technologies, this technology has the advantages of fast forming speed and the ability to process samples with complex shapes and structures, and has broad development prospects.

[0003] At present, the mainstream ceramic additive manufacturing technology mainly includes the ceramic 3DP manufacturing technology based on binders. For example, the Chinese patent application with publication number CN116730739A discloses a 3DP manufacturing method for alumina ceramic parts based on aluminum chloride as a binder. This method uses 3DP prefabricated powder and binder to make ceramic green bodies and then sinter them. However, the green bodies need to be degreased and sintered at high temperature. The process is cumbersome, and it is impossible to form in situ at one time. In addition, the ceramic shrinkage rate is large. The current mainstream application of SLM technology is the manufacture of metals. For example, the Chinese patent application with publication number CN113843419A discloses a method for preparing in-situ generated TiC+Ti3SiC2 reinforced titanium-based composite materials by selective laser melting. However, this method is only applicable to the manufacture of TiC metals and cannot manufacture silica ceramics. At present, multilayer ceramic circuits are generally manufactured using the LTCC method. For example, Chinese patent application with publication number CN119263796A discloses high-density and high-strength LTCC raw ceramic sheets and their preparation methods and applications. However, they require tape casting and co-firing steps, which are cumbersome processes, and the ceramics are prone to shrinkage, which can lead to performance failure.

[0004] In summary, the problems with existing patents and technologies are: Currently, SLM technology is mainly used to manufacture metals, while in the field of ceramic SLM, this technology is still in its infancy. Compared with metal SLM molding technology, the high brittleness of ceramics makes it more difficult to use SLM technology to manufacture ceramics, and the manufacturing equipment and methods are very different from metal SLM. There is currently no relevant technology for using SLM technology to integrate in-situ manufacturing of ceramics as antenna substrates and manufacturing multilayer ceramic circuits. Summary of the invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide an integrated forming device and method for conformal multilayer ceramic circuits based on SLM and laser etching. Ceramic powder is laid on a conformal substrate by spraying slurry or a conformal scraper, and then laser melting is used to form ceramics. On the basis of the ceramic, a piezoelectric nozzle and a laser are used to add a conductive pattern, and then the conductive pattern is laser melted again to form ceramics, finally forming a conformal multilayer ceramic circuit. The process is simple, one-time in-situ forming is achieved, and the ceramic shrinkage rate is low.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A conformal multilayer ceramic circuit integrated forming device based on SLM and laser etching, comprising an optical platform 19, a gantry structure configured with the optical platform 19, and also comprising a five-axis motion system 1, an automatic ceramic powder spreading and recycling system 2, a ceramic SLM forming system 3, a ceramic surface conductive pattern printing system 4, a laser etching system 5 and a control system 6;

[0008] The five-axis motion system 1 is arranged on the optical platform 19 and the gantry structure, and as the basic motion system of the whole equipment, it provides motion in the directions of X-axis 11, Y-axis 12 and Z-axis 13 for the automatic ceramic powder spreading and recycling system 2, the ceramic SLM molding system 3, the ceramic surface conductive pattern printing system 4 and the laser etching system 5;

[0009] Automatic ceramic powder laying and recycling system 2 is used to lay powder or recycle excess powder;

[0010] The ceramic SLM forming system 3 is used to form ceramics from the powder laid by the automatic ceramic powder laying and recycling system 2;

[0011] The ceramic surface conductive pattern printing system 4 is used to add a conductive layer on the ceramic surface prepared by the ceramic SLM molding system 3;

[0012] The laser etching system 5 is used to etch the antenna circuit pattern on the ceramic on which the conductive metal layer is printed by the ceramic surface conductive pattern printing system 4;

[0013] The control system 6 is used to control the five-axis motion system 1, the automatic ceramic powder spreading and recycling system 2, the ceramic SLM forming system 3, the ceramic surface conductive pattern printing system 4 and the laser etching system 5 to realize the conformal multilayer ceramic circuit integrated forming process.

[0014] The five-axis motion system 1 comprises an X-axis 11, a Y-axis 12 and a Z-axis 13, and a motion platform is slidably connected to each of the X-axis 11, the Y-axis 12 and the Z-axis 13, and the motion platform slides along the axial direction;

[0015] The X-axis 11 is fixed on the transverse connecting plate 17 of the gantry structure, and the Z-axis 13 is fixedly arranged on the motion platform of the X-axis 11. The X-axis 11 and the Z-axis 13 form a cross structure, and a grating ruler 111 is fixedly connected to the side of the X-axis 11, and a cross adapter plate 18 is fixedly connected to the side of the Z-axis 13 away from the X-axis 11;

[0016] The Y-axis 12 is fixed on the optical platform 19. The moving platform of the Y-axis 12 is fixedly connected to the hollow rotating platform. The hollow rotating platform includes a hollow rotating platform C15 and a hollow rotating platform A14. Both the hollow rotating platform C15 and the hollow rotating platform A14 have built-in servo motors for driving the platforms to rotate. The fixed end of the hollow rotating platform C15 is fixedly connected to the moving platform of the Y-axis 12, and the rotating end of the hollow rotating platform C15 is connected to the fixed end of the hollow rotating platform A14.

[0017] The X-axis 11 and the Y-axis 12 are perpendicular to each other and parallel to the optical platform 19 , and the Z-axis 13 is perpendicular to the optical platform 19 .

[0018] The automatic ceramic powder spreading and recycling system 2 includes a gas-liquid two-phase nozzle 215 and a conformal scraper 212 fixed on the cross adapter plate 18, and a conformal substrate 211 fixed on the rotating end of the hollow rotating platform A14. A powder outlet bin 213 and a powder inlet bin 214 are respectively arranged on both sides of the conformal substrate 211, and the powder inlet bin 214 is arranged at a height lower than the conformal substrate 211;

[0019] The gas-liquid two-phase nozzle 215 is connected to the slurry barrel 216;

[0020] The conformal scraper 212 is fitted with the curved surface of the conformal substrate 211, and a porous sponge strip is attached below the curved surface of the conformal scraper 212;

[0021] The conformal substrate 211 is a developable curved surface or a non-developable curved surface substrate made of high-purity graphite with a content of more than 99.9% or 6061 aluminum alloy or silicon dioxide crystal.

[0022] The ceramic SLM molding system 3 includes a powder bed heating device 31, a three-dimensional laser dynamic focusing scanning device 32, and a laser displacement sensor 33;

[0023] The powder bed heating device 31 is disposed inside the conformal substrate 211;

[0024] The three-dimensional laser dynamic focusing scanning device 32 is arranged above the Y-axis 12, and is connected to the motion platform of the laser scanning device fixed axis 35 through the adapter plate 34. The motion platform of the laser scanning device fixed axis 35 is slidably connected to the laser scanning device fixed axis 35 and slides along the axial direction of the laser scanning device fixed axis 35. The laser scanning device fixed axis 35 is vertically fixed on the optical platform 19.

[0025] The laser displacement sensor 33 is fixed to the bottom end of the cross adapter plate 18 .

[0026] The ceramic surface conductive pattern printing system 4 includes a near-infrared curing device 41, a piezoelectric nozzle 42, and a nano silver paste storage barrel 43;

[0027] The near-infrared curing device 41 is disposed above the Y-axis 12 and fixed on the optical platform 19;

[0028] The piezoelectric nozzle 42 is fixed to the bottom end of the cross adapter plate 18;

[0029] The nano silver paste storage bucket 43 is placed above the optical platform 19 and is connected to the piezoelectric nozzle 42 .

[0030] The laser etching system 5 is composed of some equipment of the ceramic SLM molding system 3 , including a powder bed heating device 31 and a three-dimensional laser dynamic focusing scanning device 32 .

[0031] The control system 6 is composed of a display panel 61, a multilayer ceramic forming button 62, a separate process button 63, a control system panel main frame 64, and a single-chip microcomputer 65. The display panel 61, the multilayer ceramic forming button 62, the separate process button 63, and the single-chip microcomputer 65 are installed on the corresponding positions of the control system panel main frame 64 by inlaying. The control pins corresponding to the components in the multilayer ceramic forming button 62, the separate process button 63, the five-axis motion system 1, the automatic ceramic powder laying and recycling system 2, the ceramic SLM forming system 3, the ceramic surface conductive pattern printing system 4, and the laser etching system 5 are respectively connected to the pins of the single-chip microcomputer 65, so that the single-chip microcomputer 65 controls the system in the equipment through buttons to complete the corresponding process.

[0032] A method for integrally forming a conformal multilayer ceramic circuit comprises the following steps:

[0033] Step 1: Control the gas-liquid two-phase nozzle 215 to move along the X-axis 11 at a speed of 40 mm / s to 60 mm / s through the control system 6, and spray the ceramic slurry on the conformal substrate 211 at a spray flow rate of 20-25 L / h, or use the conformal scraper 212 to adsorb the dry silica ceramic powder on the powder discharge bin 213, and lay 50 to 100 microns of dry silica ceramic powder on the conformal substrate 211;

[0034] Step 2: Prepare ceramics through the SLM molding system 3: Use the powder bed heating device 31 to heat the ceramic slurry or ceramic powder on the conformal substrate 211 until the multilayer ceramic circuit is completed, the heating temperature is 300-500°C, and the control system 6 controls the conformal substrate 211 to move below the three-dimensional laser dynamic focusing scanning device 32, and then use the three-dimensional laser dynamic focusing scanning device 32 to scan and melt the ceramic material on the conformal substrate 211 to form ceramics, and use the laser displacement sensor 33 to measure the thickness of the ceramic layer. If the required layer thickness is reached, the ceramic forming process is stopped and step 3 is performed;

[0035] Step 3: Control the movement of the piezoelectric nozzle 42 and the conformal substrate 211 by the control system 6, spray the nano silver paste on the ceramic surface of the conformal substrate 211 by the piezoelectric nozzle 42, and then move the conformal substrate 211 to the top of the near-infrared curing device 41 for sintering to form a conductive layer;

[0036] Step 4: Control the conformal substrate 211 to move to below the three-dimensional laser dynamic focusing scanning device 32 through the control system 6, and use the laser to etch the required circuit pattern;

[0037] Step 5: After the circuit pattern is etched, return to step 1 and perform a new round of forming process to finally complete the forming of the multilayer ceramic circuit.

[0038] The ceramic slurry described in step 1 is silicon dioxide, and its preparation method comprises:

[0039] Step 1.1: Mixing silicon dioxide powder with a particle size of 10 micrometers to 40 micrometers and carbon black powder with a particle size of 20 nanometers to 50 nanometers in a mass ratio of (20-40):1;

[0040] Step 1.2: Add 5 to 10 times the mass of deionized water to the mixture obtained in step 1.1;

[0041] Step 1.3: After the mixture after adding deionized water in step 1.2 is initially stirred, the mixture is stirred at a speed of 3000 to 6000 revolutions per minute using a stirrer for 30 to 60 minutes to finally prepare a silica ceramic slurry.

[0042] Compared with the prior art, the beneficial effects of the present invention are:

[0043] 1. The five-axis motion system 1 is used to control the gas-liquid two-phase nozzle 215 to spray ceramic slurry on the conformal substrate 211 or use the conformal scraper 212 to adsorb and dry ceramic powder on the powder outlet bin 213 and lay it on the conformal substrate 211, and scrape the excess powder into the powder inlet bin 214. The present invention innovatively proposes a method for laying ceramic powder by spraying slurry and using a conformal scraper, and then manufactures conformal ceramics through the selective laser melting technology. The traditional selective laser melting technology based on planar roller coating of ceramic powder can only be used to manufacture some planar ceramics and cannot meet the requirements of free-form surface conformal ceramics in special occasions. The present invention successfully overcomes this shortcoming.

[0044] 2. The present invention innovatively proposes a conformal multi-layer ceramic antenna integrated forming device, which includes a five-axis motion system 1, an automatic ceramic powder laying and recycling system 2, a ceramic SLM forming system 3, a ceramic surface conductive pattern printing system 4, and a laser etching system 5. Based on this device, the present invention innovatively uses a method combining ceramic SLM and laser etching to manufacture conformal multi-layer ceramic antennas, breaking the limitation that only LTCC and HTCC methods can be used to manufacture multi-layer ceramic antennas in the past.

[0045] 3. The present invention innovatively proposes a preparation method for silica ceramic slurry to realize the preparation of silica ceramic slurry, breaking the current limitation that the SLM method can only manufacture metals or non-wave-transparent ceramics with high dielectric constants such as alumina and zirconia.

[0046] In summary, the present invention has the advantages of being able to form free-form surface conformal ceramics, meeting the requirements of conformal ceramics in special occasions, using a method combining ceramic SLM and laser etching to manufacture conformal multi-layer ceramic antennas, breaking the limitation that only LTCC and HTCC methods can be used to manufacture multi-layer ceramic antennas in the past, and the proposed preparation method for silica ceramic slurry realizes the SLM forming of silica ceramics. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a schematic diagram of the conformal multi-layer ceramic circuit integrated forming device based on SLM and laser etching according to the embodiment of the present invention.

[0048] Figure 2 is a schematic diagram of the five-axis motion system 1 according to the embodiment of the present invention.

[0049] Figure 2 (a) is an enlarged schematic diagram of the hollow rotary table according to the embodiment of the present invention.

[0050] Figure 3 is a schematic diagram of the automatic ceramic powder laying and recycling system 2 according to the embodiment of the present invention.

[0051] Figure 4 Schematic diagram of a ceramic SLM forming system 3 according to an embodiment of the present invention.

[0052] Figure 5 Schematic diagram of a conductive pattern printing system 4 on a ceramic surface according to an embodiment of the present invention.

[0053] Figure 5 (a) is a schematic diagram of the connection between the piezoelectric nozzle and the nano silver paste storage bucket according to an embodiment of the present invention.

[0054] Figure 6 Schematic diagram of a laser etching system 5 according to an embodiment of the present invention.

[0055] Figure 7 It is a schematic diagram of a control system 6 according to an embodiment of the present invention.

[0056] Figure 8 It is a schematic diagram of the control system relationship of an embodiment of the present invention.

[0057] In the figure, 1 is a five-axis motion system, 11 is an X-axis, 111 is a grating ruler, 12 is a Y-axis, 13 is a Z-axis, 14 is a hollow rotating platform A, 15 is a hollow rotating platform C, 16 is a vertical connecting plate, 17 is a horizontal connecting plate, 18 is a cross adapter plate, 19 is an optical platform, 2 is an automatic ceramic powder spreading and recycling system, 211 is a conformal substrate, 212 is a conformal scraper, 213 is a powder outlet bin, 214 is a powder inlet bin, 215 is a gas-liquid two-phase nozzle, 216 is a slurry barrel, 3 is a ceramic SLM molding system, 31 is a powder bed heating device, 32 is a three-dimensional laser dynamic focusing scanning device, 33 is a laser displacement sensor, 34 is an adapter plate, 35 is a fixed axis of the laser scanning device, 36 is a fixture, 4 is a ceramic surface conductive graphic printing system, 41 is a near-infrared curing device, 42 is a piezoelectric nozzle, 43 is a nano silver paste storage barrel, 5 is a laser etching system, 6 is a control system, 61 is a display panel, 62 is a multilayer ceramic forming button, 63 is a separate process button, 64 is the main frame of the control system panel, and 65 is a single-chip microcomputer. DETAILED DESCRIPTION

[0058] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0059] like Figure 1 As shown, a conformal multilayer ceramic circuit integrated forming device based on SLM and laser etching includes an optical platform 19, two vertical connecting plates 16 are connected to the two sides of the optical platform 19 by bolts, and a horizontal connecting plate 17 is connected between the upper ends of the two vertical connecting plates 16 by bolts to form a gantry structure, and also includes a five-axis motion system 1, an automatic ceramic powder spreading and recycling system 2, a ceramic SLM forming system 3, a ceramic surface conductive pattern printing system 4, a laser etching system 5 and a control system 6;

[0060] The five-axis motion system 1 is arranged on the optical platform 19 and the gantry structure, and as the basic motion system of the whole equipment, it provides motion in the directions of X-axis 11, Y-axis 12 and Z-axis 13 for the automatic ceramic powder spreading and recycling system 2, the ceramic SLM molding system 3, the ceramic surface conductive pattern printing system 4 and the laser etching system 5;

[0061] The automatic ceramic powder spreading and recycling system 2, the ceramic SLM molding system 3, the ceramic surface conductive pattern printing system 4 and the laser etching system 5 are respectively installed on different parts of the five-axis motion system 1 or the optical platform 19;

[0062] Automatic ceramic powder laying and recycling system 2 is used to lay powder or recycle excess powder;

[0063] The ceramic SLM forming system 3 is used to form ceramics from the powder laid by the automatic ceramic powder laying and recycling system 2;

[0064] The ceramic surface conductive pattern printing system 4 is used to add a conductive layer on the ceramic surface prepared by the ceramic SLM molding system 3;

[0065] The laser etching system 5 is used to etch the conductive layer added by the conductive pattern printing system 4 on the ceramic surface to form the pattern required for the antenna circuit;

[0066] The control system 6 is used to control the five-axis motion system 1, the automatic ceramic powder spreading and recycling system 2, the ceramic SLM forming system 3, the ceramic surface conductive pattern printing system 4 and the laser etching system 5 to realize the conformal multilayer ceramic circuit integrated forming process.

[0067] like Figure 2 As shown, the five-axis motion system 1 includes an X-axis 11, a Y-axis 12 and a Z-axis 13, and the X-axis 11, the Y-axis 12 and the Z-axis 13 are all slidably connected with a motion platform, and the motion platform slides along the axial direction;

[0068] The X-axis 11 is fixed to the transverse connecting plate 17 of the gantry structure by bolts, and the Z-axis 13 is fixedly arranged on the motion platform of the X-axis 11. The X-axis 11 and the Z-axis 13 form a cross structure. A grating ruler 111 is fixedly connected to the side of the X-axis 11 by bolts, which is used to measure the position of the Z-axis 13 relative to the X-axis during movement. A cross adapter plate 18 is fixedly connected to the side of the Z-axis 13 away from the X-axis 11;

[0069] The Y-axis 12 is fixed to the optical platform 19 by bolts. The motion platform of the Y-axis 12 is fixedly connected to the hollow rotating platform by bolts. The hollow rotating platform includes a hollow rotating platform C15 and a hollow rotating platform A14. Both the hollow rotating platform C15 and the hollow rotating platform A14 have built-in servo motors to drive the platform to rotate. The fixed end of the hollow rotating platform C15 is fixedly connected to the motion platform of the Y-axis 12, and the rotating end of the hollow rotating platform C15 is connected to the fixed end of the hollow rotating platform A14, see Figure 2 (a);

[0070] The X-axis 11 and the Y-axis 12 are perpendicular to each other and parallel to the optical platform 19, and the Z-axis 13 is perpendicular to the optical platform 19;

[0071] The function of the five-axis motion system 1 is to support the movement of the work platform between different processes, including the three-axis motion of the X-axis 11, Y-axis 12, and Z-axis 13 and the rotational motion of the hollow rotating platform A14 and the hollow rotating platform C15. The X-axis 11, Y-axis 12, and Z-axis 13 are used to control the powder spreading tool to spread powder during ceramic powder spreading. The hollow rotating platform A14 and the hollow rotating platform C15 are used to control the rotational motion of the ceramic antenna forming platform. The forming platform is used for both ceramic SLM manufacturing and conductive layer printing.

[0072] like Figure 3 As shown, the automatic ceramic powder spreading and recycling system 2 includes a ceramic raw material supply device and a ceramic raw material recycling device. The system is used to spread ceramic powder raw materials on a ceramic forming platform. The system mainly uses two powder spreading methods to spread ceramic powder, namely slurry powder spreading and dry powder powder spreading. A gas-liquid two-phase nozzle 215 (this embodiment uses a 304 stainless steel 0.3 aperture fan-shaped siphon nozzle) and a conformal scraper 212 fixed on the cross adapter plate 18, and a conformal substrate 211 fixed to the rotating end of the hollow rotating platform A14. A powder outlet bin 213 and a powder inlet bin 214 are respectively provided on both sides of the conformal substrate 211, and the powder inlet bin 214 is set at a height lower than the conformal substrate 211;

[0073] The gas-liquid two-phase nozzle 215 is connected to the slurry barrel 216. The gas-liquid two-phase nozzle 215 is a component that uses compressed gas to assist liquid in atomization and spraying, and is connected to the threaded hole of the horizontal plate of the cross adapter plate 18 through threads;

[0074] The conformal scraper 212 is fitted with the curved surface of the conformal substrate 211, and a porous sponge strip is attached below the curved surface of the conformal scraper 212, and the porous sponge can effectively absorb powder;

[0075] The conformal substrate 211 is a developable curved surface or a non-developable curved surface substrate made of high-purity graphite with a content of more than 99.9% or 6061 aluminum alloy or silicon dioxide crystal. The conformal substrate 211 of this embodiment is a developable curved surface substrate made of high-purity graphite with a content of more than 99.9%.

[0076] The dry powder spreading method is to use a conformal scraper 212 to evenly absorb a certain amount of powder from the powder outlet bin 213, and then move along the surface of the conformal substrate 211. The powder on the conformal scraper 212 is evenly adhered to the surface of the conformal substrate 211, and the excess ceramic powder is scraped back into the powder bin 214. The slurry spreading method is to use a gas-liquid two-phase nozzle 215 to spray water-based ceramic slurry on the conformal substrate 211. The water-based ceramic slurry is stored in a slurry barrel 216. The gas-liquid two-phase nozzle 215 is a siphon nozzle. While the X-axis 11 drives the Z-axis 13 to move left and right, the ceramic slurry stored in the slurry barrel 216 is automatically extracted and transported to the liquid outlet of the gas-liquid two-phase nozzle 215 through a hose for uniform atomization and spraying. The core component of the dry powder spreading method is the conformal scraper 212. The shape of the conformal scraper 212 is designed according to the required conformal ceramic shape, and the edge of the scraper is tangent to the surface of the conformal substrate 211. The conformal scraper 212 moves along the surface of the conformal substrate 211. The conformal scraper 212 is at a certain distance from the conformal substrate 211. The distance is the thickness of the ceramic powder layer, generally between 10 microns and 100 microns. The conformal scraper 212 evenly spreads the dry ceramic powder from the powder outlet 213 on the conformal substrate 211, and scrapes the excess ceramic powder back into the powder bin 214. The core component of the slurry powder spreading method is the gas-liquid two-phase nozzle 215. The two sides of the gas-liquid two-phase nozzle are respectively a liquid interface and a gas interface. The nozzle uses high-speed high-pressure gas to atomize the slurry and then sprays it out from a nozzle with an aperture of 0.1-0.5mm.

[0077] like Figure 4 As shown, the ceramic SLM molding system 3 includes a powder bed heating device 31 (the present embodiment adopts a copper block heating device with a maximum temperature of 500 degrees Celsius), a three-dimensional laser dynamic focusing scanning device 32 (the present embodiment adopts a 500-format model, and the minimum focusing spot is 16 microns), and a laser displacement sensor 33 (the present embodiment adopts a 0-10mm range NPN type);

[0078] The powder bed heating device 31 is disposed inside the conformal substrate 211;

[0079] The three-dimensional laser dynamic focusing scanning device 32 is arranged above the Y-axis 12, and is connected to the moving platform of the laser scanning device fixed axis 35 through the adapter plate 34. The moving platform of the laser scanning device fixed axis 35 is slidably connected to the laser scanning device fixed axis 35, and slides along the axial direction of the laser scanning device fixed axis 35. The laser scanning device fixed axis 35 is vertically fixed on the optical platform 19.

[0080] The laser displacement sensor 33 is fixed to the bottom end of the cross adapter plate 18 by a clamp 36;

[0081] Among them, the powder bed heating device 31 is used to evaporate the solvent in the ceramic slurry and reduce the temperature change gradient of the ceramic during the SLM process. The purpose is to reduce the cracks in the ceramic; the three-dimensional laser dynamic focusing scanning device 32 in this equipment needs to be connected to a laser for use. According to the absorption rate of the ceramic material to the light wave, a 1064nm-200W fiber laser, a 1060nm-200W carbon dioxide laser or a 1064nm-200WNd:YAG laser can be used respectively. In this embodiment, a 1064nm-200W fiber laser is used; the functions of the three-dimensional laser dynamic focusing scanning device 32 are mainly two aspects, namely, real-time focusing of the laser on a conformal surface and motion scanning of the laser according to a set path. The laser displacement sensor 33 is used to measure the thickness of the powder layer and the thickness of each layer of ceramic in the powder laying process. The scanning device adapter plate 34 is used to connect the three-dimensional laser dynamic focusing Scanning device 32 and laser scanning device fixed axis 35; the heating temperature of the substrate heating device 31 in the ceramic SLM molding system 3 is up to 400 degrees Celsius, and the rectangular heating copper block is placed in the middle of the conformal substrate 211, and the heat is transferred to the surface of the conformal substrate 211 by heat conduction, so as to achieve the purpose of heating the substrate and evaporating the slurry solvent; the laser scanning device fixed axis 35 is installed on the corresponding position of the optical platform 19 by bolts, and the scanning device adapter plate 34 is connected to the threaded hole of the sliding platform of the laser scanning device fixed axis 35 by bolts, and the three-dimensional laser dynamic scanning device 32 is fixed by the corresponding hole position on the scanning device adapter plate 34, and the laser displacement sensor 33 is placed at the corresponding position of the fixture 36, and is fixed to the corresponding hole position on the vertical plate of the cross adapter plate 18 by bolt connection, and the distance between the laser light outlet on the three-dimensional laser dynamic scanning device 32 and the conformal substrate 211 is determined by the focusing characteristics of the galvanometer.

[0082] like Figure 5 As shown, the ceramic surface conductive pattern printing system 4 includes a near-infrared curing device 41, a piezoelectric nozzle 42, and a nano silver paste storage barrel 43;

[0083] The near-infrared curing device 41 uses a wavelength of 1064 nm and a power of 1500 W, is disposed above the Y axis 12, and is fixed on the optical platform 19 by a bracket;

[0084] The piezoelectric nozzle 42 is fixed to the bottom end of the cross adapter plate 18 by a clamp 36;

[0085] The nano silver paste storage barrel 43 is the same as the paste barrel 216, placed above the optical platform 19, and connected to the piezoelectric nozzle 42 through a hose, see Figure 5 (a).

[0086] The main function of this system is to add conductive layers to the surface of ceramics that have been manufactured by the ceramic SLM molding system 3, so as to facilitate the subsequent conductive pattern etching process. The ceramic surface conductive layer printing system 4 adopts a droplet injection method, and a piezoelectric nozzle 42 is used to spray a nanosilver solution onto the ceramic on the surface of the conformal substrate 211. The five parts of the X-axis 11, the Y-axis 12, the Z-axis 13, the hollow rotating platform A14, and the hollow rotating platform C15 are linked to enable the piezoelectric nozzle 42 to perform spray printing along the curved path along the conformal substrate 211. The substrate heating device 31 sprays the nanosilver metal solution sprayed by the piezoelectric nozzle 42 on the conformal substrate 211. After the solvent evaporates, it is sintered and cured by the near-infrared curing device 41 to form a conductive layer. The near-infrared curing device 41 is fixed to the corresponding position of the optical platform 19 by bolts. The piezoelectric nozzle 42 has fixed holes that can be fixed on it. Figure 5 At the fixture in the.

[0087] like Figure 6 As shown, the laser etching system 5 is composed of some equipment of the ceramic SLM molding system 3, including a powder bed heating device 31 and a three-dimensional laser dynamic focusing scanning device 32.

[0088] The main function of the laser etching system 5 is to etch the antenna circuit pattern on the ceramic with the conductive metal layer printed on the surface, and use the three-dimensional laser dynamic focusing scanning device 32 to control the movement trajectory of the laser, and etch away the excess conductive metal on the ceramic according to the antenna path pattern. The laser etching system 5 is used based on the ceramic surface conductive pattern printing system 4 after completing the conductive layer printing process. The most important mechanical equipment structure of the system is the same as the ceramic SLM molding system 3. The required antenna or circuit conductive pattern is set on the host computer through the three-dimensional laser dynamic scanning device 32, and then the three-dimensional laser dynamic scanning device 32 is used to control the path of the laser movement to etch away the unnecessary part of the conductive layer above the conformal substrate 211, and finally obtain the corresponding antenna or circuit pattern.

[0089] like Figure 7As shown, the control system 6 is composed of a display panel 61, a multilayer ceramic forming button 62, a separate process button 63, a control system panel main frame 64, and a single-chip computer 65. In this embodiment, the display panel 61 adopts Siemens KTP700, and the single-chip computer 65 adopts STM32. The display panel 61 is used to detect the motion state of the system in real time, including the forming progress, the motion state of the X-axis 11, the Y-axis 12, the Z-axis 13 and the hollow rotating platform A14, and the hollow rotating platform C15. The multilayer ceramic forming button 62 is used to start the entire process, control the X-axis 11, the Y-axis 12, the Z-axis 13, the hollow rotating platform A14, the hollow rotating platform C15, the gas-liquid two-phase nozzle 215, the conformal scraper 212, the piezoelectric nozzle 42, the near-infrared curing device 41, and the three-dimensional laser dynamic focusing scanning device 32 to respectively perform ceramic slurry spraying, dry ceramic powder laying, ceramic forming, and conductive layer forming processes. The individual step buttons 63 are divided into four buttons: slurry injection, conformal scraper, ceramic forming, and conductive layer forming. Each button controls the corresponding axis, rotating platform, and other components to implement the corresponding process. The control system panel main frame 64 is used to connect the display panel 61, the multilayer ceramic forming button 62, and the individual process button 63. The three parts are installed in the corresponding positions of the control system panel main frame 64 by inlay. The control pins corresponding to the components in the multilayer ceramic forming button 62, the individual process button 63, the five-axis motion system 1, the automatic ceramic powder laying and recycling system 2, the ceramic SLM forming system 3, the ceramic surface conductive pattern printing system 4, and the laser etching system 5 are respectively connected to the pins of the single-chip microcomputer 65, so that the single-chip microcomputer 65 can control the system in the equipment through buttons to complete the corresponding process. For specific control relationships, refer to Figure 8 .

[0090] A conformal multilayer ceramic circuit integrated forming method comprises the following steps:

[0091] Step 1: Control the gas-liquid two-phase nozzle 215 to move along the X-axis 11 at a speed of 50 mm / s through the control system 6, and spray the ceramic slurry on the conformal substrate (211) at a spray flow rate of 25 L / h;

[0092] Step 2: Prepare ceramics through the SLM forming system 3: Use the powder bed heating device 31 to heat the ceramic slurry or ceramic powder on the conformal substrate 211 until the multilayer ceramic circuit is completed, the heating temperature is 400°C, and the control system 6 controls the conformal substrate 211 to move below the three-dimensional laser dynamic focusing scanning device 32, and then use the three-dimensional laser dynamic focusing scanning device 32 to scan and melt the ceramic material on the conformal substrate 211 to form ceramics, and use the laser displacement sensor 33 to measure the thickness of the ceramic layer. If the required layer thickness is reached, the ceramic forming process is stopped and step 3 is performed;

[0093] Step 3: The piezoelectric nozzle 42 and the conformal substrate 211 are controlled to move by the control system 6, and the nanosilver paste (the nanosilver paste is water-based, has a particle size of 10 nanometers, and is purchased commercially) is sprayed on the ceramic surface of the conformal substrate 211 by the piezoelectric nozzle 42, and then the conformal substrate 211 is moved to the top of the near-infrared curing device 41 for sintering to form a conductive layer;

[0094] Step 4: Control the conformal substrate 211 to move to below the three-dimensional laser dynamic focusing scanning device 32 through the control system 6, and use the laser to etch the required circuit pattern;

[0095] Step 5: After the circuit pattern is etched, return to step 1 and perform a new round of forming process to finally complete the forming of the multilayer ceramic circuit.

[0096] The ceramic slurry described in step 1 is silicon dioxide, and its preparation method comprises:

[0097] Step 1.1: Mix 10 μm silica powder and 20 nm carbon black powder in a mass ratio of 20:1.

[0098] Step 1.2: Add 5 times the mass of deionized water to the mixture obtained in step 1.1;

[0099] Step 1.3: After the mixture after adding deionized water in step 1.2 is initially stirred, it is stirred at a speed of 3000 revolutions per minute for 60 minutes using a stirrer to finally prepare a silica ceramic slurry.

[0100] In summary, this embodiment proves that the present invention is capable of forming free-form surface conformal ceramics to meet the needs of conformal ceramics in special occasions, and utilizes a method combining a ceramic SLM method and a laser etching method to manufacture conformal multilayer ceramic antennas, breaking the limitation that multilayer ceramic antennas can only be manufactured using LTCC and HTCC methods in the past.

Claims

1. A conformal multilayer ceramic circuit integrated forming device based on SLM and laser etching, comprising an optical platform (19), and a gantry structure configured with the optical platform (19), characterized in that: It also includes a five-axis motion system (1), an automatic ceramic powder spreading and recycling system (2), a ceramic SLM molding system (3), a ceramic surface conductive pattern printing system (4), a laser etching system (5) and a control system (6); The five-axis motion system (1) is arranged on the optical platform (19) and the gantry structure, and serves as the basic motion system of the entire device, providing motion in the directions of the X-axis (11), the Y-axis (12) and the Z-axis (13) for the automatic ceramic powder spreading and recycling system (2), the ceramic SLM molding system (3), the ceramic surface conductive pattern printing system (4), and the laser etching system (5); Automatic ceramic powder laying and recycling system (2) is used to lay powder or recycle excess powder; The ceramic SLM forming system (3) is used to form ceramics from the powder laid by the automatic ceramic powder laying and recycling system (2); The ceramic surface conductive pattern printing system (4) is used to add a conductive layer on the ceramic surface prepared by the ceramic SLM molding system (3); The laser etching system (5) is used to etch the conductive layer added by the conductive pattern printing system (4) on the ceramic surface to form a pattern required for the antenna circuit; The control system (6) is used to control a five-axis motion system (1), an automatic ceramic powder spreading and recycling system (2), a ceramic SLM molding system (3), a ceramic surface conductive pattern printing system (4) and a laser etching system (5); and realizes a conformal multilayer ceramic circuit integrated molding process.

2. The conformal multilayer ceramic circuit integrated forming device based on SLM and laser etching according to claim 1, characterized in that: The five-axis motion system (1) comprises an X-axis (11), a Y-axis (12) and a Z-axis (13), and the X-axis (11), the Y-axis (12) and the Z-axis (13) are all slidably connected with a motion platform, and the motion platform slides along the axial direction; The X-axis (11) is fixed on a transverse connecting plate (17) of the gantry structure; a Z-axis (13) is fixedly arranged on a moving platform of the X-axis (11); the X-axis (11) and the Z-axis (13) form a cross structure; a grating ruler (111) is fixedly connected to a side of the X-axis (11); and a cross adapter plate (18) is fixedly connected to a side of the Z-axis (13) away from the X-axis (11); The Y-axis (12) is fixed on the optical platform (19), and the moving platform of the Y-axis (12) is fixedly connected to the hollow rotating platform, the hollow rotating platform includes a hollow rotating platform C (15) and a hollow rotating platform A (14), and both the hollow rotating platform C (15) and the hollow rotating platform A (14) are built-in servo motors for driving the platforms to rotate, the fixed end of the hollow rotating platform C (15) is fixedly connected to the moving platform of the Y-axis (12), and the rotating end of the hollow rotating platform C (15) is connected to the fixed end of the hollow rotating platform A (14); The X-axis (11) and the Y-axis (12) are perpendicular to each other and parallel to the optical platform (19), and the Z-axis (13) is perpendicular to the optical platform (19).

3. The conformal multilayer ceramic circuit integrated forming device based on SLM and laser etching according to claim 2, characterized in that: The automatic ceramic powder spreading and recycling system (2) comprises a gas-liquid two-phase nozzle (215) and a conformal scraper (212) fixed on a cross transfer plate (18), and a conformal substrate (211) fixed on the rotating end of a hollow rotating platform A (14), and a powder outlet bin (213) and a powder inlet bin (214) are respectively arranged on both sides of the conformal substrate (211).

4. The conformal multilayer ceramic circuit integrated forming device based on SLM and laser etching according to claim 3, characterized in that: The powder inlet bin (214) is arranged at a height lower than the conformal substrate (211); The gas-liquid two-phase nozzle (215) is connected to the slurry barrel (216); The conformal scraper (212) is in contact with the curved surface of the conformal substrate (211), and a porous sponge strip is attached below the curved surface of the conformal scraper (212); The conformal substrate (211) is a curved substrate with an expandable curved surface or a non-expandable curved surface made of high-purity graphite with a content of more than 99.9% or 6061 aluminum alloy or silicon dioxide crystal.

5. The conformal multilayer ceramic circuit integrated forming device based on SLM and laser etching according to claim 2, characterized in that: The ceramic SLM molding system (3) comprises a powder bed heating device (31), a three-dimensional laser dynamic focusing scanning device (32), and a laser displacement sensor (33); The powder bed heating device (31) is arranged inside the conformal substrate (211); The three-dimensional laser dynamic focusing scanning device (32) is arranged above the Y axis (12) and is connected to a moving platform of a laser scanning device fixed axis (35) through an adapter plate (34); the moving platform of the laser scanning device fixed axis (35) is slidably connected to the laser scanning device fixed axis (35) and slides along the axial direction of the laser scanning device fixed axis (35); the laser scanning device fixed axis (35) is vertically fixed on the optical platform (19); The laser displacement sensor (33) is fixed to the bottom end of the cross adapter plate (18).

6. The conformal multilayer ceramic circuit integrated forming device based on SLM and laser etching according to claim 2, characterized in that: The ceramic surface conductive pattern printing system (4) comprises a near-infrared curing device (41), a piezoelectric nozzle (42), and a nano silver paste storage bucket (43); The near-infrared curing device (41) is arranged above the Y-axis (12) and fixed on the optical platform (19); The piezoelectric nozzle (42) is fixed to the bottom end of the cross adapter plate (18); The nano silver paste storage barrel (43) is placed above the optical platform (19) and is connected to the piezoelectric nozzle (42).

7. The conformal multilayer ceramic circuit integrated forming device based on SLM and laser etching according to claim 5, characterized in that: The laser etching system (5) is composed of some equipment of the ceramic SLM molding system (3), including a powder bed heating device (31) and a three-dimensional laser dynamic focusing scanning device (32); The powder bed heating device (31) is arranged inside the conformal substrate (211); The three-dimensional laser dynamic focusing scanning device (32) is arranged above the Y-axis (12) and is connected to a moving platform of a fixed axis (35) of the laser scanning device via an adapter plate (34); the moving platform of the fixed axis (35) of the laser scanning device is slidably connected to the fixed axis (35) of the laser scanning device and slides along the axial direction of the fixed axis (35) of the laser scanning device; the fixed axis (35) of the laser scanning device is vertically fixed on the optical platform (19).

8. The conformal multilayer ceramic circuit integrated forming device based on SLM and laser etching according to claim 7, characterized in that: The control system (6) is composed of a display panel (61), a multilayer ceramic forming button (62), a separate process button (63), a control system panel main frame (64), and a single chip microcomputer (65). The display panel (61), the multilayer ceramic forming button (62), the separate process button (63), and the single chip microcomputer (65) are installed on corresponding positions of the control system panel main frame 64 by means of inlay. The control pins corresponding to the components in the multilayer ceramic forming button (62), the separate process button (63), the five-axis motion system (1), the automatic ceramic powder spreading and recycling system (2), the ceramic SLM forming system (3), the ceramic surface conductive pattern printing system (4), and the laser etching system (5) are respectively connected to the pins of the single chip microcomputer (65), so that the single chip microcomputer (65) controls the system in the device through buttons to complete the corresponding process.

9. A method for integrated conformal multilayer ceramic circuit forming based on the device according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Control the gas-liquid two-phase nozzle (215) to move along the X-axis (11) at a speed of 40 mm / s to 60 mm / s by a control system (6), and spray the ceramic slurry on the conformal substrate (211) at a spray flow rate of 20-25 L / h, or use a conformal scraper (212) to adsorb dry silicon dioxide ceramic powder on a powder outlet bin (213), and lay 50 to 100 microns of dry silicon dioxide ceramic powder on the conformal substrate (211); Step 2: preparing ceramics through a ceramic SLM forming system (3): using a powder bed heating device (31) to heat the ceramic slurry or ceramic powder on the conformal substrate (211) until a multilayer ceramic circuit is completed, the heating temperature is 300-500°C, and the control system (6) controls the conformal substrate (211) to move below the three-dimensional laser dynamic focusing scanning device (32), and then uses the three-dimensional laser dynamic focusing scanning device (32) to scan and melt the ceramic material on the conformal substrate (211) to form ceramics, and uses a laser displacement sensor (33) to measure the thickness of the ceramic layer. If the required layer thickness is reached, the ceramic forming process is stopped and step 3 is performed; Step 3: Controlling the movement of the piezoelectric nozzle (42) and the conformal substrate (211) by means of a control system (6), spraying nano silver paste on the ceramic surface of the conformal substrate (211) by means of the piezoelectric nozzle (42), and then moving the conformal substrate (211) above the near-infrared curing device (41) for sintering to form a conductive layer; Step 4: Controlling the conformal substrate (211) to move to the bottom of the three-dimensional laser dynamic focusing scanning device (32) through the control system (6), and etching the required circuit pattern using laser; Step 5: After the circuit pattern is etched, return to step 1 and perform a new round of forming process to finally complete the forming of the multilayer ceramic circuit.

10. The method for integrated forming of a conformal multilayer ceramic circuit according to claim 9, characterized in that: The ceramic slurry described in step 1 is silicon dioxide, and its preparation method comprises: Step 1.1: Mixing silicon dioxide powder with a particle size of 10 micrometers to 40 micrometers and carbon black powder with a particle size of 20 nanometers to 50 nanometers in a mass ratio of (20-40):1; Step 1.2: Add 5 to 10 times the mass of deionized water to the mixture obtained in step 1.1; Step 1.3: After the mixture after adding deionized water in step 1.2 is initially stirred, the mixture is stirred at a speed of 3000 to 6000 revolutions per minute using a stirrer for 30 to 60 minutes to finally prepare a silica ceramic slurry.

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