Method for preparing an htcp ceramic green body with open cavity structure

Abstract

This invention provides a method for preparing an HTCC ceramic green body with an open cavity structure, comprising the following steps: pre-pressing and shaping a first green body to form a first layer, the first layer having multiple metal terminals; pre-pressing and shaping a second green body to form a second layer, the second layer having multiple openings, each opening corresponding to a multiple metal terminal; bonding the first layer and the second layer together, aligning each opening with its corresponding metal terminal; laminating the first layer and the second layer to form an HTCC ceramic green body, wherein the multiple openings and the first layer form an open cavity structure, and the metal terminals are exposed through the openings; the pressure during the lamination process is less than the pressure of at least one of the first green body and the second green body during pre-pressing and shaping.

Description

Technical Field

[0001] This invention relates to the field of high-temperature co-fired ceramics (HTCC) technology, specifically to a method for preparing HTCC ceramic green bodies with an open cavity structure. Background Technology

[0002] High-temperature co-fired ceramics (HTCCs) possess characteristics such as high temperature resistance, high mechanical strength, stable thermal conductivity, and excellent insulation properties, and are widely used in high-end electronic components such as electrostatic chucks, packaging bases, and ceramic heating devices. In the fabrication of these electronic components, the open-cavity structure on the ceramic surface is crucial. The inner bottom of the open-cavity structure typically requires the installation of metal terminals, heating circuits, or conductive electrodes. These circuits are pre-formed through screen printing on green ceramic sheets and cannot be fabricated using secondary methods such as machining or laser processing after high-temperature sintering. Furthermore, the opening process can easily damage the circuitry at the bottom of the cavity. Therefore, the open-cavity structure must be formed in one step during the ceramic green body lamination stage. The ceramic green body cavity must also maintain stable shape (no collapse, no deformation), high dimensional accuracy, and no internal defects to ensure that the electrical, thermal, and mechanical properties of the subsequently sintered ceramic product meet the required standards. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art, and provides a method for preparing HTCC ceramic green bodies with open cavity structure. By prefabricating separately and then merging them, the cavity shape can be kept stable, the dimensional accuracy is high, and there are no internal defects.

[0004] In a first aspect, the present invention provides a method for preparing an HTCC ceramic green body with an open cavity structure, comprising the following steps:

[0005] The first blank is pre-pressed and shaped to form the first layer, which has multiple metal terminals;

[0006] The second blank is pre-pressed and shaped to form a second layer. The second layer has multiple openings, and each of the multiple openings corresponds to a multiple of the metal terminals.

[0007] The first layer and the second layer are bonded together, and each of the openings is aligned with the corresponding metal terminal;

[0008] The first layer and the second layer are laminated to form the HTCC ceramic green body, and the plurality of openings form the cavity structure with the first layer, and the metal terminals are exposed through the openings;

[0009] The pressure during the lamination process is less than the pressure of at least one of the first and second blanks during pre-pressing and shaping.

[0010] In some embodiments, the step of pre-pressing and shaping the first blank to form the first layer includes:

[0011] Multiple first blanks were obtained;

[0012] Conductive holes are formed on at least one of the first blanks, and the conductive holes are filled with metal paste to electrically interconnect the interlayers within the first blanks.

[0013] The metal terminal is formed by processing the location of the conductive hole.

[0014] Multiple first blanks are aligned and stacked to form the first blank body;

[0015] The first blank is pre-pressed and shaped to form the first block layer.

[0016] In some embodiments, the step of pre-pressing and shaping the second blank to form the second layer includes:

[0017] Multiple second blanks are obtained, and the second blanks have the same shape and size as the first blank.

[0018] Drill holes in each of the second blanks to obtain multiple sub-openings;

[0019] Multiple second blanks are stacked in alignment based on the sub-openings to form a second blank body; wherein the multiple sub-openings located on each of the second blanks are aligned and connected to form the openings;

[0020] The second blank is pre-pressed and shaped to form the second layer.

[0021] In some embodiments, it also includes:

[0022] Perforated edge regions of each of the first blanks are drilled to obtain multiple first positioning holes; the multiple first blanks are aligned and stacked based on the first positioning holes; and...

[0023] The edge areas of each of the second blanks are punched to obtain multiple second positioning holes, and the multiple second blanks are stacked in alignment based on the second positioning holes; the second positioning holes correspond one-to-one with the first positioning holes.

[0024] In some embodiments, the step of bonding the first block layer and the second block layer includes:

[0025] A composite adhesive is applied to the first layer, and after a drying process, the second layer is bonded to the first layer. The first positioning hole and the second positioning hole are aligned, and the opening is aligned with the metal terminal.

[0026] The first and second layers after bonding are laminated.

[0027] In some embodiments, the drying conditions of the composite adhesive are: a temperature range of 25°C to 80°C and a drying time range of 5 min to 60 min.

[0028] In some embodiments, the method further includes a step of preparing the composite adhesive;

[0029] The preparation steps of the composite adhesive include:

[0030] Heat water to 40℃~80℃, add polyvinyl alcohol and stir until completely dissolved;

[0031] Cool the temperature to 30℃~50℃, add polyethylene glycol and triacetin, and stir until well mixed;

[0032] Add octylphenol polyoxyethylene ether and borax, and continue stirring;

[0033] After cooling to room temperature and allowing to stand to defoam, the composite adhesive is obtained.

[0034] In some embodiments, the pre-pressing and shaping process conditions are: temperature range 40℃~90℃, pressure range 10MPa~20MPa, and holding time 2min~3min; the low-pressure lamination conditions are: temperature range 25℃~60℃, pressure range 1MPa~5MPa, and holding time 1min~2min.

[0035] In some embodiments, the HTCC ceramic green body includes a first surface and a second surface disposed opposite to each other along its thickness direction; the preparation method further includes:

[0036] A layer of release film is laid on both the first and second surfaces, and then placed between two laminates to form an intermediate product. After vacuum sealing with a packaging bag, it is pressed.

[0037] After pressing, remove the packaging bag, pressure plate, and release film in sequence;

[0038] The HTCC ceramic green body after pressing is sintered.

[0039] In some embodiments, the metal terminal is matched with the sintering linear shrinkage rate of the HTCC ceramic green body.

[0040] In some embodiments, the thickness of the isolation membrane is 30 μm to 200 μm; the thickness of the pressure plate is 0.5 mm to 2 mm, and its surface roughness is 0.01 μm to 0.03 μm.

[0041] The present invention has the following beneficial effects:

[0042] The present invention provides a method for preparing HTCC ceramic green bodies with open-cavity structures. This involves preparing a first layer and a second layer separately, then bonding them together and laminating the entire structure to form the HTCC ceramic green body. During the preparation of the first layer, multiple metal terminals are fabricated. During the preparation of the second layer, multiple openings are fabricated on the second layer, each corresponding to one of the metal terminals. When the first and second layers are bonded together, the openings and the first layer form an open-cavity structure, through which the metal terminals are exposed for subsequent processing. This preparation method maintains the stability of the cavity shape (no collapse, no deformation), achieves high forming accuracy, and eliminates internal defects. Attached Figure Description

[0043] Figure 1 This is an exploded view of an HTCC ceramic green body with an open cavity structure provided in the first embodiment of the present invention.

[0044] Figure 2 This is an exploded view of an HTCC ceramic green body with an open cavity structure provided in the second embodiment of the present invention. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0046] It should be noted that although functional modules are divided in the device schematic diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than the module division in the device or the order in the flowchart. In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features. Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "setting," and "arrangement," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0047] Among the related technologies, the main methods for preparing HTCC ceramic green bodies with open cavity structures are the elastic pad support method and the sacrificial material filling method. However, the following defects of the two methods make it difficult to simultaneously meet the requirements of no cavity collapse, no deformation, no residual carbon pollution, and stable and controllable process, which has become a bottleneck for improving the precision and large-scale production of HTCC ceramic products with open cavity structures.

[0048] The elastic pad support method involves pre-placing shape-matched elastic pads, such as silicone pads, at the opening locations of the green ceramic sheet to support the cavity walls and prevent collapse during lamination. However, in actual production, the dimensional accuracy and hardness parameters of the elastic pads vary considerably, making precise matching with the cavity structure difficult. Furthermore, different batches of elastic pads may exhibit significant differences in material uniformity and resilience. Simultaneously, elastic pads are prone to aging, deformation, and wear under repeated high-temperature and high-pressure lamination conditions, making it difficult to accurately estimate their performance stability and service life, and significantly complicating process standardization control. In addition, during lamination, issues such as uneven support force, dimensional deviations, or hardness mismatches in the elastic pads can directly lead to edge collapse, internal delamination, and cavity bottom deformation in the green ceramic sheet. This, in turn, can cause broken printed metal circuits, DC electrode misalignment, and uneven heater electrode distribution, ultimately resulting in reduced voltage resistance, uneven heat conduction, poor adsorption force, and poor temperature uniformity in the finished ceramic product, significantly lowering product yield.

[0049] The sacrificial material filling method involves filling the cavity area with a sacrificial agent containing carbon-containing materials or organic polymers, co-laminating it with a green ceramic sheet, and then sintering it. The sacrificial agent burns off at high temperatures to form the cavity structure. While this method can be used for closed-cavity fabrication, its application in HTCC cavity molding has significant limitations. Specifically, the burn-off of the carbon-containing sacrificial agent depends on oxidation in an oxidizing atmosphere. However, high-end HTCC products often require sintering in a H2 / N2 reducing atmosphere to ensure the performance of the metal electrodes and the density of the ceramic. Under a reducing atmosphere, carbon residue cannot be completely removed due to the lack of oxidation conditions, easily remaining in the ceramic cavity and internal pores, forming residual carbon contamination. This leads to deterioration of the product's insulation performance, increased leakage risk, and seriously affects the operational stability of key components such as electrostatic chucks. Furthermore, the filling and leveling processes for the sacrificial agent are complex, and improper operation can easily contaminate the printed circuit lines, further increasing the difficulty of production control.

[0050] To address the problems of the aforementioned molding methods, this invention aims to provide a method for preparing HTCC ceramic green bodies with an open cavity structure. This method employs a split-prefabrication and reassembly approach, separating the HTCC ceramic green body into a first layer and a second layer. After the first and second layers are pre-shaped separately, they are then merged. This process forms a complete ceramic green body while simultaneously creating an open cavity structure from the openings in the first and second layers. This method fundamentally avoids the problems of green body cavity deformation and residual carbon that occur in related technologies, improving the molding accuracy of the open cavity structure and the yield of ceramic products.

[0051] like Figure 1 and Figure 2 As shown, the HTCC ceramic green body with an open cavity structure provided in this embodiment of the invention includes: a first layer 1 and a second layer 2. The first layer 1 has a plurality of metal terminals 4, and the second layer 2 has a plurality of openings 3, with each opening 3 corresponding to one of the plurality of metal terminals 4. The second layer 2 is disposed above the first layer 1. The side of the first layer 1 near the second layer 2 is coated with a composite adhesive 5. After the second layer 2 and the first layer 1 are bonded together by the composite adhesive 5, the plurality of openings 3 and the first layer 1 form an open cavity structure, and the metal terminals 4 are exposed through the openings 3.

[0052] The first layer 1 is formed by pre-pressing and shaping a first blank, which includes a plurality of first blank pieces 11 stacked sequentially. The second layer 2 is formed by pre-pressing and shaping a second blank, which includes a plurality of second blank pieces 21 stacked sequentially.

[0053] The first embodiment of the present invention provides a method for preparing the above-mentioned HTCC ceramic green body with open cavity structure, comprising the following steps:

[0054] S1. The first blank is pre-pressed and shaped to form the first layer, which has multiple metal terminals.

[0055] S2. The second blank is pre-pressed and shaped to form a second layer. The second layer has multiple openings, and each opening corresponds to a metal terminal.

[0056] S3. Attach the first layer and the second layer together, and align each opening with the corresponding metal terminal.

[0057] S4. The first and second layers are laminated to form an HTCC ceramic green body, with multiple openings forming an open cavity structure with the first layer, through which metal terminals are exposed. The pressure during the lamination process is less than the pressure applied to at least one of the first and second green bodies during pre-pressing and shaping.

[0058] In this embodiment, the first and second layers are prepared separately, then bonded together and laminated to form an HTCC ceramic green body. During the preparation of the first layer, multiple metal terminals are fabricated on it; during the preparation of the second layer, multiple openings are fabricated on it, each corresponding to one of the metal terminals. When the first and second layers are bonded together, the openings and the first layer form an open cavity structure. This cavity structure requires no additional support material, and the metal terminals are exposed through the openings for subsequent processing. This preparation method maintains the stability of the cavity shape (no collapse, no deformation), achieves high forming accuracy, and is free of internal defects.

[0059] In some specific embodiments of the present invention, step S1, which involves pre-pressing and shaping the first blank to form the first layer, includes:

[0060] S11, Obtain multiple first blanks.

[0061] S12. Form conductive holes on at least one first blank and fill the conductive holes with metal paste to electrically interconnect the layers within the first blank.

[0062] S13. Process the conductive hole to form a metal terminal.

[0063] S14. Align and stack multiple first blanks to form a first blank.

[0064] S15. The first blank is pre-pressed and shaped to form the first layer.

[0065] In this embodiment, the raw material for preparing the first blank is HTCC rolled elongated ceramic sheet, which is a flexible ceramic blank that has not undergone high-temperature sintering and has the characteristics of being cut, punched, and stacked for shaping.

[0066] In step S11, for example, HTCC roll-shaped cast ceramic tiles with a thickness of 0.3mm to 1mm are placed into a precision cutting machine and cut into multiple first blanks. The shape of the first blanks can be, for example, a regular polygon, and the size can be, for example, 450mm × 450mm. Then, defective blanks with broken edges or uneven thickness are removed from the multiple first blanks, and blanks with regular size and flat surface are retained.

[0067] In step S12, for example, the first blank is fixed on the worktable of a laser drilling machine, and the laser drilling machine is used to drill holes in the non-edge area of ​​the first blank to obtain multiple conductive holes. Laser processing involves no mechanical contact and no stress deformation, which can ensure that the conductive holes have regular contours, smooth inner walls, and high dimensional accuracy, avoiding problems such as edge chipping, deformation, and poor flatness of the conductive holes caused by mechanical drilling. The diameter of the conductive holes can be, for example, 0.2mm to 0.8mm. Afterwards, a metal slurry is filled into the conductive holes using an injection filling machine. The injection filling machine adopts the principle of high-pressure micro-injection filling, which can achieve quantitative and precise injection of metal slurry into the conductive holes, and has the characteristics of high filling density, no voids, no broken holes, and no slurry overflow on the surface.

[0068] After filling, the surface of the first blank is leveled to remove excess metal paste and ensure that the surface of the first blank is flat overall.

[0069] It should be noted that when there are multiple first blanks used to prepare the first layer, such as five, conductive holes are formed on at least one of the first blanks. For example, conductive holes are formed by drilling holes in two of the first blanks. Figure 2 As shown, the positions of the conductive holes at corresponding locations on the two first blanks do not need to be exactly the same, but it is necessary to ensure that when the two blanks are aligned and stacked, the conductive holes at corresponding locations on the two blanks at least partially overlap, so that the metal paste in the conductive holes can at least partially contact each other. After high-temperature sintering, the metal paste can form a dense and stable conductive path, realizing the electrical connection between the two first blanks.

[0070] In step S13, for example, the first blank after paste filling is placed in a screen printing machine, and the positions where the metal paste is filled are screen printed to form metal terminals. These metal terminals match the sintering linear shrinkage rate of the HTCC ceramic green body. Furthermore, circuitry, reference markings, and surface-modified coatings are printed as needed on other positions on the first blank, thereby improving the surface condition of the first blank and enhancing the bonding reliability of subsequent processes.

[0071] In step S14, for example, an automatic stacking machine is used to precisely align and stack multiple first blanks that have completed screen printing, ensuring that the first blanks in each layer are completely overlapped, without offset, wrinkles, or foreign matter inclusions, to form a first blank. The number of stacked layers, i.e., the number of first blanks, such as 2 to 10, can be adjusted according to the thickness and strength requirements of the first layer.

[0072] It should be noted that during the stacking process, the first blank containing the metal terminal corresponding to the opening should be placed on the top layer to facilitate subsequent processing.

[0073] The reference for aligning and stacking multiple first blanks can be, for example, in step S12, fixing the first blank on the worktable of a CNC punching machine and using the CNC punching machine to punch holes in the edge area of ​​the first blank to obtain multiple first positioning holes.

[0074] It should be noted that all the first blanks used to prepare the first layer must be punched at the same position using a CNC punching machine to obtain multiple first positioning holes. The multiple first blanks are then aligned and stacked based on these first positioning holes. Specifically, the first positioning holes at corresponding positions on each first blank are aligned.

[0075] The CNC punching machine has high punching position accuracy and good consistency, which can ensure the alignment accuracy of the first positioning holes at the corresponding positions on each first blank.

[0076] In step S15, for example, the stacked multi-layer first blanks are placed into a laminator or isostatic press, and a pre-pressing and shaping process is used to uniformly compact the multi-layer first blanks, expel the interlayer air, and tightly combine the multi-layer independent first blanks into a whole, thus completing the pre-forming of the first layer, and then set it aside for later use.

[0077] In this step, the pre-compression and shaping process conditions are: temperature range 40℃~90℃, pressure range 10MPa~20MPa, and holding time 2min~3min. Optionally, the temperature is 70℃, the pressure is 15MPa, and the holding time is 2min.

[0078] In some specific embodiments of the present invention, step S2, the step of pre-pressing and shaping the second blank to form the second layer, includes:

[0079] S21. Obtain multiple second blanks, the second blanks having the same shape and size as the first blanks.

[0080] S22. Drill holes in each of the second blanks to obtain multiple sub-holes.

[0081] S23. Multiple second blanks are stacked in alignment based on sub-openings to form a second blank body; wherein, multiple sub-openings located on each second blank are aligned and connected to form an opening.

[0082] S24. Pre-press and shape the second blank to form the second layer.

[0083] In this embodiment, the raw material for preparing the second blank is HTCC rolled tapered ceramic sheet of the same specifications and material as that used for preparing the first blank.

[0084] In step S21, for example, HTCC roll-shaped cast ceramic tiles with a thickness of 0.3mm to 1mm are placed into a precision cutting machine and cut into multiple second blanks. The shape of the second blanks can be, for example, a regular polygon, and the size can be, for example, 450mm × 450mm. The shape and size of the second blanks and the first blanks must be completely consistent to provide a basis for subsequent assembly and positioning. Afterwards, defective blanks with broken edges or uneven thickness are removed from the multiple second blanks, and blanks with regular size and flat surface are retained.

[0085] In step S22, for example, multiple second blanks are sequentially fixed on the worktable of a laser drilling machine, and the laser drilling machine is used to drill holes in the non-edge areas of the second blanks to obtain multiple sub-holes. After drilling, debris and burrs around the holes are cleaned to ensure that the inner walls of the holes are flat and the dimensions are accurate.

[0086] In step S23, for example, an automatic stacking machine is used to precisely align and stack multiple second blanks with completed openings based on the sub-openings, ensuring that the second blanks in each layer are completely overlapping, without offset, wrinkles, or foreign matter inclusions, to form a second blank. The multiple sub-openings located on each second blank are aligned and connected to form a through-hole. The number of stacked layers, i.e., the number of second blanks, for example, 2 to 10, determines the final opening depth, i.e., the depth of the cavity structure.

[0087] The reference for aligning and stacking multiple layers of second blanks can be, for example, in step S22, fixing the second blanks on the worktable of a CNC punching machine and using the CNC punching machine to punch holes in the edge area of ​​the second blanks to obtain multiple second positioning holes.

[0088] It should be noted that all second blanks used to prepare the second layer must be punched at the same location using a CNC punching machine to obtain multiple second positioning holes. The multiple second blanks are then stacked and positioned based on these second positioning holes. Specifically, the second positioning holes at corresponding positions on each second blank are aligned. It should be noted that, to ensure the lamination accuracy of the first and second layers, the positions of the second positioning holes on the second blanks must be consistent with the positions of the first positioning holes on the first blanks.

[0089] In step S24, for example, the stacked multi-layer second blanks are placed into a laminator or isostatic press, and a pre-pressing and shaping process is used to uniformly compact the multi-layer second blanks, expel the interlayer air, and tightly combine the multi-layer independent second blanks into a whole, thus completing the pre-forming of the second layer, and then set it aside for later use.

[0090] In this step, the pre-compression and shaping process conditions are: temperature range 40℃~90℃, pressure range 10MPa~20MPa, and holding time 2min~3min. Optionally, the temperature is 70℃, the pressure is 15MPa, and the holding time is 2min.

[0091] In some specific embodiments of the present invention, step S3, the step of bonding the first layer and the second layer, includes:

[0092] S31. After applying composite adhesive to the first layer and drying it, the second layer is bonded to the first layer, the first positioning hole and the second positioning hole are aligned, and the opening and the metal terminal are aligned.

[0093] S32. Perform lamination on the first and second layers after bonding.

[0094] In this embodiment, the composite adhesive is a special organic adhesive for ceramic green bodies, which is compatible with the material properties of green ceramic sheets. It features low-temperature drying and curing, complete volatilization during high-temperature sintering, no residue, and a shrinkage rate that matches that of green ceramic sheets. This composite adhesive is only used for bonding the interface between the first and second layers. After sintering, it will not affect the properties of the ceramic body, while ensuring that the first and second layers are tightly bonded without delamination or misalignment after bonding.

[0095] For example, the first layer is placed flat on the printing workbench, and a layer of composite adhesive is evenly applied only to the area near the second layer 2 where no metal terminals are formed. Then, the first layer with adhesive applied is placed smoothly into a constant temperature drying oven, and a suitable temperature is set for low-temperature drying. This allows the surface of the composite adhesive to quickly set and the interior to micro-cure, removing moisture and air bubbles from the adhesive layer. This results in a non-sticky, easily aligned adhesive layer while maintaining good bonding activity, preparing for subsequent lamination.

[0096] For example, the drying conditions for the composite adhesive are: a temperature range of 25°C to 80°C and a drying time range of 5 min to 60 min. Optionally, the temperature is 25°C and the drying time is 30 min to 60 min, for example, 45 min; or the temperature is 40°C to 80°C and the drying time is 5 min to 15 min; for example, 60°C and the drying time is 10 min.

[0097] For example, the first layer after the composite adhesive has dried is fixed to the base of the alignment and bonding machine. With the help of a vision alignment system, the second positioning hole is aligned with the first positioning hole as a reference, so that the second layer is pre-matched with the first layer. Then the second layer is slowly lowered to bond with the first layer, ensuring that the two layers are completely aligned and the openings on the second layer correspond precisely to the metal terminals on the first layer without offset or misalignment. After bonding, the double-layer structure is initially fixed.

[0098] For example, the vision alignment system includes an industrial camera and an image recognition algorithm module. The industrial camera simultaneously captures images of the positioning holes (first positioning hole and second positioning hole) on the first and second layers. The image recognition algorithm module quickly calculates the positional deviation between the first and second positioning holes and then sends the positional deviation data to the motion control system that controls the movement of the second layer. The motion control system then automatically adjusts the position of the second layer until the first and second positioning holes are perfectly aligned, achieving pre-matching of the first and second layers. At this point, the motion control system controls the second layer to slowly sink and adhere, thereby ensuring that the two layers are not only edge-aligned but also that the openings on the second layer can precisely pass through the metal terminals on the first layer.

[0099] In this embodiment, step S3 further includes a composite adhesive preparation step, which includes:

[0100] Heat water to 40℃~80℃, add polyvinyl alcohol and stir until completely dissolved.

[0101] Cool the temperature to 30℃~50℃, add polyethylene glycol and triacetin, and stir well.

[0102] Add octylphenol polyoxyethylene ether and borax, and continue stirring.

[0103] After cooling to room temperature and allowing to stand to defoam, a composite adhesive is obtained.

[0104] In the preparation steps of the composite adhesive, the raw materials by weight are as follows: 30 parts water, 15 parts polyvinyl alcohol, 40 parts polyethylene glycol, 10 parts triacetin, 3 parts octylphenol polyoxyethylene ether, and 2 parts borax.

[0105] In some specific embodiments of the present invention, in step S4, the first and second layers, after being assembled, are placed together in a laminator and laminated using a lamination process. This lamination process ensures a tight bond and seamless fit between the first and second layers while avoiding problems such as deformation of the openings on the second layer due to excessive pressure. After lamination, the multiple openings on the second layer form an open cavity structure with the first layer, through which the metal terminals are exposed.

[0106] In this embodiment, the lamination process conditions are: temperature range 25℃~60℃, pressure range 1MPa~5MPa, and holding time 1min~2min. The pressure during the lamination process is lower than the pre-compression pressure mentioned above. Optionally, the temperature is 30℃, the pressure is 3MPa, and the holding time is 1min; or the temperature is 25℃, the pressure is 5MPa, and the holding time is 2min.

[0107] The second embodiment of the present invention provides a method for preparing the above-mentioned HTCC ceramic green body with an open cavity structure, comprising the following steps:

[0108] S1. The first blank is pre-pressed and shaped to form the first layer, which has multiple metal terminals.

[0109] S2. The second blank is pre-pressed and shaped to form a second layer. The second layer has multiple openings, and each opening corresponds to a metal terminal.

[0110] S3. Attach the first layer and the second layer together, and align each opening with the corresponding metal terminal.

[0111] S4. The first and second layers are laminated to form an HTCC ceramic green body, with multiple openings forming an open cavity structure with the first layer, through which metal terminals are exposed. The pressure during the lamination process is less than the pressure applied to at least one of the first and second green bodies during pre-pressing and shaping.

[0112] S5. A layer of release film is laid on both the first and second surfaces of the ceramic green body, and it is placed between two laminates to form an intermediate product. After vacuum sealing with a packaging bag, it is pressed.

[0113] S6. After pressing, remove the packaging bag, pressure plate and release film in sequence.

[0114] S7. Sinter the pressed HTCC ceramic green body.

[0115] In this embodiment, the first and second layers are prepared separately, then bonded together and laminated as a whole to form a ceramic green body. This process of pre-pressing and shaping the separate layers before low-pressure lamination fundamentally solves the problems of deformation and collapse caused by external pressure on open-cavity structures. Simultaneously, by eliminating elastic gaskets and sacrificial filler materials, not only is the impact of residual carbon contamination on the performance of key components such as electrostatic chucks eliminated, but the selection and filling processes for support / filler materials are also eliminated, thereby reducing production complexity and material costs. Furthermore, the process parameters in the above preparation method are fully controllable, effectively reducing internal defects and broken wires, and significantly improving the overall performance and yield of the ceramic green body.

[0116] In this embodiment, the specific processes in steps S1 to S4 are as described above, and will not be repeated here.

[0117] In this embodiment, in step S5, the first and second surfaces of the ceramic green body are outer surfaces arranged opposite each other along its thickness direction. The release film, for example, can be a PET film. The thickness of the release film is 30μm to 200μm. The smooth surface of the release film adheres to the first and second surfaces of the ceramic green body, achieving demolding and preventing sticking. A pressure plate is added to the outside of the release film to ensure the flatness of the first and second surfaces, preventing indentations or uneven pressure on the ceramic green body surface during pressing. The pressure plate has a thickness of 0.5mm to 2mm and a surface roughness of 0.01μm to 0.03μm.

[0118] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing HTCC ceramic green bodies with an open cavity structure, characterized in that, Includes the following steps: The first blank is pre-pressed and shaped to form the first layer, which has multiple metal terminals; The second blank is pre-pressed and shaped to form a second layer. The second layer has multiple openings, and each of the multiple openings corresponds to a multiple of the metal terminals. The first layer and the second layer are bonded together, and each of the openings is aligned with the corresponding metal terminal; The first layer and the second layer are laminated to form the HTCC ceramic green body, and the plurality of openings form the cavity structure with the first layer, and the metal terminals are exposed through the openings; The pressure during the lamination process is less than the pressure of at least one of the first and second blanks during pre-pressing and shaping.

2. The preparation method according to claim 1, characterized in that, The step of pre-pressing and shaping the first blank to form the first layer includes: Multiple first blanks were obtained; Conductive holes are formed on at least one of the first blanks, and the conductive holes are filled with metal paste to electrically interconnect the interlayers within the first blanks. The metal terminal is formed by processing the location of the conductive hole. Multiple first blanks are aligned and stacked to form the first blank body; The first blank is pre-pressed and shaped to form the first block layer.

3. The preparation method according to claim 2, characterized in that, The step of pre-pressing and shaping the second blank to form the second layer includes: Multiple second blanks are obtained, and the second blanks have the same shape and size as the first blank. Drill holes in each of the second blanks to obtain multiple sub-openings; Multiple second blanks are stacked in alignment based on the sub-openings to form a second blank body; wherein the multiple sub-openings located on each of the second blanks are aligned and connected to form the openings; The second blank is pre-pressed and shaped to form the second layer.

4. The preparation method according to claim 3, characterized in that, Also includes: Drill holes in the edge areas of each of the first blanks to obtain multiple first positioning holes, and the multiple first blanks are aligned and stacked based on the first positioning holes. as well as, Drill holes in the edge areas of each of the second blanks to obtain multiple second positioning holes, and stack the multiple second blanks in alignment based on the second positioning holes; The second positioning hole corresponds one-to-one with the first positioning hole.

5. The preparation method according to claim 4, characterized in that, The step of bonding the first layer and the second layer includes: A composite adhesive is applied to the first layer, and after a drying process, the second layer is bonded to the first layer. The first positioning hole and the second positioning hole are aligned, and the opening is aligned with the metal terminal. The first and second layers after bonding are laminated.

6. The preparation method according to claim 5, characterized in that, The drying conditions for the composite adhesive are: temperature range 25℃~80℃, drying time range 5min~60min.

7. The preparation method according to claim 5, characterized in that, It also includes the preparation steps of the composite adhesive; The preparation steps of the composite adhesive include: Heat water to 40℃~80℃, add polyvinyl alcohol and stir until completely dissolved; Cool the temperature to 30℃~50℃, add polyethylene glycol and triacetin, and stir until well mixed; Add octylphenol polyoxyethylene ether and borax, and continue stirring; After cooling to room temperature and allowing to stand to defoam, the composite adhesive is obtained.

8. The preparation method according to any one of claims 1 to 7, characterized in that, The pre-pressing and shaping process conditions are: temperature range 40℃~90℃, pressure range 10MPa~20MPa, and holding time 2min~3min; the low-pressure lamination conditions are: temperature range 25℃~60℃, pressure range 1MPa~5MPa, and holding time 1min~2min.

9. The preparation method according to any one of claims 1 to 7, characterized in that, The HTCC ceramic green body includes a first surface and a second surface disposed opposite to each other along its thickness direction; the preparation method further includes: A layer of release film is laid on both the first and second surfaces, and then placed between two laminates to form an intermediate product. After vacuum sealing with a packaging bag, it is pressed. After pressing, remove the packaging bag, pressure plate, and release film in sequence; The HTCC ceramic green body after pressing is sintered.

10. The preparation method according to claim 9, characterized in that, The metal terminal is matched with the sintering linear shrinkage rate of the HTCC ceramic green body.

11. The preparation method according to claim 9, characterized in that, The thickness of the isolation membrane is 30μm to 200μm; the thickness of the pressure plate is 0.5mm to 2mm, and its surface roughness is 0.01μm to 0.03μm.

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