A post-processing method for MLCC by debinding and sintering integration

Abstract

The application relates to the technical field of multilayer ceramic capacitor (MLCC) preparation, and discloses a MLCC post-processing method integrating glue removal and sintering, which comprises the following steps: placing the cut MLCC ceramic green body into a heat treatment furnace and introducing an oxygen-containing atmosphere; establishing a low-temperature section heating curve, a medium-temperature section heating curve and a high-temperature section heating curve; removing glue in the low-temperature section and the medium-temperature section based on the low-temperature section heating curve and the medium-temperature section heating curve; switching the oxygen-containing atmosphere into a reducing atmosphere or an inert atmosphere after the medium-temperature section glue removal is completed, and removing glue in the high-temperature section based on the high-temperature section heating curve; switching the reducing atmosphere or the inert atmosphere into a non-oxidizing sintering atmosphere in a transition heat preservation process after the high-temperature section glue removal is completed; and performing high-temperature sintering in the non-oxidizing sintering atmosphere, so that the MLCC chip is obtained after cooling. The application can effectively solve the problems of low efficiency, high carbon residue, internal electrode oxidation and delamination cracking in the traditional separate process, and improve the density and electrical performance of the MLCC chip.

Description

Technical Field

[0001] This invention relates to an integrated post-processing method for debinding and sintering of MLCCs, belonging to the field of multilayer ceramic capacitor manufacturing technology. Background Technology

[0002] Multilayer ceramic capacitors (MLCCs) are a widely used passive electronic component. Their manufacturing process typically includes film casting, internal electrode printing, lamination, pressing, and cutting to form a ceramic green body. Subsequently, they undergo debinding and high-temperature sintering. In the debinding process, the organic binders, plasticizers, and other components in the green body are pyrolyzed and volatilized by heating to prevent carbon residue from forming during subsequent sintering and causing internal defects. The sintering process densifies the ceramic dielectric at a higher temperature to form a ceramic chip with the required electrical properties.

[0003] In traditional processes, debinding and sintering are completed independently in different equipment. Debinding is usually carried out in a debinding furnace. After debinding, the product needs to be cooled, transferred, and then sent to a sintering furnace for high-temperature sintering. However, this separate process has the following technical problems: After debinding, the product must be cooled to room temperature before it can be transferred. After transfer, it needs to be heated again for sintering. The multiple heating and cooling processes result in a lot of wasted time and energy consumption, leading to low production efficiency. Due to the oxidation resistance requirements of nickel internal electrodes at high temperatures, the single-atmosphere debinding process cannot simultaneously accommodate the rapid escape of small molecular weight organic compounds and the large molecular weight organic compounds. The complete decomposition of organic matter can easily lead to carbon residue, thus affecting the debinding effect. After debinding, the product is exposed to the air environment during the transfer process. The ceramic green body with the organic matter removed has a high porosity and easily absorbs moisture and oxygen, which can cause oxidation of the internal electrode and pose a risk of interface oxidation. If the large amount of gas generated by the rapid decomposition of organic matter during the debinding process is not discharged in time, it will cause stress concentration inside the green body, leading to structural defects such as delamination or cracking, and interlayer bonding defects. In addition, two independent equipment systems increase equipment investment costs and factory space, resulting in high equipment occupancy.

[0004] Therefore, existing technologies lack a solution that can effectively address the problems of low efficiency, high carbon residue, internal electrode oxidation, and delamination cracking in traditional discrete processes, thereby improving the density and electrical performance of MLCC chips. Summary of the Invention

[0005] This invention provides an integrated post-processing method for debinding and sintering of MLCCs. Its main purpose is to effectively solve the problems of low efficiency, high carbon residue, internal electrode oxidation and delamination cracking in traditional separate processes, thereby improving the density and electrical performance of MLCC chips.

[0006] To achieve the above objectives, the present invention provides an integrated post-processing method for debinding and sintering of MLCCs, comprising: The cut MLCC ceramic green body is placed into a heat treatment furnace, and an oxygen-containing atmosphere is introduced into the heat treatment furnace. Establish a multi-stage segmented heating curve for the ceramic green body, wherein the multi-stage segmented heating curve includes at least a low-temperature segment heating curve, a medium-temperature segment heating curve, and a high-temperature segment heating curve; Based on the low-temperature heating curve and the medium-temperature heating curve, the low-temperature and medium-temperature debinding of the ceramic green body is carried out in the oxygen-containing atmosphere. After the medium-temperature debinding is completed, the oxygen-containing atmosphere is switched to a reducing atmosphere or an inert atmosphere. Based on the high-temperature heating curve, the ceramic green body is debinded in the high-temperature stage in the reducing atmosphere or the inert atmosphere. After the high-temperature section is debinded, the ceramic green body is subjected to a transition heat preservation treatment, and during the transition heat preservation treatment, the reducing atmosphere or the inert atmosphere is switched to a non-oxidizing sintering atmosphere. The ceramic green body after the transition heat treatment is sintered at high temperature in the non-oxidizing sintering atmosphere, and after the high-temperature sintering is completed, the temperature in the heat treatment furnace is reduced to room temperature to obtain the sintered MLCC chip.

[0007] Optionally, in the oxygen-containing atmosphere, based on the low-temperature heating curve and the medium-temperature heating curve, the low-temperature debinding and medium-temperature debinding of the ceramic green body are performed, including: Thermogravimetric analysis was performed on the organic binder in the ceramic green body to determine the first decomposition temperature range of low molecular weight organic matter and the second decomposition temperature range of high molecular weight organic matter in the ceramic green body. The first temperature range of the low-temperature segment heating curve is set according to the first decomposition temperature range, and the second temperature range of the medium-temperature segment heating curve is set according to the second decomposition temperature range. In the oxygen-containing atmosphere, the furnace temperature corresponding to the ceramic green body is raised to the first temperature range according to the low-temperature section heating curve, and the ceramic green body is kept warm for a first preset time to allow the low molecular weight organic matter to be fully oxidized and decomposed, thereby obtaining the ceramic green body after low-temperature section debinding. After the low molecular weight organic matter is fully oxidized and decomposed, the furnace temperature is raised to the second temperature range according to the medium temperature range heating curve, and the ceramic green body is kept warm for a second preset time to allow the high molecular weight organic matter to be fully oxidized and decomposed, resulting in a ceramic green body after the medium temperature range binder is removed.

[0008] Optionally, in the oxygen-containing atmosphere, based on the low-temperature heating curve and the medium-temperature heating curve, the low-temperature debinding and medium-temperature debinding of the ceramic green body are performed, further comprising: Real-time monitoring of the furnace exhaust gas concentration corresponding to the ceramic green body; When the concentration of exhaust gas in the furnace exceeds the preset concentration threshold, the fresh air volume of the oxygen-containing atmosphere is adjusted to maintain the concentration of exhaust gas in the furnace within the preset concentration range, thereby completing the low-temperature section and medium-temperature section glue removal of the ceramic green body.

[0009] Optionally, based on the high-temperature heating curve, the ceramic green body undergoes high-temperature debinding in the reducing atmosphere or the inert atmosphere, including: In the reducing atmosphere or the inert atmosphere, the furnace temperature of the ceramic green body is raised to the high-temperature section debinding temperature according to the high-temperature section heating curve, so that the residual high molecular weight organic matter in the ceramic green body is decomposed and discharged to obtain a preliminary debinding green body. At the high-temperature debinding temperature, the pre-debinded green body is kept at a third preset time to further remove residual carbon from the ceramic green body, thus obtaining a ceramic green body after high-temperature debinding. The third preset duration is set according to the size of the ceramic green body, the organic matter content, and the target residual carbon content.

[0010] Optionally, after the binder is removed in the high-temperature section, the ceramic green body undergoes a transitional heat preservation treatment, including: After the high-temperature section glue removal is completed, the ceramic green body is cooled to a preset transition heat preservation temperature, or the ceramic green body is kept at the high-temperature section glue removal temperature. The ceramic green body is kept at the high-temperature section glue removal temperature or the transition heat preservation temperature for a preset transition time to obtain a transition heat preservation treated green body. The temperature difference between the transition insulation temperature and the high-temperature section adhesive discharge temperature is within ±50℃; the transition insulation temperature is preset according to the thermal stability temperature range of the constituent materials of the ceramic green body.

[0011] Optionally, the ceramic green body after the transition holding treatment is subjected to high-temperature sintering in the non-oxidizing sintering atmosphere, including: The ceramic green body after the transition heat preservation treatment is heated to the sintering temperature in the non-oxidizing sintering atmosphere at a preset sintering heating rate. The ceramic green body is kept at the sintering temperature for a fourth preset time, so that the ceramic green body completes densification and shrinkage during the heating and holding process, and the sintered ceramic chip is obtained. The sintering heating rate is preset based on the thickness of the dielectric layer of the ceramic green body and the sintering activity of the ceramic powder; the fourth preset duration is preset based on the thickness of the dielectric layer of the ceramic green body and the sintering temperature.

[0012] Optionally, the oxygen-containing atmosphere is air or an oxygen-enriched atmosphere with an oxygen volume fraction of 5% to 21%; the reducing atmosphere or inert atmosphere is nitrogen, argon, or a mixture of nitrogen and hydrogen, and the hydrogen volume fraction in the mixture is ≤5%; the non-oxidizing sintering atmosphere is nitrogen or a mixture of nitrogen and hydrogen, and the oxygen volume fraction in the mixture is less than 10 ppm.

[0013] Optionally, establishing a multi-stage segmented heating curve for the ceramic green body includes: Identify the types of organic binders in the ceramic green body, and determine the thermal decomposition characteristic temperature range of the ceramic green body based on the types of organic binders. Based on the thermal decomposition characteristic temperature range, the glue removal process of the ceramic green body is divided into a low-temperature section, a medium-temperature section, and a high-temperature section. The thickness of the dielectric layer and the internal electrode material of the ceramic green body are obtained to define the heating rate and holding time corresponding to each temperature stage; Based on the temperature stages, the heating rate, and the holding time, a multi-stage segmented heating curve for the ceramic green body is generated.

[0014] Optionally, the heat treatment furnace is an atmosphere-controllable box-type debinding and sintering integrated furnace that integrates a furnace body heating module, a vacuum system module, a gas input and output module, a multi-point temperature detection module, and a PLC control module.

[0015] Optionally, before placing the cut MLCC ceramic green body into the heat treatment furnace, the process further includes: placing the ceramic green body in a medium containing zirconium powder or titanium dioxide powder for tumbling treatment, so that a powder coating layer is formed on the surface of the ceramic green body.

[0016] Compared to the problems described in the background art, this invention, by directly placing the MLCC ceramic green body into the heat treatment furnace and introducing an oxygen-containing atmosphere, allows for continuous completion of debinding and sintering within the same equipment. This avoids the cooling, transfer, and reheating operations of the ceramic green body between debinding and sintering, thereby simplifying the post-processing of the MLCC ceramic green body and improving production efficiency. Furthermore, by switching the oxygen-containing atmosphere to a reducing or inert atmosphere after the debinding in the intermediate temperature section, this invention can prevent the oxidized and decomposed products from undergoing secondary cracking at higher temperatures, forming carbon deposits. By switching the atmosphere during the transition heat preservation process, this invention can achieve a seamless connection between the debinding atmosphere and the sintering atmosphere within the closed furnace cavity, avoiding internal electrode oxidation and moisture adsorption caused by the ceramic green body being exposed to the air environment during transfer, while ensuring that it enters the high-temperature firing stage. During the sintering stage, the furnace atmosphere is pre-set to the low-oxygen conditions required for sintering, thereby improving the interface quality and electrical reliability of the MLCC chip. Furthermore, this invention performs high-temperature sintering of the ceramic green body after the transition heat treatment in the non-oxidizing sintering atmosphere. This protects the nickel internal electrode from oxidation, inhibits the reduction of the ceramic dielectric, and eliminates thermal stress following the transition heat treatment, achieving an integrated continuous process of debinding and sintering. Finally, after the high-temperature sintering, the temperature inside the heat treatment furnace is lowered to room temperature to obtain the sintered MLCC chip. This achieves continuous completion of the MLCC debinding and sintering processes within the same equipment, avoiding the thermal stress cycle caused by cooling, transfer, and reheating in traditional processes. This results in MLCC chips with intact structure, no delamination or cracking, no oxidation of the internal electrode, and excellent electrical performance. Therefore, this invention effectively solves the problems of low efficiency, high carbon residue, internal electrode oxidation, and delamination cracking in traditional discrete processes, improving the density and electrical performance of MLCC chips. Attached Figure Description

[0017] Figure 1 This is a schematic flowchart of an integrated debinding and sintering post-processing method for MLCCs provided in an embodiment of the present invention. Figure 2 A schematic diagram of the atmosphere control principle of the heat treatment furnace for an integrated debinding and sintering post-treatment method for MLCCs provided in an embodiment of the present invention. Figure 3 A schematic diagram of the temperature-atmosphere-time curve of the multi-stage segmented debinding and sintering integrated process of the MLCC debinding and sintering integrated post-treatment method provided in an embodiment of the present invention. Figure 4 Metallographic microscopic comparison of cross-sections of MLCC products provided by the integrated debinding and sintering post-processing method for MLCCs according to an embodiment of the present invention. Figure 5A schematic diagram of a module for implementing an integrated debinding and sintering post-processing system for MLCCs according to an embodiment of the present invention; Figure 6 A schematic diagram of a computer device for implementing an integrated debinding and sintering post-processing method for MLCCs according to an embodiment of the present invention; The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and the accompanying drawings. Detailed Implementation

[0018] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0019] This application provides an integrated debinding and sintering post-processing method for MLCCs. The executing entity of this integrated debinding and sintering post-processing method for MLCCs includes, but is not limited to, at least one of the following electronic devices that can be configured to execute the method provided in this application: a server, a terminal, etc. In other words, the integrated debinding and sintering post-processing method for MLCCs can be executed by software or hardware installed on a terminal device or a server device. The server includes, but is not limited to, a single server, a server cluster, a cloud server, or a cloud server cluster.

[0020] See Figure 1 The diagram shown is a flowchart illustrating an integrated debinding and sintering post-processing method for MLCCs according to an embodiment of the present invention. In this embodiment, the integrated debinding and sintering post-processing method for MLCCs includes: S1. Place the cut MLCC ceramic green body into a heat treatment furnace and introduce an oxygen-containing atmosphere into the heat treatment furnace.

[0021] This invention allows for the direct placement of MLCC ceramic green bodies into a heat treatment furnace and the introduction of an oxygen-containing atmosphere, enabling the debinding and sintering processes to be completed continuously within the same equipment. This avoids the cooling, transfer, and reheating operations of the ceramic green bodies between debinding and sintering, thereby simplifying the post-processing of MLCC ceramic green bodies and improving production efficiency.

[0022] The MLCC ceramic green body refers to a multilayer ceramic capacitor semi-finished product that has undergone casting, internal electrode printing, lamination, pressing, and cutting processes but has not yet undergone debinding and sintering. It contains a nickel internal electrode and a ceramic dielectric layer. The oxygen-containing atmosphere is air or an oxygen-rich atmosphere with a volume fraction of 5% to 21%, used to promote the full oxidation and decomposition of small molecular weight organic compounds during the subsequent low-temperature and medium-temperature debinding processes.

[0023] Preferably, the heat treatment furnace is an atmosphere-controllable box-type debinding and sintering integrated furnace, wherein the box-type debinding and sintering integrated furnace includes a furnace body heating module, a vacuum system module, a gas input / output module, a multi-point temperature detection module, and a PLC control module. The vacuum system module and the gas input / output module together constitute a furnace cavity atmosphere control unit. This furnace cavity atmosphere control unit, under the control of the PLC control module, performs vacuuming, vacuum breaking, and atmosphere switching operations, thereby enabling the debinding and sintering integrated furnace to automatically and continuously complete the debinding and sintering processes within the same furnace cavity according to a preset process program. The multi-point temperature detection module is used to monitor the temperature at multiple different locations within the furnace cavity in real time and feeds back the monitored temperature data to the PLC control module. The PLC control module determines whether each process stage has reached the set conditions based on the temperature data. The PLC control module is electrically connected to the furnace body heating module, the vacuum system module, the gas input / output module, and the multi-point temperature detection module, and is used to control the furnace body heating module to perform heating, holding, and cooling steps according to the preset process program.

[0024] See Figure 2 The diagram shows the atmosphere control principle of the heat treatment furnace provided by this invention. As shown, the vacuum system module and the gas input / output module together constitute the furnace atmosphere control unit. This unit performs vacuuming, vacuum breaking, and atmosphere switching operations under the scheduling of the PLC control module. Specifically: before the glue removal begins and during atmosphere switching, the vacuum system module performs a vacuuming operation to remove residual air from the furnace; during the glue removal process, the gas input / output module cooperates to perform a vacuum breaking operation and maintain a slight positive pressure; during atmosphere switching, the vacuum system module and the gas input / output module work together to complete the "vacuuming-gas filling" replacement sequence. Through the above operations, the glue removal and sintering integrated furnace can automatically and continuously complete the glue removal and sintering processes in the same furnace cavity according to a preset process program.

[0025] In an optional embodiment of the present invention, the cut MLCC ceramic green body can be supported by an alumina support frame and placed into the heat treatment furnace.

[0026] In another optional embodiment of the present invention, before placing the cut MLCC ceramic green body into the heat treatment furnace, the method further includes: placing the ceramic green body in a medium containing zirconium powder or titanium dioxide powder for tumbling treatment, so that a powder coating layer is formed on the surface of the ceramic green body.

[0027] The powder coating layer is a layer of zirconium powder or titanium dioxide powder particles attached to the surface of the ceramic green body. This layer isolates adjacent ceramic green bodies during the debinding and sintering process, preventing them from sticking together due to softening or localized melting of the green body surface at high temperatures. The tumbling process is achieved using a tumbling mill. Specifically, the ceramic green body and a medium containing zirconium powder or titanium dioxide powder are loaded into the tumbling mill drum in a certain proportion. The rotation of the drum causes relative movement between the ceramic green body and the medium. The friction and impact of the medium uniformly adhere the powder to the surface of the ceramic green body.

[0028] It should be noted that the powder covering layer formed on the surface of the ceramic green body can play a physical isolation role during the debinding and sintering process. This can effectively reduce the direct contact between adjacent ceramic green bodies, thereby preventing mutual adhesion caused by softening or local melting of the ceramic green body surface at high temperature. This ensures the individual separability and appearance integrity of the MLCC chip after sintering, while avoiding mechanical damage caused by external force peeling off the adhered chip.

[0029] S2. Establish a multi-stage segmented heating curve for the ceramic green body, wherein the multi-stage segmented heating curve includes at least a low-temperature segment heating curve, a medium-temperature segment heating curve, and a high-temperature segment heating curve.

[0030] By establishing a multi-stage segmented heating curve for the ceramic green body, this invention can disperse the removal process of organic matter in three temperature ranges—low temperature, medium temperature, and high temperature—and carry it out step by step, thus avoiding the problem of stress concentration inside the ceramic green body caused by the concentrated decomposition and release of a large amount of gas from organic matter.

[0031] Specifically, the multi-stage segmented heating curve includes at least a low-temperature heating curve, a medium-temperature heating curve, and a high-temperature heating curve. The heating rate of the low-temperature heating curve is 1–3 °C / min; the heating rate of the medium-temperature heating curve is 0.5–2 °C / min; the heating rate of the high-temperature heating curve is 1–3 °C / min; and the heating rate of the high-temperature sintering stage is 2–10 °C / min.

[0032] See Figure 3The figure shows a schematic diagram of the temperature-atmosphere-time curves for the multi-stage segmented debinding and sintering integrated process provided by the present invention. As shown, the horizontal axis represents the process time (h), and the vertical axis represents the furnace temperature (°C). The figure distinguishes three atmosphere stages with different background patterns: the first atmosphere is the oxygen-containing atmosphere, the second atmosphere is the reducing or inert atmosphere, and the third atmosphere is the non-oxidizing sintering atmosphere. The entire process is divided into six stages in chronological order: ① low-temperature debinding, ② medium-temperature debinding, ③ high-temperature debinding, ④ transitional heat preservation, ⑤ high-temperature sintering, and ⑥ cooling. It can be clearly seen from the figure that the atmosphere automatically switches according to a preset program as the temperature range changes, sequentially: oxygen-containing atmosphere (stages ①+②) → reducing or inert atmosphere (stages ③+④) → non-oxidizing sintering atmosphere (stages ⑤+⑥), without any exposure steps to room temperature in between.

[0033] As an embodiment of the present invention, establishing the multi-stage segmented heating curve of the ceramic green body includes: Identify the types of organic binders in the ceramic green body, and determine the thermal decomposition characteristic temperature range of the ceramic green body based on the types of organic binders. Based on the thermal decomposition characteristic temperature range, the glue removal process of the ceramic green body is divided into a low-temperature section, a medium-temperature section, and a high-temperature section. The thickness of the dielectric layer and the material of the internal electrode of the ceramic green body are obtained in order to define the heating rate and holding time corresponding to each temperature stage; Based on the temperature stages, the heating rate, and the holding time, a multi-stage segmented heating curve for the ceramic green body is generated.

[0034] The organic adhesive includes one or more of polyvinyl butyral, polyacrylate, ethyl cellulose, and polyethylene glycol. The thermal decomposition characteristic temperature range refers to the temperature range between the initial and final weight loss temperatures of the organic adhesive in thermogravimetric analysis (TGA). Specifically, the thermal decomposition characteristic temperature range for low molecular weight organic adhesives is 150–250°C, and for high molecular weight organic adhesives, it is 300–450°C. The heating rate is used to control the rate of heating of the ceramic green body within each temperature range to avoid delamination or cracking of the ceramic green body due to rapid heating and concentrated decomposition of organic matter releasing gases. The holding time is used to ensure sufficient removal of organic matter within each temperature range to reduce the carbon residue after adhesive removal. The dielectric layer thickness is the geometric dimension of a single layer of ceramic dielectric in the ceramic green body, obtained using a laser thickness gauge or a contact thickness gauge. The internal electrode material is nickel or a nickel-based alloy.

[0035] Optionally, the type of organic binder is determined according to the preparation formula of the ceramic green body.

[0036] S3. Based on the low-temperature section heating curve and the medium-temperature section heating curve, perform low-temperature section glue removal and medium-temperature section glue removal of the ceramic green body in the oxygen-containing atmosphere.

[0037] This invention removes the binder from the ceramic green body at low and medium temperatures in an oxygen-containing atmosphere based on the low-temperature and medium-temperature heating curves. This allows for targeted oxidation and decomposition of low-molecular-weight and high-molecular-weight organic compounds within different temperature ranges, achieving a stepwise and thorough removal of the organic binder and minimizing the generation of carbonaceous residues.

[0038] As an embodiment of the present invention, in the oxygen-containing atmosphere, based on the low-temperature heating curve and the medium-temperature heating curve, the low-temperature debinding and medium-temperature debinding of the ceramic green body are performed, including: Thermogravimetric analysis was performed on the organic binder in the ceramic green body to determine the first decomposition temperature range of low molecular weight organic matter and the second decomposition temperature range of high molecular weight organic matter in the ceramic green body. The first temperature range of the low-temperature segment heating curve is set according to the first decomposition temperature range, and the second temperature range of the medium-temperature segment heating curve is set according to the second decomposition temperature range. In the oxygen-containing atmosphere, the furnace temperature corresponding to the ceramic green body is raised to the first temperature range according to the low-temperature section heating curve, and the ceramic green body is kept warm for a first preset time to allow the low molecular weight organic matter to be fully oxidized and decomposed, thereby obtaining the ceramic green body after low-temperature section debinding. After the low molecular weight organic matter is fully oxidized and decomposed, the furnace temperature is raised to the second temperature range according to the medium temperature range heating curve, and the ceramic green body is kept warm for a second preset time to allow the high molecular weight organic matter to be fully oxidized and decomposed, resulting in a ceramic green body after the medium temperature range binder is removed.

[0039] Wherein, the low molecular weight organic matter refers to organic additives with a molecular weight less than 1000 Daltons, including dispersants and / or plasticizers, whose thermal decomposition characteristic temperature range is 150~250℃; the high molecular weight organic matter refers to organic adhesives with a molecular weight greater than 10000 Daltons, including polyvinyl butyral, polyacrylate and / or ethyl cellulose, whose thermal decomposition characteristic temperature range is 300~450℃; the first temperature range of 150~200℃ is set according to the thermal decomposition characteristic temperature range of the low molecular weight organic matter; the second temperature range of 250~300℃ is set according to the thermal decomposition characteristic temperature range of the high molecular weight organic matter; the first preset time is 1~4h, and the second preset time is 2~6h.

[0040] It should be noted that the first preset duration and the second preset duration are adjusted according to the size of the ceramic green body, the thickness of the medium layer and the content of organic binder, so as to ensure that the organic matter is fully decomposed and released.

[0041] Optionally, the thermal decomposition characteristic temperature ranges of the low molecular weight organic compounds and the high molecular weight organic compounds are determined by thermogravimetric analysis. Specifically, using a thermogravimetric analyzer, the temperature is heated from room temperature to 800°C at a heating rate of 10°C / min in air, and the weight loss curve and its first derivative curve are recorded. The temperature range corresponding to the first weight loss peak in the first derivative curve is taken as the thermal decomposition characteristic temperature range of the low molecular weight organic compounds, and the temperature range corresponding to the second weight loss peak in the first derivative curve is taken as the thermal decomposition characteristic temperature range of the high molecular weight organic compounds.

[0042] In another embodiment of the present invention, based on the low-temperature heating curve and the medium-temperature heating curve, the low-temperature debinding and medium-temperature debinding of the ceramic green body are performed in the oxygen-containing atmosphere, further comprising: Real-time monitoring of the furnace exhaust gas concentration corresponding to the ceramic green body; When the concentration of exhaust gas in the furnace exceeds the preset concentration threshold, the fresh air volume of the oxygen-containing atmosphere is adjusted to maintain the concentration of exhaust gas in the furnace within the preset concentration range, thereby completing the low-temperature section and medium-temperature section glue removal of the ceramic green body.

[0043] The furnace exhaust gas concentration is the total concentration of volatile gases monitored by an online exhaust gas concentration monitoring sensor installed at the furnace exhaust port; the preset concentration threshold is set based on at least one factor: the thickness of the dielectric layer of the ceramic green body and the content of the organic binder; the preset concentration range is 1~4 g / m³. 3 The lower limit of the preset concentration range is determined based on the thickness of the dielectric layer of the ceramic green body, and the upper limit of the preset concentration range is determined based on the organic binder content of the ceramic green body. For example, when the dielectric layer thickness of the ceramic green body is less than 3 μm or the organic binder content is higher than 10 wt%, the lower limit of the preset concentration range is set to 1 g / m³. 3 To prevent delamination and cracking of the ceramic green body due to concentrated gas release; when the thickness of the medium layer of the ceramic green body is greater than or equal to 3 μm and the content of organic binder is less than or equal to 10 wt%, the upper limit of the preset concentration range is set to 4 g / m³. 3 To improve glue removal efficiency.

[0044] S4. After the medium-temperature debinding is completed, the oxygen-containing atmosphere is switched to a reducing atmosphere or an inert atmosphere. Based on the high-temperature heating curve, the ceramic green body is debinded in the high-temperature stage in the reducing atmosphere or the inert atmosphere.

[0045] By switching the oxygen-containing atmosphere to a reducing atmosphere or an inert atmosphere after the desiccation process in the intermediate temperature range, this invention can prevent the oxidized and decomposed products from undergoing secondary cracking and forming carbon deposits at higher temperatures.

[0046] Specifically, the reducing or inert atmosphere is nitrogen, argon, or a mixture of nitrogen and hydrogen. Nitrogen and argon are inert gases and do not react with the nickel internal electrode at high temperatures. In the nitrogen-hydrogen mixture, hydrogen has reducing properties and can promote the cracking and removal of residual high-molecular-weight organic matter. However, an excessively high hydrogen content can easily lead to hydrogen embrittlement of the nickel internal electrode. Therefore, the hydrogen content in the mixture is preferably ≤5%.

[0047] It should be noted that before switching to the reducing atmosphere or the inert atmosphere, the oxygen concentration in the furnace should be ensured to be below 50 ppm to prevent residual oxygen from oxidizing the nickel inner electrode at high temperatures.

[0048] As a preferred embodiment of the present invention, when switching the oxygen-containing atmosphere to the reducing atmosphere or inert atmosphere, the specific replacement steps are as follows: First, close the inlet valve of the oxygen-containing atmosphere to stop the supply of the oxygen-containing atmosphere; second, start the vacuum system module to pump the pressure inside the furnace cavity to below 10 Pa, so that the oxygen-containing atmosphere remaining in the furnace cavity is fully extracted; then, open the inlet valve of the reducing atmosphere or inert atmosphere to fill the furnace cavity with the reducing atmosphere or inert atmosphere until the pressure inside the furnace returns to atmospheric pressure (0.1 MPa); repeat the above "vacuuming-filling" replacement steps 2 to 3 times; finally, after confirming that the oxygen concentration inside the furnace cavity is below 10 ppm, maintain the continuous supply of the reducing atmosphere or inert atmosphere.

[0049] Further, based on the high-temperature heating curve, the ceramic green body undergoes high-temperature debinding in the reducing atmosphere or the inert atmosphere, including: In the reducing atmosphere or the inert atmosphere, the furnace temperature of the ceramic green body is raised to the high-temperature section debinding temperature according to the high-temperature section heating curve, so that the residual high molecular weight organic matter in the ceramic green body is decomposed and discharged to obtain a preliminary debinding green body. At the high-temperature debinding temperature, the pre-debinded green body is kept at a third preset time to further remove residual carbon from the ceramic green body, thus obtaining a ceramic green body after high-temperature debinding. The third preset duration is set according to the size of the ceramic green body, the organic matter content, and the target residual carbon content.

[0050] Specifically, the high-temperature section debinding temperature is 400–500°C, which is the target temperature for debinding in the high-temperature section; the third preset duration is set to 2–8 hours based on the size of the ceramic green body, the organic matter content, and the target residual carbon content. Specifically, for every 0.5 mm increase in the thickness of the ceramic green body, the third preset duration is extended by 0.5–1 hour; for every 5 wt% increase in the organic matter content, the third preset duration is extended by 1–2 hours. The residual carbon is characterized by the amount of carbon residue in the sintered ceramic chip, expressed in ppm, and can be determined using a carbon-sulfur analyzer or thermogravimetric analysis.

[0051] As an example, when the thickness of the ceramic green body is 1.0 mm, the organic content is 10 wt%, and the target residual carbon content is no higher than 50 ppm, the high-temperature debinding temperature is set to 450°C, and the third preset time is set to 4 hours. The measured residual carbon content of the debinded green body is 35 ppm. When the thickness of the ceramic green body increases to 1.5 mm and the organic content increases to 15 wt%, the third preset time is correspondingly extended to 6 hours, and the residual carbon content can still be controlled below 50 ppm.

[0052] S5. After the adhesive is removed in the high-temperature section, the ceramic green body is subjected to a transition heat preservation treatment, and during the transition heat preservation treatment, the reducing atmosphere or the inert atmosphere is switched to a non-oxidizing sintering atmosphere.

[0053] This invention, by setting up a transitional heat preservation treatment from debinding to sintering, allows the atmosphere and temperature inside the furnace to reach a steady transition before entering high-temperature sintering. This avoids the thermal stress impact caused by the cooling and reheating of ceramic green bodies in traditional processes, effectively reducing the risk of cracking of ceramic green bodies in the early stage of sintering and improving product yield.

[0054] As an embodiment of the present invention, after the adhesive is removed in the high-temperature section, the ceramic green body undergoes a transitional heat preservation treatment, including: After the high-temperature section glue removal is completed, the ceramic green body is cooled to a preset transition heat preservation temperature, or the ceramic green body is kept at the high-temperature section glue removal temperature. The ceramic green body is kept at the high-temperature section glue removal temperature or the transition heat preservation temperature for a preset transition time to obtain a transition heat preservation treated green body. The temperature difference between the transition insulation temperature and the high-temperature section adhesive discharge temperature is within ±50℃; the transition insulation temperature is preset according to the thermal stability temperature range of the constituent materials of the ceramic green body.

[0055] Specifically, the preset transition time is 0.5 to 2 hours, which can be preset according to the gas replacement time required to switch the furnace atmosphere from the reducing atmosphere or the inert atmosphere to the non-oxidizing sintering atmosphere, and the time required for the ceramic green body to reach uniform internal temperature at the high-temperature section debinding temperature or the transition heat preservation temperature.

[0056] Preferably, when the high-temperature section glue discharge temperature is set to 450°C, the transition insulation temperature is set to 420-440°C; when the high-temperature section glue discharge temperature is set to 480°C, the transition insulation temperature is set to 450-470°C.

[0057] Furthermore, by switching the atmosphere during the transition heat preservation process, the present invention can achieve a seamless connection between the debinding atmosphere and the sintering atmosphere in the closed furnace cavity, avoiding the oxidation of the internal electrode and moisture adsorption caused by the ceramic green body being exposed to the air environment during transfer. At the same time, it ensures that the atmosphere in the furnace has reached the low oxygen conditions required for sintering before entering the high-temperature sintering stage, thereby improving the interface quality and electrical reliability of the MLCC chip.

[0058] In detail, the non-oxidizing sintering atmosphere refers to the atmosphere used to protect the nickel internal electrode from oxidation during the high-temperature sintering process, specifically nitrogen or a mixture of nitrogen and hydrogen, and the oxygen volume fraction in the atmosphere is less than 10 ppm.

[0059] In an optional embodiment of the present invention, switching the reducing atmosphere or inert atmosphere to the non-oxidizing sintering atmosphere includes: closing the inlet valve of the reducing atmosphere or inert atmosphere, simultaneously introducing the non-oxidizing sintering atmosphere at a flow rate of 0.5–5 L / min, and opening the exhaust valve to maintain the furnace pressure at a slightly positive pressure of 0.1–0.12 MPa. During the switching process, the oxygen content of the outlet gas is monitored. When the oxygen content remains below 10 ppm for more than 10 minutes, the atmosphere switching is considered complete. The switching time is 15–45 minutes, which is included within the preset transition time.

[0060] In a preferred embodiment of the present invention, during the entire integrated debinding and sintering process, the pressure inside the heat treatment furnace is maintained at a slightly positive pressure of 0.1–0.12 MPa. This slightly positive pressure is achieved through the coordinated adjustment of the air intake flow rate of the gas input / output module and the opening degree of the exhaust valve.

[0061] Furthermore, the flow rate of the introduced atmosphere in each stage is controlled within the following ranges: the flow rate of the oxygen-containing atmosphere in the low-temperature and medium-temperature debinding stages is 1–10 L / min; the flow rate of the reducing or inert atmosphere in the high-temperature debinding stage is 1–10 L / min; and the flow rate of the non-oxidizing sintering atmosphere in the high-temperature sintering stage is 0.5–5 L / min.

[0062] S6. The ceramic green body after the transition heat preservation treatment is sintered at high temperature in the non-oxidizing sintering atmosphere, and after the high temperature sintering is completed, the temperature in the heat treatment furnace is reduced to room temperature to obtain the sintered MLCC chip.

[0063] The present invention performs high-temperature sintering of the ceramic green body after the transition heat preservation treatment in the non-oxidizing sintering atmosphere, which can protect the nickel internal electrode from oxidation, inhibit the reduction of the ceramic medium, and eliminate thermal stress by taking over the transition heat preservation treatment, thereby realizing an integrated continuous process of debinding and sintering.

[0064] As an embodiment of the present invention, the ceramic green body after the transition heat preservation treatment is subjected to high-temperature sintering in the non-oxidizing sintering atmosphere, including: The ceramic green body after the transition heat preservation treatment is heated to the sintering temperature in the non-oxidizing sintering atmosphere at a preset sintering heating rate. The ceramic green body is held at the sintering temperature for a fourth preset time, so that the ceramic green body completes densification and shrinkage during the heating and holding process, and the sintered ceramic chip is obtained. The sintering heating rate is preset based on the thickness of the dielectric layer of the ceramic green body and the sintering activity of the ceramic powder.

[0065] The sintering heating rate is 2~10℃ / min, used to control the grain nucleation rate and grain boundary migration speed of the ceramic dielectric layer during the heating process. The sintering temperature is 1100~1350℃, specifically determined based on the ceramic dielectric material system of the ceramic green body. The fourth preset duration is 1~4h, used to ensure sufficient densification of the ceramic dielectric layer. The sintered ceramic chip refers to a multilayer ceramic capacitor chip that has completed dielectric layer densification and possesses the required electrical properties.

[0066] Furthermore, by reducing the temperature inside the heat treatment furnace to room temperature after the high-temperature sintering is completed, the present invention obtains a sintered MLCC chip, thereby achieving the continuous completion of the MLCC debinding and sintering processes in the same equipment. This avoids the thermal stress cycle caused by cooling, transfer, and reheating in traditional processes, thus obtaining an MLCC chip with a complete structure, no delamination or cracking, no oxidation of the internal electrodes, and excellent electrical performance.

[0067] Specifically, the heat treatment furnace is cooled from the sintering temperature to 800°C at a cooling rate of 0.5–5°C / min, and then the cooling program is stopped, allowing the furnace temperature to cool naturally to room temperature. Throughout the cooling process, the non-oxidizing sintering atmosphere is continuously introduced into the heat treatment furnace to keep the oxygen volume fraction in the furnace below 10 ppm, so as to prevent the nickel inner electrode from oxidizing due to contact with oxygen during the cooling stage.

[0068] To verify the technical effects of this invention in improving the debinding effect of MLCC ceramic green bodies, preventing oxidation of nickel internal electrodes, and enhancing the density and electrical properties of ceramic dielectric layers, the following comparative experiment was designed.

[0069] Experimental group: Prepared according to the method described in this invention: The cut MLCC ceramic green body (dielectric layer thickness 3μm, internal electrode Ni, organic binder PVB) was pretreated by tumbling in a zirconium powder-containing dielectric to form a powder coating layer on the surface of the green body; the pretreated green body was loaded onto an alumina sintering mesh and placed in an integrated debinding and sintering furnace; after evacuating the furnace, air was introduced to create an oxygen-containing atmosphere, maintaining a slightly positive pressure inside the furnace; debinding was performed according to a multi-stage segmented heating curve: the low-temperature section was heated to 180°C at a rate of 2°C / min. The temperature was maintained at ℃ for 2 hours, and then increased to 280℃ at a rate of 0.5℃ / min and held for 4 hours. The temperature was then switched to N2 as an inert atmosphere and increased to 450℃ at a rate of 1.5℃ / min and held for 4 hours. The temperature was then maintained at 450℃ for 1 hour for transitional holding, while the temperature was switched to a N2+H2 mixture (H2 volume fraction 2%) as a non-oxidizing sintering atmosphere. The temperature was then increased to 1230℃ at a rate of 5℃ / min and held for 2.5 hours for sintering. The temperature was then decreased to 800℃ at a rate of 3℃ / min and cooled with the furnace to obtain the MLCC chip.

[0070] Control group: MLCC ceramic green bodies from the same batch as the experimental group (3μm dielectric layer thickness, Ni internal electrode, PVB organic binder). The green bodies were placed in a debinding furnace and debinded under air atmosphere according to the following debinding curve: heating from room temperature to 250℃ at a rate of 1℃ / min, holding for 2 hours; then heating from 250℃ to 400℃ at a rate of 1℃ / min, holding for 6 hours. After debinding, the green bodies were cooled to room temperature with the furnace. Once completely cooled, the green bodies were removed from the debinding furnace and transferred to a sintering furnace. In the sintering furnace, a N2+H2 mixture (2% H2 volume fraction) was introduced, and the temperature was increased to 1230℃ at a rate of 5℃ / min, holding for 2.5 hours for sintering. After sintering, the temperature was decreased to 800℃ at a rate of 3℃ / min, and then allowed to cool naturally to room temperature with the furnace. All other conditions (such as green body loading method and firing plate material) remained the same as the experimental group.

[0071] Test methods: Carbon residue was determined using a carbon-sulfur analyzer (according to GB / T 4698.14-2011 or similar standards); dielectric layer density was determined using Archimedes' water displacement method (according to GB / T 25995-2010); dielectric constant and loss factor were determined using an LCR digital bridge (according to GB / T 5593-2015) at 1 kHz and 25 °C; insulation resistance was determined using a high-resistance meter (according to GB / T 5593-2015); breakdown voltage was determined using a withstand voltage tester (according to GB / T 5593-2015); microstructure was observed using a metallographic microscope and a scanning electron microscope (SEM): the metallographic microscope was used for low-magnification observation of the overall cross-sectional morphology of the ceramic chip, including the alternating stacked structure of the dielectric layer and the internal electrode, the distribution of delamination cracks and pores; the scanning electron microscope was used for high-magnification observation of the grain morphology, grain size distribution, densification degree of the ceramic dielectric layer, and the bonding state of the internal electrode and the ceramic interface.

[0072] The specific data obtained from the test is as follows: ; Microstructure characterization: See Figure 4 The image shows a metallographic microscopy comparison of cross-sections of MLCC products produced using the method of this invention and those produced using existing split-processing methods. The metallographic images of the experimental group chip cross-sections show that the ceramic dielectric layer is dense and continuous, the nickel inner electrode layer is uniformly distributed and exhibits a bright metallic luster, with no delamination, cracks, visible pores, or signs of oxidation. The metallographic images of the control group chip cross-sections show that the dielectric layer has obvious delamination cracks and pore defects, and a gray-black oxide layer appears at the edge of the nickel inner electrode.

[0073] in conclusion: The above data and microstructure characterization results show that the experimental group using the method of this invention exhibits significantly better performance than the control group, with a 71% reduction in carbon residue, an 84% reduction in delamination and cracking defect rate, a 6.8% increase in dielectric layer density, an 8.8% increase in dielectric constant, a 22% reduction in loss factor, a 75% increase in insulation resistance, and an 18% increase in breakdown voltage. Metallurgical microscopy observations indicate that the MLCC chip prepared by the method of this invention is significantly superior to the traditional discrete process in terms of microstructure integrity, internal electrode oxidation resistance, and dielectric layer density.

[0074] See Figure 5 The diagram shown is a schematic diagram of a modular post-processing system for MLCC debinding and sintering according to an embodiment of the present invention.

[0075] The MLCC debinding and sintering integrated post-processing system 200 described in this invention can be installed in an electronic device. Depending on the functions implemented, the MLCC debinding and sintering integrated post-processing system includes a green loading module 201, a temperature control module 202, an oxygen-containing debinding module 203, a reduction debinding module 204, a transition module 205, and a sintering cooling module 206. The module described in this invention can also be called a unit, which refers to a series of computer program segments that can be executed by the processor of an electronic device and can perform a fixed function, stored in the memory of the electronic device.

[0076] In this embodiment of the invention, the functions of each module / unit are as follows: The green body loading module 201 is used to place the cut MLCC ceramic green body into the heat treatment furnace and to introduce an oxygen-containing atmosphere into the heat treatment furnace. The temperature control module 202 is used to establish a multi-stage segmented heating curve for the ceramic green body, wherein the multi-stage segmented heating curve includes at least a low-temperature segment heating curve, a medium-temperature segment heating curve, and a high-temperature segment heating curve. The oxygen-containing adhesive removal module 203 is used to perform low-temperature and medium-temperature adhesive removal of the ceramic green body in the oxygen-containing atmosphere based on the low-temperature heating curve and the medium-temperature heating curve. The reduction and debinding module 204 is used to switch the oxygen-containing atmosphere to a reducing atmosphere or an inert atmosphere after the debinding in the medium-temperature section is completed, and to perform high-temperature debinding on the ceramic green body in the reducing atmosphere or the inert atmosphere based on the high-temperature section heating curve. The transition module 205 is used to perform transition heat preservation treatment on the ceramic green body after the glue removal is completed in the high temperature section, and to switch the reducing atmosphere or the inert atmosphere to a non-oxidizing sintering atmosphere during the transition heat preservation treatment. The sintering cooling module 206 is used to perform high-temperature sintering on the ceramic green body after the transition heat preservation treatment in the non-oxidizing sintering atmosphere, and after the high-temperature sintering is completed, to reduce the temperature inside the heat treatment furnace to room temperature, thereby obtaining the sintered MLCC chip.

[0077] In detail, the modules in the integrated debinding and sintering post-processing system 200 for MLCCs described in this embodiment of the invention employ the same methods as described above during use. Figure 1 The method described herein is the same as the integrated debinding and sintering post-processing method for MLCCs, and can produce the same technical effect, so it will not be repeated here.

[0078] In one embodiment, a computer device is provided, which may be a server or a client, and its internal structure diagram may be as follows: Figure 6As shown, the computer device includes a processor, memory, network interface, and database connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile and / or volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The network interface is used for communication with external clients via a network connection. When the computer program is executed by the processor, it implements the functions or steps of a post-processing method for integrated debinding and sintering of MLCCs on the server or client side.

[0079] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to perform the following steps: S1. Place the cut MLCC ceramic green body into a heat treatment furnace and introduce an oxygen-containing atmosphere into the heat treatment furnace. S2. Establish a multi-stage segmented heating curve for the ceramic green body, wherein the multi-stage segmented heating curve includes at least a low-temperature segment heating curve, a medium-temperature segment heating curve, and a high-temperature segment heating curve; S3. Based on the low-temperature section heating curve and the medium-temperature section heating curve, perform low-temperature section glue removal and medium-temperature section glue removal of the ceramic green body in the oxygen-containing atmosphere. S4. After the medium-temperature debinding is completed, the oxygen-containing atmosphere is switched to a reducing atmosphere or an inert atmosphere. Based on the high-temperature heating curve, the ceramic green body is debinded in the high-temperature stage in the reducing atmosphere or the inert atmosphere. S5. After the high-temperature section is debinded, the ceramic green body is subjected to a transition heat preservation treatment, and during the transition heat preservation treatment, the reducing atmosphere or the inert atmosphere is switched to a non-oxidizing sintering atmosphere. S6. The ceramic green body after the transition heat preservation treatment is sintered at high temperature in the non-oxidizing sintering atmosphere, and after the high temperature sintering is completed, the temperature in the heat treatment furnace is reduced to room temperature to obtain the sintered MLCC chip.

[0080] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor: S1. Place the cut MLCC ceramic green body into a heat treatment furnace and introduce an oxygen-containing atmosphere into the heat treatment furnace. S2. Establish a multi-stage segmented heating curve for the ceramic green body, wherein the multi-stage segmented heating curve includes at least a low-temperature segment heating curve, a medium-temperature segment heating curve, and a high-temperature segment heating curve; S3. Based on the low-temperature section heating curve and the medium-temperature section heating curve, perform low-temperature section glue removal and medium-temperature section glue removal of the ceramic green body in the oxygen-containing atmosphere. S4. After the medium-temperature debinding is completed, the oxygen-containing atmosphere is switched to a reducing atmosphere or an inert atmosphere. Based on the high-temperature heating curve, the ceramic green body is debinded in the high-temperature stage in the reducing atmosphere or the inert atmosphere. S5. After the high-temperature section is debinded, the ceramic green body is subjected to a transition heat preservation treatment, and during the transition heat preservation treatment, the reducing atmosphere or the inert atmosphere is switched to a non-oxidizing sintering atmosphere. S6. The ceramic green body after the transition heat preservation treatment is sintered at high temperature in the non-oxidizing sintering atmosphere, and after the high temperature sintering is completed, the temperature in the heat treatment furnace is reduced to room temperature to obtain the sintered MLCC chip.

[0081] It should be noted that the functions or steps that can be implemented by the computer-readable storage medium or computer device described above can be referred to the relevant descriptions on the server side and client side in the foregoing method embodiments. To avoid repetition, they will not be described one by one here.

[0082] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0083] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the system can be divided into different functional units or modules to complete all or part of the functions described above.

[0084] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0085] Finally, it should be noted that in the above embodiments, each embodiment can be combined with each other or independent. Deleting any one of them will not affect the technical implementation of other embodiments. The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A post-processing method for integrated debinding and sintering of MLCCs, characterized in that, The method includes: The cut MLCC ceramic green body is placed into a heat treatment furnace, and an oxygen-containing atmosphere is introduced into the heat treatment furnace. Establish a multi-stage segmented heating curve for the ceramic green body, wherein the multi-stage segmented heating curve includes at least a low-temperature segment heating curve, a medium-temperature segment heating curve, and a high-temperature segment heating curve; Based on the low-temperature heating curve and the medium-temperature heating curve, the low-temperature and medium-temperature debinding of the ceramic green body is carried out in the oxygen-containing atmosphere. After the medium-temperature debinding is completed, the oxygen-containing atmosphere is switched to a reducing atmosphere or an inert atmosphere. Based on the high-temperature heating curve, the ceramic green body is debinded in the high-temperature stage in the reducing atmosphere or the inert atmosphere. After the high-temperature section is debinded, the ceramic green body is subjected to a transition heat preservation treatment, and during the transition heat preservation treatment, the reducing atmosphere or the inert atmosphere is switched to a non-oxidizing sintering atmosphere. The ceramic green body after the transition heat treatment is sintered at high temperature in the non-oxidizing sintering atmosphere, and after the high-temperature sintering is completed, the temperature in the heat treatment furnace is reduced to room temperature to obtain the sintered MLCC chip.

2. The post-processing method for integrated debinding and sintering of MLCCs as described in claim 1, characterized in that, Based on the low-temperature heating curve and the medium-temperature heating curve, the low-temperature and medium-temperature debinding of the ceramic green body is performed in the oxygen-containing atmosphere, including: Thermogravimetric analysis was performed on the organic binder in the ceramic green body to determine the first decomposition temperature range of low molecular weight organic matter and the second decomposition temperature range of high molecular weight organic matter in the ceramic green body. The first temperature range of the low-temperature segment heating curve is set according to the first decomposition temperature range, and the second temperature range of the medium-temperature segment heating curve is set according to the second decomposition temperature range. In the oxygen-containing atmosphere, the furnace temperature corresponding to the ceramic green body is raised to the first temperature range according to the low-temperature section heating curve, and the ceramic green body is kept warm for a first preset time to allow the low molecular weight organic matter to be fully oxidized and decomposed, thereby obtaining the ceramic green body after low-temperature section debinding. After the low molecular weight organic matter is fully oxidized and decomposed, the furnace temperature is raised to the second temperature range according to the medium temperature range heating curve, and the ceramic green body is kept warm for a second preset time to allow the high molecular weight organic matter to be fully oxidized and decomposed, resulting in a ceramic green body after the medium temperature range binder is removed.

3. The post-processing method for integrated debinding and sintering of MLCCs as described in claim 2, characterized in that, Based on the low-temperature heating curve and the medium-temperature heating curve, the low-temperature and medium-temperature debinding of the ceramic green body is performed in the oxygen-containing atmosphere, further comprising: Real-time monitoring of the furnace exhaust gas concentration corresponding to the ceramic green body; When the concentration of exhaust gas in the furnace exceeds the preset concentration threshold, the fresh air volume of the oxygen-containing atmosphere is adjusted to maintain the concentration of exhaust gas in the furnace within the preset concentration range, thereby completing the low-temperature section and medium-temperature section glue removal of the ceramic green body.

4. The post-processing method for integrated debinding and sintering of MLCCs as described in claim 1, characterized in that, Based on the high-temperature heating curve, the ceramic green body undergoes high-temperature debinding in the reducing atmosphere or the inert atmosphere, including: In the reducing atmosphere or the inert atmosphere, the furnace temperature of the ceramic green body is raised to the high-temperature section debinding temperature according to the high-temperature section heating curve, so that the residual high molecular weight organic matter in the ceramic green body is decomposed and discharged to obtain a preliminary debinding green body. At the high-temperature debinding temperature, the pre-debinded green body is kept at a third preset time to further remove residual carbon from the ceramic green body, thus obtaining a ceramic green body after high-temperature debinding. The third preset duration is set according to the size of the ceramic green body, the organic matter content, and the target residual carbon content.

5. The post-processing method for integrated debinding and sintering of MLCCs as described in claim 1, characterized in that, After the adhesive is removed in the high-temperature section, the ceramic green body undergoes a transitional heat preservation treatment, including: After the high-temperature section glue removal is completed, the ceramic green body is cooled to a preset transition heat preservation temperature, or the ceramic green body is kept at the high-temperature section glue removal temperature. The ceramic green body is kept at the high-temperature section glue removal temperature or the transition heat preservation temperature for a preset transition time to obtain a transition heat preservation treated green body. The temperature difference between the transition insulation temperature and the high-temperature section adhesive discharge temperature is within ±50℃; the transition insulation temperature is preset according to the thermal stability temperature range of the constituent materials of the ceramic green body.

6. The post-processing method for integrated debinding and sintering of MLCCs as described in claim 1, characterized in that, High-temperature sintering of the ceramic green body after the transition holding treatment in the non-oxidizing sintering atmosphere includes: The ceramic green body after the transition heat preservation treatment is heated to the sintering temperature in the non-oxidizing sintering atmosphere at a preset sintering heating rate. The ceramic green body is held at the sintering temperature for a fourth preset time, so that the ceramic green body completes densification and shrinkage during the heating and holding process, and the sintered ceramic chip is obtained. The sintering heating rate is preset based on the thickness of the dielectric layer of the ceramic green body and the sintering activity of the ceramic powder; the fourth preset duration is preset based on the thickness of the dielectric layer of the ceramic green body and the sintering temperature.

7. The post-processing method for integrated debinding and sintering of MLCCs as described in claim 1, characterized in that, The oxygen-containing atmosphere is air or an oxygen-enriched atmosphere with an oxygen volume fraction of 5% to 21%; the reducing atmosphere or inert atmosphere is nitrogen, argon, or a mixture of nitrogen and hydrogen, and the hydrogen volume fraction in the mixture is ≤5%; the non-oxidizing sintering atmosphere is nitrogen or a mixture of nitrogen and hydrogen, and the oxygen volume fraction in the mixture is less than 10 ppm.

8. The post-processing method for integrated debinding and sintering of MLCCs as described in claim 1, characterized in that, Establishing the multi-stage segmented heating curve of the ceramic green body includes: Identify the types of organic binders in the ceramic green body, and determine the thermal decomposition characteristic temperature range of the ceramic green body based on the types of organic binders. Based on the thermal decomposition characteristic temperature range, the glue removal process of the ceramic green body is divided into a low-temperature section, a medium-temperature section, and a high-temperature section. The thickness of the dielectric layer and the internal electrode material of the ceramic green body are obtained to define the heating rate and holding time corresponding to each temperature stage; Based on the temperature stages, the heating rate, and the holding time, a multi-stage segmented heating curve for the ceramic green body is generated.

9. The post-processing method for integrated debinding and sintering of MLCCs as described in claim 1, characterized in that, The heat treatment furnace is an integrated box-type debinding and sintering furnace with controllable atmosphere, comprising a furnace body heating module, a vacuum system module, a gas input / output module, a multi-point temperature detection module, and a PLC control module.

10. The post-processing method for integrated debinding and sintering of MLCCs as described in claim 1, characterized in that, Before placing the cut MLCC ceramic green body into the heat treatment furnace, the process further includes: placing the ceramic green body in a medium containing zirconium powder or titanium dioxide powder for tumbling and milling treatment, so that a powder coating layer is formed on the surface of the ceramic green body.

Images